The Nature of Work in a Changing Society.

ERIC Educational Resources Information Center

Best, Fred

1985-01-01

Influences on the future world of work are considered: values and world views, knowledge and skills, management and organizational norms, general economic conditions, investment and savings, availability of raw materials, economic competition, and technological developments. Also discusses the rate of change and where transitions are expected to…

Impact analysis of automotive structures with distributed smart material systems

NASA Astrophysics Data System (ADS)

Peelamedu, Saravanan M.; Naganathan, Ganapathy; Buckley, Stephen J.

1999-06-01

New class of automobiles has structural skins that are quite different from their current designs. Particularly, new families of composite skins are developed with new injection molding processes. These skins while support the concept of lighter vehicles of the future, are also susceptible to damage upon impact. It is important that their design should be based on a better understanding on the type of impact loads and the resulting strains and damage. It is possible that these skins can be integrally designed with active materials to counter damages. This paper presents a preliminary analysis of a new class of automotive skins, using piezoceramic as a smart material. The main objective is to consider the complex system with, the skin to be modeled as a layered plate structure involving a lightweight material with foam and active materials imbedded on them. To begin with a cantilever beam structure is subjected to a load through piezoceramic and the resulting strain at the active material site is predicted accounting for the material properties, piezoceramic thickness, adhesive thickness including the effect of adhesives. A finite element analysis is carried out to compare experimental work. Further work in this direction would provide an analytical tool that will provide the basis for algorithms to predict and counter impacts on the future class of automobiles.

Curating NASA's Future Extraterrestrial Sample Collections: How Do We Achieve Maximum Proficiency?

NASA Technical Reports Server (NTRS)

McCubbin, Francis; Evans, Cynthia; Zeigler, Ryan; Allton, Judith; Fries, Marc; Righter, Kevin; Zolensky, Michael

2016-01-01

The Astromaterials Acquisition and Curation Office (henceforth referred to herein as NASA Curation Office) at NASA Johnson Space Center (JSC) is responsible for curating all of NASA's extraterrestrial samples. Under the governing document, NASA Policy Directive (NPD) 7100.10E "Curation of Extraterrestrial Materials", JSC is charged with "The curation of all extraterrestrial material under NASA control, including future NASA missions." The Directive goes on to define Curation as including "... documentation, preservation, preparation, and distribution of samples for research, education, and public outreach." Here we describe some of the ongoing efforts to ensure that the future activities of the NASA Curation Office are working towards a state of maximum proficiency.

Scoping Future Policy Dynamics in Raw Materials Through Scenarios Testing

NASA Astrophysics Data System (ADS)

Correia, Vitor; Keane, Christopher; Sturm, Flavius; Schimpf, Sven; Bodo, Balazs

2017-04-01

The International Raw Materials Observatory (INTRAW) project is working towards a sustainable future for the European Union in access to raw materials, from an availability, economical, and environmental framework. One of the major exercises for the INTRAW project is the evaluation of potential future scenarios for 2050 to frame economic, research, and environmental policy towards a sustainable raw materials supply. The INTRAW consortium developed three possible future scenarios that encompass defined regimes of political, economic, and technological norms. The first scenario, "Unlimited Trade," reflects a world in which free trade continues to dominate the global political and economic environment, with expectations of a growing demand for raw materials from widely distributed global growth. The "National Walls" scenario reflects a world where nationalism and economic protectionism begins to dominate, leading to stagnating economic growth and uneven dynamics in raw materials supply and demand. The final scenario, "Sustainability Alliance," examines the dynamics of a global political and economic climate that is focused on environmental and economic sustainability, leading towards increasingly towards a circular raw materials economy. These scenarios were reviewed, tested, and provided simulations of impacts with members of the Consortium and a panel of global experts on international raw materials issues which led to expected end conditions for 2050. Given the current uncertainty in global politics, these scenarios are informative to identifying likely opportunities and crises. The details of these simulations and expected responses to the research demand, technology investments, and economic components of raw materials system will be discussed.

Building a Sustainable Future

NASA Technical Reports Server (NTRS)

Jones, Clyde S.; Hessler, Susan

2010-01-01

This poster presentation shows some of the personnel at work in the Materials and Processes Laboratory at NASA's Marshall Space Flight Center. They are shown studying materials of all kinds and the processes for manufacturing. The purpose of the poster is to inspire young people to become tomorrow's engineers, scientists, technicians or support specialist at NASA.

National Forum on the Future of Automated Materials Processing in US Industry: The Role of Sensors. Report of a workshop (1st) held at Santa Barbara, California on December 16-17, 1985

NASA Astrophysics Data System (ADS)

Yolken, H. T.; Mehrabian, R.

1985-12-01

These are the proceedings of the workshop A National Forum on the Future of Automated Materials Processing in U.S. Industry - The Role of Sensors. This is the first of two workshops to be sponsored by the Industrial Research Institute and the White House Office of Science and Technology Policy, Committee on Materials Working Group on Automation of Materials Processing. The second workshop will address the other two key components required for automated materials processing, process models and artificial intelligence coupled with computer integration of the system. The objective of these workshops is to identify and assess important issues afecting the competitive position of U.S. industry related to its ability to automate production processes for basic and advanced materials and to develop approaches for improved capability through cooperative R&D and associated efforts.

Nanostructured carbon and carbon nanocomposites for electrochemical energy storage applications.

PubMed

Su, Dang Sheng; Schlögl, Robert

2010-02-22

Electrochemical energy storage is one of the important technologies for a sustainable future of our society, in times of energy crisis. Lithium-ion batteries and supercapacitors with their high energy or power densities, portability, and promising cycling life are the cores of future technologies. This Review describes some materials science aspects on nanocarbon-based materials for these applications. Nanostructuring (decreasing dimensions) and nanoarchitecturing (combining or assembling several nanometer-scale building blocks) are landmarks in the development of high-performance electrodes for with long cycle lifes and high safety. Numerous works reviewed herein have shown higher performances for such electrodes, but mostly give diverse values that show no converging tendency towards future development. The lack of knowledge about interface processes and defect dynamics of electrodes, as well as the missing cooperation between material scientists, electrochemists, and battery engineers, are reasons for the currently widespread trial-and-error strategy of experiments. A concerted action between all of these disciplines is a prerequisite for the future development of electrochemical energy storage devices.

Incorporating Polymer Science Lecture Topics into the Beginning Organic Chemistry Course to Engage Students' Interest in Current and Future Applications

ERIC Educational Resources Information Center

Howell, Bob A.

2017-01-01

The impact of polymeric materials on the well-being of citizens of the modern world is enormous. These materials enhance virtually every facet of life--from clothing and personal care items to housing and transportation. Yet despite this, and the fact that most chemists work in a polymer or polymer-related area, polymeric materials have…

Analytical and Radiochemistry for Nuclear Forensics

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

Steiner, Robert Ernest; Dry, Donald E.; Kinman, William Scott

Information about nonproliferation nuclear forensics, activities in forensics at Los Alamos National Laboratory, radio analytical work at LANL, radiochemical characterization capabilities, bulk chemical and materials analysis capabilities, and future interests in forensics interactions.

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.

Earth-based construction material field tests characterization in the Alto Douro Wine Region

NASA Astrophysics Data System (ADS)

Cardoso, Rui; Pinto, Jorge; Paiva, Anabela; Lanzinha, João Carlos

2017-12-01

The Alto Douro Wine Region, located in the northeast of Portugal, a UNESCO World Heritage Site, presents an abundant vernacular building heritage. This building technology is based on a timber framed structure filled with a composite earth-based material. A lack of scientific studies related to this technology is evident, furthermore, principally in rural areas, this traditional building stock is highly deteriorated and damaged because of the rareness of conservation and strengthening works, which is partly related to the non-engineered character of this technology and to the knowledge loosed on that technique. Those aspects motivated the writing of this paper, whose main purpose is the physical and chemical characterization of the earth-based material applied in the tabique buildings of that region through field tests. Consequently, experimental work was conducted and the results obtained allowed, among others, the proposal of a series of adequate field tests. At our knowledge, this is the first time field tests are undertaken for tabique technology. This information will provide the means to assess the suitability of a given earth-based material with regards to this technology. The knowledge from this study could also be very useful for the development of future normative documents and as a reference for architects and engineers that work with this technology to guide and regulate future conservation, rehabilitation or construction processes helping to preserve this important legacy.

Low-Dimensional Nanomaterials and Molecular Dielectrics for Radiation-Hard Electronics

NASA Astrophysics Data System (ADS)

McMorrow, Julian

The electronic materials research driving Moore's law has provided several decades of increasingly powerful yet simultaneously miniaturized computer technologies. As we approach the physical and practical limits of what can be accomplished with silicon electronics, we look to new materials to drive innovation in future electronic applications. New materials paradigms require the development of understanding from first principles to the demonstration of applications that comes with mature technologies. Semiconducting single-walled carbon nanotubes (SWCNTs), single- and few-layer molybdenum disulfide (MoS2) and self-assembled nanodielectric (SAND) gate materials have all made significant impacts in the research field of unconventional electronic materials. The materials selection, interfaces between materials, processing steps to assemble them, and their interaction with their environment all have significant bearing on the operation of the overall device. Operating in harsh radiation environments, like those of satellites orbiting the Earth, present unique challenges to the functionality and reliability of electronic devices. Because the future of space-bound electronics is often informed by the technology of terrestrial devices, a proactive approach is adopted to identify and understand the radiation response of new materials systems as they emerge and develop. The work discussed here drives the innovation and development of multiple nanomaterial based electronic technologies while simultaneously exploring their relevant radiation response mechanisms. First, collaborative efforts result in the demonstration of a SWCNT-based circuit technology that is solution processed, large-area, and compatible with flexible substrates. The statistical characterization of SWCNT transistors enables the development of robust doping and encapsulation schemes, which make the SWCNT circuits stable, scalable, and low-power. These SWCNTs are then integrated into static random access memory (SRAM) cells, an accomplishment that illustrates the technological relevance of this work by implementing a highly utilized component of modern day computing. Next, these SRAM devices demonstrate functionality as true random number generators (TRNGs), which are critical components in cryptography and encryption. The randomness of these SWCNT TRNGs is verified by a suite of statistical tests. This achievement has implications for securing data and communication in future solution-processed, large-area, flexible electronics. The unprecedented integration achieved by the underlying SWCNT doping and encapsulation motivates the study of this technology in a radiation environment. Doing so results in an understanding of the fundamental charge trapping mechanisms responsible for the radiation response in this system. The integrated nature of these devices enables, for the first time, the observation of system-level effects in a SWCNT integrated circuit technology. This technology is found to be total ionizing dose-hard, a promising result for the adoption of SWCNTs in future space-bound applications. Compared to SWCNTs, the field of MoS2 electronics is relatively nascent. As a result, studies of radiation effects in MoS2 devices focus on the fundamental mechanisms at play in the materials system. Here, we reveal the critical role of atmospheric adsorbates in the radiation effects of MoS2 transistors by measuring their response to vacuum ultraviolet radiation. These results highlight the importance of controlling the atmosphere of MoS2 devices during irradiation. Furthermore, we make recommendations for radiation-hard MoS2-based devices in the future as the technology continues to mature. One such recommendation is the incorporation of specialized dielectrics with proven radiation hardness. To this end, we address the materials integration challenge of incorporating SAND gate dielectrics on arbitrary substrates. We explore a novel approach for preparing metal substrates for SAND deposition, supporting the SAND superlattice structure and its superlative electronic properties on a metal surface. This result is critical for conducting fundamental transport studies when integrating SAND with novel semiconductor materials, as well as enabling complex circuit integration and SAND on flexible substrates. Altogether, these works drive the integration of novel nanoelectronic materials for future electronics while providing an understanding of their varying radiation response mechanisms to enable their adoption in future space-bound applications.

Power accounting of plasma discharges in the linear device Proto-MPEX

NASA Astrophysics Data System (ADS)

Showers, M.; Piotrowicz, P. A.; Beers, C. J.; Biewer, T. M.; Caneses, J.; Canik, J.; Caughman, J. B. O.; Donovan, D. C.; Goulding, R. H.; Lumsdaine, A.; Kafle, N.; Owen, L. W.; Rapp, J.; Ray, H.

2018-06-01

Plasma material interaction (PMI) studies are crucial to the successful development of future fusion reactors. Prototype Material Plasma Exposure eXperiment (Proto-MPEX) is a prototype design for the MPEX, a steady-state linear device being developed to study PMI. The primary purpose of Proto-MPEX is developing the plasma heating source concepts for MPEX. A power accounting study of Proto-MPEX works to identify machine operating parameters that could improve its performance, thereby increasing its PMI research capabilities, potentially impacting the MPEX design concept. To build a comprehensive power balance, an analysis of the helicon region has been performed implementing a diagnostic suite and software modeling to identify mechanisms and locations of heat loss from the main plasma. Of the 106.3 kW of input power, up to 90.5% of the power has been accounted for in the helicon region. When the analysis was extended to encompass the device to its end plates, 49.2% of the input power was accounted for and verified diagnostically. Areas requiring further diagnostic analysis are identified. The required improvements will be implemented in future work. The data acquisition and analysis processes will be streamlined to form a working model for future power balance studies of Proto-MPEX. ).

Report of the In Situ Resources Utilization Workshop

NASA Technical Reports Server (NTRS)

Fairchild, Kyle (Editor); Mendell, Wendell W. (Editor)

1988-01-01

The results of a workshop of 50 representatives from the public and private sector which investigated the potential joint development of the key technologies and mechanisms that will enable the permanent habitation of space are presented. The workshop is an initial step to develop a joint public/private assessment of new technology requirements of future space options, to share knowledge on required technologies that may exist in the private sector, and to investigate potential joint technology development opportunities. The majority of the material was produced in 5 working groups: (1) Construction, Assembly, Automation and Robotics; (2) Prospecting, Mining, and Surface Transportation; (3) Biosystems and Life Support; (4) Materials Processing; and (5) Innovative Ventures. In addition to the results of the working groups, preliminary technology development recommendations to assist in near-term development priority decisions are presented. Finally, steps are outlined for potential new future activities and relationships among the public, private, and academic sectors.

Photocatalytic materials and technologies for air purification.

PubMed

Ren, Hangjuan; Koshy, Pramod; Chen, Wen-Fan; Qi, Shaohua; Sorrell, Charles Christopher

2017-03-05

Since there is increasing concern for the impact of air quality on human health, the present work surveys the materials and technologies for air purification using photocatalytic materials. The coverage includes (1) current photocatalytic materials for the decomposition of chemical contaminants and disinfection of pathogens present in air and (2) photocatalytic air purification systems that are used currently and under development. The present work focuses on five main themes. First, the mechanisms of photodegradation and photodisinfection are explained. Second, system designs for photocatalytic air purification are surveyed. Third, the photocatalytic materials used for air purification and their characteristics are considered, including both conventional and more recently developed photocatalysts. Fourth, the methods used to fabricate these materials are discussed. Fifth, the most significant coverage is devoted to materials design strategies aimed at improving the performance of photocatalysts for air purification. The review concludes with a brief consideration of promising future directions for materials research in photocatalysis. Copyright © 2016 Elsevier B.V. All rights reserved.

Characterization of DWPF recycle condensate materials

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

Bannochie, C. J.; Adamson, D. J.; King, W. D.

2015-04-01

A Defense Waste Processing Facility (DWPF) Recycle Condensate Tank (RCT) sample was delivered to the Savannah River National Laboratory (SRNL) for characterization with particular interest in the concentration of I-129, U-233, U-235, total U, and total Pu. Since a portion of Salt Batch 8 will contain DWPF recycle materials, the concentration of I-129 is important to understand for salt batch planning purposes. The chemical and physical characterizations are also needed as input to the interpretation of future work aimed at determining the propensity of the RCT material to foam, and methods to remediate any foaming potential. According to DWPF themore » Tank Farm 2H evaporator has experienced foaming while processing DWPF recycle materials. The characterization work on the RCT samples has been completed and is reported here.« less

Rheology of Soft Materials

NASA Astrophysics Data System (ADS)

Chen, Daniel T. N.; Wen, Qi; Janmey, Paul A.; Crocker, John C.; Yodh, Arjun G.

2010-04-01

Research on soft materials, including colloidal suspensions, glasses, pastes, emulsions, foams, polymer networks, liquid crystals, granular materials, and cells, has captured the interest of scientists and engineers in fields ranging from physics and chemical engineering to materials science and cell biology. Recent advances in rheological methods to probe mechanical responses of these complex media have been instrumental for producing new understanding of soft matter and for generating novel technological applications. This review surveys these technical developments and current work in the field, with partial aim to illustrate open questions for future research.

Autonomous System for MISSE Temperature Measurements

NASA Technical Reports Server (NTRS)

Harvey, G. A.; Lash, T. J.; Kinard, W. H.; Bull, K.; deGeest, F.

2001-01-01

The Materials International Space Station Experiment (MISSE) is scheduled to be deployed during the summer of 2001. This experiment is a cooperative endeavor by NASA-LaRC, NASA-GRC, NASA MSFC, NASA-JSC, the Materials Laboratory at the Air Force Research Laboratory, and the Boeing Phantom Works. The objective of the experiment is to evaluate performance, stability, and long term survivability of materials and components planned for use by NASA and DOD on future LEO, synchronous orbit, and interplanetary space missions. Temperature is an important parameter in the evaluation of space environmental effects on materials.

Advanced Materials for Exploration Task Research Results

NASA Technical Reports Server (NTRS)

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

2008-01-01

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

Episodic future thinking: the role of working memory and inhibition on age-related differences.

PubMed

Zavagnin, Michela; De Beni, Rossana; Borella, Erika; Carretti, Barbara

2016-02-01

The ability to remember past events and imagine future events (episodic future thinking-EFT) has been shown to decline with aging. However, only few studies have analyzed the cognitive mechanisms involved in EFT in both young and older adults. The present study examined the role of working memory and inhibition on age-related differences between young and older adults in EFT, in response to short sentences reflecting common events, some of which were repeated in both conditions (past and future). Thirty-seven young and 36 older adults completed an adapted version of the autobiographical interview, in which sentences were presented. Results showed that processing resources explained a significant part of the variance in the amount of details; in particular, inhibition explained the amount of external details produced in the future condition. In addition, using sentences, the older group did not differ from the young adults in terms of the proportion of internal details recalled in the past condition, whereas they produced a lower proportion of internal details in the future condition. The effect of using structured material was reinforced by repeating some sentences in the past. Further, only older adults rated the remembered episodes as more emotionally salient and relevant than the imagined ones. Age-related differences between young and older adults in EFT appear to depend on the type of material used, on basic mechanisms of cognition, and are characterized by both quantitative and qualitative differences.

Comparison of tokamak behaviour with tungsten and low-Z plasma facing materials

NASA Astrophysics Data System (ADS)

Philipps, V.; Neu, R.; Rapp, J.; Samm, U.; Tokar, M.; Tanabe, T.; Rubel, M.

2000-12-01

Graphite wall materials are used in present day fusion devices in order to optimize plasma core performance and to enable access to a large operational space. A large physics database exists for operation with these plasma facing materials, which also indicate their use in future devices with extended burn times. The radiation from carbon impurities in the edge and divertor regions strongly helps to reduce the peak power loads on the strike areas, but carbon radiation also supports the formation of MARFE instabilities which can hinder access to high densities. The main concerns with graphite are associated with its strong chemical affinity to hydrogen, which leads to chemical erosion and to the formation of hydrogen-rich carbon layers. These layers can store a significant fraction of the total tritium fuel, which might prevent the use of these materials in future tritium devices. High-Z plasma facing materials are much more advantageous in this sense, but these advantages compete with the strong poisoning of the plasma if they enter the plasma core. New promising experiences have been obtained with high-Z wall materials in several devices, about which a survey is given in this paper and which also addresses open questions for future research and development work.

Project EFFECT. Energy for the Future: Education, Conservation, Training. Curriculum Guides for the Training of Energy Extension Agents. A Working Paper, Section II: Technical Training.

ERIC Educational Resources Information Center

Indiana Univ., South Bend. Center for Energy Conservation.

This second of four sections in a curriculum guide for training energy extension agents contains general introductory materials, an overview of the total curriculum, and eight modules: Alternative Energy Sources (Solar and Wood), Basic Graphics and Blueprint Reading, Building Materials, Electricity, Introduction to Cooling Systems, Introduction to…

Teaching with Stereoscopic Video: Opportunities and Challenges

NASA Astrophysics Data System (ADS)

Variano, Evan

2017-11-01

I will present my work on creating stereoscopic videos for fluid pedagogy. I discuss a variety of workflows for content creation and a variety of platforms for content delivery. I review the qualitative lessons learned when teaching with this material, and discuss outlook for the future. This work was partially supported by the NSF award ENG-1604026 and the UC Berkeley Student Technology Fund.

Introduction of performance boosters like Ge as channel material for the future of CMOS

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

Samia, Slimani, E-mail: slimani.samia@gmail.com; Laboratoire de Modélisation et Méthodes de calcul LMMC,20002 Saida; Bouaza, Djellouli, E-mail: djelbou@hotmail.fr

High mobility materials are being considered to replace Si in the channel to achieve higher drive currents and switching speeds. Ge is one of new attractive channel materials that require CMOS scaling For future technology nodes and future high performance P-MOSFETS, we have studied a nanoscale SOI DG MOSFETs using quantum simulation approach on DG MOSFETs within the variation of Ge channel concentration and in the presence of source and drain doping by replacing Silicon in the channel by Ge using various dielectric constant. The use of high mobility channel (like Ge) to maximize the MOSFET IDsat and simultaneously circumventmore » the poor electrostatic control to suppress short-channel effects and enhance source injection velocity. The leakage current (I{sub off}) can be controlled by different gates oxide thickness more ever the required threshold voltage (V{sub TH}) can be achieved by keeping gate work function and altering the doping channel.« less

Synthesis and Characterization of Manganese Sponge doped with TiO2

NASA Astrophysics Data System (ADS)

Mallikarjun, patil

2017-06-01

The aviation and mechanical industry has seen tremendous growth in recent years. While these trends only continue, the materials on development of better fabrication technologies. Spongy materials are projected as favourable materials for the future as porous in nature. The current paper devotes to enhance mechanical properties by the use of Manganese sponge doped with TiO2 possess an outstanding array of properties not readily achievable with other materials. Samples were synthesized by Kroll process and solid-state reaction. The specified materials compares well with the presently used aeromechanical materials in all terms. The scope for further research work in this area will be outlined.

Monte Carlo Treatment of Displacement Damage in Bandgap Engineered HgCdTe Detectors

NASA Technical Reports Server (NTRS)

Fodness, Bryan C.; Marshall, Paul W.; Reed, Robert A.; Jordan, Thomas M.; Pickel, James C.; Jun, Insoo; Xapsos, Michael A.; Burke, Edward A.

2003-01-01

The conclusion are: 1. Description of NIEL calculation for short, mid, and longwave HgCdTe material compositions. 2. Full recoil spectra details captured and analyzed Importance of variance in high Z materials. 3. Can be applied directly to calculate damage distributions in arrays. 4. Future work will provide comparisons of measured array damage with calculated NIEL and damage energy distributions. 5. Technique to assess the full recoil spectrum behavior is extendable to other materials.

Carbon Nanotube-Enhanced Carbon-Phenenolic Ablator Material

NASA Technical Reports Server (NTRS)

Kikolaev, P.; Stackpoole, M.; Fan, W.; Cruden, B. A.; Waid, M.; Moloney, P.; Arepalli, S.; Arnold, J.; Partridge, H.; Yowell, L.

2006-01-01

This viewgraph presentation reviews the use of PICA (phenolic impregnated carbon ablator) as the selected material for heat shielding for future earth return vehicles. It briefly reviews the manufacturing of PICA and the advantages for the use of heat shielding, and then explains the reason for using Carbon Nanotubes to improve strength of phenolic resin that binds carbon fibers together. It reviews the work being done to create a carbon nanotube enhanced PICA. Also shown are various micrographic images of the various PICA materials.

Atomic Oxygen Task

NASA Technical Reports Server (NTRS)

Hadaway, James B.

1997-01-01

This report details work performed by the Center for Applied Optics (CAO) at the University of Alabama in Huntsville (UAH) on the contract entitled 'Atomic Oxygen Task' for NASA's Marshall Space Flight Center (contract NAS8-38609, Delivery Order 109, modification number 1). Atomic oxygen effects on exposed materials remain a critical concern in designing spacecraft to withstand exposure in the Low Earth Orbit (LEO) environment. The basic objective of atomic oxygen research in NASA's Materials & Processes (M&P) Laboratory is to provide the solutions to material problems facing present and future space missions. The objective of this work was to provide the necessary research for the design of specialized experimental test configurations and development of techniques for evaluating in-situ space environmental effects, including the effects of atomic oxygen and electromagnetic radiation on candidate materials. Specific tasks were performed to address materials issues concerning accelerated environmental testing as well as specifically addressing materials issues of particular concern for LDEF analysis and Space Station materials selection.

US Air Force perspective on validated NDE - Past, present, and future

NASA Astrophysics Data System (ADS)

Lindgren, Eric A.

2016-02-01

The concept of inspection has accompanied aviation since the work of the Wright Brothers. Inspection for both initial quality/materials acceptance and readiness for flight have been coupled with US Air Force (USAF) since its inception as the US Army Signal Corps. Initial nondestructive evaluation work expanded beyond visual inspection to include radiography and magnetic particle in the 1920's and 1930's as air frames transitioned to metal and engines used higher strength steels. Within the USAF Research and Development community, a Nondestructive Test Section was stood up in 1952 and the Nondestructive Evaluation Branch (NDE) was established in 1974. In 2012 the name was changed to the Materials State Awareness Branch. This name change reflects the evolution from a primary focus on inspections for damage and defects in materials to the characterization of the underlying materials structure that governs properties of the materials of interest for Air Force applications.

Advanced ceramic matrix composite materials for current and future propulsion technology applications

NASA Astrophysics Data System (ADS)

Schmidt, S.; Beyer, S.; Knabe, H.; Immich, H.; Meistring, R.; Gessler, A.

2004-08-01

Current rocket engines, due to their method of construction, the materials used and the extreme loads to which they are subjected, feature a limited number of load cycles. Various technology programmes in Europe are concerned, besides developing reliable and rugged, low cost, throwaway equipment, with preparing for future reusable propulsion technologies. One of the key roles for realizing reusable engine components is the use of modern and innovative materials. One of the key technologies which concern various engine manufacturers worldwide is the development of fibre-reinforced ceramics—ceramic matrix composites. The advantages for the developers are obvious—the low specific weight, the high specific strength over a large temperature range, and their great damage tolerance compared to monolithic ceramics make this material class extremely interesting as a construction material. Over the past years, the Astrium company (formerly DASA) has, together with various partners, worked intensively on developing components for hypersonic engines and liquid rocket propulsion systems. In the year 2000, various hot-firing tests with subscale (scale 1:5) and full-scale nozzle extensions were conducted. In this year, a further decisive milestone was achieved in the sector of small thrusters, and long-term tests served to demonstrate the extraordinary stability of the C/SiC material. Besides developing and testing radiation-cooled nozzle components and small-thruster combustion chambers, Astrium worked on the preliminary development of actively cooled structures for future reusable propulsion systems. In order to get one step nearer to this objective, the development of a new fibre composite was commenced within the framework of a regionally sponsored programme. The objective here is to create multidirectional (3D) textile structures combined with a cost-effective infiltration process. Besides material and process development, the project also encompasses the development of special metal/ceramic and ceramic/ceramic joining techniques as well as studying and verifying non destructive investigation processes for the purpose of testing components.

Investigation of surface topography and stiffness on adhesion and neurites extension of PC12 cells on crosslinked silica aerogel substrates

PubMed Central

Lynch, Kyle J.; Skalli, Omar

2017-01-01

Fundamental understanding and characterization of neural response to substrate topography is essential in the development of next generation biomaterials for nerve repair. Aerogels are a new class of materials with great potential as a biomaterial. In this work, we examine the extension of neurites by PC12 cells plated on matrigel-coated and collagen-coated mesoporous aerogel surfaces. We have successfully established the methodology for adhesion and growth of PC12 cells on polyurea crosslinked silica aerogels. Additionally, we have quantified neurite behaviors and compared their response on aerogel substrates with their behavior on tissue culture (TC) plastic, and polydimethylsiloxane (PDMS). We found that, on average, PC12 cells extend longer neurites on crosslinked silica aerogels than on tissue culture plastic, and, that the average number of neurites per cluster is lower on aerogels than on tissue culture plastic. Aerogels are an attractive candidate for future development of smart neural implants and the work presented here creates a platform for future work with this class of materials as a substrate for bioelectronic interfacing. PMID:29049304

Investigation of surface topography and stiffness on adhesion and neurites extension of PC12 cells on crosslinked silica aerogel substrates.

PubMed

Lynch, Kyle J; Skalli, Omar; Sabri, Firouzeh

2017-01-01

Fundamental understanding and characterization of neural response to substrate topography is essential in the development of next generation biomaterials for nerve repair. Aerogels are a new class of materials with great potential as a biomaterial. In this work, we examine the extension of neurites by PC12 cells plated on matrigel-coated and collagen-coated mesoporous aerogel surfaces. We have successfully established the methodology for adhesion and growth of PC12 cells on polyurea crosslinked silica aerogels. Additionally, we have quantified neurite behaviors and compared their response on aerogel substrates with their behavior on tissue culture (TC) plastic, and polydimethylsiloxane (PDMS). We found that, on average, PC12 cells extend longer neurites on crosslinked silica aerogels than on tissue culture plastic, and, that the average number of neurites per cluster is lower on aerogels than on tissue culture plastic. Aerogels are an attractive candidate for future development of smart neural implants and the work presented here creates a platform for future work with this class of materials as a substrate for bioelectronic interfacing.

An Electrothermal Plasma Source Developed for Simulation of Transient Heat Loads in Future Large Fusion Devices

NASA Astrophysics Data System (ADS)

Gebhart, Trey; Baylor, Larry; Winfrey, Leigh

2016-10-01

The realization of fusion energy requires materials that can withstand high heat and particle fluxes at the plasma material interface. In this work, an electrothermal (ET) plasma source has been designed as a possible transient heat flux source for a linear plasma material interaction device. An ET plasma source operates in the ablative arc regime, which is driven by a DC capacitive discharge. The current travels through the 4mm bore of a boron nitride liner and subsequently ablates and ionizes the liner material. This results in a high density plasma with a large unidirectional bulk flow out of the source exit. The pulse length for the ET source has been optimized using a pulse forming network to have a duration of 1ms at full-width half maximum. The peak currents and maximum source energies seen in this system are 2kA and 5kJ. The goal of this work is to show that the ET source produces electron densities and heat fluxes that are comparable to transient events in future large magnetic confinement fusion devices. Heat flux, plasma temperature, and plasma density were determined for each test shot using infrared imaging and optical spectroscopy techniques. This work will compare the ET source output (heat flux, temperature, and density) with and without an applied magnetic field. Research sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U. S. Department of Energy.

Global Oncology; Harvard Global Health Catalyst summit lecture notes

NASA Astrophysics Data System (ADS)

Ngwa, Wilfred; Nguyen, Paul

2017-08-01

The material presented in this book is at the cutting-edge of global oncology and provides highly illuminating examples, addresses frequently asked questions, and provides information and a reference for future work in global oncology care, research, education, and outreach.

Oil and Hazardous Materials Spill Response Technology Development, Strategic Plan

DTIC Science & Technology

2012-05-01

the pollutant can be recovered, burned, or dispersed . Objectives:  Develop the means to divert and contain sinking and suspended oils in order to...Research and Development Center 1 Chelsea Street New London, CT 06320 10. Work Unit No. (TRAIS) 11. Contract or Grant No. 12...similar analysis of prevention efforts should be carried out in the future. 17. Key Words oil, hazardous material, oil spill, pollution

Public Policy and Futures Bibliography: A Select List of Canadian, American, and Other Book-Length Materials, 1970 to 1980, Including Highly Selected Works Published Between 1949 and 1969.

ERIC Educational Resources Information Center

Stevenson, Hugh A., Comp.

This bibliography of public policy and general futures literature is intended primarily for educators and educational policy makers in Canada and particularly those who are responsible for shaping education in Ontario. The bulk of the entries are items published in Canada and America between 1970 and 1980. Also included are some selected items…

Assessing Economic Modulation of Future Critical Materials Use: The Case of Automotive-Related Platinum Group Metals.

PubMed

Zhang, Jingshu; Everson, Mark P; Wallington, Timothy J; Field, Frank R; Roth, Richard; Kirchain, Randolph E

2016-07-19

Platinum-group metals (PGMs) are technological and economic enablers of many industrial processes. This important role, coupled with their limited geographic availability, has led to PGMs being labeled as "critical materials". Studies of future PGM flows have focused on trends within material flows or macroeconomic indicators. We complement the previous work by introducing a novel technoeconomic model of substitution among PGMs within the automotive sector (the largest user of PGMs) reflecting the rational response of firms to changing prices. The results from the model support previous conclusions that PGM use is likely to grow, in some cases strongly, by 2030 (approximately 45% for Pd and 5% for Pt), driven by the increasing sales of automobiles. The model also indicates that PGM-demand growth will be significantly influenced by the future Pt-to-Pd price ratio, with swings of Pt and Pd demand of as much as 25% if the future price ratio shifts higher or lower even if it stays within the historic range. Fortunately, automotive catalysts are one of the more effectively recycled metals. As such, with proper policy support, recycling can serve to meet some of this growing demand.

Propellant material compatibility program and results

NASA Technical Reports Server (NTRS)

Toth, L. R.; Cannon, W. A.; Coulbert, C. D.; Long, H. R.

1976-01-01

The effects of long-term (up to 10 years) contact of inert materials with earth-storable propellants were studied for the purpose of designing chemical propulsion system components that can be used for current as well as future planetary spacecraft. The primary experimental work, and results to date are reported. Investigations include the following propellants: hydrazine, hydrazine-hydrazine nitrate blends, monomethyl-hydrazine, and nitrogen tetroxide. Materials include: aluminum alloys, corrosion-resistant steels, and titanium alloys. More than 700 test specimen capsules were placed in long-term storage testing at 43 C in the special material compatibility facility. Material ratings relative to the 10-year requirement have been assigned.

Hierarchical nanostructures for functional materials.

PubMed

Qin, Zhao; Buehler, Markus J

2018-07-13

Naturally occurring biomaterials often have amazing functions, such as mechanical, thermal, electromagnetic, biological, optical and acoustic. These superior performances are often due to their hierarchical organizations of natural materials, starting from the nanoscopic scale and extending all the way to the macroscopic level. This topical issue features articles dedicated to understanding, designing and characterizing complex de novo hierarchical materials for a variety of applications. This research area is quickly evolving, and we hope that future work will drive the rational designs of innovative functional materials and generate deep impacts to broad engineering fields that address major societal challenges and needs.

Hierarchical nanostructures for functional materials

NASA Astrophysics Data System (ADS)

Qin, Zhao; Buehler, Markus J.

2018-07-01

Naturally occurring biomaterials often have amazing functions, such as mechanical, thermal, electromagnetic, biological, optical and acoustic. These superior performances are often due to their hierarchical organizations of natural materials, starting from the nanoscopic scale and extending all the way to the macroscopic level. This topical issue features articles dedicated to understanding, designing and characterizing complex de novo hierarchical materials for a variety of applications. This research area is quickly evolving, and we hope that future work will drive the rational designs of innovative functional materials and generate deep impacts to broad engineering fields that address major societal challenges and needs.

Syntactic Metals: A Survey of Current Technology

NASA Technical Reports Server (NTRS)

Erikson, Ray

2003-01-01

Syntactic metals are a relatively new development in materials science. Several approaches to synthesizing these materials have been tried, and the handful of researchers in this field are beginning to make progress in defining useful compositions and processes. Syntactic metals can provide materials with dramatically improved specific strength and stiffness over their parent alloys, while retaining the isotropy that makes ordinary metals preferable to fiber-reinforced laminated composites in many applications. This paper reviews syntactic material concepts in general, the current state of the art (including the author's own work in syntactic aluminum), and the direction of future developments.

Efficiency of Cs-free materials for negative ion production in H2 and D2 plasmas

NASA Astrophysics Data System (ADS)

Friedl, R.; Kurutz, U.; Fantz, U.

2017-08-01

High power negative ion sources use caesium to reduce the work function of the converter surface which significantly increases the negative ion yield. Caesium, however, is a very reactive alkali-metal and shows complex redistribution dynamics in consequence of plasma-surface-interaction. Thus, maintaining a stable and homogenous low work function surface is a demanding task, which is not easily compatible with the RAMI issues (reliability, availability, maintainability, inspectability) for a future DEMO fusion reactor. Hence, Cs-free alternative materials for efficient negative ion formation are desirable. At the laboratory experiment HOMER materials which are referred to as promising are investigated under identical and ion source relevant parameters: the refractory metals Ta and W, non-doped and boron-doped diamond as well as materials with inherent low work function (lanthanum-doped molybdenum, MoLa and lanthanum hexaboride, LaB6). The results are compared to the effect of in-situ caesiation, which at HOMER leads to a maximal increase of the negative ion density by a factor of 2.5. Among the examined samples low work function materials are most efficient. In particular, MoLa leads to an increase of almost 50 % compared to pure volume formation. The difference to a caesiated surface can be attributed to the still higher work function of MoLa, which is expected to be slightly below 3 eV. Using deuterium instead of hydrogen leads to increased atomic and positive ion densities, while comparable negative ion densities are achieved. In contrast to the low work function materials, bulk samples of the refractory metals as well as carbon based materials have no enhancing effect on H-, where the latter materials furthermore show severe erosion due to the hydrogen plasma.

Simulated space environmental effects on a polyetherimide and its carbon fiber-reinforced composites

NASA Technical Reports Server (NTRS)

Kern, Kristen T.; Stancil, Phillip C.; Harries, Wynford L.; Long, Edward R., Jr.; Thibeault, Sheila A.

1993-01-01

The selection of materials for spacecraft construction requires identification of candidate materials which can perform reliably in the space environment. Understanding the effects of the space environment on the materials is an important step in the selection of candidate materials. This work examines the effects of energetic electrons, thermal cycling, electron radiation in conjunction with thermal cycling, and atomic oxygen on a thermoplastic polyetherimide and its carbon-fiber-reinforced composites. Composite materials made with non-sized fibers as well as materials made with fibers sized with an epoxy were evaluated. The mechanical and thermomechanical properties of the materials were studied and spectroscopic techniques were used to investigate the mechanisms for the observed effects. Considerations for future material development are suggested.

Working Toward a Sustainable Future

EPA Science Inventory

Population growth and economic growth have driven increased consumption of energy and materials as well as significant changes in land use, leading to erosion of natural capital. To deal with these problems in the 21st century, federal agencies must build on the existing regulato...

The Mechanical Properties of Candidate Superalloys for a Hybrid Turbine Disk

NASA Technical Reports Server (NTRS)

Gabb, Timothy P.; MacKay, Rebecca A.; Draper, Susan L.; Sudbrack, Chantal K.; Nathal, Michael V.

2013-01-01

The mechanical properties of several cast blade superalloys and one powder metallurgy disk superalloy were assessed for potential use in a dual alloy hybrid disk concept of joined dissimilar bore and web materials. Grain size was varied for each superalloy class. Tensile, creep, fatigue, and notch fatigue tests were performed at 704 to 815 degC. Typical microstructures and failure modes were determined. Preferred materials were then selected for future study as the bore and rim alloys in this hybrid disk concept. Powder metallurgy superalloy LSHR at 15 micron grain size and single crystal superalloy LDS-1101+Hf were selected for further study, and future work is recommended to develop the hybrid disk concept.

Nature-Inspired Structural Materials for Flexible Electronic Devices.

PubMed

Liu, Yaqing; He, Ke; Chen, Geng; Leow, Wan Ru; Chen, Xiaodong

2017-10-25

Exciting advancements have been made in the field of flexible electronic devices in the last two decades and will certainly lead to a revolution in peoples' lives in the future. However, because of the poor sustainability of the active materials in complex stress environments, new requirements have been adopted for the construction of flexible devices. Thus, hierarchical architectures in natural materials, which have developed various environment-adapted structures and materials through natural selection, can serve as guides to solve the limitations of materials and engineering techniques. This review covers the smart designs of structural materials inspired by natural materials and their utility in the construction of flexible devices. First, we summarize structural materials that accommodate mechanical deformations, which is the fundamental requirement for flexible devices to work properly in complex environments. Second, we discuss the functionalities of flexible devices induced by nature-inspired structural materials, including mechanical sensing, energy harvesting, physically interacting, and so on. Finally, we provide a perspective on newly developed structural materials and their potential applications in future flexible devices, as well as frontier strategies for biomimetic functions. These analyses and summaries are valuable for a systematic understanding of structural materials in electronic devices and will serve as inspirations for smart designs in flexible electronics.

Biological responses to M13 bacteriophage modified titanium surfaces in vitro.

PubMed

Sun, Yuhua; Li, Yiting; Wu, Baohua; Wang, Jianxin; Lu, Xiong; Qu, Shuxin; Weng, Jie; Feng, Bo

2017-08-01

Phage-based materials have showed great potential in tissue engineering application. However, it is unknown what inflammation response will happen to this kind of materials. This work is to explore the biological responses to M13 bacteriophage (phage) modified titanium surfaces in vitro from the aspects of their interaction with macrophages, osteoblasts and mineralization behavior. Pretreated Ti surface, Ti surfaces with noncrosslinked phage film (APP) and crosslinked phage film (APPG) were compared. Phage films could limit the macrophage adhesion and activity due to inducing adherent-cell apoptosis. The initial inflammatory activity (24h) caused by phage films was relatively high with more production of TNF-α, but in the later stage (7-10days) inflammatory response was reduced with lower TNF-α, IL-6 and higher IL-10. In addition, phage films improved osteoblast adhesion, differentiation, and hydroapatite (HA)-forming via a combination of topographical and biochemcial cues. The noncrosslinked phage film displayed the best immunomodulatory property, osteogenic activity and HA mineralization ability. This work provides better understanding of inflammatory and osteogenetic activity of phage-based materials and contributes to their future application in tissue engineering. In vivo, the bone and immune cells share a common microenvironment, and are being affected by similar cytokines, signaling molecules, transcription factors and membrane receptors. Ideal implants should cause positive biological response, including adequate and appropriate inflammatory reaction, well-balanced bone formation and absorption. Phage-based materials have showed great potential in tissue engineering application. However, at present it is unknown what inflammation response will happen to this kind of materials. A good understanding of the immune response possibly induced by phage-based materials is needed. This work studied the osteoimmunomodulation property of phage films on titanium surface, involving inflammatory response, osteogenic activity and biomineralization ability. It provides more understanding of the phage-based materials and contributes to their future application in tissue engineering. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

High-temperature behavior of advanced spacecraft TPS

NASA Technical Reports Server (NTRS)

Pallix, Joan

1994-01-01

The objective of this work has been to develop more efficient, lighter weight, and higher temperature thermal protection systems (TPS) for future reentry space vehicles. The research carried out during this funding period involved the design, analysis, testing, fabrication, and characterization of thermal protection materials to be used on future hypersonic vehicles. This work is important for the prediction of material performance at high temperature and aids in the design of thermal protection systems for a number of programs including programs such as the National Aerospace Plane (NASP), Pegasus and Pegasus/SWERVE, the Comet Rendezvous and Flyby Vehicle (CRAF), and the Mars mission entry vehicles. Research has been performed in two main areas including development and testing of thermal protection systems (TPS) and computational research. A variety of TPS materials and coatings have been developed during this funding period. Ceramic coatings were developed for flexible insulations as well as for low density ceramic insulators. Chemical vapor deposition processes were established for the fabrication of ceramic matrix composites. Experimental testing and characterization of these materials has been carried out in the NASA Ames Research Center Thermophysics Facilities and in the Ames time-of-flight mass spectrometer facility. By means of computation, we have been better able to understand the flow structure and properties of the TPS components and to estimate the aerothermal heating, stress, ablation rate, thermal response, and shape change on the surfaces of TPS. In addition, work for the computational surface thermochemistry project has included modification of existing computer codes and creating new codes to model material response and shape change on atmospheric entry vehicles in a variety of environments (e.g., earth and Mars atmospheres).

High-temperature behavior of advanced spacecraft TPS

NASA Astrophysics Data System (ADS)

Pallix, Joan

1994-05-01

The objective of this work has been to develop more efficient, lighter weight, and higher temperature thermal protection systems (TPS) for future reentry space vehicles. The research carried out during this funding period involved the design, analysis, testing, fabrication, and characterization of thermal protection materials to be used on future hypersonic vehicles. This work is important for the prediction of material performance at high temperature and aids in the design of thermal protection systems for a number of programs including programs such as the National Aerospace Plane (NASP), Pegasus and Pegasus/SWERVE, the Comet Rendezvous and Flyby Vehicle (CRAF), and the Mars mission entry vehicles. Research has been performed in two main areas including development and testing of thermal protection systems (TPS) and computational research. A variety of TPS materials and coatings have been developed during this funding period. Ceramic coatings were developed for flexible insulations as well as for low density ceramic insulators. Chemical vapor deposition processes were established for the fabrication of ceramic matrix composites. Experimental testing and characterization of these materials has been carried out in the NASA Ames Research Center Thermophysics Facilities and in the Ames time-of-flight mass spectrometer facility. By means of computation, we have been better able to understand the flow structure and properties of the TPS components and to estimate the aerothermal heating, stress, ablation rate, thermal response, and shape change on the surfaces of TPS. In addition, work for the computational surface thermochemistry project has included modification of existing computer codes and creating new codes to model material response and shape change on atmospheric entry vehicles in a variety of environments (e.g., earth and Mars atmospheres).

Application and utilization of a space chamber for the drying and decontamination of books, documents and other materials

NASA Technical Reports Server (NTRS)

Koesterer, M. G.; Geating, J. A.

1975-01-01

Truckloads of materials such as rare books, papers, engineering drawings, blue prints, art work, leather objects such as shoes, and clothing were successfully dried, decontaminated and impregnated against future infestation by microorganisms in a large 12 x 24 foot vacuum chamber designed originally for testing unmanned spacecraft. The process is unique in that it allows either frozen or wet material, soaked by some castastrophic event to be dried and sterilized in the same chamber with a minimum of handling and transportation.

(Project 14-6770) An Investigation to Establish Multiphysical Property Dataset of Nuclear Materials Based on in-situ Observations and Measurements

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

Tomar, Vikas; Haque, Aman; Hattar, Khalid

In-core nuclear materials including fuel pins and cladding materials fail due to issues including corrosion, mechanical wear, and pellet cladding interaction. In most such scenario microstructure dependent and corrosioninduced chemistry dependent property changes significantly affect performance of cladding, pellet, and housing. Emphasis of this work was on replace conventional pellet-cladding material models with a new straingradient viscoplasticity model that is informed by transmission electron microscopy (TEM) based measurements and by nanomechanical Raman spectroscopy (NMRS) based measurements. The TEM measurements are quantitative in nature and therefore reveal stress-strain relations with simultaneous insights into mechanisms of deformation at nanoscale. The NMRS measurementsmore » reveal the similar information at mesoscale along with additional information on relating local microstructural stresses with applied stresses. The resulting information is used to fit constants in the strain gradient viscoplasticity model as well as to validate one. During TEM measurements, a micro-electro-mechanical system based setup was developed with mechanical actuation, sensing, heating, and electrical loading. Contrary to post-mortem analysis or qualitative visualization, this setup combines direct visualization of the mechanisms behind deformation with measurement of stress, strain, thermal and electrical properties. The unique research philosophy of visualizing the microstructure at high resolution while measuring the properties led to fundamental understanding in grain size and temperature effects on measured mechanical properties such as fracture toughness. A key contribution is the role of mechanical loading boundary conditions to deconvolute the insitu TEM based nanoscale and NMRS based mesoscale data to bulk behavior. First the literature based pellet cladding mechanical interaction model based on the work of Retel’s and Williamson’s in literature work to predict tempurature and stress distribution in cladding and pellet at normal operating condition was analyzed. Later the data was fitted to find constants for a viscoplastic strain gradient model. The developed model still needs to be refined and calibrated using various experimental results. That remains the focus of future work. Overall, a major thrust of the work was therefore on active control of the microstructure (grain size, defect density and types) exploiting the multi-physics coupling in materials. In particular, using experiments the synergy of current density, mechanical stress and temperature were studied to annihilate defects and recrystallize grains. The developed model is being examined for implementation in BISON. Multiple invited talks, international journal publications, and conference publications were performed by students supported on this work. Another output is support multiple PhD and masters thesis students who will be an important asset for future basic nuclear research. Future Work Recommendations: A nuclear reactor operates under significant variations of thermal loads due to energy cycling and mechanical loads due to constraint effects. Significant thermal and chemical diffusion takes place at the pallet-cladding level. While the proposed work established new experimental approach and new dataset for Zircaloy-4, the irradiation level was in the range of 1-2 dpa. Samples with higher dpa need to be examined. Therefore, a continual of support of the performed work is essential. Currently, these are the only experiments that can measure the produced data. The work also needs to be extended to different fuel types and cladding types such as SiC and FeCrAl based claddings. A combination of datasets for these materials can then be used to analyze accurately predict behavior of critical pellet cladding systems in accident scenario with high heat flux and high thermal loads. This is a BIG unknown as if now.« less

Carrier statistics and quantum capacitance effects on mobility extraction in two-dimensional crystal semiconductor field-effect transistors

NASA Astrophysics Data System (ADS)

Ma, Nan; Jena, Debdeep

2015-03-01

In this work, the consequence of the high band-edge density of states on the carrier statistics and quantum capacitance in transition metal dichalcogenide two-dimensional semiconductor devices is explored. The study questions the validity of commonly used expressions for extracting carrier densities and field-effect mobilities from the transfer characteristics of transistors with such channel materials. By comparison to experimental data, a new method for the accurate extraction of carrier densities and mobilities is outlined. The work thus highlights a fundamental difference between these materials and traditional semiconductors that must be considered in future experimental measurements.

Weather Satellite Pictures and How to Obtain Them.

ERIC Educational Resources Information Center

Petit, Noel J.; Johnson, Philip

1982-01-01

An introduction to satellite meteorology is presented to promote use of live weather satellite photographs in the classroom. Topics addressed include weather satellites, how they work, earth emissions, satellite photography, satellite image analysis, obtaining satellite pictures, and future considerations. Includes sources for materials to…

INVESTIGATIONS IN PANAMA DURING THE SUMMER OF 1930.

PubMed

Faust, E C

1931-01-09

The material obtained from these investigations has indicated to the writer that the area studied offers extremely valuable opportunities for helminthological and protozoological work. The data obtained will serve as the basis for several important papers which will be published in the near future.

Castles Made of Sand: Building Sustainable Digitized Collections Using XML.

ERIC Educational Resources Information Center

Ragon, Bart

2003-01-01

Describes work at the University of Virginia library to digitize special collections. Discusses the use of XML (Extensible Markup Language); providing access to original source materials; DTD (Document Type Definition); TEI (Text Encoding Initiative); metadata; XSL (Extensible Style Language); and future possibilities. (LRW)

Cryogenic Selective Surfaces: A Phase 2 NIAC Project: Mid-Term Continuation Review

NASA Technical Reports Server (NTRS)

Youngquist, Robert; Nurge, Mark; Gibson, Tracy; Johnson, Wesley

2017-01-01

The NASA Innovative Advanced Concepts (NIAC) program has been funding work at KSC (Kennedy Space Center) on a new coating that should allow cryogenic commodities to be stored in deep space. Recently a mid-term review of this work was given. I am requesting that this presentation be cleared for release so that the material can be presented publicly at an upcoming FISO (Future in Space) telecom.

Levitating Trains and Kamikaze Genes: Technological Literacy for the Future

NASA Astrophysics Data System (ADS)

Brennan, Richard P.

1994-08-01

A lively survey of the horizons of modern technology. Provides easy-to-read summaries of the state of the art in space science, biotechnology, computer science, exotic energy sources and materials engineering as well as life-enhancing medical advancements and environmental, transportation and defense/weapons technologies. Each chapter explains how a current or future technology works and provides an understanding of the underlying scientific concepts. Includes an extensive self-test to review your knowledge.

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.

Plasma-wall interaction data needs critical to a Burning Core Experiment (BCX)

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

Not Available

1985-11-01

The Division of Development and Technology has sponsored a four day US-Japan workshop ''Plasma-Wall Interaction Data Needs Critical to a Burning Core Experiment (BCX)'', held at Sandia National Laboratories, Livermore, California on June 24 to 27, 1985. The workshop, which brought together fifty scientists and engineers from the United States, Japan, Germany, and Canada, considered the plasma-material interaction and high heat flux (PMI/HHF) issues for the next generation of magnetic fusion energy devices, the Burning Core Experiment (BCX). Materials options were ranked, and a strategy for future PMI/HHF research was formulated. The foundation for international collaboration and coordination of thismore » research was also established. This volume contains the last three of the five technical sessions. The first of the three is on plasma materials interaction issues, the second is on research facilities and the third is from smaller working group meetings on graphite, beryllium, advanced materials and future collaborations.« less

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

Clayton, C.; Gueretta, J.; Tack, J.

The Manhattan Engineer District (MED) and U.S. Atomic Energy Commission (AEC) contracted for support work through private and academic parties through the early 1960's. The work often involved radioactive materials. Residual radioactive contamination was left at some of more than 600 potentially contaminated (candidate) sites, and worker health and safety concerns remain from the site operations and subsequent remediation activities. The U.S. Department of Energy (DOE) initiated a program to identify and protect records of MED/AEC activities and of remediation work conducted under the Formerly Utilized Sites Remedial Action Program (FUSRAP) to aid in resolving questions about site conditions, liability,more » and worker health and safety and to ensure ongoing protectiveness of human health and the environment. This paper discusses DOE activities undertaken to locate records collections, confirm retention schedules and access requirements, and document information about the collections for use by future stewards. In conclusion: DOE-LM recognizes that records and information management is a critical component of effective LTS and M. Records are needed to answer questions about site conditions and demonstrate to the public in the future that the sites are safe. DOE-LM is working to satisfy present needs and anticipate future uses for FUSRAP records, and compile a collection of site and program information from which future stewards can readily locate and retrieve needed information. (authors)« less

High Speed Research Program Structural Acoustics Multi-Year Summary Report

NASA Technical Reports Server (NTRS)

Beier, Theodor H.; Bhat, Waman V.; Rizzi, Stephen A.; Silcox, Richard J.; Simpson, Myles A.

2005-01-01

This report summarizes the work conducted by the Structural Acoustics Integrated Technology Development (ITD) Team under NASA's High Speed Research (HSR) Phase II program from 1993 to 1999. It is intended to serve as a reference for future researchers by documenting the results of the interior noise and sonic fatigue technology development activities conducted during this period. For interior noise, these activities included excitation modeling, structural acoustic response modeling, development of passive treatments and active controls, and prediction of interior noise. For sonic fatigue, these activities included loads prediction, materials characterization, sonic fatigue code development, development of response reduction techniques, and generation of sonic fatigue design requirements. Also included are lessons learned and recommendations for future work.

Student Housing Cost Study.

ERIC Educational Resources Information Center

California Univ., Berkeley. Univ. Residential Building System.

Target costs for the University Residential Building System (URBS) Project of the University of California are presented. Findings depict the effectiveness of building design and material applications and should be useful in guiding future student housing design work, whether the design utilizes the URBS system or not. Ten recently constructed…

Time domain simulation of novel photovoltaic materials

NASA Astrophysics Data System (ADS)

Chung, Haejun

Thin-film silicon-based solar cells have operated far from the Shockley- Queisser limit in all experiments to date. Novel light-trapping structures, however, may help address this limitation. Finite-difference time domain simulation methods offer the potential to accurately determine the light-trapping potential of arbitrary dielectric structures, but suffer from materials modeling problems. In this thesis, existing dispersion models for novel photovoltaic materials will be reviewed, and a novel dispersion model, known as the quadratic complex rational function (QCRF), will be proposed. It has the advantage of accurately fitting experimental semiconductor dielectric values over a wide bandwidth in a numerically stable fashion. Applying the proposed dispersion model, a statistically correlated surface texturing method will be suggested, and light absorption rates of it will be explained. In future work, these designs will be combined with other structures and optimized to help guide future experiments.

Frontiers in poly(ionic liquid)s: syntheses and applications.

PubMed

Qian, Wenjing; Texter, John; Yan, Feng

2017-02-20

We review recent works on the synthesis and application of poly(ionic liquid)s (PILs). Novel chemical structures, different synthetic strategies and controllable morphologies are introduced as a supplement to PIL systems already reported. The primary properties determining applications, such as ionic conductivity, aqueous solubility, thermodynamic stability and electrochemical/chemical durability, are discussed. Furthermore, the near-term applications of PILs in multiple fields, such as their use in electrochemical energy materials, stimuli-responsive materials, carbon materials, and antimicrobial materials, in catalysis, in sensors, in absorption and in separation materials, as well as several special-interest applications, are described in detail. We also discuss the limitations of PIL applications, efforts to improve PIL physics, and likely future developments.

Indigenous lunar construction materials

NASA Technical Reports Server (NTRS)

Rogers, Wayne; Sture, Stein

1991-01-01

The objectives are the following: to investigate the feasibility of the use of local lunar resources for construction of a lunar base structure; to develop a material processing method and integrate the method with design and construction of a pressurized habitation structure; to estimate specifications of the support equipment necessary for material processing and construction; and to provide parameters for systems models of lunar base constructions, supply, and operations. The topics are presented in viewgraph form and include the following: comparison of various lunar structures; guidelines for material processing methods; cast lunar regolith; examples of cast basalt components; cast regolith process; processing equipment; mechanical properties of cast basalt; material properties and structural design; and future work.

Guia Para El Mejoramiento de la Produccion de Materiales Para la Educacion Formal y No Formal. Guias Metodologicas No. 6. (Guide for the Improvement of Production of Educational Materials for Formal and Non-formal Education. Methodology Guide No. 6). Revised Proceedings from the Regional Workshop on Improvement of the Production of Educational Materials on Teaching Population Education: Primary and Secondary Level (Santiago, Chile, May 27-June 5, 1987).

ERIC Educational Resources Information Center

Calvo, Gilbert

Various educators from Latin and Central America and the Caribbean met to design and produce materials for teaching family life, human sexuality, community life, and environmental studies. They concluded that the materials should meet community standards; help prepare for future change; develop working models for designing effective teaching…

International Space Station (ISS)

NASA Image and Video Library

2001-08-18

Astronaut Patrick G. Forrester works with the the Materials International Space Station Experiment (MISSE) during extravehicular activity (EVA). MISSE would expose 750 material samples for about 18 months and collect information on how different materials weather the space environment The objective of MISSE is to develop early, low-cost, non-intrusive opportunities to conduct critical space exposure tests of space materials and components plarned for use on future spacecraft. The experiment was the first externally mounted experiment conducted on the International Space Station (ISS) and was installed on the outside of the ISS Quest Airlock. MISSE was launched on August 10, 2001 aboard the Space Shuttle Orbiter Discovery.

Molecular Nanotechnology and Designs of Future

NASA Technical Reports Server (NTRS)

Srivastava, Deepak; Chancellor, Marisa K. (Technical Monitor)

1997-01-01

Reviewing the status of current approaches and future projections, as already published in the scientific journals and books, the talk will summarize the direction in which computational and experimental molecular nanotechnologies are progressing. Examples of nanotechnological approach to the concepts of design and simulation of atomically precise materials in a variety of interdisciplinary areas will be presented. The concepts of hypothetical molecular machines and assemblers as explained in Drexler's and Merckle's already published work and Han et. al's WWW distributed molecular gears will be explained.

Progress in revising and supplementing fundamental optical ISO standards

NASA Astrophysics Data System (ADS)

Schuhmann, Rainer

2017-11-01

This overview reflects the ISO working group activities of ISO/TC 172 Subcommittee 1 during the last years which have resulted in revisions and new ISO standards for optical components. For ISO 10110, ISO 14999 and other standards new surface forms and metrology techniques have been considered, standards about material characteristics have been consolidated, and optical drawings have been updated. Selected examples of new improvements and future work items are given.

Class of 1994, Annual Report: NH Technical Colleges and Institute and NH Police Standards and Training.

ERIC Educational Resources Information Center

New Hampshire State Dept. of Postsecondary Technical Education, Concord.

This 1994 annual report for the New Hampshire Technical Colleges and Institute System (NHTC&IS) includes information on enrollments, outcomes, job placement, average salaries, transfer institutions, work force training, the Police Academy, finances, future directions, and governance. Introductory material highlights the following…

Envisioning the Future: Working toward Sustainability in Fine Art Education

ERIC Educational Resources Information Center

Clarke, Angela; Hulbert, Shane

2016-01-01

Fine art education provides students with opportunities to acquire knowledge and skills to respond creatively to their experience of society and culture. Fostering creative ways of knowing, thinking and doing requires studio learning conditions that promote the exploration of embodied perceptions, material sensibilities and conceptual ideas that…

Collaborative engagement experiment

NASA Astrophysics Data System (ADS)

Mullens, Katherine; Troyer, Bradley; Wade, Robert; Skibba, Brian; Dunn, Michael

2006-05-01

Unmanned ground and air systems operating in collaboration have the potential to provide future Joint Forces a significant capability for operations in complex terrain. Collaborative Engagement Experiment (CEE) is a consolidation of separate Air Force, Army and Navy collaborative efforts within the Joint Robotics Program (JRP) to provide a picture of the future of unmanned warfare. The Air Force Research Laboratory (AFRL), Material and Manufacturing Directorate, Aerospace Expeditionary Force Division, Force Protection Branch (AFRL/MLQF), The Army Aviation and Missile Research, Development and Engineering Center (AMRDEC) Joint Technology Center (JTC)/Systems Integration Laboratory (SIL), and the Space and Naval Warfare Systems Center - San Diego (SSC San Diego) are conducting technical research and proof of principle experiments for an envisioned operational concept for extended range, three dimensional, collaborative operations between unmanned systems, with enhanced situational awareness for lethal operations in complex terrain. This paper describes the work by these organizations to date and outlines some of the plans for future work.

High-Temperature Piezoelectric Sensing

PubMed Central

Jiang, Xiaoning; Kim, Kyungrim; Zhang, Shujun; Johnson, Joseph; Salazar, Giovanni

2014-01-01

Piezoelectric sensing is of increasing interest for high-temperature applications in aerospace, automotive, power plants and material processing due to its low cost, compact sensor size and simple signal conditioning, in comparison with other high-temperature sensing techniques. This paper presented an overview of high-temperature piezoelectric sensing techniques. Firstly, different types of high-temperature piezoelectric single crystals, electrode materials, and their pros and cons are discussed. Secondly, recent work on high-temperature piezoelectric sensors including accelerometer, surface acoustic wave sensor, ultrasound transducer, acoustic emission sensor, gas sensor, and pressure sensor for temperatures up to 1,250 °C were reviewed. Finally, discussions of existing challenges and future work for high-temperature piezoelectric sensing are presented. PMID:24361928

Acoustic invisibility cloaks of arbitrary shapes for complex background media

NASA Astrophysics Data System (ADS)

Zhu, Jian; Chen, Tianning; Liang, Qingxuan; Wang, Xiaopeng; Xiong, Jie; Jiang, Ping

2016-04-01

We report on the theoretical investigation of the acoustic cloaks working in complex background media in this paper. The constitutive parameters of arbitrary-shape cloaks are derived based on the transformation acoustic theory and coordinate transformation technique. The detailed analysis of boundaries conditions and potential applications of the cloaks are also presented in our work. To overcome the difficulty of achieving the materials with ideal parameters in nature, concentric alternating layered isotropic materials is adopted to approximate the required properties of the cloak. Theoretical design and excellent invisibility are demonstrated by numerical simulations. The inhomogeneous medium and arbitrary-shape acoustic cloaks grow closer to real application and may be a new hot spot in future.

Introduction to the IEEE International Symposium on Applications of Ferroelectrics and International Symposium on Piezoresponse Force Microscopy and Nanoscale Phenomena in Polar Materials.

PubMed

Ye, Zuo-Guang; Tan, Xiaoli; Bokov, Alexei A

2012-09-01

The 20th IEEE International Symposium on Applications of Ferroelectrics (ISAF) was held on July 24-27, 2011, in Vancouver, British Columbia, Canada, jointly with the International Symposium on Piezoresponse Force Microscopy and Nanoscale Phenomena in Polar Materials (PFM). Over a period of four days, approximately 400 scientists, engineers, and students from around the world presented their work and discussed the latest developments in the field of ferroelectrics, related materials, and their applications. It is particularly encouraging to see that a large number of students (115) were attracted to the joint conference and presented high-quality research works. This trend is not only important to this conference series, but more importantly, it is vital to the future of the ferroelectrics field.

Third Conference on Fibrous Composites in Flight Vehicle Design, part 1

NASA Technical Reports Server (NTRS)

1976-01-01

The use of fibrous composite materials in the design of aircraft and space vehicle structures and their impact on future vehicle systems are discussed. The topics covered include: flight test work on composite components, design concepts and hardware, specialized applications, operational experience, certification and design criteria. Contributions to the design technology base include data concerning material properties, design procedures, environmental exposure effects, manufacturing procedures, and flight service reliability. By including composites as baseline design materials, significant payoffs are expected in terms of reduced structural weight fractions, longer structural life, reduced fuel consumption, reduced structural complexity, and reduced manufacturing cost.

Recent progress in research on tungsten materials for nuclear fusion applications in Europe

NASA Astrophysics Data System (ADS)

Rieth, M.; Dudarev, S. L.; Gonzalez de Vicente, S. M.; Aktaa, J.; Ahlgren, T.; Antusch, S.; Armstrong, D. E. J.; Balden, M.; Baluc, N.; Barthe, M.-F.; Basuki, W. W.; Battabyal, M.; Becquart, C. S.; Blagoeva, D.; Boldyryeva, H.; Brinkmann, J.; Celino, M.; Ciupinski, L.; Correia, J. B.; De Backer, A.; Domain, C.; Gaganidze, E.; García-Rosales, C.; Gibson, J.; Gilbert, M. R.; Giusepponi, S.; Gludovatz, B.; Greuner, H.; Heinola, K.; Höschen, T.; Hoffmann, A.; Holstein, N.; Koch, F.; Krauss, W.; Li, H.; Lindig, S.; Linke, J.; Linsmeier, Ch.; López-Ruiz, P.; Maier, H.; Matejicek, J.; Mishra, T. P.; Muhammed, M.; Muñoz, A.; Muzyk, M.; Nordlund, K.; Nguyen-Manh, D.; Opschoor, J.; Ordás, N.; Palacios, T.; Pintsuk, G.; Pippan, R.; Reiser, J.; Riesch, J.; Roberts, S. G.; Romaner, L.; Rosiński, M.; Sanchez, M.; Schulmeyer, W.; Traxler, H.; Ureña, A.; van der Laan, J. G.; Veleva, L.; Wahlberg, S.; Walter, M.; Weber, T.; Weitkamp, T.; Wurster, S.; Yar, M. A.; You, J. H.; Zivelonghi, A.

2013-01-01

The current magnetic confinement nuclear fusion power reactor concepts going beyond ITER are based on assumptions about the availability of materials with extreme mechanical, heat, and neutron load capacity. In Europe, the development of such structural and armour materials together with the necessary production, machining, and fabrication technologies is pursued within the EFDA long-term fusion materials programme. This paper reviews the progress of work within the programme in the area of tungsten and tungsten alloys. Results, conclusions, and future projections are summarized for each of the programme's main subtopics, which are: (1) fabrication, (2) structural W materials, (3) W armour materials, and (4) materials science and modelling. It gives a detailed overview of the latest results on materials research, fabrication processes, joining options, high heat flux testing, plasticity studies, modelling, and validation experiments.

Excess Weapons Plutonium Immobilization in Russia

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

Jardine, L.; Borisov, G.B.

2000-04-15

The joint goal of the Russian work is to establish a full-scale plutonium immobilization facility at a Russian industrial site by 2005. To achieve this requires that the necessary engineering and technical basis be developed in these Russian projects and the needed Russian approvals be obtained to conduct industrial-scale immobilization of plutonium-containing materials at a Russian industrial site by the 2005 date. This meeting and future work will provide the basis for joint decisions. Supporting R&D projects are being carried out at Russian Institutes that directly support the technical needs of Russian industrial sites to immobilize plutonium-containing materials. Special R&Dmore » on plutonium materials is also being carried out to support excess weapons disposition in Russia and the US, including nonproliferation studies of plutonium recovery from immobilization forms and accelerated radiation damage studies of the US-specified plutonium ceramic for immobilizing plutonium. This intriguing and extraordinary cooperation on certain aspects of the weapons plutonium problem is now progressing well and much work with plutonium has been completed in the past two years. Because much excellent and unique scientific and engineering technical work has now been completed in Russia in many aspects of plutonium immobilization, this meeting in St. Petersburg was both timely and necessary to summarize, review, and discuss these efforts among those who performed the actual work. The results of this meeting will help the US and Russia jointly define the future direction of the Russian plutonium immobilization program, and make it an even stronger and more integrated Russian program. The two objectives for the meeting were to: (1) Bring together the Russian organizations, experts, and managers performing the work into one place for four days to review and discuss their work with each other; and (2) Publish a meeting summary and a proceedings to compile reports of all the excellent Russian plutonium immobilization contract work. This proceedings document presents the wide extent of Russian immobilization activities, provides a reference for their work, and makes it available to others.« less

Anaerobic digestion of organic solid poultry slaughterhouse waste--a review.

PubMed

Salminen, E; Rintala, J

2002-05-01

This work reviews the potential of anaerobic digestion for material recovery and energy production from poultry slaughtering by-products and wastes. First, we describe and quantify organic solid by-products and wastes produced in poultry farming and poultry slaughterhouses and discuss their recovery and disposal options. Then we review certain fundamental aspects of anaerobic digestion considered important for the digestion of solid slaughterhouse wastes. Finally, we present an overview of the future potential and current experience of the anaerobic digestion treatment of these materials.

Imprinted magnetic graphene oxide for the mini-solid phase extraction of Eu (III) from coal mine area

NASA Astrophysics Data System (ADS)

Patra, Santanu; Roy, Ekta; Madhuri, Rashmi; Sharma, Prashant K.

2017-05-01

The present work represents the preparation of imprinted magnetic reduced graphene oxide and applied it for the selective removal of Eu (III) from local coal mines area. A simple solid phase extraction method was used for this purpose. The material shows a very high adsorption as well as removal efficiency towards Eu (III), which suggest that the material have potential to be used in future for their real time applications in removal of Eu (III) from complex matrices.

Believing Your Eyes: Strengthening the Reliability of Tags and Seals

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

Brim, Cornelia P.; Denlinger, Laura S.

2013-07-01

NNSA’s Office of Nonproliferation and International Security (NIS) is working together with scientific experts at the DOE national laboratories to develop the tools needed to safeguard and secure nuclear material from diversion, theft, and sabotage--tasks critical to support future arms control treaties that may involve the new challenge of monitoring nuclear weapons dismantlement. Use of optically stimulated luminescent material is one method to enhance the security and robustness of existing tamper indicating devices such as tags and seals.

Analytical Chemistry at the Interface Between Materials Science and Biology

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

O'Brien, Janese C.

2000-09-21

Likedlessentid sciences, anal~cd chetis~continues toreinvent itself. Moving beyond its traditional roles of identification and quantification, analytical chemistry is now expanding its frontiers into areas previously reserved to other disciplines. This work describes several research efforts that lie at the new interfaces between analytical chemistry and two of these disciplines, namely materials science and biology. In the materials science realm, the search for new materials that may have useful or unique chromatographic properties motivated the synthesis and characterization of electrically conductive sol-gels. In the biology realm, the search for new surface fabrication schemes that would permit or even improve the detectionmore » of specific biological reactions motivated the design of miniaturized biological arrays. Collectively, this work represents some of analytical chemistry’s newest forays into these disciplines. The introduction section to this dissertation provides a literature review on several of the key aspects of this work. In advance of the materials science discussion, a brief introduction into electrochemically-modulated liquid chromatography (EMLC) and sol-gel chemistry is provided. In advance of the biological discussions, brief overviews of scanning force microscopy (SFM) and the oxidative chemistry used to construct our biological arrays are provided. This section is followed by four chapters, each of which is presented as a separate manuscript, and focuses on work that describes some of our cross-disciplinary efforts within materials science and biology. This dissertation concludes with a general summary and future prospectus.« less

Design, crystal growth, and physical properties of low-temperature thermoelectric materials

NASA Astrophysics Data System (ADS)

Fuccillo, Michael K.

Thermoelectric materials serve as the foundation for two important modern technologies, namely 1) solid-state cooling, which enables small-area refrigeration without vibrations or moving parts, and 2) thermoelectric power generation, which has important implications for waste heat recovery and improved sources of alternative energy. Although the overall field of thermoelectrics research has been active for decades, and several consumer and industrial products have already been commercialized, the design and synthesis of new thermoelectrics that outperform long-standing state of the art materials has proven extremely challenging. This is particularly true for low-temperature refrigeration applications, which is the focus of this work; however, scientific advances in this area generally support power generation as well. In order to achieve more efficient materials for virtually all thermoelectric applications, improved materials design principles must be developed and synthetic procedures must be better understood. We aim to contribute to these goals by studying two classes of materials, namely 1) the tetradymites Bi2TeSe 2 and Bi2Te2Se, which are close relatives of state of the art thermoelectric cooling materials, and 2) Kondo insulating (-like) FeSb2 and FeSi, which possess anomalously enhanced low-temperature thermoelectric properties that arise from exotic electronic and magnetic properties. The organization of this dissertation is as follows: Chapter 1 is a brief perspective on solid-state chemistry. Chapter 2 presents experimental methods for synthesizing and characterizing thermoelectric materials. In Chapter 3, two original research projects are discussed: first, work on the tetradymite Bi2TeSe2 doped with Sb to achieve an n- to p-type transition, and second, the tetradymite Bi2Te2Se with chemical defects through two different methods. Chapter 4 gives the magnetic and transport properties of FeSb 2--RuSb2 alloys, a family of compounds exemplifying what we consider to be the next generation of thermoelectric materials for low-temperature cooling due to their anomalously enhanced low-temperature thermoelectric properties, along with an outlook for seeking additional materials with similarly enhanced properties. Lastly, in Chapter 5, a brief outlook on the future of thermoelectrics is discussed, along with our current and future work on FeSi-RuSi alloys.

Electrostatics of Granular Materials

NASA Technical Reports Server (NTRS)

Marshall, John

2004-01-01

The purpose of the research was to continue developing an understanding of electrostatic phenomena in preparation for any future flight opportunities of the EGM experiment, originally slated for a 2004 Space Station deployment. Work would be based on theoretical assessments, ground-based lab experiments, and reduced-gravity experiments. The ability to examine dipoles in the lab proved to be elusive, and thus, effort was concentrated on monopoles -how materials become charged, the fate of the charge, the role of material type, and so forth. Several significant milestones were achieved in this regard. In regard of the dipoles, experiments were designed in collaboration with the University of Chicago school district who had access to reduced gravity on the KC-135 aircraft. Two experiments were slated to fly last year but were cancelled after the Columbia accident. One of the experiments has been given a second life and will fly sometime in 2005 if the Shuttle flights resume. There remains active interest in the question of electrostatic dipoles within the educational community, and experiments using magnetic dipoles as a substitute are to be examined. The KC-135 experiments will also examine dispersion methods for particles as a verification of possible future techniques in microgravity. Both laboratory and theoretical work established a number of breakthroughs in our understanding of electrostatic phenomena. These breakthroughs are listed in this paper.

Fishing the Fermi sea

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

Canfield, P.

2008-03-01

Sophocles had it right, the Rolling Stones made a friendly amendment and Linus Pauling detailed the conceptual mechanism for finding novel materials that will define and revolutionize the future. Within the field of solid-state physics, the discovery of remarkable phases and transitions is often tightly coupled to the design, discovery and growth of novel materials. The past several decades of work in the field of correlated electron physics - that is, the study of materials in which the interactions are sufficiently strong that conventional single-electron theories don't apply - can be described by a list of materials that have definedmore » new extremes, be it extremes of temperature, field, pressure, complexity or, even better, simplicity.« less

Intermetallics for Thermal Protection Systems

NASA Astrophysics Data System (ADS)

Marcos, J.

2009-01-01

Future Reusable Launch Vehicles (RLV's) will require improved Thermal Protection Systems (TPS) to achieve the ambitious goal of reducing the cost of delivering a payload to orbit by, at least, an order of magnitude. In this context, metallic materials are good candidates for their use in TPS and hot structures. Up to date, only two major type of materials have been considered and developed in Europe for such type of applications: Oxide Dispersion Strengthened (ODS) and intermetallics (ϒ-TiAl). INASMET, during last years, has been working with the orthorhombic titanium aluminides, whose specific properties are comparable, to those of ODS and ϒ-TiAl materials. The EXPERT mission represents a unique opportunity to test under re-entry conditions this material.

A comprehensive program to develop correlations for physical properties of kraft black liquor. Final report

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

Fricke, A.L.; Zaman, A.A.; Stoy, M.O.

A wide variety of experimental techniques have been used in this work, and many of these have been developed completely or improved significantly in the course of the research done during this program. Therefore, it is appropriate to describe these techniques in detail as a reference for future workers so that the techniques can be used in future work with little additional effort or so that the results reported from this program can be compared better with future results from other work. In many cases, the techniques described are for specific analytical instruments. It is recognized that these may bemore » superseded by future developments and improvements in instrumentation if a complete description of techniques used successfully in the past on other instrumentation is available. The total pulping and liquor preparation research work performed included chip and white liquor preparation, digestion, pulp washing, liquor and wash recovery, liquor sampling, weak liquor concentration in two steps to about 45--50% solids with an intermediate soap skimming at about 140F and 27--30% solids, determination of pulp yield and Kappa number, determination of total liquor solids, and a check on the total material balance for pulping. All other research was performed either on a sample of the weak black liquor (the combined black liquor and washes from the digester) or on the skimmed liquor that had been concentrated.« less

Collegiate Sampler: Undergrads Talk About Values, Ambitions, Business.

ERIC Educational Resources Information Center

Emhart Corp., Hartford, CT.

Information on college students' attitudes toward work, material possessions, national issues, the future, and other topics were surveyed in 1980. A sample of undergraduate students who subscribed to "Business Today" magazine were assessed using a four-page mail questionnaire; of the 2,000 questionnaires sent out, 937 were completed. It was found…

ACTFL Workshop Proceedings: Black Literature of French Expression.

ERIC Educational Resources Information Center

Geno, Thomas H., Ed.; Bostick, Herman F., Ed.

This compilation of working papers is part 1 of the proceedings of the ACTFL 1972 preconference workshop on black francophone literature. Part 2, to be completed in the future, will be a bibliography containing primary and secondary sources, textbooks, articles, a glossary of African terms, and resource materials useful in language classrooms. The…

Mars landing site catalog

NASA Technical Reports Server (NTRS)

Greeley, Ronald (Editor)

1990-01-01

The catalog was compiled from material provided by the planetary community for areas on Mars that are of potential interest for future exploration. The catalog has been edited for consistency insofar as practical; however, the proposed scientific objectives and characteristics have not been reviewed. This is a working catalog that is being revised, updated, and expanded continually.

Adjoint-based optimization of mechanical performance in polycrystalline materials and structures through texture control

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

Gu, Grace; Brown, Judith Alice; Bishop, Joseph E.

The texture of a polycrystalline material refers to the preferred orientation of the grains within the material. In metallic materials, texture can significantly affect the mechanical properties such as elastic moduli, yield stress, strain hardening, and fracture toughness. Recent advances in additive manufacturing of metallic materials offer the possibility in the not too distant future of controlling the spatial variation of texture. In this work, we investigate the advantages, in terms of mechanical performance, of allowing the texture to vary spatially. We use an adjoint-based gradient optimization algorithm within a finite element solver (COMSOL) to optimize several engineering quantities ofmore » interest in a simple structure (hole in a plate) and loading (uniaxial tension) condition. As a first step to general texture optimization, we consider the idealized case of a pure fiber texture in which the homogenized properties are transversely isotropic. In this special case, the only spatially varying design variables are the three Euler angles that prescribe the orientation of the homogenized material at each point within the structure. This work paves a new way to design metallic materials for tunable mechanical properties at the microstructure level.« less

KSC-2013-3908

NASA Image and Video Library

2013-11-07

CAPE CANAVERAL, Fla. -- Dust particles scatter during an experiment for the Electrodynamic Dust Shield for Dust Mitigation project in the Electrostatics and Surface Physics Laboratory in the SwampWorks at NASA's Kennedy Space Center in Florida. The fabricated material is designed to mimic the dust on the lunar surface. The technology works by creating an electric field that propagates out like the ripples on a pond. This could prevent dust accumulation on spacesuits, thermal radiators, solar panels, optical instruments and view ports for future lunar and Mars exploration activities. CAPE CANAVERAL, Fla. -- Preparations are underway to conduct a dust particle experiment for the Electrodynamic Dust Shield for Dust Mitigation project in the Electrostatics and Surface Physics Laboratory in the SwampWorks at NASA's Kennedy Space Center in Florida. The technology works by creating an electric field that propagates out like the ripples on a pond. This could prevent dust accumulation on spacesuits, thermal radiators, solar panels, optical instruments and view ports for future lunar and Mars exploration activities.

KSC-2013-3907

NASA Image and Video Library

2013-11-07

CAPE CANAVERAL, Fla. -- Dust particles are readied for an experiment for the Electrodynamic Dust Shield for Dust Mitigation project in the Electrostatics and Surface Physics Laboratory in the SwampWorks at NASA's Kennedy Space Center in Florida. The fabricated material is designed to mimic the dust on the lunar surface. The technology works by creating an electric field that propagates out like the ripples on a pond. This could prevent dust accumulation on spacesuits, thermal radiators, solar panels, optical instruments and view ports for future lunar and Mars exploration activities. CAPE CANAVERAL, Fla. -- Preparations are underway to conduct a dust particle experiment for the Electrodynamic Dust Shield for Dust Mitigation project in the Electrostatics and Surface Physics Laboratory in the SwampWorks at NASA's Kennedy Space Center in Florida. The technology works by creating an electric field that propagates out like the ripples on a pond. This could prevent dust accumulation on spacesuits, thermal radiators, solar panels, optical instruments and view ports for future lunar and Mars exploration activities.

A Review of the Experimental and Modeling Development of a Water Phase Change Heat Exchanger for Future Exploration Support Vehicles

NASA Technical Reports Server (NTRS)

Cognata, Thomas; Leimkuehler, Thomas; Ramaswamy, Balasubramaniam; Nayagam, Vedha; Hasan, Mohammad; Stephan, Ryan

2011-01-01

Water affords manifold benefits for human space exploration. Its properties make it useful for the storage of thermal energy as a Phase Change Material (PCM) in thermal control systems, in radiation shielding against Solar Particle Events (SPE) for the protection of crew members, and it is indisputably necessary for human life support. This paper envisions a single application for water which addresses these benefits for future exploration support vehicles and it describes recent experimental and modeling work that has been performed in order to arrive at a description of the thermal behavior of such a system. Experimental units have been developed and tested which permit the evaluation of the many parameters of design for such a system with emphasis on the latent energy content, temperature rise, mass, and interstitial material geometry. The experimental results are used to develop a robust and well correlated model which is intended to guide future design efforts toward the multi-purposed water PCM heat exchanger envisioned.

The future of bibliographic standards in a networked information environment

NASA Technical Reports Server (NTRS)

1997-01-01

The main mission of the CENDI Cataloging Working Group is to provide guidelines for cataloging practices that support the sharing of database records among the CENDI agencies, and that incorporate principles based on cost effectiveness and efficiency. Recent efforts include the extension of COSATI Guidelines for the Cataloging of Technical Reports to include non-print materials, and the mapping of each agency's export file structure to USMARC. Of primary importance is the impact of electronic documents and the distributed nature of the networked information environment. Topics discussed during the workshop include the following: Trade-offs in Cataloging and Indexing Internet Information; The Impact on Current and Future Standards; A Look at WWW Metadata Initiatives; Standards for Electronic Journals; The Present and Future Search Engines; The Roles for Text Analysis Software; Advanced Search Engine Meets Metathesaurus; Locator Schemes for Internet Resources; Identifying and Cataloging Web Document Types; In Search of a New Bibliographic Record. The videos in this set include viewgraphs of charts and related materials of the workshop.

Materials, Structures and Manufacturing: An Integrated Approach to Develop Expandable Structures

NASA Technical Reports Server (NTRS)

Belvin, W. Keith; Zander, Martin E.; Sleight, Daid W.; Connell, John; Holloway, Nancy; Palmieri, Frank

2012-01-01

Membrane dominated space structures are lightweight and package efficiently for launch; however, they must be expanded (deployed) in-orbit to achieve the desired geometry. These expandable structural systems include solar sails, solar power arrays, antennas, and numerous other large aperture devices that are used to collect, reflect and/or transmit electromagnetic radiation. In this work, an integrated approach to development of thin-film damage tolerant membranes is explored using advanced manufacturing. Bio-inspired hierarchical structures were printed on films using additive manufacturing to achieve improved tear resistance and to facilitate membrane deployment. High precision, robust expandable structures can be realized using materials that are both space durable and processable using additive manufacturing. Test results show this initial work produced higher tear resistance than neat film of equivalent mass. Future research and development opportunities for expandable structural systems designed using an integrated approach to structural design, manufacturing, and materials selection are discussed.

Final Technical Report

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

Lisa M. Daniels

2002-05-08

This project was very successful in terms of providing a unique source of information for rural communities and landowners. We are very pleased with the overall results and believe that this is a vital program for the sustainable development of wind energy. The outreach materials created by Windustry are filling a serious void in information about how local communities and rural landowners can participate in wind development projects. In our program implementation we learned how great the demand is for this type of information both through our hotline calls and website usage. We also realized that the materials require constantmore » updating and maintenance. There is a balance that needs to be found in printing the materials to have handouts ready at meetings for our primary target audience and more research and revisions for the website materials. All of this work is of an ongoing nature. Since this funding was awarded for one year, Windustry will be seeking other funding sources to continue the work in future years. Below is a summary of the Windustry accomplishments as well a sampling of website usage reports. Windustry is appreciative of the US DOE for its support of this wind energy industry work and the Wind Powering America initiative.« less

Retinal Implants for Blind Patients

NASA Astrophysics Data System (ADS)

Rothermel, Albrecht

Recently, very promising results have been obtained in clinical trials with eye-prostheses for the blind. There is a chance that advances in surgical techniques, microelectronics design, and material science may lead to the first really useful applications of retinal implants in the near future. This chapter will focus on the actual status of subretinal surgery and implant technologies. Opportunities and limitations of the different technologies will be discussed in terms of patients benefit and technological challenges. Finally, a vision on how the devices may work and look like in the future will be given.

Synthesis of discipline-based education research in physics

NASA Astrophysics Data System (ADS)

Docktor, Jennifer L.; Mestre, José P.

2014-12-01

This paper presents a comprehensive synthesis of physics education research at the undergraduate level. It is based on work originally commissioned by the National Academies. Six topical areas are covered: (1) conceptual understanding, (2) problem solving, (3) curriculum and instruction, (4) assessment, (5) cognitive psychology, and (6) attitudes and beliefs about teaching and learning. Each topical section includes sample research questions, theoretical frameworks, common research methodologies, a summary of key findings, strengths and limitations of the research, and areas for future study. Supplemental material proposes promising future directions in physics education research.

State-of-the-art low-cost solar reflector materials

NASA Astrophysics Data System (ADS)

Kennedy, C.; Jorgensen, G.

1994-11-01

Solar thermal technologies generate power by concentrating sunlight with large mirrors. The National Renewable Energy Laboratory (NREL) is working with industrial partners to develop the optical reflector materials needed for the successful deployment of this technology. The reflector materials must be low in cost and maintain high specular reflectance for extended lifetimes in severe outdoor environments. Currently, the best candidate materials for solar mirrors are silver-coated low-iron glass and silvered polymer films. Polymer reflectors are lighter in weight, offer greater flexibility in system design, and have the potential for lower cost than glass mirrors. In parallel with collaborative activities, several innovative candidate reflector-material constructions were investigated at NREL. The low-cost material requirement necessitates manufacturing compatible with mass-production techniques. Future cooperative efforts with the web-coating industry offers the promise of exciting new alternative materials and the potential for dramatic cost savings in developing advanced solar reflector materials.

OPTIMIZATION ON MATERIAL FLOW OF NON-METALIC MINERAL MATERIALS TOWARDS SUSTAINABLE SOCIETY

NASA Astrophysics Data System (ADS)

Sakamoto, Kouji; Nakayama, Hirofumi; Shimaoka, Takayuki; Hasegawa, Ryoji; Osako, Masahiro

Since non-metarilc mineral waste such as concrete mass, asphalt concrete mass, sand, slag and coal ash occupies 36% of total amount of waste generation and 26% of total amount of final disposal, it has significant influence on material flow of our country. Although the amount of non-metaril mineral wastes produced is expected to increase in the near future, demand of their application for recycled construction materials will decrease due to the reduction of public construction works and less use of materials in construction. The aim is to reduce environmental load caused by recycling and disposal of non metallic mineral materials, this study was conducted to evaluate the measurement for the reduction of environmental load like landfill amount and CO2 emission amount by controlling material flow of non metallic mineral materials in the year 2030 by linear programming.

Across the Board: Nam-Gyu Park.

PubMed

Park, Nam-Gyu

2016-09-22

In this series of articles, the board members of ChemSusChem discuss recent research articles that they consider of exceptional quality and importance for sustainability. This entry features Prof. Nam-Gyu Park, who highlights the recent work on mixed-cation mixed-anion perovskite materials toward high efficiency perovskite solar cells. He summarizes the work that has brought us to the current stage of research and suggests possible future paths for further advancement. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Agile manufacturing: The factory of the future

NASA Technical Reports Server (NTRS)

Loibl, Joseph M.; Bossieux, Terry A.

1994-01-01

The factory of the future will require an operating methodology which effectively utilizes all of the elements of product design, manufacturing and delivery. The process must respond rapidly to changes in product demand, product mix, design changes or changes in the raw materials. To achieve agility in a manufacturing operation, the design and development of the manufacturing processes must focus on customer satisfaction. Achieving greatest results requires that the manufacturing process be considered from product concept through sales. This provides the best opportunity to build a quality product for the customer at a reasonable rate. The primary elements of a manufacturing system include people, equipment, materials, methods and the environment. The most significant and most agile element in any process is the human resource. Only with a highly trained, knowledgeable work force can the proper methods be applied to efficiently process materials with machinery which is predictable, reliable and flexible. This paper discusses the affect of each element on the development of agile manufacturing systems.

Rare earths: Market disruption, innovation, and global supply chains

USGS Publications Warehouse

Eggert, Roderick; Wadia, Cyrus; Anderson, Corby; Bauer, Diana; Fields, Fletcher; Meinert, Lawrence D.; Taylor, Patrick

2016-01-01

Rare earths, sometimes called the vitamins of modern materials, captured public attention when their prices increased more than ten-fold in 2010 and 2011. As prices fell between 2011 and 2016, rare earths receded from public view—but less visibly they became a major focus of innovative activity in companies, government laboratories and universities. Geoscientists worked to better understand the resource base and improve our knowledge about mineral deposits that will be mines in the future. Process engineers carried out research that is making primary production and recycling more efficient. Materials scientists and engineers searched for substitutes that will require fewer or no rare earths while providing properties comparable or superior to those of existing materials. As a result, even though global supply chains are not significantly different now than they were before the market disruption, the innovative activity motivated by the disruption likely will have far-reaching, if unpredictable, consequences for supply chains of rare earths in the future.

Use of Atmospheric-Pressure Plasma Jet for Polymer Surface Modification: An Overview

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

Kuettner, Lindsey A.

Atmospheric-pressure plasma jets (APPJs) are playing an increasingly important role in materials processing procedures. Plasma treatment is a useful tool to modify surface properties of materials, especially polymers. Plasma reacts with polymer surfaces in numerous ways thus the type of process gas and plasma conditions must be explored for chosen substrates and materials to maximize desired properties. This report discusses plasma treatments and looks further into atmospheric-pressure plasma jets and the effects of gases and plasma conditions. Following the short literature review, a general overview of the future work and research at Los Alamos National Laboratory (LANL) is discussed.

Promoviendo un Futuro Saludable: Manual de Entrenamiento para Educadores de Salud e Instructores que Trabajan con Jovenes Promotores de Salud, Jovenes Consejeros o Educadores y Voluntarios (Promoting a Healthy Future: Training Manual for Health Educators and Instructors Who Work with Young Health Promoters, Young Counselors or Educators and Volunteers).

ERIC Educational Resources Information Center

Duran, Carmen; Cuchi, Paloma

This manual is designed to help the Latino community in its work of incorporating young people into disease prevention efforts and health education. It provides basic information on 12 health themes along with suggestions and resource materials for the instructor. The young people trained through this manual may work in a number of education and…

Non-destructive inspection approach using ultrasound to identify the material state for amorphous and semi-crystalline materials

NASA Astrophysics Data System (ADS)

Jost, Elliott; Jack, David; Moore, David

2018-04-01

At present, there are many methods to identify the temperature and phase of a material using invasive techniques. However, most current methods require physical contact or implicit methods utilizing light reflectance of the specimen. This work presents a nondestructive inspection method using ultrasonic wave technology that circumvents these disadvantages to identify phase change regions and infer the temperature state of a material. In the present study an experiment is performed to monitor the time of flight within a wax as it undergoes melting and the subsequent cooling. Results presented in this work show a clear relationship between a material's speed of sound and its temperature. The phase change transition of the material is clear from the time of flight results, and in the case of the investigated material, this change in the material state occurs over a range of temperatures. The range of temperatures over which the wax material melts is readily identified by speed of sound represented as a function of material temperature. The melt temperature, obtained acoustically, is validated using Differential Scanning Calorimetry (DSC), which uses shifts in heat flow rates to identify phase transition temperature ranges. The investigated ultrasonic NDE method has direct applications in many industries, including oil and gas, food and beverage, and polymer composites, in addition to many implications for future capabilities of nondestructive inspection of multi-phase materials.

Occupational exposures associated with work-related asthma and work-related wheezing among U.S. workers.

PubMed

Arif, Ahmed A; Delclos, George L; Whitehead, Lawrence W; Tortolero, Susan R; Lee, Eun S

2003-10-01

National estimates of occupational asthma (OA) in the United States are sparse. Using data from the Third National Health and Nutrition Examination Survey (NHANES III) 1988-1994, we analyzed associations between occupation and work-related asthma and work-related wheezing among U.S. workers. This study identified several occupations that were at risk of developing work-related asthma and/or wheezing, with cleaners and equipment cleaners showing the highest risks. Other major occupations identified were farm and agriculture; entertainment; protective services; construction; mechanics and repairers; textile; fabricators and assemblers; other transportation and material moving occupations; freight, stock, and material movers; and motor vehicle operators. The population attributable risks for work-related asthma and work-related wheezing were 26% and 27%, respectively. This study adds evidence to the literature that identifies work-related asthma as an important public health problem. Several occupations are targeted for additional evaluation and study. Of particular interest are cleaners, which are being increasingly reported as a risk group for asthma. Future intervention strategies need to be developed for effective control and prevention of asthma in the workplace. Copyright 2003 Wiley-Liss, Inc.

Design & Performance of Wearable Ultra Wide Band Textile Antenna for Medical Applications

NASA Astrophysics Data System (ADS)

Singh, Nikhil; Singh, Ashutosh Kumar; Singh, Vinod Kumar

2015-02-01

The concept of wearable products such as textile antenna are being developed which are capable of monitoring, alerting and demanding attention whenever hospital emergency is needed, hence minimizing labour and resource. In the proposed work by using textile material as a substrate the ultra wideband antenna is designed especially for medical applications.Simulated and measured results here shows that the proposed antenna design meets the requirements of wide working bandwidth and provides 13.08 GHz bandwidth with very small size, washable (if using conductive thread for conductive parts) and flexible materials. Results in terms of bandwidth, radiation pattern, return loss as well as gain and efficiency are presented to validate the usefulness of the current proposed design. The work done here has many implications for future research and it could help patients with such flexible and comfortable medical monitoring techniques.

Unleashing elastic energy: dynamics of energy release in rubber bands and impulsive biological systems

NASA Astrophysics Data System (ADS)

Ilton, Mark; Cox, Suzanne; Egelmeers, Thijs; Patek, S. N.; Crosby, Alfred J.

Impulsive biological systems - which include mantis shrimp, trap-jaw ants, and venus fly traps - can reach high speeds by using elastic elements to store and rapidly release energy. The material behavior and shape changes critical to achieving rapid energy release in these systems are largely unknown due to limitations of materials testing instruments operating at high speed and large displacement. In this work, we perform fundamental, proof-of-concept measurements on the tensile retraction of elastomers. Using high speed imaging, the kinematics of retraction are measured for elastomers with varying mechanical properties and geometry. Based on the kinematics, the rate of energy dissipation in the material is determined as a function of strain and strain-rate, along with a scaling relation which describes the dependence of maximum velocity on material properties. Understanding this scaling relation along with the material failure limits of the elastomer allows the prediction of material properties required for optimal performance. We demonstrate this concept experimentally by optimizing for maximum velocity in our synthetic model system, and achieve retraction velocities that exceed those in biological impulsive systems. This model system provides a foundation for future work connecting continuum performance to molecular architecture in impulsive systems.

Space Station Freedom Gateway to the Future

NASA Technical Reports Server (NTRS)

1992-01-01

The first inhabited outpost on the frontier of space will be a place to live, work, and discover. Experiments conducted on Freedom will advance scientific knowledge about our world, our environment, and ourselves. We will learn how to adapt to the space environment and to build and operate new spacecraft with destinations far beyond Earth, continuing the tradition of exploration that began with a journey to the Moon. What we learn from living and working on Freedom will strengthen our expertise in science and engineering, promote national research and development initiatives and inspire another generation of Americans to push forward and onward. On the eve of the 21st century, Space Station Freedom will be our gateway to the future. This material covers gateways to space, research, discovery, utilization, benefits, and NASA.

Translational Research in Behavior Analysis: Historical Traditions and Imperative for the Future

ERIC Educational Resources Information Center

Mace, F. Charles; Critchfield, Thomas S.

2010-01-01

"Pure basic" science can become detached from the natural world that it is supposed to explain. "Pure applied" work can become detached from fundamental processes that shape the world it is supposed to improve. Neither demands the intellectual support of a broad scholarly community or the material support of society. Translational research can do…

Effects of carbonization conditions on properties of bamboo pellets

Treesearch

Zhijia Liu; Zehui Jiang; Zhiyong Cai; Benhua Fei; Yan Yu; Xing' e Liu

2013-01-01

Bamboo is a biomass material and has great potential as a bio-energy resource of the future in China. Bamboo pellets were successfully manufactured using a laboratory pellet mill in preliminary work. This study was therefore carried out to investigate the effect of carbonization conditions (temperature and time) on properties of bamboo pellets and to evaluate product...

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.

Nanophotonic implementation of optoelectrowetting for microdroplet actuation

NASA Astrophysics Data System (ADS)

Collier, Christopher M.; Hill, Kyle A.; DeWachter, Mark A.; Huizing, Alexander M.; Holzman, Jonathan F.

2015-02-01

The development and ultimate operation of a nanocomposite high-aspect-ratio photoinjection (HARP) device is presented in this work. The device makes use of a nanocomposite material as the optically active layer and the device achieves a large optical penetration depth with a high aspect ratio which provides a strong actuation force far away from the point of photoinjection. The nanocomposite material can be continuously illuminated and the position of the microdroplets can, therefore, be controlled to diffraction limited resolution. The nanocomposite HARP device shows great potential for future on-chip applications.

Composite material impregnation unit

NASA Technical Reports Server (NTRS)

Wilkinson, S. P.; Marchello, J. M.; Johnston, N. J.

1993-01-01

This memorandum presents an introduction to the NASA multi-purpose prepregging unit which is now installed and fully operational at the Langley Research Center in the Polymeric Materials Branch. A description of the various impregnation methods that are available to the prepregger are presented. Machine operating details and protocol are provided for its various modes of operation. These include, where appropriate, the related equations for predicting the desired prepreg specifications. Also, as the prepregger is modular in its construction, each individual section is described and discussed. Safety concerns are an important factor and a chapter has been included that highlights the major safety features. Initial experiences and observations for fiber impregnation are described. These first observations have given great insight into the areas of future work that need to be addressed. Future memorandums will focus on these individual processes and their related problems.

Nuclear Materials Science

NASA Astrophysics Data System (ADS)

Whittle, Karl

2016-06-01

Concerns around global warming have led to a nuclear renaissance in many countries, meanwhile the nuclear industry is warning already of a need to train more nuclear engineers and scientists, who are needed in a range of areas from healthcare and radiation detection to space exploration and advanced materials as well as for the nuclear power industry. Here Karl Whittle provides a solid overview of the intersection of nuclear engineering and materials science at a level approachable by advanced students from materials, engineering and physics. The text explains the unique aspects needed in the design and implementation of materials for use in demanding nuclear settings. In addition to material properties and their interaction with radiation the book covers a range of topics including reactor design, fuels, fusion, future technologies and lessons learned from past incidents. Accompanied by problems, videos and teaching aids the book is suitable for a course text in nuclear materials and a reference for those already working in the field.

Growing and testing mycelium bricks as building insulation materials

NASA Astrophysics Data System (ADS)

Xing, Yangang; Brewer, Matthew; El-Gharabawy, Hoda; Griffith, Gareth; Jones, Phil

2018-02-01

In order to improve energy performance of buildings, insulation materials (such as mineral glass and rock wools, or fossil fuel-based plastic foams) are being used in increasing quantities, which may lead to potential problem with materials depletions and landfill disposal. One sustainable solution suggested is the use of bio-based, biodegradable materials. A number of attempts have been made to develop biomaterials, such as sheep wood, hemcrete or recycled papers. In this paper, a novel type of bio insulation materials - mycelium is examined. The aim is to produce mycelium materials that could be used as insulations. The bio-based material was required to have properties that matched existing alternatives, such as expanded polystyrene, in terms of physical and mechanical characteristics but with an enhanced level of biodegradability. The testing data showed mycelium bricks exhibited good thermal performance. Future work is planned to improve growing process and thermal performance of the mycelium bricks.

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.

The NASA MSFC Electrostatic Levitation (ESL) Laboratory: Summary of Capabilities, Recent Upgrades, and Future Work

NASA Technical Reports Server (NTRS)

SanSoucie, Michael P.; Vermilion, David J.; Rogers, Jan R.

2015-01-01

The NASA Marshall Space Flight Center (MSFC) electrostatic levitation (ESL) laboratory has a long history of providing materials research and thermophysical property data. A summary of the labs capabilities, recent upgrades, and ongoing and future work will be provided. The laboratory has recently added two new capabilities to its main levitation chamber: a rapid quench system and an oxygen control system. The rapid quench system allows samples to be dropped into a quench vessel that can be filled with a low melting point material, such as a gallium or indium alloy. Thereby allowing rapid quenching of undercooled liquid metals. The oxygen control system consists of an oxygen sensor, oxygen pump, and a control unit. The sensor is a potentiometric device that determines the difference in oxygen activity between two gas compartments separated by an electrolyte, which is yttria-stabilized zirconia. The pump utilizes coulometric titration to either add or remove oxygen. The system is controlled by a desktop control unit, which can also be accessed via a computer. This system allows the oxygen partial pressure within the vacuum chamber to be measured and controlled, theoretically in the range from 10-36 to 100 bar. The ESL laboratory also has an emissometer, called the High-Temperature Emissivity Measurement System (HiTEMS). This system measures the spectral emissivity of materials from 600degC to 3,000degC. The system consists of a vacuum chamber, a black body source, and a Fourier Transform Infrared Spectrometer (FTIR). The system utilizes optics to swap the signal between the sample and the black body. The system was originally designed to measure the hemispherical spectral emissivity of levitated samples, which are typically 2.5mm spheres. Levitation allows emissivity measurements of molten samples, but more work is required to develop this capability. The system is currently setup measure the near-normal spectral emissivity of stationary samples, which has been used to take measurements of ablative materials, rocket nozzle coating materials, and materials for spacecraft instruments.

Affordable Development and Optimization of CERMET Fuels for NTP Ground Testing

NASA Technical Reports Server (NTRS)

Hickman, Robert R.; Broadway, Jeramie W.; Mireles, Omar R.

2014-01-01

CERMET fuel materials for Nuclear Thermal Propulsion (NTP) are currently being developed at NASA's Marshall Space Flight Center. The work is part of NASA's Advanced Space Exploration Systems Nuclear Cryogenic Propulsion Stage (NCPS) Project. The goal of the FY12-14 project is to address critical NTP technology challenges and programmatic issues to establish confidence in the affordability and viability of an NTP system. A key enabling technology for an NCPS system is the fabrication of a stable high temperature nuclear fuel form. Although much of the technology was demonstrated during previous programs, there are currently no qualified fuel materials or processes. The work at MSFC is focused on developing critical materials and process technologies for manufacturing robust, full-scale CERMET fuels. Prototypical samples are being fabricated and tested in flowing hot hydrogen to understand processing and performance relationships. As part of this initial demonstration task, a final full scale element test will be performed to validate robust designs. The next phase of the project will focus on continued development and optimization of the fuel materials to enable future ground testing. The purpose of this paper is to provide a detailed overview of the CERMET fuel materials development plan. The overall CERMET fuel development path is shown in Figure 2. The activities begin prior to ATP for a ground reactor or engine system test and include materials and process optimization, hot hydrogen screening, material property testing, and irradiation testing. The goal of the development is to increase the maturity of the fuel form and reduce risk. One of the main accomplishmens of the current AES FY12-14 project was to develop dedicated laboratories at MSFC for the fabrication and testing of full length fuel elements. This capability will enable affordable, near term development and optimization of the CERMET fuels for future ground testing. Figure 2 provides a timeline of the development and optimization tasks for the AES FY15-17 follow on program.

Contributive research in compound semiconductor material and related devices

NASA Astrophysics Data System (ADS)

Twist, James R.

1988-05-01

The objective of this program was to provide the Electronic Device Branch (AFWAL/AADR) with the support needed to perform state of the art electronic device research. In the process of managing and performing on the project, UES has provided a wide variety of scientific and engineering talent who worked in-house for the Avionics Laboratory. These personnel worked on many different types of research programs from gas phase microwave driven lasers, CVD and MOCVD of electronic materials to Electronic Device Technology for new devices. The fields of research included MBE and theoretical research in this novel growth technique. Much of the work was slanted towards the rapidly developing technology of GaAs and the general thrust of the research that these tasks started has remained constant. This work was started because the Avionics Laboratory saw a chance to advance the knowledge and level of the current device technology by working in the compounds semiconductor field. UES is pleased to have had the opportunity to perform on this program and is looking forward to future efforts with the Avionics Laboratory.

The roles of energy and material efficiency in meeting steel industry CO2 targets.

PubMed

Milford, Rachel L; Pauliuk, Stefan; Allwood, Julian M; Müller, Daniel B

2013-04-02

Identifying strategies for reducing greenhouse gas emissions from steel production requires a comprehensive model of the sector but previous work has either failed to consider the whole supply chain or considered only a subset of possible abatement options. In this work, a global mass flow analysis is combined with process emissions intensities to allow forecasts of future steel sector emissions under all abatement options. Scenario analysis shows that global capacity for primary steel production is already near to a peak and that if sectoral emissions are to be reduced by 50% by 2050, the last required blast furnace will be built by 2020. Emissions reduction targets cannot be met by energy and emissions efficiency alone, but deploying material efficiency provides sufficient extra abatement potential.

Smart Materials Based on DNA Aptamers: Taking Aptasensing to the Next Level

PubMed Central

Mastronardi, Emily; Foster, Amanda; Zhang, Xueru; DeRosa, Maria C.

2014-01-01

“Smart” materials are an emerging category of multifunctional materials with physical or chemical properties that can be controllably altered in response to an external stimulus. By combining the standard properties of the advanced material with the unique ability to recognize and adapt in response to a change in their environment, these materials are finding applications in areas such as sensing and drug delivery. While the majority of these materials are responsive to physical or chemical changes, a particularly exciting area of research seeks to develop smart materials that are sensitive to specific molecular or biomolecular stimuli. These systems require the integration of a molecular recognition probe specific to the target molecule of interest. The ease of synthesis and labeling, low cost, and stability of DNA aptamers make them uniquely suited to effectively serve as molecular recognition probes in novel smart material systems. This review will highlight current work in the area of aptamer-based smart materials and prospects for their future applications. PMID:24553083

NIST Automated Manufacturing Research Facility (AMRF): March 1987

NASA Technical Reports Server (NTRS)

Herbert, Judith E. (Editor); Kane, Richard (Editor)

1987-01-01

The completion and advances to the NIST Automated Manufacturing Research Facility (AMRF) is described in this video. The six work stations: (1) horizontal machining; (2) vertical machining; (3) turning machinery; (4) cleaning and deburring; (5) materials handling; and (6) inspection are shown and uses for each workstation are cited. Visiting researchers and scientists within NIST describe the advantages of each of the workstations, what the facility is used for, future applications for the technological advancements from the AMRF, including examples of how AMRF technology is being transferred to the U.S. Navy industry and discuss future technological goals for the facility.

Custom Machines Advance Composite Manufacturing

NASA Technical Reports Server (NTRS)

2012-01-01

Here is a brief list of materials that NASA will not be using to construct spacecraft: wood, adobe, fiberglass, bone. While it might be obvious why these materials would not make for safe space travel, they do share a common characteristic with materials that may well be the future foundation of spacecraft design: They all are composites. Formed of two or more unlike materials - such as cellulose and lignin in the case of wood, or glass fibers and plastic resin in the case of fiberglass-composites provide enhanced mechanical and physical properties through the combination of their constituent materials. For this reason, composites are used in everything from buildings, bathtubs, and countertops to boats, racecars, and sports equipment. NASA continually works to develop new materials to enable future space missions - lighter, less expensive materials that can still withstand the extreme demands of space travel. Composites such as carbon fiber materials offer promising solutions in this regard, providing strength and stiffness comparable to metals like aluminum but with less weight, allowing for benefits like better fuel efficiency and simpler propulsion system design. Composites can also be made fatigue tolerant and thermally stable - useful in space where temperatures can swing hundreds of degrees. NASA has recently explored the use of composites for aerospace applications through projects like the Composite Crew Module (CCM), a composite-constructed version of the aluminum-lithium Multipurpose Crew Capsule. The CCM was designed to give NASA engineers a chance to gain valuable experience developing and testing composite aerospace structures.

Extraterrestrial materials processing

NASA Technical Reports Server (NTRS)

Steurer, W. H.

1982-01-01

The first year results of a multi-year study of processing extraterrestrial materials for use in space are summarized. Theoretically, there are potential major advantages to be derived from the use of such materials for future space endeavors. The types of known or postulated starting raw materials are described including silicate-rich mixed oxides on the Moon, some asteroids and Mars; free metals in some asteroids and in small quantities in the lunar soil; and probably volatiles like water and CO2 on Mars and some asteroids. Candidate processes for space materials are likely to be significantly different from their terrestrial counterparts largely because of: absence of atmosphere; lack of of readily available working fluids; low- or micro-gravity; no carbon-based fuels; readily available solar energy; and severe constraints on manned intervention. The extraction of metals and oxygen from lunar material by magma electrolysis or by vapor/ion phase separation appears practical.

Multimodal and self-healable interfaces enable strong and tough graphene-derived materials

NASA Astrophysics Data System (ADS)

Liu, Yilun; Xu, Zhiping

2014-10-01

Recent studies have shown that graphene-derived materials not only feature outstanding multifunctional properties, but also act as model materials to implant nanoscale structural engineering insights into their macroscopic performance optimization. In this work, we explore strengthening and toughening strategies of this class of materials by introducing multimodal crosslinks, including long, strong and short, self-healable ones. We identify two failure modes by fracturing functionalized graphene sheets or their crosslinks, and the role of brick-and-mortar hierarchy in mechanical enhancement. Theoretical analysis and atomistic simulation results show that multimodal crosslinks synergistically transfer tensile load to enhance the strength, whereas reversible rupture and formation of healable crosslinks improve the toughness. These findings lay the ground for future development of high-performance paper-, fiber- or film-like macroscopic materials from low-dimensional structures with engineerable interfaces.

Local structure studies of materials using pair distribution function analysis

NASA Astrophysics Data System (ADS)

Peterson, Joseph W.

A collection of pair distribution function studies on various materials is presented in this dissertation. In each case, local structure information of interest pushes the current limits of what these studies can accomplish. The goal is to provide insight into the individual material behaviors as well as to investigate ways to expand the current limits of PDF analysis. Where possible, I provide a framework for how PDF analysis might be applied to a wider set of material phenomena. Throughout the dissertation, I discuss 0 the capabilities of the PDF method to provide information pertaining to a material's structure and properties, ii) current limitations in the conventional approach to PDF analysis, iii) possible solutions to overcome certain limitations in PDF analysis, and iv) suggestions for future work to expand and improve the capabilities PDF analysis.

Touch the Future: Discovering Abilities through Technology for Living, Learning, Working and Playing. Southeast Regional Conference (3rd, Atlanta, Georgia, April 10-12, 1991).

ERIC Educational Resources Information Center

Georgia State Dept. of Human Resources, Atlanta. Div. of Rehabilitation Services.

This packet of materials was originally intended for participants in a 1991 conference on assistive technology for the disabled. After a detailed listing of the conference schedule, individual sections provide abstracts, biographical sketches, and summaries concerning the following conference topics: blending, computer labs, family, grants and…

Paternity Leave: Current Status and Future Prospects. Working Paper No. 157.

ERIC Educational Resources Information Center

Pleck, Joseph H.

This paper examines current patterns and trends in the availability and use of parental leave by U.S. fathers. Introductory material focuses on legal and administrative contexts of parental leave and parental leave policies available to employed mothers. The main discussion uses U.S. and Swedish data to explore (1) long-term paid leave at the time…

Families and Futures. A Resource for Developing Home and Family Life Education Programs. Revised Working Materials.

ERIC Educational Resources Information Center

Washington Office of the State Superintendent of Public Instruction, Olympia.

This curriculum guide was designed to help teachers in strengthening the ability of students from middle school through grade 12 to recognize complex problems, examine competing points of view, and engage in dialogue leading to practical solutions for issues that affect individuals and families and ultimately the world. The course integrates the…

Films of Carbon Nanomaterials for Transparent Conductors

PubMed Central

Ho, Xinning; Wei, Jun

2013-01-01

The demand for transparent conductors is expected to grow rapidly as electronic devices, such as touch screens, displays, solid state lighting and photovoltaics become ubiquitous in our lives. Doped metal oxides, especially indium tin oxide, are the commonly used materials for transparent conductors. As there are some drawbacks to this class of materials, exploration of alternative materials has been conducted. There is an interest in films of carbon nanomaterials such as, carbon nanotubes and graphene as they exhibit outstanding properties. This article reviews the synthesis and assembly of these films and their post-treatment. These processes determine the film performance and understanding of this platform will be useful for future work to improve the film performance. PMID:28809267

LDRD Final Report 15-ERD-037 Matthews

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

Matthews, Manyalibo J.

2017-10-26

The physics and materials science involved in laser materials processing of metals was studied experimentally using custom-built test beds and in situ diagnostics. Special attention was given to laser-based powder bed fusion additive manufacturing processes, a technology critically important to the stockpile stewardship program in NNSA. New light has been shed on several phenomena such as laser-driven spatter, material displacement and morphology changes. The results presented here and in publications generated by this work have proven impactful and useful to both internal and external communities. New directions in additive manufacturing research at LLNL have been enabled, along with new scientificmore » capabilities that can serve future program needs.« less

Carbon Nanotube Chopped Fiber for Enhanced Properties in Additive Manufacturing

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

Menchhofer, Paul A.; Johnson, Joseph E.; Lindahl, John M.

2016-06-06

Nanocomp Technologies, Inc. is working with Oak Ridge National Laboratory to develop carbon nanotube (CNT) composite materials and evaluate their use in additive manufacturing (3D printing). The first phase demonstrated feasibility and improvements for carbon nanotube (CNT)- acrylonitrile butadiene styrene (ABS) composite filaments use in additive manufacturing, with potential future work centering on further improvements. By focusing the initial phase on standard processing methods (developed mainly for the incorporation of carbon fibers in ABS) and characterization techniques, a basis of knowledge for the incorporation of CNTs in ABS was learned. The ability to understand the various processing variables is criticalmore » to the successful development of these composites. From the degradation effects on ABS (caused by excessive temperatures), to the length of time the ABS is in the melt state, to the order of addition of constituents, and also to the many possible mixing approaches, a workable flow sequence that addresses each processing step is critical to the final material properties. Although this initial phase could not deal with each of these variables in-depth, a future study is recommended that will build on the lessons learned for this effort.« less

Study of the time varying properties of flax fiber reinforced composites

NASA Astrophysics Data System (ADS)

Stochioiu, Constantin; Chettah, Ameur; Piezel, Benoit; Fontaine, Stéphane; Gheorghiu, Horia-Miron

2018-02-01

Bio materials have seen an increase of interest from the scientific community and the industry as a possible future generation of mass produced materials, some of the main arguments being their renewability, low production costs and recyclability. The current work is focused on the experimental data required for the viscoelastic characterization of a composite material. Similar work has been conducted on different types of composite materials by Tuttle and Brinson [1] who verified for a carbon epoxy laminate the possibility of long term predicament of creep. Nordin et al [2] studied paper impregnated with phenol-formaldehyde under compression. Muliana [3] conducted experiments on E-glass/vinyl ester materials. Behavior characterization was based on a model presented by Schapery [4]. The main objective of this work is to understand the mechanical behaviors of bio-laminates structures subjected to long and severe operating conditions. The studied material is a bio composite laminate consisting in long flax fibers embedded in an epoxy resin system. The laminates were obtained from pre-impregnated unidirectional fibers, which were cured though a thermo-compression cycle followed by a post curing cycle. Test specimens were cut down to sizes, with the help of an electric saw. The concerned fiber direction was 0° with sample dimensions of 250x25x2 mm. First, testing consisted in quasi static mechanical tests. Second, to characterize linear viscoelastic behavior of the bio-laminates, creep - recovery tests with multiple load levels have been performed for the chosen fiber direction.

Space Technology Plasma Issues in 2001

NASA Technical Reports Server (NTRS)

Garrett, Henry (Editor); Feynman, Joan (Editor); Gabriel, Stephen (Editor)

1986-01-01

The purpose of the workshop was to identify and discuss plasma issues that need to be resolved during the next 10 to 20 years (circa 2001) to facilitate the development of the advanced space technology that will be required 20 or 30 years into the future. The workshop consisted of 2 days of invited papers and 2 sessions of contributed poster papers. During the third day the meeting broke into 5 working groups, each of which held discussions and then reported back to the conference as a whole. The five panels were: Measurements Technology and Active Experiments Working Group; Advanced High-Voltage, High-Power and Energy-Storage Space Systems Working Group; Large Structures and Tethers Working Group; Plasma Interactions and Surface/Materials Effects Working Group; and Beam Plasmas, Electronic Propulsion and Active Experiments Using Beams Working Group.

A multiscale microstructural approach to ductile-phase toughened tungsten for plasma-facing materials

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

Nguyen, Ba Nghiep; Henager, Jr., Charles H.; Overman, Nicole R.

Increasing fracture toughness and modifying the ductile-brittle transition temperature of a tungsten-alloy relative to pure tungsten has been shown to be feasible by ductile-phase toughening (DPT) of tungsten for future plasma-facing materials for fusion energy. In DPT, a ductile phase is included in a brittle tungsten matrix to increase the overall work of fracture for the material. This research models the deformation behavior of DPT tungsten materials, such as tungsten-copper composites, using a multiscale modeling approach that involves a microstructural dual-phase (copper-tungsten) region of interest where the constituent phases are finely discretized and are described by a continuum damage mechanicsmore » model. Large deformation, damage, and fracture are allowed to occur and are modeled in a region that is connected to adjacent homogenized elastic regions to form a macroscopic structure, such as a test specimen. The present paper illustrates this multiscale modeling approach to analyze unnotched and single-edge notched (SENB) tungsten-copper composite specimens subjected to three-point bending. The predicted load-displacement responses and crack propagation patterns are compared to the corresponding experimental results to validate the model. Furthermore, such models may help design future DPT composite configurations for fusion materials, including volume fractions of ductile phase and microstructural optimization.« less

A multiscale microstructural approach to ductile-phase toughened tungsten for plasma-facing materials

DOE PAGES

Nguyen, Ba Nghiep; Henager, Jr., Charles H.; Overman, Nicole R.; ...

2018-05-23

Increasing fracture toughness and modifying the ductile-brittle transition temperature of a tungsten-alloy relative to pure tungsten has been shown to be feasible by ductile-phase toughening (DPT) of tungsten for future plasma-facing materials for fusion energy. In DPT, a ductile phase is included in a brittle tungsten matrix to increase the overall work of fracture for the material. This research models the deformation behavior of DPT tungsten materials, such as tungsten-copper composites, using a multiscale modeling approach that involves a microstructural dual-phase (copper-tungsten) region of interest where the constituent phases are finely discretized and are described by a continuum damage mechanicsmore » model. Large deformation, damage, and fracture are allowed to occur and are modeled in a region that is connected to adjacent homogenized elastic regions to form a macroscopic structure, such as a test specimen. The present paper illustrates this multiscale modeling approach to analyze unnotched and single-edge notched (SENB) tungsten-copper composite specimens subjected to three-point bending. The predicted load-displacement responses and crack propagation patterns are compared to the corresponding experimental results to validate the model. Furthermore, such models may help design future DPT composite configurations for fusion materials, including volume fractions of ductile phase and microstructural optimization.« less

Overview of Materials Qualification Needs for Metal Additive Manufacturing

NASA Astrophysics Data System (ADS)

Seifi, Mohsen; Salem, Ayman; Beuth, Jack; Harrysson, Ola; Lewandowski, John J.

2016-03-01

This overview highlights some of the key aspects regarding materials qualification needs across the additive manufacturing (AM) spectrum. AM technology has experienced considerable publicity and growth in the past few years with many successful insertions for non-mission-critical applications. However, to meet the full potential that AM has to offer, especially for flight-critical components (e.g., rotating parts, fracture-critical parts, etc.), qualification and certification efforts are necessary. While development of qualification standards will address some of these needs, this overview outlines some of the other key areas that will need to be considered in the qualification path, including various process-, microstructure-, and fracture-modeling activities in addition to integrating these with lifing activities targeting specific components. Ongoing work in the Advanced Manufacturing and Mechanical Reliability Center at Case Western Reserve University is focusing on fracture and fatigue testing to rapidly assess critical mechanical properties of some titanium alloys before and after post-processing, in addition to conducting nondestructive testing/evaluation using micro-computerized tomography at General Electric. Process mapping studies are being conducted at Carnegie Mellon University while large area microstructure characterization and informatics (EBSD and BSE) analyses are being conducted at Materials Resources LLC to enable future integration of these efforts via an Integrated Computational Materials Engineering approach to AM. Possible future pathways for materials qualification are provided.

Aerial Vehicles to Detect Maximum Volume of Plume Material Associated with Habitable Areas in Extreme Environments

NASA Technical Reports Server (NTRS)

Gunasekara, Onalli; Wong, Uland Y.; Furlong, Michael P.; Dille, Michael

2017-01-01

Current technologies of exploring habitable areas of icy moons are limited to flybys of space probes. This research project addresses long-term navigation of icy moons by developing a MATLAB adjustable trajectory based on the volume of plume material observed. Plumes expose materials from the sub-surface without accessing the subsurface. Aerial vehicles capable of scouting vapor plumes and detecting maximum plume material volumes, which are considered potentially habitable in inhospitable environments, would enable future deep-space missions to search for extraterrestrial organisms on the surface of icy moons. Although this platform is still a prototype, it demonstrates the potential aerial vehicles can have in improving the capabilities of long-term space navigation and enabling technology for detecting life in extreme environments. Additionally, this work is developing the capabilities that could be utilized as a platform for space biology research. For example, aerial vehicles that are sent to map extreme environments of icy moons or the planet Mars, could also carry small payloads with automated cell-biology experiments, designed to probe the biological response of low-gravity and high-radiation planetary environments, serving as a pathfinder for future human missions.

Micromechanical models to guide the development of synthetic ‘brick and mortar’ composites

NASA Astrophysics Data System (ADS)

Begley, Matthew R.; Philips, Noah R.; Compton, Brett G.; Wilbrink, David V.; Ritchie, Robert O.; Utz, Marcel

2012-08-01

This paper describes a micromechanical analysis of the uniaxial response of composites comprising elastic platelets (bricks) bonded together with thin elastic perfectly plastic layers (mortar). The model yields closed-form results for the spatial variation of displacements in the bricks as a function of constituent properties, which can be used to calculate the effective properties of the composite, including elastic modulus, strength and work-to-failure. Regime maps are presented which indicate critical stresses for failure of the bricks and mortar as a function of constituent properties and brick architecture. The solution illustrates trade-offs between elastic modulus, strength and dissipated work that are a result of transitions between various failure mechanisms associated with brick rupture and rupture of the interfaces. Detailed scaling relationships are presented with the goal of providing material developers with a straightforward means to identify synthesis targets that balance competing mechanical behaviors and optimize material response. Ashby maps are presented to compare potential brick and mortar composites with existing materials, and identify future directions for material development.

KSC-06pd0969

NASA Image and Video Library

2006-06-01

KENNEDY SPACE CENTER, FLA. - Inside the Space Station Processing Facility at NASA's Kennedy Space Center, an overhead crane carries the Columbus module toward a work stand. Columbus is the European Space Agency's research laboratory for the International Space Station. Once on the work stand , it will be prepared for delivery to the space station on a future space shuttle mission. Columbus will expand the research facilities of the station and provide researchers with the ability to conduct numerous experiments in the area of life, physical and materials sciences. Photo credit: NASA/Jim Grossmann

Advancing the Oxygen Generation Assembly Design to Increase Reliability and Reduce Costs for a Future Long Duration Mission

NASA Technical Reports Server (NTRS)

Takada, Kevin C.; Ghariani, Ahmed E.; Van Keuren,

2015-01-01

The state-of-the-art Oxygen Generation Assembly (OGA) has been reliably producing breathing oxygen for the crew aboard the International Space Station (ISS) for over eight years. Lessons learned from operating the ISS OGA have led to proposing incremental improvements to advance the baseline design for use in a future long duration mission. These improvements are intended to reduce system weight, crew maintenance time and resupply mass from Earth while increasing reliability. The proposed improvements include replacing the cell stack membrane material, deleting the nitrogen purge equipment, replacing the hydrogen sensors, deleting the wastewater interface, replacing the hydrogen dome and redesigning the cell stack power supply. The development work to date will be discussed and forward work will be outlined. Additionally, a redesigned system architecture will be proposed.

Solution processing of chalcogenide materials using thiol-amine "alkahest" solvent systems.

PubMed

McCarthy, Carrie L; Brutchey, Richard L

2017-05-02

Macroelectronics is a major focus in electronics research and is driven by large area applications such as flat panel displays and thin film solar cells. Innovations for these technologies, such as flexible substrates and mass production, will require efficient and affordable semiconductor processing. Low-temperature solution processing offers mild deposition methods, inexpensive processing equipment, and the possibility of high-throughput processing. In recent years, the discovery that binary "alkahest" mixtures of ethylenediamine and short chain thiols possess the ability to dissolve bulk inorganic materials to yield molecular inks has lead to the wide study of such systems and the straightforward recovery of phase pure crystalline chalcogenide thin films upon solution processing and mild annealing of the inks. In this review, we recount the work that has been done toward elucidating the scope of this method for the solution processing of inorganic materials for use in applications such as photovoltaic devices, electrocatalysts, photodetectors, thermoelectrics, and nanocrystal ligand exchange. We also take stock of the wide range of bulk materials that can be used as soluble precursors, and discuss the work that has been done to reveal the nature of the dissolved species. This method has provided a vast toolbox of over 65 bulk precursors, which can be utilized to develop new routes to functional chalcogenide materials. Future studies in this area should work toward a better understanding of the mechanisms involved in the dissolution and recovery of bulk materials, as well as broadening the scope of soluble precursors and recoverable functional materials for innovative applications.

Capsule physics comparison of different ablators for NIF implosion designs

NASA Astrophysics Data System (ADS)

Clark, Daniel; Kritcher, Andrea; Yi, Austin; Zylstra, Alex; Haan, Steven; Ralph, Joseph; Weber, Christopher

2017-10-01

Indirect drive implosion experiments on the Naitonal Ignition Facility (NIF) have now tested three different ablator materials: glow discharge polymer (GDP) plastic, high density carbon (HDC), and beryllium. How do these different ablator choices compare in current and future implosion experiments on NIF? What are the relative advantages and disadvantages of each? This talk compares these different ablator options in capsule-only simulations of current NIF experiments and proposed future designs. The simulations compare the impact of the capsule fill tube, support tent, and interface surface roughness for each case, as well as all perturbations in combination. According to the simulations, each ablator is impacted by the various perturbation sources differently, and each material poses unique challenges in the pursuit of ignition. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Micro/nano composited tungsten material and its high thermal loading behavior

NASA Astrophysics Data System (ADS)

Fan, Jinglian; Han, Yong; Li, Pengfei; Sun, Zhiyu; Zhou, Qiang

2014-12-01

Tungsten (W) is considered as promising candidate material for plasma facing components (PFCs) in future fusion reactors attributing to its many excellent properties. Current commercial pure tungsten material in accordance with the ITER specification can well fulfil the performance requirements, however, it has defects such as coarse grains, high ductile-brittle transition temperature (DBTT) and relatively low recrystallization temperature compared with its using temperature, which cannot meet the harsh wall loading requirement of future fusion reactor. Grain refinement has been reported to be effective in improving the thermophysical and mechanical properties of W. In this work, rare earth oxide (Y2O3/La2O3) and carbides (TiC/ZrC) were used as dispersion phases to refine W grains, and micro/nano composite technology with a process of "sol gel - heterogeneous precipitation - spray drying - hydrogen reduction - ordinary consolidation sintering" was invented to introduce these second-phase particles uniformly dispersed into W grains and grain-boundaries. Via this technology, fine-grain W materials with near-full density and relatively high mechanical properties compared with traditional pure W material were manufactured. Preliminary transient high-heat flux tests were performed to evaluate the thermal response under plasma disruption conditions, and the results show that the W materials prepared by micro/nano composite technology can endure high-heat flux of 200 MW/m2 (5 ms).

An ultraviolet photodetector fabricated from WO₃ nanodiscs/reduced graphene oxide composite material.

PubMed

Shao, Dali; Yu, Mingpeng; Lian, Jie; Sawyer, Shayla

2013-07-26

A high sensitivity, fast ultraviolet (UV) photodetector was fabricated from WO₃ nanodiscs (NDs)/reduced graphene oxide (RGO) composite material. The WO₃ NDs/reduced GO composite material was synthesized using a facile three-step synthesis procedure. First, the Na₂WO₄/GO precursor was synthesized by homogeneous precipitation. Second, the Na₂WO₄/GO precursor was transformed into Na₂WO₄/GO composites by acidification. Finally, the Na₂WO₄/GO composites were reduced to WO₃ NDs/RGO via a hydrothermal reduction process. The UV photodetector showed a fast transient response and high responsivity, which are attributed to the improved carrier transport and collection efficiency through graphene. The excellent material properties of the WO₃ NDs/RGO composite demonstrated in this work may open up new possibilities for using WO₃ NDs/RGO for future optoelectronic applications.

Determination of Interlaminar Toughness of IM7/977-2 Composites at Temperature Extremes and Different Thicknesses

NASA Technical Reports Server (NTRS)

Johnson, W. S.; Pavlick, M. M.; Oliver, M. S.

2005-01-01

Composite materials are being used in the aerospace industry as a means of reducing vehicle weight. In particular, polymer matrix composites (PMC) are good candidates due to their high strength-to-weight and high stiffness-to-weight ratios. Future reusable space launch vehicles and space exploration structures will need advanced light weight composites in order to minimize vehicle weight while demonstrating robustness and durability, guaranteeing high factors of safety. In particular, the implementation of composite cryogenic propellant fuel tanks (cryotanks) for future reusable launch vehicles (RLVs) could greatly reduce the vehicle's weight versus identically sized cryotanks constructed of metallic materials. One candidate composite material for future cryotank designs is IM7/977-2, which is a graphite/epoxy system. A successful candidate must demonstrate reasonable structural properties over a wide range of temperatures. Since the matrix material is normally the weak link in the composite, tests that emphasize matrix-dominated behavior need to be conducted. Therefore, the objective of this work is to determine the mode I interlaminar fracture toughness of "unidirectional" 8-ply and 16-ply IM7/977-2 through experimental testing. Tests were performed at -196 degrees Celsius (-320 degrees Fahrenheit), 22 degrees Celsius (72 degrees Fahrenheit), 93 degrees Celsius (200 degrees Fahrenheit) and 160 degrees C (320 degrees Fahrenheit). Low temperature testing was completed while the specimen was submerged in a liquid nitrogen bath. High temperature testing was completed in a temperature-controlled oven.

Advanced 3D Characterization and Reconstruction of Reactor Materials FY16 Final Report

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

Fromm, Bradley; Hauch, Benjamin; Sridharan, Kumar

2016-12-01

A coordinated effort to link advanced materials characterization methods and computational modeling approaches is critical to future success for understanding and predicting the behavior of reactor materials that operate at extreme conditions. The difficulty and expense of working with nuclear materials have inhibited the use of modern characterization techniques on this class of materials. Likewise, mesoscale simulation efforts have been impeded due to insufficient experimental data necessary for initialization and validation of the computer models. The objective of this research is to develop methods to integrate advanced materials characterization techniques developed for reactor materials with state-of-the-art mesoscale modeling and simulationmore » tools. Research to develop broad-ion beam sample preparation, high-resolution electron backscatter diffraction, and digital microstructure reconstruction techniques; and methods for integration of these techniques into mesoscale modeling tools are detailed. Results for both irradiated and un-irradiated reactor materials are presented for FY14 - FY16 and final remarks are provided.« less

Work Function Engineering of Graphene

PubMed Central

Garg, Rajni; Dutta, Naba K.; Roy Choudhury, Namita

2014-01-01

Graphene is a two dimensional one atom thick allotrope of carbon that displays unusual crystal structure, electronic characteristics, charge transport behavior, optical clarity, physical & mechanical properties, thermal conductivity and much more that is yet to be discovered. Consequently, it has generated unprecedented excitement in the scientific community; and is of great interest to wide ranging industries including semiconductor, optoelectronics and printed electronics. Graphene is considered to be a next-generation conducting material with a remarkable band-gap structure, and has the potential to replace traditional electrode materials in optoelectronic devices. It has also been identified as one of the most promising materials for post-silicon electronics. For many such applications, modulation of the electrical and optical properties, together with tuning the band gap and the resulting work function of zero band gap graphene are critical in achieving the desired properties and outcome. In understanding the importance, a number of strategies including various functionalization, doping and hybridization have recently been identified and explored to successfully alter the work function of graphene. In this review we primarily highlight the different ways of surface modification, which have been used to specifically modify the band gap of graphene and its work function. This article focuses on the most recent perspectives, current trends and gives some indication of future challenges and possibilities. PMID:28344223

Work Function Engineering of Graphene.

PubMed

Garg, Rajni; Dutta, Naba K; Choudhury, Namita Roy

2014-04-03

Graphene is a two dimensional one atom thick allotrope of carbon that displays unusual crystal structure, electronic characteristics, charge transport behavior, optical clarity, physical & mechanical properties, thermal conductivity and much more that is yet to be discovered. Consequently, it has generated unprecedented excitement in the scientific community; and is of great interest to wide ranging industries including semiconductor, optoelectronics and printed electronics. Graphene is considered to be a next-generation conducting material with a remarkable band-gap structure, and has the potential to replace traditional electrode materials in optoelectronic devices. It has also been identified as one of the most promising materials for post-silicon electronics. For many such applications, modulation of the electrical and optical properties, together with tuning the band gap and the resulting work function of zero band gap graphene are critical in achieving the desired properties and outcome. In understanding the importance, a number of strategies including various functionalization, doping and hybridization have recently been identified and explored to successfully alter the work function of graphene. In this review we primarily highlight the different ways of surface modification, which have been used to specifically modify the band gap of graphene and its work function. This article focuses on the most recent perspectives, current trends and gives some indication of future challenges and possibilities.

Parametric estimation for reinforced concrete relief shelter for Aceh cases

NASA Astrophysics Data System (ADS)

Atthaillah; Saputra, Eri; Iqbal, Muhammad

2018-05-01

This paper was a work in progress (WIP) to discover a rapid parametric framework for post-disaster permanent shelter’s materials estimation. The intended shelters were reinforced concrete construction with bricks as its wall. Inevitably, in post-disaster cases, design variations were needed to help suited victims condition. It seemed impossible to satisfy a beneficiary with a satisfactory design utilizing the conventional method. This study offered a parametric framework to overcome slow construction-materials estimation issue against design variations. Further, this work integrated parametric tool, which was Grasshopper to establish algorithms that simultaneously model, visualize, calculate and write the calculated data to a spreadsheet in a real-time. Some customized Grasshopper components were created using GHPython scripting for a more optimized algorithm. The result from this study was a partial framework that successfully performed modeling, visualization, calculation and writing the calculated data simultaneously. It meant design alterations did not escalate time needed for modeling, visualization, and material estimation. Further, the future development of the parametric framework will be made open source.

Indentation-Induced Shear Band Formation in Thin-Film Multilayers

NASA Astrophysics Data System (ADS)

Bigelow, Shannon; Shen, Yu-Lin

2017-08-01

We report an exploratory investigation into the cause of shear band formation in multilayer thin-films subject to nanoindentation. The material system considered here is composed of alternating aluminum (Al) and silicon carbide (SiC) nanolayers, atop a silicon (Si) substrate. Finite element models are developed in an attempt to reproduce the shear banding phenomenon observed experimentally. By introducing strain softening into the material model for the hard SiC layers, shear bands can be seen to emerge from the indentation site in the finite element analysis. Broad implications, along with possible directions for future work, are discussed.

KSC-97PC1462

NASA Image and Video Library

1997-09-15

United States Microgravity Payload-4 (USMP-4) experiments are prepared to be flown on Space Shuttle mission STS-87 in the Space Station Processing Facility at Kennedy Space Center (KSC). A technician is working on the Advanced Automated Directional Solidification Furnace (AADSF), which will be used by researchers to study the solidification of semiconductor materials in microgravity. Scientists will be able to better understand how microgravity influences the solidification process of these materials and develop better methods for controlling that process during future Space flights and Earth-based production. All STS-87 experiments are scheduled for launch on Nov. 19 from KSC

Blood compatibility--a perspective.

PubMed

Ratner, B D

2000-01-01

This perspective on blood- materials interactions is intended to introduce the set of papers stemming from the symposium, "Devices and Diagnostics in Contact with Blood: Issues in Blood Compatibility at the Close of the 20th Century," organized on August 4-6, 1999 at the University of Washington by the University of Washington Engineered Biomaterials (UWEB) Engineering Research Center. This article outlines some of the history of blood contacting materials, overviews the work that has originated at the University of Washington over the past 28 years, speculates on the origins of the controversies on blood compatibility and considers the issues that should be addressed in future studies.

Nuclear energy.

PubMed

Grandin, Karl; Jagers, Peter; Kullander, Sven

2010-01-01

Nuclear energy can play a role in carbon free production of electrical energy, thus making it interesting for tomorrow's energy mix. However, several issues have to be addressed. In fission technology, the design of so-called fourth generation reactors show great promise, in particular in addressing materials efficiency and safety issues. If successfully developed, such reactors may have an important and sustainable part in future energy production. Working fusion reactors may be even more materials efficient and environmental friendly, but also need more development and research. The roadmap for development of fourth generation fission and fusion reactors, therefore, asks for attention and research in these fields must be strengthened.

Crystal growth in a low gravity environment

NASA Technical Reports Server (NTRS)

Carruthers, J. R.

1977-01-01

Crystal growth in microgravity possesses several distinct technological advantages over earth-bound processes; containerless handling and reduction of density gradient driven as well as sedimentation flows. Experiments performed in space to date have been basically reproductions of processes currently used on earth and the results have clarified our understanding of crystal growth dynamics. In addition, both unresolved problems and areas requiring further study on earth have been identified. Future work in space processing of materials must address these areas of study as soon as possible if the full potential of a space environment to develop new techniques and materials is to be realized.

NASA International Environmental Partnerships

NASA Technical Reports Server (NTRS)

Lewis, Pattie; Valek, Susan

2010-01-01

For nearly five decades, the National Aeronautics and Space Administration (NASA) has been preeminent in space exploration. NASA has landed Americans on the moon, robotic rovers on Mars, and led cooperative scientific endeavors among nations aboard the International Space Station. But as Earth's population increases, the environment is subject to increasing challenges and requires more efficient use of resources. International partnerships give NASA the opportunity to share its scientific and engineering expertise. They also enable NASA to stay aware of continually changing international environmental regulations and global markets for materials that NASA uses to accomplish its mission. Through international partnerships, NASA and this nation have taken the opportunity to look globally for solutions to challenges we face here on Earth. Working with other nations provides NASA with collaborative opportunities with the global science/engineering community to explore ways in which to protect our natural resources, conserve energy, reduce the use of hazardous materials in space and earthly applications, and reduce greenhouse gases that potentially affect all of Earth's inhabitants. NASA is working with an ever-expanding list of international partners including the European Union, the European Space Agency and, especially, the nation of Portugal. Our common goal is to foster a sustainable future in which partners continue to explore the universe while protecting our home planet's resources for future generations. This brochure highlights past, current, and future initiatives in several important areas of international collaboration that can bring environmental, economic, and other benefits to NASA and the wider international space community.

Ultrasonic High-Temperature Sensors: Past Experiments and Prospects for Future Use

NASA Astrophysics Data System (ADS)

Laurie, M.; Magallon, D.; Rempe, J.; Wilkins, C.; Pierre, J.; Marquié, C.; Eymery, S.; Morice, R.

2010-09-01

Ultrasonic thermometry sensors (UTS) have been intensively studied in the past to measure temperatures from 2080 K to 3380 K. This sensor, which uses the temperature dependence of the acoustic velocity in materials, was developed for experiments in extreme environments. Its major advantages, which are (a) capability of measuring a temperature profile from multiple sensors on a single probe and (b) measurement near the sensor material melting point, can be of great interest when dealing with on-line monitoring of high-temperature safety tests. Ultrasonic techniques were successfully applied in several severe accident related experiments. With new developments of alternative materials, this instrument may be used in a wide range of experimental areas where robustness and compactness are required. Long-term irradiation experiments of nuclear fuel to extremely high burn-ups could benefit from this previous experience. After an overview of UTS technology, this article summarizes experimental work performed to improve the reliability of these sensors. The various designs, advantages, and drawbacks are outlined and future prospects for long-term high-temperature irradiation experiments are discussed.

Guidelines for children's work in agriculture: implications for the future.

PubMed

Marlenga, Barbara; Lee, Barbara C; Pickett, William

2012-01-01

The North American Guidelines for Children's Agricultural Tasks (NAGCAT) were developed to assist parents in assigning developmentally appropriate and safe farm work to their children aged 7-16 years. Since their release in 1999, a growing body of evidence has accumulated regarding the content and application of these guidelines to populations of working children on farms. The purpose of this paper is to review the scientific and programmatic evidence about the content, efficacy, application, and uptake of NAGCAT and propose key recommendations for the future. The methods for this review included a synthesis of the peer-reviewed literature and programmatic evidence gathered from safety professionals. From the review, it is clear that the NAGCAT tractor guidelines and the manual material handling guidelines need to be updated based upon the latest empirical evidence. While NAGCAT do have the potential to prevent serious injuries to working children in the correct age range (7-16 years), the highest incidence of farm related injuries and fatalities occur to children aged 1-6 years and NAGCAT are unlikely to have any direct effect on this leading injury problem. It is also clear that NAGCAT, as a voluntary educational strategy, is not sufficient by itself to protect children working on farms. Uptake of NAGCAT has been sporadic, despite being geographically widespread and has depended, almost solely, on a few interested and committed professionals. Key recommendations for the future are provided based upon this review.

A new international agenda for astronomy education research

NASA Astrophysics Data System (ADS)

Bretones, Paulo Sergio

2015-08-01

A great deal can be learned about astronomy education research by conducting comprehensive summary reviews of scholarly production revealing trends and gaps in the area. Motivated by the recent IAU Commission Reform, we are proposing projects related to the Commission 46 and more specifically to the Working Group on Theory and Methods in Astronomy Education. The goal of this work is to present a new international agenda for research on astronomy education. In a general way we intend to encourage efforts to increase the scholarly production in the area and encourage surveys of what has been published in several regions of the globe. These surveys refer to the various forms of production, published in theses dissertations, conference proceedings and journal articles. We believe that there exists considerable scholarly effort around the world, but that much of it is “hidden” and systematic surveys need to be conducted internationally to collect and synthesize this material to guide future work. Much of the work in these venues is certainly not known by researchers in Astronomy, not only because they belong to a different area of theoretical and methodological framework, but also because they are related to teaching in Physics and general sciences, rather than Astronomy specifically. This kind of research is largely invisible because it occurs in very specific different contexts of production, culture, curriculum, materials and application in schools with local teachers and the general public. To improve the present situation, international events are proposed in various continents seeking to encourage surveys of already published materials, their studies and seeking also new key lines of research. As concrete examples, surveys, scholarly reviews and studies conducted in Brazil and other countries are shown. We believe that such actions should raise the visibility of authors and institutions and enable studies of state-of-the-art showing trends and gaps, allowing future developments and collaborations.

Double Shock Experiments Performed at -55°C on LX-17 with Reactive Flow Modeling to Understand the Reacted Equation of State

NASA Astrophysics Data System (ADS)

Dehaven, Martin R.; Vandersall, Kevin S.; Strickland, Shawn L.; Fried, Laurence E.; Tarver, Craig M.

2017-06-01

Experiments were performed at -55°C to measure the reacted state of LX-17 (92.5% TATB and 7.5% Kel-F by weight) using a double shock technique using two flyer materials (with known properties) mounted on a projectile that send an initial shock through the material close to the Chapman-Jouguet (CJ) state followed by a second shock at a higher magnitude into the detonated material. Information on the reacted state is obtained by measuring the relative timing and magnitude of the first and second shock waves. The LX-17 detonation reaction zone profiles plus the arrival times and amplitudes of reflected shocks in LX-17 detonation reaction products were measured using Photonic Doppler Velocimetry (PDV) probes and an aluminum foil coated LiF window. A discussion of this work will include a comparison to prior work at ambient temperature, the experimental parameters, velocimetry profiles, data interpretation, reactive CHEETAH and Ignition and Growth modeling, as well as detail on possible future experiments. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Teens Working: Turning Earning into Learning. Facilitator Guide [and] Critical Workplace Issues [and] Student Guide.

ERIC Educational Resources Information Center

Northwest Regional Educational Lab., Portland, OR. Education, Career, and Community Program.

These guides are part of a toolkit designed to help young people make connections between the jobs they now hold, the classes they are taking, and the goals they may have for the near and distant future. The guides contain a variety of materials and activities appropriate for all skill levels. The activities in the student guide are grounded in…

Improved detectivity of pyroelectric detectors

NASA Technical Reports Server (NTRS)

Marshall, D. E.; Gelpey, J. C.; Marciniec, J. W.; Chiang, A. M.; Maciolek, R. B.

1978-01-01

High detectivity single-element SBN pyroelectric detectors were fabricated. The theory and technology developments related to improved detector performance were identified and formulated. Improved methods of material characterization, thinning, mounting, blackening and amplifier matching are discussed. Detectors with detectivities of 1.3 x 10 to the 9th power square root of Hz/watt at 1 Hz are reported. Factors limiting performance and recommendations for future work are discussed.

Advanced technology composite aircraft structures

NASA Technical Reports Server (NTRS)

Ilcewicz, Larry B.; Walker, Thomas H.

1991-01-01

Work performed during the 25th month on NAS1-18889, Advanced Technology Composite Aircraft Structures, is summarized. The main objective of this program is to develop an integrated technology and demonstrate a confidence level that permits the cost- and weight-effective use of advanced composite materials in primary structures of future aircraft with the emphasis on pressurized fuselages. The period from 1-31 May 1991 is covered.

CORNER OF SUBPILE ROOM: NORTH AND EAST SIDES. STEEL OUTER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CORNER OF SUBPILE ROOM: NORTH AND EAST SIDES. STEEL OUTER SHELL HAS BEEN AFFIXED. SIGN SAYS "HERRICK IRON WORKS STEEL, OAKLAND, CALIFORNIA." NOTE CONDUIT FOR FUTURE INSTRUMENTATION. TOP OF STEEL CASE WILL BE LEVEL WITH BASEMENT CEILING. CAMERA FACES SOUTHEAST. INL NEGATIVE NO. 734. Unknown Photographer, 10/6/1950 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

An Experiment in Structural Analysis of the Value Orientations of the Parents of Preschoolers

ERIC Educational Resources Information Center

Sobkin, V. S.; Marich, E. M.

2004-01-01

The present article is a continuation of a study of the life values and fears regarding their future on the part of parents of children of older preschool age. The raw material was obtained by questionnaire surveying 941 parents (334 fathers and 607 mothers) whose children were going to kindergarten. In this work the authors attempted to show the…

Materials characterization activities for %E2%80%9CTake Our Sons&Daughters to Work Day%E2%80%9D 2013.

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

Mowry, Curtis Dale; Pimentel, Adam S.; Sparks, Elizabeth Schares

We created interactive demonstration activities for Take Our Daughters&Sons to Work Day (TODSTWD) 2013 in order to promote general interest in chemistry and also generate awareness of the type of work our laboratories can perform. %E2%80%9CCurious about Mars Rover Curiosity?%E2%80%9D performed an elemental analysis on rocks brought to our lab using the same technique utilized on the planet Mars by the NASA robotic explorer Curiosity. %E2%80%9CFood is Chemistry?%E2%80%9D utilized a mass spectrometer to measure, in seconds, each participant's breath in order to identify the food item consumed for the activity. A total of over 130 children participated in these activitiesmore » over a 3 hour block, and feedback was positive. This document reports the materials (including handouts), experimental procedures, and lessons learned so that future demonstrations can benefit from the baseline work performed. We also present example results used to prepare the Food activity and example results collected during the Curiosity demo.« less

Quasi-one dimensional (Q1D) nanostructures: Synthesis, integration and device application

NASA Astrophysics Data System (ADS)

Chien, Chung-Jen

Quasi-one-dimensional (Q1D) nanostructures such as nanotubes and nanowires have been widely regarded as the potential building blocks for nanoscale electronic, optoelectronic and sensing devices. In this work, the content can be divided into three categories: Nano-material synthesis and characterizations, alignment and integration, physical properties and application. The dissertation consists of seven chapters as following. Chapter 1 will give an introduction to low dimensional nano-materials. Chapter 2 explains the mechanism how Q1D nanostructure grows. Chapter 3 describes the methods how we horizontally and vertically align the Q1D nanostructure. Chapter 4 and 5 are the electrical and optical device characterization respectively. Chapter 6 demonstrates the integration of Q1D nanostructures and the device application. The last chapter will discuss the future work and conclusion of the thesis.

Physics and Process Modeling (PPM) and Other Propulsion R and T. Volume 1; Materials Processing, Characterization, and Modeling; Lifting Models

NASA Technical Reports Server (NTRS)

1997-01-01

This CP contains the extended abstracts and presentation figures of 36 papers presented at the PPM and Other Propulsion R&T Conference. The focus of the research described in these presentations is on materials and structures technologies that are parts of the various projects within the NASA Aeronautics Propulsion Systems Research and Technology Base Program. These projects include Physics and Process Modeling; Smart, Green Engine; Fast, Quiet Engine; High Temperature Engine Materials Program; and Hybrid Hyperspeed Propulsion. Also presented were research results from the Rotorcraft Systems Program and work supported by the NASA Lewis Director's Discretionary Fund. Authors from NASA Lewis Research Center, industry, and universities conducted research in the following areas: material processing, material characterization, modeling, life, applied life models, design techniques, vibration control, mechanical components, and tribology. Key issues, research accomplishments, and future directions are summarized in this publication.

EUV lithography using water-developable resist material derived from biomass

NASA Astrophysics Data System (ADS)

Takei, Satoshi; Oshima, Akihiro; Oyama, Tomoko G.; Ichikawa, Takumi; Sekiguchi, Atsushi; Kashiwakura, Miki; Kozawa, Takahiro; Tagawa, Seiichi

2013-03-01

A water-developable resist material which had specific desired properties such as high sensitivity of 5.0 μC/cm2, thermal stability of 160 °C, suitable calculated linear absorption coefficients of 13.5 nm, and acceptable CF4 etch selectivity was proposed using EB lithography for EUV lithography. A water developable resist material derived from biomass is expected for non-petroleum resources, environmental affair, safety, easiness of handling, and health of the working people, instead of the common developable process of trimethylphenylammonium hydroxide. 100 nm line and 400 nm space patterning images with exposure dose of 5.0 μC/cm2 were provided by specific process conditions of EB lithography. The developed trehalose derivatives with hydroxyl groups and EB sensitive groups in the water-developable resist material derived from biomass were applicable to future development of high-sensitive and resolution negative type of water-developable resist material as a novel chemical design.

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

Long-Term Lunar Radiation Degradation Effects on Materials

NASA Technical Reports Server (NTRS)

Rojdev, Kristina; ORourke, Mary Jane; Koontz, Steve; Alred, John; Hill, Charles; Devivar, Rodrigo; Morera-Felix, Shakira; Atwell, William; Nutt, Steve; Sabbann, Leslie

2010-01-01

The National Aeronautics and Space Administration (NASA) is focused on developing technologies for extending human presence beyond low Earth orbit. These technologies are to advance the state-of-the-art and provide for longer duration missions outside the protection of Earth's magnetosphere. One technology of great interest for large structures is advanced composite materials, due to their weight and cost savings, enhanced radiation protection for the crew, and potential for performance improvements when compared with existing metals. However, these materials have not been characterized for the interplanetary space environment, and particularly the effects of high energy radiation, which is known to cause damage to polymeric materials. Therefore, a study focusing on a lunar habitation element was undertaken to investigate the integrity of potential structural composite materials after exposure to a long-term lunar radiation environment. An overview of the study results are presented, along with a discussion of recommended future work.

Germanium Based Field-Effect Transistors: Challenges and Opportunities

PubMed Central

Goley, Patrick S.; Hudait, Mantu K.

2014-01-01

The performance of strained silicon (Si) as the channel material for today’s metal-oxide-semiconductor field-effect transistors may be reaching a plateau. New channel materials with high carrier mobility are being investigated as alternatives and have the potential to unlock an era of ultra-low-power and high-speed microelectronic devices. Chief among these new materials is germanium (Ge). This work reviews the two major remaining challenges that Ge based devices must overcome if they are to replace Si as the channel material, namely, heterogeneous integration of Ge on Si substrates, and developing a suitable gate stack. Next, Ge is compared to compound III-V materials in terms of p-channel device performance to review how it became the first choice for PMOS devices. Different Ge device architectures, including surface channel and quantum well configurations, are reviewed. Finally, state-of-the-art Ge device results and future prospects are also discussed. PMID:28788569

Biodegradable Magnesium Alloys Developed as Bone Repair Materials: A Review

PubMed Central

Liu, Chen; Ren, Zheng; Xu, Yongdong; Pang, Song; Zhao, Xinbing

2018-01-01

Bone repair materials are rapidly becoming a hot topic in the field of biomedical materials due to being an important means of repairing human bony deficiencies and replacing hard tissue. Magnesium (Mg) alloys are potentially biocompatible, osteoconductive, and biodegradable metallic materials that can be used in bone repair due to their in situ degradation in the body, mechanical properties similar to those of bones, and ability to positively stimulate the formation of new bones. However, rapid degradation of these materials in physiological environments may lead to gas cavities, hemolysis, and osteolysis and thus, hinder their clinical orthopedic applications. This paper reviews recent work on the use of Mg alloy implants in bone repair. Research to date on alloy design, surface modification, and biological performance of Mg alloys is comprehensively summarized. Future challenges for and developments in biomedical Mg alloys for use in bone repair are also discussed. PMID:29725492

Fiber-Embedded Metallic Materials: From Sensing towards Nervous Behavior

PubMed Central

Saheb, Nouari; Mekid, Samir

2015-01-01

Embedding of fibers in materials has attracted serious attention from researchers and has become a new research trend. Such material structures are usually termed “smart” or more recently “nervous”. Materials can have the capability of sensing and responding to the surrounding environmental stimulus, in the former, and the capability of feeling multiple structural and external stimuli, while feeding information back to a controller for appropriate real-time action, in the latter. In this paper, embeddable fibers, embedding processes, and behavior of fiber-embedded metallic materials are reviewed. Particular emphasis has been given to embedding fiber Bragg grating (FBG) array sensors and piezo wires, because of their high potential to be used in nervous materials for structural health monitoring. Ultrasonic consolidation and laser-based layered manufacturing processes are discussed in detail because of their high potential to integrate fibers without disruption. In addition, current challenges associated with embedding fibers in metallic materials are highlighted and recommendations for future research work are set. PMID:28793689

The rise of organic electrode materials for energy storage.

PubMed

Schon, Tyler B; McAllister, Bryony T; Li, Peng-Fei; Seferos, Dwight S

2016-11-07

Organic electrode materials are very attractive for electrochemical energy storage devices because they can be flexible, lightweight, low cost, benign to the environment, and used in a variety of device architectures. They are not mere alternatives to more traditional energy storage materials, rather, they have the potential to lead to disruptive technologies. Although organic electrode materials for energy storage have progressed in recent years, there are still significant challenges to overcome before reaching large-scale commercialization. This review provides an overview of energy storage systems as a whole, the metrics that are used to quantify the performance of electrodes, recent strategies that have been investigated to overcome the challenges associated with organic electrode materials, and the use of computational chemistry to design and study new materials and their properties. Design strategies are examined to overcome issues with capacity/capacitance, device voltage, rate capability, and cycling stability in order to guide future work in the area. The use of low cost materials is highlighted as a direction towards commercial realization.

Design of intelligent composites with life-cycle health management capabilities

NASA Astrophysics Data System (ADS)

Rosania, Colleen L.; Larrosa, Cecilia C.; Chang, Fu-Kuo

2015-03-01

Use of carbon fiber reinforced polymers (CFRPs) presents challenges because of their complex manufacturing processes and different damage mechanics in relation to legacy metal materials. New monitoring methods for manufacturing, quality verification, damage estimation, and prognosis are needed to use CFRPs safely and efficiently. This work evaluates the development of intelligent composite materials using integrated piezoelectric sensors to monitor the material during cure and throughout service life. These sensors are used to propagate ultrasonic waves through the structure for health monitoring. During manufacturing, data is collected at different stages during the cure cycle, detecting the changing material properties during cure and verifying quality and degree of cure. The same sensors can then be used with previously developed techniques to perform damage detection, such as impact detection and matrix crack density estimation. Real-time damage estimation can be combined with prognostic models to predict future propagation of damage in the material. In this work experimental results will be presented from composite coupons with embedded piezoelectric sensors. Cure monitoring and damage detection results derived from analysis of the ultrasonic sensor signal will be shown. Sensitive signal parameters to the different stimuli in both the time and frequency domains will be explored for this analysis. From these results, use of the same sensor networks from manufacturing throughout the life of the composite material will demonstrate the full life-cycle monitoring capability of these intelligent materials.

State-of-the-art review of the applications of nanotechnology in pavement materials

NASA Astrophysics Data System (ADS)

Castillo, Luis, Jr.

The use of nanotechnology in pavement materials is one main area that shows great promise and has the potential to change commonly used materials. This will develop more effective solutions to achieve the desired performance. The overall objective of this work is to present a state-of-the-art literature review of nano-science-based principles to improve the performance and, ultimately, the life cycle of transportation construction materials. This work will be organized into two different parts. The first part will consist of six sections: applications of nanotechnology in concrete pavements, applications of nanotechnology in asphalt pavement, application of nanotechnology in general soils, cost-benefit analysis, challenges, and trends to the future. In addition, a current practice review was performed from a literature review that included a questionnaire of the knowledge and opinion about nanotechnology, which included students, general contractors, teachers, engineers, and architects. The second part will deal with the advancement of the application of nanotechnology in pavement materials for different developed countries. Because nanotechnology is relatively a young field in pavement materials, limited research has been conducted in North America, Europe, and Asia. A comparison of the advancement of nano-science-based principles, as applied to the performance and life cycle of transportation materials, for the three continents will be carried out in a summarized manner.

FY2016 Propulsion Materials Annual Progress Report

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

None, None

The Propulsion Materials Program actively supports the energy security and reduction of greenhouse emissions goals of VTO by investigating and identifying the materials properties that are most essential for continued development of cost-effective, highly efficient, and environmentally friendly next-generation heavy and light-duty powertrains. The technical approaches available to enhance propulsion systems focus on improvements in both vehicle efficiency and fuel substitution, both of which must overcome the performance limitations of the materials currently in use. Propulsion Materials Program activities work with national laboratories, industry experts, and VTO powertrain systems (e.g., Advanced Combustion Engines and Fuels) teams to develop strategies thatmore » overcome materials limitations in future powertrain performance. The technical maturity of the portfolio of funded projects ranges from basic science to subsystem prototype validation. Projects within a Propulsion Materials Program activity address materials concerns that directly impact critical technology barriers within each of the above programs, including barriers that impact fuel efficiency, thermal management, emissions reduction, improved reliability, and reduced manufacturing costs. The program engages only the barriers that result from material property limitations and represent fundamental, high-risk materials issues.« less

High Temperature Integrated Thermoelectric Ststem and Materials

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

Mike S. H. Chu

2011-06-06

The final goal of this project is to produce, by the end of Phase II, an all ceramic high temperature thermoelectric module. Such a module design integrates oxide ceramic n-type, oxide ceramic p-type materials as thermoelectric legs and oxide ceramic conductive material as metalizing connection between n-type and p-type legs. The benefits of this all ceramic module are that it can function at higher temperatures (> 700 C), it is mechanically and functionally more reliable and it can be scaled up to production at lower cost. With this all ceramic module, millions of dollars in savings or in new opportunitiesmore » recovering waste heat from high temperature processes could be made available. A very attractive application will be to convert exhaust heat from a vehicle to reusable electric energy by a thermoelectric generator (TEG). Phase I activities were focused on evaluating potential n-type and p-type oxide compositions as the thermoelectric legs. More than 40 oxide ceramic powder compositions were made and studied in the laboratory. The compositions were divided into 6 groups representing different material systems. Basic ceramic properties and thermoelectric properties of discs sintered from these powders were measured. Powders with different particles sizes were made to evaluate the effects of particle size reduction on thermoelectric properties. Several powders were submitted to a leading thermoelectric company for complete thermoelectric evaluation. Initial evaluation showed that when samples were sintered by conventional method, they had reasonable values of Seebeck coefficient but very low values of electrical conductivity. Therefore, their power factors (PF) and figure of merits (ZT) were too low to be useful for high temperature thermoelectric applications. An unconventional sintering method, Spark Plasma Sintering (SPS) was determined to produce better thermoelectric properties. Particle size reduction of powders also was found to have some positive benefits. Two composition systems, specifically 1.0 SrO - 0.8 x 1.03 TiO2 - 0.2 x 1.03 NbO2.5 and 0.97 TiO2 - 0.03 NbO2.5, have been identified as good base line compositions for n-type thermoelectric compositions in future module design. Tests of these materials at an outside company were promising using that company's processing and material expertise. There was no unique p-type thermoelectric compositions identified in phase I work other than several current cobaltite materials. Ca3Co4O9 will be the primary p-type material for the future module design until alternative materials are developed. BaTiO3 and rare earth titanate based dielectric compositions show both p-type and n-type behavior even though their electrical conductivities were very low. Further research and development of these materials for thermoelectric applications is planned in the future. A preliminary modeling and optimization of a thermoelectric generator (TEG) that uses the n-type 1.0 SrO - 1.03 x 0.8 TiO2 - 1.03 x 0.2 NbO2.5 was performed. Future work will combine development of ceramic powders and manufacturing expertise at TAM, development of SPS at TAM or a partner organization, and thermoelectric material/module testing, modeling, optimization, production at several partner organizations.« less

Brexit and dentistry.

PubMed

Sinclair, E; Stagnell, S; Shah, S

2016-05-27

On 23 June 2016, eligible UK voters will be asked to decide whether to vote in the EU referendum. The EU impacts on our daily lives in more ways than many people realise. Dentistry is affected by EU legislation. Examples include the movement of dental professionals, the import of dental equipment and materials, as well as health and safety legislation. Many more EU dentists and DCPs come to the UK to work than vice versa. These numbers have increased markedly since 2004. The result of the vote may affect how dentistry operates in the UK in future years. In addition, a vote to stay would not necessarily prevent change. There are attempts underway to increase the ease by which professionals can work in other member states, especially on a temporary basis. This too is likely affect dentistry at some point. Workforce planners and policy makers should factor in the impact of the EU in future dental policy.

DNDO Report

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

Liegey, Lauren Rene; Wilcox, Trevor; Mckinney, Gregg Walter

2015-08-07

My internship program was the Domestic Nuclear Detection Office Summer Internship Program. I worked at Los Alamos National Laboratory with Trevor A. Wilcox and Gregg W. McKinney in the NEN-5 group. My project title was “MCNP Physical Model Interoperability & Validation”. The goal of my project was to write a program to predict the solar modulation parameter for dates in the future and then implement it into MCNP6. This update to MCNP6 can be used to calculate the background more precisely, which is an important factor in being able to detect Special Nuclear Material. We will share our work inmore » a published American Nuclear Society (ANS) paper, an ANS presentation, and a LANL student poster session. Through this project, I gained skills in programming, computing, and using MCNP. I also gained experience that will help me decide on a career or perhaps obtain employment in the future.« less

NDE of Fiber Reinforced Foam Composite Structures for Future Aerospace Vehicles

NASA Technical Reports Server (NTRS)

Walker, james; Roth, Don; Hopkins, Dale

2010-01-01

This slide presentation reviews the complexities of non-destructive evaluation (NDE) of fiber reinforced foam composite structures to be used for aerospace vehicles in the future.Various views of fiber reinforced foam materials are shown and described. Conventional methods of NDE for composites are reviewed such as Micro-computed X-Ray Tomography, Thermography, Shearography, and Phased Array Ultrasonics (PAUT). These meth0ods appear to work well on the face sheet and face sheet ot core bond, they do not provide adequate coverage for the webs. There is a need for additional methods that will examine the webs and web to foam core bond.

Printing nature: Unraveling the role of nacre's mineral bridges.

PubMed

Gu, Grace X; Libonati, Flavia; Wettermark, Susan D; Buehler, Markus J

2017-12-01

Creating materials with strength and toughness has been a long-sought goal. Conventional engineering materials often face a trade-off between strength and toughness, prompting researchers seeking to overcome these limitations to explore more sophisticated materials, such as composites. This paradigm shift in material design is spurred by nature, which exhibits a plethora of heterogeneous materials that offer outstanding material properties, and many natural materials are widely regarded as examples of high-performing hybrid materials. A classic example is nacre, also known as mother-of-pearl, which boasts a combination of high stiffness, strength, and fracture toughness. Various microstructural features contribute to the toughness of nacre, including mineral bridges (MBs), nano-asperities, and waviness of the constituent platelets. Recent research in biomimicry suggests that MBs contribute to the high strength and toughness observed in nacre and nacre-inspired materials. However, previous work in this area did not allow for complete control over the length scale of the bridges and had limitations on the volume fraction of mineral content. In this work, we present a systematic investigation elucidating the effects of structural parameters, such as volume fraction of mineral phase and density of MBs, on the mechanical response of nacre-inspired additive manufactured composites. Our results demonstrate that it is possible to tune the composite properties by tuning sizes and content of structural features (e.g. MBs and mineral content) in a heterogeneous material. Looking forward, this systematic approach enables materials-by-design of complex architectures to tackle demanding engineering challenges in the future. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nanotechnology Based Green Energy Conversion Devices with Multifunctional Materials at Low Temperatures.

PubMed

Lu, Yuzheng; Afzal, Muhammad; Zhu, Bin; Wang, Baoyuan; Wang, Jun; Xia, Chen

2017-07-10

Nanocomposites (integrating the nano and composite technologies) for advanced fuel cells (NANOCOFC) demonstrate the great potential to reduce the operational temperature of solid oxide fuel cell (SOFC) significantly in the low temperature (LT) range 300-600ºC. NANOCOFC has offered the development of multi-functional materials composed of semiconductor and ionic materials to meet the requirements of low temperature solid oxide fuel cell (LTSOFC) and green energy conversion devices with their unique mechanisms. This work reviews the recent developments relevant to the devices and the patents in LTSOFCs from nanotechnology perspectives that reports advances including fabrication methods, material compositions, characterization techniques and cell performances. Finally, the future scope of LTSOFC with nanotechnology and the practical applications are also discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Advances In Microwave Metamaterials

NASA Astrophysics Data System (ADS)

Wigle, James A.

2011-12-01

Metamaterials are a new area of research showing significant promise for an entirely new set of materials, and material properties. Only recently has three-fourths of the entire electromagnetic material space been made available for discoveries, research, and applications. This thesis is a culmination of microwave metamaterial research that has transpired over numerous years at the University of Colorado. New work is presented; some is complete while other work has yet to be finished. Given the significant work efforts, and potential for new and interesting results, I have included some of my partial work to be completed in the future. This thesis begins with background theory to assist readers in fully understanding the mechanisms that drove my research and results obtained. I illustrate the design and manufacture of a metamaterial that can operate within quadrants I and II of the electromagnetic material space (epsilon r > 0 and mur > 0 or epsilonr < 0 and mu r > 0, respectively). Another metamaterial design is presented for operation within quadrant III of the electromagnetic material space (epsilonr < 0 and mur < 0). Lorentz reciprocity is empirically demonstrated for a quadrant I and II metamaterial, as well as a metamaterial enhanced antenna, or meta-antenna. Using this meta-antenna I demonstrate improved gain and directivity, and illuminate how the two are not necessarily coincident in frequency. I demonstrate a meta-lens which provides a double beam pattern for a normally hemispherical antenna, which also provides a null where the antenna alone would provide a peak on boresight. The thesis also presents two related, but different, novel tests intended to be used to definitively illustrate the negative angle of refraction for indices of refraction less than zero. It will be shown how these tests can be used to determine most bulk electromagnetic material properties of the material under test, for both right handed and left handed materials, such as epsilonr, mur, deltaloss, and n. The work concluding this thesis is an attempt to derive modified Fresnel Coefficients, for which I actually believe to be incorrect. Though, in transposing I have corrected a few mistakes, and now I can no longer find the conundrum. I have included this work to illuminate the need for modified Fresnel coefficients for cases of negative indices of refraction, identifying all disparate cases requiring a new set of equations, as well as to assist others in their efforts through illumination of the potential erroneous path chosen.

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

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

NONE

1998-05-01

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

Knowledge based systems: A critical survey of major concepts, issues and techniques. Visuals

NASA Technical Reports Server (NTRS)

Dominick, Wayne D. (Editor); Kavi, Srinu

1984-01-01

This Working Paper Series entry represents a collection of presentation visuals associated with the companion report entitled, Knowledge Based Systems: A Critical Survey of Major Concepts, Issues, and Techniques, USL/DBMS NASA/RECON Working Paper Series report number DBMS.NASA/RECON-9. The objectives of the report are to: examine various techniques used to build the KBS; to examine at least one KBS in detail, i.e., a case study; to list and identify limitations and problems with the KBS; to suggest future areas of research; and to provide extensive reference materials.

Future perspectives of resin-based dental materials.

PubMed

Jandt, Klaus D; Sigusch, Bernd W

2009-08-01

This concise review and outlook paper gives a view of selected potential future developments in the area of resin-based biomaterials with an emphasis on dental composites. A selection of key publications (1 book, 35 scientific original publications and 1 website source) covering the areas nanotechnology, antimicrobial materials, stimuli responsive materials, self-repairing materials and materials for tissue engineering with direct or indirect relations and/or implications to resin-based dental materials is critically reviewed and discussed. Connections between these fields and their potential for resin-based dental materials are highlighted and put in perspective. The need to improve shrinkage properties and wear resistance is obvious for dental composites, and a vast number of attempts have been made to accomplish these aims. Future resin-based materials may be further improved in this respect if, for example nanotechnology is applied. Dental composites may, however, reach a completely new quality by utilizing new trends from materials science, such as introducing nanostructures, antimicrobial properties, stimuli responsive capabilities, the ability to promote tissue regeneration or repair of dental tissues if the composites were able to repair themselves. This paper shows selected potential future developments in the area of resin-based dental materials, gives basic and industrial researchers in dental materials science, and dental practitioners a glance into the potential future of these materials, and should stimulate discussion about needs and future developments in the area.

High-κ gate dielectrics: Current status and materials properties considerations

NASA Astrophysics Data System (ADS)

Wilk, G. D.; Wallace, R. M.; Anthony, J. M.

2001-05-01

Many materials systems are currently under consideration as potential replacements for SiO2 as the gate dielectric material for sub-0.1 μm complementary metal-oxide-semiconductor (CMOS) technology. A systematic consideration of the required properties of gate dielectrics indicates that the key guidelines for selecting an alternative gate dielectric are (a) permittivity, band gap, and band alignment to silicon, (b) thermodynamic stability, (c) film morphology, (d) interface quality, (e) compatibility with the current or expected materials to be used in processing for CMOS devices, (f) process compatibility, and (g) reliability. Many dielectrics appear favorable in some of these areas, but very few materials are promising with respect to all of these guidelines. A review of current work and literature in the area of alternate gate dielectrics is given. Based on reported results and fundamental considerations, the pseudobinary materials systems offer large flexibility and show the most promise toward successful integration into the expected processing conditions for future CMOS technologies, especially due to their tendency to form at interfaces with Si (e.g. silicates). These pseudobinary systems also thereby enable the use of other high-κ materials by serving as an interfacial high-κ layer. While work is ongoing, much research is still required, as it is clear that any material which is to replace SiO2 as the gate dielectric faces a formidable challenge. The requirements for process integration compatibility are remarkably demanding, and any serious candidates will emerge only through continued, intensive investigation.

Use of Thermoset Composite Materials in Cryogenic Tanks

NASA Astrophysics Data System (ADS)

Diaz, V.; Cardone, T.; Ramusat, G.

2014-06-01

To improve the performances of Future Expendable Launchers, one of the key aspects to be considered is the mass optimization of the cryogenic upper stage of the launcher, where a mass saving of one Kg, is directly transferred to one more Kg of payload.This optimization is inherently linked to the use of composite materials in all the structures that conforms the upper stage of the launcher.Currently, most of the upper stage structures of the operational launchers, like Ariane 5, are made in composite materials, with the exception of the cryogenic (LH2 and LOX) tanks which remain metallic.So, from a structural point of view, the next qualitative step in the development of new expendable launcher, would be the manufacturing of the upper stage cryogenic tanks in composite materials.To reach this objective important concerns mainly related to the potential for leaks and the compatibility with the LOX need to be resolved.In the frame of the FLPP (Future Launcher Preparatory Program) funded by ESA, an activity related to the use of thermoset composite material in the cryogenic tanks has been included.This paper presents a summary of the performed work which includes:* The selection and characterization of the most suitable candidate materials for the considered application* The design and analysis of a subscale demonstrator representative of the LH2 compartment* The design, manufacturing and testing of some test articles representatives of the selected design solutions* The manufacturing and testing of the selected subscale demonstrator.

Meteorites

NASA Astrophysics Data System (ADS)

Jenniskens, Peter

2015-08-01

Meteorites have long been known to offer a unique window into planetary formation processes at the time of solar system formation and into the materials that rained down on Earth at the time of the origin of life. Their material properties determine the impact hazard of Near Earth Asteroids. Some insight into how future laboratory studies of meteorites and laboratory astrophysics simulations of relevant physical processes can help address open questions in these areas and generate new astronomical observations, comes from what was learned from the recent laboratory studies of freshly fallen meteorites. The rapid recovery of Almahata Sitta (a polymict Ureilite), Sutter's Mill (a CM chondrite regolith breccia), Novato (an L6 chondrite), and Chelyabinsk (an LL5 chondrite) each were followed by the creation of a meteorite consortium, which grew to over 50 researchers in the case of Chelyabinsk. New technologies were used to probe the organic content of the meteorites as well as their magnetic signatures, isotopic abundances, trapped noble gasses, and cosmogenic radio nucleides, amongst others. This has resulted in fascinating insight into the nature of the Ureilite parent body, the likely source region of the CM chondrites in the main asteroid belt, and the collisional environment of the CM parent body. This work has encouraged follow-up in the hope of catching more unique materials. Rapid response efforts are being developed that aim to recover meteorites as pristinely as possible from falls for which the approach orbit was measured. A significant increase in the number of known approach orbits for different meteorite types will help tie meteorite types to their asteroid family source regions. Work so far suggests that future laboratory studies may recognize multiple source regions for iron-rich ordinary chondrites, for example. Hope is that these source regions will give insight into the material properties of impacting asteroids. At least some future laboratory astrophysics experiments are expected to focus on clarifying the physical conditions during small asteroid impacts such as the one responsible for the Chelyabinsk airburst and the over 1200 injured who needed medical attention.

Science in orbit: The shuttle and spacelab experience, 1981-1986

NASA Technical Reports Server (NTRS)

1988-01-01

Significant achievements across all scientific disciplines and missions for the first six years of Shuttle flights are presented. Topics covered include science on the Space Shuttle and Spacelab, living and working in space, studying materials and processes in microgravity, observing the sun and earth, space plasma physics, atmospheric science, astronony and astrophysics, and testing new technology in space. Future research aboard the Shuttle/Spacelab is also briefly mentioned.

The Chemistry of Cat Litter: Activities for High School Students to Evaluate a Commercial Product's Properties and Claims Using the Tools of Chemistry

ERIC Educational Resources Information Center

Celestino, Teresa; Marchetti, Fabio

2015-01-01

Educating future scientists and citizens is more effective if students are guided to correctly apply what they learned in school to their daily lives. This experience-based work is focused on the study of a well-known commercial product: cat litter. This material offers different starting points for a critical examination. Questions related to…

"An Experiment Is When You Try It and See if It Works": A Study of Junior High School Students' Understanding of the Construction of Scientific Knowledge.

ERIC Educational Resources Information Center

Carey, Susan; And Others

Developing a constructivist view of scientific inquiry and knowledge is considered to be important to the training of future scientists, as well as to the understanding of scientific information by all citizens. The research reported targets the junior high school grades. Curricular materials that introduce seventh graders to the constructivist…

Precision Rolled-Ink Nano-Technology; Development of a Direct Write Technique for the Fabrication of Thin Films and Conductive Elements

DTIC Science & Technology

2012-10-01

Fabrication of Thin Films and Conductive Elements Larry R. Holmes, Jr. Weapons and Materials Research Directorate, ARL...polymer composites, glass, metals, ceramics , and others. Development of the PRINT system and future work are discussed. 15. SUBJECT TERMS direct write...7 Figure 5. PRINT deposition on (left) polished aluminum sheet metal, and (right) aluminum oxide ceramic tile

X-ray Diffraction System for Advanced Materials Analysis in Research and Education

DTIC Science & Technology

2016-05-27

on education. These courses have are important because they prepare students for industry and, as they move to more research - intensive work, the...real-life experimental research experience with emphasis on nanoscale device fabrication. The course provides a strong background in devices with...institution, and will support future research initiatives based on a 5-year warranty and broad base of university funding to projects. The system is

Intelligence Community Legal Reference Book

DTIC Science & Technology

2009-01-01

NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION ...NAME(S) AND ADDRESS(ES) Office of the Director of National Intelligence,Office of General Counsel,Washington,DC,20511 8. PERFORMING ORGANIZATION ...what text to include and how to organize the book. We welcome your thoughts for improving future versions. The following materials were reprinted

ImmuneQuest: Assessment of a Video Game as a Supplement to an Undergraduate Immunology Course.

PubMed

Raimondi, Stacey L

2016-05-01

The study of immunology, particularly in this day and age, is an integral aspect of the training of future biologists, especially health professionals. Unfortunately, many students lose interest in or lack true comprehension of immunology due to the jargon of the field, preventing them from gaining a true conceptual understanding that is essential to all biological learning. To that end, a new video game, ImmuneQuest, has been developed that allows undergraduate students to "be" cells in the immune system, finding and attacking pathogens, while answering questions to earn additional abilities. The ultimate goal of ImmuneQuest is to allow students to understand how the major cells in the immune system work together to fight disease, rather than focusing on them as separate entities as is more commonly done in lecture material. This work provides the first assessment of ImmuneQuest in an upper-level immunology course. Students had significant gains in learning of information presented in ImmuneQuest compared with information discussed in lecture only. Furthermore, while students found the game "frustrating" at times, they agreed that the game aided their learning and recommended it for future courses. Taken together, these results suggest that ImmuneQuest appears to be a useful tool to supplement lecture material and increase student learning and comprehension.

Optimal vibration control of a rotating plate with self-sensing active constrained layer damping

NASA Astrophysics Data System (ADS)

Xie, Zhengchao; Wong, Pak Kin; Lo, Kin Heng

2012-04-01

This paper proposes a finite element model for optimally controlled constrained layer damped (CLD) rotating plate with self-sensing technique and frequency-dependent material property in both the time and frequency domain. Constrained layer damping with viscoelastic material can effectively reduce the vibration in rotating structures. However, most existing research models use complex modulus approach to model viscoelastic material, and an additional iterative approach which is only available in frequency domain has to be used to include the material's frequency dependency. It is meaningful to model the viscoelastic damping layer in rotating part by using the anelastic displacement fields (ADF) in order to include the frequency dependency in both the time and frequency domain. Also, unlike previous ones, this finite element model treats all three layers as having the both shear and extension strains, so all types of damping are taken into account. Thus, in this work, a single layer finite element is adopted to model a three-layer active constrained layer damped rotating plate in which the constraining layer is made of piezoelectric material to work as both the self-sensing sensor and actuator under an linear quadratic regulation (LQR) controller. After being compared with verified data, this newly proposed finite element model is validated and could be used for future research.

Family food practices: relationships, materiality and the everyday at the end of life.

PubMed

Ellis, Julie

2018-02-01

This article draws on data from a research project that combined participant observation with in-depth interviews to explore family relationships and experiences of everyday life during life-threatening illness. In it I suggest that death has often been theorised in ways that make its 'mundane' practices less discernible. As a means to foreground the everyday, and to demonstrate its importance to the study of dying, this article explores the (re)negotiation of food and eating in families facing the end of life. Three themes that emerged from the study's broader focus on family life are discussed: 'food talk' and making sense of illness; food, family and identity; and food 'fights'. Together the findings illustrate the material, social and symbolic ways in which food acts relationally in the context of dying, extending conceptual work on materiality in death studies in novel directions. The article also contributes new empirical insights to a limited sociological literature on food, families and terminal illness, building on work that theorises the entanglements of materiality, food, bodies and care. The article concludes by highlighting the analytical value of everyday materialities such as food practices for future research on dying as a relational experience. © 2018 The Author. Sociology of Health & Illness published by John Wiley & Sons Ltd on behalf of Foundation for SHIL.

Proton irradiation on materials

NASA Technical Reports Server (NTRS)

Chang, C. Ken

1993-01-01

A computer code is developed by utilizing a radiation transport code developed at NASA Langley Research Center to study the proton radiation effects on materials which have potential application in NASA's future space missions. The code covers the proton energy from 0.01 Mev to 100 Gev and is sufficient for energetic protons encountered in both low earth and geosynchronous orbits. With some modification, the code can be extended for particles heavier than proton as the radiation source. The code is capable of calculating the range, stopping power, exit energy, energy deposition coefficients, dose, and cumulative dose along the path of the proton in a target material. The target material can be any combination of the elements with atomic number ranging from 1 to 92, or any compound with known chemical composition. The generated cross section for a material is stored and is reused in future to save computer time. This information can be utilized to calculate the proton dose a material would receive in an orbit when the radiation environment is known. It can also be used to determine, in the laboratory, the parameters such as beam current of proton and irradiation time to attain the desired dosage for accelerated ground testing of any material. It is hoped that the present work be extended to include polymeric and composite materials which are prime candidates for use as coating, electronic components, and structure building. It is also desirable to determine, for ground testing these materials, the laboratory parameters in order to simulate the dose they would receive in space environments. A sample print-out for water subject to 1.5 Mev proton is included as a reference.

Superhydrophobic Materials for Biomedical Applications

PubMed Central

Colson, Yolonda L.; Grinstaff, Mark W.

2016-01-01

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 state 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 surfaces for biomedical applications. PMID:27449946

HEP Software Foundation Community White Paper Working Group - Detector Simulation

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

Apostolakis, J.

A working group on detector simulation was formed as part of the high-energy physics (HEP) Software Foundation's initiative to prepare a Community White Paper that describes the main software challenges and opportunities to be faced in the HEP field over the next decade. The working group met over a period of several months in order to review the current status of the Full and Fast simulation applications of HEP experiments and the improvements that will need to be made in order to meet the goals of future HEP experimental programmes. The scope of the topics covered includes the main componentsmore » of a HEP simulation application, such as MC truth handling, geometry modeling, particle propagation in materials and fields, physics modeling of the interactions of particles with matter, the treatment of pileup and other backgrounds, as well as signal processing and digitisation. The resulting work programme described in this document focuses on the need to improve both the software performance and the physics of detector simulation. The goals are to increase the accuracy of the physics models and expand their applicability to future physics programmes, while achieving large factors in computing performance gains consistent with projections on available computing resources.« less

Removal of Organic Pollutants from Water Using Superwetting Materials.

PubMed

Li, Lingxiao; Zhang, Junping; Wang, Aiqin

2018-02-01

The frequent occurrence of water pollution accidents and the leakage of organic pollutants have caused severe environmental and ecological crisis. It is thus highly imperative to find efficient materials to solve the problem. Inspired by the lotus leaf, superwetting materials are receiving increasing attention in the field of removal of organic pollutants from water. Various superwetting materials have been successfully generated and integrated into devices for removal of organic pollutants from water. On the basis of our previous work in the field, we summarized in this account the progress of removal of (1) floating and underwater insoluble, (2) emulsified insoluble, and (3) both insoluble and soluble organic pollutants from water using superwetting materials including superhydrophobic & superoleophilic materials, superhydrophilic & underwater superoleophobic materials, and materials with controllable wettability. The superwetting materials are in the forms of 2D porous materials, 3D porous materials and particles, etc. Finally, the current state and future challenges in this field are discussed. We hope this account could shed light on the design of novel superwetting materials for efficient removal of organic pollutants from water. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Education and training for implementation science: our interest in manuscripts describing education and training materials.

PubMed

Straus, Sharon E; Sales, Anne; Wensing, Michel; Michie, Susan; Kent, Bridie; Foy, Robbie

2015-09-28

Alongside the growth in interest in implementation science, there has been a marked increase in training programs, educational courses, degrees, and other offerings in implementation research and practice to meet the demand for this expertise. We believe that the science of capacity building has matured but that we can advance it further by shining light on excellent work in this area and by highlighting gaps for future research. At Implementation Science, we regularly receive manuscripts that describe or evaluate training materials, competencies, and competency development in implementation curricula. We are announcing a renewed interest in manuscripts in this area, with specifications described below.

Cyborgian Material Design for Solar Fuel Production: The Emerging Photosynthetic Biohybrid Systems.

PubMed

Sakimoto, Kelsey K; Kornienko, Nikolay; Yang, Peidong

2017-03-21

Photosynthetic biohybrid systems (PBSs) combine the strengths of inorganic materials and biological catalysts by exploiting semiconductor broadband light absorption to capture solar energy and subsequently transform it into valuable CO 2 -derived chemicals by taking advantage of the metabolic pathways in living organisms. In this work, we first traverse through a brief history of recent PBSs, demonstrating the modularity and diversity of possible architectures to rival and, in many cases, surpass the performance of chemistry or biology alone before envisioning the future of these hybrid systems, opportunities for improvement, and its role in sustainable living here on earth and beyond.

Materials science. Modeling strain hardening the hard way.

PubMed

Gumbsch, Peter

2003-09-26

The plastic deformation of metals results in strain hardening, that is, an increase in the stress with increasing strain. Materials engineers can provide a simple approximate description of such deformation and hardening behavior. In his perspective, Gumbsch discusses work by Madec et al. who have undertaken the formidable task of computing the physical basis for the development of strain hardening by individually following the fate of all the dislocations involved. Their simulations show that the collinear dislocation interaction makes a substantial contribution to strain hardening. It is likely that such simulations will play an important role in guiding the development of future engineering descriptions of deformation and hardening.

Computational predictions of zinc oxide hollow structures

NASA Astrophysics Data System (ADS)

Tuoc, Vu Ngoc; Huan, Tran Doan; Thao, Nguyen Thi

2018-03-01

Nanoporous materials are emerging as potential candidates for a wide range of technological applications in environment, electronic, and optoelectronics, to name just a few. Within this active research area, experimental works are predominant while theoretical/computational prediction and study of these materials face some intrinsic challenges, one of them is how to predict porous structures. We propose a computationally and technically feasible approach for predicting zinc oxide structures with hollows at the nano scale. The designed zinc oxide hollow structures are studied with computations using the density functional tight binding and conventional density functional theory methods, revealing a variety of promising mechanical and electronic properties, which can potentially find future realistic applications.

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

Humphrey, Betty; Bland, Jesse John

This paper documents the history of the TRU program at Sandia, previous and current activities associated with TRU material and waste, interfaces with other TRU waste generator sites and the Waste Isolation Pilot Plan (WIPP), and paths forward for TRU material and waste. This document is a snapshot in time of the TRU program and should be updated as necessary, or when significant changes have occurred in the Sandia TRU program or in the TRU regulatory environment. This paper should serve as a roadmap to capture past TRU work so that efforts are not repeated and ground is not lostmore » due to future inactivity and personnel changes.« less

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.

An Automated Ab Initio Framework for Identifying New Ferroelectrics

NASA Astrophysics Data System (ADS)

Smidt, Tess; Reyes-Lillo, Sebastian E.; Jain, Anubhav; Neaton, Jeffrey B.

Ferroelectric materials have a wide-range of technological applications including non-volatile RAM and optoelectronics. In this work, we present an automated first-principles search for ferroelectrics. We integrate density functional theory, crystal structure databases, symmetry tools, workflow software, and a custom analysis toolkit to build a library of known and proposed ferroelectrics. We screen thousands of candidates using symmetry relations between nonpolar and polar structure pairs. We use two search strategies 1) polar-nonpolar pairs with the same composition and 2) polar-nonpolar structure type pairs. Results are automatically parsed, stored in a database, and accessible via a web interface showing distortion animations and plots of polarization and total energy as a function of distortion. We benchmark our results against experimental data, present new ferroelectric candidates found through our search, and discuss future work on expanding this search methodology to other material classes such as anti-ferroelectrics and multiferroics.

KSC-2011-7393

NASA Image and Video Library

2011-10-14

CAPE CANAVERAL, Fla. – Mechanical engineering students from Louisiana State University joined engineers and scientists at Launch Pad 39B at NASA's Kennedy Space Center in Florida as the students toured the facility to have a look at the flame trench. Designers are looking for new, flame and vibration-resistant materials to line the trench. To help in the search, a team of mechanical engineering students at Louisiana State University are to build a scaled-down version of the flame trench that Kennedy's scientists can use to try out sample materials for the trench. If the samples work in the lab, they can be tried out in the real flame trenches at Launch Pad 39A and 39B. The launch pad has been refurbished extensively and work is continuing to modify the pad to support a variety of launch vehicles in the future. Photo credit: NASA/Jim Grossmann

KSC-2011-7394

NASA Image and Video Library

2011-10-14

CAPE CANAVERAL, Fla. – Mechanical engineering students from Louisiana State University joined engineers and scientists at Launch Pad 39B at NASA's Kennedy Space Center in Florida as the students toured the facility to have a look at the flame trench. Designers are looking for new, flame and vibration-resistant materials to line the trench. To help in the search, a team of mechanical engineering students at Louisiana State University are to build a scaled-down version of the flame trench that Kennedy's scientists can use to try out sample materials for the trench. If the samples work in the lab, they can be tried out in the real flame trenches at Launch Pad 39A and 39B. The launch pad has been refurbished extensively and work is continuing to modify the pad to support a variety of launch vehicles in the future. Photo credit: NASA/Jim Grossmann

KSC-2011-7397

NASA Image and Video Library

2011-10-14

CAPE CANAVERAL, Fla. – Louisiana State University mechanical engineering students Kevin Schenker, from left, and Jacob Koch join Luz Marina Calle, a scientist at NASA's Kennedy Space in Florida, as they examine a portion of the wall of the flame trench at Launch Pad 39B. Designers are looking for new, flame and vibration-resistant materials to line the trench. To help in the search, a team of mechanical engineering students at Louisiana State University are to build a scaled-down version of the flame trench that Kennedy's scientists can use to try out sample materials for the trench. If the samples work in the lab, they can be tried out in the real flame trenches at Launch Pad 39A and 39B. The launch pad has been refurbished extensively and work is continuing to modify the pad to support a variety of launch vehicles in the future. Photo credit: NASA/Jim Grossmann

KSC-2011-7395

NASA Image and Video Library

2011-10-14

CAPE CANAVERAL, Fla. – Mechanical engineering students from Louisiana State University, the group on the left, joined engineers and scientists at Launch Pad 39B at NASA's Kennedy Space Center in Florida as the students toured the facility to have a look at the flame trench. Designers are looking for new, flame and vibration-resistant materials to line the trench. To help in the search, a team of mechanical engineering students at Louisiana State University are to build a scaled-down version of the flame trench that Kennedy's scientists can use to try out sample materials for the trench. If the samples work in the lab, they can be tried out in the real flame trenches at Launch Pad 39A and 39B. The launch pad has been refurbished extensively and work is continuing to modify the pad to support a variety of launch vehicles in the future. Photo credit: NASA/Jim Grossmann

Paternal Multiple Partner Fertility and Environmental Chaos Among Unmarried Nonresident Fathers

PubMed Central

Petren, Raymond E.

2017-01-01

This study examined the association between paternal multiple partner fertility (MPF; having children with two or more partners) and indicators of environmental chaos (partnership instability, residential instability, work stability, material hardship, and perceived social support) among unmarried, non-resident fathers. Survey data from the Fragile Families and Child Wellbeing Study (N = 873) were used to compare unmarried non-resident fathers who experienced MPF to those who had children with one partner. Results show that paternal MPF is associated with most indicators of environmental chaos (greater partnership instability, residential instability, work instability, material hardship), but not social support. Results suggest that fathers who experience MPF face challenges beyond those of other non-resident fathers. Policies and interventions should address aspects of instability and hardship that are unique to paternal MPF in order to encourage fathers’ positive contributions to children and families. Directions for future research are discussed. PMID:29755155

Non-equilibrium assembly of microtubules: from molecules to autonomous chemical robots.

PubMed

Hess, H; Ross, Jennifer L

2017-09-18

Biological systems have evolved to harness non-equilibrium processes from the molecular to the macro scale. It is currently a grand challenge of chemistry, materials science, and engineering to understand and mimic biological systems that have the ability to autonomously sense stimuli, process these inputs, and respond by performing mechanical work. New chemical systems are responding to the challenge and form the basis for future responsive, adaptive, and active materials. In this article, we describe a particular biochemical-biomechanical network based on the microtubule cytoskeletal filament - itself a non-equilibrium chemical system. We trace the non-equilibrium aspects of the system from molecules to networks and describe how the cell uses this system to perform active work in essential processes. Finally, we discuss how microtubule-based engineered systems can serve as testbeds for autonomous chemical robots composed of biological and synthetic components.

Long Duration Sorbent Testbed

NASA Technical Reports Server (NTRS)

Howard, David F.; Knox, James C.; Long, David A.; Miller, Lee; Cmaric, Gregory; Thomas, John

2016-01-01

The Long Duration Sorbent Testbed (LDST) is a flight experiment demonstration designed to expose current and future candidate carbon dioxide removal system sorbents to an actual crewed space cabin environment to assess and compare sorption working capacity degradation resulting from long term operation. An analysis of sorbent materials returned to Earth after approximately one year of operation in the International Space Station's (ISS) Carbon Dioxide Removal Assembly (CDRA) indicated as much as a 70% loss of working capacity of the silica gel desiccant material at the extreme system inlet location, with a gradient of capacity loss down the bed. The primary science objective is to assess the degradation of potential sorbents for exploration class missions and ISS upgrades when operated in a true crewed space cabin environment. A secondary objective is to compare degradation of flight test to a ground test unit with contaminant dosing to determine applicability of ground testing.

Analytical, Experimental, and Modelling Studies of Lunar and Terrestrial Rocks

NASA Technical Reports Server (NTRS)

Haskin, Larry A.

1997-01-01

The goal of our research has been to understand the paths and the processes of planetary evolution that produced planetary surface materials as we find them. Most of our work has been on lunar materials and processes. We have done studies that obtain geological knowledge from detailed examination of regolith materials and we have reported implications for future sample-collecting and on-surface robotic sensing missions. Our approach has been to study a suite of materials that we have chosen in order to answer specific geologic questions. We continue this work under NAG5-4172. The foundation of our work has been the study of materials with precise chemical and petrographic analyses, emphasizing analysis for trace chemical elements. We have used quantitative models as tests to account for the chemical compositions and mineralogical properties of the materials in terms of regolith processes and igneous processes. We have done experiments as needed to provide values for geochemical parameters used in the models. Our models take explicitly into account the physical as well as the chemical processes that produced or modified the materials. Our approach to planetary geoscience owes much to our experience in terrestrial geoscience, where samples can be collected in field context and sampling sites revisited if necessary. Through studies of terrestrial analog materials, we have tested our ideas about the origins of lunar materials. We have been mainly concerned with the materials of the lunar highland regolith, their properties, their modes of origin, their provenance, and how to extrapolate from their characteristics to learn about the origin and evolution of the Moon's early igneous crust. From this work a modified model for the Moon's structure and evolution is emerging, one of globally asymmetric differentiation of the crust and mantle to produce a crust consisting mainly of ferroan and magnesian igneous rocks containing on average 70-80% plagioclase, with a large, mafic, trace-element-rich geochemical province, and a regolith that globally contains trace-element-rich material distributed from this province by the Imbrium basin-forming impact. This contrasts with earlier models of a concentrically zoned Moon with a crust of ferroan anorthosite overlying a layer of urKREEP overlying ultramafic cumulates. From this work, we have learned lessons useful for developing strategies for studying regolith materials that help to maximize the information available about both the evolution of the regolith and the igneous differentiation of the planet. We believe these lessons are useful in developing strategies for on-surface geological, mineralogical, and geochemical studies, as well. The main results of our work are given in the following brief summaries of major tasks. Detailed accounts of these results have been submitted in the annual progress reports.

Graduate Student Program in Materials and Engineering Research and Development for Future Accelerators

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

Spentzouris, Linda

The objective of the proposal was to develop graduate student training in materials and engineering research relevant to the development of particle accelerators. Many components used in today's accelerators or storage rings are at the limit of performance. The path forward in many cases requires the development of new materials or fabrication techniques, or a novel engineering approach. Often, accelerator-based laboratories find it difficult to get top-level engineers or materials experts with the motivation to work on these problems. The three years of funding provided by this grant was used to support development of accelerator components through a multidisciplinary approachmore » that cut across the disciplinary boundaries of accelerator physics, materials science, and surface chemistry. The following results were achieved: (1) significant scientific results on fabrication of novel photocathodes, (2) application of surface science and superconducting materials expertise to accelerator problems through faculty involvement, (3) development of instrumentation for fabrication and characterization of materials for accelerator components, (4) student involvement with problems at the interface of material science and accelerator physics.« less

Source Identification of Human Biological Materials and Its Prospect in Forensic Science.

PubMed

Zou, K N; Gui, C; Gao, Y; Yang, F; Zhou, H G

2016-06-01

Source identification of human biological materials in crime scene plays an important role in reconstructing the crime process. Searching specific genetic markers to identify the source of different human biological materials is the emphasis and difficulty of the research work of legal medical experts in recent years. This paper reviews the genetic markers which are used for identifying the source of human biological materials and studied widely, such as DNA methylation, mRNA, microRNA, microflora and protein, etc. By comparing the principles and methods of source identification of human biological materials using different kinds of genetic markers, different source of human biological material owns suitable marker types and can be identified by detecting single genetic marker or combined multiple genetic markers. Though there is no uniform standard and method for identifying the source of human biological materials in forensic laboratories at present, the research and development of a series of mature and reliable methods for distinguishing different human biological materials play the role as forensic evidence which will be the future development direction. Copyright© by the Editorial Department of Journal of Forensic Medicine.

The present and future of microplastic pollution in the marine environment.

PubMed

Ivar do Sul, Juliana A; Costa, Monica F

2014-02-01

Recently, research examining the occurrence of microplastics in the marine environment has substantially increased. Field and laboratory work regularly provide new evidence on the fate of microplastic debris. This debris has been observed within every marine habitat. In this study, at least 101 peer-reviewed papers investigating microplastic pollution were critically analysed (Supplementary material). Microplastics are commonly studied in relation to (1) plankton samples, (2) sandy and muddy sediments, (3) vertebrate and invertebrate ingestion, and (4) chemical pollutant interactions. All of the marine organism groups are at an eminent risk of interacting with microplastics according to the available literature. Dozens of works on other relevant issues (i.e., polymer decay at sea, new sampling and laboratory methods, emerging sources, externalities) were also analysed and discussed. This paper provides the first in-depth exploration of the effects of microplastics on the marine environment and biota. The number of scientific publications will increase in response to present and projected plastic uses and discard patterns. Therefore, new themes and important approaches for future work are proposed. Copyright © 2013 Elsevier Ltd. All rights reserved.

How to Get Successfully Involved with K-12 Education

NASA Astrophysics Data System (ADS)

Duncan, D.; Fraknoi, A.; Bennett, M.

1998-05-01

Many astronomers now have some involvement in K-12 education, either through their children, through large projects with an education or outreach office, or through an educational component to their own grants. Some may need to incorporate education components into future proposals. For those new to education, it can be difficult to decide how best to use their limited resources without "re-inventing the wheel." Some astronomers are comfortable taking a direct role in the classroom or working with teachers, others prefer developing web-based or printed materials, while still others wouldrather work with local schools of education to enhance the training of future teachers. Which of these roles is most useful? In this session, participants will learn what has worked well in the past, with special attention paid to ways in which astronomers' and physicists' training and instincts may fail them when working in education. Invited teachers will describe their classrooms and how astronomers can be most helpful to them. Sample (successful) activities will be demonstrated, and information given about the wide range of existing astronomy and space-science education programs around the country. A full menu of useful ways that astronomers can get involved will be presented, as well as the organizations and institutions which can help in devising a meaningful education program. Handouts will include a catalog of national astronomy education projects, a list of educational web sites, information about the NASA OSS education brokers and facilitators, examples of successful educational materials, and a listing of roles astronomers have played or could play to enhance K-12 education. Registration is required; see the AAS Education WWW page or email aased@aas.org.

Future Sources of Organic Raw Materials.

ERIC Educational Resources Information Center

Shapiro, Irving S.

1978-01-01

Examines the need for industrial organization, academic institutions, and national governments to agree on cooperative roles in planning the future raw materials demands of the chemical industry. Political and social concerns, as well as technical and economic considerations, are important to the raw material future of the industry. (MA)

Efficiency of Launching Highly Confined Polaritons by Infrared Light Incident on a Hyperbolic Material.

PubMed

Dai, Siyuan; Ma, Qiong; Yang, Yafang; Rosenfeld, Jeremy; Goldflam, Michael D; McLeod, Alex; Sun, Zhiyuan; Andersen, Trond I; Fei, Zhe; Liu, Mengkun; Shao, Yinming; Watanabe, Kenji; Taniguchi, Takashi; Thiemens, Mark; Keilmann, Fritz; Jarillo-Herrero, Pablo; Fogler, Michael M; Basov, D N

2017-09-13

We investigated phonon-polaritons in hexagonal boron nitride-a naturally hyperbolic van der Waals material-by means of the scattering-type scanning near-field optical microscopy. Real-space nanoimages we have obtained detail how the polaritons are launched when the light incident on a thin hexagonal boron nitride slab is scattered by various intrinsic and extrinsic inhomogeneities, including sample edges, metallic nanodisks deposited on its top surface, random defects, and surface impurities. The scanned tip of the near-field microscope is itself a polariton launcher whose efficiency proves to be superior to all the other types of polariton launchers we studied. Our work may inform future development of polaritonic nanodevices as well as fundamental studies of collective modes in van der Waals materials.

Impact resistance of materials for guards on cutting machine tools--requirements in future European safety standards.

PubMed

Mewes, D; Trapp, R P

2000-01-01

Guards on machine tools are meant to protect operators from injuries caused by tools, workpieces, and fragments hurled out of the machine's working zone. This article presents the impact resistance requirements, which guards according to European safety standards for machine tools must satisfy. Based upon these standards the impact resistance of different guard materials was determined using cylindrical steel projectiles. Polycarbonate proves to be a suitable material for vision panels because of its high energy absorption capacity. The impact resistance of 8-mm thick polycarbonate is roughly equal to that of a 3-mm thick steel sheet Fe P01. The limited ageing stability, however, makes it necessary to protect polycarbonate against cooling lubricants by means of additional panes on both sides.

An overview of molecular acceptors for organic solar cells

NASA Astrophysics Data System (ADS)

Hudhomme, Piétrick

2013-07-01

Organic solar cells (OSCs) have gained serious attention during the last decade and are now considered as one of the future photovoltaic technologies for low-cost power production. The first dream of attaining 10% of power coefficient efficiency has now become a reality thanks to the development of new materials and an impressive work achieved to understand, control and optimize structure and morphology of the device. But most of the effort devoted to the development of new materials concerned the optimization of the donor material, with less attention for acceptors which to date remain dominated by fullerenes and their derivatives. This short review presents the progress in the use of non-fullerene small molecules and fullerene-based acceptors with the aim of evaluating the challenge for the next generation of acceptors in organic photovoltaics.

The Role of Computer Simulation in Nanoporous Metals—A Review

PubMed Central

Xia, Re; Wu, Run Ni; Liu, Yi Lun; Sun, Xiao Yu

2015-01-01

Nanoporous metals (NPMs) have proven to be all-round candidates in versatile and diverse applications. In this decade, interest has grown in the fabrication, characterization and applications of these intriguing materials. Most existing reviews focus on the experimental and theoretical works rather than the numerical simulation. Actually, with numerous experiments and theory analysis, studies based on computer simulation, which may model complex microstructure in more realistic ways, play a key role in understanding and predicting the behaviors of NPMs. In this review, we present a comprehensive overview of the computer simulations of NPMs, which are prepared through chemical dealloying. Firstly, we summarize the various simulation approaches to preparation, processing, and the basic physical and chemical properties of NPMs. In this part, the emphasis is attached to works involving dealloying, coarsening and mechanical properties. Then, we conclude with the latest progress as well as the future challenges in simulation studies. We believe that highlighting the importance of simulations will help to better understand the properties of novel materials and help with new scientific research on these materials. PMID:28793491

On the prevailing construction waste recycling practices: a South East Queensland study.

PubMed

Tam, Vivian W Y; Kotrayothar, Duangthidar; Loo, Yew-Chaye

2009-03-01

Waste generated from construction and building demolition work constitutes about 68% of all solid waste generated each year in South East Queensland. Consequently, it has created a serious waste management problem. The State Governments of Victoria and New South Wales have been encouraging the use of recycled materials from construction and related waste; they have also promulgated specifications for their use. In Queensland, however, similar regulations are not anticipated in the near future, which explains the lack of funded research conducted in this important arena. This paper presents an evaluation of the prevailing waste recycling practices in Queensland. Nine sites were visited, including two construction sites, three demolition sites, three recycling plants and one landfill in South East Queensland. The difficulties encountered by the recycling programme operators and their associates at these sites are described and the benefits of recycling construction materials are presented. One of the major barriers is that the local councils disallow the use of recycled materials in new construction work. To help rectify these impediments to recycling, recommendations are given to increase the use of recycled construction waste in South East Queensland.

A review of carbon-based and non-carbon-based catalyst supports for the selective catalytic reduction of nitric oxide

PubMed Central

Anthonysamy, Shahreen Binti Izwan; Afandi, Syahidah Binti; Khavarian, Mehrnoush

2018-01-01

Various types of carbon-based and non-carbon-based catalyst supports for nitric oxide (NO) removal through selective catalytic reduction (SCR) with ammonia are examined in this review. A number of carbon-based materials, such as carbon nanotubes (CNTs), activated carbon (AC), and graphene (GR) and non-carbon-based materials, such as Zeolite Socony Mobil–5 (ZSM-5), TiO2, and Al2O3 supported materials, were identified as the most up-to-date and recently used catalysts for the removal of NO gas. The main focus of this review is the study of catalyst preparation methods, as this is highly correlated to the behaviour of NO removal. The general mechanisms involved in the system, the Langmuir–Hinshelwood or Eley–Riedeal mechanism, are also discussed. Characterisation analysis affecting the surface and chemical structure of the catalyst is also detailed in this work. Finally, a few major conclusions are drawn and future directions for work on the advancement of the SCR-NH3 catalyst are suggested. PMID:29600136

A review of carbon-based and non-carbon-based catalyst supports for the selective catalytic reduction of nitric oxide.

PubMed

Anthonysamy, Shahreen Binti Izwan; Afandi, Syahidah Binti; Khavarian, Mehrnoush; Mohamed, Abdul Rahman Bin

2018-01-01

Various types of carbon-based and non-carbon-based catalyst supports for nitric oxide (NO) removal through selective catalytic reduction (SCR) with ammonia are examined in this review. A number of carbon-based materials, such as carbon nanotubes (CNTs), activated carbon (AC), and graphene (GR) and non-carbon-based materials, such as Zeolite Socony Mobil-5 (ZSM-5), TiO 2 , and Al 2 O 3 supported materials, were identified as the most up-to-date and recently used catalysts for the removal of NO gas. The main focus of this review is the study of catalyst preparation methods, as this is highly correlated to the behaviour of NO removal. The general mechanisms involved in the system, the Langmuir-Hinshelwood or Eley-Riedeal mechanism, are also discussed. Characterisation analysis affecting the surface and chemical structure of the catalyst is also detailed in this work. Finally, a few major conclusions are drawn and future directions for work on the advancement of the SCR-NH 3 catalyst are suggested.

Amidation reaction of eugenyl oxyacetate ethyl ester with 1,3 diaminopropane

NASA Astrophysics Data System (ADS)

Suryanti, V.; Wibowo, F. R.; Kusumaningsih, T.; Wibowo, A. H.; Khumaidah, S. A.; Wijayanti, L. A.

2016-04-01

Eugenol having various substituents on the aromatic ring (hydroxy, methoxy and allyl) are useful for starting material in synthesizing of its derivatives. Eugenol derivatives have shown wide future potential applications in many areas, especially as future drugs against many diseases. The aim of this work was to synthesize an amide of eugenol derivative. The starting material used was eugenol from clove oil and the reaction was conducted in 3 step reactions to give the final product. Firstly, eugenol was converted into eugenyl oxyacetate [2-(4-allyl-2-methoxyphenoxy) acetic acid] as a white crystal with 70.5% yield, which was then esterified with ethanol to have eugenyl oxyacetate ethyl ester [ethyl 2-(4-allyl-2-methoxyphenoxy) acetate] as brown liquid in 75.7%. The last step was the reaction between eugenyl oxyacetate ethyl ester and 1,3 diaminopropane to give 2-(4-allyl-2-methoxyphenoxy)-N-(3-aminopropyl) acetamide as a brown powder with 71.6% yield, where the amidation reaction was occurred.

High-temperature electronics

NASA Technical Reports Server (NTRS)

Seng, Gary T.

1987-01-01

In recent years, there was a growing need for electronics capable of sustained high-temperature operation for aerospace propulsion system instrumentation, control and condition monitoring, and integrated sensors. The desired operating temperature in some applications exceeds 600 C, which is well beyond the capability of currently available semiconductor devices. Silicon carbide displays a number of properties which make it very attractive as a semiconductor material, one of which is the ability to retain its electronic integrity at temperatures well above 600 C. An IR-100 award was presented to NASA Lewis in 1983 for developing a chemical vapor deposition process to grow single crystals of this material on standard silicon wafers. Silicon carbide devices were demonstrated above 400 C, but much work remains in the areas of crystal growth, characterization, and device fabrication before the full potential of silicon carbide can be realized. The presentation will conclude with current and future high-temperature electronics program plans. Although the development of silicon carbide falls into the category of high-risk research, the future looks promising, and the potential payoffs are tremendous.

Nanostructured Black Phosphorus/Ketjenblack-Multiwalled Carbon Nanotubes Composite as High Performance Anode Material for Sodium-Ion Batteries.

PubMed

Xu, Gui-Liang; Chen, Zonghai; Zhong, Gui-Ming; Liu, Yuzi; Yang, Yong; Ma, Tianyuan; Ren, Yang; Zuo, Xiaobing; Wu, Xue-Hang; Zhang, Xiaoyi; Amine, Khalil

2016-06-08

Sodium-ion batteries are promising alternatives to lithium-ion batteries for large-scale applications. However, the low capacity and poor rate capability of existing anodes for sodium-ion batteries are bottlenecks for future developments. Here, we report a high performance nanostructured anode material for sodium-ion batteries that is fabricated by high energy ball milling to form black phosphorus/Ketjenblack-multiwalled carbon nanotubes (BPC) composite. With this strategy, the BPC composite with a high phosphorus content (70 wt %) could deliver a very high initial Coulombic efficiency (>90%) and high specific capacity with excellent cyclability at high rate of charge/discharge (∼1700 mAh g(-1) after 100 cycles at 1.3 A g(-1) based on the mass of P). In situ electrochemical impedance spectroscopy, synchrotron high energy X-ray diffraction, ex situ small/wide-angle X-ray scattering, high resolution transmission electronic microscopy, and nuclear magnetic resonance were further used to unravel its superior sodium storage performance. The scientific findings gained in this work are expected to serve as a guide for future design on high performance anode material for sodium-ion batteries.

Active counter electrode in a-SiC electrochemical metallization memory

NASA Astrophysics Data System (ADS)

Morgan, K. A.; Fan, J.; Huang, R.; Zhong, L.; Gowers, R.; Ou, J. Y.; Jiang, L.; De Groot, C. H.

2017-08-01

Cu/amorphous-SiC (a-SiC) electrochemical metallization memory cells have been fabricated with two different counter electrode (CE) materials, W and Au, in order to investigate the role of CEs in a non-oxide semiconductor switching matrix. In a positive bipolar regime with Cu filaments forming and rupturing, the CE influences the OFF state resistance and minimum current compliance. Nevertheless, a similarity in SET kinetics is seen for both CEs, which differs from previously published SiO2 memories, confirming that CE effects are dependent on the switching layer material or type. Both a-SiC memories are able to switch in the negative bipolar regime, indicating Au and W filaments. This confirms that CEs can play an active role in a non-oxide semiconducting switching matrix, such as a-SiC. By comparing both Au and W CEs, this work shows that W is superior in terms of a higher R OFF/R ON ratio, along with the ability to switch at lower current compliances making it a favourable material for future low energy applications. With its CMOS compatibility, a-SiC/W is an excellent choice for future resistive memory applications.

Design of lateral heterostructure from arsenene and antimonene

NASA Astrophysics Data System (ADS)

Sun, Qilong; Dai, Ying; Ma, Yandong; Yin, Na; Wei, Wei; Yu, Lin; Huang, Baibiao

2016-09-01

Lateral heterostructures fabricated by two-dimensional building blocks have opened up exciting realms in material science and device physics. Identifying suitable materials for creating such heterostructures is urgently needed for the next-generation devices. Here, we demonstrate a novel type of seamless lateral heterostructures with excellent stabilities formed within pristine arsenene and antimonene. We find that these heterostructures could possess direct and reduced energy gaps without any modulations. Moreover, the highly coveted type-II alignment and the high carrier mobility are also identified, marking the enhanced quantum efficiency. The tensile strain can result in efficient bandgap engineering. Besides, the proposed critical condition for favored direct energy gaps would have a guiding significance on the subsequent works. Generally, our predictions not only introduce new vitality into lateral heterostructures, enriching available candidate materials in this field, but also highlight the potential of these lateral heterostructures as appealing materials for future devices.

Identification of Upper and Lower Level Yield Strength in Materials

PubMed Central

Valíček, Jan; Harničárová, Marta; Kopal, Ivan; Palková, Zuzana; Kušnerová, Milena; Panda, Anton; Šepelák, Vladimír

2017-01-01

This work evaluates the possibility of identifying mechanical parameters, especially upper and lower yield points, by the analytical processing of specific elements of the topography of surfaces generated with abrasive waterjet technology. We developed a new system of equations, which are connected with each other in such a way that the result of a calculation is a comprehensive mathematical–physical model, which describes numerically as well as graphically the deformation process of material cutting using an abrasive waterjet. The results of our model have been successfully checked against those obtained by means of a tensile test. The main prospect for future applications of the method presented in this article concerns the identification of mechanical parameters associated with the prediction of material behavior. The findings of this study can contribute to a more detailed understanding of the relationships: material properties—tool properties—deformation properties. PMID:28832526

Identification of Upper and Lower Level Yield Strength in Materials.

PubMed

Valíček, Jan; Harničárová, Marta; Kopal, Ivan; Palková, Zuzana; Kušnerová, Milena; Panda, Anton; Šepelák, Vladimír

2017-08-23

This work evaluates the possibility of identifying mechanical parameters, especially upper and lower yield points, by the analytical processing of specific elements of the topography of surfaces generated with abrasive waterjet technology. We developed a new system of equations, which are connected with each other in such a way that the result of a calculation is a comprehensive mathematical-physical model, which describes numerically as well as graphically the deformation process of material cutting using an abrasive waterjet. The results of our model have been successfully checked against those obtained by means of a tensile test. The main prospect for future applications of the method presented in this article concerns the identification of mechanical parameters associated with the prediction of material behavior. The findings of this study can contribute to a more detailed understanding of the relationships: material properties-tool properties-deformation properties.

Band Structures and Transport Properties of High-Performance Half-Heusler Thermoelectric Materials by First Principles.

PubMed

Fang, Teng; Zhao, Xinbing; Zhu, Tiejun

2018-05-19

Half-Heusler (HH) compounds, with a valence electron count of 8 or 18, have gained popularity as promising high-temperature thermoelectric (TE) materials due to their excellent electrical properties, robust mechanical capabilities, and good high-temperature thermal stability. With the help of first-principles calculations, great progress has been made in half-Heusler thermoelectric materials. In this review, we summarize some representative theoretical work on band structures and transport properties of HH compounds. We introduce how basic band-structure calculations are used to investigate the atomic disorder in n-type M NiSb ( M = Ti, Zr, Hf) compounds and guide the band engineering to enhance TE performance in p-type Fe R Sb ( R = V, Nb) based systems. The calculations on electrical transport properties, especially the scattering time, and lattice thermal conductivities are also demonstrated. The outlook for future research directions of first-principles calculations on HH TE materials is also discussed.

Management of the aging of critical safety-related concrete structures in light-water reactor plants

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

Naus, D.J.; Oland, C.B.; Arndt, E.G.

1990-01-01

The Structural Aging Program has the overall objective of providing the USNRC with an improved basis for evaluating nuclear power plant safety-related structures for continued service. The program consists of a management task and three technical tasks: materials property data base, structural component assessment/repair technology, and quantitative methodology for continued-service determinations. Objectives, accomplishments, and planned activities under each of these tasks are presented. Major program accomplishments include development of a materials property data base for structural materials as well as an aging assessment methodology for concrete structures in nuclear power plants. Furthermore, a review and assessment of inservice inspection techniquesmore » for concrete materials and structures has been complete, and work on development of a methodology which can be used for performing current as well as reliability-based future condition assessment of concrete structures is well under way. 43 refs., 3 tabs.« less

A deterministic guide for material and mode dependence of on-chip electro-optic modulator performance

NASA Astrophysics Data System (ADS)

Amin, Rubab; Suer, Can; Ma, Zhizhen; Sarpkaya, Ibrahim; Khurgin, Jacob B.; Agarwal, Ritesh; Sorger, Volker J.

2017-10-01

Electro-optic modulation is a key function in optical data communication and possible future optical computing engines. The performance of modulators intricately depends on the interaction between the actively modulated material and the propagating waveguide mode. While high-performing modulators were demonstrated before, the approaches were taken as ad-hoc. Here we show the first systematic investigation to incorporate a holistic analysis for high-performance and ultra-compact electro-optic modulators on-chip. We show that intricate interplay between active modulation material and optical mode plays a key role in the device operation. Based on physical tradeoffs such as index modulation, loss, optical confinement factors and slow-light effects, we find that bias-material-mode regions exist where high phase modulation and high loss (absorption) modulation is found. This work paves the way for a holistic design rule of electro-optic modulators for on-chip integration.

Colloid and materials science for the conservation of cultural heritage: cleaning, consolidation, and deacidification.

PubMed

Baglioni, Piero; Chelazzi, David; Giorgi, Rodorico; Poggi, Giovanna

2013-04-30

Serendipity and experiment have been a frequent approach for the development of materials and methodologies used for a long time for either cleaning or consolidation of works of art. Recently, new perspectives have been opened by the application of materials science, colloid science, and interface science frameworks to conservation, generating a breakthrough in the development of innovative tools for the conservation and preservation of cultural heritage. This Article is an overview of the most recent contributions of colloid and materials science to the art conservation field, mainly focusing on the use of amphiphile-based fluids, gels, and alkaline earth metal hydroxide nanoparticles dispersions for the cleaning of pictorial surfaces, the consolidation of artistic substrates, and the deacidification of paper, canvas, and wood. Future possible directions for solving several conservation issues that still need to be faced are also highlighted.

Band Structures and Transport Properties of High-Performance Half-Heusler Thermoelectric Materials by First Principles

PubMed Central

Fang, Teng; Zhao, Xinbing

2018-01-01

Half-Heusler (HH) compounds, with a valence electron count of 8 or 18, have gained popularity as promising high-temperature thermoelectric (TE) materials due to their excellent electrical properties, robust mechanical capabilities, and good high-temperature thermal stability. With the help of first-principles calculations, great progress has been made in half-Heusler thermoelectric materials. In this review, we summarize some representative theoretical work on band structures and transport properties of HH compounds. We introduce how basic band-structure calculations are used to investigate the atomic disorder in n-type MNiSb (M = Ti, Zr, Hf) compounds and guide the band engineering to enhance TE performance in p-type FeRSb (R = V, Nb) based systems. The calculations on electrical transport properties, especially the scattering time, and lattice thermal conductivities are also demonstrated. The outlook for future research directions of first-principles calculations on HH TE materials is also discussed. PMID:29783759

Tough and tunable adhesion of hydrogels: experiments and models

NASA Astrophysics Data System (ADS)

Zhang, Teng; Yuk, Hyunwoo; Lin, Shaoting; Parada, German A.; Zhao, Xuanhe

2017-06-01

As polymer networks infiltrated with water, hydrogels are major constituents of animal and plant bodies and have diverse engineering applications. While natural hydrogels can robustly adhere to other biological materials, such as bonding of tendons and cartilage on bones and adhesive plaques of mussels, it is challenging to achieve such tough adhesions between synthetic hydrogels and engineering materials. Recent experiments show that chemically anchoring long-chain polymer networks of tough synthetic hydrogels on solid surfaces create adhesions tougher than their natural counterparts, but the underlying mechanism has not been well understood. It is also challenging to tune systematically the adhesion of hydrogels on solids. Here, we provide a quantitative understanding of the mechanism for tough adhesions of hydrogels on solid materials via a combination of experiments, theory, and numerical simulations. Using a coupled cohesive-zone and Mullins-effect model validated by experiments, we reveal the interplays of intrinsic work of adhesion, interfacial strength, and energy dissipation in bulk hydrogels in order to achieve tough adhesions. We further show that hydrogel adhesion can be systematically tuned by tailoring the hydrogel geometry and silanization time of solid substrates, corresponding to the control of energy dissipation zone and intrinsic work of adhesion, respectively. The current work further provides a theoretical foundation for rational design of future biocompatible and underwater adhesives.

THz Properties of Adhesives

NASA Astrophysics Data System (ADS)

Stübling, E.; Gomell, L.; Sommer, S.; Winkel, A.; Kahlmeyer, M.; Böhm, S.; Koch, M.

2018-04-01

We determined the THz properties of 12 different adhesives which are mainly used for industrial purposes. The adhesives applied can be classified according to their chemical structure: epoxy resins, acrylic resins, and polyurethane based materials. This work represents a basis for future studies, which will concentrate on aging effects, including the absorption of water of adhesive joints. Thus, the dielectric properties of the unaged adhesives are investigated and the results of these measurements are described herein.

Introducing Argonne’s Theta Supercomputer

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

None

Theta, the Argonne Leadership Computing Facility’s (ALCF) new Intel-Cray supercomputer, is officially open to the research community. Theta’s massively parallel, many-core architecture puts the ALCF on the path to Aurora, the facility’s future Intel-Cray system. Capable of nearly 10 quadrillion calculations per second, Theta enables researchers to break new ground in scientific investigations that range from modeling the inner workings of the brain to developing new materials for renewable energy applications.

THz Properties of Adhesives

NASA Astrophysics Data System (ADS)

Stübling, E.; Gomell, L.; Sommer, S.; Winkel, A.; Kahlmeyer, M.; Böhm, S.; Koch, M.

2018-06-01

We determined the THz properties of 12 different adhesives which are mainly used for industrial purposes. The adhesives applied can be classified according to their chemical structure: epoxy resins, acrylic resins, and polyurethane based materials. This work represents a basis for future studies, which will concentrate on aging effects, including the absorption of water of adhesive joints. Thus, the dielectric properties of the unaged adhesives are investigated and the results of these measurements are described herein.

A Critical Plane-energy Model for Multiaxial Fatigue Life Prediction of Homogeneous and Heterogeneous Materials

NASA Astrophysics Data System (ADS)

Wei, Haoyang

A new critical plane-energy model is proposed in this thesis for multiaxial fatigue life prediction of homogeneous and heterogeneous materials. Brief review of existing methods, especially on the critical plane-based and energy-based methods, are given first. Special focus is on one critical plane approach which has been shown to work for both brittle and ductile metals. The key idea is to automatically change the critical plane orientation with respect to different materials and stress states. One potential drawback of the developed model is that it needs an empirical calibration parameter for non-proportional multiaxial loadings since only the strain terms are used and the out-of-phase hardening cannot be considered. The energy-based model using the critical plane concept is proposed with help of the Mroz-Garud hardening rule to explicitly include the effect of non-proportional hardening under fatigue cyclic loadings. Thus, the empirical calibration for non-proportional loading is not needed since the out-of-phase hardening is naturally included in the stress calculation. The model predictions are compared with experimental data from open literature and it is shown the proposed model can work for both proportional and non-proportional loadings without the empirical calibration. Next, the model is extended for the fatigue analysis of heterogeneous materials integrating with finite element method. Fatigue crack initiation of representative volume of heterogeneous materials is analyzed using the developed critical plane-energy model and special focus is on the microstructure effect on the multiaxial fatigue life predictions. Several conclusions and future work is drawn based on the proposed study.

FY2014 Propulsion Materials R&D Annual Progress Report

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

None

The Propulsion Materials Program actively supports the energy security and reduction of greenhouse emissions goals of VTO by investigating and identifying the materials properties that are most essential for continued development of cost-effective, highly efficient, and environmentally friendly next-generation heavy and light-duty powertrains. The technical approaches available to enhance propulsion systems focus on improvements in both vehicle efficiency and fuel substitution, both of which must overcome the performance limitations of the materials currently in use. Propulsion Materials Program activities work with national laboratories, industry experts, and VTO powertrain systems (e.g., Advanced Combustion Engines [ACE], Advanced Power Electronics and Electrical Machinesmore » [APEEM], and fuels) teams to develop strategies that overcome materials limitations in future powertrain performance. The technical maturity of the portfolio of funded projects ranges from basic science to subsystem prototype validation. Projects within a Propulsion Materials Program activity address materials concerns that directly impact critical technology barriers within each of the above programs, including barriers that impact fuel efficiency, thermal management, emissions reduction, improved reliability, and reduced manufacturing costs. The program engages only the barriers that result from material property limitations and represent fundamental, high-risk materials issues.« less

FY2015 Propulsion Materials Annual Report

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

None, None

The Propulsion Materials Program actively supports the energy security and reduction of greenhouse emissions goals of VTO by investigating and identifying the materials properties that are most essential for continued development of cost-effective, highly efficient, and environmentally friendly next-generation heavy and light-duty powertrains. The technical approaches available to enhance propulsion systems focus on improvements in both vehicle efficiency and fuel substitution, both of which must overcome the performance limitations of the materials currently in use. Propulsion Materials Program activities work with national laboratories, industry experts, and VTO powertrain systems (e.g., Advanced Combustion Engines [ACE], Advanced Power Electronics and Electrical Machinesmore » [APEEM], and fuels) teams to develop strategies that overcome materials limitations in future powertrain performance. The technical maturity of the portfolio of funded projects ranges from basic science to subsystem prototype validation. Projects within a Propulsion Materials Program activity address materials concerns that directly impact critical technology barriers within each of the above programs, including barriers that impact fuel efficiency, thermal management, emissions reduction, improved reliability, and reduced manufacturing costs. The program engages only the barriers that result from material property limitations and represent fundamental, high-risk materials issues.« less

Laser beam joining of material combinations for automotive applications

NASA Astrophysics Data System (ADS)

Schubert, Emil; Zerner, Ingo; Sepold, Gerd

1997-08-01

An ideal material for automotive applications would combine the following properties: high corrosion resistance, high strength, high stiffness and not at least a low material price. Today a single material is not able to meet all these requirements. Therefore, in the future different materials will be placed where they meet the requirements best. The result of this consideration is a car body with many different alloys and metals, which have to be joined to one another. BIAS is working on the development of laser based joining technologies for different material combinations, especially for thin sheets used in automotive applications. One result of the research is a joining technology for an aluminum-steel-joint. Using a Nd:YAG laser the problem of brittle intermetallic phases between these materials was overcome. Using suitable temperature-time cycles, elected by a FEM-simulation, the thickness of intermetallic phases was kept below 10 micrometers . This technology was also applied to coated steels, which were joined with different aluminum alloys. Further it is demonstrated that titanium alloys, e.g. used for racing cars, can also be joined with aluminum alloys.

Proof of concept demonstration of novel technologies for lunar spacesuit dust mitigation

NASA Astrophysics Data System (ADS)

Manyapu, Kavya K.; De Leon, Pablo; Peltz, Leora; Gaier, James R.; Waters, Deborah

2017-08-01

A recent report by NASA identified dust/particulate mitigation techniques as a highly relevant study for future long-term planetary exploration missions (NASA, 2015). The deleterious effects of lunar dust on spacesuits discovered during the Apollo missions has compelled NASA to identify dust mitigation as a critical path for potential future lunar, asteroid and Mars missions. The complexity of spacesuit design has however constrained integrating existing dust cleaning technologies, formerly demonstrated on rigid surfaces, into the spacesuit system. Accordingly, this research is investigating novel methods to integrate dust mitigation technologies for use on spacesuits. We examine utilizing a novel combination of active and passive technologies integrated into the spacesuit outerlayer to alleviate dust contamination. Leveraging two specific technologies, the Electrodynamics Dust Shield (EDS) active technology and Work Function Matching Coating (WFM) passive technology, developed by NASA for rigid surfaces, we apply new high performance materials such as the Carbon Nanotube (CNT) flexible fibers to develop a spacesuit-integrated dust cleaning system. Through experiments conducted using JSC-1A lunar dust simulant on coupons made of spacesuit outerlayer material, feasibility of integrating the proposed dust cleaning system and its performance were assessed. Results from these preliminary experiments show that the integrated dust cleaning system is capable of removing 80-95% of dust from the spacesuit material demonstrating proof of concept. This paper describes the techniques and results from the experiments. Future challenges of implementing the proposed approach into fight suits are identified.

National Labs Host Classroom Ready Energy Educational Materials

NASA Astrophysics Data System (ADS)

Howell, C. D.

2009-12-01

The Department of Energy (DOE) has a clear goal of joining all climate and energy agencies in the task of taking climate and energy research and development to communities across the nation and throughout the world. Only as information on climate and energy education is shared with the nation and world do research labs begin to understand the massive outreach work yet to be accomplished. The work at hand is to encourage and ensure the climate and energy literacy of our society. The national labs have defined the K-20 population as a major outreach focus, with the intent of helping them see their future through the global energy usage crisis and ensure them that they have choices and a chance to redirect their future. Students embrace climate and energy knowledge and do see an opportunity to change our energy future in a positive way. Students are so engaged that energy clubs are springing up in highschools across the nation. Because of such global clubs university campuses are being connected throughout the world (Energy Crossroads www.energycrossroads.org) etc. There is a need and an interest, but what do teachers need in order to faciliate this learning? It is simple, they need financial support for classroom resources; standards based classroom ready lessons and materials; and, training. The National Renewable Energy Laboratory (NREL), a Department of Energy Lab, provides standards based education materials to schools across the nation. With a focus on renewable energy and energy efficiency education, NREL helps educators to prompt students to analyze and then question their energy choices and evaluate their carbon footprint. Classrooms can then discover the effects of those choices on greenhouse gas emmissions and climate change. The DOE Office of Science has found a way to contribute to teachers professional development through the Department of Energy Academics Creating Teacher Scientists (DOE ACTS) Program. This program affords teachers an opportunity to take research to the classroom. The DOE ACTS program is designed for science and math teachers seeking an independent research experience with a mentor scientist at a DOE National Laboratory to serve as technical leaders and agents of positive change in their local, regional and national communities. (www.scied.science.doe.gov/scied/ACTS/about.htm) The National Labs developed education materials and outreach combined with DOE ACTS are several small steps in the right direction. That is, a small step toward impacting and influencing thousands of youth across the nation (our future workforce) as only teachers can do. (www.rne2ew.org http://www1.eere.energy.gov/education/)

Preliminary analysis of accelerated space flight ionizing radiation testing

NASA Technical Reports Server (NTRS)

Wilson, J. W.; Stock, L. V.; Carter, D. J.; Chang, C. K.

1982-01-01

A preliminary analysis shows that radiation dose equivalent to 30 years in the geosynchronous environment can be accumulated in a typical composite material exposed to space for 2 years or less onboard a spacecraft orbiting from perigee of 300 km out to the peak of the inner electron belt (approximately 2750 km). Future work to determine spacecraft orbits better tailored to materials accelerated testing is indicated. It is predicted that a range of 10 to the 9th power to 10 to the 10th power rads would be accumulated in 3-6 mil thick epoxy/graphite exposed by a test spacecraft orbiting in the inner electron belt. This dose is equivalent to the accumulated dose that this material would be expected to have after 30 years in a geosynchronous orbit. It is anticipated that material specimens would be brought back to Earth after 2 years in the radiation environment so that space radiation effects on materials could be analyzed by laboratory methods.

Recommendations from the workshop on Comparative Approaches to Safety Assessment of GM Plant Materials: A road toward harmonized criteria?

PubMed

Bartholomaeus, Andrew; Batista, Juan Carlos; Burachik, Moisés; Parrott, Wayne

2015-01-01

An international meeting of genetically modified (GM) food safety assessors from the main importing and exporting countries from Asia and the Americas was held in Buenos Aires, Argentina, between June 26(th) and 28(th), 2013. Participants shared their evaluation approaches, identified similarities and challenges, and used their experience to propose areas for future work. Recommendations for improving risk assessment procedures and avenues for future collaboration were also discussed. The deliberations of the meeting were also supported by a survey of participants which canvassed risk assessment approaches across the regions from which participants came. This project was initiated by Argentine Agri-Food Health and Quality National Service (SENASA, Ministry of Agriculture, Argentina), with the support of the International Life Sciences Institute (ILSI) and other partner institutions. The importance of making all possible efforts toward more integrated and harmonized regulatory oversight for GM organisms (GMOs) was strongly emphasized. This exercise showed that such harmonization is a feasible goal that would contribute to sustain a fluid trade of commodities and ultimately enhance food security. Before this can be achieved, key issues identified in this meeting will have to be addressed in the near future to enable regulatory collaboration or joint work. The authors propose that the recommendations coming out of the meeting should be used as a basis for continuing work, follow up discussions and concrete actions.

Recommendations from the workshop on Comparative Approaches to Safety Assessment of GM Plant Materials: A road toward harmonized criteria?

PubMed Central

Bartholomaeus, Andrew; Batista, Juan Carlos; Burachik, Moisés; Parrott, Wayne

2015-01-01

ABSTRACT An international meeting of genetically modified (GM) food safety assessors from the main importing and exporting countries from Asia and the Americas was held in Buenos Aires, Argentina, between June 26th and 28th, 2013. Participants shared their evaluation approaches, identified similarities and challenges, and used their experience to propose areas for future work. Recommendations for improving risk assessment procedures and avenues for future collaboration were also discussed. The deliberations of the meeting were also supported by a survey of participants which canvassed risk assessment approaches across the regions from which participants came. This project was initiated by Argentine Agri-Food Health and Quality National Service (SENASA, Ministry of Agriculture, Argentina), with the support of the International Life Sciences Institute (ILSI) and other partner institutions. The importance of making all possible efforts toward more integrated and harmonized regulatory oversight for GM organisms (GMOs) was strongly emphasized. This exercise showed that such harmonization is a feasible goal that would contribute to sustain a fluid trade of commodities and ultimately enhance food security. Before this can be achieved, key issues identified in this meeting will have to be addressed in the near future to enable regulatory collaboration or joint work. The authors propose that the recommendations coming out of the meeting should be used as a basis for continuing work, follow up discussions and concrete actions. PMID:25706477

Predicting consumer behavior with Web search.

PubMed

Goel, Sharad; Hofman, Jake M; Lahaie, Sébastien; Pennock, David M; Watts, Duncan J

2010-10-12

Recent work has demonstrated that Web search volume can "predict the present," meaning that it can be used to accurately track outcomes such as unemployment levels, auto and home sales, and disease prevalence in near real time. Here we show that what consumers are searching for online can also predict their collective future behavior days or even weeks in advance. Specifically we use search query volume to forecast the opening weekend box-office revenue for feature films, first-month sales of video games, and the rank of songs on the Billboard Hot 100 chart, finding in all cases that search counts are highly predictive of future outcomes. We also find that search counts generally boost the performance of baseline models fit on other publicly available data, where the boost varies from modest to dramatic, depending on the application in question. Finally, we reexamine previous work on tracking flu trends and show that, perhaps surprisingly, the utility of search data relative to a simple autoregressive model is modest. We conclude that in the absence of other data sources, or where small improvements in predictive performance are material, search queries provide a useful guide to the near future.

Predicting consumer behavior with Web search

PubMed Central

Goel, Sharad; Hofman, Jake M.; Lahaie, Sébastien; Pennock, David M.; Watts, Duncan J.

2010-01-01

Recent work has demonstrated that Web search volume can “predict the present,” meaning that it can be used to accurately track outcomes such as unemployment levels, auto and home sales, and disease prevalence in near real time. Here we show that what consumers are searching for online can also predict their collective future behavior days or even weeks in advance. Specifically we use search query volume to forecast the opening weekend box-office revenue for feature films, first-month sales of video games, and the rank of songs on the Billboard Hot 100 chart, finding in all cases that search counts are highly predictive of future outcomes. We also find that search counts generally boost the performance of baseline models fit on other publicly available data, where the boost varies from modest to dramatic, depending on the application in question. Finally, we reexamine previous work on tracking flu trends and show that, perhaps surprisingly, the utility of search data relative to a simple autoregressive model is modest. We conclude that in the absence of other data sources, or where small improvements in predictive performance are material, search queries provide a useful guide to the near future. PMID:20876140

Two decades of ART: improving on success through further research

PubMed Central

HOLMGREN, Christopher J.; FIGUEREDO, Márcia Cançado

2009-01-01

ABSTRACT Since the introduction of the Atraumatic Restorative Treatment (ART) approach over twenty years ago, more than 190 research publications have appeared. The last research agenda defining research priorities for ART was published in 1999. The objective of the present work was to review existing research in the context of future research priorities for ART. Material and Methods: An internet survey was conducted amongst those who had published on ART or were known to be working on the ART approach, to solicit their views as to areas of future ART research. Three broad categories were defined, namely: 1. Basic and laboratory research; 2. Clinical research, and, 3. Community, Public Health, Health Services Research. Results: A 31% response rate was achieved. The study identified a number of new areas of research as well as areas where additional research is required. These are expressed as recommendations for future ART research. Conclusions: The ART approach is based on a robust, reliable and ever-growing evidence base concerning its clinical applications which indicates that it is a reliable and quality treatment approach. In common with all other oral health care procedures, targeted applied research is required to improve the oral health care offered. PMID:21499666

Recent advances in Chinese archeomagnetism

NASA Astrophysics Data System (ADS)

Cai, Shuhui; Tauxe, Lisa; Paterson, Greig A.; Deng, Chenglong; Pan, Yongxin; Qin, Huafeng; Zhu, Rixiang

2017-11-01

The geomagnetic field is one of Earth’s fundamental properties with a history of 3.5 Gyr. The field, generated in Earth’s core is a window to the deep interior of Earth and may have played a key role in evolution of life on our planet. Materials on Earth’s surface that contain magnetic minerals can record information about the geomagnetic field in which they formed. Fired archeological materials (e.g., pottery, brick, and burnt clay) are favorable recorders of the field, and have been widely employed to recover geomagnetic variations over periods of hundreds to thousands of years. The longevity of Chinese civilization and the abundant nature of archeological artifacts make Chinese archeomagnetism a promising source of data. The main work of Chinese archeomagnetism was carried out in the 1980s and 90s, followed by a break of more than a decade; in the 2010s activity resumed. In this paper, we review the development of Chinese archeomagnetism, including a summary of previous work, recent progress, remaining issues and future studies with the aim of promoting an understanding of archeomagnetic work in China and to guide the way for future studies. Here, we compile published data, including some data discovered in old publications that have not yet been included in paleomagnetic databases. We also establish the first, albeit preliminary, archeomagnetic reference curves (with 42 declination / inclination pairs and 76 / 192 archeointensities) for the geomagnetic field in China (ArchInt_China.1a / ArchInt_China.1b, ArchDec_China.1, ArchInc_China.1), which can be used for global comparison of the field and regional archeomagnetic dating.

Curation and Analysis of Samples from Comet Wild-2 Returned by NASA's Stardust Mission

NASA Technical Reports Server (NTRS)

Nakamura-Messenger, Keiko; Walker, Robert M.

2015-01-01

The NASA Stardust mission returned the first direct samples of a cometary coma from comet 81P/Wild-2 in 2006. Intact capture of samples encountered at 6 km/s was enabled by the use of aerogel, an ultralow dense silica polymer. Approximately 1000 particles were captured, with micron and submicron materials distributed along mm scale length tracks. This sample collection method and the fine scale of the samples posed new challenges to the curation and cosmochemistry communities. Sample curation involved extensive, detailed photo-documentation and delicate micro-surgery to remove particles without loss from the aerogel tracks. This work had to be performed in highly clean facility to minimize the potential of contamination. JSC Curation provided samples ranging from entire tracks to micrometer-sized particles to external investigators. From the analysis perspective, distinguishing cometary materials from aerogel and identifying the potential alteration from the capture process were essential. Here, transmission electron microscopy (TEM) proved to be the key technique that would make this possible. Based on TEM work by ourselves and others, a variety of surprising findings were reported, such as the observation of high temperature phases resembling those found in meteorites, rarely intact presolar grains and scarce organic grains and submicrometer silicates. An important lesson from this experience is that curation and analysis teams must work closely together to understand the requirements and challenges of each task. The Stardust Mission also has laid important foundation to future sample returns including OSIRIS-REx and Hayabusa II and future cometary nucleus sample return missions.

Y-12 Integrated Materials Management System

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

Alspaugh, D. H.; Hickerson, T. W.

2002-06-03

The Integrated Materials Management System, when fully implemented, will provide the Y-12 National Security Complex with advanced inventory information and analysis capabilities and enable effective assessment, forecasting and management of nuclear materials, critical non-nuclear materials, and certified supplies. These capabilities will facilitate future Y-12 stockpile management work, enhance interfaces to existing National Nuclear Security Administration (NNSA) corporate-level information systems, and enable interfaces to planned NNSA systems. In the current national nuclear defense environment where, for example, weapons testing is not permitted, material managers need better, faster, more complete information about material properties and characteristics. They now must manage non-special nuclearmore » material at the same high-level they have managed SNM, and information capabilities about both must be improved. The full automation and integration of business activities related to nuclear and non-nuclear materials that will be put into effect by the Integrated Materials Management System (IMMS) will significantly improve and streamline the process of providing vital information to Y-12 and NNSA managers. This overview looks at the kinds of information improvements targeted by the IMMS project, related issues, the proposed information architecture, and the progress to date in implementing the system.« less

A Review of State-of-the-Art Separator Materials for Advanced Lithium-Based Batteries for Future Aerospace Missions

NASA Technical Reports Server (NTRS)

Bladwin, Richard S.

2009-01-01

As NASA embarks on a renewed human presence in space, safe, human-rated, electrical energy storage and power generation technologies, which will be capable of demonstrating reliable performance in a variety of unique mission environments, will be required. To address the future performance and safety requirements for the energy storage technologies that will enhance and enable future NASA Constellation Program elements and other future aerospace missions, advanced rechargeable, lithium-ion battery technology development is being pursued with an emphasis on addressing performance technology gaps between state-of-the-art capabilities and critical future mission requirements. The material attributes and related performance of a lithium-ion cell's internal separator component are critical for achieving overall optimal performance, safety and reliability. This review provides an overview of the general types, material properties and the performance and safety characteristics of current separator materials employed in lithium-ion batteries, such as those materials that are being assessed and developed for future aerospace missions.

Proceedings of the Second Noncontact Temperature Measurement Workshop

NASA Technical Reports Server (NTRS)

Hale, Robert R. (Editor)

1989-01-01

The state of the art in noncontact temperature measurement (NCTM) technology was reviewed and the NCTM requirements of microgravity materials processing community identified. The workshop included technical presentations and discussions which ranged from research on advanced concepts for temperature measurement to laboratory research and development regarding measurement principles and state-of-the-art engineering practices for NCTM methodology in commercial and industrial applications. Technical presentations were made concerning: NCTM needs as perceived by several NASA centers, recent ground-based NCT, research and development of industry, NASA, academia, and selected national laboratories, work-in-progress communication, and technical issues of the implementation of temperature measurement in the space environment to facilitate future U.S. materials science investigations.

Responsive materials for self-regulated insulin delivery.

PubMed

Wu, Weitai; Zhou, Shuiqin

2013-11-01

With diabetes mellitus becoming an important public health concern, insulin-delivery systems are attracting increasing interest from both scientific and technological researchers. This feature article covers the present state-of-the-art glucose-responsive insulin-delivery system (denoted as GRIDS), based on responsive polymer materials, a promising system for self-regulated insulin delivery. Three types of GRIDS are discussed, based on different fundamental mechanisms of glucose-recognition, with: a) glucose enzyme, b) glucose binding protein, and c) synthetic boronic acid as the glucose-sensitive component. At the end, a personal perspective on the major issues yet to be worked out in future research is provided. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis-Free Phase-Selective Gelator for Oil-Spill Remediation.

PubMed

Cui, Yaowen; Li, Mei-Chun; Wu, Qinglin; Pojman, John A; Kuroda, Daniel G

2017-10-04

A new deep eutectic solvent (DES) was developed as a phase-selective gelator for oil-spill remediation. The newly designed nonionic DES is based on a combination of an amide (N-methylacetamide) and a long chain carboxylic acid (lauric acid) and does not require any synthetic procedure besides mixing. Our studies show that the DES works as gelator by forming a gel between lauric acid and the hydrocarbon, whereas the amide serves to form the DES and dissolves in water during the gelation process. In addition, the DES material has gelation properties comparable to those considered as state-of-the-art. Overall, the newly developed material shows a promising future in oil recovery methodologies.

Hypo-Elastic Model for Lung Parenchyma

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

Freed, Alan D.; Einstein, Daniel R.

2012-03-01

A simple elastic isotropic constitutive model for the spongy tissue in lung is derived from the theory of hypoelasticity. The model is shown to exhibit a pressure dependent behavior that has been interpreted by some as indicating extensional anisotropy. In contrast, we show that this behavior arises natural from an analysis of isotropic hypoelastic invariants, and is a likely result of non-linearity, not anisotropy. The response of the model is determined analytically for several boundary value problems used for material characterization. These responses give insight into both the material behavior as well as admissible bounds on parameters. The model ismore » characterized against published experimental data for dog lung. Future work includes non-elastic model behavior.« less

Atmospheric-Pressure Plasma Jet Surface Treatment for Use in Improving Adhesion

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

Kuettner, Lindsey Ann

Atmospheric-pressure plasma jets (APPJs) are a method of plasma treatment that plays an important role in material processing and modifying surface properties of materials, especially polymers. Gas plasmas react with polymer surfaces in numerous ways such as oxidation, radical formation, degradation, and promotion of cross-linking. Because of this, gas and plasma conditions can be explored for chosen processes to maximize desired properties. The purpose of this study is to investigate plasma parameters in order to modify surface properties for improved adhesion between aluminum and epoxy substrates using two types of adhesives. The background, results to date, and future work willmore » be discussed.« less

Materials for Heated Head Automated Thermoplastic Tape Placement

NASA Technical Reports Server (NTRS)

Jensen, Brian J.; Kinney, Megan C.; Cano, Roberto J.; Grimsley, Brian W.

2012-01-01

NASA Langley Research Center (LaRC) is currently pursuing multiple paths to develop out of autoclave (OOA) polymeric composite materials and processes. Polymeric composite materials development includes the synthesis of new and/or modified thermosetting and thermoplastic matrix resins designed for specific OOA processes. OOA processes currently under investigation include vacuum bag only (VBO) prepreg/composite fabrication, resin transfer molding (RTM), vacuum assisted resin transfer molding (VARTM) and heated head automated thermoplastic tape placement (HHATP). This paper will discuss the NASA Langley HHATP facility and capabilities and recent work on characterizing thermoplastic tape quality and requirements for quality part production. Samples of three distinct versions of APC-2 (AS4/PEEK) thermoplastic dry tape were obtained from two materials vendors, TENCATE, Inc. and CYTEC Engineered Materials** (standard grade and an experimental batch). Random specimens were taken from each of these samples and subjected to photo-microscopy and surface profilometry. The CYTEC standard grade of APC-2 tape had the most voids and splits and the highest surface roughness and/or waviness. Since the APC-2 tape is composed of a thermoplastic matrix, it offers the flexibility of reprocessing to improve quality, and thereby improve final quality of HHATP laminates. Discussions will also include potential research areas and future work that is required to advance the state of the art in the HHATP process for composite fabrication.

Neutrino Flux Prediction for the NuMI Beamline

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

Soplin, Leonidas Aliaga

2016-01-01

The determination of the neutrino flux in any conventional neutrino beam presents a challenge for the current and future short and long baseline neutrino experiments. The uncertainties associated with the production and attenuation of the hadrons in the beamline materials along with those associated with the beam optics have a big effect in the flux spectrum knowledge. For experiments like MINERvA, understanding the flux is crucial since it enters directly into every neutrino-nucleus cross-sections measurements. The foundation of this work is predicting the neutrino flux at MINERvA using dedicated measurements of hadron production in hadron-nucleus collisions and incorporating in-situ MINERvAmore » data that can provide additional constraints. This work also includes the prospect for predicting the flux at other detectors like the NOvA Near detector. The procedure and conclusions of this thesis will have a big impact on future hadron production experiments and on determining the flux for the upcoming DUNE experiment.« less

Neutrino Flux Prediction for the NuMI Beamline

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

Aliaga Soplin, Leonidas

2016-01-01

The determination of the neutrino flux in any conventional neutrino beam presents a challenge for the current and future short and long baseline neutrino experiments. The uncertainties associated with the production and attenuation of the hadrons in the beamline materials along with those associated with the beam optics have a big effect in the flux spectrum knowledge. For experiments like MINERvA, understanding the flux is crucial since it enters directly into every neutrino-nucleus cross-sections measurements. The foundation of this work is predicting the neutrino flux at MINERvA using dedicated measurements of hadron production in hadron-nucleus collisions and incorporating in-situ MINERvAmore » data that can provide additional constraints. This work also includes the prospect for predicting the flux at other detectors like the NOvA Near detector. The procedure and conclusions of this thesis will have a big impact on future hadron production experiments and on determining the fl ux for the upcoming DUNE experiment.« less

Self-passivating bulk tungsten-based alloys manufactured by powder metallurgy

NASA Astrophysics Data System (ADS)

López-Ruiz, P.; Ordás, N.; Lindig, S.; Koch, F.; Iturriza, I.; García-Rosales, C.

2011-12-01

Self-passivating tungsten-based alloys are expected to provide a major safety advantage compared to pure tungsten, which is at present the main candidate material for the first wall armour of future fusion reactors. WC10Si10 alloys were manufactured by mechanical alloying (MA) in a Planetary mill and subsequent hot isostatic pressing (HIP), achieving densities above 95%. Different MA conditions were studied. After MA under optimized conditions, a core with heterogeneous microstructure was found in larger powder particles, resulting in the presence of some large W grains after HIP. Nevertheless, the obtained microstructure is significantly refined compared to previous work. First MA trials were also performed on the Si-free system WCr12Ti2.5. In this case a very homogeneous structure inside the powder particles was obtained, and a majority ternary metastable bcc phase was found, indicating that almost complete alloying occurred. Therefore, a very fine and homogeneous microstructure can be expected after HIP in future work.

The exoskeletons are here.

PubMed

Ferris, Daniel P

2009-06-09

It is a fantastic time for the field of robotic exoskeletons. Recent advances in actuators, sensors, materials, batteries, and computer processors have given new hope to creating the exoskeletons of yesteryear's science fiction. While the most common goal of an exoskeleton is to provide superhuman strength or endurance, scientists and engineers around the world are building exoskeletons with a wide range of diverse purposes. Exoskeletons can help patients with neurological disabilities improve their motor performance by providing task specific practice. Exoskeletons can help physiologists better understand how the human body works by providing a novel experimental perturbation. Exoskeletons can even help power mobile phones, music players, and other portable electronic devices by siphoning mechanical work performed during human locomotion. This special thematic series on robotic lower limb exoskeletons and orthoses includes eight papers presenting novel contributions to the field. The collective message of the papers is that robotic exoskeletons will contribute in many ways to the future benefit of humankind, and that future is not that distant.

Schottky Barrier Height of Pd/MoS2 Contact by Large Area Photoemission Spectroscopy.

PubMed

Dong, Hong; Gong, Cheng; Addou, Rafik; McDonnell, Stephen; Azcatl, Angelica; Qin, Xiaoye; Wang, Weichao; Wang, Weihua; Hinkle, Christopher L; Wallace, Robert M

2017-11-08

MoS 2 , as a model transition metal dichalcogenide, is viewed as a potential channel material in future nanoelectronic and optoelectronic devices. Minimizing the contact resistance of the metal/MoS 2 junction is critical to realizing the potential of MoS 2 -based devices. In this work, the Schottky barrier height (SBH) and the band structure of high work function Pd metal on MoS 2 have been studied by in situ X-ray photoelectron spectroscopy (XPS). The analytical spot diameter of the XPS spectrometer is about 400 μm, and the XPS signal is proportional to the detection area, so the influence of defect-mediated parallel conduction paths on the SBH does not affect the measurement. The charge redistribution by Pd on MoS 2 is detected by XPS characterization, which gives insight into metal contact physics to MoS 2 and suggests that interface engineering is necessary to lower the contact resistance for the future generation electronic applications.

Analytical applications of MIPs in diagnostic assays: future perspectives.

PubMed

Bedwell, Thomas S; Whitcombe, Michael J

2016-03-01

Many efforts have been made to produce artificial materials with biomimetic properties for applications in binding assays. Among these efforts, the technique of molecular imprinting has received much attention because of the high selectivity obtainable for molecules of interest, robustness of the produced polymers, simple and short synthesis, and excellent cost efficiency. In this review, progress in the field of molecularly imprinted sorbent assays is discussed-with a focus on work conducted from 2005 to date.

Bullet Impact Safety Study of PBX-9502

NASA Astrophysics Data System (ADS)

Ferranti, Louis

2013-06-01

A new small arms capability for performing bullet impact testing into energetic materials has recently been activated at Lawrence Livermore National Laboratory located in the High Explosives Applications Facility (HEAF). The initial capability includes 0.223, 0.30, and 0.50 testing calibers with the flexibility to add other barrels in the near future. An initial test series has been performed using the 0.50 caliber barrel shooting bullets into targets using the TATB based explosive PBX-9502 and shows an expected non-violent reaction. Future experiments to evaluate the safety of new explosive formulations to bullet impact are planned. A highlight of the new capability along with discussion of the initial experiments to date will be presented including future areas of research. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Chemical, biological, radiological, and nuclear decontamination: Recent trends and future perspective

PubMed Central

Kumar, Vinod; Goel, Rajeev; Chawla, Raman; Silambarasan, M.; Sharma, Rakesh Kumar

2010-01-01

Chemical, biological, radiological, and nuclear (CBRN) decontamination is the removal of CBRN material from equipment or humans. The objective of the decontamination is to reduce radiation burden, salvage equipment, and materials, remove loose CBRN contaminants, and fix the remaining in place in preparation for protective storage or permanent disposal work activities. Decontamination may be carried out using chemical, electrochemical, and mechanical means. Like materials, humans may also be contaminated with CBRN contamination. Changes in cellular function can occur at lower radiation doses and exposure to chemicals. At high dose, cell death may take place. Therefore, decontamination of humans at the time of emergency while generating bare minimum waste is an enormous task requiring dedication of large number of personnel and large amount of time. General principles of CBRN decontamination are discussed in this review with emphasis on radiodecontamination. PMID:21829318

High performance p-type half-Heusler thermoelectric materials

NASA Astrophysics Data System (ADS)

Yu, Junjie; Xia, Kaiyang; Zhao, Xinbing; Zhu, Tiejun

2018-03-01

Half-Heusler compounds, which possess robust mechanical strength, good high temperature thermal stability and multifaceted physical properties, have been verified as a class of promising thermoelectric materials. During the last two decades, great progress has been made in half-Heusler thermoelectrics. In this review, we summarize some representative work of p-type half-Heusler materials, the thermoelectric performance of which has been remarkably enhanced in recent years. We introduce the features of the crystal and electronic structures of half-Heusler compounds, and successful strategies for optimizing electrical and thermal transport in the p-type RFeSb (R  =  V, Nb, Ta) and MCoSb (M  =  Ti, Zr, Hf) based systems, including band engineering, the formation of solid solutions and hierarchical phonon scattering. The outlook for future research directions of half-Heusler thermoelectrics is also presented.

New perspectives in cell delivery systems for tissue regeneration: natural-derived injectable hydrogels.

PubMed

Munarin, Fabiola; Petrini, Paola; Bozzini, Sabrina; Tanzi, Maria Cristina

2012-09-27

Natural polymers, because of their biocompatibility, availability, and physico-chemical properties have been the materials of choice for the fabrication of injectable hydrogels for regenerative medicine. In particular, they are appealing materials for delivery systems and provide sustained and controlled release of drugs, proteins, gene, cells, and other active biomolecules immobilized.In this work, the use of hydrogels obtained from natural source polymers as cell delivery systems is discussed. These materials were investigated for the repair of cartilage, bone, adipose tissue, intervertebral disc, neural, and cardiac tissue. Papers from the last ten years were considered, with a particular focus on the advances of the last five years. A critical discussion is centered on new perspectives and challenges in the regeneration of specific tissues, with the aim of highlighting the limits of current systems and possible future advancements.

Degradation Mechanisms of Poly(ester urethane) Elastomer

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

Edgar, Alexander S.

This report describes literature regarding the degradation mechanisms associated with a poly(ester urethane) block copolymer, Estane® 5703 (Estane), used in conjunction with Nitroplasticizer (NP), and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane, also known as high molecular weight explosive (HMX) to produce polymer bonded explosive PBX 9501. Two principal degradation mechanisms are reported: NO2 oxidative reaction with the urethane linkage resulting in crosslinking and chain scission events, and acid catalyzed hydrolysis of the ester linkage. This report details future work regarding this PBX support system, to be conducted in late 2017 and 2018 at Engineered Materials Group (MST-7), Materials Science and Technology Division, Los Alamos Nationalmore » Laboratory. This is the first of a series of three reports on the degradation processes and trends of the support materials of PBX 9501.« less

Arsenic Adsorption from Water Using Graphene-Based Materials as Adsorbents: a Critical Review

NASA Astrophysics Data System (ADS)

Yang, Xuetong; Xia, Ling; Song, Shaoxian

2017-07-01

Adsorption is widely applied to remove arsenic from water. This paper reviewed and compared the recent progresses on the arsenic removal by adsorption using two-dimensional and three-dimensional graphene-based materials as adsorbents. Functional graphene sheet achieved the largest As(III) adsorption capacity of 138.79mg/g, while Mg-Al LDH/GO2 showed the largest As(V) adsorption capacity of 183.11mg/g. Parameters including pH, temperature, co-existing ions and loaded metal or metal oxide affected the adsorption process. The adsorption mechanisms of graphene-based materials for As(III) and As(V) could be explained by surface complexation and the electrostatic attraction, respectively. Future works are suggested to focus on regenerating of two-dimensional graphene-based adsorbents and developing the three-dimensional with large specific surface area and better adsorption performance.

Study of Material Consolidation at Higher Throughput Parameters in Selective Laser Melting of Inconel 718

NASA Technical Reports Server (NTRS)

Prater, Tracie

2016-01-01

Selective Laser Melting (SLM) is a powder bed fusion additive manufacturing process used increasingly in the aerospace industry to reduce the cost, weight, and fabrication time for complex propulsion components. SLM stands poised to revolutionize propulsion manufacturing, but there are a number of technical questions that must be addressed in order to achieve rapid, efficient fabrication and ensure adequate performance of parts manufactured using this process in safety-critical flight applications. Previous optimization studies for SLM using the Concept Laser M1 and M2 machines at NASA Marshall Space Flight Center have centered on machine default parameters. The objective of this work is to characterize the impact of higher throughput parameters (a previously unexplored region of the manufacturing operating envelope for this application) on material consolidation. In phase I of this work, density blocks were analyzed to explore the relationship between build parameters (laser power, scan speed, hatch spacing, and layer thickness) and material consolidation (assessed in terms of as-built density and porosity). Phase II additionally considers the impact of post-processing, specifically hot isostatic pressing and heat treatment, as well as deposition pattern on material consolidation in the same higher energy parameter regime considered in the phase I work. Density and microstructure represent the "first-gate" metrics for determining the adequacy of the SLM process in this parameter range and, as a critical initial indicator of material quality, will factor into a follow-on DOE that assesses the impact of these parameters on mechanical properties. This work will contribute to creating a knowledge base (understanding material behavior in all ranges of the AM equipment operating envelope) that is critical to transitioning AM from the custom low rate production sphere it currently occupies to the world of mass high rate production, where parts are fabricated at a rapid rate with confidence that they will meet or exceed all stringent functional requirements for spaceflight hardware. These studies will also provide important data on the sensitivity of material consolidation to process parameters that will inform the design and development of future flight articles using SLM.

New perspectives on potential hydrogen storage materials using high pressure.

PubMed

Song, Yang

2013-09-21

In addressing the global demand for clean and renewable energy, hydrogen stands out as the most suitable candidate for many fuel applications that require practical and efficient storage of hydrogen. Supplementary to the traditional hydrogen storage methods and materials, the high-pressure technique has emerged as a novel and unique approach to developing new potential hydrogen storage materials. Static compression of materials may result in significant changes in the structures, properties and performance that are important for hydrogen storage applications, and often lead to the formation of unprecedented phases or complexes that have profound implications for hydrogen storage. In this perspective article, 22 types of representative potential hydrogen storage materials that belong to four major classes--simple hydride, complex hydride, chemical hydride and hydrogen containing materials--were reviewed. In particular, their structures, stabilities, and pressure-induced transformations, which were reported in recent experimental works together with supporting theoretical studies, were provided. The important contextual aspects pertinent to hydrogen storage associated with novel structures and transitions were discussed. Finally, the summary of the recent advances reviewed and the insight into the future research in this direction were given.

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.

Materials towards carbon-free, emission-free and oil-free mobility: hydrogen fuel-cell vehicles--now and in the future.

PubMed

Hirose, Katsuhiko

2010-07-28

In the past, material innovation has changed society through new material-induced technologies, adding a new value to society. In the present world, engineers and scientists are expected to invent new materials to solve the global problem of climate change. For the transport sector, the challenge for material engineers is to change the oil-based world into a sustainable world. After witnessing the recent high oil price and its adverse impact on the global economy, it is time to accelerate our efforts towards this change. Industries are tackling global energy issues such as oil and CO2, as well as local environmental problems, such as NO(x) and particulate matter. Hydrogen is the most promising candidate to provide carbon-free, emission-free and oil-free mobility. As such, engineers are working very hard to bring this technology into the real society. This paper describes recent progress of vehicle technologies, as well as hydrogen-storage technologies to extend the cruise range and ensure the easiness of refuelling and requesting material scientists to collaborate with industry to fight against global warming.

Personal review and justice analysis of nursing experiences in Haiti.

PubMed

Emmott, Helen

2008-08-01

Health care providers frequently struggle to develop wise applications of theoretical knowledge. As a nurse studying traditional approaches in ethics while simultaneously volunteering in Haiti, I wrestled with the notion of justice in the midst of radical material inequities. Paul Farmer, physician and anthropologist, provides an analytic perspective for health care providers who work in poor and underserved countries by expanding the liberation theology of the 1970s to include social applications. Analyzing my past experiences in Haiti using Farmer's methodology provided insight into my successes and failures and prompted me to search for personal and professional reasons to provide care for the poor in the future. This type of reflection is essential for health care providers who work with the underserved, regardless of their religion or the country in which they work.

Synthesis, Processing, and Thermoelectric Properties of Germanium-Antimony-Tellurium Based Compounds and Alloys

NASA Astrophysics Data System (ADS)

Williams, Jared Brett

Society has become increasingly more aware of the negative impacts which nonrenewable energy sources have on the environment, and therefore the search for new and more efficient means of energy production has become an important research endeavor. Thermoelectric modules possess the unique ability to convert wasted heat into useful electrical energy via solid state processes, which could vastly improve the efficiency of a number of applications. The materials which accomplish this are typically comprised of semiconductors which exhibit high electrical conductivity, Seebeck coefficient, and thermal resistivity. Together these properties give us a gauge for the overall efficiency of the thermal to electrical energy conversion. Phase change materials are a class of materials primarily used for optical data storage in CDs, DVDs, and Blu-Ray discs. Today's state of the art phase change materials are based on alloys of GeTe and Sb2Te3. These materials have also been found to exhibit high thermoelectric efficiencies. These high efficiencies stem from their complex crystal structure and degenerate semiconducting nature. The purpose of this work was to study and engineer the thermoelectric properties of various alloys and compounds which belong to this family of materials. Specifically studied were the compounds Ge4SbTe5 and Ge17Sb2Te20. In each case various synthesis and processing strategies were implemented to increase the thermoelectric performance and better understand the fundamental electrical and thermal properties. Finally various proposals for future work on these materials are presented, all of which are based on the findings described herein.

Characterization of DWPF recycle condensate tank materials

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

Bannochie, C. J.

2015-01-01

A Defense Waste Processing Facility (DWPF) Recycle Condensate Tank (RCT) sample was delivered to the Savannah River National Laboratory (SRNL) for characterization with particular interest in the concentration of I-129, U-233, U-235, total U, and total Pu. Since a portion of Salt Batch 8 will contain DWPF recycle materials, the concentration of I-129 is important to undertand for salt batch planning purposes. The chemical and physical characterizations are also needed as input to the interpretation of future work aimed at determining the propensity of the RCT material to foam, and methods to remediate any foaming potential. According to DWPF themore » Tank Farm 2H evaporator has experienced foaming while processing DWPF recycle materials. The characterization work on the RCT samples has been completed and is reported here. The composition of the Sludge Batch 8 (SB8) RCT material is largely a low base solution of 0.2M NaNO 2 and 0.1M NaNO 3 with a small amount of formate present. Insoluble solids comprise only 0.05 wt.% of the slurry. The solids appear to be largely sludge-like solids based on elemental composition and SEM-EDS analysis. The sample contains an elevated concentration of I-129 (38x) and substantial 59% fraction of Tc-99, as compared to the incoming SB8 Tank 40 feed material. The Hg concentration is 5x, when compared to Fe, of that expected based on sludge carryover. The total U and Pu concentrations are reduced significantly, 0.536 wt.% TS and 2.42E-03 wt.% TS, respectively, with the fissile components, U-233, U-235, Pu-239, and Pu-241, an order of magnitude lower in concentration than those in the SB8 Tank 40 DWPF feed material. This report will be revised to include the foaming study requested in the TTR and outlined in the TTQAP when that work is concluded.« less

Marshall Space Flight Center - Launching the Future of Science and Exploration

NASA Technical Reports Server (NTRS)

Shivers, Alisa; Shivers, Herbert

2010-01-01

Topics include: NASA Centers around the country, launching a legacy (Explorer I), Marshall's continuing role in space exploration, MSFC history, lifting from Earth, our next mission STS 133, Space Shuttle propulsion systems, Space Shuttle facts, Space Shuttle and the International Space Station, technologies/materials originally developed for the space program, astronauts come from all over, potential future missions and example technologies, significant accomplishments, living and working in space, understanding our world, understanding worlds beyond, from exploration to innovation, inspiring the next generation, space economy, from exploration to opportunity, new program assignments, NASA's role in education, and images from deep space including a composite of a galaxy with a black hole, Sagittarius A, Pillars of Creation, and an ultra deep field

A comparative TCAD assessment of III-V channel materials for future high speed and low power logic applications

NASA Astrophysics Data System (ADS)

Gomes, U. P.; Takhar, K.; Ranjan, K.; Rathi, S.; Biswas, D.

2015-02-01

In this work, by means physics based drift-diffusion simulations, three different narrow band gap semiconductors; InAs, InSb and In0.53Ga0.47As, and their associated heterostructures have been studied for future high speed and low power logic applications. It is observed that In0.53Ga0.47As has higher immunity towards short channel effects with low DIBL and sub-threshold slope than InSb and InAs. Also it is observed that for the same device geometry InSb has the highest drive current and lower intrinsic delay but its ION/IOFF figure of merit is deteriorated due to excess leakage current.

The challenge of teaching astronomy with 0 dollars

NASA Astrophysics Data System (ADS)

Ros, Rosa Maria; García, Beatriz

2015-08-01

The training courses on Astronomy are necessary for teachers in all the countries. Normally they are more necessary in developing countries that in other ones. The challenge is to do this work without expenses. NASE, Network for Astronomy School Education, organizes courses for teachers in service and future teachers practically free of charge. The host country only pays accommodation and meals of NASE visitors. But the most interesting aspect of NASE is that presents a lot of activities to carry out in the classroom by 0 dollars using “learning by doing” methodology. After more than 60 courses in about 20 countries we can show several examples of materials generated by participants themselves during the course. With this materials they can make observations and reasoning about their observations in order to understand the astronomy concepts which appear in the curricula of different levels of formal education.Waste materials, cardboard or paper, pieces of string or wire, a stick or a CD, some milk or a drop of oil can be very useful to produce a spectrograph, a photometer, a sundial, a goniometer or a quadrant. The imagination and creativity can replace funding which are difficult to achieve in secondary and primary schools in small towns or villages. NASE is a solution for teachers. which discover that they can explain, in a simple way, complex concepts using models and observations that do not need any money!Participants in NASE courses receive instructions in order to work with NASE materials and after the courses they can find (and create) complementary materials at the NASE website, in order to continue working in the same way. We receive some contributions from some of them that we publish at our web.http:www.naseprogram.org

Atomic-scale modeling of cellulose nanocrystals

NASA Astrophysics Data System (ADS)

Wu, Xiawa

Cellulose nanocrystals (CNCs), the most abundant nanomaterials in nature, are recognized as one of the most promising candidates to meet the growing demand of green, bio-degradable and sustainable nanomaterials for future applications. CNCs draw significant interest due to their high axial elasticity and low density-elasticity ratio, both of which are extensively researched over the years. In spite of the great potential of CNCs as functional nanoparticles for nanocomposite materials, a fundamental understanding of CNC properties and their role in composite property enhancement is not available. In this work, CNCs are studied using molecular dynamics simulation method to predict their material' behaviors in the nanoscale. (a) Mechanical properties include tensile deformation in the elastic and plastic regions using molecular mechanics, molecular dynamics and nanoindentation methods. This allows comparisons between the methods and closer connectivity to experimental measurement techniques. The elastic moduli in the axial and transverse directions are obtained and the results are found to be in good agreement with previous research. The ultimate properties in plastic deformation are reported for the first time and failure mechanism are analyzed in details. (b) The thermal expansion of CNC crystals and films are studied. It is proposed that CNC film thermal expansion is due primarily to single crystal expansion and CNC-CNC interfacial motion. The relative contributions of inter- and intra-crystal responses to heating are explored. (c) Friction at cellulose-CNCs and diamond-CNCs interfaces is studied. The effects of sliding velocity, normal load, and relative angle between sliding surfaces are predicted. The Cellulose-CNC model is analyzed in terms of hydrogen bonding effect, and the diamond-CNC model compliments some of the discussion of the previous model. In summary, CNC's material properties and molecular models are both studied in this research, contributing to the present understanding of this material and leading to some possible future work.

KSC-2013-3902

NASA Image and Video Library

2013-11-07

CAPE CANAVERAL, Fla. -- Dr. Carlos Calle, senior research scientist on the Electrodynamic Dust Shield for Dust Mitigation project, works with dust fabricated for use in his experiments in the Electrostatics and Surface Physics Laboratory in the SwampWorks at NASA's Kennedy Space Center in Florida. The fabricated material is designed to mimic the dust on the lunar surface. The technology works by creating an electric field that propagates out like the ripples on a pond. This could prevent dust accumulation on spacesuits, thermal radiators, solar panels, optical instruments and view ports for future lunar and Mars exploration activities. Electrodynamic dust shield, or EDS, technology is based on concepts originally developed by NASA as early as 1967 and later by the University of Tokyo. In 2003, NASA, in collaboration with the University of Arkansas at Little Rock, started development of the EDS for dust particle removal from solar panels to be used on future missions to the moon, an asteroid or Mars. A flight experiment to expose the dust shields to the space environment currently is under development. For more information, visit: http://www.nasa.gov/content/scientists-developing-ways-to-mitigate-dust-problem-for-explorers/ Photo credit: NASA/Dan Casper

Novel Epoxy Particulate Composites for Mitigation of Insect Residue Adhesion on Future Aircraft Surfaces

NASA Technical Reports Server (NTRS)

Wohl, Christopher J.; Smith, Joseph G., Jr.; Gardner, John M.; Penner, Ronald K.; Connell, John W.; Siochi, Emilie J.

2014-01-01

Drag is reduced significantly for airflow over surfaces when laminar flow can be maintained over greater chord lengths, the distance from the leading edge of an airfoil.1 However, surface imperfections, such as chipped paint, scratches, and events that change topography on a microscopic scale can introduce airflow instabilities resulting in premature transition to turbulent flow.1 Although many of these surface imperfections can be avoided with proper maintenance, advanced materials, and advanced manufacturing practices, topographical surface anomalies arising during flight from insect impacts cannot be controlled and can influence laminar flow stability. Practical solutions to this operational challenge need to be developed for future aircraft to have full advantage of laminar flow designs that improve fuel efficiency.2 Researchers have investigated various methods to mitigate insect residue adhesion for decades.3 Although several techniques have demonstrated efficacy including mechanical scrapers, active liquid discharge systems, and sacrificial paper coatings, they have not been commercially implemented due to increased manufacturing and operational complexity, environmental impact, and weight penalties. Coatings offer a simple route for passive insect residue adhesion prevention without many of the challenges associated with maintenance of laminar flow.4 In our previous work, we determined that most commercially available materials were not effective at insect residue adhesion.5 We also identified improvements when both surface energy could be controlled by surface modifying agents and the topography could be altered through the use of micron-sized and nanometer-sized filler materials.6 In this work, these general principles were applied to an epoxy system to evaluate the behavior of the surface modifying agent, a fluorinated alkyl ether oligomer, on surface energy and insect residue adhesion properties.

Advanced High-Temperature Flexible TPS for Inflatable Aerodynamic Decelerators

NASA Technical Reports Server (NTRS)

DelCorso, Joseph A.; Cheatwood, F. McNeil; Bruce, Walter E., III; Hughes, Stephen J.; Calomino, Anthony M.

2011-01-01

Typical entry vehicle aeroshells are limited in size by the launch vehicle shroud. Inflatable aerodynamic decelerators allow larger aeroshell diameters for entry vehicles because they are not constrained to the launch vehicle shroud diameter. During launch, the hypersonic inflatable aerodynamic decelerator (HIAD) is packed in a stowed configuration. Prior to atmospheric entry, the HIAD is deployed to produce a drag device many times larger than the launch shroud diameter. The large surface area of the inflatable aeroshell provides deceleration of high-mass entry vehicles at relatively low ballistic coefficients. Even for these low ballistic coefficients there is still appreciable heating, requiring the HIAD to employ a thermal protection system (TPS). This TPS must be capable of surviving the heat pulse, and the rigors of fabrication handling, high density packing, deployment, and aerodynamic loading. This paper provides a comprehensive overview of flexible TPS tests and results, conducted over the last three years. This paper also includes an overview of each test facility, the general approach for testing flexible TPS, the thermal analysis methodology and results, and a comparison with 8-foot High Temperature Tunnel, Laser-Hardened Materials Evaluation Laboratory, and Panel Test Facility test data. Results are presented for a baseline TPS layup that can withstand a 20 W/cm2 heat flux, silicon carbide (SiC) based TPS layup, and polyimide insulator TPS layup. Recent work has focused on developing material layups expected to survive heat flux loads up to 50 W/cm2 (which is adequate for many potential applications), future work will consider concepts capable of withstanding more than 100 W/cm2 incident radiant heat flux. This paper provides an overview of the experimental setup, material layup configurations, facility conditions, and planned future flexible TPS activities.

[Technology and future ways of thinking related to work from ergonomics points of views in moments of global crisis].

PubMed

Puentes-Lagos, David E; García-Acosta, Gabriel

2012-06-01

Is it possible to establish (at short, medium and long term) future work conditions or expected work conditions for Colombian people considering upcoming work technologies? Is it possible to anticipate future work desirable work conditions for Colombian people in order to plan (foresee?) work technologies? These questions guided this research and they point to an action thesis and to a reaction one in this context of work crisis. Even though a work technology establishes where, when, how, who, who with, and using what element work is done, it also establishes certain work conditions. Besides, multiple forms of considering and deconstructing past have been created from many disciplines. However, in order to foresee or construct work technologies requires a different perspective for looking further. This research has been carried out considering other disciplines points of view regarding Future Studies and Future Thinking Studies. This research has the purpose of finding future paths for Future Thinking Studies from ergonomics point of view in this moment of global work crisis we are going through.

Sensor Amplifier for the Venus Ground Ambient

NASA Technical Reports Server (NTRS)

DelCastillo, Linda Y.; Johnson, Travis W.; Hatake, Toshiro; Mojarradi, Mohammad M.; Kolawa, Elizabeth A.

2006-01-01

Previous Venus Landers employed high temperature pressure vessels, with thermally protected electronics, to achieve successful missions, with a maximum surface lifetime of 127 minutes. Extending the operating range of electronic systems to the temperatures (480 C) and pressures (90 bar) of the Venus ground ambient would significantly increase the science return of future missions. Toward that end, the current work describes the innovative design of a sensor preamplifier, capable of working in the Venus ground ambient and designed using commercial components (thermionic vacuum tubes, wide band gap transistors, thick film resistors, advanced high temperature capacitors, and monometallic interfaces) To identify commercial components and electronic packaging materials that are capable of operation within the specified environment, a series of active devices, passive components, and packaging materials were screened for operability at 500C, assuming a 10x increase in the mission lifetime. In addition. component degradation as a function of time at 500(deg)C was evaluated. Based on the results of these preliminary evaluations, two amplifiers were developed.

Radiation Shielding Optimization on Mars

NASA Technical Reports Server (NTRS)

Slaba, Tony C.; Mertens, Chris J.; Blattnig, Steve R.

2013-01-01

Future space missions to Mars will require radiation shielding to be optimized for deep space transit and an extended stay on the surface. In deep space, increased shielding levels and material optimization will reduce the exposure from most solar particle events (SPE) but are less effective at shielding against galactic cosmic rays (GCR). On the surface, the shielding provided by the Martian atmosphere greatly reduces the exposure from most SPE, and long-term GCR exposure is a primary concern. Previous work has shown that in deep space, additional shielding of common materials such as aluminum or polyethylene does not significantly reduce the GCR exposure. In this work, it is shown that on the Martian surface, almost any amount of aluminum shielding increases exposure levels for humans. The increased exposure levels are attributed to neutron production in the shield and Martian regolith as well as the electromagnetic cascade induced in the Martian atmosphere. This result is significant for optimization of vehicle and shield designs intended for the surface of Mars.

Dimensional control of supramolecular assemblies of diacetylene-derived peptide gemini amphiphile: from spherical micelles to foamlike networks.

PubMed

Jiang, Hao; Ehlers, Martin; Hu, Xiao-Yu; Zellermann, Elio; Schmuck, Carsten

2018-05-22

Peptide amphiphiles capable of assembling into multidimensional nanostructures have attracted much attention over the past decade due to their potential applications in materials science. Herein, a novel diacetylene-derived peptide gemini amphiphile with a fluorenylmethyloxycarbonyl (Fmoc) group at the N-terminus is reported to hierarchically assemble into spherical micelles, one-dimensional nanorods, two-dimensional foamlike networks and lamellae. Solvent polarity shows a remarkable effect on the self-assembled structures by changing the balance of four weak noncovalent interactions (hydrogen-bonding, π-π stacking, hydrophobic interaction, and electrostatic repulsion). We also show the time-evolution not only from spherical micelles to helical nanofibers in aqueous solution, but also from branched wormlike micelles to foamlike networks in methanol solution. In this work, the presence of the Fmoc group plays a key role in the self-assembly process. This work provides an efficient strategy for precise morphological control, aiding the future development in materials science.

Simulation studies of nucleation of ferroelectric polarization reversal.

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

Brennecka, Geoffrey L.; Winchester, Benjamin Michael

2014-08-01

Electric field-induced reversal of spontaneous polarization is the defining characteristic of a ferroelectric material, but the process(es) and mechanism(s) associated with the initial nucleation of reverse-polarity domains are poorly understood. This report describes studies carried out using phase field modeling of LiTaO 3, a relatively simple prototype ferroelectric material, in order to explore the effects of either mechanical deformation or optically-induced free charges on nucleation and resulting domain configuration during field-induced polarization reversal. Conditions were selected to approximate as closely as feasible those of accompanying experimental work in order to provide not only support for the experimental work but alsomore » ensure that additional experimental validation of the simulations could be carried out in the future. Phase field simulations strongly support surface mechanical damage/deformation as effective for dramatically reducing the overall coercive field (Ec) via local field enhancements. Further, optically-nucleated polarization reversal appears to occur via stabilization of latent nuclei via the charge screening effects of free charges.« less

Biosensing with Paper-Based Miniaturized Printed Electrodes-A Modern Trend.

PubMed

Silveira, Célia M; Monteiro, Tiago; Almeida, Maria Gabriela

2016-09-28

From the bench-mark work on microfluidics from the Whitesides's group in 2007, paper technology has experienced significant growth, particularly regarding applications in biomedical research and clinical diagnostics. Besides the structural properties supporting microfluidics, other advantageous features of paper materials, including their versatility, disposability and low cost, show off the great potential for the development of advanced and eco-friendly analytical tools. Consequently, paper was quickly employed in the field of electrochemical sensors, being an ideal material for producing custom, tailored and miniaturized devices. Stencil-, inkjet-, or screen-printing are the preferential techniques for electrode manufacturing. Not surprisingly, we witnessed a rapid increase in the number of publications on paper based screen-printed sensors at the turn of the past decade. Among the sensing strategies, various biosensors, coupling electrochemical detectors with biomolecules, have been proposed. This work provides a critical review and a discussion on the future progress of paper technology in the context of miniaturized printed electrochemical biosensors.

Roadmap on optical metamaterials

NASA Astrophysics Data System (ADS)

Urbas, Augustine M.; Jacob, Zubin; Dal Negro, Luca; Engheta, Nader; Boardman, A. D.; Egan, P.; Khanikaev, Alexander B.; Menon, Vinod; Ferrera, Marcello; Kinsey, Nathaniel; DeVault, Clayton; Kim, Jongbum; Shalaev, Vladimir; Boltasseva, Alexandra; Valentine, Jason; Pfeiffer, Carl; Grbic, Anthony; Narimanov, Evgenii; Zhu, Linxiao; Fan, Shanhui; Alù, Andrea; Poutrina, Ekaterina; Litchinitser, Natalia M.; Noginov, Mikhail A.; MacDonald, Kevin F.; Plum, Eric; Liu, Xiaoying; Nealey, Paul F.; Kagan, Cherie R.; Murray, Christopher B.; Pawlak, Dorota A.; Smolyaninov, Igor I.; Smolyaninova, Vera N.; Chanda, Debashis

2016-09-01

Optical metamaterials have redefined how we understand light in notable ways: from strong response to optical magnetic fields, negative refraction, fast and slow light propagation in zero index and trapping structures, to flat, thin and perfect lenses. Many rules of thumb regarding optics, such as μ = 1, now have an exception, and basic formulas, such as the Fresnel equations, have been expanded. The field of metamaterials has developed strongly over the past two decades. Leveraging structured materials systems to generate tailored response to a stimulus, it has grown to encompass research in optics, electromagnetics, acoustics and, increasingly, novel hybrid material responses. This roadmap is an effort to present emerging fronts in areas of optical metamaterials that could contribute and apply to other research communities. By anchoring each contribution in current work and prospectively discussing future potential and directions, the authors are translating the work of the field in selected areas to a wider community and offering an incentive for outside researchers to engage our community where solid links do not already exist.

Biosensing with Paper-Based Miniaturized Printed Electrodes–A Modern Trend

PubMed Central

Silveira, Célia M.; Monteiro, Tiago; Almeida, Maria Gabriela

2016-01-01

From the bench-mark work on microfluidics from the Whitesides’s group in 2007, paper technology has experienced significant growth, particularly regarding applications in biomedical research and clinical diagnostics. Besides the structural properties supporting microfluidics, other advantageous features of paper materials, including their versatility, disposability and low cost, show off the great potential for the development of advanced and eco-friendly analytical tools. Consequently, paper was quickly employed in the field of electrochemical sensors, being an ideal material for producing custom, tailored and miniaturized devices. Stencil-, inkjet-, or screen-printing are the preferential techniques for electrode manufacturing. Not surprisingly, we witnessed a rapid increase in the number of publications on paper based screen-printed sensors at the turn of the past decade. Among the sensing strategies, various biosensors, coupling electrochemical detectors with biomolecules, have been proposed. This work provides a critical review and a discussion on the future progress of paper technology in the context of miniaturized printed electrochemical biosensors. PMID:27690119

A Phase Field Study of the Effect of Microstructure Grain Size Heterogeneity on Grain Growth

NASA Astrophysics Data System (ADS)

Crist, David J. D.

Recent studies conducted with sharp-interface models suggest a link between the spatial distribution of grain size variance and average grain growth rate. This relationship and its effect on grain growth rate was examined using the diffuse-interface Phase Field Method on a series of microstructures with different degrees of grain size gradation. Results from this work indicate that the average grain growth rate has a positive correlation with the average grain size dispersion for phase field simulations, confirming previous observations. It is also shown that the grain growth rate in microstructures with skewed grain size distributions is better measured through the change in the volume-weighted average grain size than statistical mean grain size. This material is based upon work supported by the National Science Foundation under Grant No. 1334283. The NSF project title is "DMREF: Real Time Control of Grain Growth in Metals" and was awarded by the Civil, Mechanical and Manufacturing Innovation division under the Designing Materials to Revolutionize and Engineer our Future (DMREF) program.

A Thermoplasticity Model for Oil Shale

DOE PAGES

White, Joshua A.; Burnham, Alan K.; Camp, David W.

2016-03-31

Several regions of the world have abundant oil shale resources, but accessing this energy supply poses a number of challenges. One particular difficulty is the thermomechanical behavior of the material. When heated to sufficient temperatures, thermal conversion of kerogen to oil, gas, and other products takes place. This alteration of microstructure leads to a complex geomechanical response. In this work, we develop a thermoplasticity model for oil shale. The model is based on critical state plasticity, a framework often used for modeling clays and soft rocks. The model described here allows for both hardening due to mechanical deformation and softeningmore » due to thermal processes. In particular, the preconsolidation pressure—defining the onset of plastic volumetric compaction—is controlled by a state variable representing the kerogen content of the material. As kerogen is converted to other phases, the material weakens and plastic compaction begins. We calibrate and compare the proposed model to a suite of high-temperature uniaxial and triaxial experiments on core samples from a pilot in situ processing operation in the Green River Formation. In conclusion, we also describe avenues for future work to improve understanding and prediction of the geomechanical behavior of oil shale operations.« less

Situating the Embodied Mind in a Landscape of Standing Affordances for Living Without Chairs: Materializing a Philosophical Worldview.

PubMed

Rietveld, Erik

2016-07-01

Sitting too much is unhealthy, but a widespread habit in many societies. Realizing behavioral change in this area is hard. Our societies promote being seated via the way its places are structured: they are filled with chairs for example. How can we make healthier environments that invite people to move around more? This article shows how philosophical research in the area of embodied/enactive cognitive science let to a built vision for the office of the future, of 2025. Multidisciplinary studio RAAAF [Rietveld Architecture-Art-Affordances] and visual artist Barbara Visser built this world without chairs, titled The End of Sitting. This large rock-like landscape integrates many affordances for standing. Affordances are the possibilities for action provided by the environment. This landscape of standing affordances allows people to work standing while being supported by the material structure of the environment. This unorthodox working landscape is both an enactive art installation and the materialization of a philosophical worldview that understands people as embodied minds situated in a landscape of affordances. It stimulates reflection on the way built environments can naturally invite more active and healthy behavior.

Fullerene C{sub 70} as a p-type donor in organic photovoltaic cells

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

Zhuang, Taojun; Wang, Xiao-Feng, E-mail: charles1976110@hotmail.com, E-mail: zrhong@ucla.edu, E-mail: kid@yz.yamagata-u.ac.jp; Sano, Takeshi

2014-09-01

Fullerenes and their derivatives have been widely used as n-type materials in organic transistor and photovoltaic devices. Though it is believed that they shall be ambipolar in nature, there have been few direct experimental proofs for that. In this work, fullerene C{sub 70}, known as an efficient acceptor, has been employed as a p-type electron donor in conjunction with 1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile as an electron acceptor in planar-heterojunction (PHJ) organic photovoltaic (OPV) cells. High fill factors (FFs) of more than 0.70 were reliably achieved with the C{sub 70} layer even up to 100 nm thick in PHJ cells, suggesting the superior potentialmore » of fullerene C{sub 70} as the p-type donor in comparison to other conventional donor materials. The optimal efficiency of these unconventional PHJ cells was 2.83% with a short-circuit current of 5.33 mA/cm{sup 2}, an open circuit voltage of 0.72 V, and a FF of 0.74. The results in this work unveil the potential of fullerene materials as donors in OPV devices, and provide alternative approaches towards future OPV applications.« less

Recent Progress on Antimonene: A New Bidimensional Material.

PubMed

Ares, Pablo; Palacios, Juan José; Abellán, Gonzalo; Gómez-Herrero, Julio; Zamora, Félix

2018-01-01

Antimonene, defined in sensu stricto as a single layer of antimony atoms, is recently the focus of numerous theoretical works predicting a variety of interesting properties and is quickly attracting the attention of the scientific community. However, what places antimonene in a different category from other 2D crystals is its strong spin-orbit coupling and a drastic evolution of its properties from the monolayer to the few-layer system. The recent isolation of this novel 2D material pushes the interest for antimonene even further. Here, a review of both theoretical predictions and experimental results is compiled. First, an account of the calculations anticipating an electronic band structure suitable for optoelectronics and thermoelectric applications in monolayer form and a topological semimetal in few-layer form is given. Second, the different approaches to produce antimonene-mechanical and liquid phase exfoliation, and epitaxial growth methods-are reviewed. In addition, this work also reports the main characterization techniques used to study this exotic material. This review provides insights for further exploring the appealing properties of antimonene and puts forward the opportunities and challenges for future applications from (opto)electronic device fabrication to biomedicine. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Earth observational research using multistage EOS-like data

NASA Technical Reports Server (NTRS)

Johannsen, C. J.; Landgrebe, D. A.

1994-01-01

This grant was funded as a part of a program in which both research and educational impact were intended. Research work under this grant is directed at the understanding and use of future hyperspectral data such as that from imaging spectrometers. Specifically, the objectives of the work were: to prepare suitable means for analyzing data from sensors which have large numbers of spectral bands, to advance the fundamental understanding of the manner in which soils and vegetative materials reflect high spectral resolution optical wavelength radiation, and to maximize the impact of the results on the educational community. Over the life of the grant, the work has thus involved basic earth science research and information system technique understanding and development in a mutually supportive way. However, during the later years it became necessary to focus the work primarily on the first and last areas, due to a steadily decreasing level of effort.

Rethinking industrial citizenship: the role and meaning of work in an age of austerity.

PubMed

Strangleman, Tim

2015-12-01

T. H. Marshall in his famous tract Citizenship and Social Class wrote briefly about what he called 'industrial citizenship', a type of belonging rooted in the workplace. Here Marshall's ideas are developed alongside a consideration of Durkheim's Professional Ethics and Civic Morals together with research material from the Guinness Company. It shows the way the Company actively sought to create 'Guinness citizenship' within its London brewery. The article draws out the ways in which the significance and potential of work based citizenship for ameliorating the ills of industrial society are clearly articulated in mid-twentieth century Britain and echo earlier neglected Durkheimian sociological ideas on work. These ideas have real potential to inform contemporary academic and policy debates about the nature of capitalism and the form and content of work now and in the future. © London School of Economics and Political Science 2015.

Evaluating Opportunities to Improve Material and Energy Impacts in Commodity Supply Chains.

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

Hanes, Rebecca J.; Carpenter, Alberta

When evaluated at the process level, next-generation technologies may be more energy and emissions intensive than current technology. However, many advanced technologies have the potential to reduce material and energy consumption in upstream or downstream processing stages. In order to fully understand the benefits and consequences of technology deployment, next-generation technologies should be evaluated in context, as part of a supply chain. This work presents the Material Flows through Industry (MFI) scenario modeling tool. The MFI tool is a cradle-to-gate linear network model of the U.S. industrial sector that can model a wide range of manufacturing scenarios, including changes inmore » production technology, increases in industrial energy efficiency, and substitution between functionally equivalent materials. The MFI tool was developed to perform supply chain scale analyses in order to quantify the impacts and benefits of next-generation technologies and materials at that scale. For the analysis presented in this paper, the MFI tool is utilized to explore a case study comparing a steel supply chain to the supply chains of several functionally equivalent materials. Several of the alternatives to the baseline steel supply chain include next-generation production technologies and materials. Results of the case study show that aluminum production scenarios can out-perform the steel supply chain by using either an advanced smelting technology or an increased aluminum recycling rate. The next-generation material supply chains do not perform as well as either aluminum or steel, but may offer additional use phase reductions in energy and emissions that are outside the scope of the MFI tool. Future work will combine results from the MFI tool with a use phase analysis.« less

Beneficial Uses Program progress report, period ending December 31, 1976. [Gamma inactivation of microorganisms in sewage sludge

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

Not Available

1977-03-01

Progress is reported on a comprehensive program to develop the necessary technologies for cost/beneficial uses of existing and future surplus radioactive materials. The major portion of the work was concentrated on the testing of the effectiveness of ..gamma.. sources for the processing of sewage sludge to inactivate enteric viruses and bacteria and the subsequent testing of the biological effects of the treated sludge when used as fertilizer or additives to animal feeds.

KSC-06pd0971

NASA Image and Video Library

2006-06-01

KENNEDY SPACE CENTER, FLA. - Inside the Space Station Processing Facility at NASA's Kennedy Space Center, an overhead crane settles the Columbus module onto a work stand. Columbus is the European Space Agency's research laboratory for the International Space Station. The module will be prepared for delivery to the space station on a future space shuttle mission. Columbus will expand the research facilities of the station and provide researchers with the ability to conduct numerous experiments in the area of life, physical and materials sciences. Photo credit: NASA/Jim Grossmann

KSC-06pd0970

NASA Image and Video Library

2006-06-01

KENNEDY SPACE CENTER, FLA. - Inside the Space Station Processing Facility at NASA's Kennedy Space Center, an overhead crane lowers the Columbus module toward a work stand. Columbus is the European Space Agency's research laboratory for the International Space Station. The module will be prepared for delivery to the space station on a future space shuttle mission. Columbus will expand the research facilities of the station and provide researchers with the ability to conduct numerous experiments in the area of life, physical and materials sciences. Photo credit: NASA/Jim Grossmann

The Factory of the Future

NASA Technical Reports Server (NTRS)

Byman, J. E.

1985-01-01

A brief history of aircraft production techniques is given. A flexible machining cell is then described. It is a computer controlled system capable of performing 4-axis machining part cleaning, dimensional inspection and materials handling functions in an unmanned environment. The cell was designed to: allow processing of similar and dissimilar parts in random order without disrupting production; allow serial (one-shipset-at-a-time) manufacturing; reduce work-in-process inventory; maximize machine utilization through remote set-up; maximize throughput and minimize labor.

Solar Surfing-Phase I and Solar Surfing - How Close to the Sun Can We Get?

NASA Technical Reports Server (NTRS)

Youngquist, Robert; Nurge, Mark; Williams, Bruce

2017-01-01

The NASA Innovative Advanced Concept (NIAC) program has been funding work at KSC on a novel coating that should allow a future spacecraft to come close to the Sun. The NIAC Symposium will be the last week of September and it is a requirement that the funded material be presented both orally and at a poster session. This DAA submission is requesting approval to go public with both the presentation and the poster.

Electromagnetic Imaging Methods for Nondestructive Evaluation Applications

PubMed Central

Deng, Yiming; Liu, Xin

2011-01-01

Electromagnetic nondestructive tests are important and widely used within the field of nondestructive evaluation (NDE). The recent advances in sensing technology, hardware and software development dedicated to imaging and image processing, and material sciences have greatly expanded the application fields, sophisticated the systems design and made the potential of electromagnetic NDE imaging seemingly unlimited. This review provides a comprehensive summary of research works on electromagnetic imaging methods for NDE applications, followed by the summary and discussions on future directions. PMID:22247693

Advanced solar receiver conceptual design study

NASA Technical Reports Server (NTRS)

Kesseli, J. B.; Lacy, D. E.

1987-01-01

High temperature solar dynamic Brayton and Stirling receivers are investigated as candidate electrical power generating systems for future LEO missions. These receivers are smaller and more efficient than conventional receivers, and they offer less structural complexity and fewer thermal stress problems. Use of the advanced Direct Absorption Storage Receiver allows many of the problems associated with working with high-volumetric-change phase-change materials to be avoided. A specific mass reduction of about 1/3 with respect to the baseline receiver has been realized.

Stress-Induced Cracking of Fluorocarbon Rubber MTL-0002 After Exposure to DS-2

DTIC Science & Technology

1993-09-01

be employed. Future Work Due to the presence of amine additives in the new SG grade automobile engine oils (13,32,33), and the increasing use of...34gasohol" fuels (gasoline and alcohol) (34), the rub- 4b ber industry has recently become concerned that hoses and seals in automobile engine environments...Materials Technology Laboratory, July 1989. 24. BARTH, E. I erhalten i’oon Pol’invliidenfluorid (PVDF) gegen Natronlauge. Kunststoffe . v. 72, 1982. p. 300

Acoustic Modeling of Lightweight Structures: A Literature Review

NASA Astrophysics Data System (ADS)

Yang, Shasha; Shen, Cheng

2017-10-01

This paper gives an overview of acoustic modeling for three kinds of typical lightweight structures including double-leaf plate system, stiffened single (or double) plate and porous material. Classical models are citied to provide frame work of theoretical modeling for acoustic property of lightweight structures; important research advances derived by our research group and other authors are introduced to describe the current state of art for acoustic research. Finally, remaining problems and future research directions are concluded and prospected briefly

Scale-Up: Improving Large Enrollment Physics Courses

NASA Astrophysics Data System (ADS)

Beichner, Robert

1999-11-01

The Student-Centered Activities for Large Enrollment University Physics (SCALE-UP) project is working to establish a learning environment that will promote increased conceptual understanding, improved problem-solving performance, and greater student satisfaction, while still maintaining class sizes of approximately 100. We are also addressing the new ABET engineering accreditation requirements for inquiry-based learning along with communication and team-oriented skills development. Results of studies of our latest classroom design, plans for future classroom space, and the current iteration of instructional materials will be discussed.

Hybrid Particle-Element Simulation of Impact on Composite Orbital Debris Shields

NASA Technical Reports Server (NTRS)

Fahrenthold, Eric P.

2004-01-01

This report describes the development of new numerical methods and new constitutive models for the simulation of hypervelocity impact effects on spacecraft. The research has included parallel implementation of the numerical methods and material models developed under the project. Validation work has included both one dimensional simulations, for comparison with exact solutions, and three dimensional simulations of published hypervelocity impact experiments. The validated formulations have been applied to simulate impact effects in a velocity and kinetic energy regime outside the capabilities of current experimental methods. The research results presented here allow for the expanded use of numerical simulation, as a complement to experimental work, in future design of spacecraft for hypervelocity impact effects.

View of Anderson working with SAME Hardware in the US Lab during Expedition 15

NASA Image and Video Library

2007-09-08

ISS015-E-27411 (8 Sept. 2007) --- NASA astronaut Clay Anderson, Expedition 15 flight engineer, works on the Smoke and Aerosol Measurement Experiment (SAME) hardware located in the Microgravity Science Glovebox (MSG) in the Destiny laboratory of the International Space Station. SAME will measure the smoke properties, or particle size distribution, of typical particles that are produced from different materials that can be found onboard station and other spacecrafts. SAME aims to test the performance of ionization smoke detectors and evaluate the performance of the photoelectric smoke detectors. The data will be used to develop a model that can predict smoke droplet growth that will be used to evaluate future smoke detection devices.

View of Anderson working with SAME Hardware in the US Lab during Expedition 15

NASA Image and Video Library

2007-09-08

ISS015-E-27425 (8 Sept. 2007) --- NASA astronaut Clay Anderson, Expedition 15 flight engineer, works on the Smoke and Aerosol Measurement Experiment (SAME) hardware located in the Microgravity Science Glovebox (MSG) in the Destiny laboratory of the International Space Station. SAME will measure the smoke properties, or particle size distribution, of typical particles that are produced from different materials that can be found onboard station and other spacecrafts. SAME aims to test the performance of ionization smoke detectors and evaluate the performance of the photoelectric smoke detectors. The data will be used to develop a model that can predict smoke droplet growth that will be used to evaluate future smoke detection devices.

Materials, Chemistry, and Simulation for Future Energy Technology.

PubMed

Aguey-Zinsou, Kondo-Francois; Wang, Da-Wei; Su, Dang-Sheng

2015-09-07

Special Issue: The Future of Energy. The science and engineering of clean energy now is becoming a multidisciplinary area, typically when new materials, chemistry, or mechanisms are met. "Trial and error" is the past. Exploration of new concepts for future clean energy can be accomplished through computer-aided materials design and reaction simulation, thanks to innovations in information technologies. This special issue, a fruit of the Energy Future Conference organized by UNSW Australia, has compiled some excellent examples of such approaches. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and superconductivity of In-doped SnTe nanostructures

DOE PAGES

Kumaravadivel, Piranavan; Pan, Grace A.; Zhou, Yu; ...

2017-07-01

In xSn 1-xTe is a time-reversal invariant candidate 3D topological superconductor derived from doping the topological crystalline insulator SnTe with indium. The ability to synthesize low-dimensional nanostructures of indium-doped SnTe is key for realizing the promise they hold in future spintronic and quantum information processing applications. But hitherto only bulk synthesized crystals and nanoplates have been used to study the superconducting properties. Here for the first time we synthesize In xSn 1-xTe nanostructures including nanowires and nanoribbons, which show superconducting transitions. In some of the lower dimensional morphologies, we observe signs of more than one superconducting transition and the absencemore » of complete superconductivity. We propose that material inhomogeneity, such as indium inhomogeneity and possible impurities from the metal catalyst, is amplified in the transport characteristics of the smaller nanostructures and is responsible for this mixed behavior. Our work represents the first demonstration of In xSn 1-xTe nanowires with the onset of superconductivity, and points to the need for improving the material quality for future applications« less

Synthesis and superconductivity of In-doped SnTe nanostructures

NASA Astrophysics Data System (ADS)

Kumaravadivel, Piranavan; Pan, Grace A.; Zhou, Yu; Xie, Yujun; Liu, Pengzi; Cha, Judy J.

2017-07-01

InxSn1-xTe is a time-reversal invariant candidate 3D topological superconductor derived from doping the topological crystalline insulator SnTe with indium. The ability to synthesize low-dimensional nanostructures of indium-doped SnTe is key for realizing the promise they hold in future spintronic and quantum information processing applications. But hitherto only bulk synthesized crystals and nanoplates have been used to study the superconducting properties. Here for the first time we synthesize InxSn1-xTe nanostructures including nanowires and nanoribbons, which show superconducting transitions. In some of the lower dimensional morphologies, we observe signs of more than one superconducting transition and the absence of complete superconductivity. We propose that material inhomogeneity, such as indium inhomogeneity and possible impurities from the metal catalyst, is amplified in the transport characteristics of the smaller nanostructures and is responsible for this mixed behavior. Our work represents the first demonstration of InxSn1-xTe nanowires with the onset of superconductivity, and points to the need for improving the material quality for future applications.

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

Xu, Gui-Liang; Chen, Zonghai; Zhong, Gui-Ming

Sodium-ion batteries are promising alternatives to lithium-ion batteries for large-scale applications. However, the low capacity and poor rate capability of existing anodes for sodium-ion batteries are bottlenecks for future developments. Here, we report a high performance nanostructured anode material for sodium-ion batteries that is fabricated by high energy ball milling to form black phosphorus/Ketjenblack–multiwalled carbon nanotubes (BPC) composite. With this strategy, the BPC composite with a high phosphorus content (70 wt %) could deliver a very high initial Coulombic efficiency (>90%) and high specific capacity with excellent cyclability at high rate of charge/discharge (~1700 mAh g–1 after 100 cycles atmore » 1.3 A g–1 based on the mass of P). In situ electrochemical impedance spectroscopy, synchrotron high energy X-ray diffraction, ex situ small/wide-angle X-ray scattering, high resolution transmission electronic microscopy, and nuclear magnetic resonance were further used to unravel its superior sodium storage performance. The scientific findings gained in this work are expected to serve as a guide for future design on high performance anode material for sodium-ion batteries.« less

Solar Energy: Non-Residential Applications and Future Technology: Student Material. First Edition.

ERIC Educational Resources Information Center

Takacs, Robert; Orsak, Charles G., Jr.

Student materials are presented for the course, Non-Residential Applications and Future Technology, one of seven core courses in Navarro College's two-year associate degree program for solar technicians. First, introductory material discusses the form and objectives of the course and ways of using the student materials. Next, readings, worksheets,…

Crashworthiness analysis using advanced material models in DYNA3D

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

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

1993-10-22

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

Organic solvent-free sugar-based transparency nanopatterning material derived from biomass for eco-friendly optical biochips using green lithography

NASA Astrophysics Data System (ADS)

Takei, Satoshi; Oshima, Akihiro; Oyama, Tomoko G.; Ito, Kenta; Sugahara, Kigenn; Kashiwakura, Miki; Kozawa, Takahiro; Tagawa, Seiichi

2014-05-01

An organic solvent-free sugar-based transparency nanopatterning material which had specific desired properties such as nanostructures of subwavelength grating and moth-eye antireflection, acceptable thermal stability of 160 °C, and low imaginary refractive index of less than 0.005 at 350-800 nm was proposed using electron beam lithography. The organic solvent-free sugar-based transparency nanopatterning material is expected for non-petroleum resources, environmental affair, safety, easiness of handling, and health of the working people, instead of the common developable process of tetramethylammonium hydroxide. 120 nm moth-eye antireflection nanopatterns images with exposure dose of 10 μC/cm2 were provided by specific process conditions of electron beam lithography. The developed sugar derivatives with hydroxyl groups and EB sensitive groups in the organic solvent-free sugar-based transparency nanopatterning material were applicable to future development of optical interface films of biology and electronics as a novel chemical design.

Li- and Mn-Rich Cathode Materials: Challenges to Commercialization

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

Zheng, Jianming; Myeong, Seungjun; Cho, Woongrae

2016-12-14

The lithium- and manganese-rich (LMR) layered structure cathode exhibit one of the highest specific energy (~900 Wh kg-1) among all the cathode materials. However, the practical applications of LMR cathodes are still hindered by several significant challenges including voltage fade, large initial capacity loss, poor rate capability and limited cycle life. Herein, we review the recent progresses and understandings on the application of LMR cathode materials from practical point of view. Several key parameters of LMR cathodes that affect the LMR/graphite full cell operation are systematically analysed. These factors include the first cycle capacity loss, voltage fade, powder tap density,more » electrode density of LMR based cathode etc. New approaches to minimize the detrimental effect of these factors are highlighted in this work. We also provided the perspectives for the future research on LMR cathode materials, focusing on addressing the fundamental problems of LMR cathodes while always keeping practical considerations in mind.« less

Graphene-based organic-inorganic hybrids with optoelectronic and magneto-optic functions (Conference Presentation)

NASA Astrophysics Data System (ADS)

Lee, Kwang-Sup; Kim, Sung-Hyun; Jung, Juhyoung; Teng, Xue-Cheng; Prabhakaran, Prem

2017-02-01

Groups around the world are pursuing optoelctronic and magneto-optic properties of graphene-based materials since they hold a lot of promise for future technologies. Quantum dot (QD) decorated graphenic nanohybrids can be candidates for demonstrating energy transfer, while magnetic nanoparticles (MNPs) on graphene give rise to interesting electronic phenomena like magneto-optical effects. Graphene containing MNPs are also good candidates for exploring quantum-hall effect. In medicine these materials have demonstrated applications in bioimaging, drug delivery, photothermal treatment and magnetic resonance imaging. A majority of groups working on QD or MNPs have focused on chemical functionalization methods for making graphene-MNP nanohybrids. We have developed a set of small molecule as well as polymeric ligands for noncovalent self-assembly of nanoparticles on graphene. The ligands contain pyrene as an anchor group for graphene and also thiol or dipamine as anchor groups for QD or MNPs. In this presentation we discuss the synthesis and characterization of these materials and outline some early results regarding exploratory device fabrication involving these materials.

Stoichiometry control in quantum dots: a viable analog to impurity doping of bulk materials.

PubMed

Luther, Joseph M; Pietryga, Jeffrey M

2013-03-26

A growing body of research indicates that the stoichiometry of compound semiconductor quantum dots (QDs) may offer control over the materials' optoelectronic properties in ways that could be invaluable in electronic devices. Quantum dots have been characterized as having a stoichiometric bulk-like core with a highly reconstructed surface of a more flexible composition, consisting essentially of ligated, weakly bound ions. As such, many efforts toward stoichiometry-based control over material properties have focused on ligand manipulation. In this issue of ACS Nano, Murray and Kagan's groups instead demonstrate control of the conductive properties of QD arrays by altering the stoichiometry via atomic infusion using a thermal evaporation technique. In this work, PbSe and PbS QD films are made to show controlled n- or p-type behavior, which is key to developing optimized QD-based electronics. In this Perspective, we discuss recent developments and the future outlook in using stoichiometry as a tool to further manipulate QD material properties in this context.

Maximal Predictability Approach for Identifying the Right Descriptors for Electrocatalytic Reactions.

PubMed

Krishnamurthy, Dilip; Sumaria, Vaidish; Viswanathan, Venkatasubramanian

2018-02-01

Density functional theory (DFT) calculations are being routinely used to identify new material candidates that approach activity near fundamental limits imposed by thermodynamics or scaling relations. DFT calculations are associated with inherent uncertainty, which limits the ability to delineate materials (distinguishability) that possess high activity. Development of error-estimation capabilities in DFT has enabled uncertainty propagation through activity-prediction models. In this work, we demonstrate an approach to propagating uncertainty through thermodynamic activity models leading to a probability distribution of the computed activity and thereby its expectation value. A new metric, prediction efficiency, is defined, which provides a quantitative measure of the ability to distinguish activity of materials and can be used to identify the optimal descriptor(s) ΔG opt . We demonstrate the framework for four important electrochemical reactions: hydrogen evolution, chlorine evolution, oxygen reduction and oxygen evolution. Future studies could utilize expected activity and prediction efficiency to significantly improve the prediction accuracy of highly active material candidates.

Development ceramic composites based on Al2O3, SiO2 and IG-017 additive

NASA Astrophysics Data System (ADS)

Kurovics, E.; Shmakova, A.; Kanev, B.; Gömze, L. A.

2017-02-01

Based on high purity alumina and quartz powders and IG-017 bio-original additives the authors have developed new ceramic composite materials for different industrial purposes. The main goal was to fine a material and morphological structures of high performance ceramic composites as frames for development complex materials for extreme consumptions in the future. For this the mixed powders of Al2O3 , SiO2 and IG-017 bio-original additive were uniaxially pressed at different compaction pressures into disc shapes and were sintered in electric kiln under air (1) and nitrogrn (2) atmosphere. The grain size distributions of the raw materials were determined by laser granulometry. There thermo-physical properties were also determined by derivatography. The prepared and sintered specimens were tested on geometrical sizes, microstructure and morphology by scanning electron microscopy, porosity and water absorption. In this work the authors present the results of their research and investigation.

A Summary on Progress in Materials Development for Advanced Lithium-ion Cells for NASA's Exploration Missions

NASA Technical Reports Server (NTRS)

Reid, Concha M.

2011-01-01

Vehicles and stand-alone power systems that enable the next generation of human missions to the moon will require energy storage systems that are safer, lighter, and more compact than current state-of-the-art (SOA) aerospace quality lithium-ion (Li-ion) batteries. NASA is developing advanced Li-ion cells to enable or enhance future human missions to Near Earth Objects, such as asteroids, planets, moons, libration points, and orbiting structures. Advanced, high-performing materials are required to provide component-level performance that can offer the required gains at the integrated cell level. Although there is still a significant amount of work yet to be done, the present state of development activities has resulted in the synthesis of promising materials that approach the ultimate performance goals. This paper on interim progress of the development efforts will present performance of materials and cell components and will elaborate on the challenges of the development activities and proposed strategies to overcome technical issues.

Oxidation Behavior of HfB2-SiC Materials in Dissociated Environments

NASA Technical Reports Server (NTRS)

Ellerby, Don; Irby, Edward; Johnson, Sylvia M.; Beckman, Sarah; Gusman, Michael; Gasch, Matthew

2002-01-01

Hafnium diboride based materials have shown promise for use in extremely high temperature applications, such as sharp leading edges on future reentry vehicles. During reentry, the oxygen and nitrogen in the atmosphere are dissociated by the shock layer ahead of the sharp leading edge such that surface reactions are determined by reactions of monatomic oxygen and nitrogen rather than O2, and N2. Simulation of the reentry environment on the ground requires the use of arc jet (plasma jet) facilities that provide monatomic species and are the closest approximation to actual flight conditions. Simple static or flowing oxidation studies under ambient pressures and atmospheres are not adequate to develop an understanding of a materials behavior in flight. Arc jet testing is required to provide the appropriate stagnation pressures, heat fluxes, enthalpies, heat loads and atmospheres encountered during flight. This work looks at the response of HfB2/SiC materials exposed to various simulated reentry environments.

Electron counting and a large family of two-dimensional semiconductors

NASA Astrophysics Data System (ADS)

Miao, Maosheng; Botana, Jorge; Zurek, Eva; Liu, Jingyao; Yang, Wen

Two-dimensional semiconductors (2DSC) are currently the focus of many studies, thanks to their novel and superior transport properties that may greatly influence future electronic devices. The potential applications of 2DSCs range from low-dimensional electronics, topological insulators and vallytronics all the way to novel photolysis. However, compared with the conventional semiconductors that are comprised of main group elements and cover a large range of band gaps and lattice constants, the choice of 2D materials is very limited. In this work, we propose and demonstrate a large family of 2DSCs, all adopting the same structure and consisting of only main group elements. Using advanced density functional calculations, we demonstrate the attainability of these materials, and show that they cover a large range of lattice constants, band gaps and band edge states, making them good candidate materials for heterojunctions. This family of two dimensional materials may be instrumental in the fabrication of 2DSC devices that may rival the currently employed 3D semiconductors.

Asbestos Exposure Assessment Database

NASA Technical Reports Server (NTRS)

Arcot, Divya K.

2010-01-01

Exposure to particular hazardous materials in a work environment is dangerous to the employees who work directly with or around the materials as well as those who come in contact with them indirectly. In order to maintain a national standard for safe working environments and protect worker health, the Occupational Safety and Health Administration (OSHA) has set forth numerous precautionary regulations. NASA has been proactive in adhering to these regulations by implementing standards which are often stricter than regulation limits and administering frequent health risk assessments. The primary objective of this project is to create the infrastructure for an Asbestos Exposure Assessment Database specific to NASA Johnson Space Center (JSC) which will compile all of the exposure assessment data into a well-organized, navigable format. The data includes Sample Types, Samples Durations, Crafts of those from whom samples were collected, Job Performance Requirements (JPR) numbers, Phased Contrast Microscopy (PCM) and Transmission Electron Microscopy (TEM) results and qualifiers, Personal Protective Equipment (PPE), and names of industrial hygienists who performed the monitoring. This database will allow NASA to provide OSHA with specific information demonstrating that JSC s work procedures are protective enough to minimize the risk of future disease from the exposures. The data has been collected by the NASA contractors Computer Sciences Corporation (CSC) and Wyle Laboratories. The personal exposure samples were collected from devices worn by laborers working at JSC and by building occupants located in asbestos-containing buildings.

NASA's Suborbital Center of Excellence - reaching young minds and crafting the future

NASA Astrophysics Data System (ADS)

Cathey, H.; Hottman, S.; Hansen, K.

The NASA Suborbital Center of Excellence is charting new territory. From an idea to promote science and engineering education and outreach, the Suborbital Center of Excellence is working toward the objective of increasing numbers of college graduates choosing a career in suborbital programs. Approaches to excite university students to want to pursue these careers through relevant and useful work experiences will be highlighted. Suborbital platforms include balloons, sounding rockets, research aircraft (manned and remotely piloted vehicles) and small satellites. Key components of this are the Suborbital Center of Excellence co-op program and the support of Engineering ``Capstone'' projects. A number of these projects and programs have been supported during the past year. Highlights of these student hands-on learning experiences will be presented. The projects have included diverse projects ranging from work on a power beaming demonstration and autonomous aircraft control logic to the development of light weight pressure vessels for balloon flights based on ULDB spin-off technology, and balloon drop sonde development. Preparing these future Scientists and Engineers involves the investment of time, energy, and resources. The Suborbital Center of Excellence is uniquely positioned to do this. Future programs and initiatives will be presented. The Suborbital Center of Excellence is evolving, meeting the needs to promote science and engineering education and outreach. Educational outreach initiatives for young children to university students will also be presented. These include hands-on experiments, demonstrations, and suborbital educational materials.

The Natural Hospital Environment: a Socio-Technical-Material perspective.

PubMed

Fernando, Juanita; Dawson, Linda

2014-02-01

This paper introduces two concepts into analyses of information security and hospital-based information systems-- a Socio-Technical-Material theoretical framework and the Natural Hospital Environment. The research is grounded in a review of pertinent literature with previously published Australian (Victoria) case study data to analyse the way clinicians work with privacy and security in their work. The analysis was sorted into thematic categories, providing the basis for the Natural Hospital Environment and Socio-Technical-Material framework theories discussed here. Natural Hospital Environments feature inadequate yet pervasive computer use, aural privacy shortcomings, shared workspace, meagre budgets, complex regulation that hinders training outcomes and out-dated infrastructure and are highly interruptive. Working collaboratively in many cases, participants found ways to avoid or misuse security tools, such as passwords or screensavers for patient care. Workgroup infrastructure was old, architecturally limited, haphazard in some instances, and was less useful than paper handover sheets to ensure the quality of patient care outcomes. Despite valiant efforts by some participants, they were unable to control factors influencing the privacy of patient health information in public hospital settings. Future improvements to hospital-based organisational frameworks for e-health can only be made when there is an improved understanding of the Socio-Technical-Material theoretical framework and Natural Hospital Environment contexts. Aspects within control of clinicians and administrators can be addressed directly although some others are beyond their control. An understanding and acknowledgement of these issues will benefit the management and planning of improved and secure hospital settings. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Utilization of agricultural and forest industry waste and residues in natural fiber-polymer composites: A review.

PubMed

Väisänen, Taneli; Haapala, Antti; Lappalainen, Reijo; Tomppo, Laura

2016-08-01

Natural fiber-polymer composites (NFPCs) are becoming increasingly utilized in a wide variety of applications because they represent an ecological and inexpensive alternative to conventional petroleum-derived materials. On the other hand, considerable amounts of organic waste and residues from the industrial and agricultural processes are still underutilized as low-value energy sources. Organic materials are commonly disposed of or subjected to the traditional waste management methods, such as landfilling, composting or anaerobic digestion. The use of organic waste and residue materials in NFPCs represents an ecologically friendly and a substantially higher value alternative. This is a comprehensive review examining how organic waste and residues could be utilized in the future as reinforcements or additives for NFPCs from the perspective of the recently reported work in this field. Copyright © 2016 Elsevier Ltd. All rights reserved.

The origin of the residual conductivity of GaN films on ferroelectric materials

NASA Astrophysics Data System (ADS)

Lee, Kyoung-Keun; Cai, Zhuhua; Ziemer, Katherine; Doolittle, William Alan

2009-08-01

In this paper, the origin of the conductivity of GaN films grown on ferroelectric materials was investigated using XPS, AES, and XRD analysis tools. Depth profiles confirmed the existence of impurities in the GaN film originating from the substrates. Bonding energy analysis from XPS and AES verified that oxygen impurities from the substrates were the dominant origin of the conductivity of the GaN film. Furthermore, Ga-rich GaN films have a greater chance of enhancing diffusion of lithium oxide from the substrates, resulting in more substrate phase separation and a wider inter-mixed region confirmed by XRD. Therefore, the direct GaN film growth on ferroelectric materials causes impurity diffusion from the substrates, resulting in highly conductive GaN films. Future work needs to develop non-conductive buffer layers for impurity suppression in order to obtain highly resistive GaN films.

Electronic structure of CdSe-ZnS 2D nanoplatelets

NASA Astrophysics Data System (ADS)

Cruguel, Hervé; Livache, Clément; Martinez, Bertille; Pedetti, Silvia; Pierucci, Debora; Izquierdo, Eva; Dufour, Marion; Ithurria, Sandrine; Aubin, Hervé; Ouerghi, Abdelkarim; Lacaze, Emmanuelle; Silly, Mathieu G.; Dubertret, Benoit; Lhuillier, Emmanuel

2017-04-01

Among colloidal nanocrystals, 2D nanoplatelets (NPLs) made of cadmium chalcogenides have led to especially well controlled optical features. However, the growth of core shell heterostructures has so far been mostly focused on CdS shells, while more confined materials will be more promising to decouple the emitting quantum states of the core from their external environment. Using k.p simulation, we demonstrate that a ZnS shell reduces by a factor 10 the leakage of the wavefunction into the surrounding medium. Using X-ray photoemission (XPS), we confirm that the CdSe active layer is indeed unoxidized. Finally, we build an effective electronic spectrum for these CdSe/ZnS NPLs on an absolute energy scale which is a critical set of parameters for the future integration of this material into optoelectronic devices. We determine the work function (WF) to be 4.47 eV while the material is behaving as an n-type semiconductor.

The Development of Metal Oxide Chemical Sensing Nanostructures

NASA Technical Reports Server (NTRS)

Hunter, G. W.; VanderWal,R. L.; Xu, J. C.; Evans, L. J.; Berger, G. M.; Kulis, M. J.

2008-01-01

This paper discusses sensor development based on metal oxide nanostructures and microsystems technology. While nanostructures such as nanowires show significant potential as enabling materials for chemical sensors, a number of significant technical challenges remain. This paper discusses development to address each of these technical barriers: 1) Improved contact and integration of the nanostructured materials with microsystems in a sensor structure; 2) Control of nanostructure crystallinity to allow control of the detection mechanism; and 3) Widening the range of gases that can be detected by fabricating multiple nanostructured materials. A sensor structure composed of three nanostructured oxides aligned on a single microsensor has been fabricated and tested. Results of this testing are discussed and future development approaches are suggested. It is concluded that while this work lays the foundation for further development, these are the beginning steps towards realization of repeatable, controlled sensor systems using oxide based nanostructures.

System definition study of deployable, non-metallic space structures

NASA Technical Reports Server (NTRS)

Stimler, F. J.

1984-01-01

The state of the art for nonmetallic materials and fabrication techniques suitable for future space structures are summarized. Typical subsystems and systems of interest to the space community that are reviewed include: (1) inflatable/rigidized space hangar; (2) flexible/storable acoustic barrier; (3) deployable fabric bulkhead in a space habitat; (4) extendible tunnel for soft docking; (5) deployable space recovery/re-entry systems for personnel or materials; (6) a manned habitat for a space station; (7) storage enclosures external to the space station habitat; (8) attachable work stations; and (9) safe haven structures. Performance parameters examined include micrometeoroid protection; leakage rate prediction and control; rigidization of flexible structures in the space environment; flammability and offgassing; lifetime for nonmetallic materials; crack propagation prevention; and the effects of atomic oxygen and space debris. An expandable airlock for shuttle flight experiments and potential tethered experiments from shuttle are discussed.

Characterising encapsulated nuclear waste using cosmic-ray muon tomography

NASA Astrophysics Data System (ADS)

Clarkson, A.; Hamilton, D. J.; Hoek, M.; Ireland, D. G.; Johnstone, J. R.; Kaiser, R.; Keri, T.; Lumsden, S.; Mahon, D. F.; McKinnon, B.; Murray, M.; Nutbeam-Tuffs, S.; Shearer, C.; Yang, G.; Zimmerman, C.

2015-03-01

Tomographic imaging techniques using the Coulomb scattering of cosmic-ray muons have been shown previously to successfully identify and characterise low- and high-Z materials within an air matrix using a prototype scintillating-fibre tracker system. Those studies were performed as the first in a series to assess the feasibility of this technology and image reconstruction techniques in characterising the potential high-Z contents of legacy nuclear waste containers for the U.K. Nuclear Industry. The present work continues the feasibility study and presents the first images reconstructed from experimental data collected using this small-scale prototype system of low- and high-Z materials encapsulated within a concrete-filled stainless-steel container. Clear discrimination is observed between the thick steel casing, the concrete matrix and the sample materials assayed. These reconstructed objects are presented and discussed in detail alongside the implications for future industrial scenarios.

Aqueous gating of van der Waals materials on bilayer nanopaper.

PubMed

Bao, Wenzhong; Fang, Zhiqiang; Wan, Jiayu; Dai, Jiaqi; Zhu, Hongli; Han, Xiaogang; Yang, Xiaofeng; Preston, Colin; Hu, Liangbing

2014-10-28

In this work, we report transistors made of van der Waals materials on a mesoporous paper with a smooth nanoscale surface. The aqueous transistor has a novel planar structure with source, drain, and gate electrodes on the same surface of the paper, while the mesoporous paper is used as an electrolyte reservoir. These transistors are enabled by an all-cellulose paper with nanofibrillated cellulose (NFC) on the top surface that leads to an excellent surface smoothness, while the rest of the microsized cellulose fibers can absorb electrolyte effectively. Based on two-dimensional van der Waals materials, including MoS2 and graphene, we demonstrate high-performance transistors with a large on-off ratio and low subthreshold swing. Such planar transistors with absorbed electrolyte gating can be used as sensors integrated with other components to form paper microfluidic systems. This study is significant for future paper-based electronics and biosensors.

Validation of material point method for soil fluidisation analysis

NASA Astrophysics Data System (ADS)

Bolognin, Marco; Martinelli, Mario; Bakker, Klaas J.; Jonkman, Sebastiaan N.

2017-06-01

The main aim of this paper is to describe and analyse the modelling of vertical column tests that undergo fluidisation by the application of a hydraulic gradient. A recent advancement of the material point method (MPM), allows studying both stationary and non-stationary fluid flow while interacting with the solid phase. The fluidisation initiation and post-fluidisation processes of the soil will be investigated with an advanced MPM formulation (Double Point) in which the behavior of the solid and the liquid phase is evaluated separately, assigning to each of them a set of material points (MPs). The result of these simulations are compared to analytic solutions and measurements from laboratory experiments. This work is used as a benchmark test for the MPM double point formulation in the Anura3D software and to verify the feasibility of the software for possible future engineering applications.

LIFE Materials: Thermomechanical Effects Volume 5 - Part I

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

Caro, M; DeMange, P; Marian, J

2009-05-07

Improved fuel performance is a key issue in the current Laser Inertial-Confinement Fusion-Fission Energy (LIFE) engine design. LIFE is a fusion-fission engine composed of a {approx}40-tons fuel blanket surrounding a pulsed fusion neutron source. Fusion neutrons get multiplied and moderated in a Beryllium blanket before penetrating the subcritical fission blanket. The fuel in the blanket is composed of millions of fuel pebbles, and can in principle be burned to over 99% FIMA without refueling or reprocessing. This report contains the following chapters: Chapter A: LIFE Requirements for Materials -- LIFE Fuel; Chapter B: Summary of Existing Knowledge; Chapter C: Identificationmore » of Gaps in Knowledge & Vulnerabilities; and Chapter D: Strategy and Future Work.« less

A study of gamma-ray and neutron radiation in the interaction of a 2 MeV proton beam with various materials.

PubMed

Kasatov, D; Makarov, A; Shchudlo, I; Taskaev, S

2015-12-01

Epithermal neutron source based on a tandem accelerator with vacuum insulation and lithium target has been proposed, developed and operated in Budker Institute of Nuclear Physics. The source is regarded as a prototype of a future compact device suitable for carrying out BNCT in oncology centers. In this work the measurements of gamma-ray and neutron radiation are presented for the interaction of a 2 MeV proton beam with various materials (Li, C, F, Al, V, Ti, Cu, Mo, stainless steel, and Ta). The obtained results enabled the optimization of the neutron-generating target and the high energy beam transportation path. Copyright © 2015 Elsevier Ltd. All rights reserved.

Trends in biotechnological production of fuel ethanol from different feedstocks.

PubMed

Sánchez, Oscar J; Cardona, Carlos A

2008-09-01

Present work deals with the biotechnological production of fuel ethanol from different raw materials. The different technologies for producing fuel ethanol from sucrose-containing feedstocks (mainly sugar cane), starchy materials and lignocellulosic biomass are described along with the major research trends for improving them. The complexity of the biomass processing is recognized through the analysis of the different stages involved in the conversion of lignocellulosic complex into fermentable sugars. The features of fermentation processes for the three groups of studied feedstocks are discussed. Comparative indexes for the three major types of feedstocks for fuel ethanol production are presented. Finally, some concluding considerations on current research and future tendencies in the production of fuel ethanol regarding the pretreatment and biological conversion of the feedstocks are presented.

Generation and Evaluation of Lunar Dust Adhesion Mitigating Materials

NASA Technical Reports Server (NTRS)

Wohl, Christopher J.; Connell, John W.; Lin, Yi; Belcher, Marcus A.; Palmieri, Frank L.

2011-01-01

Particulate contamination is of concern in a variety of environments. This issue is especially important in confined spaces with highly controlled atmospheres such as space exploration vehicles involved in extraterrestrial surface missions. Lunar dust was a significant challenge for the Apollo astronauts and will be of greater concern for longer duration, future missions. Passive mitigation strategies, those not requiring external energy, may decrease some of these concerns, and have been investigated in this work. A myriad of approaches to modify the surface chemistry and topography of a variety of substrates was investigated. These involved generation of novel materials, photolithographic techniques, and other template approaches. Additionally, single particle and multiple particle methods to quantitatively evaluate the particle-substrate adhesion interactions were developed.

Research highlights: printing the future of microfabrication.

PubMed

Tseng, Peter; Murray, Coleman; Kim, Donghyuk; Di Carlo, Dino

2014-05-07

In this issue we highlight emerging microfabrication approaches suitable for microfluidic systems with a focus on "additive manufacturing" processes (i.e. printing). In parallel with the now-wider availability of low cost consumer-grade 3D printers (as evidenced by at least three brands of 3D printers for sale in a recent visit to an electronics store in Akihabara, Tokyo), commercial-grade 3D printers are ramping to higher and higher resolution with new capabilities, such as printing of multiple materials of different transparency, and with different mechanical and electrical properties. We highlight new work showing that 3D printing (stereolithography approaches in particular) has now risen as a viable technology to print whole microfluidic devices. Printing on 2D surfaces such as paper is an everyday experience, and has been used widely in analytical chemistry for printing conductive materials on paper strips for glucose and other electrochemical sensors. We highlight recent work using electrodes printed on paper for digital microfluidic droplet actuation. Finally, we highlight recent work in which printing of membrane-bound droplets that interconnect through bilayer membranes may open up an entirely new approach to microfluidic manufacturing of soft devices that mimic physiological systems.

Review of Manganese Processing for Production of TRIP/TWIP Steels, Part 1: Current Practice and Processing Fundamentals

NASA Astrophysics Data System (ADS)

Elliott, R.; Coley, K.; Mostaghel, S.; Barati, M.

2018-02-01

The increasing demand for high-performance steel alloys has led to development of transformation-induced plasticity (TRIP) and twinning-induced plasticity (TWIP) alloys over the past three decades. These alloys offer exceptional combinations of high tensile strength and ductility. Thus, the mechanical behavior of these alloys has been a subject of significant work in recent years. However, the challenge of economically providing Mn in the quantity and purity required by these alloys has received considerably less attention. To enable commercial implementation of ultrahigh-Mn alloys, it is desirable to lower the high material costs associated with their production. Therefore, the present work reviews Mn processing routes in the context of the chemical requirements of these alloys. The aim of this review is to assess the current state of the art regarding reduction of manganese ores and provide a comprehensive reference for researchers working to mitigate material processing costs associated with Mn production. The review is presented in two parts: Part 1 introduces TRIP and TWIP alloys, current industrial practice, and pertinent thermodynamic fundamentals; Part 2 addresses available literature regarding reduction of Mn ores and oxides, and seeks to identify opportunities for future process development.

Advanced Electrical Materials and Components Development: An Update

NASA Technical Reports Server (NTRS)

Schwarze, Gene E.

2005-01-01

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

Synthesis and Characterization of 2-D Materials

NASA Astrophysics Data System (ADS)

Pazos, S.; Sahoo, P.; Afaneh, T.; Rodriguez Gutierrez, H.

Atomically thin transition-metal dichacogenides (TMD), graphene, and boron nitride (BN) are two-dimensional materials where the charge carriers (electrons and holes) are confined to move in a plane. They exhibit distinctive optoelectronic properties compared to their bulk layered counterparts. When combined into heterostructures, these materials open more possibilities in terms of new properties and device functionality. In this work, WSe2 and graphene were grown using Chemical Vapor Deposition (CVD) and Physical Vapor Deposition (PVD) techniques. The quality and morphology of each material was checked using Raman, Photoluminescence Spectroscopy, and Scanning Electron Microscopy. Graphene had been successfully grown homogenously, characterized, and transferred from copper to silicon dioxide substrates; these films will be used in future studies to build 2-D devices. Different morphologies of WSe2 2-D islands were successfully grown on SiO2 substrates. Depending on the synthesis conditions, the material on each sample had single layer, double layer, and multi-layer areas. A variety of 2-D morphologies were also observed in the 2-D islands. This project is supported by the NSF REU Grant #1560090 and NSF Grant #DMR-1557434.

Materials R&D-student internships

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

Thompson, R.B.; Jiles, D.C.; Chumbley, L.S.

1995-05-01

This program has as an objective the conduct of programmatic research for the Advanced Industrial Concepts Materials Program while training minority graduate students in the process. Well-known demographics indicate that minorities will constitute an increasing fraction of our future work force. Consequently, efforts have been initiated to increase the fraction of minorities and women who choose technical career paths. Included are a wide ranging set of programs beginning with pre-school education, progressing through efforts to retain students in technical paths in grades K-12 and undergraduate education, and ending with encouraging graduate education. The Materials R & D - Student Internshipsmore » is a unique approach in the latter category. Here, we have focused on a particular area of applied materials research, the Advanced Industrial Concepts Materials Program. Our goal, then, is to educate minority graduate students in the context of this program. The Ames Laboratory was selected as a site for this pilot project since it is a DOE national laboratory, located on the campus of a major research university, which includes in its research interests programs with a strong technological flavor.« less

The importance of pedagogical content knowledge in curriculum development for illumination engineering

NASA Astrophysics Data System (ADS)

Pompea, Stephen M.; Walker, Constance E.

2017-08-01

An understanding of pedagogical content knowledge (PCK) and educative materials has been critical to our teaching programs in illumination engineering. We will discuss the PCK basis of a number of innovative curriculum efforts at the National Optical Astronomy and how we develop "educative materials" that improve educator content knowledge, pedagogical knowledge, and contextual knowledge. We also describe the process and team approach required to create these "educative materials." The foundation of our work at NOAO were two previous projects at the NASA Classroom of the Future. These projects created educative curricular materials with sophisticated science content integrated with a deep, authentic understanding of science process. Additional curricula with these attributes were developed at NOAO for the NSF-sponsored Hands-On Optics project (SPIE, OSA, and NOAO), for the citizen science project Globe at Night (NOAO), and for the Quality Lighting Teaching Kits (NOAO, International Astronomical Union, OSA Foundation, SPIE, CIE, and the International Dark Sky Association). These projects all strove to create educative instructional materials that can enhance the pedagogical content knowledge of educators.

Modulation of surface flatness and van der Waals bonding of two-dimensional materials to reduce contact resistance.

NASA Astrophysics Data System (ADS)

Yue, Dewu; Yoo, Won Jong

Despite that the novel quantum mechanical properties of two-dimension (2D) materials are well explored theoretically, their electronic performance is limited by the contact resistance of the metallic interface and therefore their inherent novel properties are rarely realized experimentally. In this study, we demonstrate that we can largely reduce the contact resistance induced between metal and 2D materials, by controlling the surface condition of 2D materials, eg. surface flatness and van der Waals bonding. To induce the number of more effective carrier conducting modes, we engineer the surface roughness and dangling bonds of the 2D interface in contact with metal. As a result, electrical contact resistance of the metal interface is significantly reduced and carrier mobility in the device level is enhanced correspondingly. This work was supported by the Global Research Laboratory and Global Frontier R&D Programs at the Center for Hybrid Interface Materials, both funded by the Ministry of Science, ICT & Future Planning via the National Research Foundation of Korea (NRF).

Physico-Chemical Alternatives in Lignocellulosic Materials in Relation to the Kind of Component for Fermenting Purposes

PubMed Central

Coz, Alberto; Llano, Tamara; Cifrián, Eva; Viguri, Javier; Maican, Edmond; Sixta, Herbert

2016-01-01

The complete bioconversion of the carbohydrate fraction is of great importance for a lignocellulosic-based biorefinery. However, due to the structure of the lignocellulosic materials, and depending basically on the main parameters within the pretreatment steps, numerous byproducts are generated and they act as inhibitors in the fermentation operations. In this sense, the impact of inhibitory compounds derived from lignocellulosic materials is one of the major challenges for a sustainable biomass-to-biofuel and -bioproduct industry. In order to minimise the negative effects of these compounds, numerous methodologies have been tested including physical, chemical, and biological processes. The main physical and chemical treatments have been studied in this work in relation to the lignocellulosic material and the inhibitor in order to point out the best mechanisms for fermenting purposes. In addition, special attention has been made in the case of lignocellulosic hydrolysates obtained by chemical processes with SO2, due to the complex matrix of these materials and the increase in these methodologies in future biorefinery markets. Recommendations of different detoxification methods have been given. PMID:28773700

Standardization of shape memory alloy test methods toward certification of aerospace applications

NASA Astrophysics Data System (ADS)

Hartl, D. J.; Mabe, J. H.; Benafan, O.; Coda, A.; Conduit, B.; Padan, R.; Van Doren, B.

2015-08-01

The response of shape memory alloy (SMA) components employed as actuators has enabled a number of adaptable aero-structural solutions. However, there are currently no industry or government-accepted standardized test methods for SMA materials when used as actuators and their transition to commercialization and production has been hindered. This brief fast track communication introduces to the community a recently initiated collaborative and pre-competitive SMA specification and standardization effort that is expected to deliver the first ever regulatory agency-accepted material specification and test standards for SMA as employed as actuators for commercial and military aviation applications. In the first phase of this effort, described herein, the team is working to review past efforts and deliver a set of agreed-upon properties to be included in future material certification specifications as well as the associated experiments needed to obtain them in a consistent manner. Essential for the success of this project is the participation and input from a number of organizations and individuals, including engineers and designers working in materials and processing development, application design, SMA component fabrication, and testing at the material, component, and system level. Going forward, strong consensus among this diverse body of participants and the SMA research community at large is needed to advance standardization concepts for universal adoption by the greater aerospace community and especially regulatory bodies. It is expected that the development and release of public standards will be done in collaboration with an established standards development organization.

PREFACE: International Conference on Structural Nano Composites (NANOSTRUC 2012)

NASA Astrophysics Data System (ADS)

Njuguna, James

2012-09-01

Dear Colleagues It is a great pleasure to welcome you to NanoStruc2012 at Cranfield University. The purpose of the 2012 International Conference on Structural Nano Composites (NanoStruc2012) is to promote activities in various areas of materials and structures by providing a forum for exchange of ideas, presentation of technical achievements and discussion of future directions. NanoStruc brings together an international community of experts to discuss the state-of-the-art, new research results, perspectives of future developments, and innovative applications relevant to structural materials, engineering structures, nanocomposites, modelling and simulations, and their related application areas. The conference is split in 7 panel sessions, Metallic Nanocomposites and Coatings, Silica based Nanocomposites, safty of Nanomaterials, Carboin based Nanocomposites, Multscale Modelling, Bio materials and Application of Nanomaterials. All accepted Papers will be published in the IOP Conference Series: Materials Science and Engineering (MSE), and included in the NanoStruc online digital library. The abstracts will be indexed in Scopus, Compedex, Inspec, INIS (International Nuclear Information System), Chemical Abstracts, NASA Astrophysics Data System and Polymer Library. Before ending this message, I would like to acknowledge the hard work, professional skills and efficiency of the team which ensured the general organisation. As a conclusion, I would like to Welcome you to the Nanostruc2012 and wish you a stimulating Conference and a wonderful time. On behalf of the scientific committee, Signature James Njuguna Conference Chair The PDF of this preface also contains committee listings and associates logos.

Present investigations of radioactive raw materials by the Geological Survey and a recommended program for future work

USGS Publications Warehouse

Butler, A.P.; Stead, F.W.

1947-01-01

The Geological Survey's program of investigation of radioactive raw materials is presented herewith under present investigations, plans for future investigations, plan of operation, and cost of operation. This report was prepared at the request of the Atomic Energy Commission. Present investigations are summarized to show the scope of the present Trace Elements program, grouping individual projects into related types of investigations. Plans for future investigations on an expanded scale are outlined. These should provide sufficient data and knowledge of the occurrence and availability of uranium, thorium, and related elements, to permit a more complete evaluation of domestic resources. Reconnaissance projects are designed to discover possible new sources of uranium and thorium and to select areas and materials warranting further investigation. Typical projects leading to the estimation of reserves are the investigation of the carnotite ores of the Colorado Plateau by geologic mapping, exploratory drilling, and related research, and investigation of asphaltic sandstone in Emery County, Utah. Extensive research will be undertaken to establish the principles governing the geological and geochemical relations of uranium, thorium, and associated elements as an essential guide in appraising domestic resources. Particular emphasis will be placed on phosphatic rocks and black shales which offer ultimate resources of uranium far greater than carnotite ores. All the foregoing investigations will be accompanied by chemical, gephysical, and mineralogical research and analytical work. Under plan of operation is discussed the organization of the Trace Elements Unit, space requirements for laboratory and office, the scheduling of investigations, and other related problems. The proposed scheduling of work calls for approximately 109, 173, and 203 man years in fiscal years 1948, 1949, and 1950 respectively. Definite plans have been formulated only for the next three fiscal years, by which time it is assumed the program will reach stable proportions or can be altered as experience dictates. Under cost of operation is set forth the funds available in fiscal year 1947, the status of funds transferred from Atomic Services (14-217/80920), and funds necessary in succeeding fiscal years. The estimate for fiscal year 1948 inclues a non-recurring item of $1,025,000 for establishing adequate laboratories for chemical, physical, spectrographic and mineralogic research and analytical work. The total funds required in fiscal years 1948, 1949, and 1950 to support the proposed program will be $2,440,000, $2,161,000 and $2,198,000 respectively. The Geological survey anticipates contributing from its appropriation in fiscal years 1948, 1949 and 1950 approximately $243,000, $350,000, and $400,000 respectively; the balance of the necessary funds to be contributed by the Atomic Energy Commission in fiscal years 1948, 1949, and 1950 will be approximately $2,196,900, $1,811,000, and $1,798,000 respectively.

Integrating Copper Nanowire Electrodes for Low Temperature Perovskite Photovoltaic Cells

NASA Astrophysics Data System (ADS)

Mankowski, Trent

Recent advances in third generation photovoltaics, particularly the rapid increase in perovskite power conversion efficiencies, may provide a cheap alternative to silicon solar cells in the near future. A key component to these devices is the transparent front electrode, and in the case of Dye Sensitized Solar Cells, it is the most expensive part. A lightweight, cost-effective, robust, and easy-to-fabricate new generation TCE is required to enable competition with silicon. Indium Tin Oxide, commonly used in touchscreen devices, Organic Light Emitting Diodes (OLEDs), and thin film photovoltaics, is widely used and commonly referred to as the industry standard. As the global supply of indium decreases and the demand for this TCE increases, a similar alternative TCE is required to accompany the next generation solar cells that promise energy with lighter and significantly cheaper modules. This alternative TCE needs to provide similar sheet resistance and optical transmittance to ITO, while also being mechanically and chemically robust. The work in this thesis begins with an exploration of several synthesized ITO replacement materials, such as copper nanowires, conductive polymer PEDOT:PSS, zinc oxide thin films, reduced graphene oxide and combinations of the above. A guiding philosophy to this work was prioritizing cheap, easy deposition methods and overall scalability. Shortcomings of these TCEs were investigated and different materials were hybridized to take advantage of each layers strengths for development of an ideal ITO replacement. For CuNW-based composite electrodes, 85% optical transmittance and 25 O/sq were observed and characterized to understand the underlying mechanisms for optimization. The second half of this work is an examination of many different perovskite synthesis methods first to achieve highest performance, and then to integrate compatible methods with our CuNW TCEs. Several literature methods investigated were irreproducible, and those that were successful posed difficulties integrating with CuNW-based TCEs. Those shortcomings are discussed, and how future work might skirt the issues revealed here to produce a very low cost, high performance perovskite solar cell.

Development of lead zirconate titanate cantilevers on the micrometer length scale

NASA Astrophysics Data System (ADS)

Martin, Christopher Robert

The objective of this research project was to fabricate a functional ferroelectric microcantilever from patterned lead zirconate titanate (PZT) thin films. Cantilevers fabricated from ferroelectric materials have tremendous potential in sensing applications, particularly due to the increased sensitivity that miniaturized devices offer. This thesis highlights and explores a number of the processing issues that hindered the production of a working prototype. PZT is patterned using soft lithography-inspired techniques from a PZT chemical precursor solution derived by the chelation synthesis route. As the ability to pattern ceramic materials derived from sol-gels on the micrometer scale is a relatively new technology, this thesis aims to expand the scientific understanding of new issues that arise when working with these patterned films. For example, the use of Micromolding in Capillaries (MIMIC) to pattern the PZT thin films results in the evolution of topographical distortions from the shape of the original mold during the shrinkage of patterned thin film during drying and sintering. The factors that contribute to this effect have been explained and a new processing technique called MicroChannel Molding (muCM) was developed. This new process combines the advantages of soft lithography with traditional silicon microfabrication techniques to ensure compatibility with current industrial practices. This work lays the foundation for the future production of working ferroelectric microcantilevers. The proposed microfabrication process is described along with descriptions of each processing difficulty that was encountered. Modifications to the process are proposed along with the descriptions of alternative processing techniques that were attempted for the benefit of future researchers. This dissertation concludes with the electronic characterization of micropattemed PZT thin films. To our knowledge, the ferroelectric properties of patterned PZT thin films have never been directly characterized before. The properties are measured with a commercial ferroelectric test system connected through a conductive Atomic Force Microscope tip. The films patterned by MIMIC and muCM are compared to large-area spin cast films to identify the role that the processing method has on the resulting properties.

The Future of Pharmaceutical Manufacturing Sciences

PubMed Central

2015-01-01

The entire pharmaceutical sector is in an urgent need of both innovative technological solutions and fundamental scientific work, enabling the production of highly engineered drug products. Commercial‐scale manufacturing of complex drug delivery systems (DDSs) using the existing technologies is challenging. This review covers important elements of manufacturing sciences, beginning with risk management strategies and design of experiments (DoE) techniques. Experimental techniques should, where possible, be supported by computational approaches. With that regard, state‐of‐art mechanistic process modeling techniques are described in detail. Implementation of materials science tools paves the way to molecular‐based processing of future DDSs. A snapshot of some of the existing tools is presented. Additionally, general engineering principles are discussed covering process measurement and process control solutions. Last part of the review addresses future manufacturing solutions, covering continuous processing and, specifically, hot‐melt processing and printing‐based technologies. Finally, challenges related to implementing these technologies as a part of future health care systems are discussed. © 2015 The Authors. Journal of Pharmaceutical Sciences published by Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:3612–3638, 2015 PMID:26280993

The Future of Pharmaceutical Manufacturing Sciences.

PubMed

Rantanen, Jukka; Khinast, Johannes

2015-11-01

The entire pharmaceutical sector is in an urgent need of both innovative technological solutions and fundamental scientific work, enabling the production of highly engineered drug products. Commercial-scale manufacturing of complex drug delivery systems (DDSs) using the existing technologies is challenging. This review covers important elements of manufacturing sciences, beginning with risk management strategies and design of experiments (DoE) techniques. Experimental techniques should, where possible, be supported by computational approaches. With that regard, state-of-art mechanistic process modeling techniques are described in detail. Implementation of materials science tools paves the way to molecular-based processing of future DDSs. A snapshot of some of the existing tools is presented. Additionally, general engineering principles are discussed covering process measurement and process control solutions. Last part of the review addresses future manufacturing solutions, covering continuous processing and, specifically, hot-melt processing and printing-based technologies. Finally, challenges related to implementing these technologies as a part of future health care systems are discussed. © 2015 The Authors. Journal of Pharmaceutical Sciences published by Wiley Periodicals, Inc. and the American Pharmacists Association.

Transparent Carbon Nanotube layers as cathodes in OLEDs

NASA Astrophysics Data System (ADS)

Papadimitratos, Alexios; Nasibulin, Albert; Kauppinen, Esko; Zakhidov, Anvar; Solarno Inc Collaboration; Aalto University Collaboration; UT Dallas Collaboration

2011-03-01

Organic Light Emitting diodes (OLEDs) have attracted high interest in recent years due to their potential use in future lighting and display applications. Reported work on OLEDs traditionally utilizes low work function materials as cathodes that are expensive to fabricate because of the high vacuum processing. Transparent carbon nanotube (CNT) sheets have excellent mechanical and electrical properties. We have already shown earlier that multi-wall (MWCNT) as well as single CNT (SWCNT) sheets can be used as effective anodes in bright OLEDs [,]. The true advantage of using the CNT sheets lies in flexible devices and new architectures with CNT sheet as layers in tandem devices with parallel connection. In this work, we are investigating the possibility of using SWCNT as cathodes in OLEDs. SWCNT sheets have been reported to show lower work function compared to MWCNT. Our work attempts to demonstrate transparent OLED devices with CNT anodes and cathodes. In the process, OLEDs with CNT cathodes have been fabricated in normal and inverted configurations using inorganic oxides (MoO3,ZnO) as invertion layers.

Water treatment by new-generation graphene materials: hope for bright future.

PubMed

Ali, Imran; Alharbi, Omar M L; Tkachev, Alexey; Galunin, Evgeny; Burakov, Alexander; Grachev, Vladimir A

2018-03-01

Water is the most important and essential component of earth's ecosystem playing a vital role in the proper functioning of flora and fauna. But, our water resources are contaminating continuously. The whole world may be in great water scarcity after few decades. Graphene, a single-atom thick carbon nanosheet, and graphene nanomaterials have bright future in water treatment technologies due to their extraordinary properties. Only few papers describe the use of these materials in water treatment by adsorption, filtration, and photodegradation methods. This article presents a critical evaluation of the contribution of graphene nanomaterials in water treatment. Attempts have been made to discuss the future perspectives of these materials in water treatment. Besides, the efforts are made to discuss the nanotoxicity and hazards of graphene-based materials. The suggestions are given to explore the full potential of these materials along with precautions of nanotoxicity and its hazards. It was concluded that the future of graphene-based materials is quite bright.

Current Status of Efforts on Standardizing Magnetic Resonance Imaging of Juvenile Idiopathic Arthritis: Report from the OMERACT MRI in JIA Working Group and Health-e-Child.

PubMed

Nusman, Charlotte M; Ording Muller, Lil-Sofie; Hemke, Robert; Doria, Andrea S; Avenarius, Derk; Tzaribachev, Nikolay; Malattia, Clara; van Rossum, Marion A J; Maas, Mario; Rosendahl, Karen

2016-01-01

To report on the progress of an ongoing research collaboration on magnetic resonance imaging (MRI) in juvenile idiopathic arthritis (JIA) and describe the proceedings of a meeting, held prior to Outcome Measures in Rheumatology (OMERACT) 12, bringing together the OMERACT MRI in JIA working group and the Health-e-Child radiology group. The goal of the meeting was to establish agreement on scoring definitions, locations, and scales for the assessment of MRI of patients with JIA for both large and small joints. The collaborative work process included premeeting surveys, presentations, group discussions, consensus on scoring methods, pilot scoring, conjoint review, and discussion of a future research agenda. The meeting resulted in preliminary statements on the MR imaging protocol of the JIA knee and wrist and determination of the starting point for development of MRI scoring systems based on previous studies. It was also considered important to be descriptive rather than explanatory in the assessment of MRI in JIA (e.g., "thickening" instead of "hypertrophy"). Further, the group agreed that well-designed calibration sessions were warranted before any future scoring exercises were conducted. The combined efforts of the OMERACT MRI in JIA working group and Health-e-Child included the assessment of currently available material in the literature and determination of the basis from which to start the development of MRI scoring systems for both the knee and wrist. The future research agenda for the knee and wrist will include establishment of MRI scoring systems, an atlas of MR imaging in healthy children, and MRI protocol requisites.

Comprehensive work plan for Building 3001 storage canal at the Oak Ridge National Laboratory, Oak Ridge, Tennessee

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

NONE

1997-01-01

This Comprehensive Work Plan describes the method of accomplishment to replace the shielding protection of the water in the canal with a controlled low strength material (CLSM) 4. The canal was used during the operation of the Oak Ridge Graphite Reactor in the 1940s and 1950s to transport spent fuel slugs and irradiated test materials from the reactor, under water to the hot cell in Building 3019 for further processing, packaging, and handling. After the reactor was shut down, the canal was used until 1990 to store some irradiated materials until they could be transferred to a Solid Waste Storagemore » Area. This task has the following objectives and components: (1) minimize potential future risk to human health and the environment; (2) reduce surveillance and maintenance cost of the canal; (3) perform site preparation activities; (4) replace the water in the canal with a solid CLSM; (5) pump the water to the Process Waste Treatment System (PWTS) for further processing at the same rate that the CLSM is pumped under the water; (6) remove the water using a process that will protect the workers and the public in the visitors area from contamination while the CLSM is being pumped underneath the water; (7) painting a protective coating material over the CLSM after the CLSM has cured.« less

Spacelab

NASA Image and Video Library

1992-01-01

The IML-1 mission was the first in a series of Shuttle flights dedicated to fundamental materials and life sciences research with the international partners. The participating space agencies included: NASA, the 14-nation European Space Agency (ESA), the Canadian Space Agency (CSA), the French National Center of Space Studies (CNES), the German Space Agency and the German Aerospace Research Establishment (DAR/DLR), and the National Space Development Agency of Japan (NASDA). Dedicated to the study of life and materials sciences in microgravity, the IML missions explored how life forms adapt to weightlessness and investigated how materials behave when processed in space. Both life and materials sciences benefited from the extended periods of microgravity available inside the Spacelab science module in the cargo bay of the Space Shuttle Orbiter. In this photograph, Commander Ronald J. Grabe works with the Mental Workload and Performance Evaluation Experiment (MWPE) in the IML-1 module. This experiment was designed as a result of difficulty experienced by crewmembers working at a computer station on a previous Space Shuttle mission. The problem was due to the workstation's design being based on Earthbound conditions with the operator in a typical one-G standing position. Information gained from this experiment was used to design workstations for future Spacelab missions and the International Space Station. Managed by the Marshall Space Flight Center, IML-1 was launched on January 22, 1992 aboard the Space Shuttle Orbiter Discovery (STS-42 mission).

Measurements of Mode I Interlaminar Properties of Carbon Fiber Reinforced Polymers Using Digital Image Correlation

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

Merzkirch, Matthias; Ahure Powell, Louise; Foecke, Tim

Numerical models based on cohesive zones are usually used to model and simulate the mechanical behavior of laminated carbon fiber reinforced polymers (CFRP) in automotive and aerospace applications and require different interlaminar properties. This work focuses on determining the interlaminar fracture toughness (G IC) under Mode I loading of a double cantilever beam (DCB) specimen of unidirectional CFRP, serving as prototypical material. The novelty of this investigation is the improvement of the testing methodology by introducing digital image correlation (DIC) as an extensometer and this tool allows for crack growth measurement, phenomenological visualization and quantification of various material responses tomore » Mode I loading. Multiple methodologies from different international standards and other common techniques are compared for the determination of the evolution of G IC as crack resistance curves (R-curves). The primarily metrological sources of uncertainty, in contrast to material specific related uncertainties, are discussed through a simple sensitivity analysis. Additionally, the current work offers a detailed insight into the constraints and assumptions to allow exploration of different methods for the determination of material properties using the DIC measured data. The main aim is an improvement of the measurement technique and an increase in the reliability of measured data during static testing, in advance of future rate dependent testing for crashworthiness simulations.« less

Nonlinear machine learning in soft materials engineering and design

NASA Astrophysics Data System (ADS)

Ferguson, Andrew

The inherently many-body nature of molecular folding and colloidal self-assembly makes it challenging to identify the underlying collective mechanisms and pathways governing system behavior, and has hindered rational design of soft materials with desired structure and function. Fundamentally, there exists a predictive gulf between the architecture and chemistry of individual molecules or colloids and the collective many-body thermodynamics and kinetics. Integrating machine learning techniques with statistical thermodynamics provides a means to bridge this divide and identify emergent folding pathways and self-assembly mechanisms from computer simulations or experimental particle tracking data. We will survey a few of our applications of this framework that illustrate the value of nonlinear machine learning in understanding and engineering soft materials: the non-equilibrium self-assembly of Janus colloids into pinwheels, clusters, and archipelagos; engineering reconfigurable ''digital colloids'' as a novel high-density information storage substrate; probing hierarchically self-assembling onjugated asphaltenes in crude oil; and determining macromolecular folding funnels from measurements of single experimental observables. We close with an outlook on the future of machine learning in soft materials engineering, and share some personal perspectives on working at this disciplinary intersection. We acknowledge support for this work from a National Science Foundation CAREER Award (Grant No. DMR-1350008) and the Donors of the American Chemical Society Petroleum Research Fund (ACS PRF #54240-DNI6).

Measurements of Mode I Interlaminar Properties of Carbon Fiber Reinforced Polymers Using Digital Image Correlation

DOE PAGES

Merzkirch, Matthias; Ahure Powell, Louise; Foecke, Tim

2017-07-01

Numerical models based on cohesive zones are usually used to model and simulate the mechanical behavior of laminated carbon fiber reinforced polymers (CFRP) in automotive and aerospace applications and require different interlaminar properties. This work focuses on determining the interlaminar fracture toughness (G IC) under Mode I loading of a double cantilever beam (DCB) specimen of unidirectional CFRP, serving as prototypical material. The novelty of this investigation is the improvement of the testing methodology by introducing digital image correlation (DIC) as an extensometer and this tool allows for crack growth measurement, phenomenological visualization and quantification of various material responses tomore » Mode I loading. Multiple methodologies from different international standards and other common techniques are compared for the determination of the evolution of G IC as crack resistance curves (R-curves). The primarily metrological sources of uncertainty, in contrast to material specific related uncertainties, are discussed through a simple sensitivity analysis. Additionally, the current work offers a detailed insight into the constraints and assumptions to allow exploration of different methods for the determination of material properties using the DIC measured data. The main aim is an improvement of the measurement technique and an increase in the reliability of measured data during static testing, in advance of future rate dependent testing for crashworthiness simulations.« less

Dissolution of Olivine, Siderite, and Basalt at 80 Deg C in 0.1 M H2SO4 in a Flow Through Process: Insights into Acidic Weathering on Mars

NASA Technical Reports Server (NTRS)

Golden, D. C.; Ming, D. W.; Hausrath, E. M.; Morris, R. V.; Niles, P. B.; Achilles, C. N.; Ross, D. K.; Cooper, B. L.; Gonzalex, C. P.; Mertzman, S. A.

2012-01-01

The occurrence of jarosite, other sulfates (e.g., Mg-and Ca-sulfates), and hematite along with silicic-lastic materials in outcrops of sedimentary materials at Meridiani Planum (MP) and detection of silica rich deposits in Gusev crater, Mars, are strong indicators of local acidic aqueous processes [1,2,3,4,5]. The formation of sediments at Meridiani Planum may have involved the evaporation of fluids derived from acid weathering of Martian basalts and subsequent diagenesis [6,7]. Also, our previous work on acid weathering of basaltic materials in a closed hydro-thermal system was focused on the mineralogy of the acid weathering products including the formation of jarosite and gray hematite spherules [8,9,10]. The object of this re-search is to extend our earlier qualitative work on acidic weathering of rocks to determine acidic dissolution rates of Mars analog basaltic materials at 80 C using a flow-thru reactor. We also characterized residual phases, including poorly crystalline or amorphous phases and precipitates, that remained after the treatments of olivine, siderite, and basalt which represent likely MP source rocks. This study is a stepping stone for a future simulation of the formation of MP rocks under a range of T and P.

Comparative Analysis of Supply Risk-Mitigation Strategies for Critical Byproduct Minerals: A Case Study of Tellurium.

PubMed

Bustamante, Michele L; Gaustad, Gabrielle; Alonso, Elisa

2018-01-02

Materials criticality assessment is a screening framework increasingly applied to identify materials of importance that face scarcity risks. Although these assessments highlight materials for the implicit purpose of informing future action, the aggregated nature of their findings make them difficult to use for guidance in developing nuanced mitigation strategy and policy response. As a first step in the selection of mitigation strategies, the present work proposes a modeling framework and accompanying set of metrics to directly compare strategies by measuring effectiveness of risk reduction as a function of the features of projected supply demand balance over time. The work focuses on byproduct materials, whose criticality is particularly important to understand because their supplies are inherently less responsive to market balancing forces, i.e., price feedbacks. Tellurium, a byproduct of copper refining, which is critical to solar photovoltaics, is chosen as a case study, and three commonly discussed byproduct-relevant strategies are selected: dematerialization of end-use product, byproduct yield improvement, and end-of-life recycling rate improvement. Results suggest that dematerialization will be nearly twice as effective at reducing supply risk as the next best option, yield improvement. Finally, due to its infrequent use at present and its dependence upon long product lifespans, recycling end-of-life products is expected to be the least effective option despite potentially offering other benefits (e.g., cost savings and environmental impact reduction).

Towards Rational Design of Functional Fluoride and Oxyfluoride Materials from First Principles

NASA Astrophysics Data System (ADS)

Charles, Nenian

Complex transition metal compounds (TMCs) research has produced functional materials with a range of properties, including ferroelectricity, colossal magnetoresistance, nonlinear optical activity and high-temperature superconductivity. Conventional routes to tune properties in transition metal oxides, for example, have relied primarily on cation chemical substitution and interfacial effects in thin film heterostructures. In heteroanionic TMCs, exhibiting two chemically distinct anions coordinating the same or different cations, engineering of the anion sub-lattice for property control is a promising alternative approach. The presence of multiple anions provides additional design variables, such as anion order, that are absent in homoanionic counterparts. The more complex structural and chemical phase space of heteroanionic materials provides a unique opportunity to realize enhanced or unanticipated electronic, optical, and magnetic responses. Although there is growing interest in heteroanionic materials, and synthetic and characterization advances are occurring for these materials, the crystal-chemistry principles for realizing structural and property control are only slowing emerging. This dissertation employs anion engineering to investigate phenomena in transition metal fluorides and oxyfluorides compounds using first principles density functional theory calculations. Oxyfluorides are particularly intriguing owing their tendency to stabilize highly ordered anion sublattices as well as the potential to combine the advantageous properties of transition metal oxides and fluorides. This work 1) addresses the challenges of studying fluorides and oxyfluorides using first principles calculations; 2) evaluates the feasibility of using external stimuli, such as epitaxial strain and hydrostatic pressure, to control properties of fluorides and oxyfluorides; and 3) formulates a computational workflow based on multiple levels of theory and computation to elucidate structure-property relationships and anion-order descriptors. The insights gained in this work advance the understanding of oxide-fluoride anion engineered materials and we anticipate that it will motivate novel experimental efforts and materials by design in the future.

Magnetic spectroscopy and microscopy of functional materials

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

Jenkins, Catherine Ann

2011-05-01

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

Modern Advances in Genetic Testing: Ethical Challenges and Training Implications for Current and Future Psychologists

PubMed Central

Richmond-Rakerd, Leah S.

2014-01-01

The ethical implications for psychological practice of genetic testing are largely unexplored. Predictive testing can have a significant impact on health and well-being, and increasing numbers of individuals with knowledge of their risk for various disorders are likely to present for psychotherapy. In addition, more people will struggle with the decision of whether to obtain information regarding their genetic material. Psychologists will need to have the appropriate knowledge and clinical skills to effectively counsel this population. This article highlights the relevant ethical issues surrounding psychological treatment of individuals pursuing or considering undergoing genetic testing. These issues are extended to psychologists working in research, education, and policy domains. Recommendations for graduate training programs to facilitate current and future practitioner competence are also discussed. PMID:24707160

The aluminum smelting process and innovative alternative technologies.

PubMed

Kvande, Halvor; Drabløs, Per Arne

2014-05-01

The industrial aluminum production process is addressed. The purpose is to give a short but comprehensive description of the electrolysis cell technology, the raw materials used, and the health and safety relevance of the process. This article is based on a study of the extensive chemical and medical literature on primary aluminum production. At present, there are two main technological challenges for the process--to reduce energy consumption and to mitigate greenhouse gas emissions. A future step may be carbon dioxide gas capture and sequestration related to the electric power generation from fossil sources. Workers' health and safety have now become an integrated part of the aluminum business. Work-related injuries and illnesses are preventable, and the ultimate goal to eliminate accidents with lost-time injuries may hopefully be approached in the future.

Length and Dimensional Measurements at NIST

PubMed Central

Swyt, Dennis A.

2001-01-01

This paper discusses the past, present, and future of length and dimensional measurements at NIST. It covers the evolution of the SI unit of length through its three definitions and the evolution of NBS-NIST dimensional measurement from early linescales and gage blocks to a future of atom-based dimensional standards. Current capabilities include dimensional measurements over a range of fourteen orders of magnitude. Uncertainties of measurements on different types of material artifacts range down to 7×10−8 m at 1 m and 8 picometers (pm) at 300 pm. Current work deals with a broad range of areas of dimensional metrology. These include: large-scale coordinate systems; complex form; microform; surface finish; two-dimensional grids; optical, scanning-electron, atomic-force, and scanning-tunneling microscopies; atomic-scale displacement; and atom-based artifacts. PMID:27500015

The Effect of Maternal Employment on the Elementary and Junior High School Students’ Mental Health in Maku

PubMed Central

Aghdam, Fatemeh Bakhtari; Ahmadzadeh, Sakineh; Hassanalizadeh, Zahra; Ebrahimi, Fatemeh; Sabzmakan, Leila; Javadivala, Zeinab

2015-01-01

Background and Objective: Most experts view the childhood period as a foundation for shaping the individuals’ fundamental future characteristics and behaviors. They believe that parents’ personality and behavior quality exert a greater effect on the development of a child’s personality than other factors. Given the mothers’ role in children’s mental health and considering the fact that children are a nation’s future makers, the present study was designed to investigate the impact of maternal employment on students’ mental health in Maku. Materials and Methods: The present study is descriptive and cross-sectional, and the population of the study encompasses all students in the fifth, sixth, and seventh grades (n=583) who are studying in 2013-2014 academic year in Maku. General Heath Questionnaire was employed for gathering data, and the SPSS software was used for analyzing the data. Findings: The results of the study indicated that there was a significant difference between the mental health problems, somatic problems, social functioning, anxiety, and depression of the students with employed and non-employed mothers. In other words, the students with non-working mothers experienced greater mental disorders than those with working mothers. Conclusion: According to the findings of this study, it can be concluded that children with working mothers showed a better mental health than non-working mothers’ children. PMID:25716412

On the suitability of Synbone® as a tissue simulant

NASA Astrophysics Data System (ADS)

Appleby-Thomas, Gareth; Fitzmaurice, Brianna; Hameed, Amer; Wood, David; Gibson, Mike; Painter, Jonathan

2015-06-01

The applicability of various materials as human tissue analogues has been a topic of increasing interest in recent years. It allows for more cost-effective experiments to be carried out, but also avoids ethical issues that would arise from using real human tissue. Synbone® , a porous polyurethane material, is commonly used in ballistic experiments as a bone simulant, but until now has not been characterised in terms of its dynamic behaviour. Here, the Hugoniot equation-of-state (EOS) for Synbone® has been derived via a series of plate-impact experiments; highlighting the importance of the underlying material structure in terms of material collapse under high strain-rates. A series of ballistic tests were also undertaken to provide further insight into the ballistic response of Synbone® and its potential role as a tissue simulant. This work - following on from previous in-house studies of other tissue analogues - has provided useful data for future simulation of this material. In addition, comparison to dynamic data for other tissue and simulant materials has highlighted the importance of considering tissue as non-monolithic; each layer of tissue should ideally be represented by its own simulant in ballistic experiments.

Physics and chemistry of complex oxide etching and redeposition control

NASA Astrophysics Data System (ADS)

Margot, Joëlle

2012-10-01

Since its introduction in the 1970s, plasma etching has become the universal method for fine-line pattern transfer onto thin films and is anticipated to remain so in foreseeable future. Despite many success stories, plasma etching processes fail to meet the needs for several of the newest materials involved in advanced devices for photonic, electronic and RF applications like ferroelectrics, electro-optic materials, high-k dielectrics, giant magnetoresistance materials and unconventional conductors. In this context, the work achieved over the last decade on the etching of multicomponent oxides thin films such as barium strontium titanate (BST), strontium titanate (STO) and niobate of calcium and barium (CBN) will be reviewed. These materials present a low reactivity with usual etching gases such as fluorinated and chlorinated gases, their etching is mainly governed by ion sputtering and reactive gases sometimes interact with surface materials to form compounds that inhibit etching. The etching of platinum will also be presented as an example of unconventional conductor materials for which severe redeposition limits the achievable etching quality. Finally, it will be shown how simulation can help to understand the etching mechanisms and to define avenues for higher quality patterning.

Tensile Strength and Microstructure of Al2O3-ZrO2 Hypo-Eutectic Fibers Studied

NASA Technical Reports Server (NTRS)

Farmer, Serene C.; Sayir, Ali

2001-01-01

Oxide eutectics offer high-temperature strength retention and creep resistance in oxidizing environments. Al2O3-ZrO2 eutectic strengths have been studied since the 1970's. Directionally solidified oxide eutectics exhibit improved resistance to slow crack growth and excellent strength retention at high temperatures up to 1400 C. Materials studied typically contain Y2O3 to metastably retain the high-temperature cubic and tetragonal polymorphs at room temperature. Al2O3-ZrO2 is of fundamental interest for creep studies because it combines a creep-resistant material, Al2O3, with a very low creep resistance material, ZrO2. Results on mechanical properties and microstructures of these materials will be used to define compositions for creep testing in future work. Substantial variations from the eutectic alumina to zirconia ratio can be tolerated without a loss in room-temperature strength. The effect of increasing Y2O3 addition on the room-temperature tensile strength of an Al2O3-ZrO2 material containing excess Al2O3 was examined at the NASA Glenn Research Center, where the materials were grown using Glenn's world-class laser growth facilities.

Code qualification of structural materials for AFCI advanced recycling reactors.

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

Natesan, K.; Li, M.; Majumdar, S.

2012-05-31

This report summarizes the further findings from the assessments of current status and future needs in code qualification and licensing of reference structural materials and new advanced alloys for advanced recycling reactors (ARRs) in support of Advanced Fuel Cycle Initiative (AFCI). The work is a combined effort between Argonne National Laboratory (ANL) and Oak Ridge National Laboratory (ORNL) with ANL as the technical lead, as part of Advanced Structural Materials Program for AFCI Reactor Campaign. The report is the second deliverable in FY08 (M505011401) under the work package 'Advanced Materials Code Qualification'. The overall objective of the Advanced Materials Codemore » Qualification project is to evaluate key requirements for the ASME Code qualification and the Nuclear Regulatory Commission (NRC) approval of structural materials in support of the design and licensing of the ARR. Advanced materials are a critical element in the development of sodium reactor technologies. Enhanced materials performance not only improves safety margins and provides design flexibility, but also is essential for the economics of future advanced sodium reactors. Code qualification and licensing of advanced materials are prominent needs for developing and implementing advanced sodium reactor technologies. Nuclear structural component design in the U.S. must comply with the ASME Boiler and Pressure Vessel Code Section III (Rules for Construction of Nuclear Facility Components) and the NRC grants the operational license. As the ARR will operate at higher temperatures than the current light water reactors (LWRs), the design of elevated-temperature components must comply with ASME Subsection NH (Class 1 Components in Elevated Temperature Service). However, the NRC has not approved the use of Subsection NH for reactor components, and this puts additional burdens on materials qualification of the ARR. In the past licensing review for the Clinch River Breeder Reactor Project (CRBRP) and the Power Reactor Innovative Small Module (PRISM), the NRC/Advisory Committee on Reactor Safeguards (ACRS) raised numerous safety-related issues regarding elevated-temperature structural integrity criteria. Most of these issues remained unresolved today. These critical licensing reviews provide a basis for the evaluation of underlying technical issues for future advanced sodium-cooled reactors. Major materials performance issues and high temperature design methodology issues pertinent to the ARR are addressed in the report. The report is organized as follows: the ARR reference design concepts proposed by the Argonne National Laboratory and four industrial consortia were reviewed first, followed by a summary of the major code qualification and licensing issues for the ARR structural materials. The available database is presented for the ASME Code-qualified structural alloys (e.g. 304, 316 stainless steels, 2.25Cr-1Mo, and mod.9Cr-1Mo), including physical properties, tensile properties, impact properties and fracture toughness, creep, fatigue, creep-fatigue interaction, microstructural stability during long-term thermal aging, material degradation in sodium environments and effects of neutron irradiation for both base metals and weld metals. An assessment of modified versions of Type 316 SS, i.e. Type 316LN and its Japanese version, 316FR, was conducted to provide a perspective for codification of 316LN or 316FR in Subsection NH. Current status and data availability of four new advanced alloys, i.e. NF616, NF616+TMT, NF709, and HT-UPS, are also addressed to identify the R&D needs for their code qualification for ARR applications. For both conventional and new alloys, issues related to high temperature design methodology are described to address the needs for improvements for the ARR design and licensing. Assessments have shown that there are significant data gaps for the full qualification and licensing of the ARR structural materials. Development and evaluation of structural materials require a variety of experimental facilities that have been seriously degraded in the past. The availability and additional needs for the key experimental facilities are summarized at the end of the report. Detailed information covered in each Chapter is given.« less

Evaluation of Commercial Off-the-Shelf Sorbents and Catalysts for Control of Ammonia and Carbon Monoxide

NASA Technical Reports Server (NTRS)

Luna, Bernadette; Somi, George; Winchester, J. Parker; Grose, Jeffrey; Mulloth, Lila; Perry, Jay L.

2010-01-01

Designers of future space vehicles envision simplifying the Atmosphere Revitalization (AR) system by combining the functions of trace contaminant (TC) control and carbon dioxide removal into one swing-bed system. Flow rates and bed sizes of the TC and CO2 systems have historically been very different. There is uncertainty about the ability of trace contaminant sorbents to adsorb adequately in high-flow or short bed length configurations, and to desorb adequately during short vacuum exposures. There is also concern about ambient ammonia levels in the absence of a condensing heat exchanger. In addition, new materials and formulations have become commercially available, formulations never evaluated by NASA for purposes of trace contaminant control. The optimal air revitalization system for future missions may incorporate a swing-bed system for carbon dioxide (CO2) and partial trace contaminant control, with a reduced-size, low-power, targeted trace contaminant system supplying the remaining contaminant removal capability. This paper describes the results of a comparative experimental investigation into materials for trace contaminant control that might be part of such a system. Ammonia sorbents and low temperature carbon monoxide (CO) oxidation catalysts are the foci. The data will be useful to designers of AR systems for future flexible path missions. This is a continuation of work presented in a prior year, with extended test results.

Evaluation of Commercial Off-the-Shelf Sorbents and Catalysts for Control of Ammonia and Carbon Monoxide

NASA Technical Reports Server (NTRS)

Luna, Bernadette; Somi, George; Winchester, J. Parker; Grose, Jeffrey; Mulloth, Lila; Perry, Jay L.

2013-01-01

Designers of future space vehicles envision simplifying the Atmosphere Revitalization (AR) system by combining the functions of trace contaminant (TC) control and carbon dioxide removal into one swing-bed system. Flow rates and bed sizes of the TC and CO2 systems have historically been very different. There is uncertainty about the ability of trace contaminant sorbents to adsorb adequately in high-flow or short bed length configurations, and to desorb adequately during short vacuum exposures. There is also concern about ambient ammonia levels in the absence of a condensing heat exchanger. In addition, new materials and formulations have become commercially available, formulations never evaluated by NASA for purposes of trace contaminant control. The optimal air revitalization system for future missions may incorporate a swing-bed system for carbon dioxide (CO2) and partial trace contaminant control, with a reduced-size, low-power, targeted trace contaminant system supplying the remaining contaminant removal capability. This paper describes the results of a comparative experimental investigation into materials for trace contaminant control that might be part of such a system. Ammonia sorbents and low temperature carbon monoxide (CO) oxidation catalysts are the foci. The data will be useful to designers of AR systems for future flexible path missions. This is a continuation of work presented in a prior year, with extended test results.

Health professionals' use of documents obtained through the Regional Medical Library Network.

PubMed

Lovas, I; Graham, E; Flack, V

1991-01-01

The Pacific Southwest Regional Medical Library Service (PSRMLS) studied how health professionals use documents obtained through the regional medical library (RML) network and how various factors, such as delivery time, affected that use. A random sample of libraries in Region 7 of the RML network was selected to survey health professionals who had received documents through the interlibrary loan (ILL) network. The survey provided data about the purposes for which health professionals requested documents, how the immediacy of need for the items affected their usefulness, what effect the obtained information had on the health professionals' work, and whether the illustrations represented an important part of the information content of the items. Survey results provided a positive assessment of the ILL network. Results also verified the basic value of the materials provided to health professionals through ILL and identified some areas for consideration in future network development. Users of the documents indicated that the network works efficiently and effectively to provide timely and useful information needed by health professionals. Technological developments in electronic information transmission and imaging will further enhance network operation in the future.

NuMI Flux Predictions for NOvA and MINERvA

NASA Astrophysics Data System (ADS)

Aliaga Soplin, Leonidas; Nova Collaboration; Minerva Collaboration

2017-01-01

The determination of the neutrino flux in any conventional neutrino beam presents a challenge for the current and future short and long baseline neutrino experiments. The uncertainties associated with the production and attenuation of the hadrons in the beamline materials along with those associated with the beam optics have a big effect in the knowledge of the flux. For experiments like MINERvA and NOvA, understanding the flux is crucial since it enters directly into every neutrino-nucleus cross-section measurement. The majority of this work involves predicting the neutrino flux using dedicated hadron production measurements from hadron-nucleus collisions. The predictions at the MINERvA and NOvA near detectors are presented as well as the results of incorporating in-situ MINERvA data that can provide additional constraints. These results have been fully implemented in MINERvA and they are currently use for its cross-section analysis. The implementation for NoVA is underway. The procedure and conclusions of this work will have a big impact on future hadron production experiments and on determining the flux for the upcoming DUNE experiment.

Industry technology assessment of graphite-polymide composite materials. [conferences

NASA Technical Reports Server (NTRS)

1975-01-01

An assessment of the current state of the art and the future prospects for graphite polyimide composite material technology is presented. Presentations and discussions given at a minisymposium of major issues on the present and future use, availability, processing, manufacturing, and testing of graphite polyimide composite materials are summarized.

Investigation of Friction Stir Welding and Laser Engineered Net Shaping of Metal Matrix Composite Materials

NASA Technical Reports Server (NTRS)

Diwan, Ravinder M.

2002-01-01

The improvement in weld quality by the friction stir welding (FSW) process invented by TWI of Cambridge, England, patented in 1991, has prompted investigation of this process for advanced structural materials including Al metal matrix composite (Al-MMC) materials. Such materials can have high specific stiffness and other potential beneficial properties for the extreme environments in space. Developments of discontinuous reinforced Al-MMCs have found potential space applications and the future for such applications is quite promising. The space industry has recognized advantages of the FSW process over conventional welding processes such as the absence of a melt zone, reduced distortion, elimination of the need for shielding gases, and ease of automation. The process has been well proven for aluminum alloys, and work is being carried out for ferrous materials, magnesium alloys and copper alloys. Development work in the FSW welding process for joining of Al-MMCs is relatively recent and some of this and related work can be found in referenced research publications. NASA engineers have undertaken to spear head this research development work for FSW process investigation of Al-MMCs. Some of the reported related work has pointed out the difficulty in fusion welding of particulate reinforced MMCs where liquid Al will react with SiC to precipitate aluminum carbide (Al4C3). Advantages of no such reaction and no need for joint preparation for the FSW process is anticipated in the welding of Al-MMCs. The FSW process has been best described as a combination of extrusion and forging of metals. This is carried out as the pin tool rotates and is slowly plunged into the bond line of the joint as the pin tool's shoulder is in intimate contact with the work piece. The material is friction-stirred into a quality weld. Al-MMCs, 4 in. x 12 in. plates of 0.25 in. (6.35mm) thickness, procured from MMCC, Inc. were butt welded using FSW process at Marshall Space Flight Center (MSFC) using prior set of operating conditions. Weld quality was evaluated using radiography and standard metallography techniques. Another aspect of the MMCs centered around the use of the laser engineered net shaping (LENS) processing of selected Narloy-Z composites. Such an approach has been earlier studied for fabrication of stainless steels. In the present study, attempts were made to fabricate straight cylindrical specimens using LENS process of Narloy-Z and Narloy-Z with 20 vol. % Al2O3 MMCs using the direct metal deposition Optomec LENS-750 system.

Current Space Station Experiments Investigating Component Level Electronics Repair

NASA Technical Reports Server (NTRS)

Easton, John W.; Struk, Peter M.

2010-01-01

The Soldering in a Reduced Gravity Experiment (SoRGE) and Component Repair Experiment (CRE)-1 are tests performed on the International Space Station to determine the techniques, tools, and training necessary to allow future crews to perform manual electronics repairs at the component level. SoRGE provides information on the formation and internal structure of through-hole solder joints, illustrating the challenges and implications of soldering in reduced gravity. SoRGE showed a significant increase in internal void defects for joints formed in low gravity compared to normal gravity. Methods for mitigating these void defects were evaluated using a modified soldering process. CRE-1 demonstrated the removal, cleaning, and replacement of electronics components by manual means on functional circuit boards. The majority of components successful passed a post-repair functional test demonstrating the feasibility of component-level repair within the confines of a spacecraft. Together, these tasks provide information to recommend material and tool improvements, training improvements, and future work to help enable electronics repairs in future space missions.

Water-Assisted Production of Thermoplastic Nanocomposites: A Review.

PubMed

Karger-Kocsis, József; Kmetty, Ákos; Lendvai, László; Drakopoulos, Stavros X; Bárány, Tamás

2014-12-29

Water-assisted, or more generally liquid-mediated, melt compounding of nanocomposites is basically a combination of solution-assisted and traditional melt mixing methods. It is an emerging technique to overcome several disadvantages of the above two. Water or aqueous liquids with additives, do not work merely as temporary carrier materials of suitable nanofillers. During batchwise and continuous compounding, these liquids are fully or partly evaporated. In the latter case, the residual liquid is working as a plasticizer. This processing technique contributes to a better dispersion of the nanofillers and affects markedly the morphology and properties of the resulting nanocomposites. A survey is given below on the present praxis and possible future developments of water-assisted melt mixing techniques for the production of thermoplastic nanocomposites.

Object classification and outliers analysis in the forthcoming Gaia mission

NASA Astrophysics Data System (ADS)

Ordóñez-Blanco, D.; Arcay, B.; Dafonte, C.; Manteiga, M.; Ulla, A.

2010-12-01

Astrophysics is evolving towards the rational optimization of costly observational material by the intelligent exploitation of large astronomical databases from both terrestrial telescopes and spatial mission archives. However, there has been relatively little advance in the development of highly scalable data exploitation and analysis tools needed to generate the scientific returns from these large and expensively obtained datasets. Among the upcoming projects of astronomical instrumentation, Gaia is the next cornerstone ESA mission. The Gaia survey foresees the creation of a data archive and its future exploitation with automated or semi-automated analysis tools. This work reviews some of the work that is being developed by the Gaia Data Processing and Analysis Consortium for the object classification and analysis of outliers in the forthcoming mission.

Flexible Electronics Development Supported by NASA

NASA Technical Reports Server (NTRS)

Baumann, Eric

2014-01-01

The commercial electronics industry is leading development in most areas of electronics for NASA applications; however, working in partnership with industry and the academic community, results from NASA research could lead to better understanding and utilization of electronic materials by the flexible electronics industry. Innovative ideas explored by our partners in industry and the broader U.S. research community help NASA execute our missions and bring new American products and services to the global technology marketplace. [Mike Gazarik, associate administrator for Space Technology, NASA Headquarters, Washington DC] This presentation provides information on NASA needs in electronics looking towards the future, some of the work being supported by NASA in flexible electronics, and the capabilities of the Glenn Research Center supporting the development of flexible electronics.

Repairing the damage to Atlantis' External Tank

NASA Image and Video Library

2007-03-07

On an upper level of high bay 1 of the Vehicle Assembly Building, technicians secure protective material around Atlantis' external tank. The preparations are for future repair work of the hail damage that happened Feb. 27. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. Further evaluation of the tank is necessary to get an accurate accounting of foam damage and determine the type of repair required and the time needed for that work. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117.

View of working with SAME Hardware in the US Lab during Expedition 15

NASA Image and Video Library

2007-09-08

ISS015-E-27397 (8 Sept. 2007) --- NASA astronaut Clay Anderson, Expedition 15 flight engineer, pauses for a photo while working on the Smoke and Aerosol Measurement Experiment (SAME) hardware located in the Microgravity Science Glovebox (MSG) in the Destiny laboratory of the International Space Station. SAME will measure the smoke properties, or particle size distribution, of typical particles that are produced from different materials that can be found onboard station and other spacecrafts. SAME aims to test the performance of ionization smoke detectors and evaluate the performance of the photoelectric smoke detectors. The data will be used to develop a model that can predict smoke droplet growth that will be used to evaluate future smoke detection devices.

Water-Assisted Production of Thermoplastic Nanocomposites: A Review

PubMed Central

Karger-Kocsis, József; Kmetty, Ákos; Lendvai, László; Drakopoulos, Stavros X.; Bárány, Tamás

2014-01-01

Water-assisted, or more generally liquid-mediated, melt compounding of nanocomposites is basically a combination of solution-assisted and traditional melt mixing methods. It is an emerging technique to overcome several disadvantages of the above two. Water or aqueous liquids with additives, do not work merely as temporary carrier materials of suitable nanofillers. During batchwise and continuous compounding, these liquids are fully or partly evaporated. In the latter case, the residual liquid is working as a plasticizer. This processing technique contributes to a better dispersion of the nanofillers and affects markedly the morphology and properties of the resulting nanocomposites. A survey is given below on the present praxis and possible future developments of water-assisted melt mixing techniques for the production of thermoplastic nanocomposites. PMID:28787925

Present and future applications of NMR to medicine and materials science

NASA Astrophysics Data System (ADS)

Morris, Peter

1992-06-01

The phenomenon of nuclear magnetic resonance (NMR) was first observed in the immediate post second-world-war period by two American physicists, working independently: Bloch at Stanford and Purcell at Harvard. Their observations were reported in 1946 in the same volume of Physical Review and led to the joint award of the 1952 Nobel Prize for Physics. Once the details of the interaction had been worked out, and the chemical specificity had been appreciated, a period of instrumentational refinement followed before NMR took its place as arguably the most powerful analytical technique available to the organic chemist. The historical development of NMR and the basis of its analytical power are described in the companion article by Dr. J. Feeney.

Survey of UK dentists regarding the use of CAD/CAM technology.

PubMed

Tran, D; Nesbit, M; Petridis, H

2016-11-18

Statement of the problem Digital workflows (CAD/CAM) have been introduced in dentistry during recent years. No published information exists on dentists' use and reporting of this technology.Purpose The purpose of this survey was to identify the infiltration of CAD/CAM technology in UK dental practices and to investigate the relationship of various demographic factors to the answers regarding use or non-use of this technology.Materials and methods One thousand and thirty-one online surveys were sent to a sample of UK dentists composing of both users and non-users of CAD/CAM. It aimed to reveal information regarding type of usage, materials, perceived benefits, barriers to access, and disadvantages of CAD/CAM dentistry. Statistical analysis was undertaken to test the influence of various demographic variables such as country of work, dentist experience, level of training and type of work (NHS or private).Results The number of completed responses totalled 385. Most of the respondents did not use any part of a digital workflow, and the main barriers to CAD/CAM use were initial costs and a lack of perceived benefit over conventional methods. Dentists delivering mostly private work were most likely to have adopted CAD/CAM technology (P <0.001). Further training also correlated with a greater likelihood of CAD/CAM usage (P <0.001). Most users felt that the technology had led to a change in the use of dental materials, leading to increased use of, for example, zirconia and lithium disilicate. Most users were trained either by companies or self-trained, and a third felt that their training was insufficient. The majority of respondents (89%) felt that CAD/CAM had a big role to play in the future.Conclusion Most of the respondents did not use any part of a digital workflow. However, the majority of surveyed dentists were interested in incorporating CAD/CAM into their workflow, while most believed that it will have a big role in the future. There are still some concerns from dentists about the quality of chairside CAD/CAM restorations while the costs are still in the main hugely prohibitive (especially for NHS dentistry).

Electronic publishing in radiology: economics and the future.

PubMed

Chew, Felix S; Llewellyn, Kevin T; Olsen, Kathryn M

2004-11-01

Scholarly publishing is a large market involving thousands of peer-reviewed journals but a decreasing number of publishers. An economic model can be described in which authors give their work to publishers who then sell access to this work. Because each published article is a unique work with few if any substitutes, publishers have some degree of monopoly power and can price their products accordingly. The advent of desktop publishing using personal computers made it possible for individuals to publish material without publishers, an activity that gained momentum when the publishing medium shifted from paper to electronic, and from electronic publishing to the Internet. This activity destabilized the industry, and in the rush to gain market share by providing free content, unsustainable business models were created. Scholarly publishing is now dominated by a small number of multinational corporations that acquired many smaller publishing operations. As these companies have exercised their monopoly power, an open access movement has gained traction in which authors (or their institutions) initially pay for publication, but readers have free and open access to the published articles. This movement is in diametric opposition to the commercial publishing model, and it remains to be seen whether and how well the two can coexist in the future.

Abrasion Testing of Candidate Outer Layer Fabrics for Lunar EVA Space Suits

NASA Technical Reports Server (NTRS)

Mitchell, Kathryn

2009-01-01

During the Apollo program, the space suit outer layer fabrics were severely abraded after just a few Extravehicular Activities (EVAs). For example, the Apollo 12 commander reported abrasive wear on the boots, which penetrated the outer layer fabric into the thermal protection layers after less than eight hours of surface operations. Current plans for the Constellation Space Suit Element require the space suits to support hundreds of hours of EVA on the Lunar surface, creating a challenge for space suit designers to utilize materials advances made over the last forty years and improve upon the space suit fabrics used in the Apollo program. A test methodology has been developed by the NASA Johnson Space Center Crew and Thermal Systems Division for establishing comparative abrasion wear characteristics between various candidate space suit outer layer fabrics. The abrasion test method incorporates a large rotary drum tumbler with rocks and loose lunar simulant material to induce abrasion in fabric test cylinder elements, representative of what might occur during long term planetary surface EVAs. Preliminary materials screening activities were conducted to determine the degree of wear on representative space suit outer layer materials and the corresponding dust permeation encountered between subsequent sub-layers of thermal protective materials when exposed to a simulated worst case eight hour EVA. The test method was used to provide a preliminary evaluation of four candidate outer layer fabrics for future planetary surface space suit applications. This paper provides a review of previous abrasion studies on space suit fabrics, details the methodologies used for abrasion testing in this particular study, shares the results of the testing, and provides recommendations for future work.

Work ability score and future work ability as predictors of register-based disability pension and long-term sickness absence: A three-year follow-up study.

PubMed

Kinnunen, Ulla; Nätti, Jouko

2018-05-01

We investigated two single items of the Work Ability Index - work ability score, and future work ability - as predictors of register-based disability pension and long-term sickness absence over a three-year follow-up. Survey responses of 11,131 Finnish employees were linked to pension and long-term (more than 10 days) sickness absence register data by Statistics Finland. Work ability score was divided into poor (0-5), moderate (6-7) and good/excellent (8-10) and future work ability into poor (1-2) and good (3) work ability at baseline. Cox proportional hazard regressions were used in the analysis of disability pension, and a negative binomial model in the analysis of long-term sickness absence. The results were adjusted for several background, work- and health-related covariates. Compared with those with good/excellent work ability scores, the hazard ratios of disability pension after adjusting for all covariates were 9.84 (95% CI 6.68-14.49) for poor and 2.25 (CI 95% 1.51-3.35) for moderate work ability score. For future work ability, the hazard ratio was 8.19 (95% CI 4.71-14.23) among those with poor future work ability. The incidence rate ratios of accumulated long-term sickness absence days were 3.08 (95% CI 2.19-4.32) and 1.59 (95% CI 1.32-1.92) for poor and moderate work ability scores, and 1.51 (95% CI 0.97-2.36) for poor future work ability. The single items of work ability score and future work ability predicted register-based disability pension equally well, but work ability score was a better predictor of register-based long-term sickness absence days than future work ability in a three-year follow-up. Both items seem to be of use especially when examining the risk of poor work ability for disability but also for long sick leave.

Mass spectrometer-pyrolysis experiment for atmospheric and soil sample analysis on the surface of Mars

NASA Technical Reports Server (NTRS)

Mauersberger, Konrad; Mahaffy, Paul; Niemann, Hasso

1992-01-01

Results from the Viking mission will form the foundation for future in-depth investigations of atmosphere-surface interactions on Mars. The two Viking landers carried impressive instrumentation to obtain and analyze soil samples: the sites were observed by cameras, and the collector head was located on a long boom and allowed the collection of large samples at various depths. A selection of grain sizes was possible and a distribution system supplied a number of experiments with soil material. Despite stationary vehicles, a wide sampling field was reachable. The GCMS system, responsible for atmospheric as well as surface soil analysis, worked well on both landers. Atmospheric measurements resulted in the determination of the abundance of noble gases as well as of other molecular species. Isotopic composition measurements included the important ratios of C-13/C-12, N-15/N-14, and Ar-36/Ar-40. To verify these past results and to advance detailed studies of noble gas isotope ratios and minor constituents, better instrument sensitivities, higher precision, and lower background contributions are required in future Mars missions. Soil analysis during the Viking mission concentrated on organic material. Heating cycles were performed to 500 C and only water and carbon dioxide were identified. Higher pyrolysis temperatures are of primary importance to advance our understanding of the mineralogy and gas loading of surface material and atmospheric exchange.

Attributes from NMIS Time Coincidence, Fast-Neutron Imaging, Fission Mapping, And Gamma-Ray Spectrometry Data

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

Swift, Alicia L; Grogan, Brandon R; Mullens, James Allen

This work tests a systematic procedure for analyzing data acquired by the Nuclear Materials Identification System (NMIS) at Oak Ridge National Laboratory with fast-neutron imaging and high-purity germanium (HPGe) gamma spectrometry capabilities. NMIS has been under development by the US Department of Energy Office of Nuclear Verification since the mid-1990s, and prior to that by the National Nuclear Security Administration Y-12 National Security Complex, with NMIS having been used at Y-12 for template matching to confirm inventory and receipts. In this present work, a complete set of NMIS time coincidence, fast-neutron imaging, fission mapping, and HPGe gamma-ray spectrometry data wasmore » obtained from Monte Carlo simulations for a configuration of fissile and nonfissile materials. The data were then presented for analysis to someone who had no prior knowledge of the unknown object to accurately determine the description of the object by applying the previously-mentioned procedure to the simulated data. The best approximation indicated that the unknown object was composed of concentric cylinders: a void inside highly enriched uranium (HEU) (84.7 {+-} 1.9 wt % {sup 235}U), surrounded by depleted uranium, surrounded by polyethylene. The final estimation of the unknown object had the correct materials and geometry, with error in the radius estimates of material regions varying from 1.58% at best and 4.25% at worst; error in the height estimates varied from 2% to 12%. The error in the HEU enrichment estimate was 5.9 wt % (within 2.5{sigma} of the true value). The accuracies of the determinations could be adequate for arms control applications. Future work will apply this iterative reconstructive procedure to other unknown objects to further test and refine it.« less

Recent developments in the fabrication of ordered nanostructure arrays based on nanosphere lithography.

PubMed

Wei, Xueyong

2010-11-01

Since it was invented two decades ago, Nanosphere Lithography (NSL) has been widely studied as a low cost and flexible technique to fabricate nanostructures. Based on the registered patents and some selected papers, this review will discuss recent developments of different NSL strategies for the fabrication of ordered nanostructure arrays. The mechanism of self-assembly process and the techniques for preparing the self-assembled nanosphere template are first briefly introduced. The nanosphere templates are used either as shadow masks or as moulds for pattern transfer. Much more work now combines NSL with other lithographic techniques and material growth methods to form novel nanostructures of complex shape or various materials. Hence, this review finally gives a discussion on some future directions in NSL study.

GEM detector development for tokamak plasma radiation diagnostics: SXR poloidal tomography

NASA Astrophysics Data System (ADS)

Chernyshova, Maryna; Malinowski, Karol; Ziółkowski, Adam; Kowalska-Strzeciwilk, Ewa; Czarski, Tomasz; Poźniak, Krzysztof T.; Kasprowicz, Grzegorz; Zabołotny, Wojciech; Wojeński, Andrzej; Kolasiński, Piotr; Krawczyk, Rafał D.

2015-09-01

An increased attention to tungsten material is related to a fact that it became a main candidate for the plasma facing material in ITER and future fusion reactor. The proposed work refers to the studies of W influence on the plasma performances by developing new detectors based on Gas Electron Multiplier GEM) technology for tomographic studies of tungsten transport in ITER-oriented tokamaks, e.g. WEST project. It presents current stage of design and developing of cylindrically bent SXR GEM detector construction for horizontal port implementation. Concept to overcome an influence of constraints on vertical port has been also presented. It is expected that the detecting unit under development, when implemented, will add to the safe operation of tokamak bringing creation of sustainable nuclear fusion reactors a step closer.

Thermal Conductivity of Carbon Nanotube Composite Films

NASA Technical Reports Server (NTRS)

Ngo, Quoc; Cruden, Brett A.; Cassell, Alan M.; Walker, Megan D.; Koehne, Jessica E.; Meyyappan, M.; Li, Jun; Yang, Cary Y.

2004-01-01

State-of-the-art ICs for microprocessors routinely dissipate power densities on the order of 50 W/sq cm. This large power is due to the localized heating of ICs operating at high frequencies, and must be managed for future high-frequency microelectronic applications. Our approach involves finding new and efficient thermally conductive materials. Exploiting carbon nanotube (CNT) films and composites for their superior axial thermal conductance properties has the potential for such an application requiring efficient heat transfer. In this work, we present thermal contact resistance measurement results for CNT and CNT-Cu composite films. It is shown that Cu-filled CNT arrays enhance thermal conductance when compared to as-grown CNT arrays. Furthermore, the CNT-Cu composite material provides a mechanically robust alternative to current IC packaging technology.

Quantitative analysis of pulse thermography data for degradation assessment of historical buildings

NASA Astrophysics Data System (ADS)

Di Maio, Rosa; Piegari, Ester; Mancini, Cecilia; Chiapparino, Antonella

2015-06-01

In the last decades, infrared thermography has been successfully applied to various materials and structures for the assessment of their state of conservation and planning suitable restoration works. To this aim, mathematical models are required to characterize thermal anomaly sources, such as detachments, water infiltration and material decomposition processes. In this paper, an algorithm based on the conservative finite difference method is used to analyse pulse thermography data acquired on an ancient building in the Pompeii archaeological site (Naples, Italy). The numerical study is applied to both broad and narrow elongated thermal anomalies. In particular, from the comparison between simulated and experimental thermal decays, the plaster thickness was characterized in terms of thermal properties and areas of possible future detachments, and moisture infiltration depths were identified.

KSC-06pd0968

NASA Image and Video Library

2006-06-01

KENNEDY SPACE CENTER, FLA. - Inside the Space Station Processing Facility at NASA's Kennedy Space Center, an overhead crane carries the Columbus module away from its transportation canister. Columbus is the European Space Agency's research laboratory for the International Space Station. The module is being moved to a work stand to prepare it for delivery to the space station on a future space shuttle mission. Columbus will expand the research facilities of the station and provide researchers with the ability to conduct numerous experiments in the area of life, physical and materials sciences. Photo credit: NASA/Jim Grossmann

Microgravity

NASA Image and Video Library

2004-04-15

The manipulation of organic materials--cells, tissues, and even living organisms--offers many exciting possibilities for the future from organic computers to improved aquaculture. Commercial researchers are using the microgravity environment to produce large near perfect protein crystals Research on insulin has yielded crystals that far surpass the quality of insulin crystals grown on the ground. Using these crystals industry partners are working to develop new and improved treatments for diabetes. Other researchers are exploring the possibility of producing antibiotics using plant cell cultures which could lead to both orbital production and the improvement of ground-based antibiotic production.

Insulin

NASA Technical Reports Server (NTRS)

2004-01-01

The manipulation of organic materials--cells, tissues, and even living organisms--offers many exciting possibilities for the future from organic computers to improved aquaculture. Commercial researchers are using the microgravity environment to produce large near perfect protein crystals Research on insulin has yielded crystals that far surpass the quality of insulin crystals grown on the ground. Using these crystals industry partners are working to develop new and improved treatments for diabetes. Other researchers are exploring the possibility of producing antibiotics using plant cell cultures which could lead to both orbital production and the improvement of ground-based antibiotic production.

A review of nuclear thermal propulsion carbide fuel corrosion and key issues

NASA Technical Reports Server (NTRS)

Pelaccio, Dennis G.; El-Genk, Mohamed S.

1994-01-01

Corrosion (mass loss) of carbide nuclear fuels due to their exposure to hot hydrogen in nuclear thermal propulsion engine systems greatly impacts the performance, thrust-to-weight and life of such systems. This report provides an overview of key issues and processes associated with the corrosion of carbide materials. Additionally, past pertinent development reactor test observations, as well as related experimental work and analysis modeling efforts are reviewed. At the conclusion, recommendations are presented, which provide the foundation for future corrosion modeling and verification efforts.

How to Retrieve Information Inherent to Old Restorations Made on Frescoes of Particular Artistic Value Using Infrared Vision?

NASA Astrophysics Data System (ADS)

Sfarra, Stefano; Theodorakeas, Panagiotis; Ibarra-Castanedo, Clemente; Avdelidis, Nicolas P.; Ambrosini, Dario; Cheilakou, Eleni; Paoletti, Domenica; Koui, Maria; Bendada, Abdelhakim; Maldague, Xavier

2015-11-01

" Restoration is the methodological moment in which the artwork is appreciated in its material form and in its historical and aesthetic duality, with a view to transmitting it to the future" (C. Brandi). This work is inspired by this memorable definition. It is based both on the study of an ancient fresco and a fresco's reproduction, assessing the principal defects afflicting this type of structures and aiming at reconstructing the restoration phases through the definition of a combined thermographic and reflectographic procedure that has the purpose of mapping the quality of the restoration itself and thinking of the future. According to Brandi, the timeline for an artwork can be divided into three parts. The first corresponding to the duration of the creative process conducted by the artist and culminating with the completion of the work. The second corresponds to an interval, which is the historical time elapsing from the conclusion of the work to the present. Last but not least, the moment, which is acknowledged in the consciousness of the observer who takes the responsibility of transmitting it to the future. The observer might also be the restorer. Indeed, the restoration takes place at the latter stage and it aims at re-establishing the potential unity of the artwork, to the highest level possible, without producing an artistic or historical forgery and without erasing any trace of the natural passage of time on the artwork. The infrared vision might help to reveal whether the restoration is done properly or not.

Stress and suicidal ideation among adolescents having academic difficulty

PubMed Central

Arun, Priti; Garg, Rohit; Chavan, Bir Singh

2017-01-01

Background and Objectives: Academically typically achieving adolescents were compared with students having academic difficulty on stress and suicidal ideas. Materials and Methods: In a cross-sectional study, 75 academically typically achieving adolescents were compared with 105 students with academic difficulty and 52 students with specific learning disability (SLD). Academic functioning was assessed using teacher's screening instrument, intelligence quotient, and National Institute of Mental Health and Neurosciences index for SLD. Stress and suicidal ideas were assessed using general health questionnaire, suicide risk-11, and Mooney Problem Checklist (MPC). Appropriate statistical methods were applied. Results: Three groups were comparable on age, gender, mother's working status, being only child, nuclear family, self-reported academic decline, and type of school. About half of adolescents reported psychological problems on General Health Questionnaire (mean score >3 in all the groups). Academically typically achieving adolescents showed higher stressors in peer relationships, planning for future and suicidal ideation compared to adolescents with academic difficulty. Adolescents face stress regarding worry about examinations, family not understanding what child has to do in school, unfair tests, too much work in some subjects, afraid of failure in school work, not spending enough time in studies, parental expectations, wanting to be more popular, worried about a family member, planning for the future, and fear of the future. Significant positive correlation was seen between General Health Questionnaire scores and all four subscales of MPC. Suicidal ideas showed a negative correlation with MPC. Interpretations and Conclusions: Adolescents experience considerable stress in multiple areas irrespective of their academic ability and performance. Hence, assessment and management of stress among adolescents must extend beyond academic difficulties. PMID:29456324

Synthetically chemical-electrical mechanism for controlling large scale reversible deformation of liquid metal objects

PubMed Central

Zhang, Jie; Sheng, Lei; Liu, Jing

2014-01-01

Reversible deformation of a machine holds enormous promise across many scientific areas ranging from mechanical engineering to applied physics. So far, such capabilities are still hard to achieve through conventional rigid materials or depending mainly on elastomeric materials, which however own rather limited performances and require complicated manipulations. Here, we show a basic strategy which is fundamentally different from the existing ones to realize large scale reversible deformation through controlling the working materials via the synthetically chemical-electrical mechanism (SCHEME). Such activity incorporates an object of liquid metal gallium whose surface area could spread up to five times of its original size and vice versa under low energy consumption. Particularly, the alterable surface tension based on combination of chemical dissolution and electrochemical oxidation is ascribed to the reversible shape transformation, which works much more flexible than many former deformation principles through converting electrical energy into mechanical movement. A series of very unusual phenomena regarding the reversible configurational shifts are disclosed with dominant factors clarified. This study opens a generalized way to combine the liquid metal serving as shape-variable element with the SCHEME to compose functional soft machines, which implies huge potential for developing future smart robots to fulfill various complicated tasks. PMID:25408295

Synthetically chemical-electrical mechanism for controlling large scale reversible deformation of liquid metal objects.

PubMed

Zhang, Jie; Sheng, Lei; Liu, Jing

2014-11-19

Reversible deformation of a machine holds enormous promise across many scientific areas ranging from mechanical engineering to applied physics. So far, such capabilities are still hard to achieve through conventional rigid materials or depending mainly on elastomeric materials, which however own rather limited performances and require complicated manipulations. Here, we show a basic strategy which is fundamentally different from the existing ones to realize large scale reversible deformation through controlling the working materials via the synthetically chemical-electrical mechanism (SCHEME). Such activity incorporates an object of liquid metal gallium whose surface area could spread up to five times of its original size and vice versa under low energy consumption. Particularly, the alterable surface tension based on combination of chemical dissolution and electrochemical oxidation is ascribed to the reversible shape transformation, which works much more flexible than many former deformation principles through converting electrical energy into mechanical movement. A series of very unusual phenomena regarding the reversible configurational shifts are disclosed with dominant factors clarified. This study opens a generalized way to combine the liquid metal serving as shape-variable element with the SCHEME to compose functional soft machines, which implies huge potential for developing future smart robots to fulfill various complicated tasks.

Lubrication of Space Shuttle Main Engine Turbopump Bearings

NASA Technical Reports Server (NTRS)

Gibson, Howard; Munafo, Paul (Technical Monitor)

2001-01-01

The Space Shuttle has three main engines that are used for propulsion into orbit. These engines are fed propellants by four turbopumps on each engine. A main element in the turbopump is the bearings supporting the rotor that spins the turbine blades and the pump impeller. These bearings are required to spin at very high speeds, support radial and thrust loads, and have high wear resistance without the benefit of lubrication. The liquid hydrogen and oxygen propellants flow through the bearings to cool the surfaces. The volatile nature of the propellants excludes any conventional means of lubrication. Lubrication for these bearings is provided by the ball separator inside the bearing. The separator is a composite material that supplies a transfer film of lubrication to the rings and balls. New separator materials and lubrication schemes have been investigated at Marshall Space Flight Center in a bearing test rig with promising results. Hybrid bearings with silicon nitride balls have also been evaluated. The use of hybrid, silicon nitride ball bearings in conjunction -with better separator materials has shown excellent results. The work that Marshall has done is being utilized in turbopumps flying on the space shuttle fleet and will be utilized in future space travel. This result of this work is valuable for all aerospace and commercial applications where high-speed bearings are used.

Synthetically chemical-electrical mechanism for controlling large scale reversible deformation of liquid metal objects

NASA Astrophysics Data System (ADS)

Zhang, Jie; Sheng, Lei; Liu, Jing

2014-11-01

Reversible deformation of a machine holds enormous promise across many scientific areas ranging from mechanical engineering to applied physics. So far, such capabilities are still hard to achieve through conventional rigid materials or depending mainly on elastomeric materials, which however own rather limited performances and require complicated manipulations. Here, we show a basic strategy which is fundamentally different from the existing ones to realize large scale reversible deformation through controlling the working materials via the synthetically chemical-electrical mechanism (SCHEME). Such activity incorporates an object of liquid metal gallium whose surface area could spread up to five times of its original size and vice versa under low energy consumption. Particularly, the alterable surface tension based on combination of chemical dissolution and electrochemical oxidation is ascribed to the reversible shape transformation, which works much more flexible than many former deformation principles through converting electrical energy into mechanical movement. A series of very unusual phenomena regarding the reversible configurational shifts are disclosed with dominant factors clarified. This study opens a generalized way to combine the liquid metal serving as shape-variable element with the SCHEME to compose functional soft machines, which implies huge potential for developing future smart robots to fulfill various complicated tasks.

Materials Science

NASA Technical Reports Server (NTRS)

2003-01-01

The Materials Science Program is structured so that NASA s headquarters is responsible for the program content and selection, through the Enterprise Scientist, and MSFC provides for implementation of ground and flight programs with a Discipline Scientist and Discipline Manager. The Discipline Working Group of eminent scientists from outside of NASA acts in an advisory capacity and writes the Discipline Document from which the NRA content is derived. The program is reviewed approximately every three years by groups such as the Committee on Microgravity Research, the National Materials Advisory Board, and the OBPR Maximization and Prioritization (ReMaP) Task Force. The flight program has had as many as twenty-six principal investigators (PIs) in flight or flight definition stage, with the numbers of PIs in the future dependent on the results of the ReMaP Task Force and internal reviews. Each project has a NASA-appointed Project Scientist, considered a half-time job, who assists the PI in understanding and preparing for internal reviews such as the Science Concept Review and Requirements Definition Review. The Project Scientist also insures that the PI gets the maximum science support from MSFC, represents the PI to the MSFC community, and collaborates with the Project Manager to insure the project is well-supported and remains vital. Currently available flight equipment includes the Materials Science Research Rack (MSRR-1) and Microgravity Science Glovebox. Ground based projects fall into one or more of several categories. Intellectual Underpinning of Flight Program projects include theoretical studies backed by modeling and computer simulations; bring to maturity new research, often by young researchers, and may include preliminary short duration low gravity experiments in the KC-135 aircraft or drop tube; enable characterization of data sets from previous flights; and provide thermophysical property determinations to aid PIs. Radiation Shielding and preliminary In Situ Resource Utilization (ISRU) studies work towards future long duration missions. Biomaterials support materials issues affecting crew health. Nanostructured Materials are currently considered to be maturing new research, and Advanced Materials for Space Transportation has as yet no PIs. PIs are assigned a NASA Technical Monitor to maintain contact, a position considered to be a 5 percent per PI effort. Currently 33 PIs are supported on the 1996 NRA, which is about to expire, and 59 on the 1998 NRA. Two new NRAs, one for Radiation Shielding and one for Materials Science for Advanced Space Propulsion are due to be announced by the 2003 fiscal year. MSFC has a number of facilities supporting materials science. These include the Microgravity Development Laboratory/SD43; Electrostatic Levitator Facility; SCN Purification Facility; Electron Microscope/Microprobe Facility; Static and Rotating Magnetic Field Facility; X-Ray Diffraction Facility; and the Furnace Development Laboratory.

Application of Mobility Spectrum Analysis to Modern Multi-layered IR Device Material

NASA Astrophysics Data System (ADS)

Brown, Alexander Earl

Modern detector materials used for infrared (IR) imaging purposes contain complex multi-layered architectures, making more robust characterization techniques necessary. In order to determine mutli-carrier transport properties in the presence of mixed conduction, variable-field Hall characterization can be performed and then analyzed using mobility spectrum analysis to extract parameters of interest. Transport parameters are expected to aid in modeling and simulation of materials and can be used in optimization of particular problem areas. The performances of infrared devices ultimately depend on transport mechanisms, so an accurate determination becomes paramount. This work focuses on the characterization of two materials at the forefront of IR detectors; incumbent, tried and true, HgCdTe technologies and emergent III-V based superlattice structures holding much promise for future detector purposes. Ex-situ doped long-wave planar devices and in-situ doped mid-wave dual-layer heterojunctions (P+/n architecture) HgCdTe structures are explored with regards to substrate choice, namely lattice-matched CdZnTe and lattice-mismatched Si or GaAs. A detailed study of scattering mechanisms reveal that growth on lattice-mismatched substrates leads to dislocation scattering limited mobility at low temperature, correlating with extrinsically limited minority carrier lifetime and excesses diode tunneling current, resulting in overall lower performance. Mobility spectrum analysis proves to be an effective diagnostic on performance as well as providing insight in surface, substrate-interface, and minority carrier transport. Two main issues limiting performance of III-V based superlattices are addressed; high residual doping backgrounds and surface passivation. Mobility spectrum analysis proves to be a reliable method of determining background doping levels. Modest improvements are obtained via post-growth thermal annealing, but results suggest future efforts should be placed upon growth improvements. Passivation efforts using charged electret dielectric show promise but further refinements would be needed. Thiol passivation is identified as a successful passivant of Be-doped p-type InAs/GaSb long-wave absorbers using mobility spectrum analysis, correlating with fabricated device dark current. Mobility spectrum analysis demonstrates it will be indispensable in future development of III-V material.

Synthesis and Characterization of Stimuli Responsive Block Copolymers, Self-Assembly Behavior and Applications

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

Determan, Michael Duane

The central theme of this thesis work is to develop new block copolymer materials for biomedical applications. While there are many reports of stimuli-responsive amphiphilic [19-21] and crosslinked hydrogel materials [22], the development of an in situ gel forming, pH responsive pentablock copolymer is a novel contribution to the field, Figure 1.1 is a sketch of an ABCBA pentablock copolymer. The A blocks are cationic tertiary amine methacrylates blocked to a central Pluronic F127 triblock copolymer. In addition to the prerequisite synthetic and macromolecular characterization of these new materials, the self-assembled supramolecular structures formed by the pentablock were experimentally evaluated.more » This synthesis and characterization process serves to elucidate the important structure property relationships of these novel materials, The pH and temperature responsive behavior of the pentablock copolymer were explored especially with consideration towards injectable drug delivery applications. Future synthesis work will focus on enhancing and tuning the cell specific targeting of DNA/pentablock copolymer polyplexes. The specific goals of this research are: (1) Develop a synthetic route for gel forming pentablock block copolymers with pH and temperature sensitive properties. Synthesis of these novel copolymers is accomplished with ATRP, yielding low polydispersity and control of the block copolymer architecture. Well defined macromolecular characteristics are required to tailor the phase behavior of these materials. (2) Characterize relationship between the size and shape of pentablock copolymer micelles and gel structure and the pH and temperature of the copolymer solutions with SAXS, SANS and CryoTEM. (3) Evaluate the temperature and pH induced phase separation and macroscopic self-assembly phenomenon of the pentablock copolymer. (4) Utilize the knowledge gained from first three goals to design and formulate drug delivery formulations based on the multi-responsive properties of the pentablock copolymer. Demonstrate potential biomedical applications of these materials with in vitro drug release studies from pentablock copolymer hydrogels. The intent of this work is to contribute to the knowledge necessary for further tailoring of these, and other functional block copolymer materials for biomedical applications.« less

Future requirements for advanced materials

NASA Technical Reports Server (NTRS)

Olstad, W. B.

1980-01-01

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

Identification of Threshold Concepts for Biochemistry

PubMed Central

Green, David; Lewis, Jennifer E.; Lin, Sara; Minderhout, Vicky

2014-01-01

Threshold concepts (TCs) are concepts that, when mastered, represent a transformed understanding of a discipline without which the learner cannot progress. We have undertaken a process involving more than 75 faculty members and 50 undergraduate students to identify a working list of TCs for biochemistry. The process of identifying TCs for biochemistry was modeled on extensive work related to TCs across a range of disciplines and included faculty workshops and student interviews. Using an iterative process, we prioritized five concepts on which to focus future development of instructional materials. Broadly defined, the concepts are steady state, biochemical pathway dynamics and regulation, the physical basis of interactions, thermodynamics of macromolecular structure formation, and free energy. The working list presented here is not intended to be exhaustive, but rather is meant to identify a subset of TCs for biochemistry for which instructional and assessment tools for undergraduate biochemistry will be developed. PMID:25185234

Best practices for preventing musculoskeletal disorders in masonry: stakeholder perspectives.

PubMed

Entzel, Pamela; Albers, Jim; Welch, Laura

2007-09-01

Brick masons and mason tenders report a high prevalence of work-related musculoskeletal disorders (WMSDs), many of which can be prevented with changes in materials, work equipment or work practices. To explore the use of "best practices" in the masonry industry, NIOSH organized a 2-day meeting of masonry stakeholders. Attendees included 30 industry representatives, 5 health and safety researchers, 4 health/safety specialists, 2 ergonomic consultants, and 2 representatives of state workers' compensation programs. Small groups discussed ergonomic interventions currently utilized in the masonry industry, including factors affecting intervention implementation and ways to promote diffusion of interventions. Meeting participants also identified various barriers to intervention implementation, including business considerations, quality concerns, design issues, supply problems, jobsite conditions and management practices that can slow or limit intervention diffusion. To be successful, future diffusion efforts must not only raise awareness of available solutions but also address these practical concerns.

Accessing Synthetically-Challenging Isoindole-Based Materials for Assessment in Organic Photovoltaics via Chemical and Engineering Methodologies =

NASA Astrophysics Data System (ADS)

Dang, Jeremy

Isoindoles are a broad class of compounds that comprise a very small space within the domain of established photoactive materials for organic photovoltaics (OPVs). Given this scarcity, combined with the performance appeal of presently and well known isoindole-based compounds such as the phthalocyanines, it is a worthy undertaking to develop new materials in this domain. This thesis aims to bring to light the suitability of five novel, or underexplored, classes of isoindole-based materials for OPVs. These classes are the boron subphthalocyanine (BsubPc) polymers, oxygen-bridged dimers of BsubPcs (mu-oxo-(BsubPc) 2), boron subnaphthalocyanines (BsubNcs), group XIII metal complexes of 1,3-bis(2-pyridylimino)isodinoline (BPI), and the boron tribenzosubporphyrins (BsubPys). The synthesis of these materials was proven to be challenging as evident in their low isolated yields, lengthy synthetic and purification processes, and/or batch-to-batch variations. This outcome was not surprising given their undeveloped chemical nature. The photo- and electro-physical properties were characterized and shown to be desirable for all classes other than the group XIII metal complexes of BPI for OPVs. mu-Oxo-(BsubPc)2 and BsubNcs show promise in this application while BsubPc polymers and BsubPys will be subjects of future exploration. The results from the work herein aid to develop and strengthen the fundamental understanding of the structure-property relationships of isoindole derivatives. On a broader scale, the work demonstrates their versatility as functional materials for OPVs and their possible expansion to other organic electronic technologies like organic light emitting diodes and organic field effect transistors.

Engineers are from PDMS-land, Biologists are from Polystyrenia.

PubMed

Berthier, Erwin; Young, Edmond W K; Beebe, David

2012-04-07

As the integration of microfluidics into cell biology research proceeds at an ever-increasing pace, a critical question for those working at the interface of both disciplines is which device material to use for a given application. While PDMS and soft lithography methods offer the engineer rapid prototyping capabilities, PDMS as a material has characteristics that have known adverse effects on cell-based experiments. In contrast, while polystyrene (PS), the most commonly used thermoplastic for laboratory cultureware, has provided decades of grounded and validated research conclusions in cell behavior and function, PS as a material has posed significant challenges in microfabrication. These competing issues have forced microfluidics engineers and biologists to make compromises in how they approach specific research questions, and furthermore, have attenuated the impact of microfluidics on biological research. In this review, we provide a comparison of the attributes of PDMS and PS, and discuss reasons for their popularity in their respective fields. We provide a critical evaluation of the strengths and limitations of PDMS and PS in relation to the advancement and future impact on microfluidic cell-based studies and applications. We believe that engineers have a responsibility to overcome any challenges associated with microfabrication, whether with PS or other materials, and that engineers should provide options and solutions that assist biologists in their experimental design. Our goal is not to advocate for any specific material, but provide guidelines for researchers who desire to choose the most suitable material for their application, and suggest important research directions for engineers working at the interface between microfabrication technology and biological application. This journal is © The Royal Society of Chemistry 2012

3D printing with polymers: Challenges among expanding options and opportunities.

PubMed

Stansbury, Jeffrey W; Idacavage, Mike J

2016-01-01

Additive manufacturing, which is more colloquially referred to as 3D printing, is quickly approaching mainstream adoption as a highly flexible processing technique that can be applied to plastic, metal, ceramic, concrete and other building materials. However, taking advantage of the tremendous versatility associated with in situ photopolymerization as well as the ability to select from a variety of preformed processible polymers, 3D printing predominantly targets the production of polymeric parts and models. The goal of this review is to connect the various additive manufacturing techniques with the monomeric and polymeric materials they use while highlighting emerging material-based developments. Modern additive manufacturing technology was introduced approximately three decades ago but this review compiles recent peer-reviewed literature reports to demonstrate the evolution underway with respect to the various building techniques that differ significantly in approach as well as the new variations in polymer-based materials being employed. Recent growth of 3D printing has been dramatic and the ability of the various platform technologies to expand from rapid production prototypic models to the greater volume of readily customizable production of working parts is critical for continued high growth rates. This transition to working part production is highly dependent on adapting materials that deliver not only the requisite design accuracy but also the physical and mechanical properties necessary for the application. With the weighty distinction of being called the next industrial revolution, 3D printing technologies is already altering many industrial and academic operations including changing models for future healthcare delivery in medicine and dentistry. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

A miniaturized test method for the mechanical characterization of structural materials for fusion reactors

NASA Astrophysics Data System (ADS)

Gondi, P.; Donato, A.; Montanari, R.; Sili, A.

1996-10-01

This work deals with a non-destructive method for mechanical tests which is based on the indentation of materials at a constant rate by means of a cylinder with a small radius and penetrating flat surface. The load versus penetration depth curves obtained using this method have shown correspondences with those of tensile tests and have given indications about the mechanical properties on a reduced scale. In this work penetration tests have been carried out on various kinds of Cr martensitic steels (MANET-2, BATMAN and modified F82H) which are of interest for first wall and structural applications in future fusion reactors. The load versus penetration depth curves have been examined with reference to data obtained in tensile tests and to microhardness measurements. Penetration tests have been performed at various temperature (from -180 to 100°C). Conclusions, which can be drawn for the ductile to brittle transition, are discussed for MANET-2 steel. Preliminary results obtained on BATMAN and modified F82H steels are reported. The characteristics of the indenter imprints have been studied by scanning electron microscopy.

OLTARIS: On-Line Tool for the Assessment of Radiation in Space

NASA Technical Reports Server (NTRS)

Sandridge, Chris A.; Blattnig, Steve R.; Clowdsley, Martha S.; Norbury, John; Qualis, Garry D.; Simonsen, Lisa C.; Singleterry, Robert C.; Slaba, Tony C.; Walker, Steven A.; Badavi, Francis F.;

Characteristics of Early Work Experiences and Their Association with Future Employment

ERIC Educational Resources Information Center

McDonnall, Michele Capella; O'Mally, Jamie

2012-01-01

Introduction: Early work experiences are a key predictor of future employment for transition-age youths with visual impairments. We investigated how specific characteristics of early work experiences influence future employment and whether the receipt of Supplemental Security Income (SSI) benefits is associated with early work experiences among…

Overview of Research for Lunar Oxygen Processing at Carbotek Development Laboratories

NASA Astrophysics Data System (ADS)

Ortego, J. D., Jr.; Sorge, L. L.; Guo-Murray, M.; Gibson, M. A.; Knudsen, C. W.

1997-01-01

Oxygen production from indigenous lunar material is considered an enabling technology for future solar system exploration. Lunar derived oxygen provides many lunar base program enhancements. A great mass benefit can be derived when Earth return propellant oxidizer is not manifested for transit vehicles traveling to the moon. This results in substantial cost savings to the overall space transportation infrastructure. In addition, lunar produced oxygen can be used to supplement life support systems. Finally, many of the lunar oxygen processes under development produce by-products which are excellent construction materials, rich in iron and titanium, for shielding habitats and lunar surface equipment from cosmic radiation and more lethal solar flares. As a result of the apparent benefits of lunar derived oxygen, NASA has funded research for the development of promising techniques since the mid- 1980's in order for the technology to be available for lunar return missions. Carbotek, with funding and technical assistance f om NASA Johnson Space Center and the Shimizu Corporation, Space Systems Division, has been developing oxygen producing technology since 1984. This paper describes past and future work by Carbotek on two processes, hydrogen reduction of ilmenite and magma electrolysis.

Partial discharge characteristics of polymer nanocomposite materials in electrical insulation: a review of sample preparation techniques, analysis methods, potential applications, and future trends.

PubMed

Izzati, Wan Akmal; Arief, Yanuar Z; Adzis, Zuraimy; Shafanizam, Mohd

2014-01-01

Polymer nanocomposites have recently been attracting attention among researchers in electrical insulating applications from energy storage to power delivery. However, partial discharge has always been a predecessor to major faults and problems in this field. In addition, there is a lot more to explore, as neither the partial discharge characteristic in nanocomposites nor their electrical properties are clearly understood. By adding a small amount of weight percentage (wt%) of nanofillers, the physical, mechanical, and electrical properties of polymers can be greatly enhanced. For instance, nanofillers in nanocomposites such as silica (SiO2), alumina (Al2O3) and titania (TiO2) play a big role in providing a good approach to increasing the dielectric breakdown strength and partial discharge resistance of nanocomposites. Such polymer nanocomposites will be reviewed thoroughly in this paper, with the different experimental and analytical techniques used in previous studies. This paper also provides an academic review about partial discharge in polymer nanocomposites used as electrical insulating material from previous research, covering aspects of preparation, characteristics of the nanocomposite based on experimental works, application in power systems, methods and techniques of experiment and analysis, and future trends.

Critical Technologies for the Development of Future Space Elevator Systems

NASA Technical Reports Server (NTRS)

Smitherman, David V., Jr.

2005-01-01

A space elevator is a tether structure extending through geosynchronous earth orbit (GEO) to the surface of the earth. Its center of mass is in GEO such that it orbits the earth in sync with the earth s rotation. In 2004 and 2005, the NASA Marshall Space Flight Center and the Institute for Scientific Research, Inc. worked under a cooperative agreement to research the feasibility of space elevator systems, and to advance the critical technologies required for the future development of space elevators for earth to orbit transportation. The discovery of carbon nanotubes in the early 1990's was the first indication that it might be possible to develop materials strong enough to make space elevator construction feasible. This report presents an overview of some of the latest NASA sponsored research on space elevator design, and the systems and materials that will be required to make space elevator construction possible. In conclusion, the most critical technology for earth-based space elevators is the successful development of ultra high strength carbon nanotube reinforced composites for ribbon construction in the 1OOGPa range. In addition, many intermediate technology goals and demonstration missions for the space elevator can provide significant advancements to other spaceflight and terrestrial applications.

3-D Bioprinting of Neural Tissue for Applications in Cell Therapy and Drug Screening

PubMed Central

Thomas, Michaela; Willerth, Stephanie M.

2017-01-01

Neurodegenerative diseases affect millions of individuals in North America and cost the health-care industry billions of dollars for treatment. Current treatment options for degenerative diseases focus on physical rehabilitation or drug therapies, which temporarily mask the effects of cell damage, but quickly lose their efficacy. Cell therapies for the central nervous system remain an untapped market due to the complexity involved in growing neural tissues, controlling their differentiation, and protecting them from the hostile environment they meet upon implantation. Designing tissue constructs for the discovery of better drug treatments are also limited due to the resolution needed for an accurate cellular representation of the brain, in addition to being expensive and difficult to translate to biocompatible materials. 3-D printing offers a streamlined solution for engineering brain tissue for drug discovery or, in the future, for implantation. New microfluidic and bioplotting devices offer increased resolution, little impact on cell viability and have been tested with several bioink materials including fibrin, collagen, hyaluronic acid, poly(caprolactone), and poly(ethylene glycol). This review details current efforts at bioprinting neural tissue and highlights promising avenues for future work. PMID:29204424

Effect of Nanoparticle Incorporation and Surface Coating on Mechanical Properties of Bone Scaffolds: A Brief Review

PubMed Central

Corona-Gomez, Jesus; Chen, Xiongbiao; Yang, Qiaoqin

2016-01-01

Mechanical properties of a scaffold play an important role in its in vivo performance in bone tissue engineering, due to the fact that implanted scaffolds are typically subjected to stress including compression, tension, torsion, and shearing. Unfortunately, not all the materials used to fabricate scaffolds are strong enough to mimic native bones. Extensive research has been conducted in order to increase scaffold strength and mechanical performance by incorporating nanoparticles and/or coatings. An incredible improvement has been achieved; and some outstanding examples are the usage of nanodiamond, hydroxyapatite, bioactive glass particles, SiO2, MgO, and silver nanoparticles. This review paper aims to present the results, to summarize significant findings, and to give perspective for future work, which could be beneficial to future bone tissue engineering. PMID:27420104

Quantum technology past, present, future: quantum energetics (Conference Presentation)

NASA Astrophysics Data System (ADS)

Choi, Sang H.

2017-04-01

Since the development of quantum physics in the early part of the 1900s, this field of study has made remarkable contributions to our civilization. Some of these advances include lasers, light-emitting diodes (LED), sensors, spectroscopy, quantum dots, quantum gravity and quantum entanglements. In 1998, the NASA Langley Research Center established a quantum technology committee to monitor the progress in this area and initiated research to determine the potential of quantum technology for future NASA missions. The areas of interest in quantum technology at NASA included fundamental quantum-optics materials associated with quantum dots and quantum wells, device-oriented photonic crystals, smart optics, quantum conductors, quantum information and computing, teleportation theorem, and quantum energetics. A brief review of the work performed, the progress made in advancing these technologies, and the potential NASA applications of quantum technology will be presented.

The Aluminum Smelting Process and Innovative Alternative Technologies

PubMed Central

Drabløs, Per Arne

2014-01-01

Objective: The industrial aluminum production process is addressed. The purpose is to give a short but comprehensive description of the electrolysis cell technology, the raw materials used, and the health and safety relevance of the process. Methods: This article is based on a study of the extensive chemical and medical literature on primary aluminum production. Results: At present, there are two main technological challenges for the process—to reduce energy consumption and to mitigate greenhouse gas emissions. A future step may be carbon dioxide gas capture and sequestration related to the electric power generation from fossil sources. Conclusions: Workers' health and safety have now become an integrated part of the aluminum business. Work-related injuries and illnesses are preventable, and the ultimate goal to eliminate accidents with lost-time injuries may hopefully be approached in the future. PMID:24806723

The manufacturing, assembly and acceptance testing of the breadboard cryogenic Optical Delay Line for DARWIN

NASA Astrophysics Data System (ADS)

van den Dool, T. C.; Kamphues, F.; Gielesen, W.; Dorrepaal, M.; Doelman, N.; Loix, N.; Verschueren, J. P.; Kooijman, P. P.; Visser, M.; Velsink, G.; Fleury, K.

2005-08-01

TNO, in cooperation with Micromega-Dynamics, SRON, Dutch Space and CSL, has developed a compact breadboard cryogenic Optical Delay Line for use in future space interferometry missions. The work is performed under ESA contract in preparation for the DARWIN mission. The breadboard delay line is representative of a future flight mechanism, with all used materials and processes being flight representative. The delay line has a single stage voice coil actuator for Optical Path Difference (OPD) control, driving a two-mirror cat's eye. Magnetic bearings are used for guiding. They provide frictionless and wear free operation with zero-hysteresis. The manufacturing, assembly and acceptance testing have been completed and are reported in this paper. The verification program, including functional testing at 40 K, will start in the final quarter of 2005.

Simulation on the Performance of a Driven Fan Made by Polyester/Epoxy interpenetrate polymer network (IPN)

NASA Astrophysics Data System (ADS)

Fahrul Hassan, Mohd; Jamri, Azmil; Nawawi, Azli; Zaini Yunos, Muhamad; Fauzi Ahmad, Md; Adzila, Sharifah; Nasrull Abdol Rahman, Mohd

2017-08-01

The main purpose of this study is to investigate the performance of a driven fan design made by Polyester/Epoxy interpenetrate polymer network (IPN) material that specifically used for turbocharger compressor. Polyester/Epoxy IPN is polymer plastics that was used as replacements for traditional polymers and has been widely used in a variety of applications because of their limitless conformations. Simulation based on several parameters which are air pressure, air velocity and air temperature have been carried out for a driven fan design performance of two different materials, aluminum alloy (existing driven fan design) and Polyester/Epoxy IPN using SolidWorks Flow Simulation software. Results from both simulations were analyzed and compared where both materials show similar performance in terms of air pressure and air velocity due to similar geometric and dimension, but Polyester/Epoxy IPN produces lower air temperature than aluminum alloy. This study shows a preliminary result of the potential Polyester/Epoxy IPN to be used as a driven fan design material. In the future, further studies will be conducted on detail simulation and experimental analysis.

Materials and processing science: Limits for microelectronics

NASA Astrophysics Data System (ADS)

Rosenberg, R.

1988-09-01

The theme of this talk will be to illustrate examples of technologies that will drive materials and processing sciences to the limit and to describe some of the research being pursued to understand materials interactions which are pervasive to projected structure fabrication. It is to be expected that the future will see a progression to nanostructures where scaling laws will be tested and quantum transport will become more in evidence, to low temperature operation for tighter control and improved performance, to complex vertical profiles where 3D stacking and superlattices will produce denser packing and device flexibility, to faster communication links with optoelectronics, and to compatible packaging technologies. New low temperature processing techniques, such as epitaxy of silicon, PECVD of dielectrics, low temperature high pressure oxidation, silicon-germanium heterostructures, etc., must be combined with shallow metallurgies, new lithographic technologies, maskless patterning, rapid thermal processing (RTP) to produce needed profile control, reduce process incompatibilities and develop new device geometries. Materials interactions are of special consequence for chip substrates and illustrations of work in metal-ceramic and metal-polymer adhesion will be offered.

Examining the diagenetic alteration of human bone material from a range of archaeological burial sites using nuclear microscopy

NASA Astrophysics Data System (ADS)

Elliott, T. A.; Grime, G. W.

1993-05-01

The inorganic analysis of archaeological bone material can potentially provide a wealth of information about the chronology, diet and palaeoenvironment of past populations: for example, strontium and uranium levels are used in palaeodietary and dating studies, respectively. However, the extent to which the chemical composition of bone is subject to diagenetic change during burial is open to controversy due, in part, to differences in analytical technique, bone types and burial conditions. To investigate this problem, archaeological human bone material from a number of different geological environments including Pompeii and a 12th century British ecclesiastical site, together with material from two seawater burials (The "Mary Rose" and a 6th century Mediterranean wreck) have been studied using the nuclear microprobe facility at the University of Oxford. Results using microbeam PIXE show that bone is subject to contamination from a wide range of trace elements depending on the burial conditions. Elemental maps are presented to demonstrate the distribution of trace element accumulation under different burial conditions, and the significance of this work to future trace element studies is discussed.

Si-doping bone composite based on protein template-mediated assembly for enhancing bone regeneration

NASA Astrophysics Data System (ADS)

Yang, Qin; Du, Yingying; Wang, Yifan; Wang, Zhiying; Ma, Jun; Wang, Jianglin; Zhang, Shengmin

2017-06-01

Bio-inspired hybrid materials that contain organic and inorganic networks interpenetration at the molecular level have been a particular focus of interest on designing novel nanoscale composites. Here we firstly synthesized a series of hybrid bone composites, silicon-hydroxyapatites/silk fibroin/collagen, based on a specific molecular assembled strategy. Results of material characterization confirmed that silicate had been successfully doped into nano-hydroxyapatite lattice. In vitro evaluation at the cellular level clearly showed that these Si-doped composites were capable of promoting the adhesion and proliferation of rat mesenchymal stem cells (rMSCs), extremely enhancing osteoblastic differentiation of rMSCs compared with silicon-free composite. More interestingly, we found there was a critical point of silicon content in the composition on regulating multiple cell behaviors. In vivo animal evaluation further demonstrated that Si-doped composites enabled to significantly improve the repair of cranial bone defect. Consequently, our current work not only suggests fabricating a potential bone repair materials by integrating element-doping and molecular assembled strategy in one system, but also paves a new way for constructing multi-functional composite materials in the future.

Dielectric properties of novel polyurethane-PZT-graphite foam composites

NASA Astrophysics Data System (ADS)

Tolvanen, Jarkko; Hannu, Jari; Nelo, Mikko; Juuti, Jari; Jantunen, Heli

2016-09-01

Flexible foam composite materials offer multiple benefits to future electronic applications as the rapid development of the electronics industry requires smaller, more efficient, and lighter materials to further develop foldable and wearable applications. The aims of this work were to examine the electrical properties of three- and four-phase novel foam composites in different conditions, find the optimal mixture for four-phase foam composites, and study the combined effects of lead zirconate titanate (PZT) and graphite fillers. The flexible and highly compressible foams were prepared in a room-temperature mixing process using polyurethane, PZT, and graphite components as well as their combinations, in which air acted as one phase. In three-phase foams the amount of PZT varied between 20 and 80 wt% and the amount of graphite, between 1 and 15 wt%. The four-phase foams were formed by adding 40 wt% of PZT while the amount of graphite ranged between 1 and 15 wt%. The presented results and materials could be utilized to develop new flexible and soft sensor applications by means of material technology.

π-Extended triptycene-based material for capillary gas chromatographic separations.

PubMed

Yang, Yinhui; Wang, Qinsi; Qi, Meiling; Huang, Xuebin

2017-10-02

Triptycene-based materials feature favorable physicochemical properties and unique molecular recognition ability that offer good potential as stationary phases for capillary gas chromatography (GC). Herein, we report the investigation of utilizing a π-extended triptycene material (denoted as TQPP) for GC separations. As a result, the TQPP capillary column exhibited high column efficiency of 4030 plates m -1 and high-resolution performance for a wide range of analytes, especially structural and positional isomers. Interestingly, the TQPP stationary phase showed unique shape selectivity for alkanes isomers and preferential retention for analytes with halogen atoms and H-bonding nature mainly through their halogen-bonding and H-bonding interactions. In addition, the TQPP column had good repeatability and reproducibility with the RSD values of 0.02-0.34% for run-to-run, 0.09-0.80% for day-to-day and 1.4-5.2% for column-to-column, respectively, and favorable thermal stability up to 280 °C. This work demonstrates the promising future of triptycene-based materials as a new class of stationary phases for GC separations. Copyright © 2017 Elsevier B.V. All rights reserved.

Supplemental Journal Article Materials: A progress report on an information industry initiative

NASA Astrophysics Data System (ADS)

Schwarzman, A. B.

2011-12-01

Who could possibly quibble with the idea of publishing supplemental materials to a journal article? Making them available makes it possible for the Earth and space scientists to demonstrate supporting evidence, such as multimedia, computer programs, and datasets; gives the authors the opportunity to present in-depth studies that would not otherwise be available; and enables the readers to replicate experiments and verify their results. However, the scholarly publishing ecosystem is now being threatened by a veritable tsunami of supplemental materials that have to be peer reviewed, identified, described, and made discoverable and citeable; such materials also have to be archived, preserved, and perpetually converted to the contemporary formats to be available to a future researcher. Moreover, the readers often have no clear indication of how critical a particular supplemental material is to the scientific conclusions of the article and thus are not sure whether they should spend their time reading/viewing/running it. In some cases it is not even clear what the material actually supplements. While one segment of the research community argues that even more supplemental materials should be made available, another segment increasingly voices its concern stating categorically that a research article is not a data dump or an FTP site. From the publisher's perspective, dealing with supplemental materials in a responsible fashion is becoming an increasingly costly proposition. Faced with formidable challenges of managing supplemental materials, the information profession community in 2010 formed a joint NISO/NFAIS Working Group to develop Recommended Practices for curating supplemental materials during their life cycle, including but not limited to their selection, peer review, editing, production, presentation, providing context, identification, linking, citing, hosting, discovery, metadata and markup, packaging, accessibility, and preservation. The Recommended Practices also intend to address roles and responsibilities of authors, editors, peer reviewers, publishers, libraries, abstracting and indexing services, and official data centers and institutional repositories. Finally, the document is going to contain broad principles and detailed technical implementation related to metadata, linking, packaging, and accessibility of supplemental materials. In this presentation, a co-chair of the NISO/NFAIS Working Group will report on the Group's latest progress in developing the Recommended Practices for Supplemental Journal Article Materials.

Electrorecycling of Critical and Value Metals from Mobile Electronics

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

Tedd E. Lister; Peming Wang; Andre Anderko

2014-09-01

Mobile electronic devices such as smart phones and tablets are a significant source of valuable metals that should be recycled. Each year over a billion devices are sold world-wide and the average life is only a couple years. Value metals in phones are gold, palladium, silver, copper, cobalt and nickel. Devices now contain increasing amounts of rare earth elements (REE). In recent years the supply chain for REE has moved almost exclusively to China. They are contained in displays, speakers and vibrators within the devices. By US Department of Energy (DOE) classification, specific REEs (Nd, Dy, Eu, Tb and Y)more » are considered critical while others (Ce, La and Pr) are deemed near critical. Effective recycling schemes should include the recovery of these critical materials. By including more value materials in a recovery scheme, more value can be obtained by product diversification and less waste metals remains to be disposed of. REEs are mined as a group such that when specific elements become critical significantly more ore must be processed to capture the dilute but valuable critical elements. Targeted recycling of items containing the more of the less available critical materials could address their future criticality. This presentation will describe work in developing aqueous electrochemistry-based schemes for recycling metals from scrap mobile electronics. The electrorecycling process generates oxidizing agents at an anode while reducing dissolved metals at the cathode. E vs pH diagrams and metals dissolution experiments are used to assess effectiveness of various solution chemistries. Although several schemes were envisioned, a two stages process has been the focus of work: 1) initial dissolution of Cu, Sn, Ag and magnet materials using Fe+3 generated in acidic sulfate and 2) final dissolution of Pd and Au using Cl2 generated in an HCl solution. Experiments were performed using simulated metal mixtures. Both Cu and Ag were recovered at ~ 97% using Fe+3 while leaving Au and Ag intact. REE were extracted from the dissolved mixture using conventional methods. A discussion of future research directions will be discussed.« less

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

Flanagan, Gene; Johnson, Rolland

High field superconducting magnets are used in particle colliders, fusion energy devices, and spectrometers for medical imaging and advanced materials research. Magnets capable of generating fields of 20-30 T are needed by future accelerator facilities. A 20-30 T magnet will require the use of high-temperature superconductors (HTS) and therefore the challenges of high field HTS magnet development need to be addressed. Superconducting Bi 2Sr 2CaCu 2O x (Bi2212) conductors fabricated by the oxide-powder-in-tube (OPIT) technique have demonstrated the capability to carry large critical current density of 10 5 A/cm 2 at 4.2 K and in magnetic fields up to 45more » T. Available in round wire multi-filamentary form, Bi2212 may allow fabrication of 20-50 T superconducting magnets. Until recently the performance of Bi2212 has been limited by challenges in realizing high current densities (J c ) in long lengths. This problem now is solved by the National High Magnetic Field Lab using an overpressure (OP) processing technique, which uses external pressure to process the conductor. OP processing also helps remove the ceramic leakage that results when Bi-2212 liquid leaks out from the sheath material and reacts with insulation, coil forms, and flanges. Significant advances have also been achieved in developing novel insulation materials (TiO 2 coating) and Ag-Al sheath materials that have higher mechanical strengths than Ag-0.2wt.% Mg, developing heat treatment approaches to broadening the maximum process temperature window, and developing high-strength, mechanical reinforced Bi-2212 cables. In the Phase I work, we leveraged these new opportunities to prototype overpressure processed solenoids and test them in background fields of up to 14 T. Additionally a design of a fully superconducting 30 T solenoid was produced. This work in conjunction with the future path outlined in the Phase II proposal would provide a major step toward qualifying Bi2212 technology for use in high-field accelerator magnets. Additionally, the performance parameters match key requirements of a final muon beam cooling solenoid. This technology will also be of interest to high-field NMR manufacturers.« less

Deposition in St. Mark's Basilica of Venice.

PubMed

Morabito, E; Zendri, E; Piazza, R; Ganzerla, R; Montalbani, S; Marcoleoni, E; Bonetto, F; Scandella, A; Barbante, C; Gambaro, A

2013-04-01

Atmospheric pollutants may cause damage to monuments and historical buildings. Besides air contaminants, soluble salts are also responsible for stone deterioration and decay in outdoor and indoor monuments. The problem of how to conserve works of arts thus requires a deep knowledge of contaminants' concentration and distribution inside buildings. In this work, water-soluble ions inside St. Mark's Basilica in Venice were studied, with the aim of understanding their principal source and distribution inside the building. With the aid of Fourier transform infrared spectroscopy and scanning electron microscopy analysis, the interaction between ions and surface's material was also investigated. Ion chromatographic analysis of depositions highlighted a large amount of "deteriorating agents" such as sulphates and chlorides. A possible source in the innermost area of the basilica has been found for formates and nitrates. On the contrary, a decrease of chloride, from the entrance to the innermost area, has been found, which indicates that the source is outside the building. It is emphasized that different contaminants behave differently on different material, and the effect of pollution inside churches and monuments is not easy to predict. Wood and brick seem to react differently than stone and mortar to the damaging action of salts and pollutants. The present work should be considered a useful tool for the future preservation of St. Mark's Basilica in Venice.

Shock Waves and Defects in Energetic Materials, a Match Made in MD Heaven

NASA Astrophysics Data System (ADS)

Wood, Mitchell; Kittell, David; Yarrington, Cole; Thompson, Aidan

2017-06-01

Shock wave interactions with defects, such as pores, are known to play a key role in the chemical initiation of energetic materials. In this talk the shock response of Hexanitrostilbene (HNS) is studied through large scale reactive molecular dynamics (RMD) simulations. These RMD simulations provide a unique opportunity to elucidate mechanisms of viscoplastic pore collapse which are often neglected in larger scale hydrodynamic models. A discussion of the macroscopic effects of this viscoplastic material response, such as its role in hot spot formation and eventual initiation, will be provided. Through this work we have been able to map a transition from purely viscoplastic to fluid-like pore collapse that is a function of shock strength, pore size and material strength. In addition, these findings are important reference data for the validation of future multi-scale modeling efforts of the shock response of heterogeneous materials. Examples of how these RMD results are translated into mesoscale models will also be addressed. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US DOE NNSA under Contract No. DE- AC04-94AL85000.

Flexible Piezoelectric Generators by Using the Bending Motion Method of Direct-Grown-PZT Nanoparticles on Carbon Nanotubes.

PubMed

Han, Jin Kyu; Jeon, Do Hyun; Cho, Sam Yeon; Kang, Sin Wook; Lim, Jongsun; Bu, Sang Don

2017-10-07

Recently, composite-type nanogenerators (NGs) formed from piezoelectric nanostructures and multi-walled carbon nanotubes (CNTs), have become one of the excellent candidates for future energy harvesting because of their ability to apply the excellent electrical and mechanical properties of CNTs. However, the synthesis of NG devices with a high proportion of piezoelectric materials and a low polymer content, such as of polydimethylsiloxane (PDMS), continues to be problematic. In this work, high-piezoelectric-material-content flexible films produced from Pb(Zr,Ti)O₃ (PZT)-atomically-interconnected CNTs and polytetrafluoroethylene (PTFE) are presented. Various physical and chemical characterization techniques are employed to examine the morphology and structure of the materials. The direct growth of the piezoelectric material on the CNTs, by stirring the PZT and CNT mixed solution, results in various positive effects, such as a high-quality dispersion in the polymer matrix and addition of flexoelectricity to piezoelectricity, resulting in the enhancement of the output voltage by an external mechanical force. The NGs repeatedly generate an output voltage of 0.15 V. These results present a significant step toward the application of NGs using piezoelectric nanocomposite materials.

Geo-material microfluidics at reservoir conditions for subsurface energy resource applications.

PubMed

Porter, Mark L; Jiménez-Martínez, Joaquín; Martinez, Ricardo; McCulloch, Quinn; Carey, J William; Viswanathan, Hari S

2015-10-21

Microfluidic investigations of flow and transport in porous and fractured media have the potential to play a significant role in the development of future subsurface energy resource technologies. However, the majority of experimental systems to date are limited in applicability due to operating conditions and/or the use of engineered material micromodels. We have developed a high pressure and temperature microfluidic experimental system that allows for direct observations of flow and transport within geo-material micromodels (e.g. rock, cement) at reservoir conditions. In this manuscript, we describe the experimental system, including our novel micromodel fabrication method that works in both geo- and engineered materials and utilizes 3-D tomography images of real fractures as micromodel templates to better represent the pore space and fracture geometries expected in subsurface formations. We present experimental results that highlight the advantages of using real-rock micromodels and discuss potential areas of research that could benefit from geo-material microfluidic investigations. The experiments include fracture-matrix interaction in which water imbibes into the shale rock matrix from etched fractures, supercritical CO2 (scCO2) displacing brine in idealized and realistic fracture patterns, and three-phase flow involving scCO2-brine-oil.

Impacts of air pollution on cultural heritage corrosion at European level: What has been achieved and what are the future scenarios.

PubMed

Di Turo, Francesca; Proietti, Chiara; Screpanti, Augusto; Fornasier, M Francesca; Cionni, Irene; Favero, Gabriele; De Marco, Alessandra

2016-11-01

The interaction of pollutants with Cultural Heritage materials leads to artworks and materials degradation and loss, causing an unpriceless damage. This works aims to estimate the impacts of air pollution and meteorological conditions on limestone, copper and bronze and represents the European risk assessment for corrosion of Cultural Heritage materials. The measures and policies for atmospheric pollution reduction have cut off the SO 2 concentration and consequently its impact on materials is drastically reduced. Indeed, in 1980 the number of UNESCO sites in danger was extremely high (94% for limestone, 54% for copper and 1% for bronze) while in 2010 these sites did not exceed the tolerable value of surface recession and corrosion. However, some problem related to air pollution persists. In particular, Random Forest Analysis (RFA), highlights PM 10 as the main responsible for materials corrosion, in 2010. Two scenarios in 2030 have been tested, highlighting that the corrosion levels of limestone, copper and bronze exceed the tolerable limits only in the Balkan area and Turkey. Our results show the importance in the air quality modelling as a powerful tool for the UNESCO sites conservation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Impact Resistance of Lightweight Hybrid Structures for Gas Turbine Engine Fan Containment Applications

NASA Technical Reports Server (NTRS)

Hebsur, Mohan G.; Noebe, Ronald D.; Revilock, Duane M.

2003-01-01

The ballistic impact resistance of hybrid composite sandwich structures was evaluated with the ultimate goal of developing new materials or structures for potential gas turbine engine fan containment applications. The sandwich structures investigated consisted of GLARE-5 laminates as face sheets with lightweight cellular metallic materials such as honeycomb, foam, and lattice block as a core material. The impact resistance of these hybrid sandwich structures was compared to GLARE-5 laminates and 2024-T3 Al sheet, which were tested as a function of areal weight (material thickness). The GLARE-5 laminates exhibited comparable impact properties to that of 2024-T3 Al at low areal weights, even though there were significant differences in the static tensile properties of these materials. The GLARE-5, however, did have a greater ballistic limit than straight aluminum sheet at higher areal weights. Furthermore, there is up to a 25% advantage in ballistic limit for the GLARE-5/foam sandwich structures compared to straight 2024-T3 Al. But no advantage in ballistic limit was observed between any of the hybrid sandwich structures and thicker versions of GLARE-5. Recommendations for future work are provided, based on these preliminary data.

Nano- and microstructured materials for in vitro studies of the physiology of vascular cells

PubMed Central

Chen, Hao; Biela, Sarah A; Kaufmann, Dieter

2016-01-01

The extracellular environment of vascular cells in vivo is complex in its chemical composition, physical properties, and architecture. Consequently, it has been a great challenge to study vascular cell responses in vitro, either to understand their interaction with their native environment or to investigate their interaction with artificial structures such as implant surfaces. New procedures and techniques from materials science to fabricate bio-scaffolds and surfaces have enabled novel studies of vascular cell responses under well-defined, controllable culture conditions. These advancements are paving the way for a deeper understanding of vascular cell biology and materials–cell interaction. Here, we review previous work focusing on the interaction of vascular smooth muscle cells (SMCs) and endothelial cells (ECs) with materials having micro- and nanostructured surfaces. We summarize fabrication techniques for surface topographies, materials, geometries, biochemical functionalization, and mechanical properties of such materials. Furthermore, various studies on vascular cell behavior and their biological responses to micro- and nanostructured surfaces are reviewed. Emphasis is given to studies of cell morphology and motility, cell proliferation, the cytoskeleton and cell-matrix adhesions, and signal transduction pathways of vascular cells. We finalize with a short outlook on potential interesting future studies. PMID:28144512

The Advanced Industrial Materials (AIM) program office of industrial technologies fiscal year 1995

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

Sorrell, C.A.

1997-04-01

In many ways, the Advanced Industrial Materials (AIM) Program underwent a major transformation in FY95 and these changes have continued to the present. When the Program was established in 1990 as the Advanced Industrial Concepts (AIC) Materials Program, the mission was to conduct applied research and development to bring materials and processing technologies from the knowledge derived from basic research to the maturity required for the end use sectors for commercialization. In 1995, the Office of Industrial Technologies (OIT) made radical changes in structure and procedures. All technology development was directed toward the seven `Vision Industries` that use about 80%more » of industrial energy and generated about 90% of industrial wastes. These are: aluminium; chemical; forest products; glass; metal casting; refineries; and steel. OIT is working with these industries, through appropriate organizations, to develop Visions of the desired condition of each industry some 20 to 25 years in the future and then to prepare Road Maps and Implementation Plans to enable them to reach their goals. The mission of AIM has, therefore, changed to `Support development and commercialization of new or improved materials to improve productivity, product quality, and energy efficiency in the major process industries.`« less

Space qualification of silicon carbide for mirror applications: progress and future objectives

NASA Astrophysics Data System (ADS)

Palusinski, Iwona A.; Ghozeil, Isaac

2006-09-01

Production of optical silicon carbide (SiC) for mirror applications continues to evolve and there are renewed plans to use this material in future space-based systems. While SiC has the potential for rapid and cost-effective manufacturing of large, lightweight, athermal optical systems, this material's use in mirror applications is relatively new and has limited flight heritage. This combination of drivers stresses the necessity for a space qualification program for this material. Successful space qualification will require independent collaboration to absorb the high cost of executing this program while taking advantage of each contributing group's laboratory expertise to develop a comprehensive SiC database. This paper provides an overview of the trends and progress in the production of SiC, and identifies future objectives such as non-destructive evaluation and space-effects modeling to ensure proper implementation of this material into future space-based systems.

Diagnostics of Carbon Nanotube Formation in a Laser Produced Plume: An Investigation of the Metal Catalyst by Laser Ablation Atomic Fluorescence Spectroscopy

NASA Technical Reports Server (NTRS)

deBoer, Gary; Scott, Carl

2003-01-01

Carbon nanotubes, elongated molecular tubes with diameters of nanometers and lengths in microns, hold great promise for material science. Hopes for super strong light-weight material to be used in spacecraft design is the driving force behind nanotube work at JSC. The molecular nature of these materials requires the appropriate tools for investigation of their structure, properties, and formation. The mechanism of nanotube formation is of particular interest because it may hold keys to controlling the formation of different types of nanotubes and allow them to be produced in much greater quantities at less cost than is currently available. This summer's work involved the interpretation of data taken last summer and analyzed over the academic year. The work involved diagnostic studies of carbon nanotube formation processes occurring in a laser-produced plume. Laser ablation of metal doped graphite to produce a plasma plume in which carbon nanotubes self assemble is one method of making carbon nanotube. The laser ablation method is amenable to applying the techniques of laser spectroscopy, a powerful tool for probing the energies and dynamics of atomic and molecular species. The experimental work performed last summer involved probing one of the metal catalysts, nickel, by laser induced fluorescence. The nickel atom was studied as a function of oven temperature, probe laser wavelength, time after ablation, and position in the laser produced plume. This data along with previously obtained data on carbon was analyzed over the academic year. Interpretations of the data were developed this summer along with discussions of future work. The temperature of the oven in which the target is ablated greatly influences the amount of material ablated and the propagation of the plume. The ablation conditions and the time scale of atomic and molecular lifetimes suggest that initial ablation of the metal doped carbon target results in atomic and small molecular species. The metal atoms survive for several milliseconds while the gaseous carbon atoms and small molecules nucleate more rapidly. Additional experiments and the development of in situ methods for carbon nanotube detection would allow these results to be interpreted from the perspective of carbon nanotube formation.

The development of thermoplastic fibre based reinforcements for the rotational moulding process

NASA Astrophysics Data System (ADS)

Alemán, D. N. Castellanos; McCourt, M.; Kearns, M. P.; Martin, P. J.; Butterfield, J.

2018-05-01

Rotational moulding is a method used to produce hollow plastic parts through the heating, melting and cooling of polymer powder within a metal mould. A wide range of products are made using this process, such as fluid containment tanks, boats, light weight vehicle bodies and marine buoys. Rotomoulded composites using thermoplastic fibres are of increasing interest to the industry, as they have the potential to significantly improve impact strength, whilst reducing part weight, resulting in a structure that is 100% recyclable compared to a traditional composite. A series of self-reinforced thermoplastic weaves can be used to produce a number of composite structures using the rotational moulding process. This work outlines the improvements obtained from the range of rotomoulded composites structures, as well as preforms that could be used in future rotational moulding work. Characteristics of self-reinforced materials were exploited with the aim of increasing the mechanical properties, preserving the weaves and increasing the nature of the material adhesion. Addition of the fabrics in the cooling stage was shown to be of great interest as this avoided exposure of the material to the peak temperature, which may affect the integrity of the fabric. Placing the weave during cooling was useful as the material could receive the maximum amount of tensile force during the impact test. A total of nine diverse types of compounds were manufactured and tested, with seven of the impact tests showing an increase in strength greater than 50%.

Double Shock Experiments and Reactive Flow Modeling on LX-17 to Understand the Reacted Equation of State

NASA Astrophysics Data System (ADS)

Vandersall, Kevin; Garcia, Frank; Fried, Laurence; Tarver, Craig

2013-06-01

Experimental data from measurements of the reacted state of an energetic material are desired to incorporate reacted states in modeling by computer codes. In a case such as LX-17 (92.5% TATB and 7.5% Kel-F by weight), where the time dependent kinetics of reaction is still not fully understood and the reacted state may evolve over time, this information becomes even more vital. Experiments were performed to measure the reacted state of LX-17 using a double shock method involving the use of two flyer materials (with known properties) mounted on the projectile that send an initial shock through the material close to or above the Chapman-Jouguet (CJ) state followed by a second shock at a higher magnitude into the detonated material. By measuring the parameters of the first and second shock waves, information on the reacted state can be obtained. The LX-17 detonation reaction zone profiles plus the arrival times and amplitudes of reflected shocks in LX-17 detonation reaction products were measured using Photonic Doppler Velocimetry (PDV) probes and an aluminum foil coated LiF window. A discussion of this work will include the experimental parameters, velocimetry profiles, data interpretation, reactive CHEETAH and Ignition and Growth modeling, as well as possible future experiments. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Usefulness of Interprofessional Education (Tsurumai-Meijo IPE) in Program Collaborating with Simulated Patients.

PubMed

Goto, Aya; Hanya, Manako; Yoshimi, Akira; Uchida, Mizuki; Takeuchi, Saori; Aida, Nobuko; Suematsu, Mina; Abe, Keiko; Yasui, Hiroki; Kamei, Hiroyuki; Noda, Yukihiro

2017-01-01

Collaboration with multiple healthcare professionals is important to provide safer and higher quality care. Interprofessional education (IPE) promotes the practice of team-based care. The establishment of Tsurumai-Meijo IPE, including interprofessional education and practice (IPEP) and video-teaching materials, was conducted in collaboration with school of medicine/nursing in Nagoya University and Fujita Health University, because Meijo University does not have its own clinical settings and faculties except for pharmacy. In the established Tsurumai-Meijo IPE, pharmacy, medicine, and nursing students interviewed simulated patients (SP) together or separately and practiced team-based care through Tsurumai-Meijo IPEP. Students could learn in advance and on their own about each professional's knowledge related to patient care by using video-teaching materials from the Meijo IPE homepage. Using a questionnaire survey at the end of program, this study was examined whether Tsurumai-Meijo IPEP, and video-teaching materials were useful for understanding importance of team-based care. More than 83% of students indicated that Tsurumai-Meijo IPE is useful on future clinical practice. This suggests that the program and materials are beneficial to the medical student education. In the optional survey of some clinical pharmacists, who had participated in Tsurumai-Meijo IPE before graduation, they utilized it in their work and it facilitated their work related to team-based care. Tsurumai-Meijo IPE collaborating with SP is likely to contribute to provide high quality and safe team-based care by taking advantage of specialized professional ability of healthcare professionals.

Characterization of an electrothermal plasma source for fusion transient simulations

NASA Astrophysics Data System (ADS)

Gebhart, T. E.; Baylor, L. R.; Rapp, J.; Winfrey, A. L.

2018-01-01

The realization of fusion energy requires materials that can withstand high heat and particle fluxes at the plasma material interface. In this work, an electrothermal (ET) plasma source has been designed as a transient heat flux source for a linear plasma material interaction device. An ET plasma source operates in the ablative arc regime driven by a DC capacitive discharge. The current channel width is defined by the 4 mm bore of a boron nitride liner. At large plasma currents, the arc impacts the liner wall, leading to high particle and heat fluxes to the liner material, which subsequently ablates and ionizes. This results in a high density plasma with a large unidirectional bulk flow out of the source exit. The pulse length for the ET source has been optimized using a pulse forming network to have durations of 1 and 2 ms. The peak currents and maximum source energies seen in this system are 1.9 kA and 1.2 kJ for the 2 ms pulse and 3.2 kA and 2.1 kJ for the 1 ms pulse, respectively. This work is a proof of the principal project to show that an ET source produces electron densities and heat fluxes comparable to those anticipated in transient events in large future magnetic confinement fusion devices. Heat flux, plasma temperature, and plasma density were determined for each shot using infrared imaging and optical spectroscopy techniques. This paper will discuss the assumptions, methods, and results of the experiments.

National Rocket Propulsion Materials Plan: A NASA, Department of Defense, and Industry Partnership

NASA Technical Reports Server (NTRS)

Clinton, Raymond G., Jr.; Munafo, Paul M. (Technical Monitor)

2001-01-01

NASA, Department of Defense, and rocket propulsion industry representatives are working together to create a national rocket propulsion materials development roadmap. This "living document" will facilitate collaboration among the partners, leveraging of resources, and will be a highly effective tool for technology development planning. The structuring of the roadmap, and development plan, which will combine the significant efforts of the Integrated High Payoff Rocket Propulsion Technology (IHPRPT) Program, and NASA's Integrated Space Transportation Plan (ISTP), is being lead by the IHPRPT Materials Working Group (IMWG). The IHPRPT Program is a joint DoD, NASA, and industry effort to dramatically improve the nation's rocket propulsion capabilities. This phased program is structured with increasingly challenging goals focused on performance, reliability, and cost to effectively double rocket propulsion capabilities by 2010. The IHPRPT program is focused on three propulsion application areas: Boost and Orbit Transfer (both liquid rocket engines and solid rocket motors), Tactical, and Spacecraft. Critical to the success of this initiative is the development and application of advanced materials, processes, and manufacturing technologies. NASA's ISTP is a comprehensive strategy focusing on the aggressive safety, reliability, and affordability goals for future space transportation systems established by the agency. Key elements of this plan are the 2 nd and 3 d Generation Reusable Launch Vehicles (RLV). The affordability and safety goals of these generational systems are, respectively, 10X cheaper and 100X safer by 2010, and 100X cheaper and 10,000X safer by 2025. Accomplishment of these goals requires dramatic and sustained breakthroughs, particularly in the development and the application of advanced material systems. The presentation will provide an overview of the IHPRPT materials initiatives, NASA's 2nd and 3 rd Generation RLV propulsion materials projects, and the approach for the development of the national rocket propulsion materials roadmap.

Detection of Organic Matter in Greenland Ice Cores by Deep-UV Fluorescence

NASA Astrophysics Data System (ADS)

Willis, M.; Malaska, M.; Wanger, G.; Bhartia, R.; Eshelman, E.; Abbey, W.; Priscu, J. C.

2017-12-01

The Greenland Ice Sheet is an Earthly analog for icy ocean worlds in the outer Solar System. Future missions to such worlds including Europa, Enceladus, and Titan may potentially include spectroscopic instrumentation to examine the surface/subsurface. The primary goal of our research is to test deep UV/Raman systems for in the situ detection and localization of organics in ice. As part of this effort we used a deep-UV fluorescence instrument able to detect naturally fluorescent biological materials such as aromatic molecules found in proteins and whole cells. We correlated these data with more traditional downstream analyses of organic material in natural ices. Supraglacial ice cores (2-4 m) were collected from several sites on the southwest outlet of the Greenland Ice Sheet using a 14-cm fluid-free mechanical coring system. Repeat spectral mapping data were initially collected longitudinally on uncut core sections. Cores were then cut into 2 cm thick sections along the longitudinal axis, slowly melted and analyzed for total organic carbon (TOC), total dissolved nitrogen (TDN), and bacterial density. These data reveal a spatial correlation between organic matter concentration, cell density, and the deep UV fluorescence maps. Our results provide a profile of the organics embedded within the ice from the top surface into the glacial subsurface, and the TOC:TDN data from the clean interior of the cores are indicative of a biological origin. This work provides a background dataset for future work to characterize organic carbon in the Greenland Ice Sheet and validation of novel instrumentation for in situ data collection on icy bodies.

Material Characterization of Microsphere-Based Scaffolds with Encapsulated Raw Materials

PubMed Central

Sridharan, BanuPriya; Mohan, Neethu; Berkland, Cory J.; Detamore, Michael S.

2016-01-01

“Raw materials,” or materials capable of serving both as building blocks and as signals, which are often but not always natural materials, are taking center stage in biomaterials for contemporary regenerative medicine. In osteochondral tissue engineering, a field leveraging the underlying bone to facilitate cartilage regeneration, common raw materials include chondroitin sulfate (CS) for cartilage and β-tricalcium phosphate (TCP) for bone. Building on our previous work with gradient scaffolds based on microspheres, here we delved deeper into the characterization of individual components. In the current study, the release of CS and TCP from poly(D,L-lactic-co-glycolic acid) (PLGA) microsphere-based scaffolds was evaluated over a time period of 4 weeks. Raw material encapsulated groups were compared to ‘blank’ groups and evaluated for surface topology, molecular weight, and mechanical performance as a function of time. The CS group may have led to increased surface porosity, and the addition of CS improved the mechanical performance of the scaffold. The finding that CS was completely released into the surrounding media by 4 weeks has a significant impact on future in vivo studies, given rapid bioavailability. The addition of TCP seemed to contribute to the rough external appearance of the scaffold. The current study provides an introduction to degradation patterns of homogenous raw material encapsulated scaffolds, providing characterization data to advance the field of microsphere-based scaffolds in tissue engineering. PMID:27040236

Development of W-composites/EUROFER brazed joints for the first wall component of future fusion reactors

NASA Astrophysics Data System (ADS)

de Prado, J.; Sánchez, M.; Antusch, S.; Ureña, A.

2017-12-01

The present work describes a joining procedure between two different tungsten composite materials (W-2Y2O3 and W-1TiC) with reduced activation ferritic-martensitic steel (Eurofer). The results indicated the achievement, in both cases, of high quality W-composites/Eurofer joints using 80Cu-20Ti as filler material. The braze is constituted by several ternary Cu-Ti-Fe phases distributed along a Cu-matrix, which acts as ductile phase capable of relieving the residual stresses, which could be produced during the service life of the component. Some cracks growing from W-braze interface into the base material have been detected. They are originated by the stresses produced during the cooling stage of the brazing cycle. Regarding the strength of the joints, similar shear strengths of both joints were obtained (˜105 MPa). These values were slightly lower than the ones obtained when pure tungsten was used as the base metal.

[INVITED] Computational intelligence for smart laser materials processing

NASA Astrophysics Data System (ADS)

Casalino, Giuseppe

2018-03-01

Computational intelligence (CI) involves using a computer algorithm to capture hidden knowledge from data and to use them for training ;intelligent machine; to make complex decisions without human intervention. As simulation is becoming more prevalent from design and planning to manufacturing and operations, laser material processing can also benefit from computer generating knowledge through soft computing. This work is a review of the state-of-the-art on the methodology and applications of CI in laser materials processing (LMP), which is nowadays receiving increasing interest from world class manufacturers and 4.0 industry. The focus is on the methods that have been proven effective and robust in solving several problems in welding, cutting, drilling, surface treating and additive manufacturing using the laser beam. After a basic description of the most common computational intelligences employed in manufacturing, four sections, namely, laser joining, machining, surface, and additive covered the most recent applications in the already extensive literature regarding the CI in LMP. Eventually, emerging trends and future challenges were identified and discussed.

25th anniversary article: a decade of organic/polymeric photovoltaic research.

PubMed

Dou, Letian; You, Jingbi; Hong, Ziruo; Xu, Zheng; Li, Gang; Street, Robert A; Yang, Yang

2013-12-10

Organic photovoltaic (OPV) technology has been developed and improved from a fancy concept with less than 1% power conversion efficiency (PCE) to over 10% PCE, particularly through the efforts in the last decade. The significant progress is the result of multidisciplinary research ranging from chemistry, material science, physics, and engineering. These efforts include the design and synthesis of novel compounds, understanding and controlling the film morphology, elucidating the device mechanisms, developing new device architectures, and improving large-scale manufacture. All of these achievements catalyzed the rapid growth of the OPV technology. This review article takes a retrospective look at the research and development of OPV, and focuses on recent advances of solution-processed materials and devices during the last decade, particular the polymer version of the materials and devices. The work in this field is exciting and OPV technology is a promising candidate for future thin film solar cells. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Investigation of Desiccants and CO2 Sorbents for Advanced Exploration Systems 2015-2016

NASA Technical Reports Server (NTRS)

Cmarik, Gregory E.; Knox, Jim

2016-01-01

Advanced Environmental Control and Life Support System (ECLSS) design is critical for human space flight beyond Earth. Current systems enable extended missions in low-Earth orbit, but for deep-space missions, not only will astronauts be outside the reach of resupply operations from Earth but they will also need to handle malfunctions and compensate for the degradation of materials. These two daunting challenges must be overcome for long-term independent space flight. In order to solve the first, separation and reuse of onboard atmosphere components is required. Current systems utilize space vacuum to fully regenerate adsorbent beds, but this is not sustainable thus necessitating a closed-loop system. The second challenge stems from material and performance degradation due to operational cycling and on-board contaminants. This report will review the recent work by the ECLSS team at Marshall Space Flight Center towards overcoming these challenges by characterizing materials via novel methods for use in future systems.

To study the effect of different electrolytes and their concentrations on electrochemical micromachining

NASA Astrophysics Data System (ADS)

Singh, Ramandeep

2018-04-01

The machining of materials on micro-meter and sub-micrometre is considered the technology of future. Due to challenging applications of biomedical and aerospace industries, the traditional manufacturing techniques lacks in dimensional accuracy. Thus for such industries, the technique that can control micron tolerances is Electrochemical Micromachining (EMM). Hard metals and alloys can also be machined by this technique. Thus to develop a novel EMM system setup and to investigate the effect of three different electrolytes i.e NaCl, NaNO3 and HCl with their different concentrations, the current study was conducted. Stainless Steel-304 and copper were chosen as the work piece material in the present study. Taguchi L18 orthogonal array was used for the best combination of experiment. According to the present investigation most prominent factor affecting the material removal (MR) comes out was electrolyte. HCl provides the better MR among other electrolytes i.e. NaNO3 and NaCl. The amount of MR increased with the increase in the concentration of electrolyte.

MSFC Electrostatic Levitator (ESL) Rapid Quench System

NASA Technical Reports Server (NTRS)

SanSoucie, Michael P.; Craven, Paul D.; Rogers, Jan R.

2014-01-01

The NASA Marshall Space Flight Center (MSFC) Electrostatic Levitator (ESL) Laboratory is a unique facility for investigators studying high-temperature materials. The laboratory boasts two levitators in which samples can be levitated, heated, melted, undercooled, and resolidified, all without the interference of a container or data-gathering instrument. The ESL main chamber has been upgraded with the addition of a rapid quench system. This system allows samples to be dropped into a quench vessel that can be filled with a low melting point material, such as a gallium or indium alloy. Thereby allowing rapid quenching of undercooled liquid metals. Up to 8 quench vessels can be loaded into the quench wheel, which is indexed with LabVIEW control software. This allows up to 8 samples to be rapidly quenched before having to open the chamber. The system has been tested successfully on several zirconium samples. Future work will be done with other materials using different quench mediums. Microstructural analysis will also be done on successfully quench samples.

Design of a Protection Thermal Energy Storage Using Phase Change Material Coupled to a Solar Receiver

NASA Astrophysics Data System (ADS)

Verdier, D.; Falcoz, Q.; Ferrière, A.

2014-12-01

Thermal Energy Storage (TES) is the key for a stable electricity production in future Concentrated Solar Power (CSP) plants. This work presents a study on the thermal protection of the central receiver of CSP plant using a tower which is subject to considerable thermal stresses in case of cloudy events. The very high temperatures, 800 °C at design point, impose the use of special materials which are able to resist at high temperature and high mechanical constraints and high level of concentrated solar flux. In this paper we investigate a TES coupling a metallic matrix drilled with tubes of Phase Change Material (PCM) in order to store a large amount of thermal energy and release it in a short time. A numerical model is developed to optimize the arrangement of tubes into the TES. Then a methodology is given, based from the need in terms of thermal capacity, in order to help the choice of the geometry.

Energy Frontier Research Center Materials Science of Actinides (A "Life at the Frontiers of Energy Research" contest entry from the 2011 Energy Frontier Research Centers (EFRCs) Summit and Forum)

ScienceCinema

Burns, Peter (Director, Materials Science of Actinides); MSA Staff

2017-12-09

'Energy Frontier Research Center Materials Science of Actinides' was submitted by the EFRC for Materials Science of Actinides (MSA) to the 'Life at the Frontiers of Energy Research' video contest at the 2011 Science for Our Nation's Energy Future: Energy Frontier Research Centers (EFRCs) Summit and Forum. Twenty-six EFRCs created short videos to highlight their mission and their work. MSA is directed by Peter Burns at the University of Notre Dame, and is a partnership of scientists from ten institutions.The Office of Basic Energy Sciences in the U.S. Department of Energy's Office of Science established the 46 Energy Frontier Research Centers (EFRCs) in 2009. These collaboratively-organized centers conduct fundamental research focused on 'grand challenges' and use-inspired 'basic research needs' recently identified in major strategic planning efforts by the scientific community. The overall purpose is to accelerate scientific progress toward meeting the nation's critical energy challenges.