A shuttle and space station manipulator system for assembly, docking, maintenance, cargo handling and spacecraft retrieval (preliminary design). Volume 2: Concept development and selection

NASA Technical Reports Server (NTRS)

1972-01-01

The overall program background, the various system concepts considered, and the rationale for the selected design are described. The concepts for each subsystem are also described and compared. Details are given for the requirements, boom configuration and dynamics, actuators, man/machine interface and control, visual system, control system, environmental control and life support, data processing, and materials.

Assembling new technologies at the interface of materials science and biology

NASA Astrophysics Data System (ADS)

Stendahl, John C.

Molecular self-assembly can be used to construct advanced materials by taking cues from nature and harnessing noncovalent interactions. This bottom-up approach affords molecular level precision that can cultivate pathways to improved materials function. The graduate research presented in this thesis integrates molecular self-assembly with traditional concepts in chemistry and materials science, with the ultimate goal of developing innovative solutions in technology and medicine. In the field of polymer engineering, self-assembly was used to create supramolecular nanoribbons that, when incorporated into polystyrene, modify its microstructure and significantly enhance its toughness and ductility. In medicine, self-assembly was used to create ordered, chemically functional materials to improve interactions with cells and other constituents of the biological environment. One system that was investigated is based on a triblock molecule in which cholesterol is connected to a lysine dendron by a flexible oligo-(L-lactic acid) spacer. These molecules self-assemble into polar surface coatings on fibrous poly(L-lactic acid) scaffolds that improve the scaffold's wettability and increase its retention of cells during seeding. Another self-assembling system that was investigated for biomedical applications is a family of molecules referred to as peptide amphiphiles (PA's). PA's consist of hydrophobic alkyl tails connected to short, hydrophilic peptides that incorporate biological signaling epitopes. These molecules spontaneously assemble into networks of well-defined nanofibers in aqueous environments, with the signaling epitopes presented in high density on the nanofiber exteriors. Nanofiber assembly is triggered by charge screening on the peptides and is able to produce self-supporting gels in concentrations of less than 1.0 wt.-%. The assembly process and mechanical properties of PA gels was investigated in detail with vibrational spectroscopy and oscillatory rheology. PA nanofibers were used in conjunction with fibrous poly(L-lactic acid] fabrics to create chemically functional scaffolds to facilitate islet cell transplantation. In transplant studies in diabetic mice, the use of scaffolds for islet delivery was shown to significantly improve transplant outcomes over free islet injections. Together, these studies illustrate that molecular self-assembly can be used to create functional materials for a variety of applications. These materials utilize noncovalent interactions to produce supramolecular structures that have important impacts on properties.

Correlation between hierarchical structure of crystal networks and macroscopic performance of mesoscopic soft materials and engineering principles.

PubMed

Lin, Naibo; Liu, Xiang Yang

2015-11-07

This review examines how the concepts and ideas of crystallization can be extended further and applied to the field of mesoscopic soft materials. It concerns the structural characteristics vs. the macroscopic performance, and the formation mechanism of crystal networks. Although this subject can be discussed in a broad sense across the area of mesoscopic soft materials, our main focus is on supramolecular materials, spider and silkworm silks, and biominerals. First, the occurrence of a hierarchical structure, i.e. crystal network and domain network structures, will facilitate the formation kinetics of mesoscopic phases and boost up the macroscopic performance of materials in some cases (i.e. spider silk fibres). Second, the structure and performance of materials can be correlated in some way by the four factors: topology, correlation length, symmetry/ordering, and strength of association of crystal networks. Moreover, four different kinetic paths of crystal network formation are identified, namely, one-step process of assembly, two-step process of assembly, mixed mode of assembly and foreign molecule mediated assembly. Based on the basic mechanisms of crystal nucleation and growth, the formation of crystal networks, such as crystallographic mismatch (or noncrystallographic) branching (tip branching and fibre side branching) and fibre/polymeric side merging, are reviewed. This facilitates the rational design and construction of crystal networks in supramolecular materials. In this context, the (re-)construction of a hierarchical crystal network structure can be implemented by thermal, precipitate, chemical, and sonication stimuli. As another important class of soft materials, the unusual mechanical performance of spider and silkworm silk fibres are reviewed in comparison with the regenerated silk protein derivatives. It follows that the considerably larger breaking stress and unusual breaking strain of spider silk fibres vs. silkworm silk fibres can be interpreted according to the synergistically correlated hierarchical structures of the domain and crystal networks, which can be quantified by the hierarchical structural correlation and the four structural parameters. Based on the concept of crystal networks, the new understanding acquired will transfer the research and engineering of mesoscopic materials, particularly, soft functional materials, to a new phase.

Large-scale self-assembled zirconium phosphate smectic layers via a simple spray-coating process

NASA Astrophysics Data System (ADS)

Wong, Minhao; Ishige, Ryohei; White, Kevin L.; Li, Peng; Kim, Daehak; Krishnamoorti, Ramanan; Gunther, Robert; Higuchi, Takeshi; Jinnai, Hiroshi; Takahara, Atsushi; Nishimura, Riichi; Sue, Hung-Jue

2014-04-01

The large-scale assembly of asymmetric colloidal particles is used in creating high-performance fibres. A similar concept is extended to the manufacturing of thin films of self-assembled two-dimensional crystal-type materials with enhanced and tunable properties. Here we present a spray-coating method to manufacture thin, flexible and transparent epoxy films containing zirconium phosphate nanoplatelets self-assembled into a lamellar arrangement aligned parallel to the substrate. The self-assembled mesophase of zirconium phosphate nanoplatelets is stabilized by epoxy pre-polymer and exhibits rheology favourable towards large-scale manufacturing. The thermally cured film forms a mechanically robust coating and shows excellent gas barrier properties at both low- and high humidity levels as a result of the highly aligned and overlapping arrangement of nanoplatelets. This work shows that the large-scale ordering of high aspect ratio nanoplatelets is easier to achieve than previously thought and may have implications in the technological applications for similar materials.

Proceedings of the conference on energy conservation: Retrofit of Municipal Wastewater Treatment Facilities

NASA Astrophysics Data System (ADS)

1982-02-01

The concepts of the roles of heat and temperature, ventilation and water removal when organic material is assembled into a self insulating mass are summarized. The practical application of these concepts in static pile configuration or the Rutgers process are outlined. The concepts and means of application are relevant to all design approaches whether or not a reactor structure is involved, whether the process is batch or continuous, and whether the mass is agitated or static.

Validated Feasibility Study of Integrally Stiffened Metallic Fuselage Panels for Reducing Manufacturing Costs: Cost Assessment of Manufacturing/Design Concepts

NASA Technical Reports Server (NTRS)

Metschan, S.

2000-01-01

The objective of the Integral Airframe Structures (IAS) program was to demonstrate, for an integrally stiffened structural concept, performance and weight equal to "built-up" structure with lower manufacturing cost. This report presents results of the cost assessment for several design configuration/manufacturing method combinations. The attributes of various cost analysis models were evaluated and COSTRAN selected for this study. A process/design cost evaluation matrix was developed based on material, forming, machining, and assembly of structural sub-elements and assembled structure. A hybrid design, made from high-speed machined extruded frames that are mechanically fastened to high-speed machined plate skin/stringer panels, was identified as the most cost-effective manufacturing solution. Recurring labor and material costs of the hybrid design are up to 61 percent less than the current built-up technology baseline. This would correspond to a total cost reduction of $1.7 million per ship set for a 777-sized airplane. However, there are important outstanding issues with regard to the cost of capacity of high technology machinery, and the ability to cost-effectively provide surface finish acceptable to the commercial aircraft industry. The projected high raw material cost of large extrusions also played an important role in the trade-off between plate and extruded concepts.

Reuse of assembly systems: a great ecological and economical potential for facility suppliers

NASA Astrophysics Data System (ADS)

Weule, Hartmut; Buchholz, Carsten

2001-02-01

In addition to the consumer goods, capital goods offer a great potential for ecological and economic optimization. In view of this fact the project WiMonDi (Re-Use of Assembly Systems as new Business Fields), started in September 1998, focuses a marketable Remanufacturing and Re-Use of modules and components of assembly systems by using technically and organizationally continuous concepts. The objective of the closed Facility-Management-System is to prolong the serviceable lifespan of assembly facilities through the organized dismantling, refurbishment and reconditioning of the assembly facilities as well as their components. Therefore, it is necessary to develop easible and methodical strategies to realize a workable Re-Use concept. Within the project the focus is based on the optimization of Re-Use-strategies - the direct Re-Use, the Re-Use including Refurbishment as well as Material Recycling. The decision for an optimal strategy depends on economical (e.g. residual value, cost/benefit of relevant processes, etc.), ecological (e.g. pollutant components /substances), etc.) and technical parameters (e.g. reliability, etc.). For the purpose to integrate the total cost-of-ownership of products or components, WiMonDi integrates the costs of the use of products as well as the Re-Use costs/benefits. To initiate the conception of new distribution and user models between the supplier and the user of assembly facilities the described approach is conducted in close cooperation between Industry and University.

Supplying of Assembly Lines Using Train of Trucks

NASA Astrophysics Data System (ADS)

Čujan, Zdeněk; Fedorko, Gabriel

2016-11-01

The typical supply system conceptions, i.e. the concepts "Just-in-time" (JIT) and "Just-in-sequence" (JIS) are very important factors with regard to a fluent operation of the assembly lines. Therefore the contemporary intra plant transport systems are being replaced by a new kind of the transportation technology, namely by means of the trains of trucks. The trains of trucks are used in two possible operational modes: either with a driver or without driver (fully automated). The trucks of the logistic trains are also cheaper and they are able to carry a larger volume and mass of the material at once. There are reduced in this way not only the investment costs, but also the operational expenses.

Assembly and testing of microparticle and microcapsule smart tattoo materials

NASA Astrophysics Data System (ADS)

McShane, Michael J.

2007-01-01

Microscale biochemical sensors are attractive for in vitro diagnostics and disease management, as well as medical and biological research applications. Fluorescent sensors, coupling specific glucose-binding proteins with fluorescent readout methods, have been developed for this purpose. Our work has focused on the development of assembly and packaging systems for producing micro- and nanoscale sensing components that can be used as implants, intracellular reporters, or as elements in larger systems. Both hybrid organic/inorganic particles and hollow microshells have been developed to physically couple the sensing materials together in biocompatible, semipermeable packages. Fabrication details and sensor characterization are used to demonstrate the potential of these sensor concepts.

DNA-nanoparticle superlattices formed from anisotropic building blocks

NASA Astrophysics Data System (ADS)

Jones, Matthew R.; Macfarlane, Robert J.; Lee, Byeongdu; Zhang, Jian; Young, Kaylie L.; Senesi, Andrew J.; Mirkin, Chad A.

2010-11-01

Directional bonding interactions in solid-state atomic lattices dictate the unique symmetries of atomic crystals, resulting in a diverse and complex assortment of three-dimensional structures that exhibit a wide variety of material properties. Methods to create analogous nanoparticle superlattices are beginning to be realized, but the concept of anisotropy is still largely underdeveloped in most particle assembly schemes. Some examples provide interesting methods to take advantage of anisotropic effects, but most are able to make only small clusters or lattices that are limited in crystallinity and especially in lattice parameter programmability. Anisotropic nanoparticles can be used to impart directional bonding interactions on the nanoscale, both through face-selective functionalization of the particle with recognition elements to introduce the concept of valency, and through anisotropic interactions resulting from particle shape. In this work, we examine the concept of inherent shape-directed crystallization in the context of DNA-mediated nanoparticle assembly. Importantly, we show how the anisotropy of these particles can be used to synthesize one-, two- and three-dimensional structures that cannot be made through the assembly of spherical particles.

Self-assembly strategies for the synthesis of functional nanostructured materials

NASA Astrophysics Data System (ADS)

Perego, M.; Seguini, G.

2016-06-01

Self-assembly is the autonomous organization of components into patterns or structures without human intervention. This is the approach followed by nature to generate living cells and represents one of the practical strategies to fabricate ensembles of nanostructures. In static self-assembly the formation of ordered structures could require energy but once formed the structures are stable. The introduction of additional regular features in the environment could be used to template the self-assembly guiding the organization of the components and determining the final structure they form. In this regard self-assembly of block copolymers represents a potent platform for fundamental studies at the nanoscale and for application-driven investigation as a tool to fabricate functional nanostructured materials. Block copolymers can hierarchically assemble into chemically distinct domains with size and periodicity on the order of 10nm or below, offering a potentially inexpensive route to generate large-area nanostructured materials. The final structure characteristics of these materials are dictated by the properties of the elementary block copolymers, like chain length, volume fraction or degree of block incompatibility. Modern synthetic chemistry offers the possibility to design these macromolecules with very specific length scales and geometries, directly embodying in the block copolymers the code that drives their self- assembling process. The understanding of the kinetics and thermodynamics of the block copolymer self-assembly process in the bulk phase as well as in thin films represents a fundamental prerequisite toward the exploitation of these materials. Incorporating block copolymer into device fabrication procedures or directly into devices, as active elements, will lead to the development of a new generation of devices fabricated using the fundamental law of nature to our advantage in order to minimize cost and power consumption in the fabrication process. Moreover the capability to precisely organize these nano-objects on appropriate substrates is the key point to support the technological development of new device concepts with predictable characteristics based on these nano-materials. In the next coming years this area of research, at the intersection between fundamental science and technology, is expected to disclose additional insights in the physics of the self-assembly process and to delineate unforeseen applications for these exciting materials.

Viper cabin-fuselage structural design concept with engine installation and wing structural design

NASA Technical Reports Server (NTRS)

Marchesseault, B.; Carr, D.; Mccorkle, T.; Stevens, C.; Turner, D.

1993-01-01

This report describes the process and considerations in designing the cabin, nose, drive shaft, and wing assemblies for the 'Viper' concept aircraft. Interfaces of these assemblies, as well as interfaces with the sections of the aircraft aft of the cabin, are also discussed. The results of the design process are included. The goal of this project is to provide a structural design which complies with FAR 23 requirements regarding occupant safety, emergency landing loads, and maneuvering loads. The design must also address the interfaces of the various systems in the cabin, nose, and wing, including the drive shaft, venting, vacuum, electrical, fuel, and control systems. Interfaces between the cabin assembly and the wing carrythrough and empennage assemblies were required, as well. In the design of the wing assemblies, consistency with the existing cabin design was required. The major areas considered in this report are materials and construction, loading, maintenance, environmental considerations, wing assembly fatigue, and weight. The first three areas are developed separately for the nose, cabin, drive shaft, and wing assemblies, while the last three are discussed for the entire design. For each assembly, loading calculations were performed to determine the proper sizing of major load carrying components. Table 1.0 lists the resulting margins of safety for these key components, along with the types of the loads involved, and the page number upon which they are discussed.

Method for Producing Launch/Landing Pads and Structures Project

NASA Technical Reports Server (NTRS)

Mueller, Robert P. (Compiler)

2015-01-01

Current plans for deep space exploration include building landing-launch pads capable of withstanding the rocket blast of much larger spacecraft that that of the Apollo days. The proposed concept will develop lightweight launch and landing pad materials from in-situ materials, utilizing regolith to produce controllable porous cast metallic foam brickstiles shapes. These shapes can be utilized to lay a landing launch platform, as a construction material or as more complex parts of mechanical assemblies.

Large space structures and systems in the space station era: A bibliography with indexes (supplement 05)

NASA Technical Reports Server (NTRS)

1993-01-01

Bibliographies and abstracts are listed for 1363 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1991 and July 31, 1992. Topics covered include technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion and solar power satellite systems.

Large space structures and systems in the space station era: A bibliography with indexes (supplement 05)

NASA Astrophysics Data System (ADS)

1993-03-01

Bibliographies and abstracts are listed for 1363 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1991 and July 31, 1992. Topics covered include technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion and solar power satellite systems.

Waveguide metatronics: Lumped circuitry based on structural dispersion.

PubMed

Li, Yue; Liberal, Iñigo; Della Giovampaola, Cristian; Engheta, Nader

2016-06-01

Engineering optical nanocircuits by exploiting modularization concepts and methods inherited from electronics may lead to multiple innovations in optical information processing at the nanoscale. We introduce the concept of "waveguide metatronics," an advanced form of optical metatronics that uses structural dispersion in waveguides to obtain the materials and structures required to construct this class of circuitry. Using numerical simulations, we demonstrate that the design of a metatronic circuit can be carried out by using a waveguide filled with materials with positive permittivity. This includes the implementation of all "lumped" circuit elements and their assembly in a single circuit board. In doing so, we extend the concepts of optical metatronics to frequency ranges where there are no natural plasmonic materials available. The proposed methodology could be exploited as a platform to experimentally validate optical metatronic circuits in other frequency regimes, such as microwave frequency setups, and/or to provide a new route to design optical nanocircuitry.

Using Sorting by Reversal: Breakpoint Graph for Gene Assembly in Ciliates

NASA Astrophysics Data System (ADS)

Brijder, Robert; Jan Hoogeboom, Hendrik

2007-09-01

The theory of gene assembly in ciliates has much in common with the theory of sorting by reversal. Both model processes that are based on splicing, and have a fixed begin and end product. The main difference is the type of splicing operations used to obtain the end product from the begin product. In this overview paper we show that the concept of breakpoint graph, known from the theory of sorting by reversal, has many uses in the theory of gene assembly. Our aim is to present the material in an intuitive and informal manner to allow for an efficient introduction into the subject.

Design fabrication and nondestructive testing of six experimental AGCarb/Intermold 3 cylinder assemblies

NASA Technical Reports Server (NTRS)

Thacher, E. F.

1972-01-01

Six subscale Intermold cylinder assemblies with a total of twelve different concepts for transition to AGCarb were fabricated. Three of the cylinder assemblies were made by helically winding the hoop fibers and three were of orthogonal configuration. The fabrication process is summarized and details of each manufacturing method are given. The objectives of the test program were to: (1) demonstrate the fabricability of the Intermold 3 subscale flanges, (2) produce an integral transition from Intermold 3 to AGCarb material, (3) define a workable manufacturing process, and (4) identify a best suited inspection method. The objectives were met and the results are described.

Nanoarchitectonics from Molecular Units to Living-Creature-Like Motifs.

PubMed

Ariga, Katsuhiko; Mori, Taizo; Shrestha, Lok Kumar

2017-12-04

Important points for the fabrication of functional materials are the creation of nanoscale/molecular-scale units and architecting them into functional materials and systems. Recently, a new conceptual paradigm, nanoarchitectonics, has been proposed to combine nanotechnology and other methodologies including supramolecular chemistry, self-assembly and self-organization to satisfy major features of nanoscience and promote the creation of functional materials and systems. In this account article, our recent research results in materials development based on the nanoarchitectonics concept are summarized in two stories, (i) nanoarchitectonics from fullerenes as the simplest nano-units and (ii) dimension-dependent nanoarchitectonics from various structural units. The former demonstrates creativity of the nanoarchitectonics concept only with simple construction stuffs on materials fabrications, and a wide range of material applicability for the nanoarchitectonics strategy is realized in the latter ones. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Materials Challenges in Space Exploration

NASA Technical Reports Server (NTRS)

Bhat, Biliyar N.

2005-01-01

United States civil space program administered by National Aeronautics and Space Administration has a new strategic direction to explore the solar system. This new 'vision for space exploration' encompasses a broad range of human and robotic missions, including the Moon. Mars and destinations beyond. These missions require advanced systems and capabilities that will accelerate the development of many critical technologies, including advanced materials and structural concepts. Specifically, it is planned to develop high-performance materials for vehicle structures, propulsion systems, and space suits; structural concepts for modular assembly for space infrastructure: lightweight deployable and inflatable structures for large space systems and crew habitats; and highly integrated structural systems and advanced thermal management systems for reducing launch mass and volume. This paper will present several materials challenges in advanced space systems-high performance structural and thermal materials, space durable materials, radiation protection materials, and nano-structural materials. Finally, the paper will take a look at the possibility of utilizing materials in situ, i.e., processing materials on the surface of the Moon and Mars.

Shape-shifting colloids via stimulated dewetting

PubMed Central

Youssef, Mena; Hueckel, Theodore; Yi, Gi-Ra; Sacanna, Stefano

2016-01-01

The ability to reconfigure elementary building blocks from one structure to another is key to many biological systems. Bringing the intrinsic adaptability of biological systems to traditional synthetic materials is currently one of the biggest scientific challenges in material engineering. Here we introduce a new design concept for the experimental realization of self-assembling systems with built-in shape-shifting elements. We demonstrate that dewetting forces between an oil phase and solid colloidal substrates can be exploited to engineer shape-shifting particles whose geometry can be changed on demand by a chemical or optical signal. We find this approach to be quite general and applicable to a broad spectrum of materials, including polymers, semiconductors and magnetic materials. This synthetic methodology can be further adopted as a new experimental platform for designing and rapidly prototyping functional colloids, such as reconfigurable micro swimmers, colloidal surfactants and switchable building blocks for self-assembly. PMID:27426418

Shape-shifting colloids via stimulated dewetting

NASA Astrophysics Data System (ADS)

Youssef, Mena; Hueckel, Theodore; Yi, Gi-Ra; Sacanna, Stefano

2016-07-01

The ability to reconfigure elementary building blocks from one structure to another is key to many biological systems. Bringing the intrinsic adaptability of biological systems to traditional synthetic materials is currently one of the biggest scientific challenges in material engineering. Here we introduce a new design concept for the experimental realization of self-assembling systems with built-in shape-shifting elements. We demonstrate that dewetting forces between an oil phase and solid colloidal substrates can be exploited to engineer shape-shifting particles whose geometry can be changed on demand by a chemical or optical signal. We find this approach to be quite general and applicable to a broad spectrum of materials, including polymers, semiconductors and magnetic materials. This synthetic methodology can be further adopted as a new experimental platform for designing and rapidly prototyping functional colloids, such as reconfigurable micro swimmers, colloidal surfactants and switchable building blocks for self-assembly.

Technology for large space systems: A bibliography with indexes (supplement 08)

NASA Technical Reports Server (NTRS)

1983-01-01

This bibliography lists 414 reports, articles and other documents introduced into the NASA scientific and technical information system. It provides helpful information to the researcher, manager, and designer in technology development and mission design in the area of Large Space System Technology. Subject matter is grouped according to systems, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems.

Technology for large space systems: A bibliography with indexes (supplement 09)

NASA Technical Reports Server (NTRS)

1983-01-01

This bibliography lists 414 reports, articles and other documents introduced into the NASA scientific and technical information system between January 1, 1983 and June 30, 1983. Information on technology development and mission design in the area of Large Space System Technology is provided. Subject matter is grouped according to systems, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics. advanced materials, assembly concepts, propulsion, and solar power satellite systems.

Technology for large space systems: A bibliography with indexes (supplement 19)

NASA Technical Reports Server (NTRS)

1988-01-01

This bibliography lists 526 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1988 and June 30, 1988. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems.

Large space structures and systems in the space station era: A bibliography with indexes (supplement 04)

NASA Astrophysics Data System (ADS)

1992-10-01

Bibliographies and abstracts are listed for 1211 reports, articles, and other documents introduced into the NASA scientific and technical information system between 1 Jul. and 30 Dec. 1991. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems.

Technology for large space systems: A bibliography with indexes (supplement 14)

NASA Technical Reports Server (NTRS)

1986-01-01

This bibliography lists 645 reports, articles and other documents introduced into the NASA scientific and technical information system between July 1, 1985 and December 31, 1985. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems.

Large space structures and systems in the space station era: A bibliography with indexes (supplement 04)

NASA Technical Reports Server (NTRS)

1992-01-01

Bibliographies and abstracts are listed for 1211 reports, articles, and other documents introduced into the NASA scientific and technical information system between 1 Jul. and 30 Dec. 1991. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems.

Technology for large space systems: A bibliography with indexes (supplement 11)

NASA Technical Reports Server (NTRS)

1985-01-01

This bibliography contains 539 abstracts of reports, articles and other documents introduced into the NASA scientific and technical information system between January 1, 1984 and December 31, 1984. Abstracts are arranged in the following categories: systems; analysis and design techniques; structural concepts; structural and thermal analysis; structural dynamics and control; electronics; advanced materials; assembly concepts; propulsion; and miscellaneous. Subject, personal author, corporate source, contract number, report number, and accession number indexes are listed.

Technology for large space systems: A bibliography with indexes (supplement 17)

NASA Technical Reports Server (NTRS)

1987-01-01

This bibliography lists 512 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1987 and June 30, 1987. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems.

Technology for large space systems: A bibliography with indexes (supplement 10)

NASA Technical Reports Server (NTRS)

1984-01-01

The bibliography lists 408 reports, articles and other documents introduced into the NASA scientific and technical information system to provide helpful information to the researcher, manager, and designer in technology development and mission design in the area of large space system technology. Subject matter is grouped according to systems, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems.

Technology for large space systems: A bibliography with indexes (supplement 13)

NASA Technical Reports Server (NTRS)

1986-01-01

This bibliography lists 399 reports, articles and other documents introduced into the NASA scientific and technical information system between January 1, 1985 and June 30, 1985. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems.

Technology for large space systems: A bibliography with indexes (supplement 18)

NASA Technical Reports Server (NTRS)

1988-01-01

This bibliography lists 569 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 1,1987 and December 31, 1987. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems.

Technology for large space systems: A bibliography with indexes (supplement 16)

NASA Technical Reports Server (NTRS)

1987-01-01

This bibliography lists 673 reports, articles and other documents introduced into the NASA scientific and technical information system between July 1, 1986 and December 31, 1986. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems.

Technology for Large Space Systems: a Bibliography with Indexes (Supplement 21)

NASA Technical Reports Server (NTRS)

1988-01-01

This bibliography lists 745 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1989 and June 30, 1989. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems.

Technology for large space systems: A bibliography with indexes (supplement 15)

NASA Technical Reports Server (NTRS)

1987-01-01

This bibliography lists 594 reports, articles and other documents introduced into the NASA scientific and technical information system between January 1, 1986 and June 30, 1986. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems.

A space crane concept for performing on-orbit assembly

NASA Technical Reports Server (NTRS)

Dorsey, John T.

1992-01-01

The topics are presented in viewgraph form and include: in-space assembly and construction enhances future mission planning flexibility; in-space assembly and construction facility concept; space crane concept with mobile base; fundamental characteristics; space crane research approach; spacecraft component positioning and assembly test-bed; and articulating joint testbed.

Printing, folding and assembly methods for forming 3D mesostructures in advanced materials

NASA Astrophysics Data System (ADS)

Zhang, Yihui; Zhang, Fan; Yan, Zheng; Ma, Qiang; Li, Xiuling; Huang, Yonggang; Rogers, John A.

2017-03-01

A rapidly expanding area of research in materials science involves the development of routes to complex 3D structures with feature sizes in the mesoscopic range (that is, between tens of nanometres and hundreds of micrometres). A goal is to establish methods for controlling the properties of materials systems and the function of devices constructed with them, not only through chemistry and morphology, but also through 3D architectures. The resulting systems, sometimes referred to as metamaterials, offer engineered behaviours with optical, thermal, acoustic, mechanical and electronic properties that do not occur in the natural world. Impressive advances in 3D printing techniques represent some of the most broadly recognized developments in this field, but recent successes with strategies based on concepts in origami, kirigami and deterministic assembly provide additional, unique options in 3D design and high-performance materials. In this Review, we highlight the latest progress and trends in methods for fabricating 3D mesostructures, beginning with the development of advanced material inks for nozzle-based approaches to 3D printing and new schemes for 3D optical patterning. In subsequent sections, we summarize more recent methods based on folding, rolling and mechanical assembly, including their application with materials such as designer hydrogels, monocrystalline inorganic semiconductors and graphene.

In situ 3D nanoprinting of free-form coupling elements for hybrid photonic integration

NASA Astrophysics Data System (ADS)

Dietrich, P.-I.; Blaicher, M.; Reuter, I.; Billah, M.; Hoose, T.; Hofmann, A.; Caer, C.; Dangel, R.; Offrein, B.; Troppenz, U.; Moehrle, M.; Freude, W.; Koos, C.

2018-04-01

Hybrid photonic integration combines complementary advantages of different material platforms, offering superior performance and flexibility compared with monolithic approaches. This applies in particular to multi-chip concepts, where components can be individually optimized and tested. The assembly of such systems, however, requires expensive high-precision alignment and adaptation of optical mode profiles. We show that these challenges can be overcome by in situ printing of facet-attached beam-shaping elements. Our approach allows precise adaptation of vastly dissimilar mode profiles and permits alignment tolerances compatible with cost-efficient passive assembly techniques. We demonstrate a selection of beam-shaping elements at chip and fibre facets, achieving coupling efficiencies of up to 88% between edge-emitting lasers and single-mode fibres. We also realize printed free-form mirrors that simultaneously adapt beam shape and propagation direction, and we explore multi-lens systems for beam expansion. The concept paves the way to automated assembly of photonic multi-chip systems with unprecedented performance and versatility.

Hybrid Gama Emission Tomography (HGET): FY16 Annual Report

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

Miller, Erin A.; Smith, Leon E.; Wittman, Richard S.

2017-02-01

Current International Atomic Energy Agency (IAEA) methodologies for the verification of fresh low-enriched uranium (LEU) and mixed oxide (MOX) fuel assemblies are volume-averaging methods that lack sensitivity to individual pins. Further, as fresh fuel assemblies become more and more complex (e.g., heavy gadolinium loading, high degrees of axial and radial variation in fissile concentration), the accuracy of current IAEA instruments degrades and measurement time increases. Particularly in light of the fact that no special tooling is required to remove individual pins from modern fuel assemblies, the IAEA needs new capabilities for the verification of unirradiated (i.e., fresh LEU and MOX)more » assemblies to ensure that fissile material has not been diverted. Passive gamma emission tomography has demonstrated potential to provide pin-level verification of spent fuel, but gamma-ray emission rates from unirradiated fuel emissions are significantly lower, precluding purely passive tomography methods. The work presented here introduces the concept of Hybrid Gamma Emission Tomography (HGET) for verification of unirradiated fuels, in which a neutron source is used to actively interrogate the fuel assembly and the resulting gamma-ray emissions are imaged using tomographic methods to provide pin-level verification of fissile material concentration.« less

Design of a mercury Propellant Storage and Distribution assembly

NASA Technical Reports Server (NTRS)

Holcomb, L. B.; Womack, J. R.

1973-01-01

A study has been conducted of a Propellant Storage and Distribution (PSD) assembly for a solar electric propulsion (SEP) thrust subsystem. As a result of the trade-off study an elastomeric diaphragm propellant tank with nitrogen blowdown pressurization was the method selected for propellant expulsion. This study included the following propellant management devices: surface tension, metallic bellows, and metallic and elastomeric diaphragms. Pressurant supply concepts investigated were blowdown, externally pressure regulated, vaporizing Freon 113, and heated CO2/Zeolite. The configuration selected consists of a single propellant tank, a single main propellant latching-solenoid valve, and individual thruster latching-solenoid valves. Stainless steel was the selected tankage material and AF-E-332 was the selected diaphragm material. The PSD design characteristics and interfaces are summarized.

Preliminary design approach for large high precision segmented reflectors

NASA Technical Reports Server (NTRS)

Mikulas, Martin M., Jr.; Collins, Timothy J.; Hedgepeth, John M.

1990-01-01

A simplified preliminary design capability for erectable precision segmented reflectors is presented. This design capability permits a rapid assessment of a wide range of reflector parameters as well as new structural concepts and materials. The preliminary design approach was applied to a range of precision reflectors from 10 meters to 100 meters in diameter while considering standard design drivers. The design drivers considered were: weight, fundamental frequency, launch packaging volume, part count, and on-orbit assembly time. For the range of parameters considered, on-orbit assembly time was identified as the major design driver. A family of modular panels is introduced which can significantly reduce the number of reflector parts and the on-orbit assembly time.

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.

Technology for large space systems: A special bibliography with indexes

NASA Technical Reports Server (NTRS)

1979-01-01

This bibliography lists 460 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1968 and December 31, 1978. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design in the area of the Large Space Systems Technology (LSST) Program. Subject matter is grouped according to systems, interactive analysis and design, structural concepts, control systems, electronics, advanced materials, assembly concepts, propulsion, and flight experiments.

Technology for large space systems: A special bibliography with indexes (supplement 01)

NASA Technical Reports Server (NTRS)

1979-01-01

This bibliography lists 180 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1979 and June 30, 1979. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design in the area of the Large Space Systems Technology (LSST) Program. Subject matter is grouped according to systems, interactive analysis and design, structural concepts, control systems, electronics, advanced materials, assembly concepts, propulsion, and flight experiments.

Large space structures and systems in the space station era: A bibliography with indexes

NASA Technical Reports Server (NTRS)

Ferrainolo, John J. (Compiler); Lawrence, George F. (Compiler)

1991-01-01

Bibliographies and abstracts are listed for 1219 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 1, 1990 and December 31, 1990. The purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems.

Large space structures and systems in the space station era: A bibliography with indexes

NASA Technical Reports Server (NTRS)

Ferrainolo, John J. (Editor)

1990-01-01

Bibliographies and abstracts are listed for 1372 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1990 and June 30, 1990. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems.

Technology for large space systems: A special bibliography with indexes (supplement 04)

NASA Technical Reports Server (NTRS)

1981-01-01

This bibliography lists 259 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 1, 1980 and December 31, 1980. Its purpose is to provide information to the researcher, manager, and designer in technology development and mission design in the area of the Large Space Systems Technology Program. Subject matter is grouped according to systems, interactive analysis and design. Structural concepts, control systems, electronics, advanced materials, assembly concepts, propulsion, solar power satellite systems, and flight experiments.

Programmable Assembly of Hybrid Nanoclusters.

PubMed

Ni, Songbo; Wolf, Heiko; Isa, Lucio

2018-02-20

Hybrid nanoparticle clusters (often metallic) are interesting plasmonic materials with tunable resonances and a near-field electromagnetic enhancement at interparticle junctions. Therefore, in recent years, we have witnessed a surge in both the interest in these materials and the efforts to obtain them. However, a versatile fabrication of hybrid nanoclusters, that is, combining more than one material, still remains an open challenge. Current lithographical or self-assembly methods are limited to the preparation of hybrid clusters with up to two different materials and typically to the fabrication of hybrid dimers. Here, we provide a novel strategy to deposit and align not only hybrid dimers but also hybrid nanoclusters possessing more complex shapes and compositions. Our strategy is based on the downscaling of sequential capillarity-assisted particle assembly over topographical templates. As a proof of concept, we demonstrate dimers, linear trimers, and 2D nanoclusters with programmable compositions from a range of metallic nanoparticles. Our process does not rely on any specific chemistry and can be extended to a large variety of particles and shapes. The template also simultaneously aligns the hybrid (often anisotropic) nanoclusters, which could facilitate device integration, for example, for optical readout after transfer to other substrates by a printing step. We envisage that this new fabrication route will enable the assembly and positioning of complex hybrid nanoclusters of different functional nanoparticles to study coupling effects not only locally but also at larger scales for new nanoscale optical devices.

Self-assembly of discrete metal complexes in aqueous solution via block copolypeptide amphiphiles.

PubMed

Kuroiwa, Keita; Masaki, Yoshitaka; Koga, Yuko; Deming, Timothy J

2013-01-21

The integration of discrete metal complexes has been attracting significant interest due to the potential of these materials for soft metal-metal interactions and supramolecular assembly. Additionally, block copolypeptide amphiphiles have been investigated concerning their capacity for self-assembly into structures such as nanoparticles, nanosheets and nanofibers. In this study, we combined these two concepts by investigating the self-assembly of discrete metal complexes in aqueous solution using block copolypeptides. Normally, discrete metal complexes such as [Au(CN)(2)]-, when molecularly dispersed in water, cannot interact with one another. Our results demonstrated, however, that the addition of block copolypeptide amphiphiles such as K(183)L(19) to [Au(CN)(2)]- solutions induced one-dimensional integration of the discrete metal complex, resulting in photoluminescence originating from multinuclear complexes with metal-metal interactions. Transmission electron microscopy (TEM) showed a fibrous nanostructure with lengths and widths of approximately 100 and 20 nm, respectively, which grew to form advanced nanoarchitectures, including those resembling the weave patterns of Waraji (traditional Japanese straw sandals). This concept of combining block copolypeptide amphiphiles with discrete coordination compounds allows the design of flexible and functional supramolecular coordination systems in water.

Soft 2D nanoarchitectonics

NASA Astrophysics Data System (ADS)

Ariga, Katsuhiko; Watanabe, Shun; Mori, Taizo; Takeya, Jun

2018-04-01

Nanoarchitectonics is a new paradigm to combine and unify nanotechnology with other sciences and technologies, such as supramolecular chemistry, self-assembly, self-organization, materials technology for manipulation of the size of material objects, and even biotechnology for hybridization with bio-components. The nanoarchitectonic concept leads to the synergistic combination of various methodologies in materials production, including atomic/molecular-level control, self-organization, and field-controlled organization. The focus of this review is on soft 2D nanoarchitectonics. Scientific views on soft 2D nanomaterials are not fully established compared with those on rigid 2D materials. Here, we collect recent examples of 2D nanoarchitectonic constructions of functional materials and systems with soft components. These examples are selected according to the following three categories on the basis of 2D spatial density and motional freedom: (i) well-packed and oriented organic 2D materials with rational design of component molecules and device applications, (ii) well-defined assemblies with 2D porous structures as 2D network materials, and (iii) 2D control of molecular machines and receptors on the basis of certain motional freedom confined in two dimensions.

The ROM Kit: A Fresh Look at Teaching Roman History.

ERIC Educational Resources Information Center

Shore, Paul J.

1982-01-01

Describes materials in a kit assembled by the Royal Ontario Museum (ROM) that can be used to revitalize the teaching of Roman history and as a model for teaching about ancient history in general. The author also suggests a new approach, concepts, and topics that should be used in teaching Roman history. (AM)

Ionic self-assembly for functional hierarchical nanostructured materials.

PubMed

Faul, Charl F J

2014-12-16

CONSPECTUS: The challenge of constructing soft functional materials over multiple length scales can be addressed by a number of different routes based on the principles of self-assembly, with the judicious use of various noncovalent interactions providing the tools to control such self-assembly processes. It is within the context of this challenge that we have extensively explored the use of an important approach for materials construction over the past decade: exploiting electrostatic interactions in our ionic self-assembly (ISA) method. In this approach, cooperative assembly of carefully chosen charged surfactants and oppositely charged building blocks (or tectons) provides a facile noncovalent route for the rational design and production of functional nanostructured materials. Generally, our research efforts have developed with an initial focus on establishing rules for the construction of novel noncovalent liquid-crystalline (LC) materials. We found that the use of double-tailed surfactant species (especially branched double-tailed surfactants) led to the facile formation of thermotropic (and, in certain cases, lyotropic) phases, as demonstrated by extensive temperature-dependent X-ray and light microscopy investigations. From this core area of activity, research expanded to cover issues beyond simple construction of anisotropic materials, turning to the challenge of inclusion and exploitation of switchable functionality. The use of photoactive azobenzene-containing ISA materials afforded opportunities to exploit both photo-orientation and surface relief grating formation. The preparation of these anisotropic LC materials was of interest, as the aim was the facile production of disposable and low-cost optical components for display applications and data storage. However, the prohibitive cost of the photo-orientation processes hampered further exploitation of these materials. We also expanded our activities to explore ISA of biologically relevant tectons, specifically deoxyguanosine monophosphate. This approach proved, in combination with block copolymer (BCP) self-assembly, very fruitful for the construction of complex and hierarchical functional materials across multiple length scales. Molecular frustration and incommensurability, which played a major role in structure formation in combination with nucleotide assembly, have now become important tools to tune supramolecular structure formation. These concepts, that is, the use of BCP assembly and incommensurability, in combination with metal-containing polymeric materials, have provided access to novel supramolecular morphologies and, more importantly, design rules to prepare such constructs. These design rules are now also being applied to the assembly of electroactive oligo(aniline)-based materials for the preparation of highly ordered functional soft materials, and present an opportunity for materials development for applications in energy storage. In this Account, we therefore discuss investigations into (i) the inclusion and preparation of supramolecular photoactive and electroactive materials; (ii) the exploitation and control over multiple noncovalent interactions to fine-tune function, internal structure, and long-range order and (iii) exploration of construction over multiple length scales by combination of ISA with well-known BCP self-assembly. Combination of ISA with tuning of volume fractions, mutual compatibility, and molecular frustration now provides a versatile tool kit to construct complex and hierarchical functional materials in a facile noncovalent way. A direct challenge for future ISA activities would certainly be the construction of functional mesoscale objects. However, within a broader scientific context, the challenge would be to exploit this powerful assembly tool for application in areas of research with societal impact, for example, energy storage and generation. The hope is that this Account will provide a platform for such future research activities and opportunities.

Mars habitat

NASA Technical Reports Server (NTRS)

Ayers, Dale; Barnes, Timothy; Bryant, Woody; Chowdhury, Parveen; Dillard, Joe; Gardner, Vernadette; Gregory, George; Harmon, Cheryl; Harrell, Brock; Hilton, Sherrill

1991-01-01

The objective of this study is to develop a conceptual design for a permanently manned, self-sustaining Martian facility, to accommodate a crew of 20 people. The goal is to incorporate the major functions required for long term habitation in the isolation of a barren planet into a thriving ecosystem. These functions include living, working, service, and medical facilities as well as a green house. The main design task was to focus on the internal layout while investigating the appropriate structure, materials, and construction techniques. The general concept was to create a comfortable, safe living environment for the crew members for a stay of six to twelve months on Mars. Two different concepts were investigated, a modular assembly reusable structure (MARS) designated Lavapolis, and a prefabricated space frame structure called Hexamars. Both models take into account factors such as future expansion, radiation shielding, and ease of assembly.

Waveguide metatronics: Lumped circuitry based on structural dispersion

PubMed Central

Li, Yue; Liberal, Iñigo; Della Giovampaola, Cristian; Engheta, Nader

2016-01-01

Engineering optical nanocircuits by exploiting modularization concepts and methods inherited from electronics may lead to multiple innovations in optical information processing at the nanoscale. We introduce the concept of “waveguide metatronics,” an advanced form of optical metatronics that uses structural dispersion in waveguides to obtain the materials and structures required to construct this class of circuitry. Using numerical simulations, we demonstrate that the design of a metatronic circuit can be carried out by using a waveguide filled with materials with positive permittivity. This includes the implementation of all “lumped” circuit elements and their assembly in a single circuit board. In doing so, we extend the concepts of optical metatronics to frequency ranges where there are no natural plasmonic materials available. The proposed methodology could be exploited as a platform to experimentally validate optical metatronic circuits in other frequency regimes, such as microwave frequency setups, and/or to provide a new route to design optical nanocircuitry. PMID:27386566

Nanoparticles and self-organisation: the emergence of hierarchical properties from the nanoparticle soup (i.e., the small is getting bigger). Concluding remarks for Faraday Discussion: Nanoparticle Synthesis and Assembly.

PubMed

Schiffrin, David J

2015-01-01

Some four years ago, one of the participants in this Discussion (Prof. Nicholas Kotov) predicted that: "within five years we shall see multiple examples of electronic, sensor, optical and other devices utilizing self-assembled superstructures" (N. A. Kotov, J. Mater. Chem., 2011, 21, 16673-16674). Although this prediction came partially to fruition, we have witnessed an unprecedented interest in the properties of materials at the nanoscale. The point highlighted by Kotov, however, was the importance of self-assembly of structures from well characterised building blocks to yield hierarchical structures, hopefully with predictable properties, a concept that is an everyday pursuit of synthetic chemists. This Discussion has brought together researchers from a wide range of disciplines, i.e., colloid science, modelling, nanoparticle synthesis and organisation, magnetic and optical materials, and new imaging methods, within the excellent traditional Faraday Discussion format, to discuss advances in areas relevant to the main theme of the meeting.

Self-assembling hydrogel scaffolds for photocatalytic hydrogen production

DOE PAGES

Weingarten, Adam S.; Kazantsev, Roman V.; Palmer, Liam C.; ...

2014-10-05

Integration into a soft material of all the molecular components necessary to generate storable fuels is an interesting target in supramolecular chemistry. The concept is inspired by the internal structure of photosynthetic organelles, such as plant chloroplasts, which colocalize molecules involved in light absorption, charge transport and catalysis to create chemical bonds using light energy. We report in this paper on the light-driven production of hydrogen inside a hydrogel scaffold built by the supramolecular self-assembly of a perylene monoimide amphiphile. The charged ribbons formed can electrostatically attract a nickel-based catalyst, and electrolyte screening promotes gelation. We found the emergent phenomenonmore » that screening by the catalyst or the electrolytes led to two-dimensional crystallization of the chromophore assemblies and enhanced the electronic coupling among the molecules. Finally, photocatalytic production of hydrogen is observed in the three-dimensional environment of the hydrogel scaffold and the material is easily placed on surfaces or in the pores of solid supports.« less

Preliminary design considerations for 10 to 40 meter-diameter precision truss reflectors

NASA Technical Reports Server (NTRS)

Mikulas, Martin M., Jr.; Collins, Timothy J.; Hedgepeth, John M.

1990-01-01

A simplified preliminary design capability for erectable precision segmented reflectors is presented. This design capability permits a rapid assessment of a wide range of reflector parameters as well as new structural concepts and materials. The preliminary design approach was applied to a range of precision reflectors from 10 meters to 100 meters in diameter while considering standard design drivers. The design drivers considered were: weight, fundamental frequency, launch packaging volume, part count, and on-orbit assembly time. For the range of parameters considered, on-orbit assembly time was identified as the major design driver. A family of modular panels is introduced which can significantly reduce the number of reflector parts and the on-orbit assembly time.

Reality-and-Desire in Ciliates

NASA Astrophysics Data System (ADS)

Brijder, Robert; Hoogeboom, Hendrik Jan

The theory of gene assembly in ciliates has a number of similarities with the theory of sorting by reversal. Both theories model processes that are based on splicing, and have a fixed begin and end product. The main difference is the type of splicing operations used to obtain the end product from the begin product. In this overview paper, we show how the concept of breakpoint graph, known from the theory of sorting by reversal, can be used in the theory of gene assembly. Our aim is to present the material in an intuitive and informal manner to allow for an efficient introduction into the subject.

Technology for Large Space Systems: A Special Bibliography with Indexes (Supplement 2)

NASA Technical Reports Server (NTRS)

1980-01-01

This bibliography lists 258 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 1, 1979 and December 31, 1979. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design in the area of the Large Space Systems Technology (LSST) Program. Subject matter is grouped according to systems, interactive analysis and design, structural concepts, control systems, electronics, advanced materials, assembly concepts, propulsion, solar power satellite systems, and flight experiments.

Technology for large space systems: A special bibliography with indexes (supplement 05)

NASA Technical Reports Server (NTRS)

1981-01-01

This bibliography lists 298 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1981 and June 30, 1981. Its purpose is to provide helpful, information to the researcher, manager, and designer in technology development and mission design in the area of the Large Space Systems Technology (LSST) Program. Subject matter is grouped according to systems, interactive analysis and design, structural concepts, control systems, electronics, advanced materials, assembly concepts, propulsion, solar power satellite systems, and flight experiments.

Technology for large space systems: A bibliography with indexes (supplement 12)

NASA Technical Reports Server (NTRS)

1985-01-01

A bibliography listing 516 reports, articles and other documents introduced into the NASA scientific and technical information system between July 1, 1984 and December 31, 1984 is presented. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design in the area of Large Space System Technology. Subject matter is grouped according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems.

Technology for large space systems: A special bibliography with indexes (supplement 06)

NASA Technical Reports Server (NTRS)

1982-01-01

This bibliography lists 220 reports, articles and other documents introduced into the NASA scientific and technical information system between July 1, 1981 and December 31, 1981. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design in the area of the Large Space Systems Technology (LSST) Program. Subject matter is grouped according to systems, interactive analysis and design, structural concepts, control systems, electronics, advanced materials, assembly concepts, propulsion, solar power satellite systems, and flight experiments.

Ruggedizing vibration sensitive components of electro-optical module using wideband dynamic absorber

NASA Astrophysics Data System (ADS)

Veprik, Alexander; Openhaim, Yaki; Babitsky, Vladimir; Tuito, Avi

2018-05-01

In the modern design approach, the cold portion of Integrated Dewar-Detector-Cooler-Assembly (substrate, infrared focal plane array, cold shield and cold filter) is directly mounted upon the distal end of a cold finger of a cryogenic cooler with no mechanical contact with the warm Dewar shroud. This concept allows for essential reduction of parasitic (conductive) heat load. The penalty, however, is that resulting tip-mass cantilever is lightly damped and, therefore, prone to vibrational extremes typical of the modern battlefield. Without sufficient ruggedizing, vibration induced structural resonances may affect image quality and even may cause mechanical failures due to material fatigue. Use of additional front supports or thickening the cold finger walls results in increased parasitic conductive heat load, power consumption and mechanical complexity. The authors explore the concept of wideband dynamic absorber in application to ruggedizing the Integrated Dewar-Detector-Cooler Assembly.

Minimum accommodation for aerobrake assembly. Phase 2: Structural concepts for a lunar transfer vehicle aerobrake which can be assembled on orbit

NASA Technical Reports Server (NTRS)

Dorsey, John T.; Watson, Judith J.; Tutterow, Robin D.

1993-01-01

A multidisciplinary conceptual study was conducted to define a reusable lunar transfer vehicle (LTV) aerobrake which could be launched on a Space Shuttle of Titan 4 and assembled on orbit at Space Station Freedom. A major objective was to design an aerobrake, with integrated structure and thermal protection systems, which has a mass less than 20 percent (9040 lb) of the LTV lunar return mass. The aerobrake segmentation concepts, the structural concepts, a joint concept for assembly, and a structural design with analysis of the aerobrake are described. Results show that a 50-foot diameter LTV aerobrake can be designed for on-orbit assembly which will achieve the 20 percent mass budget.

Mechanical assembly of complex, 3D mesostructures from releasable multilayers of advanced materials.

PubMed

Yan, Zheng; Zhang, Fan; Liu, Fei; Han, Mengdi; Ou, Dapeng; Liu, Yuhao; Lin, Qing; Guo, Xuelin; Fu, Haoran; Xie, Zhaoqian; Gao, Mingye; Huang, Yuming; Kim, JungHwan; Qiu, Yitao; Nan, Kewang; Kim, Jeonghyun; Gutruf, Philipp; Luo, Hongying; Zhao, An; Hwang, Keh-Chih; Huang, Yonggang; Zhang, Yihui; Rogers, John A

2016-09-01

Capabilities for assembly of three-dimensional (3D) micro/nanostructures in advanced materials have important implications across a broad range of application areas, reaching nearly every class of microsystem technology. Approaches that rely on the controlled, compressive buckling of 2D precursors are promising because of their demonstrated compatibility with the most sophisticated planar technologies, where materials include inorganic semiconductors, polymers, metals, and various heterogeneous combinations, spanning length scales from submicrometer to centimeter dimensions. We introduce a set of fabrication techniques and design concepts that bypass certain constraints set by the underlying physics and geometrical properties of the assembly processes associated with the original versions of these methods. In particular, the use of releasable, multilayer 2D precursors provides access to complex 3D topologies, including dense architectures with nested layouts, controlled points of entanglement, and other previously unobtainable layouts. Furthermore, the simultaneous, coordinated assembly of additional structures can enhance the structural stability and drive the motion of extended features in these systems. The resulting 3D mesostructures, demonstrated in a diverse set of more than 40 different examples with feature sizes from micrometers to centimeters, offer unique possibilities in device design. A 3D spiral inductor for near-field communication represents an example where these ideas enable enhanced quality ( Q ) factors and broader working angles compared to those of conventional 2D counterparts.

Mechanical assembly of complex, 3D mesostructures from releasable multilayers of advanced materials

PubMed Central

Yan, Zheng; Zhang, Fan; Liu, Fei; Han, Mengdi; Ou, Dapeng; Liu, Yuhao; Lin, Qing; Guo, Xuelin; Fu, Haoran; Xie, Zhaoqian; Gao, Mingye; Huang, Yuming; Kim, JungHwan; Qiu, Yitao; Nan, Kewang; Kim, Jeonghyun; Gutruf, Philipp; Luo, Hongying; Zhao, An; Hwang, Keh-Chih; Huang, Yonggang; Zhang, Yihui; Rogers, John A.

2016-01-01

Capabilities for assembly of three-dimensional (3D) micro/nanostructures in advanced materials have important implications across a broad range of application areas, reaching nearly every class of microsystem technology. Approaches that rely on the controlled, compressive buckling of 2D precursors are promising because of their demonstrated compatibility with the most sophisticated planar technologies, where materials include inorganic semiconductors, polymers, metals, and various heterogeneous combinations, spanning length scales from submicrometer to centimeter dimensions. We introduce a set of fabrication techniques and design concepts that bypass certain constraints set by the underlying physics and geometrical properties of the assembly processes associated with the original versions of these methods. In particular, the use of releasable, multilayer 2D precursors provides access to complex 3D topologies, including dense architectures with nested layouts, controlled points of entanglement, and other previously unobtainable layouts. Furthermore, the simultaneous, coordinated assembly of additional structures can enhance the structural stability and drive the motion of extended features in these systems. The resulting 3D mesostructures, demonstrated in a diverse set of more than 40 different examples with feature sizes from micrometers to centimeters, offer unique possibilities in device design. A 3D spiral inductor for near-field communication represents an example where these ideas enable enhanced quality (Q) factors and broader working angles compared to those of conventional 2D counterparts. PMID:27679820

Mechanical assembly of complex, 3D mesostructures from releasable multilayers of advanced materials

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

Yan, Zheng; Zhang, Fan; Liu, Fei

Capabilities for assembly of three-dimensional (3D) micro/nanostructures in advanced materials have important implications across a broad range of application areas, reaching nearly every class of microsystem technology. Approaches that rely on the controlled, compressive buckling of 2D precursors are promising because of their demonstrated compatibility with the most sophisticated planar technologies, where materials include inorganic semiconductors, polymers, metals, and various heterogeneous combinations, spanning length scales from submicrometer to centimeter dimensions. We introduce a set of fabrication techniques and design concepts that bypass certain constraints set by the underlying physics and geometrical properties of the assembly processes associated with the originalmore » versions of these methods. In particular, the use of releasable, multilayer 2D precursors provides access to complex 3D topologies, including dense architectures with nested layouts, controlled points of entanglement, and other previously unobtainable layouts. Furthermore, the simultaneous, coordinated assembly of additional structures can enhance the structural stability and drive the motion of extended features in these systems. The resulting 3D mesostructures, demonstrated in a diverse set of more than 40 different examples with feature sizes from micrometers to centimeters, offer unique possibilities in device design. In conclusion, a 3D spiral inductor for near-field communication represents an example where these ideas enable enhanced quality ( Q) factors and broader working angles compared to those of conventional 2D counterparts.« less

Mechanical assembly of complex, 3D mesostructures from releasable multilayers of advanced materials

DOE PAGES

Yan, Zheng; Zhang, Fan; Liu, Fei; ...

2016-09-23

Capabilities for assembly of three-dimensional (3D) micro/nanostructures in advanced materials have important implications across a broad range of application areas, reaching nearly every class of microsystem technology. Approaches that rely on the controlled, compressive buckling of 2D precursors are promising because of their demonstrated compatibility with the most sophisticated planar technologies, where materials include inorganic semiconductors, polymers, metals, and various heterogeneous combinations, spanning length scales from submicrometer to centimeter dimensions. We introduce a set of fabrication techniques and design concepts that bypass certain constraints set by the underlying physics and geometrical properties of the assembly processes associated with the originalmore » versions of these methods. In particular, the use of releasable, multilayer 2D precursors provides access to complex 3D topologies, including dense architectures with nested layouts, controlled points of entanglement, and other previously unobtainable layouts. Furthermore, the simultaneous, coordinated assembly of additional structures can enhance the structural stability and drive the motion of extended features in these systems. The resulting 3D mesostructures, demonstrated in a diverse set of more than 40 different examples with feature sizes from micrometers to centimeters, offer unique possibilities in device design. In conclusion, a 3D spiral inductor for near-field communication represents an example where these ideas enable enhanced quality ( Q) factors and broader working angles compared to those of conventional 2D counterparts.« less

Swing-arm beam erector (SABER) concept for single astronaut assembly of space structure

NASA Technical Reports Server (NTRS)

Watson, J. J.; Heard, W. L., Jr.; Jensen, J. K.

1985-01-01

Results are presented of tests conducted to evaluate a mobile work station/assembly fixture concept that would mechanically assist an astronaut in the on-orbit manual assembly of erectable truss-beams. The concept eliminates astronaut manual translation by use of a motorized work platform with foot restraints. The tests involved assembly of a tetrahedral truss-beam by a test subject in simulated zero gravity (neutral bouyancy in water). A three-bay truss-beam was assembled from 30 aluminum struts with quick-attachment structural joints. The results show that average on-orbit assembly rates of 2.1 struts per minute can be expected for struts of the size employed in these tests.

Autonomous Assembly of Modular Structures in Space and on Extraterrestrial Locations

NASA Astrophysics Data System (ADS)

Alhorn, Dean C.

2005-02-01

The new U.S. National Vision for Space Exploration requires many new enabling technologies to accomplish the goals of space commercialization and returning humans to the moon and extraterrestrial environments. Traditionally, flight elements are complete sub-systems requiring humans to complete the integration and assembly. These bulky structures also require the use of heavy launch vehicles to send the units to a desired location. This philosophy necessitates a high degree of safety, numerous space walks at a significant cost. Future space mission costs must be reduced and safety increased to reasonably achieve exploration goals. One proposed concept is the autonomous assembly of space structures. This concept is an affordable, reliable solution to in-space and extraterrestrial assembly. Assembly is autonomously performed when two components join after determining that specifications are correct. Local sensors continue monitor joint integrity post assembly, which is critical for safety and structural reliability. Achieving this concept requires a change in space structure design philosophy and the development of innovative technologies to perform autonomous assembly. Assembly of large space structures will require significant numbers of integrity sensors. Thus simple, low-cost sensors are integral to the success of this concept. This paper addresses these issues and proposes a novel concept for assembling space structures autonomously. Core technologies required to achieve in space assembly are presented. These core technologies are critical to the goal of utilizing space in a cost efficient and safe manner. Additionally, these novel technologies can be applied to other systems both on earth and extraterrestrial environments.

Autonomous Assembly of Modular Structures in Space and on Extraterrestrial Locations

NASA Technical Reports Server (NTRS)

Alhorn, Dean C.

2005-01-01

The new U.S. National Vision for Space Exploration requires many new enabling technologies to accomplish the goals of space commercialization and returning humans to the moon and extraterrestrial environments. Traditionally, flight elements are complete subsystems requiring humans to complete the integration and assembly. These bulky structures also require the use of heavy launch vehicles to send the units to a desired location. This philosophy necessitates a high degree of safety, numerous space walks at a significant cost. Future space mission costs must be reduced and safety increased to reasonably achieve exploration goals. One proposed concept is the autonomous assembly of space structures. This concept is an affordable, reliable solution to in-space and extraterrestrial assembly. Assembly is autonomously performed when two components join after determining that specifications are correct. Local sensors continue monitor joint integrity post assembly, which is critical for safety and structural reliability. Achieving this concept requires a change in space structure design philosophy and the development of innovative technologies to perform autonomous assembly. Assembly of large space structures will require significant numbers of integrity sensors. Thus simple, low-cost sensors are integral to the success of this concept. This paper addresses these issues and proposes a novel concept for assembling space structures autonomously. Core technologies required to achieve in space assembly are presented. These core technologies are critical to the goal of utilizing space in a cost efficient and safe manner. Additionally, these novel technologies can be applied to other systems both on earth and extraterrestrial environments.

Ordered molecular arrays as templates: A new approach to synthesis of mesoporous materials

NASA Astrophysics Data System (ADS)

Behrens, P.; Stucky, G.

There has been a growing interest in the extension of the microporous molecular sieve synthesis and applications to mesoscopic dimensions. Typical areas for the application of mesoscopic zeolite-type structures are in separation (e.g., protein separation and selective adsorption of large organic molecules from waste waters) and catalysis (e.g., processing of tar sand and of the high distillates of crude oils to valuable low-boiling products). Another is in the supramolecular assembly of molecular array and polymers for electronic and optical applications. In a new concept in the synthesis of porous material the templating agent is no longer a single, solvated, organic molecule or metal ion, but rather a self-assembled molecular array. This template leads to mesoporous materials with adjustable pore sizes between 16 and greater than 100 Angstrom, covering well the mesophorous range of greatest interest. The periodic arrangement of pores is very regular, and the pore size distribution measured by absorption is nearly as sharp as that of conventional zeolites.

DNA-Mediated Patterning of Single Quantum Dot Nanoarrays: A Reusable Platform for Single-Molecule Control

NASA Astrophysics Data System (ADS)

Huang, Da; Freeley, Mark; Palma, Matteo

2017-03-01

We present a facile strategy of general applicability for the assembly of individual nanoscale moieties in array configurations with single-molecule control. Combining the programming ability of DNA as a scaffolding material with a one-step lithographic process, we demonstrate the patterning of single quantum dots (QDs) at predefined locations on silicon and transparent glass surfaces: as proof of concept, clusters of either one, two, or three QDs were assembled in highly uniform arrays with a 60 nm interdot spacing within each cluster. Notably, the platform developed is reusable after a simple cleaning process and can be designed to exhibit different geometrical arrangements.

FAA/NASA International Symposium on Advanced Structural Integrity Methods for Airframe Durability and Damage Tolerance

NASA Technical Reports Server (NTRS)

Harris, Charles E. (Editor)

1994-01-01

International technical experts in durability and damage tolerance of metallic airframe structures were assembled to present and discuss recent research findings and the development of advanced design and analysis methods, structural concepts, and advanced materials. The symposium focused on the dissemination of new knowledge and the peer-review of progress on the development of advanced methodologies. Papers were presented on: structural concepts for enhanced durability, damage tolerance, and maintainability; new metallic alloys and processing technology; fatigue crack initiation and small crack effects; fatigue crack growth models; fracture mechanics failure, criteria for ductile materials; structural mechanics methodology for residual strength and life prediction; development of flight load spectra for design and testing; and advanced approaches to resist corrosion and environmentally assisted fatigue.

FAA/NASA International Symposium on Advanced Structural Integrity Methods for Airframe Durability and Damage Tolerance, part 2

NASA Technical Reports Server (NTRS)

Harris, Charles E. (Editor)

1994-01-01

The international technical experts in the areas of durability and damage tolerance of metallic airframe structures were assembled to present and discuss recent research findings and the development of advanced design and analysis methods, structural concepts, and advanced materials. The principal focus of the symposium was on the dissemination of new knowledge and the peer-review of progress on the development of advanced methodologies. Papers were presented on the following topics: structural concepts for enhanced durability, damage tolerance, and maintainability; new metallic alloys and processing technology; fatigue crack initiation and small crack effects; fatigue crack growth models; fracture mechanics failure criteria for ductile materials; structural mechanics methodology for residual strength and life prediction; development of flight load spectra for design and testing; and corrosion resistance.

Space station systems: A bibliography with indexes (supplement 6)

NASA Technical Reports Server (NTRS)

1988-01-01

This bibliography lists 1,133 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 1, 1987 and December 31, 1987. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems. The coverage includes documents that define major systems and subsystems, servicing and support requirements, procedures and operations, and missions for the current and future Space Station.

Space station systems: A bibliography with indexes (supplement 3)

NASA Technical Reports Server (NTRS)

1987-01-01

This bibliography lists 780 reports, articles and other documents introduced into the NASA scientific and technical information system between January 1, 1986 and June 30, 1986. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite system. The coverage includes documents that define major systems and subsystems, servicing and support requirements, procedures and operations, and missions for the current and future space station.

Space station systems: A bibliography with indexes (supplement 2)

NASA Technical Reports Server (NTRS)

1986-01-01

This bibliography lists 904 reports, articles and other documents introduced into the NASA scientific and technical information system between July 1, 1985 and December 31, 1985. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems. The coverage includes documents that define major systems and subsystems, servicing and support requirements, procedures and operations, and missions for the current and future space station.

Space station systems: A bibliography with indexes

NASA Technical Reports Server (NTRS)

1987-01-01

This bibliography lists 967 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1987 and June 30, 1987. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems. The coverage includes documents that define major systems and subsystems, servicing and support requirements, procedures and operations, and missions for the current and future space station.

Adaptation of a Filter Assembly to Assess Microbial Bioburden of Pressurant Within a Propulsion System

NASA Technical Reports Server (NTRS)

Benardini, James N.; Koukol, Robert C.; Schubert, Wayne W.; Morales, Fabian; Klatte, Marlin F.

2012-01-01

A report describes an adaptation of a filter assembly to enable it to be used to filter out microorganisms from a propulsion system. The filter assembly has previously been used for particulates greater than 2 micrometers. Projects that utilize large volumes of nonmetallic materials of planetary protection concern pose a challenge to their bioburden budget, as a conservative specification value of 30 spores per cubic centimeter is typically used. Helium was collected utilizing an adapted filtration approach employing an existing Millipore filter assembly apparatus used by the propulsion team for particulate analysis. The filter holder on the assembly has a 47-mm diameter, and typically a 1.2-5 micrometer pore-size filter is used for particulate analysis making it compatible with commercially available sterilization filters (0.22 micrometers) that are necessary for biological sampling. This adaptation to an existing technology provides a proof-of-concept and a demonstration of successful use in a ground equipment system. This adaptation has demonstrated that the Millipore filter assembly can be utilized to filter out microorganisms from a propulsion system, whereas in previous uses the filter assembly was utilized for particulates greater than 2 micrometers.

Large space systems technology electronics: Data and power distribution

NASA Technical Reports Server (NTRS)

Dunbar, W. G.

1980-01-01

The development of hardware technology and manufacturing techniques required to meet space platform and antenna system needs in the 1980s is discussed. Preliminary designs for manned and automatically assembled space power system cables, connectors, and grounding and bonding materials and techniques are reviewed. Connector concepts, grounding design requirements, and bonding requirements are discussed. The problem of particulate debris contamination for large structure spacecraft is addressed.

Applications of Graphene-Modified Electrodes in Microbial Fuel Cells

PubMed Central

Yu, Fei; Wang, Chengxian; Ma, Jie

2016-01-01

Graphene-modified materials have captured increasing attention for energy applications due to their superior physical and chemical properties, which can significantly enhance the electricity generation performance of microbial fuel cells (MFC). In this review, several typical synthesis methods of graphene-modified electrodes, such as graphite oxide reduction methods, self-assembly methods, and chemical vapor deposition, are summarized. According to the different functions of the graphene-modified materials in the MFC anode and cathode chambers, a series of design concepts for MFC electrodes are assembled, e.g., enhancing the biocompatibility and improving the extracellular electron transfer efficiency for anode electrodes and increasing the active sites and strengthening the reduction pathway for cathode electrodes. In spite of the challenges of MFC electrodes, graphene-modified electrodes are promising for MFC development to address the reduction in efficiency brought about by organic waste by converting it into electrical energy. PMID:28773929

Internally resonating lattices for bandgap generation and low-frequency vibration control

NASA Astrophysics Data System (ADS)

Baravelli, Emanuele; Ruzzene, Massimo

2013-12-01

The paper reports on a structural concept for high stiffness and high damping performance. A stiff external frame and an internal resonating lattice are combined in a beam-like assembly which is characterized by high frequency bandgaps and tuned vibration attenuation at low frequencies. The resonating lattice consists of an elastomeric material arranged according to a chiral topology which is designed to resonate at selected frequencies. The concept achieves high damping performance by combining the frequency-selective properties of internally resonating structures, with the energy dissipation characteristics of their constituent material. The flexible ligaments, the circular nodes and the non-central interactions of the chiral topology lead to dynamic deformation patterns which are beneficial to energy dissipation. Furthermore, tuning and grading of the elements of the lattice allows for tailoring of the resonating properties so that vibration attenuation is obtained over desired frequency ranges. Numerical and experimental results demonstrate the tuning flexibility of this concept and suggest its potential application for load-carrying structural members parts of vibration and shock prone systems.

Critical processes and parameters in the development of accident tolerant fuels drop-in capsule irradiation tests

DOE PAGES

Barrett, K. E.; Ellis, K. D.; Glass, C. R.; ...

2015-12-01

The goal of the Accident Tolerant Fuel (ATF) program is to develop the next generation of Light Water Reactor (LWR) fuels with improved performance, reliability, and safety characteristics during normal operations and accident conditions and with reduced waste generation. An irradiation test series has been defined to assess the performance of proposed ATF concepts under normal LWR operating conditions. The Phase I ATF irradiation test series is planned to be performed as a series of drop-in capsule tests to be irradiated in the Advanced Test Reactor (ATR) operated by the Idaho National Laboratory (INL). Design, analysis, and fabrication processes formore » ATR drop-in capsule experiment preparation are presented in this paper to demonstrate the importance of special design considerations, parameter sensitivity analysis, and precise fabrication and inspection techniques for figure innovative materials used in ATF experiment assemblies. A Taylor Series Method sensitivity analysis approach was used to identify the most critical variables in cladding and rodlet stress, temperature, and pressure calculations for design analyses. The results showed that internal rodlet pressure calculations are most sensitive to the fission gas release rate uncertainty while temperature calculations are most sensitive to cladding I.D. and O.D. dimensional uncertainty. The analysis showed that stress calculations are most sensitive to rodlet internal pressure uncertainties, however the results also indicated that the inside radius, outside radius, and internal pressure were all magnified as they propagate through the stress equation. This study demonstrates the importance for ATF concept development teams to provide the fabricators as much information as possible about the material properties and behavior observed in prototype testing, mock-up fabrication and assembly, and chemical and mechanical testing of the materials that may have been performed in the concept development phase. Special handling, machining, welding, and inspection of materials, if known, should also be communicated to the experiment fabrication and inspection team.« less

Mobile work station concept for assembly of large space structures (zero gravity simulation tests)

NASA Astrophysics Data System (ADS)

Heard, W. L., Jr.; Bush, H. G.; Wallsom, R. E.; Jensen, J. K.

1982-03-01

The concept presented is intended to enhance astronaut assembly of truss structure that is either too large or complex to fold for efficient Shuttle delivery to orbit. The potential of augmented astronaut assembly is illustrated by applying the result of the tests to a barebones assembly of a truss structure. If this structure were assembled from the same nestable struts that were used in the Mobile Work Station assembly tests, the spacecraft would be 55 meters in diameter and consist of about 500 struts. The struts could be packaged in less than 1/2% of the Shuttle cargo bay volume and would take up approximately 3% of the mass lift capability. They could be assembled in approximately four hours. This assembly concept for erectable structures is not only feasible, but could be used to significant economic advantage by permitting the superior packaging feature of erectable structures to be exploited and thereby reduce expensive Shuttle delivery flights.

Mobile work station concept for assembly of large space structures (zero gravity simulation tests)

NASA Technical Reports Server (NTRS)

Heard, W. L., Jr.; Bush, H. G.; Wallsom, R. E.; Jensen, J. K.

1982-01-01

The concept presented is intended to enhance astronaut assembly of truss structure that is either too large or complex to fold for efficient Shuttle delivery to orbit. The potential of augmented astronaut assembly is illustrated by applying the result of the tests to a barebones assembly of a truss structure. If this structure were assembled from the same nestable struts that were used in the Mobile Work Station assembly tests, the spacecraft would be 55 meters in diameter and consist of about 500 struts. The struts could be packaged in less than 1/2% of the Shuttle cargo bay volume and would take up approximately 3% of the mass lift capability. They could be assembled in approximately four hours. This assembly concept for erectable structures is not only feasible, but could be used to significant economic advantage by permitting the superior packaging feature of erectable structures to be exploited and thereby reduce expensive Shuttle delivery flights.

Self-assembled three dimensional network designs for soft electronics

PubMed Central

Jang, Kyung-In; Li, Kan; Chung, Ha Uk; Xu, Sheng; Jung, Han Na; Yang, Yiyuan; Kwak, Jean Won; Jung, Han Hee; Song, Juwon; Yang, Ce; Wang, Ao; Liu, Zhuangjian; Lee, Jong Yoon; Kim, Bong Hoon; Kim, Jae-Hwan; Lee, Jungyup; Yu, Yongjoon; Kim, Bum Jun; Jang, Hokyung; Yu, Ki Jun; Kim, Jeonghyun; Lee, Jung Woo; Jeong, Jae-Woong; Song, Young Min; Huang, Yonggang; Zhang, Yihui; Rogers, John A.

2017-01-01

Low modulus, compliant systems of sensors, circuits and radios designed to intimately interface with the soft tissues of the human body are of growing interest, due to their emerging applications in continuous, clinical-quality health monitors and advanced, bioelectronic therapeutics. Although recent research establishes various materials and mechanics concepts for such technologies, all existing approaches involve simple, two-dimensional (2D) layouts in the constituent micro-components and interconnects. Here we introduce concepts in three-dimensional (3D) architectures that bypass important engineering constraints and performance limitations set by traditional, 2D designs. Specifically, open-mesh, 3D interconnect networks of helical microcoils formed by deterministic compressive buckling establish the basis for systems that can offer exceptional low modulus, elastic mechanics, in compact geometries, with active components and sophisticated levels of functionality. Coupled mechanical and electrical design approaches enable layout optimization, assembly processes and encapsulation schemes to yield 3D configurations that satisfy requirements in demanding, complex systems, such as wireless, skin-compatible electronic sensors. PMID:28635956

Self-assembled three dimensional network designs for soft electronics

NASA Astrophysics Data System (ADS)

Jang, Kyung-In; Li, Kan; Chung, Ha Uk; Xu, Sheng; Jung, Han Na; Yang, Yiyuan; Kwak, Jean Won; Jung, Han Hee; Song, Juwon; Yang, Ce; Wang, Ao; Liu, Zhuangjian; Lee, Jong Yoon; Kim, Bong Hoon; Kim, Jae-Hwan; Lee, Jungyup; Yu, Yongjoon; Kim, Bum Jun; Jang, Hokyung; Yu, Ki Jun; Kim, Jeonghyun; Lee, Jung Woo; Jeong, Jae-Woong; Song, Young Min; Huang, Yonggang; Zhang, Yihui; Rogers, John A.

2017-06-01

Low modulus, compliant systems of sensors, circuits and radios designed to intimately interface with the soft tissues of the human body are of growing interest, due to their emerging applications in continuous, clinical-quality health monitors and advanced, bioelectronic therapeutics. Although recent research establishes various materials and mechanics concepts for such technologies, all existing approaches involve simple, two-dimensional (2D) layouts in the constituent micro-components and interconnects. Here we introduce concepts in three-dimensional (3D) architectures that bypass important engineering constraints and performance limitations set by traditional, 2D designs. Specifically, open-mesh, 3D interconnect networks of helical microcoils formed by deterministic compressive buckling establish the basis for systems that can offer exceptional low modulus, elastic mechanics, in compact geometries, with active components and sophisticated levels of functionality. Coupled mechanical and electrical design approaches enable layout optimization, assembly processes and encapsulation schemes to yield 3D configurations that satisfy requirements in demanding, complex systems, such as wireless, skin-compatible electronic sensors.

Overview of a flywheel stack energy storage system

NASA Technical Reports Server (NTRS)

Kirk, James A.; Anand, Davinder K.

1988-01-01

The concept of storing electrical energy in rotating flywheels provides an attractive substitute to batteries. To realize these advantages the critical technologies of rotor design, composite materials, magnetic suspension, and high efficiency motor/generators are reviewed in this paper. The magnetically suspended flywheel energy storage system, currently under development at the University of Maryland, consisting of a family of interference assembled rings, is presented as an integrated solution for energy storage.

Thermal-structural design study of an airframe-integrated Scramjet

NASA Technical Reports Server (NTRS)

Killackey, J. J.; Katinsky, E. A.; Tepper, S.; Vuigner, A. A.

1978-01-01

Design concepts are developed and evaluated for a cooled structures assembly for the Scramjet engine, for engine subsystems mass, volume, and operating requirements, and for the aircraft/engine interface. A thermal protection system was defined that makes it possible to attain a life of 100 hours and 1000 cycles. The coolant equivalence ratio at the Mach 10 maximum thermal loading condition is 0.6, indicating a capacity for airframe cooling. The mechanical design is feasible for manufacture using conventional materials. For the cooled structures in a six-module engine, the mass per unit capture area is 12.4 KN/sq m. The total weight of a six-module engine assembly including the fuel system is 14.73 KN.

Space assembly fixtures and aids

NASA Technical Reports Server (NTRS)

Bloom, K. A.; Lillenas, A. N.

1980-01-01

Concepts and requirements for assembly fixtures and aids necessary for the assembly and maintenance of spare platforms were studied. Emphasis was placed on erectable and deployable type structures with the shuttle orbiter as the assembly base. Both single and multiple orbiter flight cases for the platform assembly were considered. Applicable space platform assembly studies were reviewed to provide a data base for establishing the assembly fixture and aids design requirements, assembly constraints, and the development of representative design concepts. Conclusions indicated that fixture requirements will vary with platform size. Larger platforms will require translation relative to the orbiter RMS working volume. The installation of platform payloads and subsystems (e.g., utility distribution) must also be considered in the specification of assembly fixtures and aids.

Design and evaluation of low cost blades for large wind driven generating systems

NASA Technical Reports Server (NTRS)

Eggert, W. S.

1982-01-01

The development and evaluation of a low cost blade concept based on the NASA-Lewis specifications is discussed. A blade structure was designed and construction methods and materials were selected. Complete blade tooling concepts, various technical and economic analysis, and evaluations of the blade design were performed. A comprehensive fatigue test program was conducted to provide data and to verify the design. A test specimen of the spar assembly, including the root end attachment, was fabricated. This is a full-scale specimen of the root end configuration, 20 ft long. A blade design for the Mod '0' system was completed.

Direct-Write Printing on Three-Dimensional Geometries for Miniaturized Detector and Electronic Assemblies

NASA Technical Reports Server (NTRS)

Paquette, Beth; Samuels, Margaret; Chen, Peng

2017-01-01

Direct-write printing techniques will enable new detector assemblies that were not previously possible with traditional assembly processes. Detector concepts were manufactured using this technology to validate repeatability. Additional detector applications and printed wires on a 3-dimensional magnetometer bobbin will be designed for print. This effort focuses on evaluating performance for direct-write manufacturing techniques on 3-dimensional surfaces. Direct-write manufacturing has the potential to reduce mass and volume for fabrication and assembly of advanced detector concepts by reducing trace widths down to 10 microns, printing on complex geometries, allowing new electronic concept production, and reduced production times of complex those electronics.

HabEx Optical Telescope Assembly

NASA Technical Reports Server (NTRS)

Stahl, H. Philip

2017-01-01

Purpose: a) Introduce candidate optical telescope assembly (OTA) architectures. b) Illustrate design/analysis process. Agenda: a) Definitions, Specification & Assumptions. b.) 4-meter Monolithic Mirror Concept. c) 6.5-meter Segmented Mirror Concept.

Lunar base thermoelectric power station study

NASA Technical Reports Server (NTRS)

Determan, William; Frye, Patrick; Mondt, Jack; Fleurial, Jean-Pierre; Johnson, Ken; Stapfer, G.; Brooks, Michael D.; Heshmatpour, Ben

2006-01-01

Under NASA's Project Prometheus, the Nuclear Systems Program, the Jet Propulsion Laboratory, Pratt & Whitney Rocketdyne, and Teledyne Energy Systems have teamed with a number of universities, under the Segmented Thermoelectric Multicouple Converter (STMC) program, to develop the next generation of advanced thermoelectric converters for space reactor power systems. Work on the STMC converter assembly has progressed to the point where the lower temperature stage of the segmented multicouple converter assembly is ready for laboratory testing and the upper stage materials have been identified and their properties are being characterized. One aspect of the program involves mission application studies to help define the potential benefits from the use of these STMC technologies for designated NASA missions such as the lunar base power station where kilowatts of power are required to maintain a permanent manned presence on the surface of the moon. A modular 50 kWe thermoelectric power station concept was developed to address a specific set of requirements developed for this mission. Previous lunar lander concepts had proposed the use of lunar regolith as in-situ radiation shielding material for a reactor power station with a one kilometer exclusion zone radius to minimize astronaut radiation dose rate levels. In the present concept, we will examine the benefits and requirements for a hermetically-sealed reactor thermoelectric power station module suspended within a man-made lunar surface cavity. The concept appears to maximize the shielding capabilities of the lunar regolith while minimizing its handling requirements. Both thermal and nuclear radiation levels from operation of the station, at its 100-m exclusion zone radius, were evaluated and found to be acceptable. Site preparation activities are reviewed and well as transport issues for this concept. The goal of the study was to review the entire life cycle of the unit to assess its technical problems and technology needs in all areas to support the development, deployment, operation and disposal of the unit.

A mobile work station concept for mechanically aided astronaut assembly of large space trusses

NASA Technical Reports Server (NTRS)

Heard, W. L., Jr.; Bush, H. G.; Wallson, R. E.; Jensen, J. K.

1983-01-01

This report presents results of a series of truss assembly tests conducted to evaluate a mobile work station concept intended to mechanically assist astronaut manual assembly of erectable space trusses. The tests involved assembly of a tetrahedral truss beam by a pair of test subjects with and without pressure (space) suits, both in Earth gravity and in simulated zero gravity (neutral buoyancy in water). The beam was assembled from 38 identical graphite-epoxy nestable struts, 5.4 m in length with aluminum quick-attachment structural joints. Struts and joints were designed to closely simulate flight hardware. The assembled beam was approximately 16.5 m long and 4.5 m on each of the four sides of its diamond-shaped cross section. The results show that average in-space assembly rates of approximately 38 seconds per strut can be expected for struts of comparable size. This result is virtually independent of the overall size of the structure being assembled. The mobile work station concept would improve astronaut efficiency for on-orbit manual assembly of truss structures, and also this assembly-line method is highly competitive with other construction methods being considered for large space structures.

Mimicking electrodeposition in the gas phase: a programmable concept for selected-area fabrication of multimaterial nanostructures.

PubMed

Cole, Jesse J; Lin, En-Chiang; Barry, Chad R; Jacobs, Heiko O

2010-05-21

An in situ gas-phase process that produces charged streams of Au, Si, TiO(2), ZnO, and Ge nanoparticles/clusters is reported together with a programmable concept for selected-area assembly/printing of more than one material type. The gas-phase process mimics solution electrodeposition whereby ions in the liquid phase are replaced with charged clusters in the gas phase. The pressure range in which the analogy applies is discussed and it is demonstrated that particles can be plated into pores vertically (minimum resolution 60 nm) or laterally to form low-resistivity (48 microOmega cm) interconnects. The process is applied to the formation of multimaterial nanoparticle films and sensors. The system works at atmospheric pressure and deposits material at room temperature onto electrically biased substrate regions. The combination of pumpless operation and parallel nozzle-free deposition provides a scalable tool for printable flexible electronics and the capability to mix and match materials.

Layer-by-layer assembly of two-dimensional materials into wafer-scale heterostructures

NASA Astrophysics Data System (ADS)

Kang, Kibum; Lee, Kan-Heng; Han, Yimo; Gao, Hui; Xie, Saien; Muller, David A.; Park, Jiwoong

2017-10-01

High-performance semiconductor films with vertical compositions that are designed to atomic-scale precision provide the foundation for modern integrated circuitry and novel materials discovery. One approach to realizing such films is sequential layer-by-layer assembly, whereby atomically thin two-dimensional building blocks are vertically stacked, and held together by van der Waals interactions. With this approach, graphene and transition-metal dichalcogenides--which represent one- and three-atom-thick two-dimensional building blocks, respectively--have been used to realize previously inaccessible heterostructures with interesting physical properties. However, no large-scale assembly method exists at present that maintains the intrinsic properties of these two-dimensional building blocks while producing pristine interlayer interfaces, thus limiting the layer-by-layer assembly method to small-scale proof-of-concept demonstrations. Here we report the generation of wafer-scale semiconductor films with a very high level of spatial uniformity and pristine interfaces. The vertical composition and properties of these films are designed at the atomic scale using layer-by-layer assembly of two-dimensional building blocks under vacuum. We fabricate several large-scale, high-quality heterostructure films and devices, including superlattice films with vertical compositions designed layer-by-layer, batch-fabricated tunnel device arrays with resistances that can be tuned over four orders of magnitude, band-engineered heterostructure tunnel diodes, and millimetre-scale ultrathin membranes and windows. The stacked films are detachable, suspendable and compatible with water or plastic surfaces, which will enable their integration with advanced optical and mechanical systems.

Layer-by-layer assembly of two-dimensional materials into wafer-scale heterostructures.

PubMed

Kang, Kibum; Lee, Kan-Heng; Han, Yimo; Gao, Hui; Xie, Saien; Muller, David A; Park, Jiwoong

2017-10-12

High-performance semiconductor films with vertical compositions that are designed to atomic-scale precision provide the foundation for modern integrated circuitry and novel materials discovery. One approach to realizing such films is sequential layer-by-layer assembly, whereby atomically thin two-dimensional building blocks are vertically stacked, and held together by van der Waals interactions. With this approach, graphene and transition-metal dichalcogenides-which represent one- and three-atom-thick two-dimensional building blocks, respectively-have been used to realize previously inaccessible heterostructures with interesting physical properties. However, no large-scale assembly method exists at present that maintains the intrinsic properties of these two-dimensional building blocks while producing pristine interlayer interfaces, thus limiting the layer-by-layer assembly method to small-scale proof-of-concept demonstrations. Here we report the generation of wafer-scale semiconductor films with a very high level of spatial uniformity and pristine interfaces. The vertical composition and properties of these films are designed at the atomic scale using layer-by-layer assembly of two-dimensional building blocks under vacuum. We fabricate several large-scale, high-quality heterostructure films and devices, including superlattice films with vertical compositions designed layer-by-layer, batch-fabricated tunnel device arrays with resistances that can be tuned over four orders of magnitude, band-engineered heterostructure tunnel diodes, and millimetre-scale ultrathin membranes and windows. The stacked films are detachable, suspendable and compatible with water or plastic surfaces, which will enable their integration with advanced optical and mechanical systems.

Direct patterning of a cyclotriveratrylene derivative for directed self-assembly of C60

NASA Astrophysics Data System (ADS)

Osner, Zachary R.; Nyamjav, Dorjderem; Holz, Richard C.; Becker, Daniel P.

2011-07-01

A novel apex-modified cyclotriveratrylene (CTV) derivative with an attached thiolane-containing lipoic acid linker was directly patterned onto gold substrates via dip-pen nanolithography (DPN). The addition of a dithiolane-containing linker to the apex of CTV provides a molecule that can adhere to a gold surface with its bowl-shaped cavity directed away from the surface, thereby providing a surface-bound CTV host that can be used for the directed assembly of guest molecules. Subsequent exposure of these CTV microarrays to C60 in toluene resulted in the directed assembly of predesigned, spatially controlled, high-density microarrays of C60. The molecular recognition capabilities of this CTV template toward C60 provides proof-of-concept that supramolecular CTV scaffolds can be directly patterned onto surfaces providing a foundation for the development of organic electronic and optoelectronic materials.

Isochronic carrier-envelope phase-shift compensator.

PubMed

Görbe, Mihaly; Osvay, Karoly; Grebing, Christian; Steinmeyer, Günter

2008-11-15

A concept for orthogonal control of phase and group delay inside a laser cavity by a specially designed compensator assembly is discussed. Similar to the construction of variable polarization retarder, this assembly consists of two thin wedge prisms made from appropriately chosen optical materials. Being shifted as a whole, the assembly allows changing the phase delay with no influence on the cavity round-trip time, whereas relative shifting of the prisms enables adjustment of the latter. This scheme is discussed theoretically and verified experimentally, indicating a factor 30 reduction of the influence on the repetition rate compared to the commonly used silica wedge pair. For a 2pi adjustment of the carrier-envelope phase shift, single-pass timing differences are reduced to the single-femtosecond regime. With negligible distortions of timing and dispersion, the described compensator device greatly simplifies carrier-envelope phase control and experiments in extreme nonlinear optics. Copyright (c) 2008 Optical Society of America.

Structurally adaptive space crane concept for assembling space systems on orbit

NASA Technical Reports Server (NTRS)

Dorsey, John T.; Sutter, Thomas R.; Wu, K. Chauncey

1992-01-01

Many future human space exploration missions will probably require large vehicles that must be assembled on orbit. Thus, a device that can move, position, and assemble large and massive spacecraft components on orbit becomes essential for these missions. A concept is described for such a device: a space crane concept that uses erectable truss hardware to achieve high-stiffness and low-mass booms and uses articulating truss joints that can be assembled on orbit. The hardware has been tested and shown to have linear load-deflection response and to be structurally predictable. The hardware also permits the crane to be reconfigured into different geometries to satisfy future assembly requirements. A number of articulating and rotary joint concepts have been sized and analyzed, and the results are discussed. Two strategies were proposed to suppress motion-induced vibration: placing viscous dampers in selected truss struts and preshaping motion commands. Preliminary analyses indicate that these techniques have the potential to greatly enhance structural damping.

Symposium on Space Industrialization, Huntsville, Ala., May 26, 27, 1976, Proceedings

NASA Technical Reports Server (NTRS)

1976-01-01

Space habitats are considered, with attention given the evolution of space station systems, space station habitability, space settlement planning methodology, and orbital assembly. Various aspects of the Space Transportation System are discussed, including Shuttle booster/propulsion growth concept, advanced earth orbital transportation systems technology, single-stage-to-orbit vehicles and aeromaneuvering orbit transfer vehicles. Materials processing in space is examined, with emphasis on biological materials, metallurgical materials, the uses of space ultrahigh vacuum, and extraterrestrial mining and industrial processing. Solar space power is investigated, with attention given the potential of satellite solar power stations, thermal engine power satellites and microwave power transmission to earth. Individual items are announced in this issue.

Genetically encoded lipid-polypeptide hybrid biomaterials that exhibit temperature-triggered hierarchical self-assembly

NASA Astrophysics Data System (ADS)

Mozhdehi, Davoud; Luginbuhl, Kelli M.; Simon, Joseph R.; Dzuricky, Michael; Berger, Rüdiger; Varol, H. Samet; Huang, Fred C.; Buehne, Kristen L.; Mayne, Nicholas R.; Weitzhandler, Isaac; Bonn, Mischa; Parekh, Sapun H.; Chilkoti, Ashutosh

2018-05-01

Post-translational modification of proteins is a strategy widely used in biological systems. It expands the diversity of the proteome and allows for tailoring of both the function and localization of proteins within cells as well as the material properties of structural proteins and matrices. Despite their ubiquity in biology, with a few exceptions, the potential of post-translational modifications in biomaterials synthesis has remained largely untapped. As a proof of concept to demonstrate the feasibility of creating a genetically encoded biohybrid material through post-translational modification, we report here the generation of a family of three stimulus-responsive hybrid materials—fatty-acid-modified elastin-like polypeptides—using a one-pot recombinant expression and post-translational lipidation methodology. These hybrid biomaterials contain an amphiphilic domain, composed of a β-sheet-forming peptide that is post-translationally functionalized with a C14 alkyl chain, fused to a thermally responsive elastin-like polypeptide. They exhibit temperature-triggered hierarchical self-assembly across multiple length scales with varied structure and material properties that can be controlled at the sequence level.

Design of internal support structures for an inflatable lunar habitat

NASA Technical Reports Server (NTRS)

Cameron, Elizabeth A.; Duston, John A.; Lee, David D.

1990-01-01

NASA has a long range goal of constructing a fully equipped, manned lunar outpost on the near side of the moon by the year 2015. The proposed outpost includes an inflatable lunar habitat to support crews during missions longer that 12 months. A design for the internal support structures of the inflatable habitat is presented. The design solution includes material selection, substructure design, assembly plan development, and concept scale model construction. Alternate designs and design solutions for each component of the design are discussed. Alternate materials include aluminum, titanium, and reinforced polymers. Vertical support alternates include column systems, truss systems, suspension systems, and lunar lander supports. Horizontal alternates include beams, trusses, floor/truss systems, and expandable trusses. Feasibility studies on each alternate showed that truss systems and expandable trusses were the most feasible candidates for conceptual design. The team based the designs on the properties of 7075 T73 aluminum. The substructure assembly plan, minimizes assembly time and allows crews to construct the habitat without the use of EVA suits. In addition to the design solutions, the report gives conclusions and recommendations for further study of the inflatable habitat design.

Analytical Verifications in Cryogenic Testing of NGST Advanced Mirror System Demonstrators

NASA Technical Reports Server (NTRS)

Cummings, Ramona; Levine, Marie; VanBuren, Dave; Kegley, Jeff; Green, Joseph; Hadaway, James; Presson, Joan; Cline, Todd; Stahl, H. Philip (Technical Monitor)

2002-01-01

Ground based testing is a critical and costly part of component, assembly, and system verifications of large space telescopes. At such tests, however, with integral teamwork by planners, analysts, and test personnel, segments can be included to validate specific analytical parameters and algorithms at relatively low additional cost. This paper opens with strategy of analytical verification segments added to vacuum cryogenic testing of Advanced Mirror System Demonstrator (AMSD) assemblies. These AMSD assemblies incorporate material and architecture concepts being considered in the Next Generation Space Telescope (NGST) design. The test segments for workmanship testing, cold survivability, and cold operation optical throughput are supplemented by segments for analytical verifications of specific structural, thermal, and optical parameters. Utilizing integrated modeling and separate materials testing, the paper continues with support plan for analyses, data, and observation requirements during the AMSD testing, currently slated for late calendar year 2002 to mid calendar year 2003. The paper includes anomaly resolution as gleaned by authors from similar analytical verification support of a previous large space telescope, then closes with draft of plans for parameter extrapolations, to form a well-verified portion of the integrated modeling being done for NGST performance predictions.

Performance of Transuranic-Loaded Fully Ceramic Micro-Encapsulated Fuel in LWRs Final Report, Including Void Reactivity Evaluation

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

Michael A. Pope; R. Sonat Sen; Brian Boer

2011-09-01

The current focus of the Deep Burn Project is on once-through burning of transuranics (TRU) in light-water reactors (LWRs). The fuel form is called Fully-Ceramic Micro-encapsulated (FCM) fuel, a concept that borrows the tri-isotropic (TRISO) fuel particle design from high-temperature reactor technology. In the Deep Burn LWR (DB-LWR) concept, these fuel particles are pressed into compacts using SiC matrix material and loaded into fuel pins for use in conventional LWRs. The TRU loading comes from the spent fuel of a conventional LWR after 5 years of cooling. Unit cell and assembly calculations have been performed using the DRAGON-4 code tomore » assess the physics attributes of TRU-only FCM fuel in an LWR lattice. Depletion calculations assuming an infinite lattice condition were performed with calculations of various reactivity coefficients performed at each step. Unit cells and assemblies containing typical UO2 and mixed oxide (MOX) fuel were analyzed in the same way to provide a baseline against which to compare the TRU-only FCM fuel. Then, assembly calculations were performed evaluating the performance of heterogeneous arrangements of TRU-only FCM fuel pins along with UO2 pins.« less

Technology for large space systems: A bibliography with indexes (supplement 20)

NASA Technical Reports Server (NTRS)

1989-01-01

This bibliography lists 694 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System between July, 1988 and December, 1988. Its purpose is to provide helpful information to the researcher or manager engaged in the development of technologies related to large space systems. Subject areas include mission and program definition, design techniques, structural and thermal analysis, structural dynamics and control systems, electronics, advanced materials, assembly concepts, and propulsion.

Materials and structures

NASA Astrophysics Data System (ADS)

Saito, Theodore T.; Langenbeck, Sharon L.; Al-Jamily, Ghanim; Arnold, Joe; Barbee, Troy; Coulter, Dan; Dolgin, Ben; Fichter, Buck; George, Patricia; Gorenstein, Paul

1992-08-01

Materials and structures technology covers a wide range of technical areas. Some of the most pertinent issues for the Astrotech 21 missions include dimensionally stable structural materials, advanced composites, dielectric coatings, optical metallic coatings for low scattered light applications, low scattered light surfaces, deployable and inflatable structures (including optical), support structures in 0-g and 1-g environments, cryogenic optics, optical blacks, contamination hardened surfaces, radiation hardened glasses and crystals, mono-metallic telescopes and instruments, and materials characterization. Some specific examples include low coefficients of thermal expansion (CTE) structures (0.01 ppm/K), lightweight thermally stable mirror materials, thermally stable optical assemblies, high reliability/accuracy (1 micron) deployable structures, and characterization of nanometer level behavior of materials/structures for interferometry concepts. Large filled-aperture concepts will require materials with CTE's of 10(exp 9) at 80 K, anti-contamination coatings, deployable and erectable structures, composite materials with CTE's less than 0.01 ppm/K and thermal hysteresis, 0.001 ppm/K. Gravitational detection systems such as LAGOS will require rigid/deployable structures, dimensionally stable components, lightweight materials with low conductivity, and high stability optics. The Materials and Structures panel addressed these issues and the relevance of the Astrotech 21 mission requirements by dividing materials and structures technology into five categories. These categories, the necessary development, and applicable mission/program development phasing are summarized. For each of these areas, technology assessments were made and development plans were defined.

A Conceptual Aerospace Vehicle Structural System Modeling, Analysis and Design Process

NASA Technical Reports Server (NTRS)

Mukhopadhyay, Vivek

2007-01-01

A process for aerospace structural concept analysis and design is presented, with examples of a blended-wing-body fuselage, a multi-bubble fuselage concept, a notional crew exploration vehicle, and a high altitude long endurance aircraft. Aerospace vehicle structures must withstand all anticipated mission loads, yet must be designed to have optimal structural weight with the required safety margins. For a viable systems study of advanced concepts, these conflicting requirements must be imposed and analyzed early in the conceptual design cycle, preferably with a high degree of fidelity. In this design process, integrated multidisciplinary analysis tools are used in a collaborative engineering environment. First, parametric solid and surface models including the internal structural layout are developed for detailed finite element analyses. Multiple design scenarios are generated for analyzing several structural configurations and material alternatives. The structural stress, deflection, strain, and margins of safety distributions are visualized and the design is improved. Over several design cycles, the refined vehicle parts and assembly models are generated. The accumulated design data is used for the structural mass comparison and concept ranking. The present application focus on the blended-wing-body vehicle structure and advanced composite material are also discussed.

Tests of an alternate mobile transporter and extravehicular activity assembly procedure for the Space Station Freedom truss

NASA Technical Reports Server (NTRS)

Heard, Walter L., Jr.; Watson, Judith J.; Lake, Mark S.; Bush, Harold G.; Jensen, J. Kermit; Wallsom, Richard E.; Phelps, James E.

1992-01-01

Results are presented from a ground test program of an alternate mobile transporter (MT) concept and extravehicular activity (EVA) assembly procedure for the Space Station Freedom (SSF) truss keel. A three-bay orthogonal tetrahedral truss beam consisting of 44 2-in-diameter struts and 16 nodes was assembled repeatedly in neutral buoyancy by pairs of pressure-suited test subjects working from astronaut positioning devices (APD's) on the MT. The truss bays were cubic with edges 15 ft long. All the truss joint hardware was found to be EVA compatible. The average unit assembly time for a single pair of experienced test subjects was 27.6 sec/strut, which is about half the time derived from other SSF truss assembly tests. A concept for integration of utility trays during truss assembly is introduced and demonstrated in the assembly tests. The concept, which requires minimal EVA handling of the trays, is shown to have little impact on overall assembly time. The results of these tests indicate that by using an MT equipped with APD's, rapid EVA assembly of a space station-size truss structure can be expected.

Th and U fuel photofission study by NTD for AD-MSR subcritical assembly

NASA Astrophysics Data System (ADS)

Sajo-Bohus, Laszlo; Greaves, Eduardo D.; Davila, Jesus; Barros, Haydn; Pino, Felix; Barrera, Maria T.; Farina, Fulvio

2015-07-01

During the last decade a considerable effort has been devoted for developing energy generating systems based on advanced nuclear technology within the design concepts of GEN-IV. Thorium base fuel systems such as accelerator driven nuclear reactors are one of the often mentioned attractive and affordable options. Several radiotherapy linear accelerators are on the market and due to their reliability, they could be employed as drivers for subcritical liquid fuel assemblies. Bremsstrahlung photons with energies above 5.5MeV, induce (γ,n) and (e,e'n) reactions in the W-target. Resulting gamma radiation and photo or fission neutrons may be absorbed in target materials such as thorium and uranium isotopes to induce sustained fission or nuclear transmutation in waste radioactive materials. Relevant photo driven and photo-fission reaction cross sections are important for actinides 232Th, 238U and 237Np in the radiotherapy machines energy range of 10-20 MV. In this study we employ passive nuclear track detectors (NTD) to determine fission rates and neutron production rates with the aim to establish the feasibility for gamma and photo-neutron driven subcritical assemblies. To cope with these objectives a 20 MV radiotherapy machine has been employed with a mixed fuel target. Results will support further development for a subcritical assembly employing a thorium containing liquid fuel. It is expected that acquired technological knowledge will contribute to the Venezuelan nuclear energy program.

From isosuperatoms to isosupermolecules: new concepts in cluster science

NASA Astrophysics Data System (ADS)

Liu, Liren; Li, Pai; Yuan, Lan-Feng; Cheng, Longjiu; Yang, Jinlong

2016-06-01

As an extension of the superatom concept, a new concept ``isosuperatom'' is proposed, reflecting the physical phenomenon that a superatom cluster can take multiple geometrical structures with their electronic structures topologically invariant. The icosahedral and cuboctahedral Au135+ units in the Au25(SCH2CH2Ph)18-, Au23(SC6H11)16- and Au24(SAdm)16 nanoclusters are found to be examples of this concept. Furthermore, two isosuperatoms can combine to form a supermolecule. For example, the structure of the {Ag32(DPPE)5(SC6H4CF3)24}2- nanocluster can be understood well in terms of a Ag2212+ supermolecule formed by two Ag138+ isosuperatoms. On the next level of complexity, various combinations of isosuperatoms can lead to supermolecules with different geometrical structures but similar electronic structures, i.e., ``isosupermolecules''. We take two synthesized nanoclusters Au20(PPhpy2)10Cl42+ and Au30S(StBu)18 to illustrate two Au206+ isosupermolecules. The proposed concepts of isosuperatom and isosupermolecule significantly enrich the superatom concept, give a new framework for understanding a wide range of nanoclusters, and open a new door for designing assembled materials.As an extension of the superatom concept, a new concept ``isosuperatom'' is proposed, reflecting the physical phenomenon that a superatom cluster can take multiple geometrical structures with their electronic structures topologically invariant. The icosahedral and cuboctahedral Au135+ units in the Au25(SCH2CH2Ph)18-, Au23(SC6H11)16- and Au24(SAdm)16 nanoclusters are found to be examples of this concept. Furthermore, two isosuperatoms can combine to form a supermolecule. For example, the structure of the {Ag32(DPPE)5(SC6H4CF3)24}2- nanocluster can be understood well in terms of a Ag2212+ supermolecule formed by two Ag138+ isosuperatoms. On the next level of complexity, various combinations of isosuperatoms can lead to supermolecules with different geometrical structures but similar electronic structures, i.e., ``isosupermolecules''. We take two synthesized nanoclusters Au20(PPhpy2)10Cl42+ and Au30S(StBu)18 to illustrate two Au206+ isosupermolecules. The proposed concepts of isosuperatom and isosupermolecule significantly enrich the superatom concept, give a new framework for understanding a wide range of nanoclusters, and open a new door for designing assembled materials. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01998f

Synthesis and Self-Assembly of the "Tennis Ball" Dimer and Subsequent Encapsulation of Methane. An Advanced Organic Chemistry Laboratory Experiment

NASA Astrophysics Data System (ADS)

Hof, Fraser; Palmer, Liam C.; Rebek, Julius, Jr.

2001-11-01

While important to the biological and materials sciences, noncovalent interactions, self-folding, and self-assembly often receive little discussion in the undergraduate chemistry curriculum. The synthesis and NMR characterization of a molecular "tennis ball" in an advanced undergraduate organic chemistry laboratory is a simple and effective way to introduce the relevance of these concepts. In appropriate solvents, the monomer dimerizes through a seam of eight hydrogen bonds with encapsulation of a guest molecule and symmetry reminiscent of a tennis ball. The entire experiment can be completed in three lab periods, however large-scale synthetic preparation of the starting monomer by a teaching assistant would reduce the laboratory to a single lab period for NMR studies.

Space operations center: Shuttle interaction study extension, executive summary

NASA Technical Reports Server (NTRS)

1982-01-01

The Space Operations Center (SOC) is conceived as a permanent facility in low Earth orbit incorporating capabilities for space systems construction; space vehicle assembly, launching, recovery and servicing; and the servicing of co-orbiting satellites. The Shuttle Transportation System is an integral element of the SOC concept. It will transport the various elements of the SOC into space and support the assembly operation. Subsequently, it will regularly service the SOC with crew rotations, crew supplies, construction materials, construction equipment and components, space vehicle elements, and propellants and spare parts. The implications to the SOC as a consequence of the Shuttle supporting operations are analyzed. Programmatic influences associated with propellant deliveries, spacecraft servicing, and total shuttle flight operations are addressed.

Design colloidal particle morphology and self-assembly for coating applications

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

Jiang, Shan; Van Dyk, Antony; Maurice, Alvin

The progressive replacement of organic solvent-based coatings by waterborne latex polymer coatings has substantially renovated the coating industry, and generated huge environmental and health benefits. Today, on top of the continuing demand for higher performance and lower costs, the coating industry faces tighter regulation and higher sustainability standards. In addition, the new waterborne coatings have created unique opportunities and challenges in terms of fundamental understanding and research development. To address these challenges, polymer latex binders with diverse particle morphologies have been developed to improve coating performance. Furthermore, colloidal self-assembly has been utilized to help manufacturers make better paint with lessmore » cost. In this report, we review the recent progress in both fundamental study and industrial application in the context of developing new generation architectural coating materials. We introduce the basic concepts in coating materials and showcase several key technologies that have been implemented to improve coating performance. As a result, these technologies also represent the most important considerations in architectural coating design.« less

Halogen-bonding-triggered supramolecular gel formation

NASA Astrophysics Data System (ADS)

Meazza, Lorenzo; Foster, Jonathan A.; Fucke, Katharina; Metrangolo, Pierangelo; Resnati, Giuseppe; Steed, Jonathan W.

2013-01-01

Supramolecular gels are topical soft materials involving the reversible formation of fibrous aggregates using non-covalent interactions. There is significant interest in controlling the properties of such materials by the formation of multicomponent systems, which exhibit non-additive properties emerging from interaction of the components. The use of hydrogen bonding to assemble supramolecular gels in organic solvents is well established. In contrast, the use of halogen bonding to trigger supramolecular gel formation in a two-component gel (‘co-gel’) is essentially unexplored, and forms the basis for this study. Here, we show that halogen bonding between a pyridyl substituent in a bis(pyridyl urea) and 1,4-diiodotetrafluorobenzene brings about gelation, even in polar media such as aqueous methanol and aqueous dimethylsulfoxide. This demonstrates that halogen bonding is sufficiently strong to interfere with competing gel-inhibitory interactions and create a ‘tipping point’ in gel assembly. Using this concept, we have prepared a halogen bond donor bis(urea) gelator that forms co-gels with halogen bond acceptors.

Synthetic biology engineering of biofilms as nanomaterials factories.

PubMed

Nguyen, Peter Q

2017-06-15

Bottom-up fabrication of nanoscale materials has been a significant focus in materials science for expanding our technological frontiers. This assembly concept, however, is old news to biology - all living organisms fabricate themselves using bottom-up principles through a vast self-organizing system of incredibly complex biomolecules, a marvelous dynamic that we are still attempting to unravel. Can we use what we have gleaned from biology thus far to illuminate alternative strategies for designer nanomaterial manufacturing? In the present review article, new synthetic biology efforts toward using bacterial biofilms as platforms for the synthesis and secretion of programmable nanomaterials are described. Particular focus is given to self-assembling functional amyloids found in bacterial biofilms as re-engineerable modular nanomolecular components. Potential applications and existing challenges for this technology are also explored. This novel approach for repurposing biofilm systems will enable future technologies for using engineered living systems to grow artificial nanomaterials. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

Design colloidal particle morphology and self-assembly for coating applications

DOE PAGES

Jiang, Shan; Van Dyk, Antony; Maurice, Alvin; ...

2017-05-04

The progressive replacement of organic solvent-based coatings by waterborne latex polymer coatings has substantially renovated the coating industry, and generated huge environmental and health benefits. Today, on top of the continuing demand for higher performance and lower costs, the coating industry faces tighter regulation and higher sustainability standards. In addition, the new waterborne coatings have created unique opportunities and challenges in terms of fundamental understanding and research development. To address these challenges, polymer latex binders with diverse particle morphologies have been developed to improve coating performance. Furthermore, colloidal self-assembly has been utilized to help manufacturers make better paint with lessmore » cost. In this report, we review the recent progress in both fundamental study and industrial application in the context of developing new generation architectural coating materials. We introduce the basic concepts in coating materials and showcase several key technologies that have been implemented to improve coating performance. As a result, these technologies also represent the most important considerations in architectural coating design.« less

Solar central receiver heliostat reflector assembly

DOEpatents

Horton, Richard H.; Zdeb, John J.

1980-01-01

A heliostat reflector assembly for a solar central receiver system comprises a light-weight, readily assemblable frame which supports a sheet of stretchable reflective material and includes mechanism for selectively applying tension to and positioning the sheet to stretch it to optical flatness. The frame is mounted on and supported by a pipe pedestal assembly that, in turn, is installed in the ground. The frame is controllably driven in a predetermined way by a light-weight drive system so as to be angularly adjustable in both elevation and azimuth to track the sun and efficiently continuously reflect the sun's rays to a focal zone, i.e. central receiver, which forms part of a solar energy utilization system, such as a solar energy fueled electrical power generation system. The frame may include a built-in system for testing for optical flatness of the reflector. The preferable geometric configuration of the reflector is octagonal; however, it may be other shapes, such as hexagonal, pentagonal or square. Several different embodiments of means for tensioning and positioning the reflector to achieve optical flatness are disclosed. The reflector assembly is based on the stretch frame concept which provides an extremely light-weight, simple, low-cost reflector assembly that may be driven for positioning and tracking by a light-weight, inexpensive drive system.

Novel Self-Assembling Amino Acid-Derived Block Copolymer with Changeable Polymer Backbone Structure.

PubMed

Koga, Tomoyuki; Aso, Eri; Higashi, Nobuyuki

2016-11-29

Block copolymers have attracted much attention as potentially interesting building blocks for the development of novel nanostructured materials in recent years. Herein, we report a new type of self-assembling block copolymer with changeable polymer backbone structure, poly(Fmoc-Ser) ester -b-PSt, which was synthesized by combining the polycondensation of 9-fluorenylmethoxycarbonyl-serine (Fmoc-Ser) with the reversible addition-fragmentation chain transfer (RAFT) polymerization of styrene (St). This block copolymer showed the direct conversion of the backbone structure from polyester to polypeptide through a multi O,N-acyl migration triggered by base-induced deprotection of Fmoc groups in organic solvent. Such polymer-to-polymer conversion was found to occur quantitatively without decrease in degree of polymerization and to cause a drastic change in self-assembling property of the block copolymer. On the basis of several morphological analyses using FTIR spectroscopy, atomic force, and transmission and scanning electron microscopies, the resulting peptide block copolymer was found to self-assemble into a vesicle-like hollow nanosphere with relatively uniform diameter of ca. 300 nm in toluene. In this case, the peptide block generated from polyester formed β-sheet structure, indicating the self-assembly via peptide-guided route. We believe the findings presented in this study offer a new concept for the development of self-assembling block copolymer system.

National Launch System: Structures and materials

NASA Technical Reports Server (NTRS)

Bunting, Jack O.

1993-01-01

The National Launch System provides an opportunity to realize the potential of Al-Li. Advanced structures can reduce weights by 5-40 percent as well as relax propulsion system performance specifications and reduce requirements for labor and materials. The effect on costs will be substantial. Advanced assembly and process control technologies also offer the potential for greatly reduced labor during the manufacturing and inspection processes. Current practices are very labor-intensive and, as a result, labor costs far outweigh material costs for operational space transportation systems. The technological readiness of new structural materials depends on their commercial availability, producibility and materials properties. Martin Marietta is vigorously pursuing the development of its Weldalite 049 Al-Li alloys in each of these areas. Martin Marietta is also preparing to test an automated work cell concept that it has developed using discrete event simulation.

Autonomous Assembly of Modular Structures in Space and on Extraterrestrial Locations

NASA Technical Reports Server (NTRS)

Alhorn, Dean C.

2005-01-01

The fulfillment of the new US. National Vision for Space Exploration requires many new enabling technologies to accomplish the goal of utilizing space for commercial activities and for returning humans to the moon and extraterrestrial environments. Traditionally, flight structures are manufactured as complete systems and require humans to complete the integration and assembly in orbit. These structures are bulky and require the use of heavy launch vehicles to send the units to the desired location, e.g. International Space Station (ISS). This method requires a high degree of safety, numerous space walks and significant cost for the humans to perform the assembly in orbit. For example, for assembly and maintenance of the ISS, 52 Extravehicular Activities (EVA's) have been performed so far with a total EVA time of approximately 322 hours. Sixteen (16) shuttle flights haw been to the ISS to perform these activities with an approximate cost of $450M per mission. For future space missions, costs have to be reduced to reasonably achieve the exploration goals. One concept that has been proposed is the autonomous assembly of space structures. This concept is an affordable, reliable solution to in-space and extraterrestrial assembly operations. Assembly is autonomously performed when two components containing onboard electronics join after recognizing that the joint is appropriate and in the precise position and orientation required for assembly. The mechanism only activates when the specifications are correct and m a nominal range. After assembly, local sensors and electronics monitor the integrity of the joint for feedback to a master controller. To achieve this concept will require a shift in the methods for designing space structures. In addition, innovative techniques will be required to perform the assembly autonomously. Monitoring of the assembled joint will be necessary for safety and structural integrity. If a very large structure is to be assembled in orbit, then the number of integrity sensors will be significant. Thus simple, low cost sensors are integral to the success of this concept. This paper will address these issues and will propose a novel concept for assembling space structures autonomously. The paper will present Several autonomous assembly methods. Core technologies required to achieve in space assembly will be discussed and novel techniques for communicating, sensing, docking and assembly will be detailed. These core technologies are critical to the goal of utilizing space in a cost efficient and safe manner. Finally, these technologies can also be applied to other systems both on earth and extraterrestrial environments.

Technology for large space systems: A bibliography with indexes (supplement 22)

NASA Technical Reports Server (NTRS)

1990-01-01

This bibliography lists 1077 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System between July 1, 1989 and December 31, 1989. Its purpose is to provide helpful information to the researcher or manager engaged in the development of technologies related to large space systems. Subject areas include mission and program definition, design techniques, structural and thermal analysis, structural dynamics and control systems, electronics, advanced materials, assembly concepts, and propulsion.

Initial Validation of Robotic Operations for In-Space Assembly of a Large Solar Electric Propulsion Transport Vehicle

NASA Technical Reports Server (NTRS)

Komendera, Erik E.; Dorsey, John T.

2017-01-01

Developing a capability for the assembly of large space structures has the potential to increase the capabilities and performance of future space missions and spacecraft while reducing their cost. One such application is a megawatt-class solar electric propulsion (SEP) tug, representing a critical transportation ability for the NASA lunar, Mars, and solar system exploration missions. A series of robotic assembly experiments were recently completed at Langley Research Center (LaRC) that demonstrate most of the assembly steps for the SEP tug concept. The assembly experiments used a core set of robotic capabilities: long-reach manipulation and dexterous manipulation. This paper describes cross-cutting capabilities and technologies for in-space assembly (ISA), applies the ISA approach to a SEP tug, describes the design and development of two assembly demonstration concepts, and summarizes results of two sets of assembly experiments that validate the SEP tug assembly steps.

Design and analysis of sustainable computer mouse using design for disassembly methodology

NASA Astrophysics Data System (ADS)

Roni Sahroni, Taufik; Fitri Sukarman, Ahmad; Agung Mahardini, Karunia

2017-12-01

This paper presents the design and analysis of computer mouse using Design for Disassembly methodology. Basically, the existing computer mouse model consist a number of unnecessary part that cause the assembly and disassembly time in production. The objective of this project is to design a new computer mouse based on Design for Disassembly (DFD) methodology. The main methodology of this paper was proposed from sketch generation, concept selection, and concept scoring. Based on the design screening, design concept B was selected for further analysis. New design of computer mouse is proposed using fastening system. Furthermore, three materials of ABS, Polycarbonate, and PE high density were prepared to determine the environmental impact category. Sustainable analysis was conducted using software SolidWorks. As a result, PE High Density gives the lowers amount in the environmental category with great maximum stress value.

Beyond the Periodic Table of Elements: The Role of Superatoms.

PubMed

Jena, Puru

2013-05-02

Atomic clusters composed of homo or heteroatomic species constitute an intermediate phase of matter where every atom counts and whose properties depend on their size, shape, composition, and charge. If specific clusters mimicking the chemistry of atoms can be produced, they can be thought of as man-made superatoms forming the building blocks of a new three-dimensional periodic table. Novel materials with tailored properties can then be synthesized by assembling these superatoms. This invited Perspective presents a brief summary of the pioneering works that led to this concept, and highlights the recent breakthroughs that hold promise for a new era in materials science.

A shuttle and space station manipulator system for assembly, docking, maintenance, cargo handling and spacecraft retrieval (preliminary design). Volume 3: Concept analysis. Part 1: Technical

NASA Technical Reports Server (NTRS)

1972-01-01

Information backing up the key features of the manipulator system concept and detailed technical information on the subsystems are presented. Space station assembly and shuttle cargo handling tasks are emphasized in the concept analysis because they involve shuttle berthing, transferring the manipulator boom between shuttle and station, station assembly, and cargo handling. Emphasis is also placed on maximizing commonality in the system areas of manipulator booms, general purpose end effectors, control and display, data processing, telemetry, dedicated computers, and control station design.

Quantitative Ultrasonic Evaluation of Mechanical Properties of Engineering Materials

NASA Technical Reports Server (NTRS)

Vary, A.

1978-01-01

Progress in the application of ultrasonic techniques to nondestructive measurement of mechanical strength of engineering materials is reviewed. A dormant concept in nondestructive evaluation (NDE) is invoked. The availability of ultrasonic methods that can be applied to actual parts to assess their potential susceptibility to failure under design conditions is discussed. It was shown that ultrasonic methods yield measurements of elastic moduli, microstructure, hardness, fracture toughness, tensile strength, yield strength, and shear strength for a wide range of materials (including many types of metals, ceramics, and fiber composites). It was also indicated that although most of these methods were shown feasible in laboratory studies, more work is needed before they can be used on actual parts in processing, assembly, inspection, and maintenance lines.

Biocatalytic Self-Assembly on Magnetic Nanoparticles.

PubMed

Conte, Maria P; Sahoo, Jugal Kishore; Abul-Haija, Yousef M; Lau, K H Aaron; Ulijn, Rein V

2018-01-24

Combining (bio)catalysis and molecular self-assembly provides an effective approach for the production and processing of self-assembled materials by exploiting catalysis to direct the assembly kinetics and hence controlling the formation of ordered nanostructures. Applications of (bio)catalytic self-assembly in biologically interfacing systems and in nanofabrication have recently been reported. Inspired by self-assembly in biological cells, efforts to confine catalysts on flat or patterned surfaces to exert spatial control over molecular gelator generation and nanostructure self-assembly have also emerged. Building on our previous work in the area, we demonstrate in this report the use of enzymes immobilized onto magnetic nanoparticles (NPs) to spatially localize the initiation of peptide self-assembly into nanofibers around NPs. The concept is generalized for both an equilibrium biocatalytic system that forms stable hydrogels and a nonequilibrium system that normally has a preset lifetime. Characterization of the hydrogels shows that self-assembly occurs at the site of enzyme immobilization on the NPs to give rise to gels with a "hub-and-spoke" morphology, where the nanofibers are linked through the enzyme-NP conjugates. This NP-controlled arrangement of self-assembled nanofibers enables both remarkable enhancements in the shear strength of hydrogel systems and a dramatic extension of the hydrogel stability in the nonequilibrium system. We are also able to show that the use of magnetic NPs enables the external control of both the formation of the hydrogel and its overall structure by application of an external magnetic field. We anticipate that the enhanced properties and stimuli-responsiveness of our NP-enzyme system will have applications ranging from nanomaterial fabrication to biomaterials and biosensing.

Space Assembly, Maintenance and Servicing Study. Volume 4: Concept Development Plan.

DTIC Science & Technology

1986-01-01

development of the concept development program (COP) plan: 1) Develop the CDP candidate work sheets 2) Categorize by application 3) Prioritize by... categorized under the ORU change-out section of this report, the large system assembly area will attempt to cover the EVA aspects of SAMS not discussed...space assemblies involve the evolvement of technologies related to multilevel orbital operating platforms on which both individual and cooperative

Space construction system analysis. Part 2: Space construction experiments concepts

NASA Technical Reports Server (NTRS)

Boddy, J. A.; Wiley, L. F.; Gimlich, G. W.; Greenberg, H. S.; Hart, R. J.; Lefever, A. E.; Lillenas, A. N.; Totah, R. S.

1980-01-01

Technology areas in the orbital assembly of large space structures are addressed. The areas included structures, remotely operated assembly techniques, and control and stabilization. Various large space structure design concepts are reviewed and their construction procedures and requirements are identified.

DNA-controlled dynamic colloidal nanoparticle systems for mediating cellular interaction

NASA Astrophysics Data System (ADS)

Ohta, Seiichi; Glancy, Dylan; Chan, Warren C. W.

2016-02-01

Precise control of biosystems requires development of materials that can dynamically change physicochemical properties. Inspired by the ability of proteins to alter their conformation to mediate function, we explored the use of DNA as molecular keys to assemble and transform colloidal nanoparticle systems. The systems consist of a core nanoparticle surrounded by small satellites, the conformation of which can be transformed in response to DNA via a toe-hold displacement mechanism. The conformational changes can alter the optical properties and biological interactions of the assembled nanosystem. Photoluminescent signal is altered by changes in fluorophore-modified particle distance, whereas cellular targeting efficiency is increased 2.5 times by changing the surface display of targeting ligands. These concepts provide strategies for engineering dynamic nanotechnology systems for navigating complex biological environments.

Heteroleptic metallosupramolecular racks, rectangles, and trigonal prisms: stoichiometry-controlled reversible interconversion.

PubMed

Neogi, Subhadip; Lorenz, Yvonne; Engeser, Marianne; Samanta, Debabrata; Schmittel, Michael

2013-06-17

A simple approach toward preparation of heteroleptic two-dimensional (2D) rectangles and three-dimensional (3D) triangular prisms is described utilizing the HETPYP (HETeroleptic PYridyl and Phenanthroline metal complexes) concept. By mixing metal-loaded linear bisphenanthrolines of varying lengths with diverse (multi)pyridine (py) ligands in a proper ratio, six different self-assembled architectures arise cleanly and spontaneously in the absence of any template. They are characterized by (1)H and DOSY NMR, ESI-FT-ICR mass spectrometry as well as by Job plots and UV-vis titrations. Density functional theory (DFT) computations provide information about each structure. A stoichiometry-controlled supramolecule-to-supramolecule interconversion based on the relative amounts of metal bisphenanthroline and bipyridine forces the rectangular assembly to reorganize to a rack architecture and back to the rectangle, as clearly supported by variable temperature and DOSY NMR as well as dynamic light scattering data. The highly dynamic nature of the assemblies represents a promising starting point for constitutional dynamic materials.

Preliminary SP-100/Stirling Heat Exchanger Designs

NASA Astrophysics Data System (ADS)

Schmitz, Paul; Tower, Leonard; Dawson, Ronald; Blue, Brain; Dunn, Pat

1994-07-01

Analytic modeling of several heat exchanger concepts to couple the SP-100 nuclear reactor primary lithium loop and the Space Stirling Power Convertor(SSPC)was performed. Four 25 kWe SSPC's are used to produce the required 100 kW of electrical power. This design work focused on the interface between a single SSPC and the primary lithium loop. Manifolding to separate and collect the four channel flow was not modeled. This work modeled two separate types of heat exchanger interfaces (conductive coupling and radiative coupling) to explore their relative advantages and disadvantages. The minimum mass design of the conductively coupled concepts was 18 kg or 0.73 kg/kWe for a single 25 kWe convertor. The minimum mass radiatively coupled concept was 41 kg or 1.64 kg/kWe. The direct conduction heat exchanger provides a lighter weight system because of its ability to operate the Stirling convertor evaporator at higher heat fluxes than those attainable by the radiatively coupled systems. Additionally the conductively coupled concepts had relatively small volumes and provide potentially simpler assembly. Their disadvantages were the tight tolerances and material joining problems associated with this refractory to superalloy interface. The advantages of the radiatively coupled designs were the minimal material interface problems.

Preliminary SP-100/Stirling heat exchanger designs

NASA Astrophysics Data System (ADS)

Schmitz, Paul; Tower, Leonard; Dawson, Ronald; Blue, Brian; Dunn, Pat

1993-12-01

Analytic modeling of several heat exchanger concepts to couple the SP-100 nuclear reactor primary lithium loop and the Space Stirling Power Convertor (SSPC) was performed. Four 25 kWe SSPC's are used to produce the required 100 kW of electrical power. This design work focused on the interface between a single SSPC and the primary lithium loop. Manifolding to separate and collect the four channel flow was not modeled. This work modeled two separate types of heat exchanger interfaces (conductive coupling and radiative coupling) to explore their relative advantages and disadvantages. The minimum mass design of the conductively coupled concepts was 18 kg or 0.73 kg/kWe for a single 25 kWe convertor. The minimum mass radiatively coupled concept was 41 kg or 1.64 kg/kWe. The direct conduction heat exchanger provides a lighter weight system because of its ability to operate the Stirling convertor evaporator at higher heat fluxes than those attainable by the radiatively coupled systems. Additionally the conductively coupled concepts had relatively small volumes and provide potentially simpler assembly. Their disadvantages were the tight tolerances and material joining problems associated with this refractory to superalloy interface. The advantages of the radiatively coupled designs were the minimal material interface problems.

Preliminary SP-100/Stirling heat exchanger designs

NASA Technical Reports Server (NTRS)

Schmitz, Paul; Tower, Leonard; Dawson, Ronald; Blue, Brian; Dunn, Pat

1993-01-01

Analytic modeling of several heat exchanger concepts to couple the SP-100 nuclear reactor primary lithium loop and the Space Stirling Power Convertor (SSPC) was performed. Four 25 kWe SSPC's are used to produce the required 100 kW of electrical power. This design work focused on the interface between a single SSPC and the primary lithium loop. Manifolding to separate and collect the four channel flow was not modeled. This work modeled two separate types of heat exchanger interfaces (conductive coupling and radiative coupling) to explore their relative advantages and disadvantages. The minimum mass design of the conductively coupled concepts was 18 kg or 0.73 kg/kWe for a single 25 kWe convertor. The minimum mass radiatively coupled concept was 41 kg or 1.64 kg/kWe. The direct conduction heat exchanger provides a lighter weight system because of its ability to operate the Stirling convertor evaporator at higher heat fluxes than those attainable by the radiatively coupled systems. Additionally the conductively coupled concepts had relatively small volumes and provide potentially simpler assembly. Their disadvantages were the tight tolerances and material joining problems associated with this refractory to superalloy interface. The advantages of the radiatively coupled designs were the minimal material interface problems.

Interim status report on lead-cooled fast reactor (LFR) research and development.

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

Tzanos, C. P.; Sienicki, J. J.; Moisseytsev, A.

2008-03-31

This report discusses the status of Lead-Cooled Fast Reactor (LFR) research and development carried out during the first half of FY 2008 under the U.S. Department of Energy Generation IV Nuclear Energy Systems Initiative. Lead-Cooled Fast Reactor research and development has recently been transferred from Generation IV to the Reactor Campaign of the Global Nuclear Energy Partnership (GNEP). Another status report shall be issued at the end of FY 2008 covering all of the LFR activities carried out in FY 2008 for both Generation IV and GNEP. The focus of research and development in FY 2008 is an initial investigationmore » of a concept for a LFR Advanced Recycling Reactor (ARR) Technology Pilot Plant (TPP)/demonstration test reactor (demo) incorporating features and operating conditions of the European Lead-cooled SYstem (ELSY) {approx} 600 MWe lead (Pb)-cooled LFR preconceptual design for the transmutation of waste and central station power generation, and which would enable irradiation testing of advanced fuels and structural materials. Initial scoping core concept development analyses have been carried out for a 100 MWt core composed of sixteen open-lattice 20 by 20 fuel assemblies largely similar to those of the ELSY preconceptual fuel assembly design incorporating fuel pins with mixed oxide (MOX) fuel, central control rods in each fuel assembly, and cooled with Pb coolant. For a cycle length of three years, the core is calculated to have a conversion ratio of 0.79, an average discharge burnup of 108 MWd/kg of heavy metal, and a burnup reactivity swing of about 13 dollars. With a control rod in each fuel assembly, the reactivity worth of an individual rod would need to be significantly greater than one dollar which is undesirable for postulated rod withdrawal reactivity insertion events. A peak neutron fast flux of 2.0 x 10{sup 15} (n/cm{sup 2}-s) is calculated. For comparison, the 400 MWt Fast Flux Test Facility (FFTF) achieved a peak neutron fast flux of 7.2 x 10{sup 15} (n/cm{sup 2}-s) and the initially 563 MWt PHENIX reactor attained 2.0 x 10{sup 15} (n/cm{sup 2}-s) before one of three intermediate cooling loops was shut down due to concerns about potential steam generator tube failures. The calculations do not assume a test assembly location for advanced fuels and materials irradiation in place of a fuel assembly (e.g., at the center of the core); the calculations have not examined whether it would be feasible to replace the central assembly by a test assembly location. However, having only fifteen driver assemblies implies a significant effect due to perturbations introduced by the test assembly. The peak neutron fast flux is low compared with the fast fluxes previously achieved in FFTF and PHENIX. Furthermore, the peak neutron fluence is only about half of the limiting value (4 x 10{sup 23} n/cm{sup 2}) typically used for ferritic steels. The results thus suggest that a larger power level (e.g., 400 MWt) and a larger core would be better for a TPP based upon the ELSY fuel assembly design and which can also perform irradiation testing of advanced fuels and materials. In particular, a core having a higher power level and larger dimensions would achieve a suitable average discharge burnup, peak fast flux, peak fluence, and would support the inclusion of one or more test assembly locations. Participation in the Generation IV International Forum Provisional System Steering Committee for the LFR is being maintained throughout FY 2008. Results from the analysis of samples previously exposed to flowing lead-bismuth eutectic (LBE) in the DELTA loop are summarized and a model for the oxidation/corrosion kinetics of steels in heavy liquid metal coolants was applied to systematically compare the calculated long-term (i.e., following several years of growth) oxide layer thicknesses of several steels.« less

Analytical and experimental investigation of aircraft metal structures reinforced with filamentary composites. Phase 1: Concept development and feasibility

NASA Technical Reports Server (NTRS)

Oken, S.; June, R. R.

1971-01-01

The analytical and experimental investigations are described in the first phase of a program to establish the feasibility of reinforcing metal aircraft structures with advanced filamentary composites. The interactions resulting from combining the two types of materials into single assemblies as well as their ability to function structurally were studied. The combinations studied were boron-epoxy reinforced aluminum, boron-epoxy reinforced titanium, and boron-polyimide reinforced titanium. The concepts used unidirectional composites as reinforcement in the primary loading direction and metal for carrying the transverse loads as well as its portion of the primary load. The program established that several realistic concepts could be fabricated, that these concepts could perform to a level that would result in significant weight savings, and that there are means for predicting their capability within a reasonable degree of accuracy. This program also encountered problems related to the application of polyimide systems that resulted in their relatively poor and variable performance.

Microwave power transmission system studies. Volume 3, section 8: Mechanical systems and flight operations

NASA Technical Reports Server (NTRS)

Maynard, O. E.; Brown, W. C.; Edwards, A.; Haley, J. T.; Meltz, G.; Howell, J. M.; Nathan, A.

1975-01-01

The efforts and recommendations associated with preliminary design and concept definition for mechanical systems and flight operations are presented. Technical discussion in the areas of mission analysis, antenna structural concept, configuration analysis, assembly and packaging with associated costs are presented. Technology issues for the control system, structural system, thermal system and assembly including cost and man's role in assembly and maintenance are identified. Background and desired outputs for future efforts are discussed.

Method of making hermetic seals for hermetic terminal assemblies

DOEpatents

Hsu, John S.; Marlino, Laura D.; Ayers, Curtis W.

2010-04-13

This invention teaches methods of making a hermetic terminal assembly comprising the steps of: inserting temporary stops, shims and jigs on the bottom face of a terminal assembly thereby blocking assembly core open passageways; mounting the terminal assembly inside a vacuum chamber using a temporary assembly perimeter seal and flange or threaded assembly interfaces; mixing a seal admixture and hardener in a mixer conveyor to form a polymer seal material; conveying the polymer seal material into a polymer reservoir; feeding the polymer seal material from the reservoir through a polymer outlet valve and at least one polymer outlet tube into the terminal assembly core thereby filling interstitial spaces in the core adjacent to service conduits, temporary stop, and the terminal assembly casing; drying the polymer seal material at room temperature thereby hermetically sealing the core of the terminal assembly; removing the terminal assembly from the vacuum chamber, and; removing the temporary stops, shims.

Multi-pack Disposal Concepts for Spent Fuel (Rev. 0)

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

Hadgu, Teklu; Hardin, Ernest; Matteo, Edward N.

2015-12-01

At the initiation of the Used Fuel Disposition (UFD) R&D campaign, international geologic disposal programs and past work in the U.S. were surveyed to identify viable disposal concepts for crystalline, clay/shale, and salt host media (Hardin et al., 2012). Concepts for disposal of commercial spent nuclear fuel (SNF) and high-level waste (HLW) from reprocessing are relatively advanced in countries such as Finland, France, and Sweden. The UFD work quickly showed that these international concepts are all “enclosed,” whereby waste packages are emplaced in direct or close contact with natural or engineered materials . Alternative “open” modes (emplacement tunnels are keptmore » open after emplacement for extended ventilation) have been limited to the Yucca Mountain License Application Design (CRWMS M&O, 1999). Thermal analysis showed that, if “enclosed” concepts are constrained by peak package/buffer temperature, waste package capacity is limited to 4 PWR assemblies (or 9-BWR) in all media except salt. This information motivated separate studies: 1) extend the peak temperature tolerance of backfill materials, which is ongoing; and 2) develop small canisters (up to 4-PWR size) that can be grouped in larger multi-pack units for convenience of storage, transportation, and possibly disposal (should the disposal concept permit larger packages). A recent result from the second line of investigation is the Task Order 18 report: Generic Design for Small Standardized Transportation, Aging and Disposal Canister Systems (EnergySolution, 2015). This report identifies disposal concepts for the small canisters (4-PWR size) drawing heavily on previous work, and for the multi-pack (16-PWR or 36-BWR).« less

Multi-Pack Disposal Concepts for Spent Fuel (Revision 1)

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

Hardin, Ernest; Matteo, Edward N.; Hadgu, Teklu

2016-01-01

At the initiation of the Used Fuel Disposition (UFD) R&D campaign, international geologic disposal programs and past work in the U.S. were surveyed to identify viable disposal concepts for crystalline, clay/shale, and salt host media. Concepts for disposal of commercial spent nuclear fuel (SNF) and high-level waste (HLW) from reprocessing are relatively advanced in countries such as Finland, France, and Sweden. The UFD work quickly showed that these international concepts are all “enclosed,” whereby waste packages are emplaced in direct or close contact with natural or engineered materials . Alternative “open” modes (emplacement tunnels are kept open after emplacement formore » extended ventilation) have been limited to the Yucca Mountain License Application Design. Thermal analysis showed that if “enclosed” concepts are constrained by peak package/buffer temperature, that waste package capacity is limited to 4 PWR assemblies (or 9 BWR) in all media except salt. This information motivated separate studies: 1) extend the peak temperature tolerance of backfill materials, which is ongoing; and 2) develop small canisters (up to 4-PWR size) that can be grouped in larger multi-pack units for convenience of storage, transportation, and possibly disposal (should the disposal concept permit larger packages). A recent result from the second line of investigation is the Task Order 18 report: Generic Design for Small Standardized Transportation, Aging and Disposal Canister Systems. This report identifies disposal concepts for the small canisters (4-PWR size) drawing heavily on previous work, and for the multi-pack (16-PWR or 36-BWR).« less

NanoShuttles: Harnessing Motor Proteins to Transport Cargo in Synthetic Environments

NASA Astrophysics Data System (ADS)

Vogel, V.; Hess, H.

Motors have become a crucial commodity in our daily lives, from transportation to driving conveyor belts that enable the sequential assembly of cars and other industrial machines. For the sequential assembly of building blocks at the nanoscale that would not assemble spontaneously into larger functional systems, however, active transport systems are not yet available. In contrast, cells have evolved sophisticated molecular machinery that drives movement and active transport. Driven by the conversion of chemical into mechanical energy, namely through hydrolysis of the biological fuel ATP, molecular motors enable cells to operate far away from equilibrium by transporting organelles and molecules to designated locations within the cell, often against concentration gradients. Inspired by the biological concept of active transport, major efforts are underway to learn how to build nanoscale transport systems that are driven by molecular motors. Emerging engineering principles are discussed of how to build tracks and junctions to guide such nanoshuttles, how to load them with cargo and control their speed, how to use active transport to assemble mesoscopic structures that would otherwise not assemble spontaneously and what polymeric materials to choose to integrate motors into MEMS and other biohybrid devices. Finally, two applications that exploit the physical properties of microtubules are discussed, surface imaging by a swarm of microtubules and a self-assembled picoNewton force meter to probe receptor-ligand interactions.

Lightweight Composite Materials for Heavy Duty Vehicles

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

Pruez, Jacky; Shoukry, Samir; Williams, Gergis

The main objective of this project is to develop, analyze and validate data, methodologies and tools that support widespread applications of automotive lightweighting technologies. Two underlying principles are guiding the research efforts towards this objective: • Seamless integration between the lightweight materials selected for certain vehicle systems, cost-effective methods for their design and manufacturing, and practical means to enhance their durability while reducing their Life-Cycle-Costs (LCC). • Smooth migration of the experience and findings accumulated so far at WVU in the areas of designing with lightweight materials, innovative joining concepts and durability predictions, from applications to the area of weightmore » savings for heavy vehicle systems and hydrogen storage tanks, to lightweighting applications of selected systems or assemblies in light–duty vehicles.« less

Carbon composites in space vehicle structures

NASA Technical Reports Server (NTRS)

Mayer, N. J.

1974-01-01

Recent developments in the technology of carbon or graphite filaments now provide the designer with greatly improved materials offering high specific strength and modulus. Besides these advantages are properties which are distinctly useful for space applications and which provide feasibility for missions not obtainable by other means. Current applications include major and secondary structures of communications satellites. A number of R & D projects are exploring carbon-fiber application to rocket engine motor cases, advanced antenna systems, and space shuttle components. Future system studies are being made, based on the successful application of carbon fibers for orbiting space telescope assemblies, orbital transfer vehicles, and very large deployable energy generation systems. Continued technology development is needed in analysis, material standards, and advanced structural concepts to exploit the full potential of carbon filaments in composite materials.

Ergonomic risk assessment with DesignCheck to evaluate assembly work in different phases of the vehicle development process.

PubMed

Winter, Gabriele; Schaub, Karlheinz G; Großmann, Kay; Laun, Gerhard; Landau, Kurt; Bruder, Ralph

2012-01-01

Occupational hazards exist, if the design of the work situation is not in accordance with ergonomic design principles. At assembly lines ergonomics is applied to the design of work equipment and tasks and to work organisation. The ignoring of ergonomic principles in planning and design of assembly work leads to unfavourable working posture, action force and material handling. Disorders of the musculoskeletal system are of a common occurrence throughout Europe. Musculoskeletal disorders are a challenge against the background of disabled workers. The changes in a worker's capability have to be regarded in the conception of redesigned and new assembly lines. In this way ergonomics becomes progressively more important in planning and design of vehicles: The objective of ergonomic design in different stages of the vehicles development process is to achieve an optimal adaptation of the assembly work to workers. Hence the ergonomic screening tool "Design Check" (DC) was developed to identify ergonomic deficits in workplace layouts. The screening-tool is based on the current ergonomic state of the art in the design of physical work and relevant EU legal requirements. It was tested within a federal German research project at selected work stations at the assembly lines at Dr.-Ing. h.c. F. Porsche AG / Stuttgart. Meanwhile the application of the screening-tool DC is transferred in other parts of the Porsche AG, Stuttgart. It is also realized as an ergonomic standard method to perform assembly work in different phases of the vehicle development process.

Composite fuselage crown panel manufacturing technology

NASA Technical Reports Server (NTRS)

Willden, Kurtis; Metschan, S.; Grant, C.; Brown, T.

1992-01-01

Commercial fuselage structures contain significant challenges in attempting to save manufacturing costs with advanced composite technology. Assembly issues, materials costs, and fabrication of elements with complex geometry are each expected to drive the cost of composite fuselage structure. Key technologies, such as large crown panel fabrication, were pursued for low cost. An intricate bond panel design and manufacturing concept were selected based on the efforts of the Design Build Team. The manufacturing processes selected for the intricate bond design include multiple large panel fabrication with Advanced Tow Placement (ATP) process, innovative cure tooling concepts, resin transfer molding of long fuselage frames, and use of low cost materials forms. The process optimization for final design/manufacturing configuration included factory simulations and hardware demonstrations. These efforts and other optimization tasks were instrumental in reducing costs by 18 pct. and weight by 45 pct. relative to an aluminum baseline. The qualitative and quantitative results of the manufacturing demonstrations were used to assess manufacturing risks and technology readiness.

Composite fuselage crown panel manufacturing technology

NASA Technical Reports Server (NTRS)

Willden, Kurtis; Metschan, S.; Grant, C.; Brown, T.

1992-01-01

Commercial fuselage structures contain significant challenges in attempting to save manufacturing costs with advanced composite technology. Assembly issues, material costs, and fabrication of elements with complex geometry are each expected to drive the cost of composite fuselage structures. Boeing's efforts under the NASA ACT program have pursued key technologies for low-cost, large crown panel fabrication. An intricate bond panel design and manufacturing concepts were selected based on the efforts of the Design Build Team (DBT). The manufacturing processes selected for the intricate bond design include multiple large panel fabrication with the Advanced Tow Placement (ATP) process, innovative cure tooling concepts, resin transfer molding of long fuselage frames, and utilization of low-cost material forms. The process optimization for final design/manufacturing configuration included factory simulations and hardware demonstrations. These efforts and other optimization tasks were instrumental in reducing cost by 18 percent and weight by 45 percent relative to an aluminum baseline. The qualitative and quantitative results of the manufacturing demonstrations were used to assess manufacturing risks and technology readiness.

Mesocrystals in Biominerals and Colloidal Arrays.

PubMed

Bergström, Lennart; Sturm née Rosseeva, Elena V; Salazar-Alvarez, German; Cölfen, Helmut

2015-05-19

Mesocrystals, which originally was a term to designate superstructures of nanocrystals with a common crystallographic orientation, have now evolved to a materials concept. The discovery that many biominerals are mesocrystals generated a large research interest, and it was suggested that mesocrystals result in better mechanical performance and optical properties compared to single crystalline structures. Mesocrystalline biominerals are mainly found in spines or shells, which have to be mechanically optimized for protection or as a load-bearing skeleton. Important examples include red coral and sea urchin spine as well as bones. Mesocrystals can also be formed from purely synthetic components. Biomimetic mineralization and assembly have been used to produce mesocrystals, sometimes with complex hierarchical structures. Important examples include the fluorapatite mesocrystals with gelatin as the structural matrix, and mesocrystalline calcite spicules with impressive strength and flexibility that could be synthesized using silicatein protein fibers as template for calcium carbonate deposition. Self-assembly of nanocrystals can also result in mesocrystals if the nanocrystals have a well-defined size and shape and the assembly conditions are tuned to allow the nanoparticles to align crystallographically. Mesocrystals formed by assembly of monodisperse metallic, semiconducting, and magnetic nanocrystals are a type of colloidal crystal with a well-defined structure on both the atomic and mesoscopic length scale.Mesocrystals typically are hybrid materials between crystalline nanoparticles and interspacing amorphous organic or inorganic layers. This structure allows to combine disparate materials like hard but brittle nanocrystals with a soft and ductile amorphous material, enabling a mechanically optimized structural design as realized in the sea urchin spicule. Furthermore, mesocrystals can combine the properties of individual nanocrystals like the optical quantum size effect, surface plasmon resonance, and size dependent magnetic properties with a mesostructure and morphology tailored for specific applications. Indeed, mesocrystals composed of crystallographically aligned polyhedral or rodlike nanocrystals with anisotropic properties can be materials with strongly directional properties and novel collective emergent properties. An additional advantage of mesocrystals is that they can combine the properties of nanoparticles with a structure on the micro- or macroscale allowing for much easier handling.

How Many Peripheral Solder Joints in a Surface Mounted Design Experience Inelastic Strains?

NASA Astrophysics Data System (ADS)

Suhir, E.; Yi, S.; Ghaffarian, R.

2017-03-01

It has been established that it is the peripheral solder joints that are the most vulnerable in the ball-grid-array (BGA) and column-grid-array (CGA) designs and most often fail. As far as the long-term reliability of a soldered microelectronics assembly as a whole is concerned, it makes a difference, if just one or more peripheral joints experience inelastic strains. It is clear that the low cycle fatigue lifetime of the solder system is inversely proportional to the number of joints that simultaneously experience inelastic strains. A simple and physically meaningful analytical expression (formula) is obtained for the prediction, at the design stage, of the number of such joints, if any, for the given effective thermal expansion (contraction) mismatch of the package and PCB; materials and geometrical characteristics of the package/PCB assembly; package size; and, of course, the level of the yield stress in the solder material. The suggested formula can be used to determine if the inelastic strains in the solder material could be avoided by the proper selection of the above characteristics and, if not, how many peripheral joints are expected to simultaneously experience inelastic strains. The general concept is illustrated by a numerical example carried out for a typical BGA package. The suggested analytical model (formula) is applicable to any soldered microelectronics assembly. The roles of other important factors, such as, e.g., solder material anisotropy, grain size, and their random orientation within a joint, are viewed in this analysis as less important factors than the level of the interfacial stress. The roles of these factors will be accounted for in future work and considered, in addition to the location of the joint, in a more complicated, more sophisticated, and more comprehensive reliability/fatigue model.

In-orbit assembly mission for the Space Solar Power Station

NASA Astrophysics Data System (ADS)

Cheng, ZhengAi; Hou, Xinbin; Zhang, Xinghua; Zhou, Lu; Guo, Jifeng; Song, Chunlin

2016-12-01

The Space Solar Power Station (SSPS) is a large spacecraft that utilizes solar power in space to supply power to an electric grid on Earth. A large symmetrical integrated concept has been proposed by the China Academy of Space Technology (CAST). Considering its large scale, the SSPS requires a modular design and unitized general interfaces that would be assembled in orbit. Facilities system supporting assembly procedures, which include a Reusable Heavy Lift Launch Vehicle, orbital transfer and space robots, is introduced. An integrated assembly scheme utilizing space robots to realize this platform SSPS concept is presented. This paper tried to give a preliminary discussion about the minimized time and energy cost of the assembly mission under best sequence and route This optimized assembly mission planning allows the SSPS to be built in orbit rapidly, effectively and reliably.

Self-assembly concepts for multicompartment nanostructures

NASA Astrophysics Data System (ADS)

Gröschel, André H.; Müller, Axel H. E.

2015-07-01

Compartmentalization is ubiquitous to many biological and artificial systems, be it for the separate storage of incompatible matter or to isolate transport processes. Advancements in the synthesis of sequential block copolymers offer a variety of tools to replicate natural design principles with tailor-made soft matter for the precise spatial separation of functionalities on multiple length scales. Here, we review recent trends in the self-assembly of amphiphilic block copolymers to multicompartment nanostructures (MCNs) under (semi-)dilute conditions, with special emphasis on ABC triblock terpolymers. The intrinsic immiscibility of connected blocks induces short-range repulsion into discrete nano-domains stabilized by a third, soluble block or molecular additive. Polymer blocks can be synthesized from an arsenal of functional monomers directing self-assembly through packing frustration or response to various fields. The mobility in solution further allows the manipulation of self-assembly processes into specific directions by clever choice of environmental conditions. This review focuses on practical concepts that direct self-assembly into predictable nanostructures, while narrowing particle dispersity with respect to size, shape and internal morphology. The growing understanding of underlying self-assembly mechanisms expands the number of experimental concepts providing the means to target and manipulate progressively complex superstructures.

Architecturing hierarchical function layers on self-assembled viral templates as 3D nano-array electrodes for integrated Li-ion microbatteries.

PubMed

Liu, Yihang; Zhang, Wei; Zhu, Yujie; Luo, Yanting; Xu, Yunhua; Brown, Adam; Culver, James N; Lundgren, Cynthia A; Xu, Kang; Wang, Yuan; Wang, Chunsheng

2013-01-09

This work enables an elegant bottom-up solution to engineer 3D microbattery arrays as integral power sources for microelectronics. Thus, multilayers of functional materials were hierarchically architectured over tobacco mosaic virus (TMV) templates that were genetically modified to self-assemble in a vertical manner on current-collectors, so that optimum power and energy densities accompanied with excellent cycle-life could be achieved on a minimum footprint. The resultant microbattery based on self-aligned LiFePO(4) nanoforests of shell-core-shell structure, with precise arrangement of various auxiliary material layers including a central nanometric metal core as direct electronic pathway to current collector, delivers excellent energy density and stable cycling stability only rivaled by the best Li-ion batteries of conventional configurations, while providing rate performance per foot-print and on-site manufacturability unavailable from the latter. This approach could open a new avenue for microelectromechanical systems (MEMS) applications, which would significantly benefit from the concept that electrochemically active components be directly engineered and fabricated as an integral part of the integrated circuit (IC).

DNA-mediated engineering of multicomponent enzyme crystals

PubMed Central

Brodin, Jeffrey D.; Auyeung, Evelyn; Mirkin, Chad A.

2015-01-01

The ability to predictably control the coassembly of multiple nanoscale building blocks, especially those with disparate chemical and physical properties such as biomolecules and inorganic nanoparticles, has far-reaching implications in catalysis, sensing, and photonics, but a generalizable strategy for engineering specific contacts between these particles is an outstanding challenge. This is especially true in the case of proteins, where the types of possible interparticle interactions are numerous, diverse, and complex. Herein, we explore the concept of trading protein–protein interactions for DNA–DNA interactions to direct the assembly of two nucleic-acid–functionalized proteins with distinct surface chemistries into six unique lattices composed of catalytically active proteins, or of a combination of proteins and DNA-modified gold nanoparticles. The programmable nature of DNA–DNA interactions used in this strategy allows us to control the lattice symmetries and unit cell constants, as well as the compositions and habit, of the resulting crystals. This study provides a potentially generalizable strategy for constructing a unique class of materials that take advantage of the diverse morphologies, surface chemistries, and functionalities of proteins for assembling functional crystalline materials. PMID:25831510

Novel Ultrahigh Vacuum System for Chip-Scale Trapped Ion Quantum Computing

NASA Astrophysics Data System (ADS)

Chen, Shaw-Pin; Trapped Team

2011-05-01

This presentation reports the experimental results of an ultrahigh vacuum (UHV) system as a scheme to implement scalable trapped-ion quantum computers that use micro-fabricated ion traps as fundamental building blocks. The novelty of this system resides in our design, material selection, mechanical liability, low complexity of assembly, and reduced signal interference between DC and RF electrodes. Our system utilizes RF isolation and onsite-filtering topologies to attenuate AC signals generated from the resonator. We use a UHV compatible printed circuit board (PCB) material to perform DC routing, while the RF high and RF ground received separated routing via wire-wrapping. The standard PCB fabrication process enabled us to implement ceramic-based filter components adjacent to the chip trap. The DC electrodes are connected to air-side electrical feed through using four 25D adaptors made with polyether ether ketone (PEEK). The assembly process of this system is straight forward and in-chamber structure is self-supporting. We report on initial testing of this concept with a linear chip trap fabricated by the Sandia National Labs.

DNA-mediated engineering of multicomponent enzyme crystals

DOE PAGES

Brodin, Jeffrey D.; Auyeung, Evelyn; Mirkin, Chad A.

2015-03-23

The ability to predictably control the coassembly of multiple nanoscale building blocks, especially those with disparate chemical and physical properties such as biomolecules and inorganic nanoparticles, has far-reaching implications in catalysis, sensing, and photonics, but a generalizable strategy for engineering specific contacts between these particles is an outstanding challenge. This is especially true in the case of proteins, where the types of possible interparticle interactions are numerous, diverse, and complex. In this paper, we explore the concept of trading protein–protein interactions for DNA–DNA interactions to direct the assembly of two nucleic-acid–functionalized proteins with distinct surface chemistries into six unique latticesmore » composed of catalytically active proteins, or of a combination of proteins and DNA-modified gold nanoparticles. The programmable nature of DNA–DNA interactions used in this strategy allows us to control the lattice symmetries and unit cell constants, as well as the compositions and habit, of the resulting crystals. Finally, this study provides a potentially generalizable strategy for constructing a unique class of materials that take advantage of the diverse morphologies, surface chemistries, and functionalities of proteins for assembling functional crystalline materials.« less

Mechanical design for the Evryscope: a minute cadence, 10,000-square-degree FoV, gigapixel-scale telescope

NASA Astrophysics Data System (ADS)

Ratzloff, Jeff; Law, Nicholas M.; Fors, Octavi; Wulfken, Philip J.

2015-01-01

We designed, tested, prototyped and built a compact 27-camera robotic telescope that images 10,000 square degrees in 2-minute exposures. We exploit mass produced interline CCD Cameras with Rokinon consumer lenses to economically build a telescope that covers this large part of the sky simultaneously with a good enough pixel sampling to avoid the confusion limit over most of the sky. We developed the initial concept into a 3-d mechanical design with the aid of computer modeling programs. Significant design components include the camera assembly-mounting modules, the hemispherical support structure, and the instrument base structure. We simulated flexure and material stress in each of the three main components, which helped us optimize the rigidity and materials selection, while reducing weight. The camera mounts are CNC aluminum and the support shell is reinforced fiberglass. Other significant project components include optimizing camera locations, camera alignment, thermal analysis, environmental sealing, wind protection, and ease of access to internal components. The Evryscope will be assembled at UNC Chapel Hill and deployed to the CTIO in 2015.

Self-Assembled NiO/Ni(OH)2 Nanoflakes as Active Material for High-Power and High-Energy Hybrid Rechargeable Battery.

PubMed

Lee, Dong Un; Fu, Jing; Park, Moon Gyu; Liu, Hao; Ghorbani Kashkooli, Ali; Chen, Zhongwei

2016-03-09

Herein, a proof-of-concept of novel hybrid rechargeable battery based on electrochemical reactions of both nickel-zinc and zinc-air batteries is demonstrated using NiO/Ni(OH)2 nanoflakes self-assembled into mesoporous spheres as the active electrode material. The hybrid battery operates on two sets of fundamentally different battery reactions combined at the cell level, unlike in other hybrid systems where batteries of different reactions are simply connected through an external circuitry. As a result of combining nickel-zinc and zinc-air reactions, the hybrid battery demonstrates both remarkably high power density (volumetric, 14 000 W L(-1); gravimetric, 2700 W kg(-1)) and energy density of 980 W h kg(-1), significantly outperforming the performances of a conventional zinc-air battery. Furthermore, the hybrid battery demonstrates excellent charge rate capability up to 10 times faster than the rate of discharge without any capacity and voltage degradations, which makes it highly suited for large-scale applications such as electric vehicle propulsion and smart-grid energy storage.

International Human Mission to Mars: Analyzing A Conceptual Launch and Assembly Campaign

NASA Technical Reports Server (NTRS)

Cates, Grant; Stromgren, Chel; Arney, Dale; Cirillo, William; Goodliff, Kandyce

2014-01-01

In July of 2013, U.S. Congressman Kennedy (D-Mass.) successfully offered an amendment to H.R. 2687, the National Aeronautics and Space Administration Authorization Act of 2013. "International Participation—The President should invite the United States partners in the International Space Station program and other nations, as appropriate, to participate in an international initiative under the leadership of the United States to achieve the goal of successfully conducting a crewed mission to the surface of Mars." This paper presents a concept for an international campaign to launch and assemble a crewed Mars Transfer Vehicle. NASA’s “Human Exploration of Mars: Design Reference Architecture 5.0” (DRA 5.0) was used as the point of departure for this concept. DRA 5.0 assumed that the launch and assembly campaign would be conducted using NASA launch vehicles. The concept presented utilizes a mixed fleet of NASA Space Launch System (SLS), U.S. commercial and international launch vehicles to accomplish the launch and assembly campaign. This concept has the benefit of potentially reducing the campaign duration. However, the additional complexity of the campaign must also be considered. The reliability of the launch and assembly campaign utilizing SLS launches augmented with commercial and international launch vehicles is analyzed and compared using discrete event simulation.

A new piezoelectric energy harvesting design concept: multimodal energy harvesting skin.

PubMed

Lee, Soobum; Youn, Byeng D

2011-03-01

This paper presents an advanced design concept for a piezoelectric energy harvesting (EH), referred to as multimodal EH skin. This EH design facilitates the use of multimodal vibration and enhances power harvesting efficiency. The multimodal EH skin is an extension of our previous work, EH skin, which was an innovative design paradigm for a piezoelectric energy harvester: a vibrating skin structure and an additional thin piezoelectric layer in one device. A computational (finite element) model of the multilayered assembly - the vibrating skin structure and piezoelectric layer - is constructed and the optimal topology and/or shape of the piezoelectric layer is found for maximum power generation from multiple vibration modes. A design rationale for the multimodal EH skin was proposed: designing a piezoelectric material distribution and external resistors. In the material design step, the piezoelectric material is segmented by inflection lines from multiple vibration modes of interests to minimize voltage cancellation. The inflection lines are detected using the voltage phase. In the external resistor design step, the resistor values are found for each segment to maximize power output. The presented design concept, which can be applied to any engineering system with multimodal harmonic-vibrating skins, was applied to two case studies: an aircraft skin and a power transformer panel. The excellent performance of multimodal EH skin was demonstrated, showing larger power generation than EH skin without segmentation or unimodal EH skin.

A self-assembled three-dimensional cloak in the visible

PubMed Central

Mühlig, Stefan; Cunningham, Alastair; Dintinger, José; Farhat, Mohamed; Hasan, Shakeeb Bin; Scharf, Toralf; Bürgi, Thomas; Lederer, Falk; Rockstuhl, Carsten

2013-01-01

An invisibility cloak has been designed, realized and characterized. The cloak hides free-standing sub-wavelength three-dimensional objects at the short wavelength edge of the visible spectrum. By a bottom-up approach the cloak was self-assembled around the object. Such fabrication approach constitutes a further important step towards real world applications of cloaking; leaving the realm of curiosity. The cloak and the way it was fabricated opens an avenue for many spectacular nanooptical applications such as non-disturbing sensors and photo-detectors, highly efficient solar cells, or optical nanoantenna arrays with strongly suppressed cross-talk to mention only a few. Our results rely on the successful combination of concepts from various disciplines, i.e. chemistry, material science, and plasmonics. Consequently, this work will stimulate these fields by unraveling new paths for future research. PMID:23921452

Initial utilization of the CVIRB video production facility

NASA Technical Reports Server (NTRS)

Parrish, Russell V.; Busquets, Anthony M.; Hogge, Thomas W.

1987-01-01

Video disk technology is one of the central themes of a technology demonstrator workstation being assembled as a man/machine interface for the Space Station Data Management Test Bed at Johnson Space Center. Langley Research Center personnel involved in the conception and implementation of this workstation have assembled a video production facility to allow production of video disk material for this propose. This paper documents the initial familiarization efforts in the field of video production for those personnel and that facility. Although the entire video disk production cycle was not operational for this initial effort, the production of a simulated disk on video tape did acquaint the personnel with the processes involved and with the operation of the hardware. Invaluable experience in storyboarding, script writing, audio and video recording, and audio and video editing was gained in the production process.

Magnetic Propulsion of Microswimmers with DNA-Based Flagellar Bundles.

PubMed

Maier, Alexander M; Weig, Cornelius; Oswald, Peter; Frey, Erwin; Fischer, Peer; Liedl, Tim

2016-02-10

We show that DNA-based self-assembly can serve as a general and flexible tool to construct artificial flagella of several micrometers in length and only tens of nanometers in diameter. By attaching the DNA flagella to biocompatible magnetic microparticles, we provide a proof of concept demonstration of hybrid structures that, when rotated in an external magnetic field, propel by means of a flagellar bundle, similar to self-propelling peritrichous bacteria. Our theoretical analysis predicts that flagellar bundles that possess a length-dependent bending stiffness should exhibit a superior swimming speed compared to swimmers with a single appendage. The DNA self-assembly method permits the realization of these improved flagellar bundles in good agreement with our quantitative model. DNA flagella with well-controlled shape could fundamentally increase the functionality of fully biocompatible nanorobots and extend the scope and complexity of active materials.

Theoretical and experimental investigation of architected core materials incorporating negative stiffness elements

NASA Astrophysics Data System (ADS)

Chang, Chia-Ming; Keefe, Andrew; Carter, William B.; Henry, Christopher P.; McKnight, Geoff P.

2014-04-01

Structural assemblies incorporating negative stiffness elements have been shown to provide both tunable damping properties and simultaneous high stiffness and damping over prescribed displacement regions. In this paper we explore the design space for negative stiffness based assemblies using analytical modeling combined with finite element analysis. A simplified spring model demonstrates the effects of element stiffness, geometry, and preloads on the damping and stiffness performance. Simplified analytical models were validated for realistic structural implementations through finite element analysis. A series of complementary experiments was conducted to compare with modeling and determine the effects of each element on the system response. The measured damping performance follows the theoretical predictions obtained by analytical modeling. We applied these concepts to a novel sandwich core structure that exhibited combined stiffness and damping properties 8 times greater than existing foam core technologies.

A Modular Orbital Demonstration of an Evolvable Space Telescope (MODEST)

NASA Astrophysics Data System (ADS)

Conti, Alberto; Arenberg, Jonathan; Baldauf, Brian

2017-01-01

The “Search for Life” (direct imaging of earth-like planets) will require extremely stable telescopes with apertures in the 10 m to 20 m range. Such apertures are larger than what can be delivered to space using current or planned future launch vehicles. Building and assembling large telescopes in space is therefore likely to require not only multiple launches but importantly assembly in spce. As a result, space-based telescopes with large apertures will require major changes to our conventional telescope design and architecture.Here we report on the concept for the Modular Orbital Demonstration of an Evolvable Space Telescope (MODEST) to demonstrates the on-orbit robotic and/or astronaut assembly of an optical telescope in space. MODEST is a proposed International Space Station (ISS demonstration that will make use of the standard Express Logistics Carriers (ELCs) and can mounted to one of a variety of ISS pallets.MODEST will provides significant risk reduction for the next generation of space observatories, and demonstrates the technology needed to assemble a six-mirror phased telescope. Key modest features include the use of an active primary optical surface with wavefront feedback control to allow on-orbit optimization, and the precise surface control to meet optical system wavefront and stability requirements.MODEST will also be used to evaluate advances in lightweight mirror and metering structure materials such as SiC or Carbon Fiber Reinforced Polymer (CFRP) that have excellent mechanical and thermal properties, e.g. high stiffness, high modulus, high thermal conductivity, and low thermal expansion. Mirrors built from these materials can be rapidly replicated in a highly cost effective manner, making them an excellent candidate for a low cost, high performance Optical Telescope Assembly paving the way for enabling affordable solutions for the next generation of large aperture space-based telescope.MODEST post-assembly value includes space, ground, and environmental studies, a testbed for new instruments, and a tool for student’s exploration of space.

Development of termination and utilization concepts for flat conductor cables. Volume 3: Cost study comparison, flat versus round conductor cable

NASA Technical Reports Server (NTRS)

1972-01-01

A cost study comparing flat conductor cable (FCC) with small-gage wire (SGW) and conventional round conductor cable (RCC) is presented. This study was based on a vehicle wiring system consisting of 110,000 ft of conventional RCC equally divided between AWG sizes 20,22, and 24 using MIL-W-81044-type wire and MIL-C-26500 circular connectors. Basic cost data were developed on a similar-sized commercial jet airplane wiring system on a previous company R&D program in which advanced wiring techniques were carried through equivalent installations on an airplane mockup; and on data developed on typical average bundles during this program. Various cost elements included were engineering labor, operations (manufacturing) labor, material costs, and cost impact on payload. Engineering labor includes design, wiring system integration, wiring diagrams and cable assembly drawings, wire installations, and other related supporting functions such as the electronic data processing for the wiring. Operations labor includes mockup, tooling and production planning, fabrication, assembly, installation, and quality control cost impact on payload is the conversion of wiring system weight variations through use of different wiring concepts to program payload benefits in terms of dollars.

Architectonics: Design of Molecular Architecture for Functional Applications.

PubMed

Avinash, M B; Govindaraju, Thimmaiah

2018-02-20

The term architectonics has its roots in the architectural and philosophical (as early as 1600s) literature that refers to "the theory of structure" and "the structure of theory", respectively. The concept of architectonics has been adapted to advance the field of molecular self-assembly and termed as molecular architectonics. In essence, the methodology of organizing molecular units in the required and controlled configurations to develop advanced functional systems for materials and biological applications comprises the field of molecular architectonics. This concept of designing noncovalent systems enables to focus on different functional aspects of designer molecules for biological and nonbiological applications and also strengthens our efforts toward the mastery over the art of controlled molecular self-assemblies. Programming complex molecular interactions and assemblies for specific functions has been one of the most challenging tasks in the modern era. Meticulously ordered molecular assemblies can impart remarkable developments in several areas spanning energy, health, and environment. For example, the well-defined nano-, micro-, and macroarchitectures of functional molecules with specific molecular ordering possess potential applications in flexible electronics, photovoltaics, photonic crystals, microreactors, sensors, drug delivery, biomedicine, and superhydrophobic coatings, among others. The functional molecular architectures having unparalleled properties are widely evident in various designs of Nature. By drawing inspirations from Nature, intended molecular architectures can be designed and developed to harvest various functions, as there is an inexhaustible resource and scope. In this Account, we present exquisite designer molecules developed by our group and others with an objective to master the art of molecular recognition and self-assembly for functional applications. We demonstrate the tailor-ability of molecular self-assemblies by employing biomolecules like amino acids and nucleobases as auxiliaries. Naphthalenediimide (NDI), perylenediimide (PDI), and few other molecular systems serve as functional modules. The effects of stereochemistry and minute structural modifications in the molecular designs on the supramolecular interactions, and construction of self-assembled zero-dimensional (OD), one-dimensional (1D), and two-dimensional (2D) nano- and microarchitectures like particles, spheres, cups, bowls, fibers, belts, helical belts, supercoiled helices, sheets, fractals, and honeycomb-like arrays are discussed in extensive detail. Additionally, we present molecular systems that showcase the elegant designs of coassembly, templated assembly, hierarchical assembly, transient self-assembly, chiral denaturation, retentive helical memory, self-replication, supramolecular regulation, supramolecular speciation, supernon linearity, dynamic pathway complexity, supramolecular heterojunction, living supramolecular polymerization, and molecular machines. Finally, we describe the molecular engineering principles learnt over the years that have led to several applications, namely, organic electronics, self-cleaning, high-mechanical strength, and tissue engineering.

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

Tucker, Michael C.; Phillips, Adam; Weber, Adam Z.

We proposed and developed an all-iron redox flow battery for end users without access to an electricity grid. The concept is a low-cost battery which the user assembles, discharges, and then disposes of the active materials. Our design goals are: (1) minimize upfront cost, (2) maximize discharge energy, and (3) utilize non-toxic and environmentally benign materials. These are different goals than typically considered for electrochemical battery technology, which provides the opportunity for a novel solution. The selected materials are: low-carbon-steel negative electrode, paper separator, porous-carbon-paper positive electrode, and electrolyte solution containing 0.5 m Fe 2 (SO 4 ) 3 activemore » material and 1.2 m NaCl supporting electrolyte. Furthermore, with these materials, an average power density around 20 mW cm -2 and a maximum energy density of 11.5 Wh L -1 are achieved. A simple cost model indicates the consumable materials cost US$6.45 per kWh -1 , or only US$0.034 per mobile phone charge.« less

Towards Cluster-Assembled Materials of True Monodispersity in Size and Chemical Environment: Synthesis, Dynamics and Activity

DTIC Science & Technology

2016-10-27

AFRL-AFOSR-UK-TR-2016-0037 Towards cluster-assembled materials of true monodispersity in size and chemical environment: Synthesis, Dynamics and...Towards cluster-assembled materials of true monodispersity in size and chemical environment: synthesis, dynamics and activity 5a.  CONTRACT NUMBER 5b...report Towards cluster-assembled materials of true monodispersity in size and chemical environment: Synthesis, Dynamics and Activity Ulrich Heiz

n/a

NASA Image and Video Library

1985-11-01

The crew assigned to the STS-61B mission included (kneeling left to right) Bryan D. O’conner, pilot; and Brewster H. Shaw, commander. On the back row, left to right, are Charles D. Walker, payload specialist; mission specialists Jerry L. Ross, Mary L. Cleave, and Sherwood C. Spring; and Rodolpho Neri Vela, payload specialist. Launched aboard the Space Shuttle Atlantis November 28, 1985 at 7:29:00 pm (EST), the STS-61B mission’s primary payload included three communications satellites: MORELOS-B (Mexico); AUSSAT-2 (Autralia); and SATCOM KU-2 (RCA Americom. Two experiments were conducted to test assembling erectable structures in space: EASE (Experimental Assembly of Structures in Extravehicular Activity), and ACCESS (Assembly Concept for Construction of Erectable Space Structure). In a joint venture between NASA/Langley Research Center in Hampton, VA and Marshall Space Flight Center (MSFC), the Assembly Concept for Construction of Erectable Space Structures (ACCESS) was developed and demonstrated at MSFC's Neutral Buoyancy Simulator (NBS). The primary objective of this experiment was to test the ACCESS structural assembly concept for suitability as the framework for larger space structures and to identify ways to improve the productivity of space construction.

STS-61B Crew Portrait

NASA Technical Reports Server (NTRS)

1985-01-01

The crew assigned to the STS-61B mission included (kneeling left to right) Bryan D. O'conner, pilot; and Brewster H. Shaw, commander. On the back row, left to right, are Charles D. Walker, payload specialist; mission specialists Jerry L. Ross, Mary L. Cleave, and Sherwood C. Spring; and Rodolpho Neri Vela, payload specialist. Launched aboard the Space Shuttle Atlantis November 28, 1985 at 7:29:00 pm (EST), the STS-61B mission's primary payload included three communications satellites: MORELOS-B (Mexico); AUSSAT-2 (Autralia); and SATCOM KU-2 (RCA Americom. Two experiments were conducted to test assembling erectable structures in space: EASE (Experimental Assembly of Structures in Extravehicular Activity), and ACCESS (Assembly Concept for Construction of Erectable Space Structure). In a joint venture between NASA/Langley Research Center in Hampton, VA and Marshall Space Flight Center (MSFC), the Assembly Concept for Construction of Erectable Space Structures (ACCESS) was developed and demonstrated at MSFC's Neutral Buoyancy Simulator (NBS). The primary objective of this experiment was to test the ACCESS structural assembly concept for suitability as the framework for larger space structures and to identify ways to improve the productivity of space construction.

DNA-nanoparticle assemblies go organic: macroscopic polymeric materials with nanosized features.

PubMed

Mentovich, Elad D; Livanov, Konstantin; Prusty, Deepak K; Sowwan, Mukules; Richter, Shachar

2012-05-30

One of the goals in the field of structural DNA nanotechnology is the use of DNA to build up 2- and 3-D nanostructures. The research in this field is motivated by the remarkable structural features of DNA as well as by its unique and reversible recognition properties. Nucleic acids can be used alone as the skeleton of a broad range of periodic nanopatterns and nanoobjects and in addition, DNA can serve as a linker or template to form DNA-hybrid structures with other materials. This approach can be used for the development of new detection strategies as well as nanoelectronic structures and devices. Here we present a new method for the generation of unprecedented all-organic conjugated-polymer nanoparticle networks guided by DNA, based on a hierarchical self-assembly process. First, microphase separation of amphiphilic block copolymers induced the formation of spherical nanoobjects. As a second ordering concept, DNA base pairing has been employed for the controlled spatial definition of the conjugated-polymer particles within the bulk material. These networks offer the flexibility and the diversity of soft polymeric materials. Thus, simple chemical methodologies could be applied in order to tune the network's electrical, optical and mechanical properties. One- two- and three-dimensional networks have been successfully formed. Common to all morphologies is the integrity of the micelles consisting of DNA block copolymer (DBC), which creates an all-organic engineered network.

Optical Sensors for Detection of Amino Acids.

PubMed

Pettiwala, Aafrin M; Singh, Prabhat K

2017-11-06

Amino acids are crucially involved in a myriad of biological processes. Any aberrant changes in physiological level of amino acids often manifest in common metabolic disorders, serious neurological conditions and cardiovascular diseases. Thus, devising methods for detection of trace amounts of amino acids becomes highly elemental to their efficient clinical diagnosis. Recently, the domain of developing optical sensors for detection of amino acids has witnessed significant activity which is the focus of the current review article. We undertook a detailed search of the peer-reviewed literature that primarily deals with optical sensors for amino acids and focuses on the use of different type of materials as a sensing platform. Ninety-five papers have been included in the review, majority of which deals with optical sensors. We attempt to systematically classify these contributions based on applications of various chemical and biological scaffolds such as polymers, supramolecular assemblies, nanoparticles, DNA, heparin etc. for the sensing of amino acids. This review identifies that supramolecular assemblies and nanomaterial continue to be commonly used materials to devise sensors for amino acids followed by surfactant assemblies. The broad implications of amino acids in human health and diagnosis have stirred a lot of interest to develop optimized optical detection systems for amino acids in recent years, using different materials based on chemical and biological scaffolds. We have also attempted to highlight the merits and demerits of some of the noteworthy sensor systems to instigate further efforts for constructing amino acids sensor based on unconventional concepts. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Development of assembly and joint concepts for erectable space structures

NASA Technical Reports Server (NTRS)

Jacquemin, G. G.; Bluck, R. M.; Grotbeck, G. H.; Johnson, R. R.

1980-01-01

The technology associated with the on-orbit assembly of tetrahedral truss platforms erected of graphite epoxy tapered columns is examined. Associated with the assembly process is the design and fabrication of nine member node joints. Two such joints demonstrating somewhat different technology were designed and fabricated. Two methods of automatic assembly using the node designs were investigated, and the time of assembly of tetrahedral truss structures up to 1 square km in size was estimated. The effect of column and node joint packaging on the Space Shuttle cargo bay is examined. A brief discussion is included of operating cost considerations and the selection of energy sources. Consideration was given to the design assembly machines from 5 m to 20 m. The smaller machines, mounted on the Space Shuttle, are deployable and restowable. They provide a means of demonstrating the capabilities of the concept and of erecting small specialized platforms on relatively short notice.

Application of the Modular Automated Reconfigurable Assembly System (MARAS) concept to adaptable vision gauging and parts feeding

NASA Technical Reports Server (NTRS)

By, Andre Bernard; Caron, Ken; Rothenberg, Michael; Sales, Vic

1994-01-01

This paper presents the first phase results of a collaborative effort between university researchers and a flexible assembly systems integrator to implement a comprehensive modular approach to flexible assembly automation. This approach, named MARAS (Modular Automated Reconfigurable Assembly System), has been structured to support multiple levels of modularity in terms of both physical components and system control functions. The initial focus of the MARAS development has been on parts gauging and feeding operations for cylinder lock assembly. This phase is nearing completion and has resulted in the development of a highly configurable system for vision gauging functions on a wide range of small components (2 mm to 100 mm in size). The reconfigurable concepts implemented in this adaptive Vision Gauging Module (VGM) are now being extended to applicable aspects of the singulating, selecting, and orienting functions required for the flexible feeding of similar mechanical components and assemblies.

Origami Inspired Self-assembly of Patterned and Reconfigurable Particles

PubMed Central

Pandey, Shivendra; Gultepe, Evin; Gracias, David H.

2013-01-01

There are numerous techniques such as photolithography, electron-beam lithography and soft-lithography that can be used to precisely pattern two dimensional (2D) structures. These technologies are mature, offer high precision and many of them can be implemented in a high-throughput manner. We leverage the advantages of planar lithography and combine them with self-folding methods1-20 wherein physical forces derived from surface tension or residual stress, are used to curve or fold planar structures into three dimensional (3D) structures. In doing so, we make it possible to mass produce precisely patterned static and reconfigurable particles that are challenging to synthesize. In this paper, we detail visualized experimental protocols to create patterned particles, notably, (a) permanently bonded, hollow, polyhedra that self-assemble and self-seal due to the minimization of surface energy of liquefied hinges21-23 and (b) grippers that self-fold due to residual stress powered hinges24,25. The specific protocol described can be used to create particles with overall sizes ranging from the micrometer to the centimeter length scales. Further, arbitrary patterns can be defined on the surfaces of the particles of importance in colloidal science, electronics, optics and medicine. More generally, the concept of self-assembling mechanically rigid particles with self-sealing hinges is applicable, with some process modifications, to the creation of particles at even smaller, 100 nm length scales22, 26 and with a range of materials including metals21, semiconductors9 and polymers27. With respect to residual stress powered actuation of reconfigurable grasping devices, our specific protocol utilizes chromium hinges of relevance to devices with sizes ranging from 100 μm to 2.5 mm. However, more generally, the concept of such tether-free residual stress powered actuation can be used with alternate high-stress materials such as heteroepitaxially deposited semiconductor films5,7 to possibly create even smaller nanoscale grasping devices. PMID:23407436

A structurally adaptive space crane concept for assembling space systems on orbit

NASA Technical Reports Server (NTRS)

Dorsey, John T.; Sutter, Thomas R.; Wu, K. C.

1992-01-01

A space crane concept is presented which is based on erectable truss hardware to achieve high stiffness and low mass booms and articulating-truss joints which can be assembled on orbit. The hardware is characterized by linear load-deflection response and is structurally predictable. The crane can be reconfigured into different geometries to meet future assembly requirements. Articulating-truss joint concepts with significantly different geometries are analyzed and found to have similar static and dynamic performance, which indicates that criteria other than structural and kinematic performance can be used to select a joint. Passive damping and an open-loop preshaped command input technique greatly enhance the structural damping in the space crane and may preclude the need for an active vibrations suppression system.

Automated solar panel assembly line

NASA Technical Reports Server (NTRS)

Somberg, H.

1981-01-01

The initial stage of the automated solar panel assembly line program was devoted to concept development and proof of approach through simple experimental verification. In this phase, laboratory bench models were built to demonstrate and verify concepts. Following this phase was machine design and integration of the various machine elements. The third phase was machine assembly and debugging. In this phase, the various elements were operated as a unit and modifications were made as required. The final stage of development was the demonstration of the equipment in a pilot production operation.

GaAs photovoltaics and optoelectronics using releasable multilayer epitaxial assemblies.

PubMed

Yoon, Jongseung; Jo, Sungjin; Chun, Ik Su; Jung, Inhwa; Kim, Hoon-Sik; Meitl, Matthew; Menard, Etienne; Li, Xiuling; Coleman, James J; Paik, Ungyu; Rogers, John A

2010-05-20

Compound semiconductors like gallium arsenide (GaAs) provide advantages over silicon for many applications, owing to their direct bandgaps and high electron mobilities. Examples range from efficient photovoltaic devices to radio-frequency electronics and most forms of optoelectronics. However, growing large, high quality wafers of these materials, and intimately integrating them on silicon or amorphous substrates (such as glass or plastic) is expensive, which restricts their use. Here we describe materials and fabrication concepts that address many of these challenges, through the use of films of GaAs or AlGaAs grown in thick, multilayer epitaxial assemblies, then separated from each other and distributed on foreign substrates by printing. This method yields large quantities of high quality semiconductor material capable of device integration in large area formats, in a manner that also allows the wafer to be reused for additional growths. We demonstrate some capabilities of this approach with three different applications: GaAs-based metal semiconductor field effect transistors and logic gates on plates of glass, near-infrared imaging devices on wafers of silicon, and photovoltaic modules on sheets of plastic. These results illustrate the implementation of compound semiconductors such as GaAs in applications whose cost structures, formats, area coverages or modes of use are incompatible with conventional growth or integration strategies.

Derivation of Multiple Covarying Material and Process Parameters Using Physics-Based Modeling of X-ray Data

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

Khaira, Gurdaman; Doxastakis, Manolis; Bowen, Alec

There is considerable interest in developing multimodal characterization frameworks capable of probing critical properties of complex materials by relying on distinct, complementary methods or tools. Any such framework should maximize the amount of information that is extracted from any given experiment and should be sufficiently powerful and efficient to enable on-the-fly analysis of multiple measurements in a self-consistent manner. Such a framework is demonstrated in this work in the context of self-assembling polymeric materials, where theory and simulations provide the language to seamlessly mesh experimental data from two different scattering measurements. Specifically, the samples considered here consist of diblock copolymersmore » (BCP) that are self-assembled on chemically nanopatterned surfaces. The copolymers microphase separate into ordered lamellae with characteristic dimensions on the scale of tens of nanometers that are perfectly aligned by the substrate over macroscopic areas. These aligned lamellar samples provide ideal standards with which to develop the formalism introduced in this work and, more generally, the concept of high-information-content, multimodal experimentation. The outcomes of the proposed analysis are then compared to images generated by 3D scanning electron microscopy tomography, serving to validate the merit of the framework and ideas proposed here.« less

Self-assembled lipid bilayer materials

DOEpatents

Sasaki, Darryl Y.; Waggoner, Tina A.; Last, Julie A.

2005-11-08

The present invention is a self-assembling material comprised of stacks of lipid bilayers formed in a columnar structure, where the assembly process is mediated and regulated by chemical recognition events. The material, through the chemical recognition interactions, has a self-regulating system that corrects the radial size of the assembly creating a uniform diameter throughout most of the structure. The materials form and are stable in aqueous solution. These materials are useful as structural elements for the architecture of materials and components in nanotechnology, efficient light harvesting systems for optical sensing, chemical processing centers, and drug delivery vehicles.

Two-Dimensional Fluidization of Nanomaterials via Biomimetic Membranes towards Assisted Self Assembly

NASA Astrophysics Data System (ADS)

Kelly, Kathleen

Materials that take advantage of the exceptional properties of nano-meter sized aggregates of atoms are poised to play an important role in future technologies. Prime examples for such nano-materials that have an extremely large surface to volume ratio and thus are physically determined by surface related effects are quantum dots (qdots) and carbon nanotubes (CNTs). The production of such manmade nano-objects has by now become routine and even commercialized. However, the controlled assembly of individual nano-sized building blocks into larger structures of higher geometric and functional complexity has proven to be much more challenging. Yet, this is exactly what is required for many applications that have transformative potential for new technologies. If the tedious procedure to sequentially position individual nano-objects is to be forgone, the assembly of such objects into larger structures needs to be implicitly encoded and many ways to bestow such self-assembly abilities onto nano objects are being developed. Yet, as overall size and complexity of such self-assembled structures increases, kinetic and geometric frustration begin to prevent the system to achieve the desired configuration. In nature, this problem is solved by relying on guided or forced variants of the self-assembly approach. To translate such concepts into the realm of man-made nano-technology, ways to dynamically manipulate nano-materials need to be devised. Thus, in the first part of this work, I provide a proof of concept that supported lipid bilayers (SLBs) that exhibit free lateral diffusion of their constituents can be utilized as a two-dimensional platform for active nano-material manipulation. We used streptavidin coated quantum dots (Q-dots) as a model nano-building-block. Q-dots are 0-dimensional nanomaterials engineered to be fluorescent based solely on their diameter making visualization convenient. Biotinylated lipids were used to tether Q-dots to a SLB and we observed that the 2-dimensional fluidity of the bilayer was translated to the quantum dots as they freely diffused. The quantum dots were visualized using wide-field fluorescent microscopy and single particle tracking techniques were employed to analyze their dynamic behavior. Next, an electric field was applied to the system to induce electroosmotic flow (EOF) which creates a bulk flow of the buffer solution. The quantum dots were again tracked and ballistic motion was observed in the particle tracks due to the electroosmosis in the system. This proved that SLBs could be used as a two-dimensional fluid platform for nanomaterials and electroosmosis can be used to manipulate the motion of the Q-dots once they are tethered to the membrane. Next, we set out to employ the same technique to carbon nanotubes (CNTs), which are known for their highly versatile mechanical and electrical properties. However, carbon nanotubes are extremely hydrophobic and tend to aggregate in aqueous solutions which negatively impacts the viability of tethering the CNTs to the bilayer, fluorescently staining and then imaging them. First, we had to solubilize the CNTs such that they were monodisperse and characterize the CNT-detergent solutions. We were able to create monodisperse solutions of CNTs such that the detergent levels were low enough that the integrity of the bilayer was intact. We were also able to fluorescently label the CNTs in order to visualize them, and tether them to a SLB using a peptide sequence. Future directions of this project would include employing EOF to mobilize the CNTs and use a more sophisticated single particle tracking software to track individual CNTs and analyze their motion.

Solvent mediated hybrid 2D materials: black phosphorus - graphene heterostructured building blocks assembled for sodium ion batteries.

PubMed

Li, Mengya; Muralidharan, Nitin; Moyer, Kathleen; Pint, Cary L

2018-06-07

Here we demonstrate the broad capability to exploit interactions at different length scales in 2D materials to prepare macroscopic functional materials containing hybrid black phosphorus/graphene (BP/G) heterostructured building blocks. First, heterostructured 2D building blocks are self-assembled during co-exfoliation in the solution phase based on electrostatic attraction of different 2D materials. Second, electrophoretic deposition is used as a tool to assemble these building blocks into macroscopic films containing these self-assembled 2D heterostructures. Characterization of deposits formed using this technique elucidates the presence of stacked and sandwiched 2D heterostructures, and zeta potential measurements confirm the mechanistic interactions driving this assembly. Building on the exceptional sodium alloying capacity of BP, these materials were demonstrated as superior binder-free and additive-free anodes for sodium batteries with specific discharge capacity of 2365 mA h gP-1 and long stable cycling duration. This study demonstrates how controllable co-processing of 2D materials can enable material control for stacking and building block assembly relevant to broad future applications of 2D materials.

Modular Orbital Demonstration of an Evolvable Space Telescope (MODEST)

NASA Astrophysics Data System (ADS)

Baldauf, Brian; Conti, Alberto

2016-01-01

The "Search for Life" via imaging of exoplanets is a mission that requires extremely stable telescopes with apertures in the 10 m to 20 m range. The High Definition Space Telescope (HDST) envisioned for this mission would have an aperture >10 m, which is a larger payload than what can be delivered to space using a single launch vehicle. Building and assembling the mirror segments enabling large telescopes will likely require multiple launches and assembly in space. Space-based telescopes with large apertures will require major changes to system architectures.The Optical Telescope Assembly (OTA) for HDST is a primary mission cost driver. Enabling and affordable solutions for this next generation of large aperture space-based telescope are needed.This paper reports on the concept for the Modular Orbital Demonstration of an Evolvable Space Telescope (MODEST), which demonstrates on-orbit robotic and/or astronaut assembly of a precision optical telescope in space. It will also facilitate demonstration of active correction of phase and mirror shape. MODEST is proposed to be delivered to the ISS using standard Express Logistics Carriers (ELCs) and can mounted to one of a variety of ISS pallets. Post-assembly value includes space, ground, and environmental studies, and a testbed for new instruments. This demonstration program for next generation mirror technology provides significant risk reduction and demonstrates the technology in a six-mirror phased telescope. Other key features of the demonstration include the use of an active primary optical surface with wavefront feedback control that allows on-orbit optimization and demonstration of precise surface control to meet optical system wavefront and stability requirements.MODEST will also be used to evaluate advances in lightweight mirror and metering structure materials such as SiC or Carbon Fiber Reinforced Polymer that have excellent mechanical and thermal properties, e.g. high stiffness, high modulus, high thermal conductivity, and low thermal expansion. It has been demonstrated that mirrors built from these materials can be rapidly replicated in a highly cost effective manner, making these materials excellent candidates for a low cost, high performance OTA.

Modular Orbital Demonstration of an Evolvable Space Telescope

NASA Astrophysics Data System (ADS)

Baldauf, Brian

2016-06-01

The key driver for a telescope's sensitivityis directly related to the size of t he mirror area that collects light from the objects being observed.The "Search for Life" via imaging of exoplanets is a mission that requires extremely stable telescopes with apertures in the 10 m to 20 m range. The HDST envisioned for this mission would have an aperture >10 m, which is a larger payload than can be delivered to space using a single launch vehicle. Building and assembling the mirror segments enabling large telescopes will likely require multiple launches and assembly in space. The Optical Telescope Assembly for HDST is a primary mission cost driver. Enabling affordable solutions for this next generation of large aperture space-based telescope are needed.This reports on the concept for the MODEST, which demonstrates on-orbit robotic and/or astronaut assembly of a precision optical telescope in space. It will facilitate demonstration of active correction of phase and mirror shape. MODEST is proposed to be delivered to the ISS using standard Express Logistics Carriers and can mounted to one of a variety of ISS pallets. Post-assembly value includes space, ground, and environmental studies, a testbed for new instruments, and a tool for student's exploration of space. This demonstration program for next generation mirror technology provides significant risk reduction and demonstrates the technology in a six-mirror phased telescope. Key features of the demonstration include the use of an active primary optical surface with wavefront feedback control that allows on-orbit optimization and demonstration of precise surface control to meet optical system wavefront and stability requirements.MODEST will also be used to evaluate advances in lightweight mirror and metering structure materials such as SiC or Ceramic Matrix Composite that have excellent mechanical and thermal properties, e.g. high stiffness, high thermal conductivity, and low thermal expansion. It has been demonstrated that mirrors built from these materials can be rapidly replicated in a highly cost effective manner, making these materials excellent candidates for a low cost, high performance OTA.

In-space assembly and servicing infrastructures for the Evolvable Space Telescope (EST)

NASA Astrophysics Data System (ADS)

Lillie, Charles F.; MacEwen, Howard A.

2016-07-01

The concept for EST presented in past SPIE forums will benefit significantly from the current efforts of DARPA, NASA and several commercial organizations to develop an in-space infrastructure that will enable on-orbit assembly, servicing, repair and repurposing of space vehicles. Two documents provide particularly relevant discussions: "NASA's Journey to Mars: Pioneering Next Steps in Space Exploration" provides a recent (2015) outline of NASA's thoughts on human deep space exploration and the tools that will enable it, while the "On-Orbit Satellite Servicing Study: Project Report" details a number of the concepts and technologies that must be developed. In this paper we examine the concepts in these and related documents to explore how systems such as EST will shape and support the infrastructure needed by future space vehicles. In so doing, we address previous examples of on-orbit assembly and servicing of space vehicles; the lessons learned from these efforts and the existing systems and facilities available to execute servicing missions; the EST concept for an LUVOIR telescope designed for in-orbit assembly and servicing and the resulting requirements for a servicing vehicle; the use of heavy lift launch vehicles, including the SLS and Exploration Upper Stage to co-manifest other large payloads along with a crewed Orion mission; Deep Space Habitats (DSHs) in cislunar space as a site for assembly and servicing spacecraft vehicles, and a base for Maneuverable Servicing Vehicles; and how space vehicles need to be designed for in-space assembly and servicing (i.e., commonality of parts, systems, modularity, accessibility, and stable maneuverability).

Mirror Material Properties Compiled for Preliminary Design of the Next Generation Space Telescope (30 to 294 Kelvin)

NASA Technical Reports Server (NTRS)

Luz, P. L.; Rice, T.

1998-01-01

This technical memorandum reports on the mirror material properties that were compiled by NASA Marshall Space Flight Center (MSFC) from April 1996 to June 1997 for preliminary design of the Next Generation Space Telescope (NGST) Study. The NGST study began in February 1996, when the Program Development Directorate at NASA MSFC studied the feasibility of the NGST and developed the pre-phase A program for it. After finishing some initial studies and concepts development work on the NGST, MFSC's Program Development Directorate handed this work to the Observatory Projects Office at MSFC and then to NASA Goddard Space Flight Center (GSFC). This technical memorandum was written by MSFC's Preliminary Design Office and Materials and Processes Laboratory for the NGST Optical Telescope Assembly (OTA) team, in Support of NASA GSFC. It contains material properties for 9 mirror Substrate materials, using information from at least 6 industrial Suppliers, 16 textbooks, 44 technical papers, and 130 technical abstracts.

Surface-Directed Assembly of Sequence-Defined Synthetic Polymers into Networks of Hexagonally Patterned Nanoribbons with Controlled Functionalities

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

Chen, Chun-Long; Zuckermann, Ronald N.; DeYoreo, James J.

The exquisite self-assembly of proteins and peptides in nature into highly ordered functional materials has inspired innovative approaches to biomimetic materials design and synthesis. Here we report the assembly of peptoids—a class of highly stable sequence-defined synthetic polymers—into biomimetic materials on mica surfaces. The assembling 12-mer peptoid contains alternating acidic and aromatic residues, and the presence of Ca2+ cations creates peptoid-peptoid and peptoid-mica interactions that drive assembly. In situ atomic force microscopy (AFM) shows that peptoids first assemble into discrete nanoparticles, these particles then transform into hexagonally-patterned nanoribbons on mica surfaces. AFM-based dynamic force spectroscopy (DFS) studies show that peptoid-micamore » interactions are much stronger than peptoidpeptoid interactions in the presence of Ca2+, illuminating the physical parameters that drive peptoid assembly. We further demonstrate the display of functional groups at the N-terminus of assembling peptoid sequence to produce biomimetic materials with similar hierarchical structures. This research demonstrates that surface-directed peptoid assembly can be used as a robust platform to develop biomimetic coating materials for applications.« less

Modular, Reconfigurable, High-Energy Technology Development

NASA Technical Reports Server (NTRS)

Carrington, Connie; Howell, Joe

2006-01-01

The Modular, Reconfigurable High-Energy (MRHE) Technology Demonstrator project was to have been a series of ground-based demonstrations to mature critical technologies needed for in-space assembly of a highpower high-voltage modular spacecraft in low Earth orbit, enabling the development of future modular solar-powered exploration cargo-transport vehicles and infrastructure. MRHE was a project in the High Energy Space Systems (HESS) Program, within NASA's Exploration Systems Research and Technology (ESR&T) Program. NASA participants included Marshall Space Flight Center (MSFC), the Jet Propulsion Laboratory (JPL), and Glenn Research Center (GRC). Contractor participants were the Boeing Phantom Works in Huntsville, AL, Lockheed Martin Advanced Technology Center in Palo Alto, CA, ENTECH, Inc. in Keller, TX, and the University of AL Huntsville (UAH). MRHE's technical objectives were to mature: (a) lightweight, efficient, high-voltage, radiation-resistant solar power generation (SPG) technologies; (b) innovative, lightweight, efficient thermal management systems; (c) efficient, 100kW-class, high-voltage power delivery systems from an SPG to an electric thruster system; (d) autonomous rendezvous and docking technology for in-space assembly of modular, reconfigurable spacecraft; (e) robotic assembly of modular space systems; and (f) modular, reconfigurable distributed avionics technologies. Maturation of these technologies was to be implemented through a series of increasingly-inclusive laboratory demonstrations that would have integrated and demonstrated two systems-of-systems: (a) the autonomous rendezvous and docking of modular spacecraft with deployable structures, robotic assembly, reconfiguration both during assembly and (b) the development and integration of an advanced thermal heat pipe and a high-voltage power delivery system with a representative lightweight high-voltage SPG array. In addition, an integrated simulation testbed would have been developed containing software models representing the technologies being matured in the laboratory demos. The testbed would have also included models for non-MRHE developed subsystems such as electric propulsion, so that end-to-end performance could have been assessed. This paper presents an overview of the MRHE Phase I activities at MSFC and its contractor partners. One of the major Phase I accomplishments is the assembly demonstration in the Lockheed Martin Advanced Technology Center (LMATC) Robot-Satellite facility, in which three robot-satellites successfully demonstrated rendezvous & docking, self-assembly, reconfiguration, adaptable GN&C, deployment, and interfaces between modules. Phase I technology maturation results from ENTECH include material recommendations for radiation hardened Stretched Lens Array (SLA) concentrator lenses, and a design concept and test results for a hi-voltage PV receiver. UAH's accomplishments include Supertube heatpipe test results, which support estimates of thermal conductivities at 30,000 times that of an equivalent silver rod. MSFC performed systems trades and developed a preliminary concept design for a 100kW-class modular reconfigurable solar electric propulsion transport vehicle, and Boeing Phantom Works in Huntsville performed assembly and rendezvous and docking trades. A concept animation video was produced by SAIC, wllich showed rendezvous and docking and SLA-square-rigger deployment in LEO.

Self-assembling toxin-based nanoparticles as self-delivered antitumoral drugs.

PubMed

Sánchez-García, Laura; Serna, Naroa; Álamo, Patricia; Sala, Rita; Céspedes, María Virtudes; Roldan, Mònica; Sánchez-Chardi, Alejandro; Unzueta, Ugutz; Casanova, Isolda; Mangues, Ramón; Vázquez, Esther; Villaverde, Antonio

2018-03-28

Loading capacity and drug leakage from vehicles during circulation in blood is a major concern when developing nanoparticle-based cell-targeted cytotoxics. To circumvent this potential issue it would be convenient the engineering of drugs as self-delivered nanoscale entities, devoid of any heterologous carriers. In this context, we have here engineered potent protein toxins, namely segments of the diphtheria toxin and the Pseudomonas aeruginosa exotoxin as self-assembling, self-delivered therapeutic materials targeted to CXCR4 + cancer stem cells. The systemic administration of both nanostructured drugs in a colorectal cancer xenograft mouse model promotes efficient and specific local destruction of target tumor tissues and a significant reduction of the tumor volume. This observation strongly supports the concept of intrinsically functional protein nanoparticles, which having a dual role as drug and carrier, are designed to be administered without the assistance of heterologous vehicles. Copyright © 2018 Elsevier B.V. All rights reserved.

Advanced composite elevator for Boeing 727 aircraft, volume 2

NASA Technical Reports Server (NTRS)

Chovil, D. V.; Grant, W. D.; Jamison, E. S.; Syder, H.; Desper, O. E.; Harvey, S. T.; Mccarty, J. E.

1980-01-01

Preliminary design activity consisted of developing and analyzing alternate design concepts and selecting the optimum elevator configuration. This included trade studies in which durability, inspectability, producibility, repairability, and customer acceptance were evaluated. Preliminary development efforts consisted of evaluating and selecting material, identifying ancillary structural development test requirements, and defining full scale ground and flight test requirements necessary to obtain Federal Aviation Administration (FAA) certification. After selection of the optimum elevator configuration, detail design was begun and included basic configuration design improvements resulting from manufacturing verification hardware, the ancillary test program, weight analysis, and structural analysis. Detail and assembly tools were designed and fabricated to support a full-scope production program, rather than a limited run. The producibility development programs were used to verify tooling approaches, fabrication processes, and inspection methods for the production mode. Quality parts were readily fabricated and assembled with a minimum rejection rate, using prior inspection methods.

Microstructured elastomeric surfaces with reversible adhesion and examples of their use in deterministic assembly by transfer printing

PubMed Central

Kim, Seok; Wu, Jian; Carlson, Andrew; Jin, Sung Hun; Kovalsky, Anton; Glass, Paul; Liu, Zhuangjian; Ahmed, Numair; Elgan, Steven L.; Chen, Weiqiu; Ferreira, Placid M.; Sitti, Metin; Huang, Yonggang; Rogers, John A.

2010-01-01

Reversible control of adhesion is an important feature of many desired, existing, and potential systems, including climbing robots, medical tapes, and stamps for transfer printing. We present experimental and theoretical studies of pressure modulated adhesion between flat, stiff objects and elastomeric surfaces with sharp features of surface relief in optimized geometries. Here, the strength of nonspecific adhesion can be switched by more than three orders of magnitude, from strong to weak, in a reversible fashion. Implementing these concepts in advanced stamps for transfer printing enables versatile modes for deterministic assembly of solid materials in micro/nanostructured forms. Demonstrations in printed two- and three-dimensional collections of silicon platelets and membranes illustrate some capabilities. An unusual type of transistor that incorporates a printed gate electrode, an air gap dielectric, and an aligned array of single walled carbon nanotubes provides a device example. PMID:20858729

Coordination-Driven Syntheses of Compact Supramolecular Metallacycles toward Extended Metallo-organic Stacked Supramolecular Assemblies.

PubMed

Lescop, Christophe

2017-04-18

One important concept associated with supramolecular chemistry is supramolecular self-assembly, which deals with the way discrete individual components interact via intermolecular interactions in order to build, upon their spontaneous association, high order functional assemblies. The accumulation of these very simple and localized noncovalent interactions (such as H-bonding, dipole-dipole, hydrophobic/hydrophilic, van der Waals, π-π, π-CH, etc.) is ubiquitous in the complexity of natural systems (such as DNA, proteins, membranes, micelles, etc.). It can also be transposed to the directed synthesis of intricate artificial scaffolds, which have anticipated geometries and properties. Among the synthetic strategies based on this concept, coordination-driven supramolecular chemistry uses the robust, reversible, and directional metal-to-ligand coordinative bond to build discrete metallo-supramolecular architectures. Within the last two decades, coordination-driven supramolecular chemistry has proved to be one of the most powerful contemporary synthetic approaches and has provided a significant number of increasingly complex supramolecular assemblies, which have predetermined sizes and geometries. While much focus has been devoted to architectures bearing internal cavities for host-guest chemistry or to generate specific reactivity, particular attention can also be paid to compact supramolecular assemblies given that their specific structures are characterized by peculiar synthetic guiding rules as well as by alternative long-range self-assembling properties. This Account describes how a preassembled Cu I bimetallic clip bearing short intermetallic distances can be used as a U-shaped molecular clip to give general and versatile access to a large variety of original compact supramolecular metallacycles. When this Cu I precursor is reacted with various cyano-capped ditopic linkers that have increasing lengths and complexities, specific effects guiding the selective and straightforward syntheses of such compact supramolecular objects are highlighted. Whereas a subtle compromise between the length of the ditopic linkers and the steric bulk of the molecular clip appears to be a purely stereogeometric preliminary parameter to master, lateral interlinker interactions (π-π stacking interactions or aurophilic interactions depending on the nature of the internal cores of the linkers) can circumvent these constraints regardless of the length of the linkers and allow the selective formation of new compact supramolecular structures. Generally, such derivatives presented a strong tendency to self-assemble in the solid state due to inter-supramolecule interactions. This approach thus opens a new door toward molecular materials having an attractive solid state structure for potential applications related to charge carrier mobility and luminescence properties. These compact supramolecular assemblies can therefore be considered as original secondary binding units directing the predictive preparation of such extended networks. The on-purpose design of original building blocks bearing specific cores allowed the formation of new compact supramolecular metallacycles such as "U-shaped" π-stacked assemblies or "pseudodouble paracyclophanes". Similarly, the control of the secondary structure of one-dimensional coordination polymers alternating π-stacked compact supramolecular metallacycles was also conducted. The results that are discussed in this Account illustrate how the rational design of both preassembled polymetallic precursors bearing short intermetallic distances and ditopic linkers able to induce cumulative lateral weak interactions can implement the general synthetic guiding rules of coordination driven supramolecular chemistry. This opens perspectives to use such compact supramolecular assemblies as secondary building blocks for the design of long-range organized functional molecular materials that have predictable architectures and targeted properties.

Astronaut Ross Approaches Assembly Concept for Construction of Erectable Space Structure (ACCESS)

NASA Technical Reports Server (NTRS)

1999-01-01

The crew assigned to the STS-61B mission included Bryan D. O'Conner, pilot; Brewster H. Shaw, commander; Charles D. Walker, payload specialist; mission specialists Jerry L. Ross, Mary L. Cleave, and Sherwood C. Spring; and Rodolpho Neri Vela, payload specialist. Launched aboard the Space Shuttle Atlantis November 28, 1985 at 7:29:00 pm (EST), the STS-61B mission's primary payload included three communications satellites: MORELOS-B (Mexico); AUSSAT-2 (Australia); and SATCOM KU-2 (RCA Americom). Two experiments were conducted to test assembling erectable structures in space: EASE (Experimental Assembly of Structures in Extravehicular Activity), and ACCESS (Assembly Concept for Construction of Erectable Space Structure). In a joint venture between NASA/Langley Research Center in Hampton, Virginia, and the Marshall Space Flight Center (MSFC), EASE and ACCESS were developed and demonstrated at MSFC's Neutral Buoyancy Simulator (NBS). In this STS-61B onboard photo, astronaut Ross, perched on the Manipulator Foot Restraint (MFR) approaches the erected ACCESS. The primary objective of these experiments was to test the structural assembly concepts for suitability as the framework for larger space structures and to identify ways to improve the productivity of space construction.

STS-61B Astronaut Ross Works on Assembly Concept for Construction of Erectable Space Structure

NASA Technical Reports Server (NTRS)

1985-01-01

The crew assigned to the STS-61B mission included Bryan D. O'Conner, pilot; Brewster H. Shaw, commander; Charles D. Walker, payload specialist; mission specialists Jerry L. Ross, Mary L. Cleave, and Sherwood C. Spring; and Rodolpho Neri Vela, payload specialist. Launched aboard the Space Shuttle Atlantis November 28, 1985 at 7:29:00 pm (EST), the STS-61B mission's primary payload included three communications satellites: MORELOS-B (Mexico); AUSSAT-2 (Australia); and SATCOM KU-2 (RCA Americom). Two experiments were conducted to test assembling erectable structures in space: EASE (Experimental Assembly of Structures in Extravehicular Activity), and ACCESS (Assembly Concept for Construction of Erectable Space Structure). In a joint venture between NASA/Langley Research Center in Hampton, Virginia and the Marshall Space Flight Center (MSFC), EASE and ACCESS were developed and demonstrated at MSFC's Neutral Buoyancy Simulator (NBS). In this STS-61B onboard photo astronaut Ross, located on the Manipulator Foot Restraint (MFR) over the cargo bay, erects ACCESS. The primary objective of this experiment was to test the structural assembly concepts for suitability as the framework for larger space structures and to identify ways to improve the productivity of space construction.

Ross Works on the Assembly Concept for Construction of Erectable Space Structure (ACCESS) During

NASA Technical Reports Server (NTRS)

1985-01-01

The crew assigned to the STS-61B mission included Bryan D. O'Conner, pilot; Brewster H. Shaw, commander; Charles D. Walker, payload specialist; mission specialists Jerry L. Ross, Mary L. Cleave, and Sherwood C. Spring; and Rodolpho Neri Vela, payload specialist. Launched aboard the Space Shuttle Atlantis November 28, 1985 at 7:29:00 pm (EST), the STS-61B mission's primary payload included three communications satellites: MORELOS-B (Mexico); AUSSAT-2 (Australia); and SATCOM KU-2 (RCA Americom). Two experiments were conducted to test assembling erectable structures in space: EASE (Experimental Assembly of Structures in Extravehicular Activity), and ACCESS (Assembly Concept for Construction of Erectable Space Structure). In a joint venture between NASA/Langley Research Center in Hampton, Virginia, and the Marshall Space Flight Center (MSFC), EASE and ACCESS were developed and demonstrated at MSFC's Neutral Buoyancy Simulator (NBS). In this STS-61B onboard photo, astronaut Ross works on ACCESS high above the orbiter. The primary objective of these experiments was to test the structural assembly concepts for suitability as the framework for larger space structures and to identify ways to improve the productivity of space construction.

Conceptual design of a self-deployable, high performance parabolic concentrator for advanced solar-dynamic power systems

NASA Astrophysics Data System (ADS)

Dehne, Hans J.

1991-05-01

NASA has initiated technology development programs to develop advanced solar dynamic power systems and components for space applications beyond 2000. Conceptual design work that was performed is described. The main efforts were the: (1) conceptual design of self-deploying, high-performance parabolic concentrator; and (2) materials selection for a lightweight, shape-stable concentrator. The deployment concept utilizes rigid gore-shaped reflective panels. The assembled concentrator takes an annular shape with a void in the center. This deployable concentrator concept is applicable to a range of solar dynamic power systems of 25 kW sub e to in excess of 75 kW sub e. The concept allows for a family of power system sizes all using the same packaging and deployment technique. The primary structural material selected for the concentrator is a polyethyl ethylketone/carbon fiber composite also referred to as APC-2 or Vitrex. This composite has a nearly neutral coefficient of thermal expansion which leads to shape stable characteristics under thermal gradient conditions. Substantial efforts were undertaken to produce a highly specular surface on the composite. The overall coefficient of thermal expansion of the composite laminate is near zero, but thermally induced stresses due to micro-movement of the fibers and matrix in relation to each other cause the surface to become nonspecular.

Conceptual design of a self-deployable, high performance parabolic concentrator for advanced solar-dynamic power systems

NASA Technical Reports Server (NTRS)

Dehne, Hans J.

1991-01-01

NASA has initiated technology development programs to develop advanced solar dynamic power systems and components for space applications beyond 2000. Conceptual design work that was performed is described. The main efforts were the: (1) conceptual design of self-deploying, high-performance parabolic concentrator; and (2) materials selection for a lightweight, shape-stable concentrator. The deployment concept utilizes rigid gore-shaped reflective panels. The assembled concentrator takes an annular shape with a void in the center. This deployable concentrator concept is applicable to a range of solar dynamic power systems of 25 kW sub e to in excess of 75 kW sub e. The concept allows for a family of power system sizes all using the same packaging and deployment technique. The primary structural material selected for the concentrator is a polyethyl ethylketone/carbon fiber composite also referred to as APC-2 or Vitrex. This composite has a nearly neutral coefficient of thermal expansion which leads to shape stable characteristics under thermal gradient conditions. Substantial efforts were undertaken to produce a highly specular surface on the composite. The overall coefficient of thermal expansion of the composite laminate is near zero, but thermally induced stresses due to micro-movement of the fibers and matrix in relation to each other cause the surface to become nonspecular.

Applying a Stitched, Rod-Stiffened Concept to Heavily Loaded Structure

NASA Technical Reports Server (NTRS)

Jegley, Dawn C.

2013-01-01

NASA and the Boeing Company have worked to develop new low-cost, light-weight composite structures for aircraft. A stitched carbon-epoxy material system was developed to reduce the weight and cost of transport aircraft wing structure, first in the NASA Advanced Composites Technology (ACT) program in the 1990's and now in the Environmentally Responsible Aviation (ERA) Project. By stitching through the thickness of a dry carbon fiber material prior to cure, the labor associated with panel fabrication and assembly can be significantly reduced and the need for mechanical fasteners is almost eliminated. Stitching provides the benefit of reducing or eliminating delaminations, including those between stiffener flanges and skin. Stitching also reduces part count, and therefore, cost of the structure. The stitched panel concept used in the ACT program in the 1990's used simple blade-stiffeners as stringers, caps and clips. Today, the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) concept is being developed for application to advanced vehicle configurations. PRSEUS provides additional weight savings through the use of a stiffener with a thin web and a unidirectional carbon rod at the top of the web which provides structurally efficient stiffening. A comparison between the blade-stiffened structure and PRSEUS is presented focusing on highly loaded structure and demonstrating improved weight reduction.

WRAP-RIB antenna technology development

NASA Technical Reports Server (NTRS)

Freeland, R. E.; Garcia, N. F.; Iwamoto, H.

1985-01-01

The wrap-rib deployable antenna concept development is based on a combination of hardware development and testing along with extensive supporting analysis. The proof-of-concept hardware models are large in size so they will address the same basic problems associated with the design fabrication, assembly and test as the full-scale systems which were selected to be 100 meters at the beginning of the program. The hardware evaluation program consists of functional performance tests, design verification tests and analytical model verification tests. Functional testing consists of kinematic deployment, mesh management and verification of mechanical packaging efficiencies. Design verification consists of rib contour precision measurement, rib cross-section variation evaluation, rib materials characterizations and manufacturing imperfections assessment. Analytical model verification and refinement include mesh stiffness measurement, rib static and dynamic testing, mass measurement, and rib cross-section characterization. This concept was considered for a number of potential applications that include mobile communications, VLBI, and aircraft surveillance. In fact, baseline system configurations were developed by JPL, using the appropriate wrap-rib antenna, for all three classes of applications.

Self-assembling segmented coiled tubing

DOEpatents

Raymond, David W.

2016-09-27

Self-assembling segmented coiled tubing is a concept that allows the strength of thick-wall rigid pipe, and the flexibility of thin-wall tubing, to be realized in a single design. The primary use is for a drillstring tubular, but it has potential for other applications requiring transmission of mechanical loads (forces and torques) through an initially coiled tubular. The concept uses a spring-loaded spherical `ball-and-socket` type joint to interconnect two or more short, rigid segments of pipe. Use of an optional snap ring allows the joint to be permanently made, in a `self-assembling` manner.

Designing topological defects in 2D materials using scanning probe microscopy and a self-healing mechanism: a density functional-based molecular dynamics study

NASA Astrophysics Data System (ADS)

Popov, Igor; Đurišić, Ivana; Belić, Milivoj R.

2017-12-01

Engineering of materials at the atomic level is one of the most important aims of nanotechnology. The unprecedented ability of scanning probe microscopy to address individual atoms opened up the possibilities for nanomanipulation and nanolitography of surfaces and later on of two-dimensional materials. While the state-of-the-art scanning probe lithographic methods include, primarily, adsorption, desorption and repositioning of adatoms and molecules on substrates or tailoring nanoribbons by etching of trenches, the precise modification of the intrinsic atomic structure of materials is yet to be advanced. Here we introduce a new concept, scanning probe microscopy with a rotating tip, for engineering of the atomic structure of membranes based on two-dimensional materials. In order to indicate the viability of the concept, we present our theoretical research, which includes atomistic modeling, molecular dynamics simulations, Fourier analysis and electronic transport calculations. While stretching can be employed for fabrication of atomic chains only, our comprehensive molecular dynamics simulations indicate that nanomanipulation by scanning probe microscopy with a rotating tip is capable of assembling a wide range of topological defects in two-dimensional materials in a rather controllable and reproducible manner. We analyze two possibilities. In the first case the probe tip is retracted from the membrane while in the second case the tip is released beneath the membrane allowing graphene to freely relax and self-heal the pore made by the tip. The former approach with the tip rotation can be achieved experimentally by rotation of the sample, which is equivalent to rotation of the tip, whereas irradiation of the membrane by nanoclusters can be utilized for the latter approach. The latter one has the potential to yield a yet richer diversity of topological defects on account of a lesser determinacy. If successfully realized experimentally the concept proposed here could be an important step toward controllable nanostructuring of two-dimensional materials.

Designing topological defects in 2D materials using scanning probe microscopy and a self-healing mechanism: a density functional-based molecular dynamics study.

PubMed

Popov, Igor; Đurišić, Ivana; Belić, Milivoj R

2017-12-08

Engineering of materials at the atomic level is one of the most important aims of nanotechnology. The unprecedented ability of scanning probe microscopy to address individual atoms opened up the possibilities for nanomanipulation and nanolitography of surfaces and later on of two-dimensional materials. While the state-of-the-art scanning probe lithographic methods include, primarily, adsorption, desorption and repositioning of adatoms and molecules on substrates or tailoring nanoribbons by etching of trenches, the precise modification of the intrinsic atomic structure of materials is yet to be advanced. Here we introduce a new concept, scanning probe microscopy with a rotating tip, for engineering of the atomic structure of membranes based on two-dimensional materials. In order to indicate the viability of the concept, we present our theoretical research, which includes atomistic modeling, molecular dynamics simulations, Fourier analysis and electronic transport calculations. While stretching can be employed for fabrication of atomic chains only, our comprehensive molecular dynamics simulations indicate that nanomanipulation by scanning probe microscopy with a rotating tip is capable of assembling a wide range of topological defects in two-dimensional materials in a rather controllable and reproducible manner. We analyze two possibilities. In the first case the probe tip is retracted from the membrane while in the second case the tip is released beneath the membrane allowing graphene to freely relax and self-heal the pore made by the tip. The former approach with the tip rotation can be achieved experimentally by rotation of the sample, which is equivalent to rotation of the tip, whereas irradiation of the membrane by nanoclusters can be utilized for the latter approach. The latter one has the potential to yield a yet richer diversity of topological defects on account of a lesser determinacy. If successfully realized experimentally the concept proposed here could be an important step toward controllable nanostructuring of two-dimensional materials.

Static Electricity-Responsive Supramolecular Assembly.

PubMed

Jintoku, Hirokuni; Ihara, Hirotaka; Matsuzawa, Yoko; Kihara, Hideyuki

2017-12-01

Stimuli-responsive materials can convert between molecular scale and macroscopic scale phenomena. Two macroscopic static electricity-responsive phenomena based on nanoscale supramolecular assemblies of a zinc porphyrin derivative are presented. One example involves the movement of supramolecular assemblies in response to static electricity. The assembly of a pyridine (Py) complex of the above-mentioned derivative in cyclohexane is drawn to a positively charged material, whereas the assembly of a 3,5-dimethylpyridine complex is drawn to a negatively charged material. The second phenomenon involves the movement of a non-polar solvent in response to static electrical stimulation. A cyclohexane solution containing a small quantity of the Py-complexed assembly exhibited a strong movement response towards negatively charged materials. Based on spectroscopic measurements and electron microscope observations, it was revealed that the assembled formation generates the observed response to static electricity. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Onsite Fabrication of Trusses and Structures

NASA Technical Reports Server (NTRS)

Bodle, J. G.; Browning, D. L.; Fisher, J. G.; Hujsak, E. J.; Kleidon, E. H.; Siden, L. E.; Tremblay, G. A.

1982-01-01

Tribeam truss that is strong and light made at site where used. Reinforced plastic members are fabricated by beam-making machine and assembled by assembly and welding machines. Although proposed for space-platform assembly, concept may be useful in terrestrial applications in remote or inaccessible places.

Results of EVA/mobile transporter space station truss assembly tests

NASA Technical Reports Server (NTRS)

Watson, Judith J.; Heard, Walter L., Jr.; Bush, Harold G.; Lake, M. S.; Jensen, J. K.; Wallsom, R. E.; Phelps, J. E.

1988-01-01

Underwater neutral buoyance tests were conducted to evaluate the use of a Mobile Transporter concept in conjunction with EVA astronauts to construct the Space Station Freedom truss structure. A three-bay orthogonal tetrahedral truss configuration with a 15 foot square cross section was repeatedly assembled by a single pair of pressure suited test subjects working from the Mobile Transporter astronaut positioning devices (mobile foot restraints). The average unit assembly time (which included integrated installation of utility trays) was 27.6 s/strut, or 6 min/bay. The results of these tests indicate that EVA assembly of space station size structures can be significantly enhanced when using a Mobile Transporter equipped with astronaut positioning devices. Rapid assembly time can be expected and are dependent primarily on the rate of translation permissible for on-orbit operations. The concept used to demonstate integrated installation of utility trays requires minimal EVA handling and consequentially, as the results show, has little impact on overall assembly time.

AHTR Mechanical, Structural, And Neutronic Preconceptual Design

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

Varma, Venugopal Koikal; Holcomb, David Eugene; Peretz, Fred J

2012-10-01

This report provides an overview of the mechanical, structural, and neutronic aspects of the Advanced High Temperature Reactor (AHTR) design concept. The AHTR is a design concept for a large output Fluoride salt cooled High-temperature Reactor (FHR) that is being developed to enable evaluation of the technology hurdles remaining to be overcome prior to FHRs becoming a commercial reactor class. This report documents the incremental AHTR design maturation performed over the past year and is focused on advancing the design concept to a level of a functional, self-consistent system. The AHTR employs plate type coated particle fuel assemblies with rapid,more » off-line refueling. Neutronic analysis of the core has confirmed the viability of a 6-month 2-batch cycle with 9 weight-percent enriched uranium fuel. Refueling is intended to be performed automatically under visual guidance using dedicated robotic manipulators. The present design intent is for used fuel to be stored inside of containment for at least 6 months and then transferred to local dry wells for intermediate term, on-site storage. The mechanical and structural concept development effort has included an emphasis on transportation and constructability to minimize construction costs and schedule. The design intent is that all components be factory fabricated into rail transportable modules that are assembled into subsystems at an on-site workshop prior to being lifted into position using a heavy-lift crane in an open-top style construction. While detailed accident identification and response sequence analysis has yet to be performed, the design concept incorporates multiple levels of radioactive material containment including fully passive responses to all identified design basis or non-very-low frequency beyond design basis accidents. Key building design elements include: 1) below grade siting to minimize vulnerability to aircraft impact, 2) multiple natural circulation decay heat rejection chimneys, 3) seismic base isolation, and 4) decay heat powered back-up electricity generation. The report provides a preconceptual design of the manipulators, the fuel transfer system, and the salt transfer loops. The mechanical handling of the fuel and how it is accomplished without instrumentation inside the salt is described within the report. All drives for the manipulators reside outside the reactor top flange. The design has also taken into account the transportability of major components and how they will be assembled on site« less

A mobile transporter concept for EVA assembly of future spacecraft

NASA Technical Reports Server (NTRS)

Watson, Judith J.; Bush, Harold G.; Heard, Walter L., Jr.; Lake, Mark S.; Jensen, J. Kermit

1990-01-01

This paper details the ground test program for the NASA Langley Research Center Mobile Transporter concept. The Mobile Transporter would assist EVA astronauts in the assembly of the Space Station Freedom. 1-g and simulated O-g (neutral buoyancy) tests were conducted to evaluate the use of the Mobile Transporter. A three-bay (44 struts) orthogonal tetrahedral truss configuration with a 15-foot-square cross section was repeatedly assembled by a single pair of pressure suited test subjects working from the Mobile Transporter astronaut positioning devices. The average unit assembly time was 28 seconds/strut. The results of these tests indicate that the use of a Mobile Transporter for EVA assembly of Space Station size structure is viable and practical. Additionally, the Mobile Transporter could be used to construct other spacecraft such as the submillimeter astronomical laboratory, space crane, and interplanetary (i.e., Mars and lunar) spacecraft.

Investigation of a Bio-Inspired Liner Concept

NASA Technical Reports Server (NTRS)

Koch, L. Danielle

2017-01-01

Four samples of natural reeds, Phragmites australis, were tested in the NASA Langley and Glenn Normal Incidence Impedance Tubes in order to experimentally determine the acoustic absorption coefficients as a function of frequency from 400 to 3000 Hz. Six samples that mimicked the geometry of the assemblies of natural reeds were also designed and additively manufactured from ASA thermoplastic and tested. Results indicate that structures can be manufactured of synthetic materials that mimic the geometry and the low frequency acoustic absorption of natural reeds. This accomplishment demonstrates that a new class of structures can now be considered for a wide range of industrial products that need thin, lightweight, broadband acoustic absorption effective at frequencies below 1000 Hz. Aircraft engine acoustic liners and aircraft cabin acoustic liners, in particular, are two aviation applications that might benefit from further development of this concept.

A gas flow indicator for portable life support systems

NASA Technical Reports Server (NTRS)

Bass, R. L., III; Schroeder, E. C.

1975-01-01

A three-part program was conducted to develop a gas flow indicator (GFI) to monitor ventilation flow in a portable life support system. The first program phase identified concepts which could potentially meet the GFI requirements. In the second phase, a working breadboard GFI, based on the concept of a pressure sensing diaphragm-aneroid assembly connected to a venturi, was constructed and tested. Extensive testing of the breadboard GFI indicated that the design would meet all NASA requirements including eliminating problems experienced with the ventilation flow sensor used in the Apollo program. In the third program phase, an optimized GFI was designed by utilizing test data obtained on the breadboard unit. A prototype unit was constructed using prototype materials and fabrication techniques, and performance tests indicated that the prototype GFI met or exceeded all requirements.

Magnetically attached sputter targets

DOEpatents

Makowiecki, D.M.; McKernan, M.A.

1994-02-15

An improved method and assembly for attaching sputtering targets to cathode assemblies of sputtering systems which includes a magnetically permeable material is described. The magnetically permeable material is imbedded in a target base that is brazed, welded, or soldered to the sputter target, or is mechanically retained in the target material. Target attachment to the cathode is achieved by virtue of the permanent magnets and/or the pole pieces in the cathode assembly that create magnetic flux lines adjacent to the backing plate, which strongly attract the magnetically permeable material in the target assembly. 11 figures.

Magnetically attached sputter targets

DOEpatents

Makowiecki, Daniel M.; McKernan, Mark A.

1994-01-01

An improved method and assembly for attaching sputtering targets to cathode assemblies of sputtering systems which includes a magnetically permeable material. The magnetically permeable material is imbedded in a target base that is brazed, welded, or soldered to the sputter target, or is mechanically retained in the target material. Target attachment to the cathode is achieved by virtue of the permanent magnets and/or the pole pieces in the cathode assembly that create magnetic flux lines adjacent to the backing plate, which strongly attract the magnetically permeable material in the target assembly.

Advances in crash dynamics for aircraft safety

NASA Astrophysics Data System (ADS)

Guida, M.; Marulo, F.; Abrate, S.

2018-04-01

This paper studies the ability of the fuselage's lower lobe to absorb the energy during a crash landing, where the introduction of the composite materials can improve the crash survivability thanks to the crushing capability of structural parts to limit the effects of deceleration on the occupants. Providing a protective shell around the occupants and minimizing the risks of injuries during and immediately after the crash in the post-crash regime is a safety requirement. This study consists of: (1) numerical and experimental investigations on small components to verify design concepts using high performance composite materials; (2) analyses of full scale crashes of fuselage lower lobes. This paper outlines an approach for demonstrating the crashworthiness characteristics of the airframe performing a drop test at low velocity impact to validate a numerical model obtained by assembling structural components and materials' properties previously obtained by testing coupons and sub-elements.

Thermal Peak Management Using Organic Phase Change Materials for Latent Heat Storage in Electronic Applications

PubMed Central

Maxa, Jacob; Novikov, Andrej; Nowottnick, Mathias

2017-01-01

Modern high power electronics devices consists of a large amount of integrated circuits for switching and supply applications. Beside the benefits, the technology exhibits the problem of an ever increasing power density. Nowadays, heat sinks that are directly mounted on a device, are used to reduce the on-chip temperature and dissipate the thermal energy to the environment. This paper presents a concept of a composite coating for electronic components on printed circuit boards or electronic assemblies that is able to buffer a certain amount of thermal energy, dissipated from a device. The idea is to suppress temperature peaks in electronic components during load peaks or electronic shorts, which otherwise could damage or destroy the device, by using a phase change material to buffer the thermal energy. The phase change material coating could be directly applied on the chip package or the PCB using different mechanical retaining jigs.

In-Space Assembly Capability Assessment for Potential Human Exploration and Science Applications

NASA Technical Reports Server (NTRS)

Jefferies, Sharon A.; Jones, Christopher A.; Arney, Dale C.; Stillwagen, Frederic H.; Chai, Patrick R.; Hutchinson, Craig D.; Stafford, Matthew A.; Moses, Robert W.; Dempsey, James A.; Rodgers, Erica M.;

DNA-nanoparticle assemblies go organic: Macroscopic polymeric materials with nanosized features

PubMed Central

2012-01-01

Background One of the goals in the field of structural DNA nanotechnology is the use of DNA to build up 2- and 3-D nanostructures. The research in this field is motivated by the remarkable structural features of DNA as well as by its unique and reversible recognition properties. Nucleic acids can be used alone as the skeleton of a broad range of periodic nanopatterns and nanoobjects and in addition, DNA can serve as a linker or template to form DNA-hybrid structures with other materials. This approach can be used for the development of new detection strategies as well as nanoelectronic structures and devices. Method Here we present a new method for the generation of unprecedented all-organic conjugated-polymer nanoparticle networks guided by DNA, based on a hierarchical self-assembly process. First, microphase separation of amphiphilic block copolymers induced the formation of spherical nanoobjects. As a second ordering concept, DNA base pairing has been employed for the controlled spatial definition of the conjugated-polymer particles within the bulk material. These networks offer the flexibility and the diversity of soft polymeric materials. Thus, simple chemical methodologies could be applied in order to tune the network's electrical, optical and mechanical properties. Results and conclusions One- two- and three-dimensional networks have been successfully formed. Common to all morphologies is the integrity of the micelles consisting of DNA block copolymer (DBC), which creates an all-organic engineered network. PMID:22646980

Self-Assembly: How Nature Builds

ERIC Educational Resources Information Center

Jones, M. Gail; Falvo, Michael R.; Broadwell, Bethany; Dotger, Sharon

2006-01-01

Self-assembly or spontaneous assembly is a process in which materials build themselves without assistance. This process plays a central role in the construction of biological structures and materials such as cells, viruses, and bone, and also in abiotic processes like phase transitions and crystal formation. The principles of self-assembly help…

Electrolysis Performance Improvement Concept Study (EPICS) flight experiment phase C/D

NASA Technical Reports Server (NTRS)

Schubert, F. H.; Lee, M. G.

1995-01-01

The overall purpose of the Electrolysis Performance Improvement Concept Study flight experiment is to demonstrate and validate in a microgravity environment the Static Feed Electrolyzer concept as well as investigate the effect of microgravity on water electrolysis performance. The scope of the experiment includes variations in microstructural characteristics of electrodes and current densities in a static feed electrolysis cell configuration. The results of the flight experiment will be used to improve efficiency of the static feed electrolysis process and other electrochemical regenerative life support processes by reducing power and expanding the operational range. Specific technologies that will benefit include water electrolysis for propulsion, energy storage, life support, extravehicular activity, in-space manufacturing and in-space science in addition to other electrochemical regenerative life support technologies such as electrochemical carbon dioxide and oxygen separation, electrochemical oxygen compression and water vapor electrolysis. The Electrolysis Performance Improvement Concept Study flight experiment design incorporates two primary hardware assemblies: the Mechanical/Electrochemical Assembly and the Control/Monitor Instrumentation. The Mechanical/Electrochemical Assembly contains three separate integrated electrolysis cells along with supporting pressure and temperature control components. The Control/Monitor Instrumentation controls the operation of the experiment via the Mechanical/Electrochemical Assembly components and provides for monitoring and control of critical parameters and storage of experimental data.

A review of the promises and challenges of micro-concentrator photovoltaics

NASA Astrophysics Data System (ADS)

Domínguez, César; Jost, Norman; Askins, Steve; Victoria, Marta; Antón, Ignacio

2017-09-01

Micro concentrator photovoltaics (micro-CPV) is an unconventional approach for developing high-efficiency low-cost PV systems. The micrifying of cells and optics brings about an increase of efficiency with respect to classical CPV, at the expense of some fundamental challenges at mass production. The large costs linked to miniaturization under conventional serial-assembly processes raise the need for the development of parallel manufacturing technologies. In return, the tiny sizes involved allows exploring unconventional optical architectures or revisiting conventional concepts that were typically discarded because of large material consumption or high bulk absorption at classical CPV sizes.

Cost Estimate for Molybdenum and Tantalum Refractory Metal Alloy Flow Circuit Concepts

NASA Technical Reports Server (NTRS)

Hickman, Robert R.; Martin, James J.; Schmidt, George R.; Godfroy, Thomas J.; Bryhan, A.J.

2010-01-01

The Early Flight Fission-Test Facilities (EFF-TF) team at NASA Marshall Space Flight Center (MSFC) has been tasked by the Naval Reactors Prime Contract Team (NRPCT) to provide a cost and delivery rough order of magnitude estimate for a refractory metal-based lithium (Li) flow circuit. The design is based on the stainless steel Li flow circuit that is currently being assembled for an NRPCT task underway at the EFF-TF. While geometrically the flow circuit is not representative of a final flight prototype, knowledge has been gained to quantify (time and cost) the materials, manufacturing, fabrication, assembly, and operations to produce a testable configuration. This Technical Memorandum (TM) also identifies the following key issues that need to be addressed by the fabrication process: Alloy selection and forming, cost and availability, welding, bending, machining, assembly, and instrumentation. Several candidate materials were identified by NRPCT including molybdenum (Mo) alloy (Mo-47.5 %Re), tantalum (Ta) alloys (T-111, ASTAR-811C), and niobium (Nb) alloy (Nb-1 %Zr). This TM is focused only on the Mo and Ta alloys, since they are of higher concern to the ongoing effort. The initial estimate to complete a Mo-47%Re system ready for testing is =$9,000k over a period of 30 mo. The initial estimate to complete a T-111 or ASTAR-811C system ready for testing is =$12,000k over a period of 36 mo.

Novel Round Energy Director for Use with Servo-driven Ultrasonic Welder

NASA Astrophysics Data System (ADS)

Savitski, Alex; Klinstein, Leo; Holt, Kenneth

Increasingly stringent process repeatability and precision of assembly requirements are common for high-volume manufacturing for electronic, automotive and especially medical device industries, in which components for disposable medication delivery devices are produced in hundreds of millions annually. Ultrasonic welding, one of the most efficient of plastic welding processes often joins these small plastic parts together, and quite possibly, the one most broadly adopted for high volume assembly. The very fundamental factor in ultrasonic welding process performance is a proper joint design, the most common of which is a design utilizing an energy director. Keeping the energy director size and shape consistent on a part-to-part basis in high volume, multi-cavity operations presents a constant challenge to molded part vendors, as dimensional variations from cavity to cavity and variations in the molding process are always present. A newly developed concept of energy director design, when the tip of the energy director is round, addresses these problems, as the round energy director is significantly easier to mold and maintain its dimensional consistency. It also eliminates a major source of process variability for assembly operations. Materializing the benefits of new type of joint design became possible with the introduction of servo-driven ultrasonic welders, which allow an unprecedented control of material flow during the welding cycle and results in significantly improved process repeatability. This article summarizes results of recent studies focused on evaluating performance of round energy director and investigating the main factors responsible for the joint quality.

All-Iron Redox Flow Battery Tailored for Off-Grid Portable Applications.

PubMed

Tucker, Michael C; Phillips, Adam; Weber, Adam Z

2015-12-07

An all-iron redox flow battery is proposed and developed for end users without access to an electricity grid. The concept is a low-cost battery which the user assembles, discharges, and then disposes of the active materials. The design goals are: (1) minimize upfront cost, (2) maximize discharge energy, and (3) utilize non-toxic and environmentally benign materials. These are different goals than typically considered for electrochemical battery technology, which provides the opportunity for a novel solution. The selected materials are: low-carbon-steel negative electrode, paper separator, porous-carbon-paper positive electrode, and electrolyte solution containing 0.5 m Fe2 (SO4 )3 active material and 1.2 m NaCl supporting electrolyte. With these materials, an average power density around 20 mW cm(-2) and a maximum energy density of 11.5 Wh L(-1) are achieved. A simple cost model indicates the consumable materials cost US$6.45 per kWh(-1) , or only US$0.034 per mobile phone charge. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

All-Iron Redox Flow Battery Tailored for Off-Grid Portable Applications

DOE PAGES

Tucker, Michael C.; Phillips, Adam; Weber, Adam Z.

2015-11-20

We proposed and developed an all-iron redox flow battery for end users without access to an electricity grid. The concept is a low-cost battery which the user assembles, discharges, and then disposes of the active materials. Our design goals are: (1) minimize upfront cost, (2) maximize discharge energy, and (3) utilize non-toxic and environmentally benign materials. These are different goals than typically considered for electrochemical battery technology, which provides the opportunity for a novel solution. The selected materials are: low-carbon-steel negative electrode, paper separator, porous-carbon-paper positive electrode, and electrolyte solution containing 0.5 m Fe 2 (SO 4 ) 3 activemore » material and 1.2 m NaCl supporting electrolyte. Furthermore, with these materials, an average power density around 20 mW cm -2 and a maximum energy density of 11.5 Wh L -1 are achieved. A simple cost model indicates the consumable materials cost US$6.45 per kWh -1 , or only US$0.034 per mobile phone charge.« less

Systems engineering studies of lunar base construction

NASA Technical Reports Server (NTRS)

Morgenthaler, George W.

1991-01-01

Many ingenious concepts have been proposed for lunar base construction, but few systematic studies exist which relate time-consistent lunar base construction technologies and the choice of lunar base approach with the long-term SEI objectives - i.e., lunar indigenous base construction and Mars Exploration equipment development. To fill this gap, CSC has taken a two-pronged approach. First, the Center undertook basic geotechnical investigations of lunar soil, fabrication of a scale prototype of a lunar construction crane, a multi-robot construction team laboratory experiment, and a preliminary design of lunar base structures. Second, during Jun. and Jul. 1991 two lunar base construction systems engineering studies were accomplished - a 'near term lunar base' study, and a 'far-term lunar base' study. The goals of these studies were to define the major lunar base construction research problems in consistent technology/construction frameworks, and to define design requirements for construction equipment such as a lunar crane and a regolith mover. The 'near-term lunar base' study examined three different construction concepts for a lunar base comprised of pre-fabricated, pre-tested, Space Station Freedom-type modules, which would be covered with regolith shielding. Concept A used a lunar crane for unloading and transportation; concept B, a winch and cart; and concept C, a walker to move the modules from the landing site to the base site and assemble them. To evaluate the merits of each approach, calculations were made of mass efficiency measure, source mass, reliability, far-term base mass, Mars base mass, and base assembly time. The model thus established was also used to define the requirements for crane speed and regolith mover m(sup 3)/sec rates. A major problem addressed is how to 'mine' the regolith and stack it over the habitats as shielding. To identify when the cost of using indigenous lunar materials to construct the base exceeds the cost of development and delivery of the equipment for processing lunar materials, a study of construction of a candidate sintered regolith 'far term lunar base' was undertaken. A technique was devised for casting slabs of sintered (basaltic) regolith and assembling these into a hemispherical (or geodesic) dome. The major problem occurs with the inner liner. At 14.7 psi and 20 percent oxygen internal atmosphere, the entire structure is in tension, even with the regolith load. Also, another study has indicated that at 14.7 psi major resupply of air will be needed because of leakage, and astronauts may have to engage in extensive pre-breathing and post-breathing for extravehicular activity (EVA) tasks, thus detracting from useful mission work time. An alternative is to operate part of the base at, say, 5 psi and 70 percent oxygen, or to equip the astronauts with hard suits at 8.3 psi or greater. All of these choices directly influence base design and construction techniques.

Two-stage optics - High-acuity performance from low-acuity optical systems

NASA Technical Reports Server (NTRS)

Meinel, Aden B.; Meinel, Marjorie P.

1992-01-01

The concept of two-stage optics, developed under a program to enhance the performance, lower the cost, and increase the reliability of the 20-m Large Deployable Telescope, is examined. The concept permits the large primary mirror to remain as deployed or as space-assembled, with phasing and subsequent control of the system done by a small fully assembled optical active element placed at an exit pupil. The technique is being applied to correction of the fabrication/testing error in the Hubble Space Telescope primary mirror. The advantages offered by this concept for very large space telescopes are discussed.

Designing learning apparatus to promote twelfth grade students’ understanding of digital technology concept: A preliminary studies

NASA Astrophysics Data System (ADS)

Marlius; Kaniawati, I.; Feranie, S.

2018-05-01

A preliminary learning design using relay to promote twelfth grade student’s understanding of logic gates concept is implemented to see how well it’s to adopted by six high school students, three male students and three female students of twelfth grade. This learning design is considered for next learning of digital technology concept i.e. data digital transmition and analog. This work is a preliminary study to design the learning for large class. So far just a few researches designing learning design related to digital technology with relay. It may due to this concept inserted in Indonesian twelfth grade curriculum recently. This analysis is focus on student difficulties trough video analysis to learn the concept. Based on our analysis, the recommended thing for redesigning learning is: students understand first about symbols and electrical circuits; the Student Worksheet is made in more detail on the assembly steps to the project board; mark with symbols at points in certain places in the circuit for easy assembly; assembly using relays by students is enough until is the NOT’s logic gates and the others that have been assembled so that effective time. The design of learning using relays can make the relay a liaison between the abstract on the digital with the real thing of it, especially in the circuit of symbols and real circuits. Besides it is expected to also enrich the ability of teachers in classroom learning about digital technology.

Container for radioactive materials

DOEpatents

Fields, Stanley R.

1985-01-01

A container for housing a plurality of canister assemblies containing radioactive material and disposed in a longitudinally spaced relation within a carrier to form a payload package concentrically mounted within the container. The payload package includes a spacer for each canister assembly, said spacer comprising a base member longitudinally spacing adjacent canister assemblies from each other and a sleeve surrounding the associated canister assembly for centering the same and conducting heat from the radioactive material in a desired flow path.

Novel oxygen atom source for material degradation studies

NASA Technical Reports Server (NTRS)

Krech, R. H.; Caledonia, G. E.

1988-01-01

Physical Sciences Inc. (PSI) has developed a high flux pulsed source of energetic (8 km/s) atomic oxygen to bombard specimens in experiments on the aging and degradation of materials in a low earth orbit environment. The proof-of-concept of the PSI approach was demonstrated in a Phase 1 effort. In Phase 2 a large O-atom testing device (FAST-2) has been developed and characterized. Quantitative erosion testing of materials, components, and even small assemblies (such as solar cell arrays) can be performed with this source to determine which materials and/or components are most vulnerable to atomic oxygen degradation. The source is conservatively rated to irradiate a 100 sq cm area sample at greater than 10(exp 17) atoms/s, at a 10 Hz pulse rate. Samples can be exposed to an atomic oxygen fluence equivalent to the on-orbit ram direction exposure levels incident on Shuttle surfaces at 250 km during a week-long mission in a few hours.

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

Zhang, Tianfu; Ma, Zhuang; Li, Guoping

Electrostatic self-assembly in organic solvent without intensively oxidative or corrosive environments, was adopted to prepare Al/Fe{sub 2}O{sub 3}/MWCNT nanostructured energetic materials as an energy generating material. The negatively charged MWCNT was used as a glue-like agent to direct the self-assembly of the well dispersed positively charged Al (fuel) and Fe{sub 2}O{sub 3} (oxide) nanoparticles. This spontaneous assembly method without any surfactant chemistry or other chemical and biological moieties decreased the aggregation of the same nanoparticles largely, moreover, the poor interfacial contact between the Al (fuel) and Fe{sub 2}O{sub 3} (oxide) nanoparticles was improved significantly, which was the key characteristic ofmore » high performance nanostructured energetic materials. In addition, the assembly process was confirmed as Diffusion-Limited Aggregation. The assembled Al/Fe{sub 2}O{sub 3}/MWCNT nanostructured energetic materials showed excellent performance with heat release of 2400 J/g, peak pressure of 0.42 MPa and pressurization rate of 105.71 MPa/s, superior to that in the control group Al/Fe{sub 2}O{sub 3} nanostructured energetic materials prepared by sonication with heat release of 1326 J/g, peak pressure of 0.19 MPa and pressurization rate of 33.33 MPa/s. Therefore, the approach, which is facile, opens a promising route to the high performance nanostructured energetic materials. - Graphical abstract: The negatively charged MWCNT was used as a glue-like agent to direct the self-assembly of the well dispersed positively charged Al (fuel) and Fe{sub 2}O{sub 3} (oxide) nanoparticles. - Highlights: • A facile spontaneous electrostatic assembly strategy without surfactant was adopted. • The fuels and oxidizers assembled into densely packed nanostructured composites. • The assembled nanostructured energetic materials have excellent performance. • This high performance energetic material can be scaled up for practical application. • This strategy can be applied into other nanostructured energetic material systems.« less

Component-Level Electronic-Assembly Repair (CLEAR) Operational Concept

NASA Technical Reports Server (NTRS)

Oeftering, Richard C.; Bradish, Martin A.; Juergens, Jeffrey R.; Lewis, Michael J.; Vrnak, Daniel R.

2011-01-01

This Component-Level Electronic-Assembly Repair (CLEAR) Operational Concept document was developed as a first step in developing the Component-Level Electronic-Assembly Repair (CLEAR) System Architecture (NASA/TM-2011-216956). The CLEAR operational concept defines how the system will be used by the Constellation Program and what needs it meets. The document creates scenarios for major elements of the CLEAR architecture. These scenarios are generic enough to apply to near-Earth, Moon, and Mars missions. The CLEAR operational concept involves basic assumptions about the overall program architecture and interactions with the CLEAR system architecture. The assumptions include spacecraft and operational constraints for near-Earth orbit, Moon, and Mars missions. This document addresses an incremental development strategy where capabilities evolve over time, but it is structured to prevent obsolescence. The approach minimizes flight hardware by exploiting Internet-like telecommunications that enables CLEAR capabilities to remain on Earth and to be uplinked as needed. To minimize crew time and operational cost, CLEAR exploits offline development and validation to support online teleoperations. Operational concept scenarios are developed for diagnostics, repair, and functional test operations. Many of the supporting functions defined in these operational scenarios are further defined as technologies in NASA/TM-2011-216956.

Concept for a fast analysis method of the energy dissipation at mechanical joints

NASA Astrophysics Data System (ADS)

Wolf, Alexander; Brosius, Alexander

2017-10-01

When designing hybrid parts and structures one major challenge is the design, production and quality assessment of the joining points. While the polymeric composites themselves have excellent material properties, the necessary joints are often the weak link in assembled structures. This paper presents a method of measuring and analysing the energy dissipation at mechanical joining points of hybrid parts. A simplified model is applied based on the characteristic response to different excitation frequencies and amplitudes. The dissipation from damage is the result of relative moments between joining partners und damaged fibres within the composite, whereas the visco-elastic material behaviour causes the intrinsic dissipation. The ambition is to transfer these research findings to the characterisation of mechanical joints in order to quickly assess the general quality of the joint with this non-destructive testing method. The inherent challenge for realising this method is the correct interpretation of the measured energy dissipation and its attribution to either a bad joining point or intrinsic material properties. In this paper the authors present the concept for energy dissipation measurements at different joining points. By inverse analysis a simplified fast semi-analytical model will be developed that allows for a quick basic quality assessment of a given joining point.

Modular cathode assemblies and methods of using the same for electrochemical reduction

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

Wiedmeyer, Stanley G.; Barnes, Laurel A.; Williamson, Mark A.

Modular cathode assemblies are useable in electrolytic reduction systems and include a basket through which fluid electrolyte may pass and exchange charge with a material to be reduced in the basket. The basket can be divided into upper and lower sections to provide entry for the material. Example embodiment cathode assemblies may have any shape to permit modular placement at any position in reduction systems. Modular cathode assemblies include a cathode plate in the basket, to which unique and opposite electrical power may be supplied. Example embodiment modular cathode assemblies may have standardized electrical connectors. Modular cathode assemblies may bemore » supported by a top plate of an electrolytic reduction system. Electrolytic oxide reduction systems are operated by positioning modular cathode and anode assemblies at desired positions, placing a material in the basket, and charging the modular assemblies to reduce the metal oxide.« less

Modular cathode assemblies and methods of using the same for electrochemical reduction

DOEpatents

Wiedmeyer, Stanley G; Barnes, Laurel A; Williamson, Mark A; Willit, James L

2014-12-02

Modular cathode assemblies are useable in electrolytic reduction systems and include a basket through which fluid electrolyte may pass and exchange charge with a material to be reduced in the basket. The basket can be divided into upper and lower sections to provide entry for the material. Example embodiment cathode assemblies may have any shape to permit modular placement at any position in reduction systems. Modular cathode assemblies include a cathode plate in the basket, to which unique and opposite electrical power may be supplied. Example embodiment modular cathode assemblies may have standardized electrical connectors. Modular cathode assemblies may be supported by a top plate of an electrolytic reduction system. Electrolytic oxide reduction systems are operated by positioning modular cathode and anode assemblies at desired positions, placing a material in the basket, and charging the modular assemblies to reduce the metal oxide.

Mechanics and Physics of Solids, Uncertainy, and the Archetype-Genome Exemplar

NASA Astrophysics Data System (ADS)

Greene, M. Steven

This dissertation argues that the mechanics and physics of solids rely on a fundamental exemplar: the apparent properties of a system depend on the building blocks that comprise it. Building blocks are referred to as archetypes and apparent system properties as the system genome. Three entities are of importance: the archetype properties, the conformation of archetypes, and the properties of interactions activated by that conformation. The combination of these entities into the system genome is called assembly. To show the utility of the archetype-genome exemplar, the dissertation presents the mathematical construction and computational implementation of a new theory for solid mechanics that is a continuum manifestation of the assembly process. The so-called archetype-blending continuum theory aligns the form of globally valid balance laws with physics evolving in a material's composite constitutive response so that, by rethinking conventional micromechanics, the theory accounts naturally for each piece of the genome assembly triplet: archetypes, interactions, and their conformation. With the pieces of the triplet isolated in the theory, materials genome design concepts that separately control microstructure and property may be gleaned from exploration of the constitutive parameter space. A suite of simulations that apply the new theory to polymer nanocomposite materials demonstrate the ability of the theory to predict a robust material genome that includes damping properties, modulus weakening, local strain amplification, and size effects. The dissertation also presents a theoretical assessment of the importance of uncertainty propagation in the archetype-genome exemplar. The findings from a set of computational experiments on instances of a general class of microstructured materials suggest that when overlap occurs between the size of the system geometry and the features of the conformation, material genomes become less certain. Increasing nonuniformity of boundary conditions and the size of random field correlation lengths exacerbate this conclusion. These criteria are combined into a scalar metric used to assess the impact of archetype-level uncertainties on the material genome for general scenarios in solid mechanics. Exemplary benchmark problems include bending in elastoplasticity and instability-induced pattern transition in porous elastomer. The contributions of this dissertation are threefold: (1) the mathematical construction of a new continuum theory for mechanics and physics of solids, (2) implementation of the theory, and (3) theoretical assessment of the scenarios in which material genomes deviate from determinism.

Nuclear reactor target assemblies, nuclear reactor configurations, and methods for producing isotopes, modifying materials within target material, and/or characterizing material within a target material

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

Toth, James J.; Wall, Donald; Wittman, Richard S.

Target assemblies are provided that can include a uranium-comprising annulus. The assemblies can include target material consisting essentially of non-uranium material within the volume of the annulus. Reactors are disclosed that can include one or more discrete zones configured to receive target material. At least one uranium-comprising annulus can be within one or more of the zones. Methods for producing isotopes within target material are also disclosed, with the methods including providing neutrons to target material within a uranium-comprising annulus. Methods for modifying materials within target material are disclosed as well as are methods for characterizing material within a targetmore » material.« less

Mixed Dimensional Van der Waals Heterostructures for Opto-Electronics.

NASA Astrophysics Data System (ADS)

Jariwala, Deep

The isolation of a growing number of two-dimensional (2D) materials has inspired worldwide efforts to integrate distinct 2D materials into van der Waals (vdW) heterostructures. While a tremendous amount of research activity has occurred in assembling disparate 2D materials into ``all-2D'' van der Waals heterostructures, this concept is not limited to 2D materials alone. Given that any passivated, dangling bond-free surface will interact with another via vdW forces, the vdW heterostructure concept can be extended to include the integration of 2D materials with non-2D materials that adhere primarily through noncovalent interactions. In the first part of this talk I will present our work on emerging mixed-dimensional (2D + nD, where n is 0, 1 or 3) heterostructure devices performed at Northwestern University. I will present two distinct examples of gate-tunable p-n heterojunctions 1. Single layer n-type MoS2\\ (2D) combined with p-type semiconducting single walled carbon nanotubes (1D) and 2. Single layer MoS2 combined with 0D molecular semiconductor, pentacene. I will present the unique electrical properties, underlying charge transport mechanisms and photocurrent responses in both the above systems using a variety of scanning probe microscopy techniques as well as computational analysis. This work shows that van der Waals interactions are robust across different dimensionalities of materials and can allow fabrication of semiconductor devices with unique geometries and properties unforeseen in bulk semiconductors. Finally, I will briefly discuss our recent work from Caltech on near-unity absorption in atomically-thin photovoltaic devices. This work is supported by the Materials Research Center at Northwestern University, funded by the National Science Foundation (NSF DMR-1121262) and the Resnick Sustainability Institute at Caltech.

Robotic space construction

NASA Technical Reports Server (NTRS)

Mixon, Randolph W.; Hankins, Walter W., III; Wise, Marion A.

1988-01-01

Research at Langley AFB concerning automated space assembly is reviewed, including a Space Shuttle experiment to test astronaut ability to assemble a repetitive truss structure, testing the use of teleoperated manipulators to construct the Assembly Concept for Construction of Erectable Space Structures I truss, and assessment of the basic characteristics of manipulator assembly operations. Other research topics include the simultaneous coordinated control of dual-arm manipulators and the automated assembly of candidate Space Station trusses. Consideration is given to the construction of an Automated Space Assembly Laboratory to study and develop the algorithms, procedures, special purpose hardware, and processes needed for automated truss assembly.

Construction concept for erecting an offset-fed antenna

NASA Technical Reports Server (NTRS)

Rhodes, M. D.

1984-01-01

A design concept for the construction of an offset-fed antenna is discussed. Antennas of this type are of interest for space applications because the configuration eliminates the effects of feed and feed-support blockage. The proposed construction concept is developed around the assembly of a stiff truss substructure by pressure-suited astronauts operating in extravehicular activity (EVA) assisted by a mobile platform that moves along the structure to position the astronauts at joint locations where they can latch members in place. Construction can be accomplished from the shuttle cargo bay in the course of a normal flight or from a space station platform. The concepts demonstrates the versatility of machine assisted manned assembly and is only one of many potential applications.

Cucurbit[n]uril-Based Microcapsules Self-Assembled within Microfluidic Droplets: A Versatile Approach for Supramolecular Architectures and Materials

PubMed Central

2017-01-01

Conspectus Microencapsulation is a fundamental concept behind a wide range of daily applications ranging from paints, adhesives, and pesticides to targeted drug delivery, transport of vaccines, and self-healing concretes. The beauty of microfluidics to generate microcapsules arises from the capability of fabricating monodisperse and micrometer-scale droplets, which can lead to microcapsules/particles with fine-tuned control over size, shape, and hierarchical structure, as well as high reproducibility, efficient material usage, and high-throughput manipulation. The introduction of supramolecular chemistry, such as host–guest interactions, endows the resultant microcapsules with stimuli-responsiveness and self-adjusting capabilities, and facilitates hierarchical microstructures with tunable stability and porosity, leading to the maturity of current microencapsulation industry. Supramolecular architectures and materials have attracted immense attention over the past decade, as they open the possibility to obtain a large variety of aesthetically pleasing structures, with myriad applications in biomedicine, energy, sensing, catalysis, and biomimicry, on account of the inherent reversible and adaptive nature of supramolecular interactions. As a subset of supramolecular interactions, host–guest molecular recognition involves the formation of inclusion complexes between two or more moieties, with specific three-dimensional structures and spatial arrangements, in a highly controllable and cooperative manner. Such highly selective, strong yet dynamic interactions could be exploited as an alternative methodology for programmable and controllable engineering of supramolecular architectures and materials, exploiting reversible interactions between complementary components. Through the engineering of molecular structures, assemblies can be readily functionalized based on host–guest interactions, with desirable physicochemical characteristics. In this Account, we summarize the current state of development in the field of monodisperse supramolecular microcapsules, fabricated through the integration of traditional microfluidic techniques and interfacial host–guest chemistry, specifically cucurbit[n]uril (CB[n])-mediated host–guest interactions. Three different strategies, colloidal particle-driven assembly, interfacial condensation-driven assembly and electrostatic interaction-driven assembly, are classified and discussed in detail, presenting the methodology involved in each microcapsule formation process. We highlight the state-of-the-art in design and control over structural complexity with desirable functionality, as well as promising applications, such as cargo delivery stemming from the assembled microcapsules. On account of its dynamic nature, the CB[n]-mediated host–guest complexation has demonstrated efficient response toward various external stimuli such as UV light, pH change, redox chemistry, and competitive guests. Herein, we also demonstrate different microcapsule modalities, which are engineered with CB[n] host–guest chemistry and also can be disrupted with the aid of external stimuli, for triggered release of payloads. In addition to the overview of recent achievements and current limitations of these microcapsules, we finally summarize several perspectives on tunable cargo loading and triggered release, directions, and challenges for this technology, as well as possible strategies for further improvement, which will lead to substainitial progress of host–guest chemistry in supramolecular architectures and materials. PMID:28075551

Current conducting end plate of fuel cell assembly

DOEpatents

Walsh, Michael M.

1999-01-01

A fuel cell assembly has a current conducting end plate with a conductive body formed integrally with isolating material. The conductive body has a first surface, a second surface opposite the first surface, and an electrical connector. The first surface has an exposed portion for conducting current between a working section of the fuel cell assembly and the electrical connector. The isolating material is positioned on at least a portion of the second surface. The conductive body can have support passage(s) extending therethrough for receiving structural member(s) of the fuel cell assembly. Isolating material can electrically isolate the conductive body from the structural member(s). The conductive body can have service passage(s) extending therethrough for servicing one or more fluids for the fuel cell assembly. Isolating material can chemically isolate the one or more fluids from the conductive body. The isolating material can also electrically isolate the conductive body from the one or more fluids.

Feasibility of a 30-meter space based laser transmitter

NASA Technical Reports Server (NTRS)

Berggren, R. R.; Lenertz, G. E.

1975-01-01

A study was made of the application of large expandable mirror structures in future space missions to establish the feasibility and define the potential of high power laser systems for such applications as propulsion and power transmission. Application of these concepts requires a 30-meter diameter, diffraction limited mirror for transmission of the laser energy. Three concepts for the transmitter are presented. These concepts include consideration of continuous as well as segmented mirror surfaces and the major stow-deployment categories of inflatable, variable geometry and assembled-in-space structures. The mirror surface for each concept would be actively monitored and controlled to maintain diffraction limited performance at 10.6 microns during operation. The proposed mirror configurations are based on existing aerospace state-of-the-art technology. The assembled-in-space concept appears to be the most feasible, at this time.

Experiments to evolve toward a tangible user interface for computer-aided design parts assembly

NASA Astrophysics Data System (ADS)

Legardeur, Jeremy; Garreau, Ludovic; Couture, Nadine

2004-05-01

In this paper, we present the concepts of the ESKUA (Experimentation of a Kinesics System Usable for Assembly) platform that allows designers to carry out the assembly of mechanical CAD (Computer Aided Design) parts. This platform, based on tangible user interface lead taking into account assembly constraints from the beginning of the design phase and especially during the phase of CAD models manipulation. Our goal is to propose a working environment where the designer is confronted with real assembly constraints which are currently masked by existing CAD software functionalities. Thus, the platform is based on the handling of physical objects, called tangible interactors, which enable having a physical perception of the assembly constraints. In this goal, we have defined a typology of interactors based on concepts proposed in Design For Assembly methods. We present here the results of studies that led to the evolution of this first interactors set. One is concerning an experiment to evaluate the cognitive aspects of the use of interactors. The other is about an analysis of existing mechanical product and fasteners. We will show how these studies lead to the evolution of the interactors based on the functional surfaces use.

Tetrahedral Arrangements of Perylene Bisimide Columns via Supramolecular Orientational Memory.

PubMed

Sahoo, Dipankar; Peterca, Mihai; Aqad, Emad; Partridge, Benjamin E; Heiney, Paul A; Graf, Robert; Spiess, Hans W; Zeng, Xiangbing; Percec, Virgil

2017-01-24

Chiral, shape, and liquid crystalline memory effects are well-known to produce commercial macroscopic materials with important applications as springs, sensors, displays, and memory devices. A supramolecular orientational memory effect that provides complex nanoscale arrangements was only recently reported. This supramolecular orientational memory was demonstrated to preserve the molecular orientation and packing within supramolecular units of a self-assembling cyclotriveratrylene crown at the nanoscale upon transition between its columnar hexagonal and Pm3̅n cubic periodic arrays. Here we report the discovery of supramolecular orientational memory in a dendronized perylene bisimide (G2-PBI) that self-assembles into tetrameric crowns and subsequently self-organizes into supramolecular columns and spheres. This supramolecular orientation memory upon transition between columnar hexagonal and body-centered cubic (BCC) mesophases preserves the 3-fold cubic [111] orientations rather than the 4-fold [100] axes, generating an unusual tetrahedral arrangement of supramolecular columns. These results indicate that the supramolecular orientational memory concept may be general for periodic arrays of self-assembling dendrons and dendrimers as well as for other periodic and quasiperiodic nanoscale organizations comprising supramolecular spheres, generated from other organized complex soft matter including block copolymers and surfactants.

Role of strongly interacting additives in tuning the structure and properties of polymer systems

NASA Astrophysics Data System (ADS)

Daga, Vikram Kumar

Block copolymer (BCP) nanocomposites are an important class of hybrid materials in which the BCP guides the spatial location and the periodic assembly of the additives. High loadings of well-dispersed nanofillers are generally important for many applications including mechanical reinforcing of polymers. In particular the composites shown in this work might find use as etch masks in nanolithography, or for enabling various phase selective reactions for new materials development. This work explores the use of hydrogen bonding interactions between various additives (such as homopolymers and non-polymeric additives) and small, disordered BCPs to cause the formation of well-ordered morphologies with small domains. A detailed study of the organization of homopolymer chains and the evolution of structure during the process of ordering is performed. The results demonstrate that by tuning the selective interaction of the additive with the incorporating phase of the BCP, composites with significantly high loadings of additives can be formed while maintaining order in the BCP morphology. The possibility of high and selective loading of additives in one of the phases of the ordered BCP composite opens new avenues due to high degree of functionalization and the proximity of the additives within the incorporating phase. This aspect is utilized in one case for the formation of a network structure between adjoining additive cores to derive mesoporous inorganic materials with their structures templated by the BCP. The concept of additive-driven assembly is extended to formulate BCPadditive blends with an ability to undergo photo-induced ordering. Underlying this strategy is the ability to transition a weakly interacting additive to its strongly interacting form. This strategy provides an on-demand, non-intrusive route for formation of well-ordered nanostructures in arbitrarily defined regions of an otherwise disordered material. The second area explored in this dissertation deals with the incorporation of additives into photoresists for next generation extreme ultra violet (EUV) photolithography applications. The concept of hydrogen bonding between the additives and the polymeric photoresist was utilized to cause formation of a physical network that is expected to slow down the diffusion of photoacid leading to better photolithographic performance (25-30 nm resolution obtained).

Challenging Students' Intuitions--The Influence of a Tangible Model of Virus Assembly on Students' Conceptual Reasoning about the Process of Self-Assembly

ERIC Educational Resources Information Center

Larsson, Caroline; Tibell, Lena A.

2015-01-01

A well-ordered biological complex can be formed by the random motion of its components, i.e. self-assemble. This is a concept that incorporates issues that may contradict students' everyday experiences and intuitions. In previous studies, we have shown that a tangible model of virus self-assembly, used in a group exercise, helps students to grasp…

Technological development of multispectral filter assemblies for micro bolometer

NASA Astrophysics Data System (ADS)

Le Goff, Roland; Tanguy, François; Fuss, Philippe; Etcheto, Pierre

2017-11-01

Since 2007 Sodern has successfully developed visible and near infrared multispectral filter assemblies for Earth remote sensing imagers. Filter assembly is manufactured by assembling several sliced filter elements (so-called strips), each corresponding to one spectral band. These strips are cut from wafers using a two dimensional accuracy precision process. In the frame of a 2011 R&T preparatory initiative undertaken by the French agency CNES, the filter assembly concept was adapted by Sodern to the long wave infrared spectral band taken into account the germanium substrate, the multilayer bandpass filters and the F-number of the optics. Indeed the current trend in space instrumentation toward more compact uncooled infrared radiometer leads to replace the filter wheel with a multispectral filter assembly mounted directly above the micro bolometer window. The filter assembly was customized to fit the bolometer size. For this development activity we consider a ULIS VGA LWIR micro bolometer with 640 by 480 pixels and 25 microns pixel pitch. The feasibility of the concept and the ability to withstand space environment were investigated and demonstrated by bread boarding activities. The presentation will contain a detailed description of the bolometer and filter assembly design, the stray light modeling analysis assessing the crosstalk between adjacent spectral bands and the results of the manufacturing and environmental tests (damp heat and thermal vacuum cycling).

Development and Sizing of the JWST Integrated Science Instrument Module (ISIM) Metering Structure

NASA Technical Reports Server (NTRS)

Johnston, John; Kunt, Cengiz; Bartoszyk, Andrew; Hendricks, Steve; Cofie, Emmanuel

2006-01-01

The JWST Integrated Science Instrument Module (ISIM) includes a large metering structure (approx. 2m x 2m x 1.5m) that houses the science instruments and guider. Stringent dimensional stability and repeatability requirements combined with mass limitations led to the selection of a composite bonded frame design comprised of biased laminate tubes. Even with the superb material specific stiffness, achieving the required frequency for the given mass allocations in conjunction with severe spatial limitations imposed by the instrument complement has proven challenging. In response to the challenge, the ISIM structure team considered literally over 100 primary structure topology and kinematic mount configurations, and settled on a concept comprised of over 70 m of tubes, over 50 bonded joint assemblies, and a "split bi-pod" kinematic mount configuration. In this paper, we review the evolution of the ISIM primary structure topology and kinematic mount configuration to the current baseline concept.

Global Cost and Weight Evaluation of Fuselage Side Panel Design Concepts

NASA Technical Reports Server (NTRS)

Polland, D. R.; Finn, S. R.; Griess, K. H.; Hafenrichter, J. L.; Hanson, C. T.; Ilcewicz, L. B.; Metschan, S. L.; Scholz, D. B.; Smith, P. J.

1997-01-01

This report documents preliminary design trades conducted under NASA contracts NAS1 18889 (Advanced Technology Composite Aircraft Structures, ATCAS) and NAS1-19349 (Task 3, Pathfinder Shell Design) for a subsonic wide body commercial aircraft fuselage side panel section utilizing composite materials. Included in this effort were (1) development of two complete design concepts, (2) generation of cost and weight estimates, (3) identification of technical issues and potential design enhancements, and (4) selection of a single design to be further developed. The first design concept featured an open-section stringer stiffened skin configuration while the second was based on honeycomb core sandwich construction. The trade study cost and weight results were generated from comprehensive assessment of each structural component comprising the fuselage side panel section from detail fabrication through airplane final assembly. Results were obtained in three phases: (1) for the baseline designs, (2) after global optimization of the designs, and (3) the results anticipated after detailed design optimization. A critical assessment of both designs was performed to determine the risk associated with each concept, that is the relative probability of achieving the cost and weight projections. Seven critical technical issues were identified as the first step towards side panel detailed design optimization.

Resource Materials for Nanoscale Science and Technology Education

NASA Astrophysics Data System (ADS)

Lisensky, George

2006-12-01

Nanotechnology and advanced materials examples can be used to explore science and engineering concepts, exhibiting the "wow" and potential of nanotechnology, introducing prospective scientists to key ideas, and educating a citizenry capable of making well-informed technology-driven decisions. For example, material syntheses an atomic layer at a time have already revolutionized lighting and display technologies and dramatically expanded hard drive storage capacities. Resource materials include kits, models, and demonstrations that explain scanning probe microscopy, x-ray diffraction, information storage, energy and light, carbon nanotubes, and solid-state structures. An online Video Lab Manual, where movies show each step of the experiment, illustrates more than a dozen laboratory experiments involving nanoscale science and technology. Examples that are useful at a variety of levels when instructors provide the context include preparation of self-assembled monolayers, liquid crystals, colloidal gold, ferrofluid nanoparticles, nickel nanowires, solar cells, electrochromic thin films, organic light emitting diodes, and quantum dots. These resources have been developed, refined and class tested at institutions working with the Materials Research Science and Engineering Center on Nanostructured Interfaces at the University of Wisconsin-Madison (http://mrsec.wisc.edu/nano).

Method for recovering catalytic elements from fuel cell membrane electrode assemblies

DOEpatents

Shore, Lawrence [Edison, NJ; Matlin, Ramail [Berkeley Heights, NJ; Heinz, Robert [Ludwigshafen, DE

2012-06-26

A method for recovering catalytic elements from a fuel cell membrane electrode assembly is provided. The method includes converting the membrane electrode assembly into a particulate material, wetting the particulate material, forming a slurry comprising the wetted particulate material and an acid leachate adapted to dissolve at least one of the catalytic elements into a soluble catalytic element salt, separating the slurry into a depleted particulate material and a supernatant containing the catalytic element salt, and washing the depleted particulate material to remove any catalytic element salt retained within pores in the depleted particulate material.

Layer-by-layer assembly of nanostructured composites: Mechanics and applications

NASA Astrophysics Data System (ADS)

Podsiadlo, Paul

The development of efficient methods for preparation of nanometer-sized materials and our evolving ability to manipulate the nanoscale objects have brought about a scientific and technological revolution called: nanotechnology. This revolution has been especially driven by discovery of unique nanoscale properties of the nanomaterials which are governed by their inherent size. Today, the total societal impact of nanotechnology is expected to be greater than the combined influences that the silicon integrated circuit, medical imaging, computer-aided engineering, and man-made polymers have had in the last century. Many nanomaterials were also found to possess exceptional mechanical properties. This led to tremendous interest into developing composite materials by exploiting the mechanical properties of these building blocks. In spite of a tremendous volume of work done in the field, preparation of such nanocomposites (NCs) has proven to be elusive due to inability of traditional "top-down" fabrication approaches to effectively harness properties of the nano-scale building blocks. This thesis focuses on preparation of organic/inorganic and solely organic NCs via a bottom-up nano-manufacturing approach called the layer-by-layer (LBL) assembly. Two natural and inexpensive nanoscale building blocks are explored: nanosheets of Na+-montmorillonite clay (MTM) and rod-shaped nanocrystals of cellulose (CNRs). In the first part of the thesis, we present results from systematic study of mechanics of MTM-based NCs. Different compositions are explored with a goal of understanding the nanoscale mechanics. Ultimately, development of a transparent composite with record-high strength and stiffness is presented. In the second part, we present results from LBL assembly of the CNRs. We demonstrate feasibility of assembly and mechanical properties of the resulting films. We also demonstrate preparation of LBL films with anti- reflective properties from tunicate (a sea animal) CNRs. In the final part, we show preparation of high toughness and hierarchically organized NCs using two concepts: "exponential" LBL (e-LBL) assembly and charged polyurethanes. We show preparation of novel e-LBL structures and highly flexible LBL multilayers. We also demonstrate preparation of macro-scale composites from hierarchical, post-assembly consolidation of LBL sheets. This last result represents a potential paradigm change in the practice of LBL assembly by enabling transformation of the thin-films into macro-scale structures.

Space station operations management

NASA Technical Reports Server (NTRS)

Cannon, Kathleen V.

1989-01-01

Space Station Freedom operations management concepts must be responsive to the unique challenges presented by the permanently manned international laboratory. Space Station Freedom will be assembled over a three year period where the operational environment will change as significant capability plateaus are reached. First Element Launch, Man-Tended Capability, and Permanent Manned Capability, represent milestones in operational capability that is increasing toward mature operations capability. Operations management concepts are being developed to accomodate the varying operational capabilities during assembly, as well as the mature operational environment. This paper describes operations management concepts designed to accomodate the uniqueness of Space Station Freedoom, utilizing tools and processes that seek to control operations costs.

Lightweight deformable mirrors for future space telescopes

NASA Astrophysics Data System (ADS)

Patterson, Keith

This thesis presents a concept for ultra-lightweight deformable mirrors based on a thin substrate of optical surface quality coated with continuous active piezopolymer layers that provide modes of actuation and shape correction. This concept eliminates any kind of stiff backing structure for the mirror surface and exploits micro-fabrication technologies to provide a tight integration of the active materials into the mirror structure, to avoid actuator print-through effects. Proof-of-concept, 10-cm-diameter mirrors with a low areal density of about 0.5 kg/m2 have been designed, built and tested to measure their shape-correction performance and verify the models used for design. The low cost manufacturing scheme uses replication techniques, and strives for minimizing residual stresses that deviate the optical figure from the master mandrel. It does not require precision tolerancing, is lightweight, and is therefore potentially scalable to larger diameters for use in large, modular space telescopes. Other potential applications for such a laminate could include ground-based mirrors for solar energy collection, adaptive optics for atmospheric turbulence, laser communications, and other shape control applications. The immediate application for these mirrors is for the Autonomous Assembly and Reconfiguration of a Space Telescope (AAReST) mission, which is a university mission under development by Caltech, the University of Surrey, and JPL. The design concept, fabrication methodology, material behaviors and measurements, mirror modeling, mounting and control electronics design, shape control experiments, predictive performance analysis, and remaining challenges are presented herein. The experiments have validated numerical models of the mirror, and the mirror models have been used within a model of the telescope in order to predict the optical performance. A demonstration of this mirror concept, along with other new telescope technologies, is planned to take place during the AAReST mission.

Robotically Assembled Aerospace Structures: Digital Material Assembly using a Gantry-Type Assembler

NASA Technical Reports Server (NTRS)

Trinh, Greenfield; Copplestone, Grace; O'Connor, Molly; Hu, Steven; Nowak, Sebastian; Cheung, Kenneth; Jenett, Benjamin; Cellucci, Daniel

2017-01-01

This paper evaluates the development of automated assembly techniques for discrete lattice structures using a multi-axis gantry type CNC machine. These lattices are made of discrete components called digital materials. We present the development of a specialized end effector that works in conjunction with the CNC machine to assemble these lattices. With this configuration we are able to place voxels at a rate of 1.5 per minute. The scalability of digital material structures due to the incremental modular assembly is one of its key traits and an important metric of interest. We investigate the build times of a 5x5 beam structure on the scale of 1 meter (325 parts), 10 meters (3,250 parts), and 30 meters (9,750 parts). Utilizing the current configuration with a single end effector, performing serial assembly with a globally fixed feed station at the edge of the build volume, the build time increases according to a scaling law of n4, where n is the build scale. Build times can be reduced significantly by integrating feed systems into the gantry itself, resulting in a scaling law of n3. A completely serial assembly process will encounter time limitations as build scale increases. Automated assembly for digital materials can assemble high performance structures from discrete parts, and techniques such as built in feed systems, parallelization, and optimization of the fastening process will yield much higher throughput.

Robotically Assembled Aerospace Structures: Digital Material Assembly using a Gantry-Type Assembler

NASA Technical Reports Server (NTRS)

Trinh, Greenfield; Copplestone, Grace; O'Connor, Molly; Hu, Steven; Nowak, Sebastian; Cheung, Kenneth; Jenett, Benjamin; Cellucci, Daniel

2017-01-01

This paper evaluates the development of automated assembly techniques for discrete lattice structures using a multi-axis gantry type CNC machine. These lattices are made of discrete components called "digital materials." We present the development of a specialized end effector that works in conjunction with the CNC machine to assemble these lattices. With this configuration we are able to place voxels at a rate of 1.5 per minute. The scalability of digital material structures due to the incremental modular assembly is one of its key traits and an important metric of interest. We investigate the build times of a 5x5 beam structure on the scale of 1 meter (325 parts), 10 meters (3,250 parts), and 30 meters (9,750 parts). Utilizing the current configuration with a single end effector, performing serial assembly with a globally fixed feed station at the edge of the build volume, the build time increases according to a scaling law of n4, where n is the build scale. Build times can be reduced significantly by integrating feed systems into the gantry itself, resulting in a scaling law of n3. A completely serial assembly process will encounter time limitations as build scale increases. Automated assembly for digital materials can assemble high performance structures from discrete parts, and techniques such as built in feed systems, parallelization, and optimization of the fastening process will yield much higher throughput.

Optoelectronic functional materials based on alkylated-π molecules: self-assembled architectures and nonassembled liquids.

PubMed

Li, Hongguang; Choi, Jiyoung; Nakanishi, Takashi

2013-05-07

The engineering of single molecules into higher-order hierarchical assemblies is a current research focus in molecular materials chemistry. Molecules containing π-conjugated units are an important class of building blocks because their self-assembly is not only of fundamental interest, but also the key to fabricating functional systems for organic electronic and photovoltaic applications. Functionalizing the π-cores with "alkyl chains" is a common strategy in the molecular design that can give the system desirable properties, such as good solubility in organic solvents for solution processing. Moreover, the alkylated-π system can regulate the self-assembly behavior by fine-tuning the intermolecular forces. The optimally assembled structures can then exhibit advanced functions. However, while some general rules have been revealed, a comprehensive understanding of the function played by the attached alkyl chains is still lacking, and current methodology is system-specific in many cases. Better clarification of this issue requires contributions from carefully designed libraries of alkylated-π molecular systems in both self-assembly and nonassembly materialization strategies. Here, based on recent efforts toward this goal, we show the power of the alkyl chains in controlling the self-assembly of soft molecular materials and their resulting optoelectronic properties. The design of alkylated-C60 is selected from our recent research achievements, as the most attractive example of such alkylated-π systems. Some other closely related systems composed of alkyl chains and π-units are also reviewed to indicate the universality of the methodology. Finally, as a contrast to the self-assembled molecular materials, nonassembled, solvent-free, novel functional liquid materials are discussed. In doing so, a new journey toward the ultimate organic "soft" materials is introduced, based on alkylated-π molecular design.

Layer-by-Layer Assembly of a pH-Responsive and Electrochromic Thin Film

ERIC Educational Resources Information Center

Schmidt, Daniel J.; Pridgen, Eric M.; Hammond, Paula T.; Love, J. Christopher

2010-01-01

This article summarizes an experiment on thin-film fabrication with layer-by-layer assembly that is appropriate for undergraduate laboratory courses. The purpose of this experiment is to teach students about self-assembly in the context of thin films and to expose students to the concepts of functional polymeric coatings. Students dip coat…

Lunar surface construction and assembly equipment study: Lunar Base Systems Study (LBSS) task 5.3

NASA Technical Reports Server (NTRS)

1988-01-01

A set of construction and assembly tasks required on the lunar surface was developed, different concepts for equipment applicable to the tasks determined, and leading candidate systems identified for future conceptual design. Data on surface construction and assembly equipment systems are necessary to facilitate an integrated review of a complete lunar scenario.

49 CFR 178.358-6 - Typical assembly detail.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Typical assembly detail. 178.358-6 Section 178.358-6 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS... PACKAGINGS Specifications for Packagings for Class 7 (Radioactive) Materials § 178.358-6 Typical assembly...

49 CFR 178.356-5 - Typical assembly detail.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Typical assembly detail. 178.356-5 Section 178.356-5 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS... PACKAGINGS Specifications for Packagings for Class 7 (Radioactive) Materials § 178.356-5 Typical assembly...

Self-assembly of nucleic acids, silk and hybrid materials thereof.

PubMed

Humenik, Martin; Scheibel, Thomas

2014-12-17

Top-down approaches based on etching techniques have almost reached their limits in terms of dimension. Therefore, novel assembly strategies and types of nanomaterials are required to allow technological advances. Self-assembly processes independent of external energy sources and unlimited in dimensional scaling have become a very promising approach. Here,we highlight recent developments in self-assembled DNA-polymer, silk-polymer and silk-DNA hybrids as promising materials with biotic and abiotic moieties for constructing complex hierarchical materials in ‘bottom-up’ approaches. DNA block copolymers assemble into nanostructures typically exposing a DNA corona which allows functionalization, labeling and higher levels of organization due to its specific addressable recognition properties. In contrast, self-assembly of natural silk proteins as well as their recombinant variants yields mechanically stable β-sheet rich nanostructures. The combination of silk with abiotic polymers gains hybrid materials with new functionalities. Together, the precision of DNA hybridization and robustness of silk fibrillar structures combine in novel conjugates enable processing of higher-order structures with nanoscale architecture and programmable functions.

Self-assembly of nucleic acids, silk and hybrid materials thereof

NASA Astrophysics Data System (ADS)

Humenik, Martin; Scheibel, Thomas

2014-12-01

Top-down approaches based on etching techniques have almost reached their limits in terms of dimension. Therefore, novel assembly strategies and types of nanomaterials are required to allow technological advances. Self-assembly processes independent of external energy sources and unlimited in dimensional scaling have become a very promising approach. Here, we highlight recent developments in self-assembled DNA-polymer, silk-polymer and silk-DNA hybrids as promising materials with biotic and abiotic moieties for constructing complex hierarchical materials in ‘bottom-up’ approaches. DNA block copolymers assemble into nanostructures typically exposing a DNA corona which allows functionalization, labeling and higher levels of organization due to its specific addressable recognition properties. In contrast, self-assembly of natural silk proteins as well as their recombinant variants yields mechanically stable β-sheet rich nanostructures. The combination of silk with abiotic polymers gains hybrid materials with new functionalities. Together, the precision of DNA hybridization and robustness of silk fibrillar structures combine in novel conjugates enable processing of higher-order structures with nanoscale architecture and programmable functions.

Detail design of the surface tension propellant management device for the Intelsat VII communication satellite

NASA Astrophysics Data System (ADS)

Giacalone, Philip L.

1993-06-01

The design of the Intelsat VII surface tension propellant management device (PMD) (an all-welded assembly consisting of about 100 individual components) was developed using a modular design approach that allowed the complex PMD assembly to be divided into smaller modules. The modular approach reduces manufacturing-related technical and schedule risks and allows many components and assemblies to be processed in parallel, while also facilitating the incorporation of quality assurance tests at all critical PMD subassembly levels. The baseline PMD assembly is made from titanium and stainless steel materials. In order to obtain a 100 percent titanium PMD, a new, state-of-the-art fine mesh titanium screen material was developed, tested, and qualified for use as an alternaltive to the stainless steel screen material. The Ti based screen material demonstrated a high level of bubble point performance. It was integrated into a PMD assembly and was successfully qualification tested at the tank assembly level.

Apparatus and method for measuring the Seebeck coefficient and resistivity of materials

NASA Technical Reports Server (NTRS)

Hadek, V. (Inventor)

1973-01-01

An apparatus for measuring the thermoelectric properties of materials under high pressure is described that includes a pair of force transmitting assemblies constructed of thermally and electrically conductive material positioned between the ram and anvil of a press. Each force transmitting assembly has a small diameter pressing portion for contacting a face of the sample so that the sample can be squeezed between them. Each assembly also includes a heat exchanger to maintain the sample face at a controlled temperature, and an electrical conductor to carry current generated by the sample. A sleeve of thermally and electrically insulative material closely surrounds the pressing portions of the two assemblies.

Repair Concepts as Design Constraints of a Stiffened Composite PRSEUS Panel

NASA Technical Reports Server (NTRS)

Przekop, Adam

2012-01-01

A design and analysis of a repair concept applicable to a stiffened thin-skin composite panel based on the Pultruded Rod Stitched Efficient Unitized Structure is presented. The concept is a bolted repair using metal components, so that it can easily be applied in the operational environment. The damage scenario considered is a midbay-to-midbay saw-cut with a severed stiffener, flange and skin. In a previous study several repair configurations were explored and their feasibility confirmed but refinement was needed. The present study revisits the problem under recently revised design requirements and broadens the suite of loading conditions considered. The repair assembly design is based on the critical tension loading condition and subsequently its robustness is verified for a pressure loading case. High fidelity modeling techniques such as mesh-independent definition of compliant fasteners, elastic-plastic material properties for metal parts and geometrically nonlinear solutions are utilized in the finite element analysis. The best repair design is introduced, its analysis results are presented and factors influencing the design are assessed and discussed.

An analytical investigation of a conceptual design for the station transverse boom rotary joint structure

NASA Technical Reports Server (NTRS)

Lake, M. S.; Bush, H. G.

1986-01-01

A study was conducted to define an annular ring, discrete roller assembly concept for the space station transverse boom rotary joint. The concept was analyzed using closed-form and finite element techniques, to size structural members for a range of joint diameters and to determine necessary equivalent stiffnesses for the roller assemblies. Also, a mass study of the system was conducted to determine its practicality, and maximum loads in the joint were identified. To obtain the optimum balance between high stiffness and low structural mass in the design of the rotary joint, it is necessary to maximize the diameter of the annular ring within operational constraints (i.e., shuttle cargo bay size). Further, a rotary joint designed with the largest possible ring diameter will result in minimum operational loads in both the roller assemblies and the transition truss members while also allowing minimum design stiffnesses for the roller assemblies.

Recent Advances in Multi-component Particles Assembly.

PubMed

Guo, Dan; Song, Yanlin

2018-03-09

Particles assembly and co-assembly have been research frontiers in chemistry and material science in the past few decades. To achieve a large variety of intricate structures and functional materials, remarkable progress has been made in the particle assembly principles and strategies. It can be summarized that the particle assembly is driven by intrinsic interparticle interaction or the external control. In this article, we focus on binary or ternary particles co-assembly and review the principles and feasible strategies. These advances have led to new disciplines of microfabrication technology and material engineering. Although remarked achievement on particle-based structures has been made, it is still challenging to fully develop general and facile strategies to precisely control the one-dimensional (1D) co-assembly. This article reviews the recent development on multi-component particles co-assembly, which significantly increases structural complexity and functional diversity. In particular, we highlight the advances in the particles co-assembly of well-ordered 1D binary superstructures by liquid soft confinement. Finally, prospective outlook for future trends in this field is proposed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Space structures concepts and materials

NASA Technical Reports Server (NTRS)

Nowitzky, A. M.; Supan, E. C.

1988-01-01

An extension is preseted of the evaluation of graphite/aluminum metal matrix composites (MMC) for space structures application. A tubular DWG graphite/aluminum truss assembly was fabricated having the structural integrity and thermal stability needed for space application. DWG is a proprietary thin ply continuous graphite reinforced aluminum composite. The truss end fittings were constructed using the discontinuous ceramic particulate reinforced MMC DWAl 20 (trademark). Thermal stability was incorporated in the truss by utilizing high stiffness, negative coefficient of thermal expansion (CTE) P100 graphite fibers in a 6061 aluminum matrix, crossplied to provide minimized CTE in the assembled truss. Tube CTE was designed to be slightly negative to offset the effects of the end fitting and sleeve, CTE values of which are approx. 1/2 that of aluminum. In the design of the truss configuration, the CTE contribution of each component was evaluated to establish the component dimension and layup configuration required to provide a net zero CTE in the subassemblies which would then translate to a zero CTE for the entire truss bay produced.

Supramolecular core-shell nanoparticles for photoconductive device applications

NASA Astrophysics Data System (ADS)

Cheng, Chih-Chia; Chen, Jem-Kun; Shieh, Yeong-Tarng; Lee, Duu-Jong

2016-08-01

We report a breakthrough discovery involving supramolecular-based strategies to construct novel core-shell heterojunction nanoparticles with hydrophilic adenine-functionalized polythiophene (PAT) as the core and hydrophobic phenyl-C61-butyric acid methyl ester (PCBM) as the shell, which enables the conception of new functional supramolecular assemblies for constructing functional nanomaterials for applications in optoelectronic devices. The generated nanoparticles exhibit uniform spherical shape, well-controlled tuning of particle size with narrow size distributions, and excellent electrochemical stability in solution and the solid state owing to highly efficient energy transfer from PAT to PCBM. When the PAT/PCBM nanoparticles were fabricated into a photoconducting layer in an electronic device, the resulting device showed excellent electric conduction characteristics, including an electrically-tunable voltage-controlled switch, and high short-circuit current and open-circuit voltage. These observations demonstrate how the self-assembly of PAT/PCBM into specific nanostructures may help to promote efficient charge generation and transport processes, suggesting potential for a wide variety of applications as a promising candidate material for bulk heterojunction polymer devices.

High-performance vertical organic transistors.

PubMed

Kleemann, Hans; Günther, Alrun A; Leo, Karl; Lüssem, Björn

2013-11-11

Vertical organic thin-film transistors (VOTFTs) are promising devices to overcome the transconductance and cut-off frequency restrictions of horizontal organic thin-film transistors. The basic physical mechanisms of VOTFT operation, however, are not well understood and VOTFTs often require complex patterning techniques using self-assembly processes which impedes a future large-area production. In this contribution, high-performance vertical organic transistors comprising pentacene for p-type operation and C60 for n-type operation are presented. The static current-voltage behavior as well as the fundamental scaling laws of such transistors are studied, disclosing a remarkable transistor operation with a behavior limited by injection of charge carriers. The transistors are manufactured by photolithography, in contrast to other VOTFT concepts using self-assembled source electrodes. Fluorinated photoresist and solvent compounds allow for photolithographical patterning directly and strongly onto the organic materials, simplifying the fabrication protocol and making VOTFTs a prospective candidate for future high-performance applications of organic transistors. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thermal expansion method for lining tantalum alloy tubing with tungsten

NASA Technical Reports Server (NTRS)

Watson, G. K.; Whittenberger, J. D.; Mattson, W. F.

1973-01-01

A differential-thermal expansion method was developed to line T-111 (tantalum - 8 percent tungsten - 2 percent hafnium) tubing with a tungsten diffusion barrier as part of a fuel element fabrication study for a space power nuclear reactor concept. This method uses a steel mandrel, which has a larger thermal expansion than T-111, to force the tungsten against the inside of the T-111 tube. Variables investigated include lining temperature, initial assembly gas size, and tube length. Linear integrity increased with increasing lining temperature and decreasing gap size. The method should have more general applicability where cylinders must be lined with a thin layer of a second material.

Development of a Woven-Grid Quasi-Bipolar Battery

NASA Technical Reports Server (NTRS)

Tokumaru, P.; Rippel, W.; Zambrano, T.

1998-01-01

This report describes an analytical and experimental investigation of AeroVironment's Quasi-Bipolar battery concept. The modelling/battery design part of the study demonstrates that there is a trade-off between thermal and specified electrical performance. Even so, quasi-bipolar batteries can be designed, with ten times better thermal uniformity, that meet or exceed current state-of-the-art hybrid-electric vehicle battery pack performance, even using the same active materials. The thermal uniformity, power, and energy for these quasi-bipolar battery packs is projected to be very good. The experimental part of the investigation demonstrates the concept of the quasi-bipolar plate applied to a lead foil current collector wrapping around two sides of an inexpensive plastic film core. Approximately 50 quasi-biplate samples were fabricated using a hot laminating press. Hot lamination with "texture" between the plastic and lead shows some promise as a low cost method for fabricating the plates. Five of these plates were assembled into two cells plus one two-cell battery. Data from these test cells were compared with existing data for similar true bipolar batteries. The positive side of the plates exhibited corrosion where not protected by the active material.

Multifunctional shape-memory polymers.

PubMed

Behl, Marc; Razzaq, Muhammad Yasar; Lendlein, Andreas

2010-08-17

The thermally-induced shape-memory effect (SME) is the capability of a material to change its shape in a predefined way in response to heat. In shape-memory polymers (SMP) this shape change is the entropy-driven recovery of a mechanical deformation, which was obtained before by application of external stress and was temporarily fixed by formation of physical crosslinks. The high technological significance of SMP becomes apparent in many established products (e.g., packaging materials, assembling devices, textiles, and membranes) and the broad SMP development activities in the field of biomedical as well as aerospace applications (e.g., medical devices or morphing structures for aerospace vehicles). Inspired by the complex and diverse requirements of these applications fundamental research is aiming at multifunctional SMP, in which SME is combined with additional functions and is proceeding rapidly. In this review different concepts for the creation of multifunctionality are derived from the various polymer network architectures of thermally-induced SMP. Multimaterial systems, such as nanocomposites, are described as well as one-component polymer systems, in which independent functions are integrated. Future challenges will be to transfer the concept of multifunctionality to other emerging shape-memory technologies like light-sensitive SMP, reversible shape changing effects or triple-shape polymers.

Conceptual design of modular fixture for frame welding and drilling process integration case study: Student chair in UNS industrial engineering integrated practicum

NASA Astrophysics Data System (ADS)

Darmawan, Tofiq Dwiki; Priadythama, Ilham; Herdiman, Lobes

2018-02-01

Welding and drilling are main processes of making chair frame from metal material. Commonly, chair frame construction includes many arcs which bring difficulties for its welding and drilling process. In UNS industrial engineering integrated practicum there are welding fixtures which use to fixing frame component position for welding purpose. In order to achieve exact holes position for assembling purpose, manual drilling processes were conducted after the frame was joined. Unfortunately, after it was welded the frame material become hard and increase drilling tools wear rate as well as reduce holes position accuracy. The previous welding fixture was not equipped with clamping system and cannot accommodate drilling process. To solve this problem, our idea is to reorder the drilling process so that it can be execute before welding. Thus, this research aims to propose conceptual design of modular fixture which can integrate welding and drilling process. We used Generic Product Development Process to address the design concept. We collected design requirements from 3 source, jig and fixture theoretical concepts, user requirements, and clamping part standards. From 2 alternatives fixture tables, we propose the first which equipped with mounting slots instead of holes. We test the concept by building a full sized prototype and test its works by conducting welding and drilling of a student chair frame. Result from the welding and drilling trials showed that the holes are on precise position after welding. Based on this result, we conclude that the concept can be a consideration for application in UNS Industrial Engineering Integrated Practicum.

Geometric correction methods for Timepix based large area detectors

NASA Astrophysics Data System (ADS)

Zemlicka, J.; Dudak, J.; Karch, J.; Krejci, F.

2017-01-01

X-ray micro radiography with the hybrid pixel detectors provides versatile tool for the object inspection in various fields of science. It has proven itself especially suitable for the samples with low intrinsic attenuation contrast (e.g. soft tissue in biology, plastics in material sciences, thin paint layers in cultural heritage, etc.). The limited size of single Medipix type detector (1.96 cm2) was recently overcome by the construction of large area detectors WidePIX assembled of Timepix chips equipped with edgeless silicon sensors. The largest already built device consists of 100 chips and provides fully sensitive area of 14.3 × 14.3 cm2 without any physical gaps between sensors. The pixel resolution of this device is 2560 × 2560 pixels (6.5 Mpix). The unique modular detector layout requires special processing of acquired data to avoid occurring image distortions. It is necessary to use several geometric compensations after standard corrections methods typical for this type of pixel detectors (i.e. flat-field, beam hardening correction). The proposed geometric compensations cover both concept features and particular detector assembly misalignment of individual chip rows of large area detectors based on Timepix assemblies. The former deals with larger border pixels in individual edgeless sensors and their behaviour while the latter grapple with shifts, tilts and steps between detector rows. The real position of all pixels is defined in Cartesian coordinate system and together with non-binary reliability mask it is used for the final image interpolation. The results of geometric corrections for test wire phantoms and paleo botanic material are presented in this article.

Fabrication of capsule assemblies, phase 3

NASA Technical Reports Server (NTRS)

Keeton, A. R.; Stemann, L. G.

1973-01-01

Thirteen capsule assemblies were fabricated for evaluation of fuel pin design concepts for a fast spectrum lithium cooled compact space power reactor. These instrumented assemblies were designed for real time test of prototype fuel pins. Uranium mononitride fuel pins were encased in AISI 304L stainless steel capsules. Fabrication procedures were fully qualified by process development and assembly qualification tests. Instrumentation reliability was achieved utilizing specially processed and closely controlled thermocouple hot zone fabrication and by thermal screening tests. Overall capsule reliability was achieved with an all electron beam welded assembly.

A definition study of the on-orbit assembly operations for the outboard photovoltaic power modules for Space Station Freedom. M.S. Thesis - Toledo Univ.

NASA Technical Reports Server (NTRS)

Sours, Thomas J.

1989-01-01

A concept is described for the assembly of the outboard PV modules for Space Station Freedom. Analysis of the on-orbit assembly operations was performed using CADAM design graphics software. A scenario for assembly using the various assembly equipment, as currently defined, is described in words, tables and illustrations. This work is part of ongoing studies in the area of space station assembly. The outboard PV module and the assembly equipment programs are all in definition and preliminary design phases. An input is provided to the design process of assembly equipment programs. It is established that the outboard PV module assembly operations can be performed using the assembly equipment currently planned in the Space Station Freedom Program.

Emerging Insights into Directed Assembly: Taking Examples from Nature to Design Synthetic Processes

NASA Astrophysics Data System (ADS)

de Pablo, Juan J.

There is considerable interest in controlling the assembly of polymeric material in order to create highly ordered materials for applications. Such materials are often trapped in metastable, non-equilibrium states, and the processes through which they assemble become an important aspect of the materials design strategy. An example is provided by di-block copolymer directed self-assembly, where a decade of work has shown that, through careful choice of process variables, it is possible to create ordered structures whose degree of perfection meets the constraints of commercial semiconductor manufacturing. As impactful as that work has been, it has focused on relatively simple materials neutral polymers, consisting of two or at most three blocks. Furthermore, the samples that have been produced have been limited to relatively thin films, and the assembly has been carried out on ideal, two-dimensional substrates. The question that arises now is whether one can translate those achievements to polymeric materials having a richer sequence, to monomers that include charges, to three-dimensional substrates, or to active systems that are in a permanent non-equilibrium state. Building on discoveries from the biophysics literature, this presentation will review recent work from our group and others that explains how nature has evolved to direct the assembly of nucleic acids into intricate, fully three-dimensional macroscopic functional materials that are not only active, but also responsive to external cues. We will discuss how principles from polymer physics serve to explain those assemblies, and how one might design a new generation of synthetic systems that incorporate some of those principles.

Recovering tubewise power from three-dimensional nodal kinetics calculation during material relocation in an HWR

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

Kalimullah; Morris, E.E.; Yang, W.S.

1994-12-31

To analyze severe accidents in some special-purpose heavy-water reactors made of assemblies consisting of a number of coaxial tubes of aluminum-clad U-Al fuel and aluminum-clad neutron-capturing material, a mechanistic model, MARTINS, for tube beatup, melting, and molten material relocation has been developed and integrated with the DIF3D nodal hexagonal-z reactor kinetics and other phenomenological modules. The DIF3D kinetics homogenizes all materials located and computes the total power produced in an axial segment of a fuel assembly. This paper presents an approximate method, used in MARTINS, to calculate the distribution of this total nodal power into the intact fuel and capturingmore » material tubes and the meat-cladding mixtures relocating during tube disruption. The method accounts for the change in intraassembly radial power profile due to assembly geometry change with the progress of segment-by-segment disruption of different tubes. Earlier methods to recover pinwise power from nodal calculation for liquid-metal-cooled reactors and light water reactors (X-Y and hexagonal unit cells) are not practical for a disrupting assembly having material relocation. Figure 1 shows the assembly`s end view, divided into rings for modeling and analysis. A ring is a coolant subchannel plus the outer surrounding tube. The present method for distributing the nodal power consists of two parts: (a) calculation of the relative values of ring-by-ring power per unit uranium mass and power per unit mass of neutron-capturing material in a given assembly segment, and (b) normalization of these relative values such that the total power of all rings (intact tubes and U-Al-Cp meat-cladding mixtures, where Cp implies the neutron-capturing material) equals the DIF3D-calculated nodal power for the assembly axial segment.« less

Manufacturing development for the SAFE 100 kW core

NASA Astrophysics Data System (ADS)

Carter, Robert; Roman, Jose; Salvail, Pat

2002-01-01

In stark contrast to what is sometimes considered the norm in traditional manufacturing processes, engineers at the Marshall Space Flight Center (MSFC) arc in the practice of altering the standard in an effort to realize other potential methods in core manufacturing. While remaining within the bounds of the materials database, we are researching into core manufacturing techniques that may have been overlooked in the past due to funding and/or time constraints. To augment proven core fabrication capabilities we are pursuing plating processes as another possible method for core build-up and assembly. Although brazing and a proprietary HIP cycle are used for module assembly (proven track record for stability and endurance), it is prudent to pursue secondary or backup methods of module and core assembly. For this reason heat tube manufacture and module assembly by means of plating is being investigated. Potentially, the plating processes will give engineers the ability to manufacture replacement modules for any module that might fail to perform nominally, and to assemble/disassemble a complete core in much less time than would be required for the conventional Braze-HIP process. Another area of improvement in core manufacturing capabilities is the installation of a sodium and lithium liquid metal heat pipe fill machine. This, along with the ability to Electron Beam Weld heat pipe seals and wet-in the pipes in the necessary vacuum atmosphere, will eliminate the need to ship potentially hazardous components outside for processing. In addition to developing core manufacturing techniques, the SAFE manufacturing team has been evaluating the thermal heat transfer characteristics, and manufacturability of several heat exchanger design concepts. .

Natural supramolecular building blocks: from virus coat proteins to viral nanoparticles.

PubMed

Liu, Zhi; Qiao, Jing; Niu, Zhongwei; Wang, Qian

2012-09-21

Viruses belong to a fascinating class of natural supramolecular structures, composed of multiple copies of coat proteins (CPs) that assemble into different shapes with a variety of sizes from tens to hundreds of nanometres. Because of their advantages including simple/economic production, well-defined structural features, unique shapes and sizes, genetic programmability and robust chemistries, recently viruses and virus-like nanoparticles (VLPs) have been used widely in biomedical applications and materials synthesis. In this critical review, we highlight recent advances in the use of virus coat proteins (VCPs) and viral nanoparticles (VNPs) as building blocks in self-assembly studies and materials development. We first discuss the self-assembly of VCPs into VLPs, which can efficiently incorporate a variety of different materials as cores inside the viral protein shells. Then, the self-assembly of VNPs at surfaces or interfaces is summarized. Finally, we discuss the co-assembly of VNPs with different functional materials (178 references).

A synopsis of the EVA training conducted on EASE/ACCESS for STS-61-B

NASA Technical Reports Server (NTRS)

Havens, Kathryn A.

1987-01-01

Experimental Assembly of Structure in EVA (EASE)/Assembly Concept for Construction of Erectable Space Structures (ACCESS) training problems; photography/television coverage; training schedules; flight data file (FDF), and flight rules production are summarized.

Massively Parallel Nanostructure Assembly Strategies for Sensing and Information Technology. Phase 2

DTIC Science & Technology

2013-05-25

field. This work has focused on the synthesis of new functional materials and the development of high-throughput, facile methods to assemble...Hong (Seoul National University, Korea). Specifically, gapped nanowires (GNW) were identified as candidate materials for synthesis and assembly as...Throughout the course of this grant, we reported major accomplishments both in the synthesis and assembly of such structures. Synthetically, we report three

Innovation in Layer-by-Layer Assembly.

PubMed

Richardson, Joseph J; Cui, Jiwei; Björnmalm, Mattias; Braunger, Julia A; Ejima, Hirotaka; Caruso, Frank

2016-12-14

Methods for depositing thin films are important in generating functional materials for diverse applications in a wide variety of fields. Over the last half-century, the layer-by-layer assembly of nanoscale films has received intense and growing interest. This has been fueled by innovation in the available materials and assembly technologies, as well as the film-characterization techniques. In this Review, we explore, discuss, and detail innovation in layer-by-layer assembly in terms of past and present developments, and we highlight how these might guide future advances. A particular focus is on conventional and early developments that have only recently regained interest in the layer-by-layer assembly field. We then review unconventional assemblies and approaches that have been gaining popularity, which include inorganic/organic hybrid materials, cells and tissues, and the use of stereocomplexation, patterning, and dip-pen lithography, to name a few. A relatively recent development is the use of layer-by-layer assembly materials and techniques to assemble films in a single continuous step. We name this "quasi"-layer-by-layer assembly and discuss the impacts and innovations surrounding this approach. Finally, the application of characterization methods to monitor and evaluate layer-by-layer assembly is discussed, as innovation in this area is often overlooked but is essential for development of the field. While we intend for this Review to be easily accessible and act as a guide to researchers new to layer-by-layer assembly, we also believe it will provide insight to current researchers in the field and help guide future developments and innovation.

Tokamak blanket design study, final report

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

Not Available

1980-08-01

A cylindrical module concept was developed, analyzed, and incorporated in a tokamak blanket system that includes piping systems, vacuum boundary sealing, and support structures. The design is based on the use of state-of-the-art structural materials (20% cold-worked type 316 stainless steel), lithium as the breeding material, and pressurized helium as the coolant. The module design consists of nested concentric cylinders (with an outer diameter of 10 cm) and features direct wall cooling by helium flowing between the outer (first-wall) cylinder and the inner (lithium-containing) cylinder. Each cylinder can withstand full coolant pressure, thus enhancing reliability. Results show that stainless steelmore » is a viable material for a first wall subjected to a neutron wall loading of 4 MW/m/sup 2/ and a particle heat flux of 1 MW/m/sup 2/. Lifetime analysis shows that the first-wall design meets the goal of operating at 20-min cycles with 95% duty for 100,000 cycles. To reduce system complexity, a larger 20-cm-diam module also was analyzed for incorporation in the blanket assembly. Reliability assessment indicates that it may be possible to double the module in size from 10 to 20 cm in diameter. With a modest increase in coolant pumping power, a blanket assembly comprising 20-cm-diam modules can still achieve 100,000 operating cycles - equivalent to a 3.6-year design lifetime - with only one or two helium coolant leaks into the plasma.« less

TREAT Neutronics Analysis of Water-Loop Concept Accommodating LWR 9-rod Bundle

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

Hill, Connie M.; Woolstenhulme, Nicolas E.; Parry, James R.

Abstract. Simulation of a variety of transient conditions has been successfully achieved in the Transient Reactor Test (TREAT) facility during operation between 1959 and 1994 to support characterization and safety analysis of nuclear fuels and materials. A majority of previously conducted tests were focused on supporting sodium-cooled fast reactor (SFR) designs. Experiments evolved in complexity. Simulation of thermal-hydraulic conditions expected to be encountered by fuels and materials in a reactor environment was realized in the development of TREAT sodium loop experiment vehicles. These loops accommodated up to 7-pin fuel bundles and served to simulate more closely the reactor environment whilemore » safely delivering large quantities of energy into the test specimen. Some of the immediate TREAT restart operations will be focused on testing light water reactor (LWR) accident tolerant fuels (ATF). Similar to the sodium loop objectives, a water loop concept, developed and analyzed in the 1990’s, aimed at achieving thermal-hydraulic conditions encountered in commercial power reactors. The historic water loop concept has been analyzed in the context of a reactivity insertion accident (RIA) simulation for high burnup LWR 2-pin and 3-pin fuel bundles. Findings showed sufficient energy could be deposited into the specimens for evaluation. Similar results of experimental feasibility for the water loop concept (past and present) have recently been obtained using MCNP6.1 with ENDF/B-VII.1 nuclear data libraries. The old water loop concept required only two central TREAT core grid spaces. Preparation for future experiments has resulted in a modified water loop conceptual design designated the TREAT water environment recirculating loop (TWERL). The current TWERL design requires nine TREAT core grid spaces in order to place the water recirculating pump under the TREAT core. Due to the effectiveness of water moderation, neutronics analysis shows that removal of seven additional TREAT fuel elements to facilitate the experiment will not inhibit the ability to successfully simulate a RIA for the 2-pin or 3-pin bundle. This new water loop design leaves room for accommodating a larger fuel pin bundle than previously analyzed. The 7-pin fuel bundle in a hexagonal array with similar spacing of fuel pins in a SFR fuel assembly was considered the minimum needed for one central fuel pin to encounter the most correct thermal conditions. The 9-rod fuel bundle in a square array similar in spacing to pins in a LWR fuel assembly would be considered the LWR equivalent. MCNP analysis conducted on a preliminary LWR 9-rod bundle design shows that sufficient energy deposition into the central pin can be achieved well within range to investigate fuel and cladding performance in a simulated RIA. This is achieved by surrounding the flow channel with an additional annulus of water. Findings also show that a highly significant increase in TREAT to specimen power coupling factor (PCF) within the central pin can be achieved by surrounding the experiment with one to two rings of TREAT upgrade fuel assemblies. The experiment design holds promise for the performance evaluation of PWR fuel at extremely high burnup under similar reactor environment conditions.« less

Layer-by-layer self-assembly in the development of electrochemical energy conversion and storage devices from fuel cells to supercapacitors.

PubMed

Xiang, Yan; Lu, Shanfu; Jiang, San Ping

2012-11-07

As one of the most effective synthesis tools, layer-by-layer (LbL) self-assembly technology can provide a strong non-covalent integration and accurate assembly between homo- or hetero-phase compounds or oppositely charged polyelectrolytes, resulting in highly-ordered nanoscale structures or patterns with excellent functionalities and activities. It has been widely used in the developments of novel materials and nanostructures or patterns from nanotechnologies to medical fields. However, the application of LbL self-assembly in the development of highly efficient electrocatalysts, specific functionalized membranes for proton exchange membrane fuel cells (PEMFCs) and electrode materials for supercapacitors is a relatively new phenomenon. In this review, the application of LbL self-assembly in the development and synthesis of key materials of PEMFCs including polyelectrolyte multilayered proton-exchange membranes, methanol-blocking Nafion membranes, highly uniform and efficient Pt-based electrocatalysts, self-assembled polyelectrolyte functionalized carbon nanotubes (CNTs) and graphenes will be reviewed. The application of LbL self-assembly for the development of multilayer nanostructured materials for use in electrochemical supercapacitors will also be reviewed and discussed (250 references).

Overview of the production of sintered SiC optics and optical sub-assemblies

NASA Astrophysics Data System (ADS)

Williams, S.; Deny, P.

2005-08-01

The following is an overview on sintered silicon carbide (SSiC) material properties and processing requirements for the manufacturing of components for advanced technology optical systems. The overview will compare SSiC material properties to typical materials used for optics and optical structures. In addition, it will review manufacturing processes required to produce optical components in detail by process step. The process overview will illustrate current manufacturing process and concepts to expand the process size capability. The overview will include information on the substantial capital equipment employed in the manufacturing of SSIC. This paper will also review common in-process inspection methodology and design rules. The design rules are used to improve production yield, minimize cost, and maximize the inherent benefits of SSiC for optical systems. Optimizing optical system designs for a SSiC manufacturing process will allow systems designers to utilize SSiC as a low risk, cost competitive, and fast cycle time technology for next generation optical systems.

Thermocouple shield

DOEpatents

Ripley, Edward B [Knoxville, TN

2009-11-24

A thermocouple shield for use in radio frequency fields. In some embodiments the shield includes an electrically conductive tube that houses a standard thermocouple having a thermocouple junction. The electrically conductive tube protects the thermocouple from damage by an RF (including microwave) field and mitigates erroneous temperature readings due to the microwave or RF field. The thermocouple may be surrounded by a ceramic sheath to further protect the thermocouple. The ceramic sheath is generally formed from a material that is transparent to the wavelength of the microwave or RF energy. The microwave transparency property precludes heating of the ceramic sheath due to microwave coupling, which could affect the accuracy of temperature measurements. The ceramic sheath material is typically an electrically insulating material. The electrically insulative properties of the ceramic sheath help avert electrical arcing, which could damage the thermocouple junction. The electrically conductive tube is generally disposed around the thermocouple junction and disposed around at least a portion of the ceramic sheath. The concepts of the thermocouple shield may be incorporated into an integrated shielded thermocouple assembly.

Chemical reactions directed Peptide self-assembly.

PubMed

Rasale, Dnyaneshwar B; Das, Apurba K

2015-05-13

Fabrication of self-assembled nanostructures is one of the important aspects in nanoscience and nanotechnology. The study of self-assembled soft materials remains an area of interest due to their potential applications in biomedicine. The versatile properties of soft materials can be tuned using a bottom up approach of small molecules. Peptide based self-assembly has significant impact in biology because of its unique features such as biocompatibility, straight peptide chain and the presence of different side chain functionality. These unique features explore peptides in various self-assembly process. In this review, we briefly introduce chemical reaction-mediated peptide self-assembly. Herein, we have emphasised enzymes, native chemical ligation and photochemical reactions in the exploration of peptide self-assembly.

Chemical Reactions Directed Peptide Self-Assembly

PubMed Central

Rasale, Dnyaneshwar B.; Das, Apurba K.

2015-01-01

Fabrication of self-assembled nanostructures is one of the important aspects in nanoscience and nanotechnology. The study of self-assembled soft materials remains an area of interest due to their potential applications in biomedicine. The versatile properties of soft materials can be tuned using a bottom up approach of small molecules. Peptide based self-assembly has significant impact in biology because of its unique features such as biocompatibility, straight peptide chain and the presence of different side chain functionality. These unique features explore peptides in various self-assembly process. In this review, we briefly introduce chemical reaction-mediated peptide self-assembly. Herein, we have emphasised enzymes, native chemical ligation and photochemical reactions in the exploration of peptide self-assembly. PMID:25984603

Self-assembly of nanocomposite materials

DOEpatents

Brinker, C. Jeffrey; Sellinger, Alan; Lu, Yunfeng

2001-01-01

A method of making a nanocomposite self-assembly is provided where at least one hydrophilic compound, at least one hydrophobic compound, and at least one amphiphilic surfactant are mixed in an aqueous solvent with the solvent subsequently evaporated to form a self-assembled liquid crystalline mesophase material. Upon polymerization of the hydrophilic and hydrophobic compounds, a robust nanocomposite self-assembled material is formed. Importantly, in the reaction mixture, the amphiphilic surfactant has an initial concentration below the critical micelle concentration to allow formation of the liquid-phase micellar mesophase material. A variety of nanocomposite structures can be formed, depending upon the solvent evaporazation process, including layered mesophases, tubular mesophases, and a hierarchical composite coating composed of an isotropic worm-like micellar overlayer bonded to an oriented, nanolaminated underlayer.

Silicon carbide as a basis for spaceflight optical systems

NASA Astrophysics Data System (ADS)

Curcio, Michael E.

1994-09-01

New advances in the areas of microelectronics and micro-mechanical devices have created a momentum in the development of lightweight, miniaturized, electro-optical space subsystems. The performance improvements achieved and new observational techniques developed as a result, have provided a basis for a new range of Small Explorer, Discovery-class and other low-cost mission concepts for space exploration. However, the ultimate objective of low-mass, inexpensive space science missions will only be achieved with a companion development in the areas of flight optical systems and sensor instrument benches. Silicon carbide (SiC) is currently emerging as an attractive technology to fill this need. As a material basis for reflective, flight telescopes and optical benches, SiC offers: the lightweight and stiffness characteristics of beryllium; glass-like inherent stability consistent with performance to levels of diffraction-limited visible resolution; superior thermal properties down to cryogenic temperatures; and an existing, commercially-based material and processing infrastructure like aluminum. This paper will describe the current status and results of on-going technology developments to utilize these material properties in the creation of lightweight, high- performing, thermally robust, flight optical assemblies. System concepts to be discussed range from an 18 cm aperture, 4-mirror, off-axis system weighing less than 2 kg to a 0.5 m, 15 kg reimager. In addition, results in the development of a thermally-stable, `GOES-like' scan mirror will be presented.

"On the Dot"-The Timing of Self-Assembled Growth to the Quantum Scale.

PubMed

Sonkaria, Sanjiv; Ahn, Sung-Hoon; Lee, Caroline S; Khare, Varsha

2017-06-16

Understanding the complex world of material growth and tunability has mystified the minds of material scientists and has been met with increasing efforts to close the gap between controllability and applicability. The reality of this journey is frustratingly tortuous but is being eased through better conceptual appreciation of metal crystalline frameworks that originate from shape and size dependent solvent responsive growth patterns. The quantum confinement of TiO 2 in the range of 0.8-2 nm has been synthetically challenging to achieve but lessons from biomineralization processes have enabled alternative routes to be explored via self-induced pre-nucleation events. In driving this concept, we have incorporated many of these key features integrating aspects of low temperature annealing at the interface of complex heterogeneous nucleation between hard and soft materials to arrest the biomimetic amorphous phase of TiO 2 to a tunable crystalline quantumized state. The stabilization of metastable states of quantum sized TiO 2 driven by kinetic and thermodynamic processes show hallmarks of biomineralized controlled events that suggest the inter-play between new pathways and interfacial energies that preferentially favor low dimensionality at the quantum scale. This provides the potential to re-direct synthetic assemblies under tightly controlled parameters to generate a host of new materials with size, shape and anisotropic properties as smart stimuli responsive materials. These new stabilities leading to the growth arrest of TiO 2 are discussed in terms of molecular interactions and structural frameworks that were previously inaccessible via conventional routes. There exists an undiscovered parallel between synthetic and biomineralized routes enabling unprecedented access to the availability and tunability of novel quantum confined materials. The parametrics of complex material design at the crossroads of synthetically and biologically driven processes is only now surfacing. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structure of a designed protein cage that self-assembles into a highly porous cube

DOE PAGES

Lai, Yen-Ting; Reading, Eamonn; Hura, Greg L.; ...

2014-11-10

Natural proteins can be versatile building blocks for multimeric, self-assembling structures. Yet, creating protein-based assemblies with specific geometries and chemical properties remains challenging. Highly porous materials represent particularly interesting targets for designed assembly. Here we utilize a strategy of fusing two natural protein oligomers using a continuous alpha-helical linker to design a novel protein that self assembles into a 750 kDa, 225 Å diameter, cube-shaped cage with large openings into a 130 Å diameter inner cavity. A crystal structure of the cage showed atomic level agreement with the designed model, while electron microscopy, native mass spectrometry, and small angle x-raymore » scattering revealed alternate assembly forms in solution. These studies show that accurate design of large porous assemblies with specific shapes is feasible, while further specificity improvements will likely require limiting flexibility to select against alternative forms. Finally, these results provide a foundation for the design of advanced materials with applications in bionanotechnology, nanomedicine and material sciences.« less

Application of type synthesis theory to the redesign of a complex surgical instrument.

PubMed

Lim, Jonas J B; Erdman, Arthur G

2002-06-01

Surgical instruments consist of basic mechanical components such as gears, links, pivots, sliders, etc., which are common in mechanical design. This paper describes the application of a method in the analysis and design of complex surgical instruments such as those employed in laparoscopic surgery. This is believed to be the first application of type synthesis theory to a complex medical instrument. Type synthesis is a methodology that can be applied during the conceptual phase of mechanical design. A handle assembly from a patented laparoscopic surgical stapler is used to illustrate the application of the design method developed. Type synthesis is applied on specific subsystems of the mechanism within the handle assembly where alternative design concepts are generated. Chosen concepts are then combined to form a new conceptual design for the handle assembly. The new handle assembly is improved because it has fewer number of parts, is a simpler design and is easier to assemble. Surgical instrument designers may use the methodology presented here to analyze the mechanical subsystems within complex instruments and to create new options that may offer improvements to the original design.

Self-Assembled Materials Made from Functional Recombinant Proteins.

PubMed

Jang, Yeongseon; Champion, Julie A

2016-10-18

Proteins are potent molecules that can be used as therapeutics, sensors, and biocatalysts with many advantages over small-molecule counterparts due to the specificity of their activity based on their amino acid sequence and folded three-dimensional structure. However, they also have significant limitations in their stability, localization, and recovery when used in soluble form. These opportunities and challenges have motivated the creation of materials from such functional proteins in order to protect and present them in a way that enhances their function. We have designed functional recombinant fusion proteins capable of self-assembling into materials with unique structures that maintain or improve the functionality of the protein. Fusion of either a functional protein or an assembly domain to a leucine zipper domain makes the materials design strategy modular, based on the high affinity between leucine zippers. The self-assembly domains, including elastin-like polypeptides (ELPs) and defined-sequence random coil polypeptides, can be fused with a leucine zipper motif in order to promote assembly of the fusion proteins into larger structures upon specific stimuli such as temperature and ionic strength. Fusion of other functional domains with the counterpart leucine zipper motif endows the self-assembled materials with protein-specific functions such as fluorescence or catalytic activity. In this Account, we describe several examples of materials assembled from functional fusion proteins as well as the structural characterization, functionality, and understanding of the assembly mechanism. The first example is zipper fusion proteins containing ELPs that assemble into particles when introduced to a model extracellular matrix and subsequently disassemble over time to release the functional protein for drug delivery applications. Under different conditions, the same fusion proteins can self-assemble into hollow vesicles. The vesicles display a functional protein on the surface and can also carry protein, small-molecule, or nanoparticle cargo in the vesicle lumen. To create a material with a more complex hierarchical structure, we combined calcium phosphate with zipper fusion proteins containing random coil polypeptides to produce hybrid protein-inorganic supraparticles with high surface area and porous structure. The use of a functional enzyme created supraparticles with the ability to degrade inflammatory cytokines. Our characterization of these protein materials revealed that the molecular interactions are complex because of the large size of the protein building blocks, their folded structures, and the number of potential interactions including hydrophobic interactions, electrostatic interactions, van der Waals forces, and specific affinity-based interactions. It is difficult or even impossible to predict the structures a priori. However, once the basic assembly principles are understood, there is opportunity to tune the material properties, such as size, through control of the self-assembly conditions. Our future efforts on the fundamental side will focus on identifying the phase space of self-assembly of these fusion proteins and additional experimental levers with which to control and tune the resulting materials. On the application side, we are investigating an array of different functional proteins to expand the use of these structures in both therapeutic protein delivery and biocatalysis.

Assembly for collecting samples for purposes of identification or analysis and method of use

DOEpatents

Thompson, Cyril V [Knoxville, TN; Smith, Rob R [Knoxville, TN

2010-02-02

An assembly and an associated method for collecting a sample of material desired to be characterized with diagnostic equipment includes or utilizes an elongated member having a proximal end with which the assembly is manipulated by a user and a distal end. In addition, a collection tip which is capable of being placed into contact with the material to be characterized is supported upon the distal end. The collection tip includes a body of chemically-inert porous material for binding a sample of material when the tip is placed into contact with the material and thereby holds the sample of material for subsequent introduction to the diagnostic equipment.

AHTR Mechanical, Structural, and Neutronic Preconceptual Design

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

Varma, V.K.; Holcomb, D.E.; Peretz, F.J.

2012-09-15

This report provides an overview of the mechanical, structural, and neutronic aspects of the Advanced High Temperature Reactor (AHTR) design concept. The AHTR is a design concept for a large output Fluoride salt cooled High-temperature Reactor (FHR) that is being developed to enable evaluation of the technology hurdles remaining to be overcome prior to FHRs becoming an option for commercial reactor deployment. This report documents the incremental AHTR design maturation performed over the past year and is focused on advancing the design concept to a level of a functional, self-consistent system. The reactor concept development remains at a preconceptual levelmore » of maturity. While the overall appearance of an AHTR design is anticipated to be similar to the current concept, optimized dimensions will differ from those presented here. The AHTR employs plate type coated particle fuel assemblies with rapid, off-line refueling. Neutronic analysis of the core has confirmed the viability of a 6-month two-batch cycle with 9 wt. % enriched uranium fuel. Refueling is intended to be performed automatically under visual guidance using dedicated robotic manipulators. The report includes a preconceptual design of the manipulators, the fuel transfer system, and the used fuel storage system. The present design intent is for used fuel to be stored inside of containment for at least six months and then transferred to local dry wells for intermediate term, on-site storage. The mechanical and structural concept development effort has included an emphasis on transportation and constructability to minimize construction costs and schedule. The design intent is that all components be factory fabricated into rail transportable modules that are assembled into subsystems at an on-site workshop prior to being lifted into position using a heavy-lift crane in an open-top style construction. While detailed accident identification and response sequence analysis has yet to be performed, the design concept incorporates fully passive responses to all identified design basis or non-very-low frequency beyond design basis accidents as well as multiple levels of radioactive material containment. Key building design elements include (1) below grade siting to minimize vulnerability to aircraft impact, (2) multiple natural circulation decay heat rejection chimneys, (3) seismic base isolation, and (4) decay heat powered back-up electricity generation.« less

Self-assembling biomolecular catalysts for hydrogen production

NASA Astrophysics Data System (ADS)

Jordan, Paul C.; Patterson, Dustin P.; Saboda, Kendall N.; Edwards, Ethan J.; Miettinen, Heini M.; Basu, Gautam; Thielges, Megan C.; Douglas, Trevor

2016-02-01

The chemistry of highly evolved protein-based compartments has inspired the design of new catalytically active materials that self-assemble from biological components. A frontier of this biodesign is the potential to contribute new catalytic systems for the production of sustainable fuels, such as hydrogen. Here, we show the encapsulation and protection of an active hydrogen-producing and oxygen-tolerant [NiFe]-hydrogenase, sequestered within the capsid of the bacteriophage P22 through directed self-assembly. We co-opted Escherichia coli for biomolecular synthesis and assembly of this nanomaterial by expressing and maturing the EcHyd-1 hydrogenase prior to expression of the P22 coat protein, which subsequently self assembles. By probing the infrared spectroscopic signatures and catalytic activity of the engineered material, we demonstrate that the capsid provides stability and protection to the hydrogenase cargo. These results illustrate how combining biological function with directed supramolecular self-assembly can be used to create new materials for sustainable catalysis.

Aerobrake assembly with minimum Space Station accommodation

NASA Technical Reports Server (NTRS)

Katzberg, Steven J.; Butler, David H.; Doggett, William R.; Russell, James W.; Hurban, Theresa

1991-01-01

The minimum Space Station Freedom accommodations required for initial assembly, repair, and refurbishment of the Lunar aerobrake were investigated. Baseline Space Station Freedom support services were assumed, as well as reasonable earth-to-orbit possibilities. A set of three aerobrake configurations representative of the major themes in aerobraking were developed. Structural assembly concepts, along with on-orbit assembly and refurbishment scenarios were created. The scenarios were exercised to identify required Space Station Freedom accommodations. Finally, important areas for follow-on study were also identified.

Fabrication of fuel pin assemblies, phase 3

NASA Technical Reports Server (NTRS)

Keeton, A. R.; Stemann, L. G.

1972-01-01

Five full size and eight reduced length fuel pins were fabricated for irradiation testing to evaluate design concepts for a fast spectrum lithium cooled compact space power reactor. These assemblies consisted of uranium mononitride fuel pellets encased in a T-111 (Ta-8W-2Hf) clad with a tungsten barrier separating fuel and clad. Fabrication procedures were fully qualified by process development and assembly qualification tests. Detailed specifications and procedures were written for the fabrication and assembly of prototype fuel pins.

Multidimensional Self-Assembled Structures of Alkylated Cellulose Oligomers Synthesized via in Vitro Enzymatic Reactions.

PubMed

Yataka, Yusuke; Sawada, Toshiki; Serizawa, Takeshi

2016-10-04

The self-assembly of biomolecules into highly ordered nano-to-macroscale structures is essential in the construction of biological tissues and organs. A variety of biomolecular assemblies composed of nucleic acids, peptides, and lipids have been used as molecular building units for self-assembled materials. However, crystalline polysaccharides have rarely been utilized in self-assembled materials. In this study, we describe multidimensional self-assembled structures of alkylated cellulose oligomers synthesized via in vitro enzymatic reactions. We found that the alkyl chain length drastically affected the assembled morphologies and allomorphs of cellulose moieties. The modulation of the intermolecular interactions of cellulose oligomers by alkyl substituents was highly effective at controlling their assembly into multidimensional structures. This study proposes a new potential of crystalline oligosaccharides for structural components of molecular assemblies with controlled morphologies and crystal structures.

Pultrusion Die Assembly

NASA Technical Reports Server (NTRS)

Wilson, Maywood L. (Inventor); Johnson, Gary S. (Inventor); Frye, Mark W. (Inventor); Stanfield, Clarence E. (Inventor)

1988-01-01

This invention relates generally to pultrusion die assemblies, and more particularly, to a pultrusion die assembly which incorporates a plurality of functions in order to produce a continuous, thin composite fiber reinforced thermoplastic material. The invention is useful for making high performance thermoplastic composite materials in sheets which can be coiled on a spool and stored for further processing.

Nanocrystalline Precursors for the Co-Assembly of Crack-Free Metal Oxide Inverse Opals.

PubMed

Phillips, Katherine R; Shirman, Tanya; Shirman, Elijah; Shneidman, Anna V; Kay, Theresa M; Aizenberg, Joanna

2018-05-01

Inorganic microstructured materials are ubiquitous in nature. However, their formation in artificial self-assembly systems is challenging as it involves a complex interplay of competing forces during and after assembly. For example, colloidal assembly requires fine-tuning of factors such as the size and surface charge of the particles and electrolyte strength of the solvent to enable successful self-assembly and minimize crack formation. Co-assembly of templating colloidal particles together with a sol-gel matrix precursor material helps to release stresses that accumulate during drying and solidification, as previously shown for the formation of high-quality inverse opal (IO) films out of amorphous silica. Expanding this methodology to crystalline materials would result in microscale architectures with enhanced photonic, electronic, and catalytic properties. This work describes tailoring the crystallinity of metal oxide precursors that enable the formation of highly ordered, large-area (mm 2 ) crack-free titania, zirconia, and alumina IO films. The same bioinspired approach can be applied to other crystalline materials as well as structures beyond IOs. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Molecular Clusters: Nanoscale Building Blocks for Solid-State Materials.

PubMed

Pinkard, Andrew; Champsaur, Anouck M; Roy, Xavier

2018-04-17

The programmed assembly of nanoscale building blocks into multicomponent hierarchical structures is a powerful strategy for the bottom-up construction of functional materials. To develop this concept, our team has explored the use of molecular clusters as superatomic building blocks to fabricate new classes of materials. The library of molecular clusters is rich with exciting properties, including diverse functionalization, redox activity, and magnetic ordering, so the resulting cluster-assembled solids, which we term superatomic crystals (SACs), hold the promise of high tunability, atomic precision, and robust architectures among a diverse range of other material properties. Molecular clusters have only seldom been used as precursors for functional materials. Our team has been at the forefront of new developments in this exciting research area, and this Account focuses on our progress toward designing materials from cluster-based precursors. In particular, this Account discusses (1) the design and synthesis of molecular cluster superatomic building blocks, (2) their self-assembly into SACs, and (3) their resulting collective properties. The set of molecular clusters discussed herein is diverse, with different cluster cores and ligand arrangements to create an impressive array of solids. The cluster cores include octahedral M 6 E 8 and cubane M 4 E 4 (M = metal; E = chalcogen), which are typically passivated by a shell of supporting ligands, a feature upon which we have expanded upon by designing and synthesizing more exotic ligands that can be used to direct solid-state assembly. Building from this library, we have designed whole families of binary SACs where the building blocks are held together through electrostatic, covalent, or van der Waals interactions. Using single-crystal X-ray diffraction (SCXRD) to determine the atomic structure, a remarkable range of compositional variability is accessible. We can also use this technique, in tandem with vibrational spectroscopy, to ascertain features about the constituent superatomic building blocks, such as the charge of the cluster cores, by analysis of bond distances from the SCXRD data. The combination of atomic precision and intercluster interactions in these SACs produces novel collective properties, including tunable electrical transport, crystalline thermal conductivity, and ferromagnetism. In addition, we have developed a synthetic strategy to insert redox-active guests into the superstructure of SACs via single-crystal-to-single-crystal intercalation. This intercalation process allows us to tune the optical and electrical transport properties of the superatomic crystal host. These properties are explored using a host of techniques, including Raman spectroscopy, SQUID magnetometry, electrical transport measurements, electronic absorption spectroscopy, differential scanning calorimetry, and frequency-domain thermoreflectance. Superatomic crystals have proven to be both robust and tunable, representing a new method of materials design and architecture. This Account demonstrates how precisely controlling the structure and properties of nanoscale building blocks is key in developing the next generation of functional materials; several examples are discussed and detailed herein.

Challenges and advances in the field of self-assembled membranes.

PubMed

van Rijn, Patrick; Tutus, Murat; Kathrein, Christine; Zhu, Leilei; Wessling, Matthias; Schwaneberg, Ulrich; Böker, Alexander

2013-08-21

Self-assembled membranes are of vital importance in biological systems e.g. cellular and organelle membranes, however, more focus is being put on synthetic self-assembled membranes not only as an alternative for lipid membranes but also as an alternative for lithographic methods. More investigations move towards self-assembly processes because of the low-cost preparations, structural self-regulation and the ease of creating composite materials and tunable properties. The fabrication of new smart membrane materials via self-assembly is of interest for delivery vessels, size selective separation and purification, controlled-release materials, sensors and catalysts, scaffolds for tissue engineering, low dielectric constant materials for microelectronic devices, antireflective coatings and proton exchange membranes for polymer electrolyte membrane fuel cells. Polymers and nanoparticles offer the most straightforward approaches to create membrane structures. However, alternative approaches using small molecules or composite materials offer novel ultra-thin membranes or multi-functional membranes, respectively. Especially, the composite material membranes are regarded as highly promising since they offer the possibility to combine properties of different systems. The advantages of polymers which provide elastic and flexible yet stable matrices can be combined with nanoparticles being either inorganic, organic or even protein-based which offers pore-size control, catalytic activity or permeation regulation. It is therefore believed that at the interface of different disciplines with each offering different materials or approaches, the most novel and interesting membrane structures are going to be produced. The combinations and approaches presented in this review offer non-conventional self-assembled membrane materials which exhibit a high potential to advance membrane science and find more practical applications.

Target Assembly to Check Boresight Alignment of Active Sensors

NASA Technical Reports Server (NTRS)

Ramos-Izquierdo, Luis; Scott, V. Stanley; Riris, Haris; Cavanaugh, John; Liiva, Peter; Rodriguez, Michael

2011-01-01

A compact and portable target assembly (Fig. 1) has been developed to measure the boresite alignment of LRO's Lunar Orbiter Laser Altimeter (LOLA) instrument at the spacecraft level. The concept for this target assembly has evolved over many years with earlier versions used to test the Mars Observer Laser Altimeter (MOLA), the Geoscience Laser Altimeter System (GLAS), and the Mercury Laser Altimeter (MLA) space-based instruments.

Traffic model for commercial payloads in the Materials Experiment Assembly (MEA). [market research in commercial space processing

NASA Technical Reports Server (NTRS)

Tietzel, F. A.

1979-01-01

One hundred individuals representing universities, technical institutes, government agencies, and industrial facilities were surveyed to determine potential commercial use of a self-contained, automated assembly for the space processing of materials during frequent shuttle flights for the 1981 to 1987 period. The approach used and the results of the study are summarized. A time time-phased projection (traffic model) of commercial usage of the materials experiment assembly is provided.

Multicomponent self-assembly as a tool to harness new properties from peptides and proteins in material design.

PubMed

Okesola, Babatunde O; Mata, Alvaro

2018-05-21

Nature is enriched with a wide variety of complex, synergistic, and highly functional protein-based multicomponent assemblies. As such, nature has served as a source of inspiration for using multicomponent self-assembly as a platform to create highly ordered, complex, and dynamic protein and peptide-based nanostructures. Such an assembly system relies on the initial interaction of distinct individual building blocks leading to the formation of a complex that subsequently assembles into supramolecular architectures. This approach not only serves as a powerful platform for gaining insight into how proteins co-assemble in nature but also offers huge opportunities to harness new properties not inherent in the individual building blocks. In the past decades, various multicomponent self-assembly strategies have been used to extract synergistic properties from proteins and peptides. This review highlights the updates in the field of multicomponent self-assembly of proteins and peptides and summarizes various strategies, including covalent conjugation, ligand-receptor interactions, templated/directed assembly and non-specific co-assembly, for driving the self-assembly of multiple proteins and peptide-based building blocks into functional materials. In particular, we focus on peptide- or protein-containing multicomponent systems that, upon self-assembly, enable the emergence of new properties or phenomena. The ultimate goal of this review is to highlight the importance of multicomponent self-assembly in protein and peptide engineering, and to advocate its growth in the fields of materials science and nanotechnology.

Spatially selective assembly of quantum dot light emitters in an LED using engineered peptides.

PubMed

Demir, Hilmi Volkan; Seker, Urartu Ozgur Safak; Zengin, Gulis; Mutlugun, Evren; Sari, Emre; Tamerler, Candan; Sarikaya, Mehmet

2011-04-26

Semiconductor nanocrystal quantum dots are utilized in numerous applications in nano- and biotechnology. In device applications, where several different material components are involved, quantum dots typically need to be assembled at explicit locations for enhanced functionality. Conventional approaches cannot meet these requirements where assembly of nanocrystals is usually material-nonspecific, thereby limiting the control of their spatial distribution. Here we demonstrate directed self-assembly of quantum dot emitters at material-specific locations in a color-conversion LED containing several material components including a metal, a dielectric, and a semiconductor. We achieve a spatially selective immobilization of quantum dot emitters by using the unique material selectivity characteristics provided by the engineered solid-binding peptides as smart linkers. Peptide-decorated quantum dots exhibited several orders of magnitude higher photoluminescence compared to the control groups, thus, potentially opening up novel ways to advance these photonic platforms in applications ranging from chemical to biodetection.

Effects of materials and design on the criticality and shielding assessment of canister concepts for the disposal of spent nuclear fuel.

PubMed

Gutiérrez, Miguel Morales; Caruso, Stefano; Diomidis, Nikitas

2018-05-19

According to the Swiss disposal concept, the safety of a deep geological repository for spent nuclear fuel (SNF) is based on a multi-barrier system. The disposal canister is an important component of the engineered barrier system, aiming to provide containment of the SNF for thousands of years. This study evaluates the criticality safety and shielding of candidate disposal canister concepts, focusing on the fulfilment of the sub-criticality criterion and on limiting radiolysis processes at the outer surface of the canister which can enhance corrosion mechanisms. The effective neutron multiplication factor (k-eff) and the surface dose rates are calculated for three different canister designs and material combinations for boiling water reactor (BWR) canisters, containing 12 spent fuel assemblies (SFA), and pressurized water reactor (PWR) canisters, with 4 SFAs. For each configuration, individual criticality and shielding calculations were carried out. The results show that k-eff falls below the defined upper safety limit (USL) of 0.95 for all BWR configurations, while staying above USL for the PWR ones. Therefore, the application of a burnup credit methodology for the PWR case is required, being currently under development. Relevant is also the influence of canister material and internal geometry on criticality, enabling the identification of safer fuel arrangements. For a final burnup of 55MWd/kgHM and 30y cooling time, the combined photon-neutron surface dose rate is well below the threshold of 1 Gy/h defined to limit radiation-induced corrosion of the canister in all cases. Copyright © 2018 Elsevier Ltd. All rights reserved.

A Gimbal sizing analysis for an IPACS rotating assembly

NASA Technical Reports Server (NTRS)

Burke, P. R.; Coronato, P. A.

1985-01-01

All major components of an integrated power/attitude control system (IPACS) assembly were analyzed for testing, launch, and operational stresses. The conceptual design for the outer gimbal and mounting ring structures were developed and analyzed along with preliminary designs of the pivot and torquer assemblies. Results from the system response analysis and the thermal analysis are also presented. Gimballing of this rotating assembly should present few difficulties as the maximum gimballing rate is quite low. However, the inner gimbal assembly in its current configuration must be modified to develop the system from a laboratory concept to a realistic flight hardware status.

A&R challenges for in-space operations. [Automation and Robotic technologies

NASA Technical Reports Server (NTRS)

Underwood, James

1990-01-01

Automation and robotics (A&R) challenges for in-space operations are examined, with emphasis on the interaction between developing requirements, developing solutions, design concepts, and the nature of the applicability of automation in robotic technologies. Attention is first given to the use of A&R in establishing outposts on the moon and Mars. Then emphasis is placed on the requirements for the assembly of transportation systems in low earth orbit. Concepts of the Space Station which show how the assembly, processing, and checkout of systems in LEO might be accommodated are examined.

jsc2018m000297_Investigation_Seeks_to_Create_Self-Assembling_Materials-MP4

NASA Image and Video Library

2018-05-14

Investigation Seeks to Create Self-Assembling Materials------ As we travel farther into space, clever solutions to problems like engine part malfunctions and other possible mishaps will be a vital part of the planning process. 3D printing, or additive manufacturing, is an emerging technology that may be used to custom-create mission-critical parts. An integral piece of this process is understanding how particle shape, size distribution and packing behavior affect the manufacturing process. The Advanced Colloids Experiment-Temperature-7 investigation (ACE-T-7) aboard the International Space Station explores the feasibility of creating self-assembling microscopic particles for use in the manufacturing of materials during spaceflight. Read more about ACE-T-& here: https://www.nasa.gov/feature/investigation-seeks-to-create-self-assembling-materials

Novel In-Space Manufacturing Concepts for the Development of Large Space Telescopes

NASA Technical Reports Server (NTRS)

Mooney, James T.; Reardon, Patrick; Gregory Don; Manning, Andrew; Blackmon, Jim; Howsman, Tom; Williams, Philip; Brantley, Whitt; Rakoczy, John; Herren, Kenneth

2006-01-01

There is a continuous demand for larger, lighter, and higher quality telescopes. Over the past several decades, we have seen the evolution from launchable 2 meter-class telescopes (such as Hubble), to today s demand for deployable 6 meter-class telescopes (such as JWST), to tomorrow s need for up to 150 meter-class telescopes. As the apertures continue to grow, it will become much more difficult and expensive to launch assembled telescope structures. To address this issue, we are seeing the emergence of new novel structural concepts, such as inflatable structures and membrane optics. While these structural concepts do show promise, it is very difficult to achieve and maintain high surface figure quality. Another potential solution to develop large space telescopes is to move the fabrication facility into space and launch the raw materials. In this paper we present initial in-space manufacturing concepts to enable the development of large telescopes. This includes novel approaches for the fabrication of both the optical elements and the telescope support structure. We will also discuss potential optical designs for large space telescopes and describe their relation to the fabrication methods. These concepts are being developed to meet the demanding requirements of DARPA s LASSO (Large Aperture Space Surveillance Optic) program which currently requires a 150 meter optical aperture with a 17 degree field of view.

Modular Self-Assembly of Protein Cage Lattices for Multistep Catalysis

DOE PAGES

Uchida, Masaki; McCoy, Kimberly; Fukuto, Masafumi; ...

2017-11-13

The assembly of individual molecules into hierarchical structures is a promising strategy for developing three-dimensional materials with properties arising from interaction between the individual building blocks. Virus capsids are elegant examples of biomolecular nanostructures, which are themselves hierarchically assembled from a limited number of protein subunits. Here, we demonstrate the bio-inspired modular construction of materials with two levels of hierarchy: the formation of catalytically active individual virus-like particles (VLPs) through directed self-assembly of capsid subunits with enzyme encapsulation, and the assembly of these VLP building blocks into three-dimensional arrays. The structure of the assembled arrays was successfully altered from anmore » amorphous aggregate to an ordered structure, with a face-centered cubic lattice, by modifying the exterior surface of the VLP without changing its overall morphology, to modulate interparticle interactions. The assembly behavior and resultant lattice structure was a consequence of interparticle interaction between exterior surfaces of individual particles and thus independent of the enzyme cargos encapsulated within the VLPs. These superlattice materials, composed of two populations of enzyme-packaged VLP modules, retained the coupled catalytic activity in a two-step reaction for isobutanol synthesis. As a result, this study demonstrates a significant step toward the bottom-up fabrication of functional superlattice materials using a self-assembly process across multiple length scales and exhibits properties and function that arise from the interaction between individual building blocks.« less

Modular Self-Assembly of Protein Cage Lattices for Multistep Catalysis

PubMed Central

Uchida, Masaki; McCoy, Kimberly; Fukuto, Masafumi; Yang, Lin; Yoshimura, Hideyuki; Miettinen, Heini M.; LaFrance, Ben; Patterson, Dustin P.; Schwarz, Benjamin; Karty, Jonathan A.; Prevelige, Peter E.; Lee, Byeongdu; Douglas, Trevor

2018-01-01

The assembly of individual molecules into hierarchical structures is a promising strategy for developing three-dimensional materials with properties arising from interaction between the individual building blocks. Virus capsids are elegant examples of biomolecular nanostructures, which are themselves hierarchically assembled from a limited number of protein subunits. Here we demonstrate the bio-inspired modular construction of materials with two levels of hierarchy; the formation of catalytically active individual virus-like particles (VLPs) through directed self-assembly of capsid subunits with enzyme encapsulation, and the assembly of these VLP building blocks into three-dimensional arrays. The structure of the assembled arrays was successfully altered from an amorphous aggregate to an ordered structure, with a face-centered cubic lattice, by modifying the exterior surface of the VLP without changing its overall morphology, to modulate interparticle interactions. The assembly behavior and resultant lattice structure was a consequence of interparticle interaction between exterior surfaces of individual particles, and thus independent of the enzyme cargos encapsulated within the VLPs. These superlattice materials, composed of two populations of enzyme packaged VLP modules, retained the coupled catalytic activity in a two-step reaction for isobutanol synthesis. This study demonstrates a significant step toward the bottom-up fabrication of functional superlattice materials using a self-assembly process across multiple length scales, and exhibits properties and function that arise from the interaction between individual building blocks. PMID:29131580

Modular Self-Assembly of Protein Cage Lattices for Multistep Catalysis

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

Uchida, Masaki; McCoy, Kimberly; Fukuto, Masafumi

The assembly of individual molecules into hierarchical structures is a promising strategy for developing three-dimensional materials with properties arising from interaction between the individual building blocks. Virus capsids are elegant examples of biomolecular nanostructures, which are themselves hierarchically assembled from a limited number of protein subunits. Here, we demonstrate the bio-inspired modular construction of materials with two levels of hierarchy: the formation of catalytically active individual virus-like particles (VLPs) through directed self-assembly of capsid subunits with enzyme encapsulation, and the assembly of these VLP building blocks into three-dimensional arrays. The structure of the assembled arrays was successfully altered from anmore » amorphous aggregate to an ordered structure, with a face-centered cubic lattice, by modifying the exterior surface of the VLP without changing its overall morphology, to modulate interparticle interactions. The assembly behavior and resultant lattice structure was a consequence of interparticle interaction between exterior surfaces of individual particles and thus independent of the enzyme cargos encapsulated within the VLPs. These superlattice materials, composed of two populations of enzyme-packaged VLP modules, retained the coupled catalytic activity in a two-step reaction for isobutanol synthesis. As a result, this study demonstrates a significant step toward the bottom-up fabrication of functional superlattice materials using a self-assembly process across multiple length scales and exhibits properties and function that arise from the interaction between individual building blocks.« less

Self-assembled materials and supramolecular chemistry within microfluidic environments: from common thermodynamic states to non-equilibrium structures.

PubMed

Sevim, S; Sorrenti, A; Franco, C; Furukawa, S; Pané, S; deMello, A J; Puigmartí-Luis, J

2018-05-01

Self-assembly is a crucial component in the bottom-up fabrication of hierarchical supramolecular structures and advanced functional materials. Control has traditionally relied on the use of encoded building blocks bearing suitable moieties for recognition and interaction, with targeting of the thermodynamic equilibrium state. On the other hand, nature leverages the control of reaction-diffusion processes to create hierarchically organized materials with surprisingly complex biological functions. Indeed, under non-equilibrium conditions (kinetic control), the spatio-temporal command of chemical gradients and reactant mixing during self-assembly (the creation of non-uniform chemical environments for example) can strongly affect the outcome of the self-assembly process. This directly enables a precise control over material properties and functions. In this tutorial review, we show how the unique physical conditions offered by microfluidic technologies can be advantageously used to control the self-assembly of materials and of supramolecular aggregates in solution, making possible the isolation of intermediate states and unprecedented non-equilibrium structures, as well as the emergence of novel functions. Selected examples from the literature will be used to confirm that microfluidic devices are an invaluable toolbox technology for unveiling, understanding and steering self-assembly pathways to desired structures, properties and functions, as well as advanced processing tools for device fabrication and integration.

High thermoelectric properties of (Sb, Bi)2Te3 nanowire arrays by tilt-structure engineering

NASA Astrophysics Data System (ADS)

Tan, Ming; Hao, Yanming; Deng, Yuan; Chen, Jingyi

2018-06-01

In this paper, we present an innovative tilt-structure design concept for (Sb, Bi)2Te3 nanowire array assembled by high-quality nanowires with well oriented growth, utilizing a simple vacuum thermal evaporation technique. The unusual tilt-structure (Sb, Bi)2Te3 nanowire array with a tilted angle of 45° exhibits a high thermoelectric dimensionless figure-of-merit ZT = 1.72 at room temperature. The relatively high ZT value in contrast to that of previously reported (Sb, Bi)2Te3 materials and the vertical (Sb, Bi)2Te3 nanowire arrays evidently reveals the crucial role of the unique tilt-structure in favorably influencing carrier and phonon transport properties, resulting in a significantly improved ZT value. The transport mechanism of such tilt-structure is proposed and investigated. This method opens a new approach to optimize nano-structure in thin films for next-generation thermoelectric materials and devices.

Chiral optical response of planar and symmetric nanotrimers enabled by heteromaterial selection.

PubMed

Banzer, Peter; Woźniak, Paweł; Mick, Uwe; De Leon, Israel; Boyd, Robert W

2016-10-13

Chirality is an intriguing property of certain molecules, materials or artificial nanostructures, which allows them to interact with the spin angular momentum of the impinging light field. Due to their chiral geometry, they can distinguish between left- and right-hand circular polarization states or convert them into each other. Here we introduce an approach towards optical chirality, which is observed in individual two-dimensional and geometrically mirror-symmetric nanostructures. In this scheme, the chiral optical response is induced by the chosen heterogeneous material composition of a particle assembly and the corresponding resonance behaviour of the constituents it is built from, which breaks the symmetry of the system. As a proof of principle, we investigate such a structure composed of individual silicon and gold nanoparticles both experimentally, as well as numerically. Our proposed concept constitutes an approach for designing two-dimensional chiral media tailored at the nanoscale, allowing for high tunability of their optical response.

RTAPS (Research and Technology for Aerospace Propulsion Systems): Simulation of Structural Loads within a Hybrid Gear Resulting From Loading at the Gear Teeth

NASA Technical Reports Server (NTRS)

Naffin, Richard K.; Ulun, Umut; Garmel, Charles D.; McManus, Nika; Hu, Zhenning; Ohlerking, Westin B.; Myers, David E.

2017-01-01

This report investigates the practical usage of hybrid structures for rotorcraft gearing. The primary driver for utilizing hybrid structures for rotorcraft gearing is to reduce the drive system weight. The hybrid structure concept featured in this study for rotorcraft gearing consists of a metallic gear tooth-rim, a web section manufactured from composite materials, and a metallic hub. The metallic gear tooth-rim is manufactured from conventional gear steel alloys, such as AISI 9310. The gear tooth-rim attaches to the outer diameter of the web section made from composite materials. The inner diameter of the composite web can then attach to a metallic hub, completing the assembly. It is assumed that areas of the shafting or hub where rolling element bearings may ride must remain as gear steel alloys for this study.

Self-assembled photosynthesis-inspired light harvesting material and solar cells containing the same

DOEpatents

Lindsey, Jonathan S [Raleigh, NC; Chinnasamy, Muthiah [Raleigh, NC; Fan, Dazhong [Raleigh, NC

2009-12-15

A solar cell is described that comprises: (a) a semiconductor charge separation material; (b) at least one electrode connected to the charge separation material; and (c) a light-harvesting film on the charge separation material, the light-harvesting film comprising non-covalently coupled, self-assembled units of porphyrinic macrocycles. The porphyrinic macrocycles preferably comprise: (i) an intramolecularly coordinated metal; (ii) a first coordinating substituent; and (iii) a second coordinating substituent opposite the first coordinating substituent. The porphyrinic macrocycles can be assembled by repeating intermolecular coordination complexes of the metal, the first coordinating substituent and the second coordinating substituent.

Process and assembly plans for low cost commercial fuselage structure

NASA Technical Reports Server (NTRS)

Willden, Kurtis; Metschan, Stephen; Starkey, Val

1991-01-01

Cost and weight reduction for a composite structure is a result of selecting design concepts that can be built using efficient low cost manufacturing and assembly processes. Since design and manufacturing are inherently cost dependent, concurrent engineering in the form of a Design-Build Team (DBT) is essential for low cost designs. Detailed cost analysis from DBT designs and hardware verification must be performed to identify the cost drivers and relationships between design and manufacturing processes. Results from the global evaluation are used to quantitatively rank design, identify cost centers for higher ranking design concepts, define and prioritize a list of technical/economic issues and barriers, and identify parameters that control concept response. These results are then used for final design optimization.

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

NASA Astrophysics Data System (ADS)

Li, Xiuyun; Yu, Changyong

2018-06-01

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

ARO-YIP (Materials By Design): Organic Photovoltaic Multiferroics

DTIC Science & Technology

Materials-by- design and self-assembly principles are applied to organic functional materials to control their morphology, interface, and crystalline...multifunctional properties, such as dielectric, magnetic, optoelectronic, and magnetoelectric coupling behaviors. The control of organic crystallization and...electronics. In this project, we aim at utilizing the material design and assembly strategies to rationally develop organic multiferroic-photovoltaics

Graded porous inorganic materials derived from self-assembled block copolymer templates.

PubMed

Gu, Yibei; Werner, Jörg G; Dorin, Rachel M; Robbins, Spencer W; Wiesner, Ulrich

2015-03-19

Graded porous inorganic materials directed by macromolecular self-assembly are expected to offer unique structural platforms relative to conventional porous inorganic materials. Their preparation to date remains a challenge, however, based on the sparsity of viable synthetic self-assembly pathways to control structural asymmetry. Here we demonstrate the fabrication of graded porous carbon, metal, and metal oxide film structures from self-assembled block copolymer templates by using various backfilling techniques in combination with thermal treatments for template removal and chemical transformations. The asymmetric inorganic structures display mesopores in the film top layers and a gradual pore size increase along the film normal in the macroporous sponge-like support structure. Substructure walls between macropores are themselves mesoporous, constituting a structural hierarchy in addition to the pore gradation. Final graded structures can be tailored by tuning casting conditions of self-assembled templates as well as the backfilling processes. We expect that these graded porous inorganic materials may find use in applications including separation, catalysis, biomedical implants, and energy conversion and storage.

Efficient concepts for large erectable space structures

NASA Technical Reports Server (NTRS)

Card, M. F.; Bush, H. G.; Heard, W. L., Jr.; Mikulas, M. M., Jr.

1978-01-01

The status of Langley Research Center development of the nestable column concept is reviewed including results of member and truss component tests, and planned assembly studies. In addition, more recent studies of alternative member concepts are presented. Preliminary results on relative efficiency of several types of truss-type columns are compared and future test plans discussed.

Theory of Connectivity: Nature and Nurture of Cell Assemblies and Cognitive Computation.

PubMed

Li, Meng; Liu, Jun; Tsien, Joe Z

2016-01-01

Richard Semon and Donald Hebb are among the firsts to put forth the notion of cell assembly-a group of coherently or sequentially-activated neurons-to represent percept, memory, or concept. Despite the rekindled interest in this century-old idea, the concept of cell assembly still remains ill-defined and its operational principle is poorly understood. What is the size of a cell assembly? How should a cell assembly be organized? What is the computational logic underlying Hebbian cell assemblies? How might Nature vs. Nurture interact at the level of a cell assembly? In contrast to the widely assumed randomness within the mature but naïve cell assembly, the Theory of Connectivity postulates that the brain consists of the developmentally pre-programmed cell assemblies known as the functional connectivity motif (FCM). Principal cells within such FCM is organized by the power-of-two-based mathematical principle that guides the construction of specific-to-general combinatorial connectivity patterns in neuronal circuits, giving rise to a full range of specific features, various relational patterns, and generalized knowledge. This pre-configured canonical computation is predicted to be evolutionarily conserved across many circuits, ranging from these encoding memory engrams and imagination to decision-making and motor control. Although the power-of-two-based wiring and computational logic places a mathematical boundary on an individual's cognitive capacity, the fullest intellectual potential can be brought about by optimized nature and nurture. This theory may also open up a new avenue to examining how genetic mutations and various drugs might impair or improve the computational logic of brain circuits.

Tuning the reactivity of Al/Fe{sub 2}O{sub 3} nanoenergetic materials via an approach combining soft template self-assembly with sol–gel process process

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

Zhang, Tianfu; Wang, Zhen; Li, Guoping

2015-10-15

A bottom-up approach combining soft template self-assembly with sol–gel process, was adopted to prepare the assembled Al/Fe{sub 2}O{sub 3} nanoenergetic materials, assembly-Al/Fe{sub 2}O{sub 3} sample. The other two unassembled Al/Fe{sub 2}O{sub 3}a nanoenergetic materials, sol–gel–Al/Fe{sub 2}O{sub 3} sample and mixing-Al/Fe{sub 2}O{sub 3} sample, were prepared by sol–gel method and physical mixing method respectively. The assembly process within the preparation of the assembly-Al/Fe{sub 2}O{sub 3} sample was analyzed through the changes in the average hydrodynamic diameters of the particles and the micelles in solution. SEM, EDS and TEM tests were performed to demonstrate a significant improvement regarding to dispersity and arrangementsmore » of the Al and Fe{sub 2}O{sub 3} particles in the assembled samples, compared to that of the unassembled Al/Fe{sub 2}O{sub 3} samples. DSC test was employed to characterize the reactivity of the samples. The heat release of the assembled Al/Fe{sub 2}O{sub 3} sample was 2088 J/g, about 400 and 990 J/g more than that of the sol–gel–Al/Fe{sub 2}O{sub 3} sample and mixing-Al/Fe{sub 2}O{sub 3} sample, respectively. - Graphical abstract: Modified aluminum (Al) nanoparticles with hydrophobic surface assembled into the Brij S10 micelle in Fe(III) sol, then the well dispersed system was transformed into Al/Fe{sub 2}O{sub 3} nanoenergetic materials with high reactivity. - Highlights: • An approach combining soft template self-assembly with sol–gel process was adopted. • The aggregation of Al nanoparticles in the final product was reduced significantly. • The reactivity of Al/Fe{sub 2}O{sub 3} nanoenergetic materials was improved to a large extent.« less

Radiation Chemistry in Organized Assemblies.

ERIC Educational Resources Information Center

Thomas, J. K.; Chen, T. S.

1981-01-01

Expands the basic concepts regarding the radiation chemistry of simple aqueous systems to more complex, but well defined, organized assemblies. Discusses the differences in behavior in comparison to simple systems. Reviews these techniques: pulse radiolysis, laser flash, photolysis, and steady state irradiation by gamma rays or light. (CS)

27 CFR 555.221 - Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in...

Code of Federal Regulations, 2011 CFR

2011-04-01

... fireworks, pyrotechnic compositions, and explosive materials used in assembling fireworks or articles pyrotechnic. 555.221 Section 555.221 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO... Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in assembling...

27 CFR 555.221 - Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in...

Code of Federal Regulations, 2010 CFR

2010-04-01

... fireworks, pyrotechnic compositions, and explosive materials used in assembling fireworks or articles pyrotechnic. 555.221 Section 555.221 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO... Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in assembling...

Biologically inspired dynamic material systems.

PubMed

Studart, André R

2015-03-09

Numerous examples of material systems that dynamically interact with and adapt to the surrounding environment are found in nature, from hair-based mechanoreceptors in animals to self-shaping seed dispersal units in plants to remodeling bone in vertebrates. Inspired by such fascinating biological structures, a wide range of synthetic material systems have been created to replicate the design concepts of dynamic natural architectures. Examples of biological structures and their man-made counterparts are herein revisited to illustrate how dynamic and adaptive responses emerge from the intimate microscale combination of building blocks with intrinsic nanoscale properties. By using top-down photolithographic methods and bottom-up assembly approaches, biologically inspired dynamic material systems have been created 1) to sense liquid flow with hair-inspired microelectromechanical systems, 2) to autonomously change shape by utilizing plantlike heterogeneous architectures, 3) to homeostatically influence the surrounding environment through self-regulating adaptive surfaces, and 4) to spatially concentrate chemical species by using synthetic microcompartments. The ever-increasing complexity and remarkable functionalities of such synthetic systems offer an encouraging perspective to the rich set of dynamic and adaptive properties that can potentially be implemented in future man-made material systems. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Laser-assisted advanced assembly for MEMS fabrication

NASA Astrophysics Data System (ADS)

Atanasov, Yuriy Andreev

Micro Electro-Mechanical Systems (MEMS) are currently fabricated using methods originally designed for manufacturing semiconductor devices, using minimum if any assembly at all. The inherited limitations of this approach narrow the materials that can be employed and reduce the design complexity, imposing limitations on MEMS functionality. The proposed Laser-Assisted Advanced Assembly (LA3) method solves these problems by first fabricating components followed by assembly of a MEMS device. Components are micro-machined using a laser or by photolithography followed by wet/dry etching out of any material available in a thin sheet form. A wide range of materials can be utilized, including biocompatible metals, ceramics, polymers, composites, semiconductors, and materials with special properties such as memory shape alloys, thermoelectric, ferromagnetic, piezoelectric, and more. The approach proposed allows enhancing the structural and mechanical properties of the starting materials through heat treatment, tribological coatings, surface modifications, bio-functionalization, and more, a limited, even unavailable possibility with existing methods. Components are transferred to the substrate for assembly using the thermo-mechanical Selective Laser Assisted Die Transfer (tmSLADT) mechanism for microchips assembly, already demonstrated by our team. Therefore, the mechanical and electronic part of the MEMS can be fabricated using the same equipment/method. The viability of the Laser-Assisted Advanced Assembly technique for MEMS is demonstrated by fabricating magnetic switches for embedding in a conductive carbon-fiber metamaterial for use in an Electromagnetic-Responsive Mobile Cyber-Physical System (E-RMCPS), which is expected to improve the wireless communication system efficiency within a battery-powered device.

The Quest for Community in a National Republic: A Bicentennial Reappraisal. Final Report and Keynote Address, Virginia Assembly (Richmond, Virginia, April 8-10, 1988).

ERIC Educational Resources Information Center

Virginia Univ., Charlottesville. Center for Public Service.

This Virginia Assembly document focuses on the concept of community as defined by the Founding Fathers of the U.S. Constitution. The final report identifies and discusses problems related to the modern quest for community in a national republic. Recommendations by the Assembly are offered in eight areas: (1) civic responsibility; (2) corporate…

Assembly considerations for large reflectors

NASA Technical Reports Server (NTRS)

Bush, H.

1988-01-01

The technologies developed at LaRC in the area of erectable instructures are discussed. The information is of direct value to the Large Deployable Reflector (LDR) because an option for the LDR backup structure is to assemble it in space. The efforts in this area, which include development of joints, underwater assembly simulation tests, flight assembly/disassembly tests, and fabrication of 5-meter trusses, led to the use of the LaRC concept as the baseline configuration for the Space Station Structure. The Space Station joint is linear in the load and displacement range of interest to Space Station; the ability to manually assemble and disassemble a 45-foot truss structure was demonstrated by astronauts in space as part of the ACCESS Shuttle Flight Experiment. The structure was built in 26 minutes 46 seconds, and involved a total of 500 manipulations of untethered hardware. Also, the correlation of the space experience with the neutral buoyancy simulation was very good. Sections of the proposed 5-meter bay Space Station truss have been built on the ground. Activities at LaRC have included the development of mobile remote manipulator systems (which can traverse the Space Station 5-meter structure), preliminary LDR sun shield concepts, LDR construction scenarios, and activities in robotic assembly of truss-type structures.

A Robust and Engineerable Self-Assembling Protein Template for the Synthesis and Patterning of Ordered Nanoparticle Arrays

NASA Technical Reports Server (NTRS)

McMillan, R. Andrew; Howard, Jeanie; Zaluzec, Nestor J.; Kagawa, Hiromi K.; Li, Yi-Fen; Paavola, Chad D.; Trent, Jonathan D.

2004-01-01

Self-assembling biomolecules that form highly ordered structures have attracted interest as potential alternatives to conventional lithographic processes for patterning materials. Here we introduce a general technique for patterning materials on the nanoscale using genetically modified protein cage structures called chaperonins that self-assemble into crystalline templates. Constrained chemical synthesis of transition metal nanoparticles is specific to templates genetically functionalized with poly-Histidine sequences. These arrays of materials are ordered by the nanoscale structure of the crystallized protein. This system may be easily adapted to pattern a variety of materials given the rapidly growing list of peptide sequences selected by screening for specificity for inorganic materials.

Miniature cryocooler developments for high operating temperatures at Thales Cryogenics

NASA Astrophysics Data System (ADS)

Arts, R.; Martin, J.-Y.; Willems, D.; Seguineau, C.; Van Acker, S.; Mullié, J. C.; Göbel, A.; Tops, M.; Le Bordays, J.; Etchanchu, T.; Benschop, A. A. J.

2015-05-01

In recent years there has been a drive towards miniaturized cooled IDCA solutions for low-power, low-mass, low-size products (SWaP). To support this drive, coolers are developed optimized for high-temperature, low heat load dewar-detector assemblies. In this paper, Thales Cryogenics development activities supporting SWaP are presented. Design choices are discussed and compared to various key requirements. Trade-off analysis results are presented on drive voltage, cold finger definition (length, material, diameter and sealing concept), and other interface considerations, including cold finger definition. In parallel with linear and rotary cooler options, designs for small-size high-efficiency drive electronics based on state-of-the-art architectures are presented.

On the application potential of gold nanoparticles in nanoelectronics and biomedicine.

PubMed

Homberger, Melanie; Simon, Ulrich

2010-03-28

Ligand-stabilized gold nanoparticles (AuNPs) are of high interest to research dedicated to future technologies such as nanoelectronics or biomedical applications. This research interest arises from the unique size-dependent properties such as surface plasmon resonance or Coulomb charging effects. It is shown here how the unique properties of individual AuNPs and AuNP assemblies can be used to create new functional materials for applications in a technical or biological environment. While the term technical environment focuses on the potential use of AuNPs as subunits in nanoelectronic devices, the term biological environment addresses issues of toxicity and novel concepts of controlling biomolecular reactions on the surface of AuNPs.

Ordered patterns and structures via interfacial self-assembly: superlattices, honeycomb structures and coffee rings.

PubMed

Ma, Hongmin; Hao, Jingcheng

2011-11-01

Self-assembly is now being intensively studied in chemistry, physics, biology, and materials engineering and has become an important "bottom-up" approach to create intriguing structures for different applications. Self-assembly is not only a practical approach for creating a variety of nanostructures, but also shows great superiority in building hierarchical structures with orders on different length scales. The early work in self-assembly focused on molecular self-assembly in bulk solution, including the resultant dye aggregates, liposomes, vesicles, liquid crystals, gels and so on. Interfacial self-assembly has been a great concern over the last two decades, largely because of the unique and ingenious roles of this method for constructing materials at interfaces, such as self-assembled monolayers, Langmuir-Blodgett films, and capsules. Nanocrystal superlattices, honeycomb films and coffee rings are intriguing structural materials with more complex features and can be prepared by interfacial self-assembly on different length scales. In this critical review, we outline the recent development in the preparation and application of colloidal nanocrystal superlattices, honeycomb-patterned macroporous structures by the breath figure method, and coffee-ring-like patterns (247 references). This journal is © The Royal Society of Chemistry 2011

Evaluation of beryllium for space shuttle components

NASA Technical Reports Server (NTRS)

Trapp, A. E.

1972-01-01

Application of beryllium to specific full-scale space shuttle structural components and assemblies was studied. Material evaluations were conducted to check the mechanical properties of as-received material to gain design information on characteristics needed for the material in the space shuttle environment, and to obtain data needed for evaluating component and panel tests. Four beryllium structural assemblies were analyzed and designed. Selected components of these assemblies, representing areas of critical loading or design/process uncertainty, were designed and tested, and two panel assemblies were fabricated. Trends in cost and weight factors were determined by progressive estimation at key points of preliminary design, final design, and fabrication to aid in a cost/weight evaluation of the use of beryllium.

Paradigm shift from self-assembly to commanded assembly of functional materials: recent examples in porphyrin/fullerene supramolecular systems

NASA Astrophysics Data System (ADS)

Li, Mao; Ishihara, Shinsuke; Ji, Qingmin; Akada, Misaho; Hill, Jonathan P.; Ariga, Katsuhiko

2012-10-01

Current nanotechnology based on top-down nanofabrication may encounter a variety of drawbacks in the near future so that development of alternative methods, including the so-called bottom-up approach, has attracted considerable attention. However, the bottom-up strategy, which often relies on spontaneous self-assembly, might be inefficient in the development of the requisite functional materials and systems. Therefore, assembly processes controlled by external stimuli might be a plausible strategy for the development of bottom-up nanotechnology. In this review, we demonstrate a paradigm shift from self-assembly to commanded assembly by describing several examples of assemblies of typical functional molecules, i.e. porphyrins and fullerenes. In the first section, we describe recent progress in the design and study of self-assembled and co-assembled supramolecular architectures of porphyrins and fullerenes. Then, we show examples of assembly induced by external stimuli. We emphasize the paradigm shift from self-assembly to commanded assembly by describing the recently developed electrochemical-coupling layer-by-layer (ECC-LbL) methodology.

Aggregate nanostructures of organic molecular materials.

PubMed

Liu, Huibiao; Xu, Jialiang; Li, Yongjun; Li, Yuliang

2010-12-21

Conjugated organic molecules are interesting materials because of their structures and their electronic, electrical, magnetic, optical, biological, and chemical properties. However, researchers continue to face great challenges in the construction of well-defined organic compounds that aggregate into larger molecular materials such as nanowires, tubes, rods, particles, walls, films, and other structural arrays. Such nanoscale materials could serve as direct device components. In this Account, we describe our recent progress in the construction of nanostructures formed through the aggregation of organic conjugated molecules and in the investigation of the optical, electrical, and electronic properties that depend on the size or morphology of these nanostructures. We have designed and synthesized functional conjugated organic molecules with structural features that favor assembly into aggregate nanostructures via weak intermolecular interactions. These large-area ordered molecular aggregate nanostructures are based on a variety of simpler structures such as fullerenes, perylenes, anthracenes, porphyrins, polydiacetylenes, and their derivatives. We have developed new methods to construct these larger structures including organic vapor-solid phase reaction, natural growth, association via self-polymerization and self-organization, and a combination of self-assembly and electrochemical growth. These methods are both facile and reliable, allowing us to produce ordered and aligned aggregate nanostructures, such as large-area arrays of nanowires, nanorods, and nanotubes. In addition, we can synthesize nanoscale materials with controlled properties. Large-area ordered aggregate nanostructures exhibit interesting electrical, optical, and optoelectronic properties. We also describe the preparation of large-area aggregate nanostructures of charge transfer (CT) complexes using an organic solid-phase reaction technique. By this process, we can finely control the morphologies and sizes of the organic nanostructures on wires, tubes, and rods. Through field emission studies, we demonstrate that the films made from arrays of CT complexes are a new kind of cathode materials, and we systematically investigate the effects of size and morphology on electrical properties. Low-dimension organic/inorganic hybrid nanostructures can be used to produce new classes of organic/inorganic solid materials with properties that are not observed in either the individual nanosize components or the larger bulk materials. We developed the combined self-assembly and templating technique to construct various nanostructured arrays of organic and inorganic semiconductors. The combination of hybrid aggregate nanostructures displays distinct optical and electrical properties compared with their individual components. Such hybrid structures show promise for applications in electronics, optics, photovoltaic cells, and biology. In this Account, we aim to provide an intuition for understanding the structure-function relationships in organic molecular materials. Such principles could lead to new design concepts for the development of new nonhazardous, high-performance molecular materials on aggregate nanostructures.

Fuel cell with electrolyte matrix assembly

DOEpatents

Kaufman, Arthur; Pudick, Sheldon; Wang, Chiu L.

1988-01-01

This invention is directed to a fuel cell employing a substantially immobilized electrolyte imbedded therein and having a laminated matrix assembly disposed between the electrodes of the cell for holding and distributing the electrolyte. The matrix assembly comprises a non-conducting fibrous material such as silicon carbide whiskers having a relatively large void-fraction and a layer of material having a relatively small void-fraction.

Tuning the entropic spring to dictate order and functionality in polymer conjugated peptide biomaterials

NASA Astrophysics Data System (ADS)

Keten, Sinan

Hybrid peptide-polymer conjugates have the potential to combine the advantages of natural proteins and synthetic polymers, resulting in biomaterials with improved stability, controlled assembly, and tailored functionalities. However, the effect of polymer conjugation on peptide structural organization and functionality, along with the behavior of polymers at the interface with biomolecules remain to be fully understood. This talk will summarize our recent efforts towards establishing a modeling framework to design entropic forces in helix-polymer conjugates and polymer-conjugated peptide nanotubes to achieve hierarchical self-assembling systems with predictable order. The first part of the talk will discuss how self-assembly principles found in biology, combined with polymer physics concepts can be used to create artificial membranes that mimic certain features of ion channels. Thermodynamics and kinetics aspects of self-assembly and how it governs the growth and stacking sequences of peptide nanotubes will be discussed, along with its implications for nanoscale transport. The second part of the talk will review advances related to modeling polymer conjugated coiled coils at relevant length and time scales. Atomistic simulations combined with sampling techniques will be presented to discuss the energy landscapes governing coiled-coil stability, revealing cascades of events governing disassembly. This will be followed by a discussion of mechanisms through which polymers can stabilize small proteins, such as shielding of solvents, and how specific peptide sequences can reciprocate by altering polymer conformations. Correlations between mechanical and thermal stability of peptides will be discussed. Finally, coarse-grained simulations will provide insight into how the location of polymer attachment changes entropic forces and higher-level organization in helix bundle assemblies. Our findings set the stage for a materials-by-design capability towards dictating complex topologies of polymer-peptide conjugate systems.

Definition of large components assembled on-orbit and robot compatible mechanical joints

NASA Technical Reports Server (NTRS)

Williamsen, J.; Thomas, F.; Finckenor, J.; Spiegel, B.

1990-01-01

One of four major areas of project Pathfinder is in-space assembly and construction. The task of in-space assembly and construction is to develop the requirements and the technology needed to build elements in space. A 120-ft diameter tetrahedral aerobrake truss is identified as the focus element. A heavily loaded mechanical joint is designed to robotically assemble the defined aerobrake element. Also, typical large components such as habitation modules, storage tanks, etc., are defined, and attachment concepts of these components to the tetrahedral truss are developed.

Swell Gels to Dumbbell Micelles: Construction of Materials and Nanostructure with Self-assembly

NASA Astrophysics Data System (ADS)

Pochan, Darrin

2007-03-01

Bionanotechnology, the emerging field of using biomolecular and biotechnological tools for nanostructure or nanotecnology development, provides exceptional opportunity in the design of new materials. Self-assembly of molecules is an attractive materials construction strategy due to its simplicity in application. By considering peptidic or charged synthetic polymer molecules in the bottom-up materials self-assembly design process, one can take advantage of inherently biomolecular attributes; intramolecular folding events, secondary structure, and electrostatic interactions; in addition to more traditional self-assembling molecular attributes such as amphiphilicty, to define hierarchical material structure and consequent properties. Several molecular systems will be discussed. Synthetic block copolymers with charged corona blocks can be assembled in dilute solution containing multivalent organic counterions to produce micelle structures such as toroids. These ring-like micelles are similar to the toroidal bundling of charged semiflexible biopolymers like DNA in the presence of multivalent counterions. Micelle structure can be tuned between toroids, cylinders, and disks simply by using different concentrations or molecular volumes of organic counterion. In addition, these charged blocks can consist of amino acids as monomers producing block copolypeptides. In addition to the above attributes, block copolypeptides provide the control of block secondary structure to further control self-assembly. Design strategies based on small (less than 24 amino acids) beta-hairpin peptides will be discussed. Self-assembly of the peptides is predicated on an intramolecular folding event caused by desired solution properties. Importantly, the intramolecular folding event impart a molecular-level mechanism for environmental responsiveness at the material level (e.g. infinite change in viscosity of a solution to a gel with changes in pH, ionic strength, temperature).

Dynamic and programmable self-assembly of micro-rafts at the air-water interface

PubMed Central

Wang, Wendong; Giltinan, Joshua; Zakharchenko, Svetlana; Sitti, Metin

2017-01-01

Dynamic self-assembled material systems constantly consume energy to maintain their spatiotemporal structures and functions. Programmable self-assembly translates information from individual parts to the collective whole. Combining dynamic and programmable self-assembly in a single platform opens up the possibilities to investigate both types of self-assembly simultaneously and to explore their synergy. This task is challenging because of the difficulty in finding suitable interactions that are both dissipative and programmable. We present a dynamic and programmable self-assembling material system consisting of spinning at the air-water interface circular magnetic micro-rafts of radius 50 μm and with cosinusoidal edge-height profiles. The cosinusoidal edge-height profiles not only create a net dissipative capillary repulsion that is sustained by continuous torque input but also enable directional assembly of micro-rafts. We uncover the layered arrangement of micro-rafts in the patterns formed by dynamic self-assembly and offer mechanistic insights through a physical model and geometric analysis. Furthermore, we demonstrate programmable self-assembly and show that a 4-fold rotational symmetry encoded in individual micro-rafts translates into 90° bending angles and square-based tiling in the assembled structures of micro-rafts. We anticipate that our dynamic and programmable material system will serve as a model system for studying nonequilibrium dynamics and statistical mechanics in the future. PMID:28560332

Dynamic and programmable self-assembly of micro-rafts at the air-water interface.

PubMed

Wang, Wendong; Giltinan, Joshua; Zakharchenko, Svetlana; Sitti, Metin

2017-05-01

Dynamic self-assembled material systems constantly consume energy to maintain their spatiotemporal structures and functions. Programmable self-assembly translates information from individual parts to the collective whole. Combining dynamic and programmable self-assembly in a single platform opens up the possibilities to investigate both types of self-assembly simultaneously and to explore their synergy. This task is challenging because of the difficulty in finding suitable interactions that are both dissipative and programmable. We present a dynamic and programmable self-assembling material system consisting of spinning at the air-water interface circular magnetic micro-rafts of radius 50 μm and with cosinusoidal edge-height profiles. The cosinusoidal edge-height profiles not only create a net dissipative capillary repulsion that is sustained by continuous torque input but also enable directional assembly of micro-rafts. We uncover the layered arrangement of micro-rafts in the patterns formed by dynamic self-assembly and offer mechanistic insights through a physical model and geometric analysis. Furthermore, we demonstrate programmable self-assembly and show that a 4-fold rotational symmetry encoded in individual micro-rafts translates into 90° bending angles and square-based tiling in the assembled structures of micro-rafts. We anticipate that our dynamic and programmable material system will serve as a model system for studying nonequilibrium dynamics and statistical mechanics in the future.

Category Theoretic Analysis of Hierarchical Protein Materials and Social Networks

PubMed Central

Spivak, David I.; Giesa, Tristan; Wood, Elizabeth; Buehler, Markus J.

2011-01-01

Materials in biology span all the scales from Angstroms to meters and typically consist of complex hierarchical assemblies of simple building blocks. Here we describe an application of category theory to describe structural and resulting functional properties of biological protein materials by developing so-called ologs. An olog is like a “concept web” or “semantic network” except that it follows a rigorous mathematical formulation based on category theory. This key difference ensures that an olog is unambiguous, highly adaptable to evolution and change, and suitable for sharing concepts with other olog. We consider simple cases of beta-helical and amyloid-like protein filaments subjected to axial extension and develop an olog representation of their structural and resulting mechanical properties. We also construct a representation of a social network in which people send text-messages to their nearest neighbors and act as a team to perform a task. We show that the olog for the protein and the olog for the social network feature identical category-theoretic representations, and we proceed to precisely explicate the analogy or isomorphism between them. The examples presented here demonstrate that the intrinsic nature of a complex system, which in particular includes a precise relationship between structure and function at different hierarchical levels, can be effectively represented by an olog. This, in turn, allows for comparative studies between disparate materials or fields of application, and results in novel approaches to derive functionality in the design of de novo hierarchical systems. We discuss opportunities and challenges associated with the description of complex biological materials by using ologs as a powerful tool for analysis and design in the context of materiomics, and we present the potential impact of this approach for engineering, life sciences, and medicine. PMID:21931622

End-effector: Joint conjugates for robotic assembly of large truss structures in space: Extended concepts

NASA Technical Reports Server (NTRS)

Brewer, W. V.; Rasis, E. P.; Shih, H. R.

1993-01-01

Results from NASA/HBCU Grant No. NAG-1-1125 are summarized. Designs developed for model fabrication, exploratory concepts drafted, interface of computer with robot and end-effector, and capability enhancement are discussed.

Toward a modular multi-material nanoparticle synthesis and assembly strategy via bionanocombinatorics: bifunctional peptides for linking Au and Ag nanomaterials

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

Briggs, Beverly D.; Palafox-Hernandez, J. Pablo; Li, Yue

Materials-binding peptides represent a unique avenue towards controlling the shape and size of nanoparticles (NPs) grown under aqueous conditions. Here, employing a bionanocombinatorics approach, two such materials-binding peptides were linked at either end of a photoswitchable spacer, forming a multi-domain materials-binding molecule to control the in situ synthesis and organization of Ag and Au NPs under ambient conditions. These multi-domain molecules retained the peptides’ ability to nucleate, grow, and stabilize Ag and Au NPs in aqueous media. Disordered co-assemblies of the two nanomaterials were observed by TEM imaging of dried samples after sequential growth of the two metals, and showedmore » a clustering behavior that was not observed without both metals and the linker molecules. While TEM evidence indicated the formation of AuNP/AgNP assemblies upon drying, SAXS analysis indicated that no extended assemblies existed in solution, suggesting that sample drying plays an important role in facilitating NP clustering. Molecular simulations and experimental data revealed tunable materials-binding based upon the isomerization state of the photoswitchable unit and metal employed. This work is a first step in generating externally actuated biomolecules with specific material-binding properties that could be used as the building blocks to achieve multi-material switchable NP assemblies.« less

Cooperativity governs the size and structure of biological interfaces.

PubMed

Qin, Zhao; Buehler, Markus J

2012-11-15

Interfaces, defined as the surface of interactions between two parts of a system at a discontinuity, are very widely found in nature. While it is known that the specific structure of an interface plays an important role in defining its properties, it is less clear whether or not there exist universal scaling laws that govern the structural evolution of a very broad range of natural interfaces. Here we show that cooperativity of interacting elements, leading to great strength at low material use, is a key concept that governs the structural evolution of many natural interfaces. We demonstrate this concept for the cases of β-sheet proteins in spider silk, gecko feet, legs of caterpillars, and self-assembling of penguins into huddles, which range in scales from the submolecular to the macroscopic level. A general model is proposed that explains the size and structure of biological interfaces from a fundamental point of view. Copyright © 2012 Elsevier Ltd. All rights reserved.

Heat Treating Apparatus

DOEpatents

De Saro, Robert; Bateman, Willis

2002-09-10

Apparatus for heat treating a heat treatable material including a housing having an upper opening for receiving a heat treatable material at a first temperature, a lower opening, and a chamber therebetween for heating the heat treatable material to a second temperature higher than the first temperature as the heat treatable material moves through the chamber from the upper to the lower opening. A gas supply assembly is operatively engaged to the housing at the lower opening, and includes a source of gas, a gas delivery assembly for delivering the gas through a plurality of pathways into the housing in countercurrent flow to movement of the heat treatable material, whereby the heat treatable material passes through the lower opening at the second temperature, and a control assembly for controlling conditions within the chamber to enable the heat treatable material to reach the second temperature and pass through the lower opening at the second temperature as a heated material.

The mechanics and design of a lightweight three-dimensional graphene assembly

PubMed Central

Qin, Zhao; Jung, Gang Seob; Kang, Min Jeong; Buehler, Markus J.

2017-01-01

Recent advances in three-dimensional (3D) graphene assembly have shown how we can make solid porous materials that are lighter than air. It is plausible that these solid materials can be mechanically strong enough for applications under extreme conditions, such as being a substitute for helium in filling up an unpowered flight balloon. However, knowledge of the elastic modulus and strength of the porous graphene assembly as functions of its structure has not been available, preventing evaluation of its feasibility. We combine bottom-up computational modeling with experiments based on 3D-printed models to investigate the mechanics of porous 3D graphene materials, resulting in new designs of carbon materials. Our study reveals that although the 3D graphene assembly has an exceptionally high strength at relatively high density (given the fact that it has a density of 4.6% that of mild steel and is 10 times as strong as mild steel), its mechanical properties decrease with density much faster than those of polymer foams. Our results provide critical densities below which the 3D graphene assembly starts to lose its mechanical advantage over most polymeric cellular materials. PMID:28070559

STS-61B Astronauts Ross and Spring Work on Experimental Assembly of Structures in Extravehicular

NASA Technical Reports Server (NTRS)

1985-01-01

The crew assigned to the STS-61B mission included Bryan D. O'Conner, pilot; Brewster H. Shaw, commander; Charles D. Walker, payload specialist; mission specialists Jerry L. Ross, Mary L. Cleave, and Sherwood C. Spring; and Rodolpho Neri Vela, payload specialist. Launched aboard the Space Shuttle Atlantis November 28, 1985 at 7:29:00 pm (EST), the STS-61B mission's primary payload included three communications satellites: MORELOS-B (Mexico); AUSSAT-2 (Australia); and SATCOM KU-2 (RCA Americom). Two experiments were conducted to test assembling erectable structures in space: EASE (Experimental Assembly of Structures in Extravehicular Activity), and ACCESS (Assembly Concept for Construction of Erectable Space Structure). In a joint venture between NASA/Langley Research Center in Hampton, Virginia, and the Marshall Space Flight Center (MSFC), EASE and ACCESS were developed and demonstrated at MSFC's Neutral Buoyancy Simulator (NBS). This STS-61B onboard photo depicts astronauts Ross and Spring working on EASE. The primary objective of these experiments was to test the structural assembly concepts for suitability as the framework for larger space structures and to identify ways to improve the productivity of space construction.

Relations between Young Students' Strategic Behaviours, Domain-Specific Self-Concept, and Performance in a Problem-Solving Situation

ERIC Educational Resources Information Center

Dermitzaki, Irini; Leondari, Angeliki; Goudas, Marios

2009-01-01

This study aimed at investigating the relations between students' strategic behaviour during problem solving, task performance and domain-specific self-concept. A total of 167 first- and second-graders were individually examined in tasks involving cubes assembly and in academic self-concept in mathematics. Students' cognitive, metacognitive, and…

The development and testing of the thermal break divertor monoblock target design delivering 20 MW m-2 heat load capability

NASA Astrophysics Data System (ADS)

Fursdon, M.; Barrett, T.; Domptail, F.; Evans, Ll M.; Luzginova, N.; Greuner, N. H.; You, J.-H.; Li, M.; Richou, M.; Gallay, F.; Visca, E.

2017-12-01

The design and development of a novel plasma facing component (for fusion power plants) is described. The component uses the existing ‘monoblock’ construction which consists of a tungsten ‘block’ joined via a copper interlayer to a through CuCrZr cooling pipe. In the new concept the interlayer stiffness and conductivity properties are tuned so that stress in the principal structural element of the component (the cooling pipe) is reduced. Following initial trials with off-the-shelf materials, the concept was realized by machined features in an otherwise solid copper interlayer. The shape and distribution of the features were tuned by finite element analyses subject to ITER structural design criterion in-vessel components (SDC-IC) design rules. Proof of concept mock-ups were manufactured using a two stage brazing process verified by tomography and micrographic inspection. Full assemblies were inspected using ultrasound and thermographic (SATIR) test methods at ENEA and CEA respectively. High heat flux tests using IPP’s GLADIS facility showed that 200 cycles at 20 MW m-2 and five cycles at 25 MW m-2 could be sustained without apparent component damage. Further testing and component development is planned.

Digital Material Assembly by Passive Means and Modular Isotropic Lattice Extruder System

NASA Technical Reports Server (NTRS)

Gershenfeld, Neil (Inventor); Carney, Matthew Eli (Inventor); Jenett, Benjamin (Inventor)

2017-01-01

A set of machines and related systems build structures by the additive assembly of discrete parts. These digital material assemblies constrain the constituent parts to a discrete set of possible positions and orientations. In doing so, the structures exhibit many of the properties inherent in digital communication such as error correction, fault tolerance and allow the assembly of precise structures with comparatively imprecise tools. Assembly of discrete cellular lattices by a Modular Isotropic Lattice Extruder System (MILES) is implemented by pulling strings of lattice elements through a forming die that enforces geometry constraints that lock the elements into a rigid structure that can then be pushed against and extruded out of the die as an assembled, loadbearing structure.

Advanced composite applications for sub-micron biologically derived microstructures

NASA Technical Reports Server (NTRS)

Schnur, J. M.; Price, R. R.; Schoen, P. E.; Bonanventura, Joseph; Kirkpatrick, Douglas

1991-01-01

A major thrust of advanced material development is in the area of self-assembled ultra-fine particulate based composites (micro-composites). The application of biologically derived, self-assembled microstructures to form advanced composite materials is discussed. Hollow 0.5 micron diameter cylindrical shaped microcylinders self-assemble from diacetylenic lipids. These microstructures have a multiplicity of potential applications in the material sciences. Exploratory development is proceeding in application areas such as controlled release for drug delivery, wound repair, and biofouling as well as composites for electronic and magnetic applications, and high power microwave cathodes.

Multi-wavelength mid-IR light source for gas sensing

NASA Astrophysics Data System (ADS)

Karioja, Pentti; Alajoki, Teemu; Cherchi, Matteo; Ollila, Jyrki; Harjanne, Mikko; Heinilehto, Noora; Suomalainen, Soile; Viheriälä, Jukka; Zia, Nouman; Guina, Mircea; Buczyński, Ryszard; Kasztelanic, Rafał; Kujawa, Ireneusz; Salo, Tomi; Virtanen, Sami; Kluczyński, Paweł; Sagberg, Hâkon; Ratajczyk, Marcin; Kalinowski, Przemyslaw

2017-02-01

Cost effective multi-wavelength light sources are key enablers for wide-scale penetration of gas sensors at Mid-IR wavelength range. Utilizing novel Mid-IR Si-based photonic integrated circuits (PICs) filter and wide-band Mid-IR Super Luminescent Light Emitting Diodes (SLEDs), we show the concept of a light source that covers 2.5…3.5 μm wavelength range with a resolution of <1nm. The spectral bands are switchable and tunable and they can be modulated. The source allows for the fabrication of an affordable multi-band gas sensor with good selectivity and sensitivity. The unit price can be lowered in high volumes by utilizing tailored molded IR lens technology and automated packaging and assembling technologies. The status of the development of the key components of the light source are reported. The PIC is based on the use of micron-scale SOI technology, SLED is based on AlGaInAsSb materials and the lenses are tailored heavy metal oxide glasses fabricated by the use of hot-embossing. The packaging concept utilizing automated assembly tools is depicted. In safety and security applications, the Mid-IR wavelength range covered by the novel light source allows for detecting several harmful gas components with a single sensor. At the moment, affordable sources are not available. The market impact is expected to be disruptive, since the devices currently in the market are either complicated, expensive and heavy instruments, or the applied measurement principles are inadequate in terms of stability and selectivity.

Cross-stiffened continuous fiber structures

NASA Technical Reports Server (NTRS)

Ewen, John R.; Suarez, Jim A.

1993-01-01

Under NASA's Novel Composites for Wing and Fuselage Applications (NCWFA) program, Contract NAS1-18784, Grumman is evaluating the structural efficiency of graphite/epoxy cross-stiffened panel elements fabricated using innovative textile preforms and cost effective Resin Transfer Molding (RTM) and Resin Film Infusion (RFI) processes. Two three-dimensional woven preform assembly concepts have been defined for application to a representative window belt design typically found in a commercial transport airframe. The 3D woven architecture for each of these concepts is different; one is vertically woven in the plane of the window belt geometry and the other is loom woven in a compressed state similar to an unfolded eggcrate. The feasibility of both designs has been demonstrated in the fabrication of small test element assemblies. These elements and the final window belt assemblies will be structurally tested, and results compared.

Photoinitated charge separation in a hybrid titanium dioxide metalloporphyrin peptide material

NASA Astrophysics Data System (ADS)

Fry, H. Christopher; Liu, Yuzi; Dimitrijevic, Nada M.; Rajh, Tijana

2014-08-01

In natural systems, electron flow is mediated by proteins that spatially organize donor and acceptor molecules with great precision. Achieving this guided, directional flow of information is a desirable feature in photovoltaic media. Here, we design self-assembled peptide materials that organize multiple electronic components capable of performing photoinduced charge separation. Two peptides, c16-AHL3K3-CO2H and c16-AHL3K9-CO2H, self-assemble into fibres and provide a scaffold capable of binding a metalloporphyrin via histidine axial ligation and mineralize titanium dioxide (TiO2) on the lysine-rich surface of the resulting fibrous structures. Electron paramagnetic resonance studies of this self-assembled material under continuous light excitation demonstrate charge separation induced by excitation of the metalloporphyrin and mediated by the peptide assembly structure. This approach to dye-sensitized semiconducting materials offers a means to spatially control the dye molecule with respect to the semiconducting material through careful, strategic peptide design.

Method for sealing an oxygen transport membrane assembly

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

Gonzalez, Javier E.; Grant, Arthur F.

An improved method of sealing a ceramic part to a solid part made of ceramic, metal, cermet or a ceramic coated metal is provided. The improved method includes placing a bond agent comprising an Al 2O 3 and SiO 2 based glass-ceramic material and organic binder material on adjoining surfaces of the ceramic part and the solid part. The assembly is heated to a first target temperature that removes or dissolves the organic binder material from the bond agent and the assembly is subjected to a second induction heating step at a temperature ramp rate of between about 100.degree. C.more » and 200.degree. C. per minute to temperatures where the glass-ceramic material flows and wets the interface between adjoining surfaces. The assembly is rapidly cooled at a cooling rate of about 140.degree. C. per minute or more to induce nucleation and re-crystallization of the glass-ceramic material to form a dense, durable and gas-tight seal.« less

Micro-masonry for 3D additive micromanufacturing.

PubMed

Keum, Hohyun; Kim, Seok

2014-08-01

Transfer printing is a method to transfer solid micro/nanoscale materials (herein called 'inks') from a substrate where they are generated to a different substrate by utilizing elastomeric stamps. Transfer printing enables the integration of heterogeneous materials to fabricate unexampled structures or functional systems that are found in recent advanced devices such as flexible and stretchable solar cells and LED arrays. While transfer printing exhibits unique features in material assembly capability, the use of adhesive layers or the surface modification such as deposition of self-assembled monolayer (SAM) on substrates for enhancing printing processes hinders its wide adaptation in microassembly of microelectromechanical system (MEMS) structures and devices. To overcome this shortcoming, we developed an advanced mode of transfer printing which deterministically assembles individual microscale objects solely through controlling surface contact area without any surface alteration. The absence of an adhesive layer or other modification and the subsequent material bonding processes ensure not only mechanical bonding, but also thermal and electrical connection between assembled materials, which further opens various applications in adaptation in building unusual MEMS devices.

Putting Parameters in Their Proper Place

ERIC Educational Resources Information Center

Montrul, Silvina; Yoon, James

2009-01-01

Seeing the logical problem of second language acquisition as that of primarily selecting and re-assembling bundles of features anew, Lardiere proposes to dispense with the deductive learning approach and its broad range of consequences subsumed under the concept of parameters. While we agree that feature assembly captures more precisely the…

Noncovalent fabrication and tunable fusion of block copolymer-giant polyoxometalate hybrid micelles.

PubMed

Zhang, Liying; Li, Haolong; Wu, Lixin

2014-09-21

The block copolymers (BCs), as structure-directing agents, co-assembling with nanoscale inorganic additives is an important route to fabricate nanostructured hybrid materials. In this work, we present a facile approach to fabricate hybrid micelles composed of BCs and polyoxometalates (POMs), in which the POM clusters are premodified with the groups that can specifically interact with a certain BC block. A representative POM (NH4)42[Mo(132)O(372)(CH(3)COO)(30)(H2O)72] (Mo(132)) is chosen as the example and encapsulated with cationic molecules containing carboxyphenyl groups through electrostatic interactions, and then the resulting hybrid complex can further co-assemble with poly(styrene-block-4-vinylpyridine) (PS-b-P4VP) through hydrogen bonding with the pyridine groups, which leads to the formation of hybrid micelles and the localization of Mo(132) in the micelle cores. The micelles exhibit a high stability despite time and dilution. Furthermore, the fusion of the micelles can be readily adjusted by varying the length of PS blocks, which is promising to be used in constructing polymer-POM hybrid materials with discrete or continuous hybrid domains. This work is based on the electrostatic premodification of POMs and thus its concept is generally suitable for the whole anionic POM system, which may create a large class of BC-POM nanocomposites with tunable structures.

33 CFR 154.500 - Hose assemblies.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Hose assemblies. 154.500 Section... assemblies. Each hose assembly used for transferring oil or hazardous material must meet the following requirements: (a) The minimum design burst pressure for each hose assembly must be at least four times the sum...

33 CFR 154.500 - Hose assemblies.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Hose assemblies. 154.500 Section... assemblies. Each hose assembly used for transferring oil or hazardous material must meet the following requirements: (a) The minimum design burst pressure for each hose assembly must be at least four times the sum...

33 CFR 154.500 - Hose assemblies.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Hose assemblies. 154.500 Section... assemblies. Each hose assembly used for transferring oil or hazardous material must meet the following requirements: (a) The minimum design burst pressure for each hose assembly must be at least four times the sum...

33 CFR 154.500 - Hose assemblies.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Hose assemblies. 154.500 Section... assemblies. Each hose assembly used for transferring oil or hazardous material must meet the following requirements: (a) The minimum design burst pressure for each hose assembly must be at least four times the sum...

33 CFR 154.500 - Hose assemblies.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Hose assemblies. 154.500 Section... assemblies. Each hose assembly used for transferring oil or hazardous material must meet the following requirements: (a) The minimum design burst pressure for each hose assembly must be at least four times the sum...

75 FR 18446 - Airworthiness Directives; The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-12

... assemblies in the ECS with burned Boeing Material Specification (BMS) 8-39 polyurethane foam insulation. This... duct assemblies in the ECS wrapped with BMS 8-39 polyurethane foam insulation, a material of which the... electrical arc from igniting the BMS 8-39 polyurethane foam insulation on the duct assemblies of the ECS...

Microscale assembly directed by liquid-based template.

PubMed

Chen, Pu; Luo, Zhengyuan; Güven, Sinan; Tasoglu, Savas; Ganesan, Adarsh Venkataraman; Weng, Andrew; Demirci, Utkan

2014-09-10

A liquid surface established by standing waves is used as a dynamically reconfigurable template to assemble microscale materials into ordered, symmetric structures in a scalable and parallel manner. The broad applicability of this technology is illustrated by assembling diverse materials from soft matter, rigid bodies, individual cells, cell spheroids and cell-seeded microcarrier beads. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nanopatterned ferroelectrics for ultrahigh density rad-hard nonvolatile memories.

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

Brennecka, Geoffrey L.; Stevens, Jeffrey; Scrymgeour, David

2010-09-01

Radiation hard nonvolatile random access memory (NVRAM) is a crucial component for DOE and DOD surveillance and defense applications. NVRAMs based upon ferroelectric materials (also known as FERAMs) are proven to work in radiation-rich environments and inherently require less power than many other NVRAM technologies. However, fabrication and integration challenges have led to state-of-the-art FERAMs still being fabricated using a 130nm process while competing phase-change memory (PRAM) has been demonstrated with a 20nm process. Use of block copolymer lithography is a promising approach to patterning at the sub-32nm scale, but is currently limited to self-assembly directly on Si or SiO{submore » 2} layers. Successful integration of ferroelectrics with discrete and addressable features of {approx}15-20nm would represent a 100-fold improvement in areal memory density and would enable more highly integrated electronic devices required for systems advances. Towards this end, we have developed a technique that allows us to carry out block copolymer self-assembly directly on a huge variety of different materials and have investigated the fabrication, integration, and characterization of electroceramic materials - primarily focused on solution-derived ferroelectrics - with discrete features of {approx}20nm and below. Significant challenges remain before such techniques will be capable of fabricating fully integrated NVRAM devices, but the tools developed for this effort are already finding broader use. This report introduces the nanopatterned NVRAM device concept as a mechanism for motivating the subsequent studies, but the bulk of the document will focus on the platform and technology development.« less

Microactuators as driving units for microbotic systems

NASA Astrophysics Data System (ADS)

Lehr, Heinz; Abel, S.; Doepper, J.; Ehrfeld, Wolfgang; Hagemann, B.; Kaemper, Klaus P.; Michel, Frank; Schulz, Ch.; Theurigen, C.

1996-12-01

The trend towards the integration of a multitude of functions in e.g. data end-, medical- and communication systems pushes the miniaturization of actuators for linear or rotational motions. Technical advantages of these devices are their low energy consumption, their potential for high precision positioning and their low inertial masses, which allow e.g. huge rotational frequencies. Appreciable forces and torques as well as appropriate mechanical interfaces to integrate these drive units into complete systems are necessary prerequisites for robotic applications, but rarely found up to now. Most of these difficulties arise due to the application of monolithic fabrication techniques, leading to structures of essentially planar nature and severe material restrictions. It turned out that only hybrid concepts and the assembly of components made from the most appropriate material open the chance to build up microactuators which are well suited for microrobotic systems. The contribution starts with a short description of the LIGA technique, which constitutes the major 3-D microfabrication method for the production of individual actuator components with structural heights of up to several millimeters made from a variety of function adapted materials. The assembling of these components results in microactuators with typical dimensions in the millimeter range. Examples are powerful electromagnetic micromotors, delivering torques much larger than one (mu) Nm and high rotational speeds which may be converted by use of LIGA fabricated gear-wheels to furthermore increase the torque. Huge forces are obtained in addition by use of microfabricated fluidic systems. Although small in size, the actuators still offer good handling opportunities and interfacing facilities to build up more complicated robotic systems.

Synthesis and characterization of inorganic materials precipitated into polymeric and novel liquid crystalline systems

NASA Astrophysics Data System (ADS)

Lubeck, Christopher Ryan

The use of nanostructured, hybrid materials possesses great future potential. Many examples of nanostructured materials exist within nature, such as animal bone, animal teeth, and seashells. This research, inspired by nature, strove to mimic salient properties of natural materials, utilizing methods observed within nature to produce materials. Further, this research increased the functionality of the templates from "mere" template to functional participant. Different chemical methods to produce hybrid materials were employed within this research to achieve these goals. First, electro-osmosis was utilized to drive ions into a polymeric matrix to form hybrid inorganic polymer material, creating a material inspired by naturally occurring bone or seashell in which the inorganic component provides strength and the polymeric material decreases the brittleness of the combined hybrid material. Second, self-assembled amphiphiles, forming higher ordered structures, acted as a template for inorganic cadmium sulfide. Electronically active molecules based on ethylene oxide and aniline segments were synthesized to create interaction between the templating material and the resulting inorganic cadmium sulfide. The templating process utilized self-assembly to create the inorganic structure through the interaction of the amphiphiles with water. The use of self-assembly is itself inspired by nature. Self-assembled structures are observed within living cells as cell walls and cell membranes are created through hydrophilic and hydrophobic interactions. Finally, the mesostructured inorganic cadmium sulfide was itself utilized as a template to form mesostructured copper sulfide.

Theory of Connectivity: Nature and Nurture of Cell Assemblies and Cognitive Computation

PubMed Central

Li, Meng; Liu, Jun; Tsien, Joe Z.

2016-01-01

Richard Semon and Donald Hebb are among the firsts to put forth the notion of cell assembly—a group of coherently or sequentially-activated neurons—to represent percept, memory, or concept. Despite the rekindled interest in this century-old idea, the concept of cell assembly still remains ill-defined and its operational principle is poorly understood. What is the size of a cell assembly? How should a cell assembly be organized? What is the computational logic underlying Hebbian cell assemblies? How might Nature vs. Nurture interact at the level of a cell assembly? In contrast to the widely assumed randomness within the mature but naïve cell assembly, the Theory of Connectivity postulates that the brain consists of the developmentally pre-programmed cell assemblies known as the functional connectivity motif (FCM). Principal cells within such FCM is organized by the power-of-two-based mathematical principle that guides the construction of specific-to-general combinatorial connectivity patterns in neuronal circuits, giving rise to a full range of specific features, various relational patterns, and generalized knowledge. This pre-configured canonical computation is predicted to be evolutionarily conserved across many circuits, ranging from these encoding memory engrams and imagination to decision-making and motor control. Although the power-of-two-based wiring and computational logic places a mathematical boundary on an individual’s cognitive capacity, the fullest intellectual potential can be brought about by optimized nature and nurture. This theory may also open up a new avenue to examining how genetic mutations and various drugs might impair or improve the computational logic of brain circuits. PMID:27199674

Programming function into mechanical forms by directed assembly of silk bulk materials

PubMed Central

Patel, Nereus; Duggan, Thomas; Perotto, Giovanni; Shirman, Elijah; Li, Chunmei; Kaplan, David L.; Omenetto, Fiorenzo G.

2017-01-01

We report simple, water-based fabrication methods based on protein self-assembly to generate 3D silk fibroin bulk materials that can be easily hybridized with water-soluble molecules to obtain multiple solid formats with predesigned functions. Controlling self-assembly leads to robust, machinable formats that exhibit thermoplastic behavior consenting material reshaping at the nanoscale, microscale, and macroscale. We illustrate the versatility of the approach by realizing demonstrator devices where large silk monoliths can be generated, polished, and reshaped into functional mechanical components that can be nanopatterned, embed optical function, heated on demand in response to infrared light, or can visualize mechanical failure through colorimetric chemistries embedded in the assembled (bulk) protein matrix. Finally, we show an enzyme-loaded solid mechanical part, illustrating the ability to incorporate biological function within the bulk material with possible utility for sustained release in robust, programmably shapeable mechanical formats. PMID:28028213

Controlled assembly of jammed colloidal shells on fluid droplets.

PubMed

Subramaniam, Anand Bala; Abkarian, Manouk; Stone, Howard A

2005-07-01

Assembly of colloidal particles on fluid interfaces is a promising technique for synthesizing two-dimensional microcrystalline materials useful in fields as diverse as biomedicine, materials science, mineral flotation and food processing. Current approaches rely on bulk emulsification methods, require further chemical and thermal treatments, and are restrictive with respect to the materials used. The development of methods that exploit the great potential of interfacial assembly for producing tailored materials have been hampered by the lack of understanding of the assembly process. Here we report a microfluidic method that allows direct visualization and understanding of the dynamics of colloidal crystal growth on curved interfaces. The crystals are periodically ejected to form stable jammed shells, which we refer to as colloidal armour. We propose that the energetic barriers to interfacial crystal growth and organization can be overcome by targeted delivery of colloidal particles through hydrodynamic flows. Our method allows an unprecedented degree of control over armour composition, size and stability.

Controlled assembly of jammed colloidal shells on fluid droplets

NASA Astrophysics Data System (ADS)

Subramaniam, Anand Bala; Abkarian, Manouk; Stone, Howard A.

2005-07-01

Assembly of colloidal particles on fluid interfaces is a promising technique for synthesizing two-dimensional microcrystalline materials useful in fields as diverse as biomedicine, materials science, mineral flotation and food processing. Current approaches rely on bulk emulsification methods, require further chemical and thermal treatments, and are restrictive with respect to the materials used. The development of methods that exploit the great potential of interfacial assembly for producing tailored materials have been hampered by the lack of understanding of the assembly process. Here we report a microfluidic method that allows direct visualization and understanding of the dynamics of colloidal crystal growth on curved interfaces. The crystals are periodically ejected to form stable jammed shells, which we refer to as colloidal armour. We propose that the energetic barriers to interfacial crystal growth and organization can be overcome by targeted delivery of colloidal particles through hydrodynamic flows. Our method allows an unprecedented degree of control over armour composition, size and stability.

Automated assembly in space

NASA Technical Reports Server (NTRS)

Srivastava, Sandanand; Dwivedi, Suren N.; Soon, Toh Teck; Bandi, Reddy; Banerjee, Soumen; Hughes, Cecilia

1989-01-01

The installation of robots and their use of assembly in space will create an exciting and promising future for the U.S. Space Program. The concept of assembly in space is very complicated and error prone and it is not possible unless the various parts and modules are suitably designed for automation. Certain guidelines are developed for part designing and for an easy precision assembly. Major design problems associated with automated assembly are considered and solutions to resolve these problems are evaluated in the guidelines format. Methods for gripping and methods for part feeding are developed with regard to the absence of gravity in space. The guidelines for part orientation, adjustments, compliances and various assembly construction are discussed. Design modifications of various fasteners and fastening methods are also investigated.

Protein Self-Assemblies That Can Generate, Hold, and Discharge Electric Potential in Response to Changes in Relative Humidity.

PubMed

Carter, Nathan A; Grove, Tijana Z

2018-05-30

Generation of electric potential upon external stimulus has attracted much attention for the development of highly functional sensors and devices. Herein, we report large-displacement, fast actuation in the self-assembled engineered repeat protein Consensus Tetratricopeptide Repeat protein (CTPR18) materials. The ionic nature of the CTPR18 protein coupled to the long-range alignment upon self-assembly results in the measured conductivity of 7.1 × 10 -2 S cm -1 , one of the highest reported for protein materials. The change of through-thickness morphological gradient in the self-assembled materials provides the means to select between faster, highly water-sensitive actuation or vastly increased mechanical strength. Tuning of the mode of motion, e.g., bending, twisting, and folding, is achieved by changing the morphological director. We further show that the highly ionic character of CTPR18 gives rise to piezo-like behavior in these materials, exemplified by low-voltage, ionically driven actuation and mechanically driven generation/discharge of voltage. This work contributes to our understanding of the emergence of stimuli-responsiveness in biopolymer assemblies.

A Common Probe Design for Multiple Planetary Destinations

NASA Technical Reports Server (NTRS)

Hwang, H. H.; Allen, G. A., Jr.; Alunni, A. I.; Amato, M. J.; Atkinson, D. H.; Bienstock, B. J.; Cruz, J. R.; Dillman, R. A.; Cianciolo, A. D.; Elliott, J. O.;

Engineering Plasmonic Nanocrystal Coupling through Template-Assisted Self-Assembly

NASA Astrophysics Data System (ADS)

Greybush, Nicholas J.

The construction of materials from nanocrystal building blocks represents a powerful new paradigm for materials design. Just as nature's materials orchestrate intricate combinations of atoms from the library of the periodic table, nanocrystal "metamaterials" integrate individual nanocrystals into larger architectures with emergent collective properties. The individual nanocrystal "meta-atoms" that make up these materials are themselves each a nanoscale atomic system with tailorable size, shape, and elemental composition, enabling the creation of hierarchical materials with predesigned structure at multiple length scales. However, an improved fundamental understanding of the interactions among individual nanocrystals is needed in order to translate this structural control into enhanced functionality. The ability to form precise arrangements of nanocrystals and measure their collective properties is therefore essential for the continued development of nanocrystal metamaterials. In this dissertation, we utilize template-assisted self-assembly and spatially-resolved spectroscopy to form and characterize individual nanocrystal oligomers. At the intersection of "top-down" and "bottom-up" nanoscale patterning schemes, template-assisted self-assembly combines the design freedom of lithography with the chemical control of colloidal synthesis to achieve unique nanocrystal configurations. Here, we employ shape-selective templates to assemble new plasmonic structures, including heterodimers of Au nanorods and upconversion phosphors, a series of hexagonally-packed Au nanocrystal oligomers, and triangular formations of Au nanorods. Through experimental analysis and numerical simulation, we elucidate the means through which inter-nanocrystal coupling imparts collective optical properties to the plasmonic assemblies. Our self-assembly and measurement strategy offers a versatile platform for exploring optical interactions in a wide range of material systems and application areas.

Nanoscale integration is the next frontier for nanotechnology

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

Picraux, Samuel T

2009-01-01

Nanoscale integration of materials and structures is the next critical step to exploit the promise of nanomaterials. Many novel and fascinating properties have been revealed for nanostructured materials. But if nanotechnology is to live up to its promise we must incorporate these nanoscale building blocks into functional systems that connect to the micro- and macroscale world. To do this we will inevitably need to understand and exploit the resulting combined unique properties of these integrated nanosystems. Much science waits to be discovered in the process. Nanoscale integration extends from the synthesis and fabrication of individual nanoscale building blocks, to themore » assembly of these building blocks into composite structures, and finally to the formation of complex functional systems. As illustrated in Figure 1, the building blocks may be homogeneous or heterogeneous, the composite materials may be nanocomposite or patterned structures, and the functional systems will involve additional combinations of materials. Nanoscale integration involves assembling diverse nanoscale materials across length scales to design and achieve new properties and functionality. At each stage size-dependent properties, the influence of surfaces in close proximity, and a multitude of interfaces all come into play. Whether the final system involves coherent electrons in a quantum computing approach, the combined flow of phonons and electrons for a high efficiency thermoelectric micro-generator, or a molecular recognition structure for bio-sensing, the combined effects of size, surface, and interface will be critical. In essence, one wants to combine the novel functions available through nanoscale science to achieve unique multi-functionalities not available in bulk materials. Perhaps the best-known example of integration is that of combining electronic components together into very large scale integrated circuits (VLSI). The integrated circuit has revolutionized electronics in many ways, from exploiting field-effect transistor devices and low power complementary logic to enable the electronic watch and hand calculator in the 1970's, to today's microprocessors and memories with billions of devices and a computational power not imagined a few decades ago. The manipulation of charges on a chip, the new concepts in combining devices for logic functions, and the new approaches to computation, information processing, and imaging have all emerged from Kilby and Noyce's simple concept of integrating devices on a single chip. Moving from hard to soft materials, a second more recent example of integration is the DNA microarray. These microarrays, with up to millions of elements in a planar array that can be optically read out, can simultaneously measure the expression of 10's of thousands of genes to study the effects of disease and treatment, or screen for single nucleotide polymorphisms for uses ranging from forensics to predisposition to disease. While still at an early stage, microarrays have revolutionized biosciences by providing the means to interrogate the complex genetic control of biological functions. Just as integrated circuits and microarrays have led to completely new functionalities and performance, the integration of nanoscale materials and structures is anticipated to lead to new performance and enable the design of new functionalities not previously envisioned. The fundamental questions underlying integration go beyond just complex fabrication or the engineering of known solutions; they lead to new discoveries and new science. The scientific challenges around nanoscale integration necessitate the development of new knowledge that is central to the advance of nanotechnology. To move forward one must address key science questions that arise in nanoscience integration and go beyond a single system or materials area. New science and discoveries especially await around three questions. How does one: (1) Control energy transfer and other interactions across interfaces and over mUltiple length scales? (2) Understand and control the interactions between nanoscale building blocks to assemble specific integrated structures? (3) Design and exploit interactions within assembled structures to achieve new properties and specific functionalities? These high level questions can serve to drive research, and to advance understanding of the complex phenomena and multifunctionality that may emerge from integration. For example, in photonics there is considerable effort to understand and control the response of nanoscale conducting structures on dielectrics, to allow one to localize, manipulate, and control electromagnetic energy in integrated systems such as in the field known as metamaterials. Essential to this area is a fundamental understanding of energy transfer across multiple length scales (question 1 above).« less

Method of fabricating composite structures

NASA Technical Reports Server (NTRS)

Sigur, W. A. (Inventor)

1990-01-01

A method of fabricating structures formed from composite materials by positioning the structure about a high coefficient of thermal expansion material, wrapping a graphite fiber overwrap about the structure, and thereafter heating the assembly to expand the high coefficient of thermal expansion material to forcibly compress the composite structure against the restraint provided by the graphite overwrap. The high coefficient of thermal expansion material is disposed about a mandrel with a release system therebetween, and with a release system between the material having the high coefficient of thermal expansion and the composite material, and between the graphite fibers and the composite structure. The heating may occur by inducing heat into the assembly by a magnetic field created by coils disposed about the assembly through which alternating current flows. The method permits structures to be formed without the use of an autoclave.

Method of fabricating composite structures

NASA Technical Reports Server (NTRS)

Sigur, Wanda A. (Inventor)

1992-01-01

A method of fabricating structures formed from composite materials by positioning the structure about a high coefficient of thermal expansion material, wrapping a graphite fiber overwrap about the structure, and thereafter heating the assembly to expand the high coefficient of thermal expansion material to forcibly compress the composite structure against the restraint provided by the graphite overwrap. The high coefficient of thermal expansion material is disposed about a mandrel with a release system therebetween, and with a release system between the material having the high coefficient of thermal expansion and the composite material, and between the graphite fibers and the composite structure. The heating may occur by inducing heat into the assembly by a magnetic field created by coils disposed about the assembly through which alternating current flows. The method permits structures to be formed without the use of an autoclave.

The on-board tailpipe emissions measurement system (TOTEMS) : proof\\0x2010 of\\0x2010concept.

DOT National Transportation Integrated Search

2009-06-03

An on-board tailpipe emissions instrumentation system was designed, assembled and tested as proof-of-concept : for the University of Vermonts Transportation Research Center (TRC) Signature Project #2 real-world vehicle : emissions data colle...

Self-Assembly and Nanostructures in Organogels Based on a Bolaform Cholesteryl Imide Compound with Conjugated Aromatic Spacer

PubMed Central

Jiao, Ti-Feng; Gao, Feng-Qing; Shen, Xi-Hai; Zhang, Qing-Rui; Zhang, Xian-Fu; Zhou, Jing-Xin; Gao, Fa-Ming

2013-01-01

The self-assembly of small functional molecules into supramolecular structures is a powerful approach toward the development of new nanoscale materials and devices. As a class of self-assembled materials, low weight molecular organic gelators, organized in special nanoarchitectures through specific non-covalent interactions, has become one of the hot topics in soft matter research due to their scientific values and many potential applications. Here, a bolaform cholesteryl imide compound with conjugated aromatic spacer was designed and synthesized. The gelation behaviors in 23 solvents were investigated as efficient low-molecular-mass organic gelator. The experimental results indicated that the morphologies and assembly modes of as-formed organogels can be regulated by changing the kinds of organic solvents. Scanning electron microscopy and atomic force microscopy observations revealed that the gelator molecule self-assemble into different aggregates, from wrinkle and belt to fiber with the change of solvents. Spectral studies indicated that there existed different H-bond formations between imide groups and assembly modes. Finally, some rational assembly modes in organogels were proposed and discussed. The present work may give some insight to the design and character of new organogelators and soft materials with special structures. PMID:28788428

Developing Novel Protein-based Materials using Ultrabithorax: Production, Characterization, and Functionalization

NASA Astrophysics Data System (ADS)

Huang, Zhao

2011-12-01

Compared to 'conventional' materials made from metal, glass, or ceramics, protein-based materials have unique mechanical properties. Furthermore, the morphology, mechanical properties, and functionality of protein-based materials may be optimized via sequence engineering for use in a variety of applications, including textile materials, biosensors, and tissue engineering scaffolds. The development of recombinant DNA technology has enabled the production and engineering of protein-based materials ex vivo. However, harsh production conditions can compromise the mechanical properties of protein-based materials and diminish their ability to incorporate functional proteins. Developing a new generation of protein-based materials is crucial to (i) improve materials assembly conditions, (ii) create novel mechanical properties, and (iii) expand the capacity to carry functional protein/peptide sequences. This thesis describes development of novel protein-based materials using Ultrabithorax, a member of the Hox family of proteins that regulate developmental pathways in Drosophila melanogaster. The experiments presented (i) establish the conditions required for the assembly of Ubx-based materials, (ii) generate a wide range of Ubx morphologies, (iii) examine the mechanical properties of Ubx fibers, (iv) incorporate protein functions to Ubx-based materials via gene fusion, (v) pattern protein functions within the Ubx materials, and (vi) examine the biocompatibility of Ubx materials in vitro. Ubx-based materials assemble at mild conditions compatible with protein folding and activity, which enables Ubx chimeric materials to retain the function of appended proteins in spatial patterns determined by materials assembly. Ubx-based materials also display mechanical properties comparable to existing protein-based materials and demonstrate good biocompatibility with living cells in vitro. Taken together, this research demonstrates the unique features and future potential of novel Ubx-based materials.

Material selection and assembly method of battery pack for compact electric vehicle

NASA Astrophysics Data System (ADS)

Lewchalermwong, N.; Masomtob, M.; Lailuck, V.; Charoenphonphanich, C.

2018-01-01

Battery packs become the key component in electric vehicles (EVs). The main costs of which are battery cells and assembling processes. The battery cell is indeed priced from battery manufacturers while the assembling cost is dependent on battery pack designs. Battery pack designers need overall cost as cheap as possible, but it still requires high performance and more safety. Material selection and assembly method as well as component design are very important to determine the cost-effectiveness of battery modules and battery packs. Therefore, this work presents Decision Matrix, which can aid in the decision-making process of component materials and assembly methods for a battery module design and a battery pack design. The aim of this study is to take the advantage of incorporating Architecture Analysis method into decision matrix methods by capturing best practices for conducting design architecture analysis in full account of key design components critical to ensure efficient and effective development of the designs. The methodology also considers the impacts of choice-alternatives along multiple dimensions. Various alternatives for materials and assembly techniques of battery pack are evaluated, and some sample costs are presented. Due to many components in the battery pack, only seven components which are positive busbar and Z busbar are represented in this paper for using decision matrix methods.

Compliant heterogeneous assemblies of micro-VCSELs as a new materials platform for integrated optoelectronics

NASA Astrophysics Data System (ADS)

Kang, Dongseok; Lee, Sung-Min; Kwong, Anthony; Yoon, Jongseung

2015-03-01

Despite many unique advantages, vertical cavity surface emitting lasers (VCSELs) have been available mostly on rigid, planar wafers over restricted areas, thereby limiting their usage for applications that can benefit from large-scale, programmable assemblies, hybrid integration with dissimilar materials and devices, or mechanically flexible constructions. Here, materials design and fabrication strategies that address these limitations of conventional VCSELs are presented. Specialized design of epitaxial materials and etching processes, together with printing-based deterministic assemblies and substrate thermal engineering, enabled defect-free release of microscale VCSELs and their device- and circuit-level implementation on non-native, flexible substrates with performance comparable to devices on the growth substrate.

Technological development of spectral filters for Sentinel-2

NASA Astrophysics Data System (ADS)

Schröter, Karin; Schallenberg, Uwe; Mohaupt, Matthias

2017-11-01

In the frame of the initiative for Global Monitoring for Environment and Security (GMES), jointly undertaken by the European Commission and the European Space Agency a technological development of two filter assemblies was performed for the Multi- Spectral Instrument (MSI) for Sentinel-2. The multispectral pushbroom imaging of the Earth will be performed in 10 VNIR bands (from 443 nm to 945nm) and 3 SWIR bands (from 1375 nm to 2190 nm). Possible filter coating techniques and masking concepts were considered in the frame of trade-off studies. The selected deposition concept is based on self-blocked all-dielectric multilayer band pass filter. Band pass and blocking characteristic is deposited on the space side of a single filter substrate whereas the detector side of the substrate has an antireflective coating. The space- and detector side masking design is realized by blades integrated in the mechanical parts including the mechanical interface to the filter assembly support on the MSI focal plane. The feasibility and required performance of the VNIR Filter Assembly and SWIR Filter Assembly were successfully demonstrated by breadboarding. Extensive performance tests of spectral and optical parameters and environmental tests (radiation, vibration, shock, thermal vacuum cycling, humidity) were performed on filter stripe- and filter assembly level. The presentation will contain a detailed description of the filter assembly design and the results of the performance and environmental tests.

Enzymatically Active Microgels from Self-Assembling Protein Nanofibrils for Microflow Chemistry.

PubMed

Zhou, Xiao-Ming; Shimanovich, Ulyana; Herling, Therese W; Wu, Si; Dobson, Christopher M; Knowles, Tuomas P J; Perrett, Sarah

2015-06-23

Amyloid fibrils represent a generic class of protein structure associated with both pathological states and with naturally occurring functional materials. This class of protein nanostructure has recently also emerged as an excellent foundation for sophisticated functional biocompatible materials including scaffolds and carriers for biologically active molecules. Protein-based materials offer the potential advantage that additional functions can be directly incorporated via gene fusion producing a single chimeric polypeptide that will both self-assemble and display the desired activity. To succeed, a chimeric protein system must self-assemble without the need for harsh triggering conditions which would damage the appended functional protein molecule. However, the micrometer to nanoscale patterning and morphological control of protein-based nanomaterials has remained challenging. This study demonstrates a general approach for overcoming these limitations through the microfluidic generation of enzymatically active microgels that are stabilized by amyloid nanofibrils. The use of scaffolds formed from biomaterials that self-assemble under mild conditions enables the formation of catalytic microgels while maintaining the integrity of the encapsulated enzyme. The enzymatically active microgel particles show robust material properties and their porous architecture allows diffusion in and out of reactants and products. In combination with microfluidic droplet trapping approaches, enzymatically active microgels illustrate the potential of self-assembling materials for enzyme immobilization and recycling, and for biological flow-chemistry. These design principles can be adopted to create countless other bioactive amyloid-based materials with diverse functions.

Development of a Nano-Satellite Micro-Coupling Mechanism with Characterization of a Shape Memory Alloy Interference Joint

DTIC Science & Technology

2010-12-01

satellite incorporation are explored by assembly and experimentation. Research on pseudoelastic material properties , analytical predictions, and...are explored by assembly and experimentation. Research on pseudoelastic material properties , analytical predictions, and tests of coupling strengths...20  Table 2.  Material Properties Used in Micro-Coupling Predicted Strength Calculations

Conformation-Directed Formation of Self-Healing Diblock Copolypeptide Hydrogels via Polyion Complexation.

PubMed

Sun, Yintao; Wollenberg, Alexander L; O'Shea, Timothy Mark; Cui, Yanxiang; Zhou, Z Hong; Sofroniew, Michael V; Deming, Timothy J

2017-10-25

Synthetic diblock copolypeptides were designed to incorporate oppositely charged ionic segments that form β-sheet-structured hydrogel assemblies via polyion complexation when mixed in aqueous media. The observed chain conformation directed assembly was found to be required for efficient hydrogel formation and provided distinct and useful properties to these hydrogels, including self-healing after deformation, microporous architecture, and stability against dilution in aqueous media. While many promising self-assembled materials have been prepared using disordered or liquid coacervate polyion complex (PIC) assemblies, the use of ordered chain conformations in PIC assemblies to direct formation of new supramolecular morphologies is unprecedented. The promising attributes and unique features of the β-sheet-structured PIC hydrogels described here highlight the potential of harnessing conformational order derived from PIC assembly to create new supramolecular materials.

Framework for Defining and Assessing Benefits of a Modular Assembly Design Approach for Exploration Systems

NASA Technical Reports Server (NTRS)

Dorsey, John T.; Collins, Timothy J.; Moe, Rud V.; Doggett,. William R.

2006-01-01

A comprehensive modular assembly system model has been proposed that extends the art from modular hardware, to include in-space assembly, servicing and repair and it s critical components of infrastructure, agents and assembly operations. Benefits of modular assembly have been identified and a set of metrics defined that extends the art beyond the traditional measures of performance, with emphasis on criteria that allow life-cycle mission costs to be used as a figure of merit (and include all substantive terms that have an impact on the evaluation). The modular assembly approach was used as a basis for developing a Solar Electric Transfer Vehicle (SETV) concept and three modular assembly scenarios were developed. The modular assembly approach also allows the SETV to be entered into service much earlier than competing conventional configurations and results in a great deal of versatility in accommodating different launch vehicle payload capabilities, allowing for modules to be pre-assembled before launch or assembled on orbit, without changing the space vehicle design.

Influences of surface charge, size, and concentration of colloidal nanoparticles on fabrication of self-organized porous silica in film and particle forms.

PubMed

Nandiyanto, Asep Bayu Dani; Suhendi, Asep; Arutanti, Osi; Ogi, Takashi; Okuyama, Kikuo

2013-05-28

Studies on preparation of porous material have attracted tremendous attention because existence of pores can provide material with excellent performances. However, current preparation reports described successful production of porous material with only partial information on charges, interactions, sizes, and compositions of the template and host materials. In this report, influences of self-assembly parameters (i.e., surface charge, size, and concentration of colloidal nanoparticles) on self-organized porous material fabrication were investigated. Silica nanoparticles (as a host material) and polystyrene (PS) spheres (as a template) were combined to produce self-assembly porous materials in film and particle forms. The experimental results showed that the porous structure and pore size were controllable and strongly depended on the self-assembly parameters. Materials containing highly ordered pores were effectively created only when process parameters fall within appropriate conditions (i.e., PS surface charge ≤ -30 mV; silica-to-PS size ratio ≤0.078; and silica-to-PS mass ratio of about 0.50). The investigation of the self-assembly parameter landscape was also completed using geometric considerations. Because optimization of these parameters provides significant information in regard to practical uses, results of this report could be relevant to other functional properties.

Method of forming and assembly of parts

DOEpatents

Ripley, Edward B.

2010-12-28

A method of assembling two or more parts together that may be metal, ceramic, metal and ceramic parts, or parts that have different CTE. Individual parts are formed and sintered from particles that leave a network of interconnecting porosity in each sintered part. The separate parts are assembled together and then a fill material is infiltrated into the assembled, sintered parts using a method such as capillary action, gravity, and/or pressure. The assembly is then cured to yield a bonded and fully or near-fully dense part that has the desired physical and mechanical properties for the part's intended purpose. Structural strength may be added to the parts by the inclusion of fibrous materials.

49 CFR 195.130 - Fabricated assemblies.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false Fabricated assemblies. 195.130 Section 195.130 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Design Requirements § 195.130 Fabricated assemblies. Each fabricated assembly to be installed in a...

49 CFR 195.130 - Fabricated assemblies.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Fabricated assemblies. 195.130 Section 195.130 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Design Requirements § 195.130 Fabricated assemblies. Each fabricated assembly to be installed in a...

49 CFR 195.130 - Fabricated assemblies.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Fabricated assemblies. 195.130 Section 195.130 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Design Requirements § 195.130 Fabricated assemblies. Each fabricated assembly to be installed in a...

49 CFR 195.130 - Fabricated assemblies.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 3 2012-10-01 2012-10-01 false Fabricated assemblies. 195.130 Section 195.130 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Design Requirements § 195.130 Fabricated assemblies. Each fabricated assembly to be installed in a...

49 CFR 195.130 - Fabricated assemblies.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 3 2014-10-01 2014-10-01 false Fabricated assemblies. 195.130 Section 195.130 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Design Requirements § 195.130 Fabricated assemblies. Each fabricated assembly to be installed in a...

Electrodynamic tailoring of self-assembled three-dimensional electrospun constructs

NASA Astrophysics Data System (ADS)

Reis, Tiago C.; Correia, Ilídio J.; Aguiar-Ricardo, Ana

2013-07-01

The rational design of three-dimensional electrospun constructs (3DECs) can lead to striking topographies and tailored shapes of electrospun materials. This new generation of materials is suppressing some of the current limitations of the usual 2D non-woven electrospun fiber mats, such as small pore sizes or only flat shaped constructs. Herein, we pursued an explanation for the self-assembly of 3DECs based on electrodynamic simulations and experimental validation. We concluded that the self-assembly process is driven by the establishment of attractive electrostatic forces between the positively charged aerial fibers and the already collected ones, which tend to acquire a negatively charged network oriented towards the nozzle. The in situ polarization degree is strengthened by higher amounts of clustered fibers, and therefore the initial high density fibrous regions are the preliminary motifs for the self-assembly mechanism. As such regions increase their in situ polarization electrostatic repulsive forces will appear, favoring a competitive growth of these self-assembled fibrous clusters. Highly polarized regions will evidence higher distances between consecutive micro-assembled fibers (MAFs). Different processing parameters - deposition time, electric field intensity, concentration of polymer solution, environmental temperature and relative humidity - were evaluated in an attempt to control material's design.The rational design of three-dimensional electrospun constructs (3DECs) can lead to striking topographies and tailored shapes of electrospun materials. This new generation of materials is suppressing some of the current limitations of the usual 2D non-woven electrospun fiber mats, such as small pore sizes or only flat shaped constructs. Herein, we pursued an explanation for the self-assembly of 3DECs based on electrodynamic simulations and experimental validation. We concluded that the self-assembly process is driven by the establishment of attractive electrostatic forces between the positively charged aerial fibers and the already collected ones, which tend to acquire a negatively charged network oriented towards the nozzle. The in situ polarization degree is strengthened by higher amounts of clustered fibers, and therefore the initial high density fibrous regions are the preliminary motifs for the self-assembly mechanism. As such regions increase their in situ polarization electrostatic repulsive forces will appear, favoring a competitive growth of these self-assembled fibrous clusters. Highly polarized regions will evidence higher distances between consecutive micro-assembled fibers (MAFs). Different processing parameters - deposition time, electric field intensity, concentration of polymer solution, environmental temperature and relative humidity - were evaluated in an attempt to control material's design. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr01668d

Fabricating biomedical origami: a state-of-the-art review

PubMed Central

Johnson, Meredith; Chen, Yue; Hovet, Sierra; Xu, Sheng; Wood, Bradford; Ren, Hongliang; Tokuda, Junichi; Tse, Zion Tsz Ho

2018-01-01

Purpose Origami-based biomedical device design is an emerging technology due to its ability to be deployed from a minimal foldable pattern to a larger volume. This paper aims to review state-of-the-art origami structures applied in the medical device field. Methods Publications and reports of origami structure related to medical device design from the past 10 years are reviewed and categorized according to engineering specifications, including the application field, fabrication material, size/volume, deployment method, manufacturability, and advantages. Results This paper presents an overview of the biomedical applications of devices based on origami structures, including disposable sterilization covers, cardiac catheterization, stent grafts, encapsulation and microsurgery, gastrointestinal microsurgery, laparoscopic surgical grippers, microgrippers, microfluidic devices, and drug delivery. Challenges in terms of materials and fabrication, assembly, modeling and computation design, and clinical adoptability are discussed at the end of this paper to provide guidance for future origami-based design in the medical device field. Conclusion Concepts from origami can be used to design and develop novel medical devices. Origami-based medical device design is currently progressing, with researchers improving design methods, materials, fabrication techniques, and folding efficiency. PMID:28260164

Large-area, lightweight and thick biomimetic composites with superior material properties via fast, economic, and green pathways.

PubMed

Walther, Andreas; Bjurhager, Ingela; Malho, Jani-Markus; Pere, Jaakko; Ruokolainen, Janne; Berglund, Lars A; Ikkala, Olli

2010-08-11

Although remarkable success has been achieved to mimic the mechanically excellent structure of nacre in laboratory-scale models, it remains difficult to foresee mainstream applications due to time-consuming sequential depositions or energy-intensive processes. Here, we introduce a surprisingly simple and rapid methodology for large-area, lightweight, and thick nacre-mimetic films and laminates with superior material properties. Nanoclay sheets with soft polymer coatings are used as ideal building blocks with intrinsic hard/soft character. They are forced to rapidly self-assemble into aligned nacre-mimetic films via paper-making, doctor-blading or simple painting, giving rise to strong and thick films with tensile modulus of 45 GPa and strength of 250 MPa, that is, partly exceeding nacre. The concepts are environmentally friendly, energy-efficient, and economic and are ready for scale-up via continuous roll-to-roll processes. Excellent gas barrier properties, optical translucency, and extraordinary shape-persistent fire-resistance are demonstrated. We foresee advanced large-scale biomimetic materials, relevant for lightweight sustainable construction and energy-efficient transportation.

Fabricating biomedical origami: a state-of-the-art review.

PubMed

Johnson, Meredith; Chen, Yue; Hovet, Sierra; Xu, Sheng; Wood, Bradford; Ren, Hongliang; Tokuda, Junichi; Tse, Zion Tsz Ho

2017-11-01

Origami-based biomedical device design is an emerging technology due to its ability to be deployed from a minimal foldable pattern to a larger volume. This paper aims to review state-of-the-art origami structures applied in the medical device field. Publications and reports of origami structure related to medical device design from the past 10 years are reviewed and categorized according to engineering specifications, including the application field, fabrication material, size/volume, deployment method, manufacturability, and advantages. This paper presents an overview of the biomedical applications of devices based on origami structures, including disposable sterilization covers, cardiac catheterization, stent grafts, encapsulation and microsurgery, gastrointestinal microsurgery, laparoscopic surgical grippers, microgrippers, microfluidic devices, and drug delivery. Challenges in terms of materials and fabrication, assembly, modeling and computation design, and clinical adoptability are discussed at the end of this paper to provide guidance for future origami-based design in the medical device field. Concepts from origami can be used to design and develop novel medical devices. Origami-based medical device design is currently progressing, with researchers improving design methods, materials, fabrication techniques, and folding efficiency.

Biomimetic Strategies for Sensing Biological Species

PubMed Central

Hussain, Munawar; Wackerlig, Judith; Lieberzeit, Peter A.

2013-01-01

The starting point of modern biosensing was the application of actual biological species for recognition. Increasing understanding of the principles underlying such recognition (and biofunctionality in general), however, has triggered a dynamic field in chemistry and materials sciences that aims at joining the best of two worlds by combining concepts derived from nature with the processability of manmade materials, e.g., sensitivity and ruggedness. This review covers different biomimetic strategies leading to highly selective (bio)chemical sensors: the first section covers molecularly imprinted polymers (MIP) that attempt to generate a fully artificial, macromolecular mold of a species in order to detect it selectively. A different strategy comprises of devising polymer coatings to change the biocompatibility of surfaces that can also be used to immobilized natural receptors/ligands and thus stabilize them. Rationally speaking, this leads to self-assembled monolayers closely resembling cell membranes, sometimes also including bioreceptors. Finally, this review will highlight some approaches to generate artificial analogs of natural recognition materials and biomimetic approaches in nanotechnology. It mainly focuses on the literature published since 2005. PMID:25587400

Polymeric Helical Microactuators: Achieving High Speed and High Extension.

NASA Astrophysics Data System (ADS)

Kim, Yongjin; Crosby, Alfred

We proposed novel concepts of actuation mechanism and fabrication method to induce fast and highly extensional motion in polymeric actuators. Exceptionally high extensional strain over 1400% was realized by the geometric transformation from a helix to a stretched ribbon in a responsive and reversible manner. As a model system, sub-micron sized helices were fabricated from a self-assembled, UV-cured, thermo-responsive polymer. By controlling the size and the geometrical asymmetries in the system, a combined effect of surface tension and differential volumetric strain during the transition between swollen-deswollen state induced by phase transition of the material was successfully utilized to generate torsional stresses in the system. For the full understanding of the results, a finite element analysis and measurements on the poroelastic properties of the material were conducted as well as a demonstration on macroscopic system made with PDMS. Finally, remaining questions on the chirality of helices were presented. This material is based upon work supported by, or in part by, the U. S. Army Research Laboratory and the U. S. Army Research Office under contract/Grant Number W911NF-15-1-0358.

Hierarchical porous carbons with layer-by-layer motif architectures from confined soft-template self-assembly in layered materials

NASA Astrophysics Data System (ADS)

Wang, Jie; Tang, Jing; Ding, Bing; Malgras, Victor; Chang, Zhi; Hao, Xiaodong; Wang, Ya; Dou, Hui; Zhang, Xiaogang; Yamauchi, Yusuke

2017-06-01

Although various two-dimensional (2D) nanomaterials have been explored as promising capacitive materials due to their unique layered structure, their natural restacking tendency impedes electrolyte transport and significantly restricts their practical applications. Herein, we synthesize all-carbon layer-by-layer motif architectures by introducing 2D ordered mesoporous carbons (OMC) within the interlayer space of 2D nanomaterials. As a proof of concept, MXenes are selected as 2D hosts to design 2D-2D heterostructures. Further removing the metal elements from MXenes leads to the formation of all-carbon 2D-2D heterostructures consisting of alternating layers of MXene-derived carbon (MDC) and OMC. The OMC layers intercalated with the MDC layers not only prevent restacking but also facilitate ion diffusion and electron transfer. The performance of the obtained hybrid carbons as supercapacitor electrodes demonstrates their potential for upcoming electronic devices. This method allows to overcome the restacking and blocking of 2D nanomaterials by constructing ion-accessible OMC within the 2D host material.

Polyhedral Boranes: A Versatile Building Block for Nanoporous Materials

NASA Astrophysics Data System (ADS)

Clingerman, Daniel Jon

The studies described in this dissertation examine several new concepts related to polyhedral boranes and their applications towards the synthesis of novel nanoporous materials. The unique thermal and chemical robustness, rigidity, quasi-spherical geometry, and high boron content of polyhedral boranes are explored to generate materials not possible with typical organic synthons. Aside from the fundamental synthetic work, this work was also aimed at solving larger global issues such as energy storage and new routes to therapeutics. Chapter 2 highlights the discovery of the first highly porous carborane-based metal-organic framework, where the spherical nature of the carborane increases volumetric surface area without reducing pore volume. Chapter 3 examines the first tritopic carborane-based ligand and the stabilizing effect the rigid, sterically bulky carboranyl groups have on highly porous topologies not stable with typical organic ligands. Chapters 4 and 5 describe the use of polyhedral borane-based ligands as a means to influence and generate unexpected topologies. Lastly, chapter 6 explores using a simple carborane-based ligand that harnesses the power of coordination-driven assembly to rapidly generate a high boron-containing supramolecular cuboctahedron.

Guided molecular self-assembly: a review of recent efforts

NASA Astrophysics Data System (ADS)

Huie, Jiyun C.

2003-04-01

This paper serves as an introductory review of significant and novel successes achieved in the fields of nanotechnology, particularly in the formation of nanostructures using guided molecular self-assembly methods. Self-assembly is a spontaneous process by which molecules and nanophase entities may materialize into organized aggregates or networks. Through various interactive mechanisms of self-assembly, such as electrostatics, chemistry, surface properties, and via other mediating agents, the technique proves indispensable to recent functional materials and device realizations. The discussion will extend to spontaneous and Langmuir-Blodgett formation of self-assembled monolayers on various substrates, and a number of different categories of self-assembly techniques based on the type of interaction exploited. Combinatorial techniques, known as soft lithography, of micro-contact printing and dip-pen nanolithography, which can be effectively used to up-size nanostructured molecular assemblies to submicrometer and micrometer scale patterns, will also be mentioned.

Supra-Nanoparticle Functional Assemblies through Programmable Stacking

DOE PAGES

Tian, Cheng; Cordeiro, Marco Aurelio L.; Lhermitte, Julien; ...

2017-05-25

The quest for the by-design assembly of material and devices from nanoscale inorganic components is well recognized. Conventional self-assembly is often limited in its ability to control material morphology and structure simultaneously. We report a general method of assembling nanoparticles in a linear “pillar” morphology with regulated internal configurations. Our approach is inspired by supramolecular systems, where intermolecular stacking guides the assembly process to form diverse linear morphologies. Programmable stacking interactions were realized through incorporation of DNA coded recognition between the designed planar nanoparticle clusters. This resulted in the formation of multilayered pillar architectures with a well-defined internal nanoparticle organization.more » Furthermore, by controlling the number, position, size, and composition of the nanoparticles in each layer, a broad range of nanoparticle pillars were assembled and characterized in detail. In addition, we demonstrated the utility of this stacking assembly strategy for investigating plasmonic and electrical transport properties.« less

Supra-Nanoparticle Functional Assemblies through Programmable Stacking

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

Tian, Cheng; Cordeiro, Marco Aurelio L.; Lhermitte, Julien

The quest for the by-design assembly of material and devices from nanoscale inorganic components is well recognized. Conventional self-assembly is often limited in its ability to control material morphology and structure simultaneously. We report a general method of assembling nanoparticles in a linear “pillar” morphology with regulated internal configurations. Our approach is inspired by supramolecular systems, where intermolecular stacking guides the assembly process to form diverse linear morphologies. Programmable stacking interactions were realized through incorporation of DNA coded recognition between the designed planar nanoparticle clusters. This resulted in the formation of multilayered pillar architectures with a well-defined internal nanoparticle organization.more » Furthermore, by controlling the number, position, size, and composition of the nanoparticles in each layer, a broad range of nanoparticle pillars were assembled and characterized in detail. In addition, we demonstrated the utility of this stacking assembly strategy for investigating plasmonic and electrical transport properties.« less

Supra-Nanoparticle Functional Assemblies through Programmable Stacking.

PubMed

Tian, Cheng; Cordeiro, Marco Aurelio L; Lhermitte, Julien; Xin, Huolin L; Shani, Lior; Liu, Mingzhao; Ma, Chunli; Yeshurun, Yosef; DiMarzio, Donald; Gang, Oleg

2017-07-25

The quest for the by-design assembly of material and devices from nanoscale inorganic components is well recognized. Conventional self-assembly is often limited in its ability to control material morphology and structure simultaneously. Here, we report a general method of assembling nanoparticles in a linear "pillar" morphology with regulated internal configurations. Our approach is inspired by supramolecular systems, where intermolecular stacking guides the assembly process to form diverse linear morphologies. Programmable stacking interactions were realized through incorporation of DNA coded recognition between the designed planar nanoparticle clusters. This resulted in the formation of multilayered pillar architectures with a well-defined internal nanoparticle organization. By controlling the number, position, size, and composition of the nanoparticles in each layer, a broad range of nanoparticle pillars were assembled and characterized in detail. In addition, we demonstrated the utility of this stacking assembly strategy for investigating plasmonic and electrical transport properties.

Integral gas seal for fuel cell gas distribution assemblies and method of fabrication

DOEpatents

Dettling, Charles J.; Terry, Peter L.

1985-03-19

A porous gas distribution plate assembly for a fuel cell, such as a bipolar assembly, includes an inner impervious region wherein the bipolar assembly has good surface porosity but no through-plane porosity and wherein electrical conductivity through the impervious region is maintained. A hot-pressing process for forming the bipolar assembly includes placing a layer of thermoplastic sealant material between a pair of porous, electrically conductive plates, applying pressure to the assembly at elevated temperature, and allowing the assembly to cool before removing the pressure whereby the layer of sealant material is melted and diffused into the porous plates to form an impervious bond along a common interface between the plates holding the porous plates together. The distribution of sealant within the pores along the surface of the plates provides an effective barrier at their common interface against through-plane transmission of gas.

Method of fabricating an integral gas seal for fuel cell gas distribution assemblies

DOEpatents

Dettling, Charles J.; Terry, Peter L.

1988-03-22

A porous gas distribution plate assembly for a fuel cell, such as a bipolar assembly, includes an inner impervious region wherein the bipolar assembly has good surface porosity but no through-plane porosity and wherein electrical conductivity through the impervious region is maintained. A hot-pressing process for forming the bipolar assembly includes placing a layer of thermoplastic sealant material between a pair of porous, electrically conductive plates, applying pressure to the assembly at elevated temperature, and allowing the assembly to cool before removing the pressure whereby the layer of sealant material is melted and diffused into the porous plates to form an impervious bond along a common interface between the plates holding the porous plates together. The distribution of sealant within the pores along the surface of the plates provides an effective barrier at their common interface against through-plane transmission of gas.

Self-assembly of water-soluble nanocrystals

DOEpatents

Fan, Hongyou [Albuquerque, NM; Brinker, C Jeffrey [Albuquerque, NM; Lopez, Gabriel P [Albuquerque, NM

2012-01-10

A method for forming an ordered array of nanocrystals where a hydrophobic precursor solution with a hydrophobic core material in an organic solvent is added to a solution of a surfactant in water, followed by removal of a least a portion of the organic solvent to form a micellar solution of nanocrystals. A precursor co-assembling material, generally water-soluble, that can co-assemble with individual micelles formed in the micellar solution of nanocrystals can be added to this micellar solution under specified reaction conditions (for example, pH conditions) to form an ordered-array mesophase material. For example, basic conditions are used to precipitate an ordered nanocrystal/silica array material in bulk form and acidic conditions are used to form an ordered nanocrystal/silica array material as a thin film.

A Module for Hospital Central Processing Technicians on Decontamination, Assembly and Wrapping Concepts of GYN Hysterectomy Instruments.

ERIC Educational Resources Information Center

Wojcik, Roseann B.; Moseley, James L.

This learning module can be used as an orientation guide, inservice tool, or resource guide for hospital central processing department technicians and instructors. It contains information sheets, worksheets, worksheet answers, a posttest, and posttest answers on correct procedures for decontaminating, assembling, and wrapping the medical…

Space Shuttle Projects

NASA Image and Video Library

1985-11-30

The crew assigned to the STS-61B mission included Bryan D. O’Conner, pilot; Brewster H. Shaw, commander; Charles D. Walker, payload specialist; mission specialists Jerry L. Ross, Mary L. Cleave, and Sherwood C. Spring; and Rodolpho Neri Vela, payload specialist. Launched aboard the Space Shuttle Atlantis November 28, 1985 at 7:29:00 pm (EST), the STS-61B mission’s primary payload included three communications satellites: MORELOS-B (Mexico); AUSSAT-2 (Australia); and SATCOM KU-2 (RCA Americom). Two experiments were conducted to test assembling erectable structures in space: EASE (Experimental Assembly of Structures in Extravehicular Activity), and ACCESS (Assembly Concept for Construction of Erectable Space Structure). In a joint venture between NASA/Langley Research Center in Hampton, Virginia and the Marshall Space Flight Center (MSFC), EASE and ACCESS were developed and demonstrated at MSFC's Neutral Buoyancy Simulator (NBS). The primary objective of this experiment was to test the structural assembly concepts for suitability as the framework for larger space structures and to identify ways to improve the productivity of space construction. In this STS-61B onboard photo, astronaut Ross was working on the ACCESS experiment during an Extravehicular Activity (EVA).

Space Shuttle Projects

NASA Image and Video Library

1985-11-30

The crew assigned to the STS-61B mission included Bryan D. O’Conner, pilot; Brewster H. Shaw, commander; Charles D. Walker, payload specialist; mission specialists Jerry L. Ross, Mary L. Cleave, and Sherwood C. Spring; and Rodolpho Neri Vela, payload specialist. Launched aboard the Space Shuttle Atlantis November 28, 1985 at 7:29:00 pm (EST), the STS-61B mission’s primary payload included three communications satellites: MORELOS-B (Mexico); AUSSAT-2 (Australia); and SATCOM KU-2 (RCA Americom). Two experiments were conducted to test assembling erectable structures in space: EASE (Experimental Assembly of Structures in Extravehicular Activity), and ACCESS (Assembly Concept for Construction of Erectable Space Structure). In a joint venture between NASA/Langley Research Center in Hampton, Virginia, and the Marshall Space Flight Center (MSFC), EASE and ACCESS were developed and demonstrated at MSFC's Neutral Buoyancy Simulator (NBS). In this STS-61B onboard photo, astronaut Ross works on ACCESS high above the orbiter. The primary objective of these experiments was to test the structural assembly concepts for suitability as the framework for larger space structures and to identify ways to improve the productivity of space construction.

Space Shuttle Projects

NASA Image and Video Library

1985-11-30

The crew assigned to the STS-61B mission included Bryan D. O’Conner, pilot; Brewster H. Shaw, commander; Charles D. Walker, payload specialist; mission specialists Jerry L. Ross, Mary L. Cleave, and Sherwood C. Spring; and Rodolpho Neri Vela, payload specialist. Launched aboard the Space Shuttle Atlantis November 28, 1985 at 7:29:00 pm (EST), the STS-61B mission’s primary payload included three communications satellites: MORELOS-B (Mexico); AUSSAT-2 (Australia); and SATCOM KU-2 (RCA Americom). Two experiments were conducted to test assembling erectable structures in space: EASE (Experimental Assembly of Structures in Extravehicular Activity), and ACCESS (Assembly Concept for Construction of Erectable Space Structure). In a joint venture between NASA/Langley Research Center in Hampton, Virginia, and the Marshall Space Flight Center (MSFC), the EASE and ACCESS were developed and demonstrated at MSFC's Neutral Buoyancy Simulator (NBS). In this STS-61B onboard photo, astronaut Spring was working on the EASE during an Extravehicular Activity (EVA). The primary objective of this experiment was to test the structural assembly concepts for suitability as the framework for larger space structures and to identify ways to improve the productivity of space construction.

Conceptual Design of the Nuclear Electronic Xenon Ion System (NEXIS)

NASA Technical Reports Server (NTRS)

Monheiser, Jeff; Polk, Jay; Randolph, Tom

2004-01-01

In support of the NEXIS program, Aerojet-Redmond Operations, with review and input from the JPL and Boeing, has completed the design for a development model (DM) discharge chamber assembly and main discharge cathode assembly. These efforts along with the work by JPL to develop the carbon-carbon-composite ion optics assembly have resulted in a complete ion engine design. The goal of the NEXIS program is to significantly advance the current state of the art by developing an ion engine capable of operating at an input power of 20kW, an Isp of 7500 sec and have a total xenon through put capability of 2000 kg. In this paper we will describe the methodology used to design the discharge chamber and cathode assemblies and describe the resulting final design. Specifics will include the concepts used for the mounting of the ion optics along with the concepts used for the gimbal mounts. In addition, we will present results of a vibrational analysis showing how the engine will respond to a typical Delta IV heavy vibration spectrum.

On the design of composite protein-quantum dot biomaterials via self-assembly.

PubMed

Majithia, Ravish; Patterson, Jan; Bondos, Sarah E; Meissner, Kenith E

2011-10-10

Incorporation of nanoparticles during the hierarchical self-assembly of protein-based materials can impart function to the resulting composite materials. Herein we demonstrate that the structure and nanoparticle distribution of composite fibers are sensitive to the method of nanoparticle addition and the physicochemical properties of both the nanoparticle and the protein. Our model system consists of a recombinant enhanced green fluorescent protein-Ultrabithorax (EGFP-Ubx) fusion protein and luminescent CdSe-ZnS core-shell quantum dots (QDs), allowing us to optically assess the distribution of both the protein and nanoparticle components within the composite material. Although QDs favorably interact with EGFP-Ubx monomers, the relatively rough surface morphology of composite fibers suggests EGFP-Ubx-QD conjugates impact self-assembly. Indeed, QDs templated onto EGFP-Ubx film post-self-assembly can be subsequently drawn into smooth composite fibers. Additionally, the QD surface charge impacts QD distribution within the composite material, indicating that surface charge plays an important role in self-assembly. QDs with either positively or negatively charged coatings significantly enhance fiber extensibility. Conversely, QDs coated with hydrophobic moieties and suspended in toluene produce composite fibers with a heterogeneous distribution of QDs and severely altered fiber morphology, indicating that toluene severely disrupts Ubx self-assembly. Understanding factors that impact the protein-nanoparticle interaction enables manipulation of the structure and mechanical properties of composite materials. Since proteins interact with nanoparticle surface coatings, these results should be applicable to other types of nanoparticles with similar chemical groups on the surface.

A study of material composition disclosure practices in green footwear products.

PubMed

Jacques, Jocelise J; Guimarães, Lia B M

2012-01-01

This work is based on the study of pioneering sustainable product development initiatives, and the analysis was guided by the cradle-to-cradle concept, which sees the waste of a given process as raw material for another, just like it happens in nature. Several studies on human factors have focused on factory conditions and workers dealing with product assembly. This research, however, relates more to consumer behavior, product use and end-of-life. The purchase of more environmentally- friendly products, in particular, is heavily influenced by the information made available by the companies. In this scenario, this article discusses three early but notable efforts on green product development, focusing on the disclosure practices adopted by the companies regarding the composition of their products. Research and data collection has focused on the footwear industry, whose products satisfy a basic human need and are ubiquitous worldwide. The use of hazardous materials and chemicals in shoe manufacturing, particularly the use of chromium - a highly toxic element - in addition to toxic solvents and adhesives and non-recyclable synthetic materials can pose serious risks to human health and the environment, even though the consumer usually is not aware of all the relevant characteristics of this kind of product.

Carbon-carbon piston development

NASA Technical Reports Server (NTRS)

Gorton, Mark P.

1994-01-01

A new piston concept, made of carbon-carbon refractory-composite material, has been developed that overcomes a number of the shortcomings of aluminum pistons. Carbon-carbon material, developed in the early 1960's, is lighter in weight than aluminum, has higher strength and stiffness than aluminum and maintains these properties at temperatures over 2500 F. In addition, carbon-carbon material has a low coefficient of thermal expansion and excellent resistance to thermal shock. An effort, called the Advanced Carbon-Carbon Piston Program was started in 1986 to develop and test carbon-carbon pistons for use in spark ignition engines. The carbon-carbon pistons were designed to be replacements for existing aluminum pistons, using standard piston pin assemblies and using standard rings. Carbon-carbon pistons can potentially enable engines to be more reliable, more efficient and have greater power output. By utilizing the unique characteristics of carbon-carbon material a piston can: (1) have greater resistance to structural damage caused by overheating, lean air-fuel mixture conditions and detonation; (2) be designed to be lighter than an aluminum piston thus, reducing the reciprocating mass of an engine, and (3) be operated in a higher combustion temperature environment without failure.

Design of Bioinorganic Materials at the Interface of Coordination and Biosupramolecular Chemistry.

PubMed

Maity, Basudev; Ueno, Takafumi

2017-04-01

Protein assemblies have recently become known as potential molecular scaffolds for applications in materials science and bio-nanotechnology. Efforts to design protein assemblies for construction of protein-based hybrid materials with metal ions, metal complexes, nanomaterials and proteins now represent a growing field with a common aim of providing novel functions and mimicking natural functions. However, the important roles of protein assemblies in coordination and biosupramolecular chemistry have not been systematically investigated and characterized. In this personal account, we focus on our recent progress in rational design of protein assemblies using bioinorganic chemistry for (1) exploration of unnatural reactions, (2) construction of functional protein architectures, and (3) in vivo applications. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A manned-machine space station construction concept

NASA Technical Reports Server (NTRS)

Mikulas, M. M., Jr.; Bush, H. G.; Wallsom, R. E.; Dorsey, J. T.; Rhodes, M. D.

1984-01-01

A design concept for the construction of a permanent manned space station is developed and discussed. The main considerations examined in developing the design concept are: (1) the support structure of the station be stiff enough to preclude the need for an elaborate on-orbit system to control structural response, (2) the station support structure and solar power system be compatible with existing technology, and (3) the station be capable of growing in a systematic modular fashion. The concept is developed around the assembly of truss platforms by pressure-suited astronauts operating in extravehicular activity (EVA), assisted by a machine (Assembly and Transport Vehicle, ATV) to position the astronauts at joint locations where they latch truss members in place. The ATV is a mobile platform that is attached to and moves on the station support structure using pegs attached to each truss joint. The operation of the ATV is described and a number of conceptual configurations for potential space stations are developed.

New Layered Materials and Functional Nanoelectronic Devices

NASA Astrophysics Data System (ADS)

Yu, Jaeeun

This thesis introduces functional nanomaterials including superatoms and carbon nanotubes (CNTs) for new layered solids and molecular devices. Chapters 1-3 present how we incorporate superatoms into two-dimensional (2D) materials. Chapter 1 describes a new and simple approach to dope transition metal dichalcogenides (TMDCs) using the superatom Co6Se8(PEt3)6 as the electron dopant. Doping is an effective method to modulate the electrical properties of materials, and we demonstrate an electron-rich cluster can be used as a tunable and controllable surface dopant for semiconducting TMDCs via charge transfer. As a demonstration of the concept, we make a p-n junction by patterning on specific areas of TMDC films. Chapter 2 and Chapter 3 introduce new 2D materials by molecular design of superatoms. Traditional atomic van der Waals materials such as graphene, hexagonal boron-nitride, and TMDCs have received widespread attention due to the wealth of unusual physical and chemical behaviors that arise when charges, spins, and vibrations are confined to a plane. Though not as widespread as their atomic counterparts, molecule-based layered solids offer significant benefits; their structural flexibility will enable the development of materials with tunable properties. Chapter 2 describes a layered van der Waals solid self-assembled from a structure-directing building block and C60 fullerene. The resulting crystalline solid contains a corrugated monolayer of neutral fullerenes and can be mechanically exfoliated. Chapter 3 describes a new method to functionalize electroactive superatoms with groups that can direct their assembly into covalent and non-covalent multi-dimensional frameworks. We synthesized Co6Se8[PEt2(4-C6H4COOH)]6 and found that it forms two types of crystalline assemblies with Zn(NO3)2, one is a three-dimensional solid and the other consists of stacked layers of two-dimensional sheets. The dimensionality is controlled by subtle changes in reaction conditions. CNT-based field-effect transistor (FETs), in which a single molecule spans an oxidatively cut gap in the CNT, provide a versatile, ground-state platform with well-defined electrical contacts. For statistical studies of a variety of small molecule bridges, Chapter 4 presents a novel fabrication method to produce hundreds of FETs on one single carbon nanotube. A large number of devices allows us to study the stability and uniformity of CNT FET properties. Moreover, the new platform also enables a quantitative analysis of molecular devices. In particular, we used CNT FETs for studying DNA-mediated charge transport. DNA conductance was measured by connecting DNA molecules of varying lengths to lithographically cut CNT FETs.

Large-scale self-assembly of uniform submicron silver sulfide material driven by precise pressure control

NASA Astrophysics Data System (ADS)

Qi, Juanjuan; Chen, Ke; Zhang, Shuhao; Yang, Yun; Guo, Lin; Yang, Shihe

2017-03-01

The controllable self-assembly of nanosized building blocks into larger specific structures can provide an efficient method of synthesizing novel materials with excellent properties. The self-assembly of nanocrystals by assisted means is becoming an extremely active area of research, because it provides a method of producing large-scale advanced functional materials with potential applications in the areas of energy, electronics, optics, and biologics. In this study, we applied an efficient strategy, namely, the use of ‘pressure control’ to the assembly of silver sulfide (Ag2S) nanospheres with a diameter of approximately 33 nm into large-scale, uniform Ag2S sub-microspheres with a size of about 0.33 μm. More importantly, this strategy realizes the online control of the overall reaction system, including the pressure, reaction time, and temperature, and could also be used to easily fabricate other functional materials on an industrial scale. Moreover, the thermodynamics and kinetics parameters for the thermal decomposition of silver diethyldithiocarbamate (Ag(DDTC)) are also investigated to explore the formation mechanism of the Ag2S nanosized building blocks which can be assembled into uniform sub-micron scale architecture. As a method of producing sub-micron Ag2S particles by means of the pressure-controlled self-assembly of nanoparticles, we foresee this strategy being an efficient and universally applicable option for constructing other new building blocks and assembling novel and large functional micromaterials on an industrial scale.

A new family of omnidirectional and holonomic wheeled platforms for mobile robots

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

Pin, F.G.; Killough, S.M.

1994-08-01

This paper presents the concepts for a new family of holonomic wheeled platforms that feature full omnidirectionality with simultaneous and independently controlled rotational and translational motion capabilities. The authors first present the orthogonal-wheels'' concept and the two major wheel assemblies on which these platforms are based. The authors then describe how a combination of these assemblies with appropriate control can be used to generate an omnidirectional capability for mobile robot platforms. Several alternative designs are considered, and their respective characteristics with respect to rotational and translational motion control are discussed. The design and control of a prototype platform developed tomore » test and demonstrate the proposed concepts is then described, and experimental results illustrating the full omnidirectionality of the platforms with decoupled rotational and translational degrees of freedom are presented.« less

Development of a Thin-Film Solar Cell Interconnect for the Powersphere Concept

NASA Technical Reports Server (NTRS)

Simburger, Edward J.; Matsumoto, James H.; Giants, Thomas W.; Garcia, Alexander, III; Liu, Simon; Rawal, Suraj P.; Perry, Alan R.; Marshall, Craig; Lin, John K.; Scarborough, Stephen E.

2005-01-01

Dual junction amorphous silicon (a-Si) solar cells produced on polyimide substrate have been selected as the best candidate to produce a lightweight solar array for the PowerSphere program. The PowerSphere concept features a space-inflatable, geodetic solar array approximately 0.6 meters in diameter and capable of generating about 20W of electrical power. Trade studies of various wiring concepts and connection methods led to an interconnect design with a copper contact that wraps around the edge, to the back of the solar cell. Applying Plasma Vapor Deposited (PVD) copper film to both sides and the edge of the solar cell produces the wrap around contact. This procedure results in a contact pad on the back of the solar cell, which is then laser welded to a flex circuit material. The flex circuit is constructed of copper in a custom designed routing pattern, and then sandwiched in a Kapton insulation layer. The flex circuit then serves as the primary power distribution system between the solar cells and the spacecraft. Flex circuit material is the best candidate for the wiring harness because it allows for low force deployment of the solar cells by the inflatable hinges on the PowerSphere. An additional frame structure, fabricated and assembled by ILC Dover, will reinforce the wrap around contact-flex blanket connection, thus providing a mechanically robust solar cell interconnect for the PowerSphere multifunctional program. The PowerSphere team will use the wraparound contact design approach as the primary solution for solar cell integration and the flex blanket for power distribution.

Robustness analysis of non-ordinary Petri nets for flexible assembly/disassembly processes based on structural decomposition

NASA Astrophysics Data System (ADS)

Hsieh, Fu-Shiung

2011-03-01

Design of robust supervisory controllers for manufacturing systems with unreliable resources has received significant attention recently. Robustness analysis provides an alternative way to analyse a perturbed system to quickly respond to resource failures. Although we have analysed the robustness properties of several subclasses of ordinary Petri nets (PNs), analysis for non-ordinary PNs has not been done. Non-ordinary PNs have weighted arcs and have the advantage to compactly model operations requiring multiple parts or resources. In this article, we consider a class of flexible assembly/disassembly manufacturing systems and propose a non-ordinary flexible assembly/disassembly Petri net (NFADPN) model for this class of systems. As the class of flexible assembly/disassembly manufacturing systems can be regarded as the integration and interactions of a set of assembly/disassembly subprocesses, a bottom-up approach is adopted in this article to construct the NFADPN models. Due to the routing flexibility in NFADPN, there may exist different ways to accomplish the tasks. To characterise different ways to accomplish the tasks, we propose the concept of completely connected subprocesses. As long as there exists a set of completely connected subprocesses for certain type of products, the production of that type of products can still be maintained without requiring the whole NFADPN to be live. To take advantage of the alternative routes without enforcing liveness for the whole system, we generalise the concept of persistent production proposed to NFADPN. We propose a condition for persistent production based on the concept of completely connected subprocesses. We extend robustness analysis to NFADPN by exploiting its structure. We identify several patterns of resource failures and characterise the conditions to maintain operation in the presence of resource failures.

Self-assembly: Misfits unite

NASA Astrophysics Data System (ADS)

Grason, Gregory M.

2017-12-01

The spontaneous assembly of particulate or molecular 'building blocks' into larger architectures underlies structure formation in many biological and synthetic materials. Shape frustration of ill-fitting blocks holds a surprising key to more regular assemblies.

High-performance TiO(2) from Baker's yeast.

PubMed

He, Wen; Cui, Jingjie; Yue, Yuanzheng; Zhang, Xudong; Xia, Xi; Liu, Hong; Lui, Suwen

2011-02-01

Based on the biomineralization assembly concept, a biomimetic approach has been developed to synthesize high-performance mesoporous TiO(2). The key step of this approach is to apply Baker's yeast cells as biotemplates for deriving the hierarchically ordered mesoporous anatase structure. The mechanism of formation of the yeast-TiO(2) is revealed by characterizing its morphology, microstructure, and chemical composition. The yeast-TiO(2) exhibits outstanding photocatalytic performance. Under visible-light irradiation, the removal efficiency of chemical oxygen demand (COD) and color of the paper industry wastewater has reached 80.3% and nearly 100%, respectively. The approach may open new vistas for fabricating advanced mesoporous materials under ambient condition. Copyright © 2010 Elsevier Inc. All rights reserved.

Geckoprinting: assembly of microelectronic devices on unconventional surfaces by transfer printing with isolated gecko setal arrays

PubMed Central

Jeong, Jaeyoung; Kim, Juho; Song, Kwangsun; Autumn, Kellar; Lee, Jongho

2014-01-01

Developing electronics in unconventional forms provides opportunities to expand the use of electronics in diverse applications including bio-integrated or implanted electronics. One of the key challenges lies in integrating semiconductor microdevices onto unconventional substrates without glue, high pressure or temperature that may cause damage to microdevices, substrates or interfaces. This paper describes a solution based on natural gecko setal arrays that switch adhesion mechanically on and off, enabling pick and place manipulation of thin microscale semiconductor materials onto diverse surfaces including plants and insects whose surfaces are usually rough and irregular. A demonstration of functional ‘geckoprinted’ microelectronic devices provides a proof of concept of our results in practical applications. PMID:25056216

KWU's high conversion reactor concept - An economical evolution of modern pressurized water reactor technology toward improved uranium ore utilization

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

Markl, H.; Goetzmann, C.A.; Moldaschl, H.

The Kraftwerk Union AG high conversion reactor represents a quasi-standard PWR with fuel assemblies of more or less uniformly enriched fuel rods, arranged in a tight hexagonal array with a pitch-to-diameter ratio p/d approx. = 1.12. High fuel enrichment as well as a high conversion ratio of --0.9 will provide the potential for high burnup values up to 70 000 MWd/tonne and a low fissile material consumption. The overall objective of the actual RandD program is to have the technical feasibility, including that for licensibility, established by the early 1990s as a prerequisite for deciding whether to enter a demonstrationmore » plant program.« less

New Materials Based on Spider Silk

DTIC Science & Technology

2007-11-06

encoding the honey bee secretion signal was (genetically) fused to the spider silk protein. A respective recombinant virus was used to infect high...2007). Role of individual spider silk domains during assembly. Poster at the conference on "Protein Assembly in Materials, Biology and Medicine

Optical assembly of microparticles into highly ordered structures using Ince-Gaussian beams

NASA Astrophysics Data System (ADS)

Woerdemann, Mike; Alpmann, Christina; Denz, Cornelia

2011-03-01

Ince-Gaussian (IG) beams are a third complete family of solutions of the paraxial Helmholtz equation. While many applications of Hermite-Gaussian and Laguerre-Gaussian beams have been demonstrated for manipulation of microparticles, the potential of the more general class of IG beams has not yet been exploited at all. We describe the unique properties of IG beams with respect to optical trapping applications, demonstrate a flexible experimental realization of arbitrary IG beams and prove the concept by creating two- and three-dimensional, highly ordered assemblies of typical microparticles. The concept is universal and can easily be integrated into existing holographic optical tweezers setups.

Micro-masonry for 3D Additive Micromanufacturing

PubMed Central

Keum, Hohyun; Kim, Seok

2014-01-01

Transfer printing is a method to transfer solid micro/nanoscale materials (herein called ‘inks’) from a substrate where they are generated to a different substrate by utilizing elastomeric stamps. Transfer printing enables the integration of heterogeneous materials to fabricate unexampled structures or functional systems that are found in recent advanced devices such as flexible and stretchable solar cells and LED arrays. While transfer printing exhibits unique features in material assembly capability, the use of adhesive layers or the surface modification such as deposition of self-assembled monolayer (SAM) on substrates for enhancing printing processes hinders its wide adaptation in microassembly of microelectromechanical system (MEMS) structures and devices. To overcome this shortcoming, we developed an advanced mode of transfer printing which deterministically assembles individual microscale objects solely through controlling surface contact area without any surface alteration. The absence of an adhesive layer or other modification and the subsequent material bonding processes ensure not only mechanical bonding, but also thermal and electrical connection between assembled materials, which further opens various applications in adaptation in building unusual MEMS devices. PMID:25146178

An overview of the EASE/ACCESS space construction demonstration

NASA Technical Reports Server (NTRS)

Levin, George M.; Ross, Jerry L.; Spring, Sherwood C.

1988-01-01

Consideration is given to the development of the Experimental Assembly of Structures in EVA/Assembly Concept for Construction of Erectable Space Structures (EASE/ACCESS) space construction demonstration, which was performed during Space Shuttle mission 61-B. The mission equipment is described and illustrated and the EASE/ACCESS mission management structure is outlined. Simulations of the assembly and disassembly in the NASA neutral buoyancy simulators were used to test the mission plans. In addition, EVA training and crew performance for the mission are discussed.

One-dimensional poly(L-lysine)-block-poly(L-threonine) assemblies exhibit potent anticancer activity by enhancing membranolysis.

PubMed

Chen, Yu-Fon; Shiau, Ai-Li; Chang, Sue-Joan; Fan, Nai-Shin; Wang, Chung-Teng; Wu, Chao-Liang; Jan, Jeng-Shiung

2017-06-01

Herein, we report the oncolytic activity of cationic, one-dimensional (1D) fibril assemblies formed from coil-sheet poly(L-lysine)-block-poly(L-threonine) (PLL-b-PLT) block copolypeptides for cancer therapy. The 1D fibril assemblies can efficiently interact with negatively charged cellular and mitochondrial membranes via electrostatic interactions, leading to necrosis via membrane lysis and apoptosis via the mitochondria-lytic effect. The concept is analogous to that of 1D drug carriers that exhibit enhanced cell penetration. In comparison to free PLL chains, PLL-b-PLT fibril assemblies exhibit selective cytotoxicity toward cancer cells, low hemolysis activity, enhanced membranolytic activity, and a different apoptosis pathway, which may be due to differences in the peptide-membrane interactions. Antitumor studies using a metastatic LL2 lung carcinoma model indicate that the fibril assemblies significantly inhibited tumor growth, improved survival in tumor-bearing mice and suppressed lung metastasis without obvious body weight loss. An additive efficacy was also observed for treatment with both PLL-b-PLT and cisplatin. These results support the feasibility of using 1D fibril assemblies as potential apoptotic anticancer therapeutics. We report that cationic, one-dimensional (1D) fibril assemblies formed by coil-sheet poly(L-lysine)-block-poly(L-threonine) (PLL-b-PLT) block copolypeptides exhibited potent anticancer activity by enhancing membranolysis. The 1D fibril assemblies can efficiently interact with negatively charged cellular and mitochondrial membranes via electrostatic interactions, leading to necrosis via membrane lysis and apoptosis via mitochondria-lytic effect. Moreover, the fibril assemblies exhibited low hemolytic activity and selective cytotoxicity toward cancer cell, which is advantageous as compared to PLL and most antimicrobial/anticancerous peptides. This study provides a new concept of using cationic, 1D fibril assemblies for cancer therapy. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

78 FR 37785 - Foreign-Trade Zone (FTZ) 196-Fort Worth, Texas; Notification of Proposed Production Activity...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-24

... carrying cases, wrist straps, screws, power supplies, nickel/ cadmium batteries, lithium/ion batteries, other batteries, antenna assemblies, audio flex assemblies, bridge flex assemblies, interplex assembly... components and materials sourced from abroad include: labels, battery adhesives, decals, Kevlar protective...

Similarities and Differences in Teachers' and Researchers' Conceptions of Communicative Language Teaching: Does the Use of an Educational Model Cast a Better Light?

ERIC Educational Resources Information Center

Mangubhai, Francis; Marland, Perc; Dashwood, Ann; Son, Jeong-Bae

2005-01-01

This study seeks to document teachers' conceptions of communicative language teaching (CLT) and to compare their conceptions with a composite view of CLT assembled, in part, from researchers' accounts of the distinctive features of CLT. The research was prompted by a review of the relevant research literature showing that, though previous studies…

New Approach to Concept Feasibility and Design Studies for Astrophysics Missions

NASA Technical Reports Server (NTRS)

Deutsch, M. J.; McLaughlin, W.; Nichols, J.

1998-01-01

JPL has assembled a team of multidisciplinary experts with corporate knowledge of space mission and instrument development. The advanced Concept Design Team, known as Team X, provides interactive design trades including cost as a design parameter, and advanced visualization for pre-Phase A Studies.

Testing fundamental ecological concepts with a Pythium-Prunus pathosystem

USDA-ARS?s Scientific Manuscript database

The study of plant-pathogen interactions has enabled tests of basic ecological concepts on plant community assembly (Janzen-Connell Hypothesis) and plant invasion (Enemy Release Hypothesis). We used a field experiment to (#1) test whether Pythium effects depended on host (seedling) density and/or d...

Method of forming a ceramic to ceramic joint

DOEpatents

Cutler, Raymond Ashton; Hutchings, Kent Neal; Kleinlein, Brian Paul; Carolan, Michael Francis

2010-04-13

A method of joining at least two sintered bodies to form a composite structure, includes: providing a joint material between joining surfaces of first and second sintered bodies; applying pressure from 1 kP to less than 5 MPa to provide an assembly; heating the assembly to a conforming temperature sufficient to allow the joint material to conform to the joining surfaces; and further heating the assembly to a joining temperature below a minimum sintering temperature of the first and second sintered bodies. The joint material includes organic component(s) and ceramic particles. The ceramic particles constitute 40-75 vol. % of the joint material, and include at least one element of the first and/or second sintered bodies. Composite structures produced by the method are also disclosed.

Modeling the self-assembly of ordered nanoporous materials

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

Monson, Peter; Auerbach, Scott

This report describes progress on a collaborative project on the multiscale modeling of the assembly processes in the synthesis of nanoporous materials. Such materials are of enormous importance in modern technology with application in the chemical process industries, biomedicine and biotechnology as well as microelectronics. The project focuses on two important classes of materials: i) microporous crystalline materials, such as zeolites, and ii) ordered mesoporous materials. In the first case the pores are part of the crystalline structure, while in the second the structures are amorphous on the atomistic length scale but where surfactant templating gives rise to order onmore » the length scale of 2 - 20 nm. We have developed a modeling framework that encompasses both these kinds of materials. Our models focus on the assembly of corner sharing silica tetrahedra in the presence of structure directing agents. We emphasize a balance between sufficient realism in the models and computational tractibility given the complex many-body phenomena. We use both on-lattice and off-lattice models and the primary computational tools are Monte Carlo simulations with sampling techniques and ensembles appropriate to specific situations. Our modeling approach is the first to capture silica polymerization, nanopore crystallization, and mesopore formation through computer-simulated self assembly.« less

Biomimetic Hierarchical Assembly of Helical Supraparticles from Chiral Nanoparticles

DOE PAGES

Zhou, Yunlong; Marson, Ryan L.; van Anders, Greg; ...

2016-02-22

Chiroptical materials found in butterflies, beetles, stomatopod crustaceans, and other creatures are attributed to biocomposites with helical motifs and multiscale hierarchical organization. These structurally sophisticated materials self-assemble from primitive nanoscale building blocks, a process that is simpler and more energy efficient than many top-down methods currently used to produce similarly sized three-dimensional materials. In this paper, we report that molecular-scale chirality of a CdTe nanoparticle surface can be translated to nanoscale helical assemblies, leading to chiroptical activity in the visible electromagnetic range. Chiral CdTe nanoparticles coated with cysteine self-organize around Te cores to produce helical supraparticles. D-/L-Form of the aminomore » acid determines the dominant left/right helicity of the supraparticles. Coarse-grained molecular dynamics simulations with a helical pair-potential confirm the assembly mechanism and the origin of its enantioselectivity, providing a framework for engineering three-dimensional chiral materials by self-assembly. Finally, the helical supraparticles further self-organize into lamellar crystals with liquid crystalline order, demonstrating the possibility of hierarchical organization and with multiple structural motifs and length scales determined by molecular-scale asymmetry of nanoparticle interactions.« less

Method of forming and assembly of metal and ceramic parts

DOEpatents

Ripley, Edward B

2014-04-22

A method of forming and assembling at least two parts together that may be metal, ceramic, or a combination of metal and ceramic parts. Such parts may have different CTE. Individual parts that are formed and sintered from particles leave a network of interconnecting porosity in each sintered part. The separate parts are assembled together and then a fill material is infiltrated into the assembled parts using a method such as capillary action, gravity, and/or pressure. The assembly is then cured to yield a bonded and fully or near-fully dense part that has the desired physical and mechanical properties for the part's intended purpose. Structural strength may be added to the parts by the inclusion of fibrous materials.

Method of forming and assembly of metal parts and ceramic parts

DOEpatents

Ripley, Edward B [Knoxville, TN

2011-11-22

A method of forming and assembling at least two parts together that may be metal, ceramic, or a combination of metal and ceramic parts. Such parts may have different CTE. Individual parts that are formed and sintered from particles leave a network of interconnecting porosity in each sintered part. The separate parts are assembled together and then a fill material is infiltrated into the assembled parts using a method such as capillary action, gravity, and/or pressure. The assembly is then cured to yield a bonded and fully or near-fully dense part that has the desired physical and mechanical properties for the part's intended purpose. Structural strength may be added to the parts by the inclusion of fibrous materials.

Protein-only, antimicrobial peptide-containing recombinant nanoparticles with inherent built-in antibacterial activity.

PubMed

Serna, Naroa; Sánchez-García, Laura; Sánchez-Chardi, Alejandro; Unzueta, Ugutz; Roldán, Mónica; Mangues, Ramón; Vázquez, Esther; Villaverde, Antonio

2017-09-15

The emergence of bacterial antibiotic resistances is a serious concern in human and animal health. In this context, naturally occurring cationic antimicrobial peptides (AMPs) might play a main role in a next generation of drugs against bacterial infections. Taking an innovative approach to design self-organizing functional proteins, we have generated here protein-only nanoparticles with intrinsic AMP microbicide activity. Using a recombinant version of the GWH1 antimicrobial peptide as building block, these materials show a wide antibacterial activity spectrum in absence of detectable toxicity on mammalian cells. The GWH1-based nanoparticles combine clinically appealing properties of nanoscale materials with full biocompatibility, structural and functional plasticity and biological efficacy exhibited by proteins. Because of the largely implemented biological fabrication of recombinant protein drugs, the protein-based platform presented here represents a novel and scalable strategy in antimicrobial drug design, that by solving some of the limitations of AMPs offers a promising alternative to conventional antibiotics. The low molecular weight antimicrobial peptide GWH1 has been engineered to oligomerize as self-assembling protein-only nanoparticles of around 50nm. In this form, the peptide exhibits potent and broad antibacterial activities against both Gram-positive and Gram-negative bacteria, without any harmful effect over mammalian cells. As a solid proof-of-concept, this finding strongly supports the design and biofabrication of nanoscale antimicrobial materials with in-built functionalities. The protein-based homogeneous composition offer advantages over alternative materials explored as antimicrobial agents, regarding biocompatibility, biodegradability and environmental suitability. Beyond the described prototype, this transversal engineering concept has wide applicability in the design of novel nanomedicines for advanced treatments of bacterial infections. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Adaptive Semantic and Social Web-based learning and assessment environment for the STEM

NASA Astrophysics Data System (ADS)

Babaie, Hassan; Atchison, Chris; Sunderraman, Rajshekhar

2014-05-01

We are building a cloud- and Semantic Web-based personalized, adaptive learning environment for the STEM fields that integrates and leverages Social Web technologies to allow instructors and authors of learning material to collaborate in semi-automatic development and update of their common domain and task ontologies and building their learning resources. The semi-automatic ontology learning and development minimize issues related to the design and maintenance of domain ontologies by knowledge engineers who do not have any knowledge of the domain. The social web component of the personal adaptive system will allow individual and group learners to interact with each other and discuss their own learning experience and understanding of course material, and resolve issues related to their class assignments. The adaptive system will be capable of representing key knowledge concepts in different ways and difficulty levels based on learners' differences, and lead to different understanding of the same STEM content by different learners. It will adapt specific pedagogical strategies to individual learners based on their characteristics, cognition, and preferences, allow authors to assemble remotely accessed learning material into courses, and provide facilities for instructors to assess (in real time) the perception of students of course material, monitor their progress in the learning process, and generate timely feedback based on their understanding or misconceptions. The system applies a set of ontologies that structure the learning process, with multiple user friendly Web interfaces. These include the learning ontology (models learning objects, educational resources, and learning goal); context ontology (supports adaptive strategy by detecting student situation), domain ontology (structures concepts and context), learner ontology (models student profile, preferences, and behavior), task ontologies, technological ontology (defines devices and places that surround the student), pedagogy ontology, and learner ontology (defines time constraint, comment, profile).

Blast and Shock Mitigation Through the Use of Advanced Materials

NASA Astrophysics Data System (ADS)

Bartyczak, Susan; Edgerton, Lauren; Mock, Willis

2017-06-01

The dynamic response to low amplitude blast waves of four viscoelastic materials has been investigated: Dragonshield BCTM and three polyurea formulations (P1000, P650, and a P250/1000 blend). A 40-mm-bore gas gun was used as a shock tube to generate planar blast waves, ranging from 1 to 2 bars, that impacted instrumented target assemblies mounted on the gas gun muzzle. Each target assembly consisted of a viscoelastic material sample sandwiched between two gauge assemblies for measuring wave velocity and input/output stresses. Each gauge assembly consisted of one polyvinylidene fluoride (PVDF) stress gauge sandwiched between two 3.25 inch diameter 6061-T6 aluminum discs. Impedance matching techniques were used on the stress measurements to calculate the stresses on the front and back of the samples. The shock velocity-particle velocity relationship, stress-particle velocity relationship, and blast attenuation for each material were determined. The experimental technique, analysis methodology, and results will be presented.

Substituent Effects on the Self-Assembly/Coassembly and Hydrogelation of Phenylalanine Derivatives.

PubMed

Liyanage, Wathsala; Nilsson, Bradley L

2016-01-26

Supramolecular hydrogels derived from the self-assembly of organic molecules have been exploited for applications ranging from drug delivery to tissue engineering. The relationship between the structure of the assembly motif and the emergent properties of the resulting materials is often poorly understood, impeding rational approaches for the creation of next-generation materials. Aromatic π-π interactions play a significant role in the self-assembly of many supramolecular hydrogelators, but the exact nature of these interactions lacks definition. Conventional models that describe π-π interactions rely on quadrupolar electrostatic interactions between neighboring aryl groups in the π-system. However, recent experimental and computational studies reveal the potential importance of local dipolar interactions between elements of neighboring aromatic rings in stabilizing π-π interactions. Herein, we examine the nature of π-π interactions in the self- and coassembly of Fmoc-Phe-derived hydrogelators by systematically varying the electron-donating or electron-withdrawing nature of the side chain benzyl substituents and correlating these effects to the emergent assembly and gelation properties of the systems. These studies indicate a significant role for stabilizing dipolar interactions between neighboring benzyl groups in the assembled materials. Additional evidence for specific dipolar interactions is provided by high-resolution crystal structures obtained from dynamic transition of gel fibrils to crystals for several of the self-assembled/coassembled Fmoc-Phe derivatives. In addition to electronic effects, steric properties also have a significant effect on the interaction between neighboring benzyl groups in these assembled systems. These findings provide significant insight into the structure-function relationship for Fmoc-Phe-derived hydrogelators and give cues for the design of next-generation materials with desired emergent properties.

Creating Quasi Two-Dimensional Cluster-Assembled Materials through Self-Assembly of a Janus Polyoxometalate-Silsesquioxane Co-Cluster.

PubMed

Wu, Han; Zhang, Yu-Qi; Hu, Min-Biao; Ren, Li-Jun; Lin, Yue; Wang, Wei

2017-05-30

Clusters are an important class of nanoscale molecules or superatoms that exhibit an amazing diversity in structure, chemical composition, shape, and functionality. Assembling two types of clusters is creating emerging cluster-assembled materials (CAMs). In this paper, we report an effective approach to produce quasi two-dimensional (2D) CAMs of two types of spherelike clusters, polyhedral oligomeric silsesquioxanes (POSS), and polyoxometalates (POM). To avoid macrophase separation between the two clusters, they are covalently linked to form a POM-POSS cocluster with Janus characteristics and a dumbbell shape. This Janus characteristics enables the cocluster to self-assemble into diverse nanoaggregates, as conventional amphiphilic molecules and macromolecules do, in selective solvents. In our study, we obtained micelles, vesicles, nanosheets, and nanoribbons by tuning the n-hexane content in mixed solvents of acetone and n-hexane. Ordered packing of clusters in the nanosheets and nanoribbons were directly visualized using high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) technique. We infer that the increase of packing order results in the vesicle-to-sheet transition and the change in packing mode causes the sheet-to-ribbon transitions. Our findings have verified the effectivity of creating quasi 2D cluster-assembled materials though the cocluster self-assembly as a new approach to produce novel CAMs.

Self-assembly micro optical filter

NASA Astrophysics Data System (ADS)

Zhang, Ping (Cerina); Le, Kevin; Malalur-Nagaraja-Rao, Smitha; Hsu, Lun-Chen; Chiao, J.-C.

2006-01-01

Optical communication and sensor industry face critical challenges in manufacturing for system integration. Due to the assembly complexity and integration platform variety, micro optical components require costly alignment and assembly procedures, in which many required manual efforts. Consequently, self-assembly device architectures have become a great interest and could provide major advantages over the conventional optical devices. In this paper, we discussed a self-assembly integration platform for micro optical components. To demonstrate the adaptability and flexibility of the proposed optical device architectures, we chose a commercially available MEMS fabrication foundry service - MUMPs (Multi-User MEMS Process). In this work, polysilicon layers of MUMPS are used as the 3-D structural material for construction of micro component framework and actuators. However, because the polysilicon has high absorption in the visible and near infrared wavelength ranges, it is not suitable for optical interaction. To demonstrate the required optical performance, hybrid integration of materials was proposed and implemented. Organic compound materials were applied on the silicon-based framework to form the required optical interfaces. Organic compounds provide good optical transparency, flexibility to form filters or lens and inexpensive manufacturing procedures. In this paper, we have demonstrated a micro optical filter integrated with self-assembly structures. We will discuss the self-assembly mechanism, optical filter designs, fabrication issues and results.

Self-Assembly of Nanostructured Electronic Devices (454th Brookhaven Lecture)

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

Black, Charles

2009-12-16

Given suitable atmospheric conditions, water vapor from the air will crystallize into beautiful structures: snowflakes. Nature provides many other examples of spontaneous organization of materials into regular patterns, which is a process known as self-assembly. Since self-assembly works at all levels, it can be a useful tool for organizing materials on the nanometer scale. In particular, self-assembly provides a precise method for designing materials with improved electronic properties, thereby enabling advances in semiconductor electronics and solar devices. On Wednesday, December 16, at 4 p.m. in Berkner Hall, Charles Black of the Center for Functional Nanomaterials (CFN) will explore this topicmore » during the 454th Brookhaven Lecture, entitled “Self-Assembly of Nanostructured Electronic Devices.” Refreshments will be offered before and after the lecture. To attend this open-to-the-public event, visitors to the Lab ages 16 and older must present photo ID at the Main Gate. During this talk, Dr. Black will discuss examples of how self-assembly is being integrated into semiconductor microelectronics, as advances in the ability to define circuit elements at higher resolution have fueled more than 40 years of performance improvements. Self-assembly also promises advances in the performance of solar devices; thus he will describe his group’s recent results with nanostructured photovoltaic devices.« less

Collagen Self-Assembly on Orthopedic Magnesium Biomaterials Surface and Subsequent Bone Cell Attachment

PubMed Central

Zhao, Nan; Zhu, Donghui

2014-01-01

Magnesium (Mg) biomaterials are a new generation of biodegradable materials and have promising potential for orthopedic applications. After implantation in bone tissues, these materials will directly interact with extracellular matrix (ECM) biomolecules and bone cells. Type I collagen, the major component of bone ECM, forms the architecture scaffold that provides physical support for bone cell attachment. However, it is still unknown how Mg substrate affects collagen assembly on top of it as well as subsequent cell attachment and growth. Here, we studied the effects of collagen monomer concentration, pH, assembly time, and surface roughness of two Mg materials (pure Mg and AZ31) on collagen fibril formation. Results showed that formation of fibrils would not initiate until the monomer concentration reached a certain level depending on the type of Mg material. The thickness of collagen fibril increased with the increase of assembly time. The structures of collagen fibrils formed on semi-rough surfaces of Mg materials have a high similarity to that of native bone collagen. Next, cell attachment and growth after collagen assembly were examined. Materials with rough surface showed higher collagen adsorption but compromised bone cell attachment. Interestingly, surface roughness and collagen structure did not affect cell growth on AZ31 for up to a week. Findings from this work provide some insightful information on Mg-tissue interaction at the interface and guidance for future surface modifications of Mg biomaterials. PMID:25303459

Enzymatically Active Microgels from Self-Assembling Protein Nanofibrils for Microflow Chemistry

PubMed Central

2015-01-01

Amyloid fibrils represent a generic class of protein structure associated with both pathological states and with naturally occurring functional materials. This class of protein nanostructure has recently also emerged as an excellent foundation for sophisticated functional biocompatible materials including scaffolds and carriers for biologically active molecules. Protein-based materials offer the potential advantage that additional functions can be directly incorporated via gene fusion producing a single chimeric polypeptide that will both self-assemble and display the desired activity. To succeed, a chimeric protein system must self-assemble without the need for harsh triggering conditions which would damage the appended functional protein molecule. However, the micrometer to nanoscale patterning and morphological control of protein-based nanomaterials has remained challenging. This study demonstrates a general approach for overcoming these limitations through the microfluidic generation of enzymatically active microgels that are stabilized by amyloid nanofibrils. The use of scaffolds formed from biomaterials that self-assemble under mild conditions enables the formation of catalytic microgels while maintaining the integrity of the encapsulated enzyme. The enzymatically active microgel particles show robust material properties and their porous architecture allows diffusion in and out of reactants and products. In combination with microfluidic droplet trapping approaches, enzymatically active microgels illustrate the potential of self-assembling materials for enzyme immobilization and recycling, and for biological flow-chemistry. These design principles can be adopted to create countless other bioactive amyloid-based materials with diverse functions. PMID:26030507

A Method of Assembling Compact Coherent Fiber-Optic Bundles

NASA Technical Reports Server (NTRS)

Martin, Stefan; Liu, Duncan; Levine, Bruce Martin; Shao, Michael; Wallace, James

2007-01-01

A method of assembling coherent fiber-optic bundles in which all the fibers are packed together as closely as possible is undergoing development. The method is based, straightforwardly, on the established concept of hexagonal close packing; hence, the development efforts are focused on fixtures and techniques for practical implementation of hexagonal close packing of parallel optical fibers.

Computed Tomography Measuring Inside Machines

NASA Technical Reports Server (NTRS)

Wozniak, James F.; Scudder, Henry J.; Anders, Jeffrey E.

1995-01-01

Computed tomography applied to obtain approximate measurements of radial distances from centerline of turbopump to leading edges of diffuser vanes in turbopump. Use of computed tomography has significance beyond turbopump application: example of general concept of measuring internal dimensions of assembly of parts without having to perform time-consuming task of taking assembly apart and measuring internal parts on coordinate-measuring machine.

Third generation design solar cell module LSA task 5, large scale production

NASA Technical Reports Server (NTRS)

1980-01-01

A total of twelve (12) preproduction modules were constructed, tested, and delivered. A concept to the frame assembly was designed and proven to be quite reliable. This frame design, as well as the rest of the assembly, was designed with future high volume production and the use of automated equipment in mind.

Embracing Community Ecology in Plant Microbiome Research.

PubMed

Dini-Andreote, Francisco; Raaijmakers, Jos M

2018-06-01

Community assembly is mediated by selection, dispersal, drift, and speciation. Environmental selection is mostly used to date to explain patterns in plant microbiome assembly, whereas the influence of the other processes remains largely elusive. Recent studies highlight that adopting community ecology concepts provides a mechanistic framework for plant microbiome research. Copyright © 2018 Elsevier Ltd. All rights reserved.

Assembling in Sequence: A Saleable Work Skill. Occupation Simulation Packet. Grades 3rd-4th.

ERIC Educational Resources Information Center

Hueston, Jean

This teacher's guide for grades 3 and 4 contains simulated work experiences for students using the isolated skill concept - assembling in sequence. Teacher instructions include objectives, evaluation, and sequence of activities. The guide contains pre-tests and post-tests with instructions and answer keys. Three pre-skill activities are suggested,…

Scintillator assembly for alpha radiation detection and method of making the assembly

DOEpatents

McElhaney, Stephanie A.; Bauer, Martin L.; Chiles, Marion M.

1992-01-01

A scintillator assembly for use in the detection of alpha radiation includes a body of optically-transparent epoxy and an amount of phosphor particles embedded within the body adjacent one surface thereof. When making the body, the phosphor particles are mixed with the epoxy when in an uncured condition and permitted to settle to the bottom surface of a mold within which the epoxy/phosphor mixture is contained. When the mixture subsequently cures to form a hardened body, the one surface of the body which cured against the bottom surface of the mold is coated with a thin layer of opaque material for preventing ambient light form entering the body through the one surface. The layer of opaque material is thereafter coated with a layer of protective material to provide the assembly with a damage-resistant entrance window.

Free-floating dual-arm robots for space assembly

NASA Technical Reports Server (NTRS)

Agrawal, Sunil Kumar; Chen, M. Y.

1994-01-01

Freely moving systems in space conserve linear and angular momentum. As moving systems collide, the velocities get altered due to transfer of momentum. The development of strategies for assembly in a free-floating work environment requires a good understanding of primitives such as self motion of the robot, propulsion of the robot due to onboard thrusters, docking of the robot, retrieval of an object from a collection of objects, and release of an object in an object pool. The analytics of such assemblies involve not only kinematics and rigid body dynamics but also collision and impact dynamics of multibody systems. In an effort to understand such assemblies in zero gravity space environment, we are currently developing at Ohio University a free-floating assembly facility with a dual-arm planar robot equipped with thrusters, a free-floating material table, and a free-floating assembly table. The objective is to pick up workpieces from the material table and combine them into prespecified assemblies. This paper presents analytical models of assembly primitives and strategies for overall assembly. A computer simulation of an assembly is developed using the analytical models. The experiment facility will be used to verify the theoretical predictions.

Fire-resistant materials for aircraft passenger seat construction

NASA Technical Reports Server (NTRS)

Fewell, L. L.; Tesoro, G. C.; Moussa, A.; Kourtides, D. A.

1979-01-01

The thermal response characteristics of fabric and fabric-foam assemblies are described. The various aspects of the ignition behavior of contemporary aircraft passenger seat upholstery fabric materials relative to fabric materials made from thermally stable polymers are evaluated. The role of the polymeric foam backing on the thermal response of the fabric-foam assembly is also ascertained. The optimum utilization of improved fire-resistant fabric and foam materials in the construction of aircraft passenger seats is suggested.

Directed assembly of bio-inspired hierarchical materials with controlled nanofibrillar architectures

NASA Astrophysics Data System (ADS)

Tseng, Peter; Napier, Bradley; Zhao, Siwei; Mitropoulos, Alexander N.; Applegate, Matthew B.; Marelli, Benedetto; Kaplan, David L.; Omenetto, Fiorenzo G.

2017-05-01

In natural systems, directed self-assembly of structural proteins produces complex, hierarchical materials that exhibit a unique combination of mechanical, chemical and transport properties. This controlled process covers dimensions ranging from the nano- to the macroscale. Such materials are desirable to synthesize integrated and adaptive materials and systems. We describe a bio-inspired process to generate hierarchically defined structures with multiscale morphology by using regenerated silk fibroin. The combination of protein self-assembly and microscale mechanical constraints is used to form oriented, porous nanofibrillar networks within predesigned macroscopic structures. This approach allows us to predefine the mechanical and physical properties of these materials, achieved by the definition of gradients in nano- to macroscale order. We fabricate centimetre-scale material geometries including anchors, cables, lattices and webs, as well as functional materials with structure-dependent strength and anisotropic thermal transport. Finally, multiple three-dimensional geometries and doped nanofibrillar constructs are presented to illustrate the facile integration of synthetic and natural additives to form functional, interactive, hierarchical networks.

Engineered Living Materials: Prospects and Challenges for Using Biological Systems to Direct the Assembly of Smart Materials.

PubMed

Nguyen, Peter Q; Courchesne, Noémie-Manuelle Dorval; Duraj-Thatte, Anna; Praveschotinunt, Pichet; Joshi, Neel S

2018-05-01

Vast potential exists for the development of novel, engineered platforms that manipulate biology for the production of programmed advanced materials. Such systems would possess the autonomous, adaptive, and self-healing characteristics of living organisms, but would be engineered with the goal of assembling bulk materials with designer physicochemical or mechanical properties, across multiple length scales. Early efforts toward such engineered living materials (ELMs) are reviewed here, with an emphasis on engineered bacterial systems, living composite materials which integrate inorganic components, successful examples of large-scale implementation, and production methods. In addition, a conceptual exploration of the fundamental criteria of ELM technology and its future challenges is presented. Cradled within the rich intersection of synthetic biology and self-assembling materials, the development of ELM technologies allows the power of biology to be leveraged to grow complex structures and objects using a palette of bio-nanomaterials. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microassembly of Heterogeneous Materials using Transfer Printing and Thermal Processing

PubMed Central

Keum, Hohyun; Yang, Zining; Han, Kewen; Handler, Drew E.; Nguyen, Thong Nhu; Schutt-Aine, Jose; Bahl, Gaurav; Kim, Seok

2016-01-01

Enabling unique architectures and functionalities of microsystems for numerous applications in electronics, photonics and other areas often requires microassembly of separately prepared heterogeneous materials instead of monolithic microfabrication. However, microassembly of dissimilar materials while ensuring high structural integrity has been challenging in the context of deterministic transferring and joining of materials at the microscale where surface adhesion is far more dominant than body weight. Here we present an approach to assembling microsystems with microscale building blocks of four disparate classes of device-grade materials including semiconductors, metals, dielectrics, and polymers. This approach uniquely utilizes reversible adhesion-based transfer printing for material transferring and thermal processing for material joining at the microscale. The interfacial joining characteristics between materials assembled by this approach are systematically investigated upon different joining mechanisms using blister tests. The device level capabilities of this approach are further demonstrated through assembling and testing of a microtoroid resonator and a radio frequency (RF) microelectromechanical systems (MEMS) switch that involve optical and electrical functionalities with mechanical motion. This work opens up a unique route towards 3D heterogeneous material integration to fabricate microsystems. PMID:27427243

Micro/nano-particles and Cells: Manipulation, Transport, and Self-assembly

DTIC Science & Technology

2014-10-23

SECURITY CLASSIFICATION OF: Technologies that control nano- and micron- sized inert as well as biological materials are crucial to realizing engineered...that control nano- and micron- sized inert as well as biological materials are crucial to realizing engineered systems that can assemble, transport, and...nano-scale particles offer several advantages as building blocks of artificial materials . The relative ease of modifying their charge states

Printable nanostructured silicon solar cells for high-performance, large-area flexible photovoltaics.

PubMed

Lee, Sung-Min; Biswas, Roshni; Li, Weigu; Kang, Dongseok; Chan, Lesley; Yoon, Jongseung

2014-10-28

Nanostructured forms of crystalline silicon represent an attractive materials building block for photovoltaics due to their potential benefits to significantly reduce the consumption of active materials, relax the requirement of materials purity for high performance, and hence achieve greatly improved levelized cost of energy. Despite successful demonstrations for their concepts over the past decade, however, the practical application of nanostructured silicon solar cells for large-scale implementation has been hampered by many existing challenges associated with the consumption of the entire wafer or expensive source materials, difficulties to precisely control materials properties and doping characteristics, or restrictions on substrate materials and scalability. Here we present a highly integrable materials platform of nanostructured silicon solar cells that can overcome these limitations. Ultrathin silicon solar microcells integrated with engineered photonic nanostructures are fabricated directly from wafer-based source materials in configurations that can lower the materials cost and can be compatible with deterministic assembly procedures to allow programmable, large-scale distribution, unlimited choices of module substrates, as well as lightweight, mechanically compliant constructions. Systematic studies on optical and electrical properties, photovoltaic performance in experiments, as well as numerical modeling elucidate important design rules for nanoscale photon management with ultrathin, nanostructured silicon solar cells and their interconnected, mechanically flexible modules, where we demonstrate 12.4% solar-to-electric energy conversion efficiency for printed ultrathin (∼ 8 μm) nanostructured silicon solar cells when configured with near-optimal designs of rear-surface nanoposts, antireflection coating, and back-surface reflector.

Avengers Assemble! Using Pop-Culture Icons to Communicate Science

ERIC Educational Resources Information Center

Zehr, E. Paul

2014-01-01

Engaging communication of complex scientific concepts with the general public requires more than simplification. Compelling, relevant, and timely points of linkage between scientific concepts and the experiences and interests of the general public are needed. Pop-culture icons such as superheroes can represent excellent opportunities for exploring…