WorldWideScience

Sample records for aeronautical structural application

  1. Development of Structural Energy Storage for Aeronautics Applications

    Science.gov (United States)

    Santiago-Dejesus, Diana; Loyselle, Patricia L.; Demattia, Brianne; Bednarcyk, Brett; Olson, Erik; Smith, Russell; Hare, David

    2017-01-01

    The National Aeronautics and Space Administration (NASA) has identified Multifunctional Structures for High Efficiency Lightweight Load-bearing Storage (M-SHELLS) as critical to development of hybrid gas-electric propulsion for commercial aeronautical transport in the N+3 timeframe. The established goals include reducing emissions by 80 and fuel consumption by 60 from todays state of the art. The advancement will enable technology for NASA Aeronautics Research Mission Directorates (ARMD) Strategic Thrust 3 to pioneer big leaps in efficiency and environmental performance for ultra-efficient commercial transports, as well as Strategic Thrust 4 to pioneer low-carbon propulsion technology in the transition to that scheme. The M-SHELLS concept addresses the hybrid gas-electric highest risk with its primary objective: to save structures energy storage system weight for future commercial hybrid electric propulsion aircraft by melding the load-carrying structure with energy storage in a single material. NASA's multifunctional approach also combines supercapacitor and battery chemistries in a synergistic energy storage arrangement in tandem with supporting good mechanical properties. The arrangement provides an advantageous combination of specific power, energy, and strength.

  2. Aeronautical applications of high-temperature superconductors

    Science.gov (United States)

    Turney, George E.; Luidens, Roger W.; Uherka, Kenneth; Hull, John

    1989-01-01

    The successful development of high-temperature superconductors (HTS) could have a major impact on future aeronautical propulsion and aeronautical flight vehicle systems. A preliminary examination of the potential application of HTS for aeronautics indicates that significant benefits may be realized through the development and implementation of these newly discovered materials. Applications of high-temperature superconductors (currently substantiated at 95 k) were envisioned for several classes of aeronautical systems, including subsonic and supersonic transports, hypersonic aircraft, V/STOL aircraft, rotorcraft, and solar, microwave and laser powered aircraft. Introduced and described are the particular applications and potential benefits of high-temperature superconductors as related to aeronautics and/or aeronautical systems.

  3. Wireless Sensor Applications in Extreme Aeronautical Environments

    Science.gov (United States)

    Wilson, William C.; Atkinson, Gary M.

    2013-01-01

    NASA aeronautical programs require rigorous ground and flight testing. Many of the testing environments can be extremely harsh. These environments include cryogenic temperatures and high temperatures (greater than 1500 C). Temperature, pressure, vibration, ionizing radiation, and chemical exposure may all be part of the harsh environment found in testing. This paper presents a survey of research opportunities for universities and industry to develop new wireless sensors that address anticipated structural health monitoring (SHM) and testing needs for aeronautical vehicles. Potential applications of passive wireless sensors for ground testing and high altitude aircraft operations are presented. Some of the challenges and issues of the technology are also presented.

  4. TEXTILE STRUCTURES FOR AERONAUTICS (PART II

    Directory of Open Access Journals (Sweden)

    SOLER Miquel

    2014-05-01

    Full Text Available Three-dimensional (3D textile structures with better delamination resistance and damage impact tolerance to be applied in composites for structural components is one of the main goals of the aeronautical industry. Textile Research Centre in Canet de Mar has been working since 2008 in this field. Our staff has been designing, developing and producing different textile structures using different production methods and machinery to improve three-dimensional textile structures as fiber reinforcement for composites. This paper describes different tests done in our textile labs from unidirectional structures to woven, knitted or braided 3 D textile structures. Advantages and disadvantages of each textile structure are summarized. The second part of this paper deals with our know-how in the manufacturing and assessing of three-dimensional textile structures during this last five years in the field of textile structures for composites but also in the development of structures for other applications. In the field of composites for aeronautic sector we have developed textile structures using the main methods of textile production, that is to say, weaving, warp knitting, weft knitting and braiding. Comparing the advantages and disadvantages it could be said that braided fabrics, with a structure in the three space axes are the most suitable for fittings and frames.

  5. An ocean scatter propagation model for aeronautical satellite communication applications

    Science.gov (United States)

    Moreland, K. W.

    1990-01-01

    In this paper an ocean scattering propagation model, developed for aircraft-to-satellite (aeronautical) applications, is described. The purpose of the propagation model is to characterize the behavior of sea reflected multipath as a function of physical propagation path parameters. An accurate validation against the theoretical far field solution for a perfectly conducting sinusoidal surface is provided. Simulation results for typical L band aeronautical applications with low complexity antennas are presented.

  6. The application of artificial intelligence technology to aeronautical system design

    Science.gov (United States)

    Bouchard, E. E.; Kidwell, G. H.; Rogan, J. E.

    1988-01-01

    This paper describes the automation of one class of aeronautical design activity using artificial intelligence and advanced software techniques. Its purpose is to suggest concepts, terminology, and approaches that may be useful in enhancing design automation. By understanding the basic concepts and tasks in design, and the technologies that are available, it will be possible to produce, in the future, systems whose capabilities far exceed those of today's methods. Some of the tasks that will be discussed have already been automated and are in production use, resulting in significant productivity benefits. The concepts and techniques discussed are applicable to all design activity, though aeronautical applications are specifically presented.

  7. Approaches to simulate impact damages on aeronautical composite structures

    Science.gov (United States)

    Sanga, R. P. Lemanle; Garnier, C.; Pantalé, O.

    2018-02-01

    Impact damage is one of the most critical aggressions for composite structures in aeronautical applications. Consequences of a high/low velocity and high/low energy impacts are very important to investigate. It is usually admitted that the most critical configuration is the Barely Visible Impact Damage (BVID), with impact energy of about 25 J, where some internal damages, invisible on the impacted surface of the specimen, drastically reduce the residual properties of the impacted material. In this work we highlight by the finite element simulation, the damage initiation and propagation process and the size of the defaults created by low velocity impact. Two approaches were developed: the first one is the layup technic and the second one is based on the cohesive element technic. Both technics show the plies damages by the Hashin's criteria. Moreover the second one gives the delamination damages with regards to the Benzeggah-Kenane criteria. The validation of these models is done by confrontation with some experimental results.

  8. IPv6 Test Bed for Testing Aeronautical Applications

    Science.gov (United States)

    Wilkins, Ryan; Zernic, Michael; Dhas, Chris

    2004-01-01

    Aviation industries in United States and in Europe are undergoing a major paradigm shift in the introduction of new network technologies. In the US, NASA is also actively investigating the feasibility of IPv6 based networks for the aviation needs of the United States. In Europe, the Eurocontrol lead, Internet Protocol for Aviation Exchange (iPAX) Working Group is actively investigating the various ways of migrating the aviation authorities backbone infrastructure from X.25 based networks to an IPv6 based network. For the last 15 years, the global aviation community has pursued the development and implementation of an industry-specific set of communications standards known as the Aeronautical Telecommunications Network (ATN). These standards are now beginning to affect the emerging military Global Air Traffic Management (GATM) community as well as the commercial air transport community. Efforts are continuing to gain a full understanding of the differences and similarities between ATN and Internet architectures as related to Communications, Navigation, and Surveillance (CNS) infrastructure choices. This research paper describes the implementation of the IPv6 test bed at NASA GRC, and Computer Networks & Software, Inc. and these two test beds are interface to Eurocontrol over the IPv4 Internet. This research work looks into the possibility of providing QoS performance for Aviation application in an IPv6 network as is provided in an ATN based network. The test bed consists of three autonomous systems. The autonomous system represents CNS domain, NASA domain and a EUROCONTROL domain. The primary mode of connection between CNS IPv6 testbed and NASA and EUROCONTROL IPv6 testbed is initially a set of IPv6 over IPv4 tunnels. The aviation application under test (CPDLC) consists of two processes running on different IPv6 enabled machines.

  9. Development of a 3-D model for eddy current testing: application for fastened structures in aeronautics; Developpement d'un modele pour le controle non destructif par courants de Foucault de structures rivetees en aeronautique

    Energy Technology Data Exchange (ETDEWEB)

    Paillard, S

    2007-12-15

    One of the Eddy Current Testing issues in aeronautics is the inspection of fastened structures to detect flaws nearby rivets which can grow because of mechanical stress. EADS and the CEA LIST have started a collaborative work with the support of the Ile-de-France Region to develop a simulation tool of EC fastened structures testing, integrated to the CIVA platform, aimed at conceiving testing methods, optimizing and qualifying it. The volume integral method using the Green dyadics formalism has been chosen in order to get a fast resolution of Maxwell equations. A first milestone was to build a simulation model of multilayer structures testing, thanks to the use of the multilayer Green dyads. Because of the rivet volume, 60 times bigger than the one of a typical flaw, a large number of discretization cells are needed. Therefore an iterative method has been developed in order to numerically solve large calculation zones. Finally, the flaw response simulation mostly has to cope with a scale issue between the size of the rivet and the one of the flaw, the latter being much smaller in a direction than the former. The whole model has been experimentally validated and compared to other simulation models at the important development steps: multilayer configuration, iteration resolution, and flaw signature. (author)

  10. Quick fabrication of aeronautical complicated structural parts based on stereolithography

    Directory of Open Access Journals (Sweden)

    Jiangping Zhou

    2015-06-01

    Full Text Available Investment casting based on stereolithography (SL has the characteristics of short production cycle and low cost, which is especially suitable for fabricating complex aeronautical parts without metal dies. But there are some problems during the fabrication process, such as low surface accuracy caused by the staircases of resin prototype, shell cracking caused by higher thermal stress during the sintering process and so on. Taking an engine turbine stator as a fabrication example, the surface accuracy of resin prototype under the effect of coating method was investigated using the laser confocal microscopy; what’s more, both theoretical analysis and finite element analysis (FEA were combined and compared to reveal the thermal stress field of ceramic shell during pyrolyzing and sintering process under different situation. It was founded that the surface staircases of the resin prototype was eliminated and the surface quality was improved after coating process, the thermal stress was decreased and shell cracking was avoided by sintering the ceramic shell with the inner hollow resin prototype under the heating rate of 5 °C/min. The result showed that, the metal turbine stator had high dimensional accuracy of CT4-CT6 and had a good surface finish within Ra 3.2.

  11. PEMFC for aeronautic applications: A review on the durability aspects

    Science.gov (United States)

    Dyantyi, Noluntu; Parsons, Adrian; Sita, Cordellia; Pasupathi, Sivakumar

    2017-11-01

    Proton exchange membrane fuel cells (PEMFC) not only offer more efficient electrical energy conversion, relative to on-ground/backup turbines but generate by-products useful in aircraft such as heat for ice prevention, deoxygenated air for fire retardation and drinkable water for use on-board. Consequently, several projects (e.g. DLR-H2 Antares and RAPID2000) have successfully tested PEMFC-powered auxiliary unit (APU) for manned/unmanned aircraft. Despite the progress from flying PEMFC-powered small aircraft with 20 kW power output as high as 1 000 m at 100 km/h to 33 kW at 2 558 m, 176 km/h [1, 2, 3], durability and reliability remain key challenges. This review reports on the inadequate understanding of behaviour of PEMFC under aeronautic conditions and the lack of predictive methods conducive for aircraft that provide real-time information on the State of Health of PEMFCs. -To minimize performance loss due to high altitude and inclination by adjusting cathode stoichiometric ratio. -To improve quality of oxygen-depleted air by controlling operating temperature and stoichiometric ratio. -Need to devise real time prediction methods conducive for determining PEMFC SoH in aircraft.

  12. A Reconfigurable Transmitter and Receiver for Aeronautical Telemetry Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This project focuses on the development of a reconfigurable microwave transmitter and receiver for telemetry applications. Both the transmitter and receiver are able...

  13. Control of Energy Storage Systems for Aeronautic Applications

    Directory of Open Access Journals (Sweden)

    G. Canciello

    2017-01-01

    Full Text Available Future aircraft will make more and more use of automated electric power system management onboard. Different solutions are currently being explored, and in particular the use of a supercapacitor as an intelligent energy storage device is addressed in this paper. The main task of the supercapacitor is to protect the electric generator from abrupt power changes resulting from sudden insertion or disconnection of loads or from loads with regenerative power capabilities, like electromagnetic actuators. A controller based on high-gain concepts is designed to drive a DC/DC converter connecting the supercapacitor to the main electric bus. Formal stability proofs are given for the resulting nonlinear system, and strong robustness results from the use of high-gain and variable structure control implementation. Moreover, detailed simulations including switching devices and electrical parasitic elements are provided for different working scenarios, showing the effectiveness of the proposed solution.

  14. Effects of Novel Structure Bonding Materials on Properties of Aeronautical Acrylic

    Directory of Open Access Journals (Sweden)

    LI Zhisheng

    2017-06-01

    Full Text Available Novel structure bonding materials, J-351 epoxy adhesive film with low curing temperature and liquid modified acrylate SY-50s adhesive were chosen and characterized. The effects of adhesives on the mechanical properties of acrylic were studied. The results reveal that both adhesives have excellent bonding properties to acrylic. The stress-solvent crazing value of J-351 is higher than that of SY-50s. With the application of adhesive on the surface, mechanical properties of acrylic are declined. Casting acrylic shows more drastic decline than that of oriented acrylic. Through the characterization of fracture surface, we find that fracture of tensile sample derives from the side with adhesive. Mechanical properties of acrylic are more sensitive to SY-50s, because the liquid adhesive presents integrate bonding interface with acrylic. The interface between J-351 and acrylic is clear, making acrylic insensitive to J-351 film. Edge attachment strength of samples bonded with J-351 are higher than that of samples bonded with SY-50s due to the effects of adhesives on acrylic. J-351 epoxy adhesive film presents preferable application performance in the structure bonding of aeronautical acrylic.

  15. Graphene-Based Filters and Supercapacitors for Space and Aeronautical Applications

    Science.gov (United States)

    Calle, Carlos I.

    2015-01-01

    Overview of the capabilities of graphene for selective filters and for energy storage with a general description of the work being done at NASA Kennedy Space Center in collaboration with the University of California Los Angeles for space and aeronautical applications.

  16. An application of characteristic function in order to predict reliability and lifetime of aeronautical hardware

    International Nuclear Information System (INIS)

    Żurek, Józef; Kaleta, Ryszard; Zieja, Mariusz

    2016-01-01

    The forecasting of reliability and life of aeronautical hardware requires recognition of many and various destructive processes that deteriorate the health/maintenance status thereof. The aging of technical components of aircraft as an armament system proves of outstanding significance to reliability and safety of the whole system. The aging process is usually induced by many and various factors, just to mention mechanical, biological, climatic, or chemical ones. The aging is an irreversible process and considerably affects (i.e. reduces) reliability and lifetime of aeronautical equipment. Application of the characteristic function of the aging process is suggested to predict reliability and lifetime of aeronautical hardware. An increment in values of diagnostic parameters is introduced to formulate then, using the characteristic function and after some rearrangements, the partial differential equation. An analytical dependence for the characteristic function of the aging process is a solution to this equation. With the inverse transformation applied, the density function of the aging of aeronautical hardware is found. Having found the density function, one can determine the aeronautical equipment’s reliability and lifetime. The in-service collected or the life tests delivered data are used to attain this goal. Coefficients in this relationship are found using the likelihood function.

  17. Global mobile satellite communications theory for maritime, land and aeronautical applications

    CERN Document Server

    Ilčev, Stojče Dimov

    2017-01-01

    This book discusses current theory regarding global mobile satellite communications (GMSC) for maritime, land (road and rail), and aeronautical applications. It covers how these can enable connections between moving objects such as ships, road and rail vehicles and aircrafts on one hand, and on the other ground telecommunications subscribers through the medium of communications satellites, ground earth stations, Terrestrial Telecommunication Networks (TTN), Internet Service Providers (ISP) and other wireless and landline telecommunications providers. This new edition covers new developments and initiatives that have resulted in land and aeronautical applications and the introduction of new satellite constellations in non-geostationary orbits and projects of new hybrid satellite constellations. The book presents current GMSC trends, mobile system concepts and network architecture using a simple mode of style with understandable technical information, characteristics, graphics, illustrations and mathematics equ...

  18. The impact of active controls technology on the structural integrity of aeronautical vehicles

    Science.gov (United States)

    Noll, Thomas E.; Austin, Edward; Donley, Shawn; Graham, George; Harris, Terry; Kaynes, Ian; Lee, Ben; Sparrow, James

    1993-01-01

    The findings of an investigation conducted under the auspices of The Technical Cooperation Program (TTCP) to assess the impact of active controls technology on the structural integrity of aeronautical vehicles and to evaluate the present state-of-the-art for predicting loads caused by a flight-control system modification and the resulting change in the fatigue life of the flight vehicle are summarized. Important points concerning structural technology considerations implicit in applying active controls technology in new aircraft are summarized. These points are well founded and based upon information received from within the aerospace industry and government laboratories, acquired by sponsoring workshops which brought together experts from contributing and interacting technical disciplines, and obtained by conducting a case study to independently assess the state of the technology. The paper concludes that communication between technical disciplines is absolutely essential in the design of future high performance aircraft.

  19. Sandwich Structured Composites for Aeronautics: Methods of Manufacturing Affecting Some Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Aneta Krzyżak

    2016-01-01

    Full Text Available Sandwich panels are composites which consist of two thin laminate outer skins and lightweight (e.g., honeycomb thick core structure. Owing to the core structure, such composites are distinguished by stiffness. Despite the thickness of the core, sandwich composites are light and have a relatively high flexural strength. These composites have a spatial structure, which affects good thermal insulator properties. Sandwich panels are used in aeronautics, road vehicles, ships, and civil engineering. The mechanical properties of these composites are directly dependent on the properties of sandwich components and method of manufacturing. The paper presents some aspects of technology and its influence on mechanical properties of sandwich structure polymer composites. The sandwiches described in the paper were made by three different methods: hand lay-up, press method, and autoclave use. The samples of sandwiches were tested for failure caused by impact load. Sandwiches prepared in the same way were used for structural analysis of adhesive layer between panels and core. The results of research showed that the method of manufacturing, more precisely the pressure while forming sandwich panels, influences some mechanical properties of sandwich structured polymer composites such as flexural strength, impact strength, and compressive strength.

  20. Survivability of integrated PVDF film sensors to accelerated ageing conditions in aeronautical/aerospace structures

    Science.gov (United States)

    Guzman, E.; Cugnoni, J.; Gmür, T.; Bonhôte, P.; Schorderet, A.

    2013-06-01

    This work validates the use of integrated polyvinylidene fluoride (PVDF) film sensors for dynamic testing, even after being subjected to UV-thermo-hygro-mechanical accelerated ageing conditions. The verification of PVDF sensors’ survivability in these environmental conditions, typically confronted by civil and military aircraft, is the main concern of the study. The evaluation of survivability is made by a comparison of dynamic testing results provided by the PVDF patch sensors subjected to an accelerated ageing protocol, and those provided by neutral non-aged sensors (accelerometers). The available measurements are the time-domain response signals issued from a modal analysis procedure, and the corresponding frequency response functions (FRF). These are in turn used to identify the constitutive properties of the samples by extraction of the modal parameters, in particular the natural frequencies. The composite specimens in this study undergo different accelerated ageing processes. After several weeks of experimentation, the samples exhibit a loss of stiffness, represented by a decrease in the elastic moduli down to 10%. Despite the ageing, the integrated PVDF sensors, subjected to the same ageing conditions, are still capable of providing reliable data to carry out a close followup of these changes. This survivability is a determinant asset in order to use integrated PVDF sensors to perform structural health monitoring (SHM) in the future of full-scale composite aeronautical structures.

  1. Progress in aeronautical research and technology applicable to civil air transports

    Science.gov (United States)

    Bower, R. E.

    1981-01-01

    Recent progress in the aeronautical research and technology program being conducted by the United States National Aeronautics and Space Administration is discussed. Emphasis is on computational capability, new testing facilities, drag reduction, turbofan and turboprop propulsion, noise, composite materials, active controls, integrated avionics, cockpit displays, flight management, and operating problems. It is shown that this technology is significantly impacting the efficiency of the new civil air transports. The excitement of emerging research promises even greater benefits to future aircraft developments.

  2. Flammability limits: A review with emphasis on ethanol for aeronautical applications and description of the experimental procedure

    International Nuclear Information System (INIS)

    Coronado, Christian J.R.; Carvalho, João A.; Andrade, José C.; Cortez, Ely V.; Carvalho, Felipe S.; Santos, José C.; Mendiburu, Andrés Z.

    2012-01-01

    Highlights: ► Develops a comprehensive literature review on ethanol flammability limits. ► Difference in standard procedures lead to different experimental values of the flammability limits. ► Methodology for experiments to find the FL's of ethanol for aeronautical applications. - Abstract: The lower and upper flammability limits of a fuel are key tools for predicting fire, assessing the possibility of explosion, and designing protection systems. Knowledge about the risks involved with the explosion of both gaseous and vaporized liquid fuel mixtures with air is very important to guarantee safety in industrial, domestic, and aeronautical applications. Currently, most countries use various standard experimental tests, which lead to different experimental values for these limits. A comprehensive literature review of the flammability limits of combustible mixtures is developed here in order to organize the theoretical and practical knowledge of the subject. The main focus of this paper is the review of the flammability data of ethanol–air mixtures available in the literature. In addition, the description of methodology for experiments to find the upper and lower limits of flammability of ethanol for aeronautical applications is discussed. A heated spherical 20 L vessel was used. The mixtures were ignited with electrode rods placed in the center of the vessel, and the spark gap was 6.4 mm. LFL and the UFL were determined for ethanol (hydrated ethanol 96% °INPM) as functions of temperature for atmospheric pressure to compare results with data published in the scientific literature.

  3. Flammability limits: A review with emphasis on ethanol for aeronautical applications and description of the experimental procedure

    Energy Technology Data Exchange (ETDEWEB)

    Coronado, Christian J.R. [Federal University of Itajuba - UNIFEI, Mechanical Engineering Institute - IEM Av BPS 1303, Itajuba, MG CEP 37500903 (Brazil); Carvalho, Joao A., E-mail: joao@feg.unesp.br [Sao Paulo State University - UNESP, Campus of Guaratingueta - FEG Av. Ariberto P. da Cunha 333, Guaratingueta, SP CEP 12510410 (Brazil); Andrade, Jose C.; Cortez, Ely V. [National Space Research Institute - INPE, Combustion and Propulsion Laboratory - LCP Rod. Pres. Dutra, km 39, Cachoeira Paulista, SP CEP 12630-000 (Brazil); Carvalho, Felipe S. [Federal University of Itajuba - UNIFEI, Mechanical Engineering Institute - IEM Av BPS 1303, Itajuba, MG CEP 37500903 (Brazil); Santos, Jose C. [National Space Research Institute - INPE, Combustion and Propulsion Laboratory - LCP Rod. Pres. Dutra, km 39, Cachoeira Paulista, SP CEP 12630-000 (Brazil); Mendiburu, Andres Z. [Sao Paulo State University - UNESP, Campus of Guaratingueta - FEG Av. Ariberto P. da Cunha 333, Guaratingueta, SP CEP 12510410 (Brazil)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer Develops a comprehensive literature review on ethanol flammability limits. Black-Right-Pointing-Pointer Difference in standard procedures lead to different experimental values of the flammability limits. Black-Right-Pointing-Pointer Methodology for experiments to find the FL's of ethanol for aeronautical applications. - Abstract: The lower and upper flammability limits of a fuel are key tools for predicting fire, assessing the possibility of explosion, and designing protection systems. Knowledge about the risks involved with the explosion of both gaseous and vaporized liquid fuel mixtures with air is very important to guarantee safety in industrial, domestic, and aeronautical applications. Currently, most countries use various standard experimental tests, which lead to different experimental values for these limits. A comprehensive literature review of the flammability limits of combustible mixtures is developed here in order to organize the theoretical and practical knowledge of the subject. The main focus of this paper is the review of the flammability data of ethanol-air mixtures available in the literature. In addition, the description of methodology for experiments to find the upper and lower limits of flammability of ethanol for aeronautical applications is discussed. A heated spherical 20 L vessel was used. The mixtures were ignited with electrode rods placed in the center of the vessel, and the spark gap was 6.4 mm. LFL and the UFL were determined for ethanol (hydrated ethanol 96% Degree-Sign INPM) as functions of temperature for atmospheric pressure to compare results with data published in the scientific literature.

  4. The National Aeronautics and Space Administration's Earth Science Applications Program: Exploring Partnerships to Enhance Decision Making in Public Health Practice

    Science.gov (United States)

    Vann, Timi S.; Venezia, Robert A.

    2002-01-01

    The National Aeronautics and Space Administration (NASA), Earth Science Enterprise is engaged in applications of NASA Earth science and remote sensing technologies for public health. Efforts are focused on establishing partnerships with those agencies and organizations that have responsibility for protecting the Nation's Health. The program's goal is the integration of NASA's advanced data and technology for enhanced decision support in the areas of disease surveillance and environmental health. A focused applications program, based on understanding partner issues and requirements, has the potential to significantly contribute to more informed decision making in public health practice. This paper intends to provide background information on NASA's investment in public health and is a call for partnership with the larger practice community.

  5. Essentials of fluid dynamics with applications to hydraulics, aeronautics, meteorology and other subjets

    CERN Document Server

    Prandtl, Ludwig

    1953-01-01

    Equilibrium of liquids and gases ; kinematics : dynamics of frictionless fluids ; motion of viscous fluids : turbulence : fluid resistance : practical applications ; flow with appreciable volume changes (dynamics of gases) ; miscellaneous topics.

  6. Evolutionary optimization and game strategies for advanced multi-disciplinary design applications to aeronautics and UAV design

    CERN Document Server

    Periaux, Jacques; Lee, Dong Seop Chris

    2015-01-01

    Many complex aeronautical design problems can be formulated with efficient multi-objective evolutionary optimization methods and game strategies. This book describes the role of advanced innovative evolution tools in the solution, or the set of solutions of single or multi disciplinary optimization. These tools use the concept of multi-population, asynchronous parallelization and hierarchical topology which allows different models including precise, intermediate and approximate models with each node belonging to the different hierarchical layer handled by a different Evolutionary Algorithm. The efficiency of evolutionary algorithms for both single and multi-objective optimization problems are significantly improved by the coupling of EAs with games and in particular by a new dynamic methodology named “Hybridized Nash-Pareto games”. Multi objective Optimization techniques and robust design problems taking into account uncertainties are introduced and explained in detail. Several applications dealing with c...

  7. Technical features and criteria in designing fiber-reinforced composite materials: from the aerospace and aeronautical field to biomedical applications.

    Science.gov (United States)

    Gloria, Antonio; Ronca, Dante; Russo, Teresa; D'Amora, Ugo; Chierchia, Marianna; De Santis, Roberto; Nicolais, Luigi; Ambrosio, Luigi

    2011-01-01

    Polymer-based composite materials are ideal for applications where high stiffness-to-weight and strength-to-weight ratios are required. From aerospace and aeronautical field to biomedical applications, fiber-reinforced polymers have replaced metals, thus emerging as an interesting alternative. As widely reported, the mechanical behavior of the composite materials involves investigation on micro- and macro-scale, taking into consideration micromechanics, macromechanics and lamination theory. Clinical situations often require repairing connective tissues and the use of composite materials may be suitable for these applications because of the possibility to design tissue substitutes or implants with the required mechanical properties. Accordingly, this review aims at stressing the importance of fiber-reinforced composite materials to make advanced and biomimetic prostheses with tailored mechanical properties, starting from the basic principle design, technologies, and a brief overview of composites applications in several fields. Fiber-reinforced composite materials for artificial tendons, ligaments, and intervertebral discs, as well as for hip stems and mandible models will be reviewed, highlighting the possibility to mimic the mechanical properties of the soft and hard tissues that they replace.

  8. Solid Lubrication by Multiwalled Carbon Nanotubes in Air and in Vacuum for Space and Aeronautics Applications

    Science.gov (United States)

    Miyoshi, Kazuhisa; Street, Kenneth W., Jr.; Andraws, Rodney; Jacques, David; VanderWal, Randy L.; Sayir, Ali

    2005-01-01

    To evaluate recently developed aligned multiwalled carbon nanotubes (MWNTs) and dispersed MWNTs for solid lubrication applications, unidirectional sliding friction experiments were conducted with 440 C stainless steel balls and hemispherical alumina-yttria stabilized zirconia pins in sliding contact with the MWNTs deposited on quartz disks in air and in vacuum. The results indicate that MWNTs have superior solid lubrication friction properties and endurance lives in air and vacuum under dry conditions. The coefficient of friction of the dispersed MWNTs is close to 0.05 and 0.009 in air and in vacuum, respectively, showing good dry lubricating ability. The wear life of MWNTs exceeds 1 million passes in both air and vacuum showing good durability. In general, the low coefficient of friction can be attributed to the combination of the transferred, agglomerated patches of MWNTs on the counterpart ball or pin surfaces and the presence of tubular MWNTs at interfaces.

  9. 14 CFR 61.185 - Aeronautical knowledge.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical knowledge. 61.185 Section 61... Flight Instructors With a Sport Pilot Rating § 61.185 Aeronautical knowledge. (a) A person who is... aeronautical knowledge areas for a recreational, private, and commercial pilot certificate applicable to the...

  10. Aeronautical Information System -

    Data.gov (United States)

    Department of Transportation — The Aeronautical Information System (AIS) is a leased weather automated system that provides a means of collecting and distributing aeronautical weather information...

  11. Nanotube MMC for structural applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Aluminum based metal matrix composites are particularly attractive in aviation and aerospace applications because of their exceptional strength and...

  12. Nanotube MMC for Structural Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aluminum based metal matrix composites are particularly attractive in aviation and aerospace applications because of their exceptional strength and...

  13. Convergent Aeronautics Solutions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Convergent Aeronautics Solutions (CAS) Project uses short-duration activities to establish early-stage concept and technology feasibility for high-potential...

  14. Aeronautical Information System Replacement -

    Data.gov (United States)

    Department of Transportation — Aeronautical Information System Replacement is a web-enabled, automation means for the collection and distribution of Service B messages, weather information, flight...

  15. Dryden Aeronautical Test Range

    Data.gov (United States)

    Federal Laboratory Consortium — Recently redesignated to honor Dr. Hugh L. Dryden, NASA's Dryden Aeronautical Test Range (DATR) supports aerospace flight research and technology integration, space...

  16. Research and technology developments in aeronautics, atmospheric and oceanographic measurements, radar applications, and remote sensing of insects using radar

    Science.gov (United States)

    Oberholtzer, J. D. (Editor)

    1980-01-01

    Highlights of the year's activities and accomplishments are reported in the areas of aircraft safety, scientific ballooning, mid-air payload retrieval, and the design of a microwave power reception and conversion system for on use on a high altitude powered platform. The development and application of an agro-environmental system to provide crop management advisory information to Virginia farmers, and the radar tracking of insects are described. Aircraft systems, developed for measuring atmospheric ozone and nitric acid were used to sample emissions from Mount St. Helens. Investigations of the reliability and precision of the U.S. standard meteorological rocketsonde, applications of the microwave altimeter and airborne lidar system in oceanography, and the development of a multibeam altimeter concept are also summarized.

  17. Man-Machine Integration Design and Analysis System (MIDAS) v5: Augmentations, Motivations, and Directions for Aeronautics Applications

    Science.gov (United States)

    Gore, Brian F.

    2011-01-01

    As automation and advanced technologies are introduced into transport systems ranging from the Next Generation Air Transportation System termed NextGen, to the advanced surface transportation systems as exemplified by the Intelligent Transportations Systems, to future systems designed for space exploration, there is an increased need to validly predict how the future systems will be vulnerable to error given the demands imposed by the assistive technologies. One formalized approach to study the impact of assistive technologies on the human operator in a safe and non-obtrusive manner is through the use of human performance models (HPMs). HPMs play an integral role when complex human-system designs are proposed, developed, and tested. One HPM tool termed the Man-machine Integration Design and Analysis System (MIDAS) is a NASA Ames Research Center HPM software tool that has been applied to predict human-system performance in various domains since 1986. MIDAS is a dynamic, integrated HPM and simulation environment that facilitates the design, visualization, and computational evaluation of complex man-machine system concepts in simulated operational environments. The paper will discuss a range of aviation specific applications including an approach used to model human error for NASA s Aviation Safety Program, and what-if analyses to evaluate flight deck technologies for NextGen operations. This chapter will culminate by raising two challenges for the field of predictive HPMs for complex human-system designs that evaluate assistive technologies: that of (1) model transparency and (2) model validation.

  18. Modeling, fabrication and plasma actuator coupling of flexible pressure sensors for flow separation detection and control in aeronautical applications

    International Nuclear Information System (INIS)

    Francioso, L; De Pascali, C; Siciliano, P; Pescini, E; De Giorgi, M G

    2016-01-01

    Preventing the flow separation could enhance the performance of propulsion systems and future civil aircraft. To this end, a fast detection of boundary layer separation is mandatory for a sustainable and successful application of active flow control devices, such as plasma actuators. The present work reports on the design, fabrication and functional tests of low-cost capacitive pressure sensors coupled with dielectric barrier discharge (DBD) plasma actuators to detect and then control flow separation. Finite element method (FEM) simulations were used to obtain information on the deflection and the stress distribution in different-shaped floating membranes. The sensor sensitivity as a function of the pressure load was also calculated by experimental tests. The results of the calibration of different capacitive pressure sensors are reported in this work, together with functional tests in a wind tunnel equipped with a curved wall plate on which a DBD plasma actuator was mounted to control the flow separation. The flow behavior was experimentally investigated by particle image velocimetry (PIV) measurements. Statistical and spectral analysis, applied to the output signals of the pressure sensor placed downstream of the profile leading edge, demonstrated that the sensor is able to discriminate different ionic wind velocity and turbulence conditions. The sensor sensitivity in the 0–100 Pa range was experimentally measured and it ranged between 0.0030 and 0.0046 pF Pa −1 for the best devices. (paper)

  19. Modeling, fabrication and plasma actuator coupling of flexible pressure sensors for flow separation detection and control in aeronautical applications

    Science.gov (United States)

    Francioso, L.; De Pascali, C.; Pescini, E.; De Giorgi, M. G.; Siciliano, P.

    2016-06-01

    Preventing the flow separation could enhance the performance of propulsion systems and future civil aircraft. To this end, a fast detection of boundary layer separation is mandatory for a sustainable and successful application of active flow control devices, such as plasma actuators. The present work reports on the design, fabrication and functional tests of low-cost capacitive pressure sensors coupled with dielectric barrier discharge (DBD) plasma actuators to detect and then control flow separation. Finite element method (FEM) simulations were used to obtain information on the deflection and the stress distribution in different-shaped floating membranes. The sensor sensitivity as a function of the pressure load was also calculated by experimental tests. The results of the calibration of different capacitive pressure sensors are reported in this work, together with functional tests in a wind tunnel equipped with a curved wall plate on which a DBD plasma actuator was mounted to control the flow separation. The flow behavior was experimentally investigated by particle image velocimetry (PIV) measurements. Statistical and spectral analysis, applied to the output signals of the pressure sensor placed downstream of the profile leading edge, demonstrated that the sensor is able to discriminate different ionic wind velocity and turbulence conditions. The sensor sensitivity in the 0-100 Pa range was experimentally measured and it ranged between 0.0030 and 0.0046 pF Pa-1 for the best devices.

  20. Kerosene detection using laser induced fluorescence imaging for aeronautical engines application; Detection du kerozene par imagerie de fluorescence induite par laser, pour application sur foyer aeronautique

    Energy Technology Data Exchange (ETDEWEB)

    Baranger, Ph.

    2004-10-15

    The new concepts of aeronautical engines, developed to follow the evolution of the European standards of pollution, are generally based on an improvement of the processes of liquid fuel injection and mixture in the combustion chamber. There is currently no model mature enough to work without experimental validation. The purpose of this thesis is to assess the possibility of measuring the kerosene (Jet A1) vapour distribution by PLIF (Planar Laser Induced Fluorescence). That measurement technique must quantitatively image the instantaneous concentrations fields of the vaporized fuel in a spray. The implementation of such a technique needs an experimental spectroscopic study, which was realized on the vapour of fuel. First of all, this study allowed us to determine the properties of the kerosene fluorescence spectrum versus physical parameters such as temperature, pressure or gas mixture composition, especially in presence of oxygen molecules. Then, it was shown that the fluorescence spectrum of the fuel could be reproduce in all physical conditions by a single mixture of four aromatics. Their photophysical properties were also analyzed. Following this spectroscopic study, a phenomenological model for the fluorescence of the gaseous fuel was set up. This model led us to a protocol for an optical diagnostic on this fuel vapour. An experiment was set up to test the implementation and the limits of this technique in simple laboratory conditions. This experiment confirmed that this is indeed a promising technique for the diagnostic of the fuel vapour in aeronautical engine. (author)

  1. Program of Research in Aeronautics

    Science.gov (United States)

    1981-01-01

    A prospectus of the educational and research opportunities available at the Joint Institute for Advancement of Flight Sciences, operated at NASA Langley Research Center in conjunction with George Washington University's School of Engineering and Applied Sciences is presented. Requirements of admission to various degree programs are given as well as the course offerings in the areas of acoustics, aeronautics, environmental modelling, materials science, and structures and dynamics. Research facilities for each field of study are described. Presentations and publications (including dissertations and theses) generated by each program are listed as well as faculty members visting scientists and engineers.

  2. Characterization of Ni19.5Ti50.5Pd25Pt5 High-Temperature Shape Memory Alloy Springs and their Potential Application in Aeronautics

    Science.gov (United States)

    Stebner, Aaron; Padula, Santo A.; Noebe, Ronald D.

    2008-01-01

    Shape memory alloys (SMAs) have been used as actuators in many different industries since the discovery of the shape memory effect, but the use of SMAs as actuation devices in aeronautics has been limited due to the temperature constraints of commercially available materials. Consequently, work is being done at NASA's Glenn Research Center to develop new SMAs capable of being used in high temperature environments. One of the more promising high-temperature shape memory alloys (HTSMAs) is Ni19.5Ti50.5Pd25Pt5. Recent work has shown that this material is capable of being used in operating environments of up to 250 C. This material has been shown to have very useful actuation capabilities, demonstrating repeatable strain recoveries up to 2.5% in the presence of an externally applied load. Based on these findings, further work has been initiated to explore potential applications and alternative forms of this alloy, such as springs. Thus, characterization of Ni19.5Ti50.5Pd25Pt5 springs, including their mechanical response and how variations in this response correlate to changes in geometric parameters, are discussed. The effects of loading history, or training, on spring behavior were also investigated. A comparison of the springs with wire actuators is made and the benefits of using one actuator form as opposed to the other discussed. These findings are used to discuss design considerations for a surge-control mechanism that could be used in the centrifugal compressor of a T-700 helicopter engine.

  3. Human Factors in Aeronautics at NASA

    Science.gov (United States)

    Mogford, Richard

    2016-01-01

    This is a briefing to a regularly meeting DoD group called the Human Systems Community of Interest: Mission Effectiveness. I was asked to address human factors in aeronautics at NASA. (Exploration (space) human factors has apparently already been covered.) The briefing describes human factors organizations at NASA Ames and Langley. It then summarizes some aeronautics tasks that involve the application of human factors in the development of specific tools and capabilities. The tasks covered include aircrew checklists, dispatch operations, Playbook, Dynamic Weather Routes, Traffic Aware Strategic Aircrew Requests, and Airplane State Awareness and Prediction Technologies. I mention that most of our aeronautics work involves human factors as embedded in development tasks rather than basic research.

  4. Aerobasics–An Introduction to Aeronautics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 3. Aerobasics - An Introduction to Aeronautics - The Airplane Structure. S P Govinda Raju. Series Article Volume 15 Issue 3 March 2010 pp 206-222. Fulltext. Click here to view fulltext PDF. Permanent link:

  5. NASA's Aeronautics Vision

    Science.gov (United States)

    Tenney, Darrel R.

    2004-01-01

    Six long-term technology focus areas are: 1. Environmentally Friendly, Clean Burning Engines. Focus: Develop innovative technologies to enable intelligent turbine engines that significantly reduce harmful emissions while maintaining high performance and increasing reliability. 2. New Aircraft Energy Sources and Management. Focus: Discover new energy sources and intelligent management techniques directed towards zero emissions and enable new vehicle concepts for public mobility and new science missions. 3. Quiet Aircraft for Community Friendly Service. Focus: Develop and integrate noise reduction technology to enable unrestricted air transportation service to all communities. 4. Aerodynamic Performance for Fuel Efficiency. Focus: Improve aerodynamic efficiency,structures and materials technologies, and design tools and methodologies to reduce fuel burn and minimize environmental impact and enable new vehicle concepts and capabilities for public mobility and new science missions. 5. Aircraft Weight Reduction and Community Access. Focus: Develop ultralight smart materials and structures, aerodynamic concepts, and lightweight subsystems to increase vehicle efficiency, leading to high altitude long endurance vehicles, planetary aircraft, advanced vertical and short takeoff and landing vehicles and beyond. 6. Smart Aircraft and Autonomous Control. Focus: Enable aircraft to fly with reduced or no human intervention, to optimize flight over multiple regimes, and to provide maintenance on demand towards the goal of a feeling, seeing, sensing, sentient air vehicle.

  6. Lightning in aeronautics

    International Nuclear Information System (INIS)

    Lago, F

    2014-01-01

    It is generally accepted that a civilian aircraft is struck, on average, once or twice per year. This number tends to indicate that a lightning strike risk is far from being marginal and so requires that aircraft manufacturers have to demonstrate that their aircraft is protected against lightning. The first generation of aircrafts, which were manufactured mainly in aluminium alloy and had electromechanical and pneumatic controls, had a natural immunity to the effects of lightning. Nowadays, aircraft structures are made primarily with composite materials and flight controls are mostly electronic. This aspect of the ''more composite and more electric'' aircraft demands to aircraft manufacturers to pay a particular attention to the lightning protection and to its certification by testing and/or analysis. It is therefore essential to take this risk into account when designing the aircraft. Nevertheless, it is currently impossible to reproduce the entire lightning phenomenon in testing laboratories and the best way to analyse the lightning protection is to reproduce its effects. In this context, a number of standards and guides are produced by standards committees to help laboratories and aircraft manufacturers to perform realistic tests. Although the environment of a laboratory is quite different from those of a storm cloud, the rules of aircraft design, the know-how of aircraft manufacturers, the existence of international work leading to a better understanding of the lightning phenomenon and standards more precise, permit, today, to consider the risk as properly controlled

  7. An application of Anthony Giddens' structuration theory

    African Journals Online (AJOL)

    The aim of this article is to discuss the structuration theory of Anthony Giddens with regard to its applicability to translation studies. Key concepts of Giddens' sociological theory as agent, agency, structure, system and structuration will be explored in terms of their applicability to translation. In this article, structuration theory ...

  8. Structural Biology: Practical NMR Applications

    CERN Document Server

    Teng, Quincy

    2005-01-01

    This textbook begins with an overview of NMR development and applications in biological systems. It describes recent developments in instrument hardware and methodology. Chapters highlight the scope and limitation of NMR methods. While detailed math and quantum mechanics dealing with NMR theory have been addressed in several well-known NMR volumes, chapter two of this volume illustrates the fundamental principles and concepts of NMR spectroscopy in a more descriptive manner. Topics such as instrument setup, data acquisition, and data processing using a variety of offline software are discussed. Chapters further discuss several routine stategies for preparing samples, especially for macromolecules and complexes. The target market for such a volume includes researchers in the field of biochemistry, chemistry, structural biology and biophysics.

  9. Ultra-Lightweight Nanocomposite Foams and Sandwich Structures for Space Structures Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Space structures that are ultra-lightweight, and have gas barrier property, space durability, radiation resistance and high impact resistance are desirable to...

  10. Ultra-Lightweight Nanocomposite Foams and Sandwich Structures for Space Structures Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Space structures that are ultra-lightweight, and have gas barrier property, space durability, radiation resistance, EMI shielding, and high impact resistance are...

  11. Ultra-Lightweight Nanocomposite Foams and Sandwich Structures for Space Structures Applications, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Space structures that are ultra-lightweight, and have gas barrier property, space durability, radiation resistance, EMI shielding, and high impact resistance are...

  12. Structural Composites with Intrinsic Multifunctionality, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of a multifunctional, structural material for applications in terrestrial and space-based platforms used for instrumentation in earth observation is...

  13. Structural Composites with Intrinsic Multifunctionality, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of multifunctional, structural materials for applications in terrestrial and space-based platforms is proposed. The principle innovation is the...

  14. Materials and Structures Research for Gas Turbine Applications Within the NASA Subsonic Fixed Wing Project

    Science.gov (United States)

    Hurst, Janet

    2011-01-01

    A brief overview is presented of the current materials and structures research geared toward propulsion applications for NASA s Subsonic Fixed Wing Project one of four projects within the Fundamental Aeronautics Program of the NASA Aeronautics Research Mission Directorate. The Subsonic Fixed Wing (SFW) Project has selected challenging goals which anticipate an increasing emphasis on aviation s impact upon the global issue of environmental responsibility. These goals are greatly reduced noise, reduced emissions and reduced fuel consumption and address 25 to 30 years of technology development. Successful implementation of these demanding goals will require development of new materials and structural approaches within gas turbine propulsion technology. The Materials and Structures discipline, within the SFW project, comprise cross-cutting technologies ranging from basic investigations to component validation in laboratory environments. Material advances are teamed with innovative designs in a multidisciplinary approach with the resulting technology advances directed to promote the goals of reduced noise and emissions along with improved performance.

  15. Ultralight Core Shell Architectures for Aerospace Applications

    Data.gov (United States)

    National Aeronautics and Space Administration — Understanding the impact of integrating nanomaterials into current technology is of great importance to design composite structures to meet our application needs....

  16. Aeronautical telecommunications network advances, challenges, and modeling

    CERN Document Server

    Musa, Sarhan M

    2015-01-01

    Addresses the Challenges of Modern-Day Air Traffic Air traffic control (ATC) directs aircraft in the sky and on the ground to safety, while the Aeronautical Telecommunications Network (ATN) comprises all systems and phases that assist in aircraft departure and landing. The Aeronautical Telecommunications Network: Advances, Challenges, and Modeling focuses on the development of ATN and examines the role of the various systems that link aircraft with the ground. The book places special emphasis on ATC-introducing the modern ATC system from the perspective of the user and the developer-and provides a thorough understanding of the operating mechanism of the ATC system. It discusses the evolution of ATC, explaining its structure and how it works; includes design examples; and describes all subsystems of the ATC system. In addition, the book covers relevant tools, techniques, protocols, and architectures in ATN, including MIPv6, air traffic control (ATC), security of air traffic management (ATM), very-high-frequenc...

  17. Smart Aeronautical Chart Management System Design

    Science.gov (United States)

    Pakdil, M. E.; Celik, R. N.; Kaya, Ö.; Konak, Y. C.; Guney, C.

    2015-10-01

    Civil aviation is developing rapidly, and the number of domestic and international operations is increasing exponentially every year than the previous one. Airline companies with increased air traffic and the number of passengers increase the demand of new aircrafts. An aircraft needs not only fuel but also pilot and aeronautical information (charts, digital navigation information, flight plan, and etc.) to perform flight operation. One of the most important components in aeronautical information is the terminal chart. Authorized institution in every state is responsible to publish their terminal charts for certain periods. Although these charts are produced in accordance with ICAO's Annex 4 and Annex 15, cartographic representation and page layout differs in each state's publication. This situation makes difficult to read them by pilots. In this paper, standard instrument departure (SID) charts are analysed to produce by use of cutting-edge and competitive technologies instead of classical computer-aided drawing and vector based graphic applications that are currently used by main chart producers. The goal is to design efficient and commercial chart management system that is able to produce aeronautical charts with same cartographic representation for all states.

  18. SMART AERONAUTICAL CHART MANAGEMENT SYSTEM DESIGN

    Directory of Open Access Journals (Sweden)

    M. E. Pakdil

    2015-10-01

    Full Text Available Civil aviation is developing rapidly, and the number of domestic and international operations is increasing exponentially every year than the previous one. Airline companies with increased air traffic and the number of passengers increase the demand of new aircrafts. An aircraft needs not only fuel but also pilot and aeronautical information (charts, digital navigation information, flight plan, and etc. to perform flight operation. One of the most important components in aeronautical information is the terminal chart. Authorized institution in every state is responsible to publish their terminal charts for certain periods. Although these charts are produced in accordance with ICAO’s Annex 4 and Annex 15, cartographic representation and page layout differs in each state’s publication. This situation makes difficult to read them by pilots. In this paper, standard instrument departure (SID charts are analysed to produce by use of cutting-edge and competitive technologies instead of classical computer-aided drawing and vector based graphic applications that are currently used by main chart producers. The goal is to design efficient and commercial chart management system that is able to produce aeronautical charts with same cartographic representation for all states.

  19. Aeronautics. America in Space: The First Decade.

    Science.gov (United States)

    Anderton, David A.

    The major research and developments in aeronautics during the late 1950's and 1960's are reviewed descriptively with a minimum of technical content. Topics covered include aeronautical research, aeronautics in NASA, The National Advisory Committee for Aeronautics, the X-15 Research Airplane, variable-sweep wing design, the Supersonic Transport…

  20. 14 CFR 61.109 - Aeronautical experience.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical experience. 61.109 Section 61... Aeronautical experience. (a) For an airplane single-engine rating. Except as provided in paragraph (k) of this... have a total of 35 hours of aeronautical experience to meet the requirements of this section. [Doc. No...

  1. 14 CFR 61.129 - Aeronautical experience.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical experience. 61.129 Section 61... Aeronautical experience. (a) For an airplane single-engine rating. Except as provided in paragraph (i) of this... tracking navigational systems. This aeronautical experience may be performed in an aircraft, flight...

  2. 14 CFR 61.99 - Aeronautical experience.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical experience. 61.99 Section 61.99 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Aeronautical experience. A person who applies for a recreational pilot certificate must receive and log at...

  3. 14 CFR 61.155 - Aeronautical knowledge.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical knowledge. 61.155 Section 61....155 Aeronautical knowledge. (a) General. The knowledge test for an airline transport pilot certificate is based on the aeronautical knowledge areas listed in paragraph (c) of this section that are...

  4. Applications for the RFD linac structure

    Science.gov (United States)

    Swenson, Donald A.

    2001-07-01

    With the successful completion and operation of the "Proof-of-Principle" prototype of the Rf Focused Drift tube (RFD) linac structure, our attention has now turned to the identification of the first applications for this new compact and economical linac structure. The principal medical applications are for the production of short-lived radioisotopes for the positron emission tomography (PET and SPECT) application, epithermal neutron beams for the boron neutron capture therapy (BNCT) application, and nanoamperes of energetic (250 MeV) protons for proton therapy. The structure can be configured as a compact injector linac for proton synchrotrons. The structure can be configured as a pulsed cold neutron source to support cold neutron physics and its applications. The principal industrial applications include nondestructive testing (NDT), thermal neutron radiography (TNR), thermal neutron analysis (TNA), and pulsed fast neutron analysis (PFNA). Brief descriptions of these RFD-linac-based systems will be presented.

  5. Solar energy and the aeronautics industry. Thesis

    Science.gov (United States)

    Benedek, L.

    1985-01-01

    An introduction to the physical aspects of solar energy, incidental energy and variations in solar flux is presented, along with an explanation of the physical principles of obtaining solar energy. The history of the application of solar energy to aeronautics, including the Gossamer Penguin and the Solar Challenger is given. Finally, an analysis of the possibilities of using a reaction motor with hybrid propulsion combining solar energy with traditional fuels as well as calculations of the proposed cycle and its mode of operation are given.

  6. Preliminary experimental study on the electrical impedance analysis for in-situ monitoring of the curing of carbon/epoxy composite material for aeronautical and aerospace structures

    Science.gov (United States)

    Marguerès, Philippe; Camps, Thierry; Viargues, Mathieu; Olivier, Philippe

    2013-09-01

    This paper concerns the electrical characterization of T700/M21 unidirectional composite materials using sensors developed specifically for this study. It proposes a reliable and reproducible protocol for the characterization of the material during curing. Prior to the characterization, an analysis was carried out to assess the impact of parasitic access elements (resistance of the electrode/fibre interface or of the feed wire), which was reduced to a minimum by appropriate dimensioning of the electrodes. A study of the electrical conduction in relation to the direction of the fibres made it possible to establish a suitable approach to homogenized measurement of the material. Thermo-electric coupling by self-heating was also evaluated, with a view to obtaining measurements that were not influenced by this phenomenon. Finally, the use of electrical impedance spectral analysis allowed in-situ monitoring of the curing process. The results obtained are compared with those of a rheological analysis of the same material. These results highlight the value of the proposed protocol and demonstrate that, with the aid of these sensors, complete automation of the manufacturing process of composite structures is feasible (optimization of the cure cycle by real-time automatic control).

  7. Refractory Coated/Lined Low Density Structures, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This project addresses the development of refractory coated or lined low density structures applicable for advanced future propulsion system technologies. The...

  8. Manufacturing technologies of components for the aeronautical industry

    OpenAIRE

    Miguélez, Henar

    2008-01-01

    The team “Manufacturing Technologies” offers his experience in the research on manufacturing processes for applications in the aeronautical industry. Moreover, The team have developed works on light alloys machining, material damage related with manufacturing process and prediction of surface integrity parameters using numerical simulation. The developments are achieved in a multidisciplinary approach to a problem in the manufacturing of components for the aeronautical industry. Solutions are...

  9. Flow Quality Analysis of Shape Morphing Structures for Hypersonic Ground Testing Applications

    Data.gov (United States)

    National Aeronautics and Space Administration — Background: Shape morphing, high temperature, ceramic structural materials are now becoming available and can revolutionize ground testing by providing dynamic flow...

  10. Geopolymers for Structural Ceramic Applications

    Science.gov (United States)

    2006-08-31

    Stow, Ohio 44224 Abstract Geopolymers , also called geo- cements and low-temperature synthesized glasses, are a class of cementious materials that do...Applications of geopolymers have included ceramic matrix composites,ŕ, 3 waste encapsulation 9-11and alternative cements .7,12,14 As adhesives...and H. Schneider, The American Ceramic Society, Westerville, OH, 2003. 3J. Bell and W. M. Kriven, "Nanoporosity in geopolymeric cements " pp. 590-591

  11. 78 FR 38091 - Airworthiness Criteria: Proposed Airship Design Criteria for Lockheed Martin Aeronautics Model...

    Science.gov (United States)

    2013-06-25

    ...] Airworthiness Criteria: Proposed Airship Design Criteria for Lockheed Martin Aeronautics Model LMZ1M Airship... on the proposed design criteria for the Lockheed Martin Aeronautics model LMZ1M airship. On March 12, 2012 Lockheed Martin Aeronautics submitted an application for type certification for the model LMZ1M...

  12. Nano-Engineered Hierarchical Advanced Composite Materials for Space Applications

    Data.gov (United States)

    National Aeronautics and Space Administration — Composites are widely used throughout aerospace engineering and in numerous other applications where structures that possess high strength and toughness properties...

  13. Basic interrupt and command structures and applications

    International Nuclear Information System (INIS)

    Davies, R.C.

    1974-01-01

    Interrupt and command structures of a real-time system are described through specific examples. References to applications of a real-time system and programing development references are supplied. (auth)

  14. Ferroelectrics principles, structure and applications

    CERN Document Server

    Merchant, Serena

    2014-01-01

    Ferroelectric physics is a theory on ferroelectric phase transition for explaining various related phenomena, which is different from dielectric physics. Ferroelectric materials are important functional materials for various applications such as NVRAMs, high energy density capacitors, actuators, MEMs, sonar sensors, microphones and scanning electron microscopes (SEM). This book investigates the dielectric, ferroelectric and energy storage properties of barium zirconate-titanate/barium calcium-titanate (BZT-BCT) based ceramic for high energy density capacitors. It also compares the energy storage capabilities of ceramic powders with polymer-ceramic nanocomposites; and discusses dielectric properties of ferroelectricity in composition distributions.

  15. Structure and application of galvanomagnetic devices

    CERN Document Server

    Weiss, H

    1969-01-01

    International Series of Monographs on Semiconductors, Volume 8: Structure and Application of Galvanomagnetic Devices focuses on the composition, reactions, transformations, and applications of galvanomagnetic devices. The book first ponders on basic physical concepts, design and fabrication of galvanomagnetic devices, and properties of galvanomagnetic devices. Discussions focus on changes in electrical properties on irradiation with high-energy particles, magnetoresistor field-plate, Hall generator, preparation of semiconductor films by vacuum deposition, structure of field-plate magnetoresist

  16. On Industrial Application of Structural Reliability Theory

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    For the last two decades we have seen an increasing interest in applying structural reliability theory to many different industries. However, the number of real applications is much smaller than what one would expect. At the beginning most applications were in the design/analyses area especially ...

  17. Transparent wood for functional and structural applications

    Science.gov (United States)

    Li, Yuanyuan; Fu, Qiliang; Yang, Xuan; Berglund, Lars

    2017-12-01

    Optically transparent wood combines mechanical performance with optical functionalities is an emerging candidate for applications in smart buildings and structural optics and photonics. The present review summarizes transparent wood preparation methods, optical and mechanical performance, and functionalization routes, and discusses potential applications. The various challenges are discussed for the purpose of improved performance, scaled-up production and realization of advanced applications. This article is part of a discussion meeting issue `New horizons for cellulose nanotechnology'.

  18. Leading Edge Aeronautics Research for NASA Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The LEARN Project explores the creation of novel concepts and processes with the potential to create new capabilities in aeronautics research through awards to the...

  19. Application Software Structure Enables NIF Operations

    Energy Technology Data Exchange (ETDEWEB)

    Fong, K W; Estes, C M; Fisher, J M; Shelton, R T

    2001-10-17

    The NIF Integrated Computer Control System (ICCS) application software uses a set of service frameworks that assures uniform behavior spanning the front-end processors (FEPs) and supervisor programs. This uniformity is visible both in the way each program employs shared services and in the flexibility it affords for attaching graphical user interfaces (GUIs). Uniformity of structure across applications is desired for the benefit of programmers who will be maintaining the many programs that constitute the ICCS. In this paper, the framework components that have the greatest impact on the application structure are discussed.

  20. On industrial application of structural reliability theory

    Energy Technology Data Exchange (ETDEWEB)

    Thoft-Christensen, P

    1998-06-01

    In this paper it is shown that modern structural reliability theory is being successfully applied to a number of different industries. This review of papers is in no way complete. In the literature there is a large number of similar applications and also application not touched on in this presentation. There has been some concern among scientists from this area that structural reliability theory is not being used by industry. It is probably correct that structural reliability theory is not being used by industry as much as it should be used. However, the work by the ESReDA Working Group clearly shows the vary wide application of structural reliability theory by many different industries. One must also have in mind that industry often is reluctant to publish data related to safety and reliability. (au) 32 refs.

  1. On industrial application of structural reliability theory

    International Nuclear Information System (INIS)

    Thoft-Christensen, P.

    1998-01-01

    In this paper it is shown that modern structural reliability theory is being successfully applied to a number of different industries. This review of papers is in no way complete. In the literature there is a large number of similar applications and also application not touched on in this presentation. There has been some concern among scientists from this area that structural reliability theory is not being used by industry. It is probably correct that structural reliability theory is not being used by industry as much as it should be used. However, the work by the ESReDA Working Group clearly shows the vary wide application of structural reliability theory by many different industries. One must also have in mind that industry often is reluctant to publish data related to safety and reliability. (au)

  2. 14 CFR 61.105 - Aeronautical knowledge.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical knowledge. 61.105 Section 61... Aeronautical knowledge. (a) General. A person who is applying for a private pilot certificate must receive and... knowledge areas of paragraph (b) of this section that apply to the aircraft category and class rating sought...

  3. 76 FR 40753 - NASA Advisory Council; Aeronautics Committee; Meeting

    Science.gov (United States)

    2011-07-11

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice: (11-059)] NASA Advisory Council; Aeronautics Committee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION: Notice of..., the National Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of...

  4. Applications of Fault Detection in Vibrating Structures

    Science.gov (United States)

    Eure, Kenneth W.; Hogge, Edward; Quach, Cuong C.; Vazquez, Sixto L.; Russell, Andrew; Hill, Boyd L.

    2012-01-01

    Structural fault detection and identification remains an area of active research. Solutions to fault detection and identification may be based on subtle changes in the time series history of vibration signals originating from various sensor locations throughout the structure. The purpose of this paper is to document the application of vibration based fault detection methods applied to several structures. Overall, this paper demonstrates the utility of vibration based methods for fault detection in a controlled laboratory setting and limitations of applying the same methods to a similar structure during flight on an experimental subscale aircraft.

  5. Structural equation modeling methods and applications

    CERN Document Server

    Wang, Jichuan

    2012-01-01

    A reference guide for applications of SEM using Mplus Structural Equation Modeling: Applications Using Mplus is intended as both a teaching resource and a reference guide. Written in non-mathematical terms, this book focuses on the conceptual and practical aspects of Structural Equation Modeling (SEM). Basic concepts and examples of various SEM models are demonstrated along with recently developed advanced methods, such as mixture modeling and model-based power analysis and sample size estimate for SEM. The statistical modeling program, Mplus, is also featured and provides researchers with a

  6. Neural Network Enhanced Structure Determination of Osteoporosis, Immune System, and Radiation Repair Proteins, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a dual objective innovation that has valuable NASA applicability and tremendous commercial potential. The first innovation is the structure determination...

  7. Flexible High Energy-Conversion Sensing Materials for Structural Health Monitoring, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The applicant is developing flexible highly-efficient piezoelectric materials for use in structural health monitoring (SHM) as contemplated in the solicitation...

  8. Nuclear structure models: Applications and development

    International Nuclear Information System (INIS)

    Semmes, P.B.

    1992-07-01

    This report discusses the following topics: Studies of superdeformed States; Signature Inversion in Odd-Odd Nuclei: A fingerprint of Triaxiality; Signature Inversion in 120 Cs - Evidence for a Residual p-n Interaction; Signatures of γ Deformation in Nuclei and an Application to 125 Xe; Nuclear Spins and Moments: Fundamental Structural Information; and Electromagnetic Properties of 181 Ir: Evidence of β Stretching

  9. Numerical Methods for Structured Matrices and Applications

    CERN Document Server

    Bini, Dario A; Olshevsky, Vadim; Tyrtsyhnikov, Eugene; van Barel, Marc

    2010-01-01

    This cross-disciplinary volume brings together theoretical mathematicians, engineers and numerical analysts and publishes surveys and research articles related to the topics where Georg Heinig had made outstanding achievements. In particular, this includes contributions from the fields of structured matrices, fast algorithms, operator theory, and applications to system theory and signal processing.

  10. Mobile-ip Aeronautical Network Simulation Study

    Science.gov (United States)

    Ivancic, William D.; Tran, Diepchi T.

    2001-01-01

    NASA is interested in applying mobile Internet protocol (mobile-ip) technologies to its space and aeronautics programs. In particular, mobile-ip will play a major role in the Advanced Aeronautic Transportation Technology (AATT), the Weather Information Communication (WINCOMM), and the Small Aircraft Transportation System (SATS) aeronautics programs. This report presents the results of a simulation study of mobile-ip for an aeronautical network. The study was performed to determine the performance of the transmission control protocol (TCP) in a mobile-ip environment and to gain an understanding of how long delays, handoffs, and noisy channels affect mobile-ip performance.

  11. Designing of Metallic Photonic Structures and Applications

    International Nuclear Information System (INIS)

    Yong-Sung Kim

    2006-01-01

    In this thesis our main interest has been to investigate metallic photonic crystal and its applications. We explained how to solve a periodic photonic structure with transfer matrix method and when and how to use modal expansion method. Two different coating methods were introduced, modifying a photonic structure's intrinsic optical properties and rigorous calculation results are presented. Two applications of metallic photonic structures are introduced. For thermal emitter, we showed how to design and find optimal structure. For conversion efficiency increasing filter, we calculated its efficiency and the way to design it. We presented the relation between emitting light spectrum and absorption and showed the material and structural dependency of the absorption spectrum. By choosing a proper base material and structural parameters, we can design a selective emitter at a certain region we are interested in. We have developed a theoretical model to analyze a blackbody filament enclosed by a metallic mesh which can increase the efficiency of converting a blackbody radiation to visible light. With this model we found that a square lattice metallic mesh enclosing a filament might increase the efficiency of incandescent lighting sources. Filling fraction and thickness dependency were examined and presented. Combining these two parameters is essential to achieve the maximum output result

  12. International law and regulation of aeronautical public correspondence by satellite

    NARCIS (Netherlands)

    Brisibe, Tare

    2006-01-01

    This work covers the evolution of satellite based Aeronautical Public Correspondence and the operational environment in which services are being offered. Followed by an examination of applicable rules, including the relevant institutions from which they emanate, attention is devoted to questions on

  13. Generalized functions, convergence structures, and their applications

    CERN Document Server

    Pap, Endre; Pilipović, Stevan; Vladimirov, Vasilij; International Conference "Generalized functions, convergence structures and their applications" (GFCA-87)

    1988-01-01

    This Proceedings consists of a collection of papers presented at the International Conference "Generalized functions, convergence structures and their applications" held from June 23-27, 1987 in Dubrovnik, Yugoslavia (GFCA-87): 71 participants from 21 countr~es from allover the world took part in the Conference. Proceedings reflects the work of the Conference. Plenary lectures of J. Burzyk, J. F. Colombeau, W. Gahler, H. Keiter, H. Komatsu, B. Stankovic, H. G. Tillman, V. S. Vladimirov provide an up-to-date account of the cur­ rent state of the subject. All these lectures, except H. G. Tillman's, are published in this volume. The published communications give the contemporary problems and achievements in the theory of generalized functions, in the theory of convergence structures and in their applications, specially in the theory of partial differential equations and in the mathematical physics. New approaches to the theory of generalized functions are presented, moti­ vated by concrete problems of applicat...

  14. 14 CFR 61.97 - Aeronautical knowledge.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical knowledge. 61.97 Section 61.97... knowledge. (a) General. A person who applies for a recreational pilot certificate must receive and log... knowledge areas of paragraph (b) of this section that apply to the aircraft category and class rating sought...

  15. Structured alkali halides for medical applications

    International Nuclear Information System (INIS)

    Schmitt, B.; Fuchs, M.; Hell, E.; Knuepfer, W.; Hackenschmied, P.; Winnacker, A.

    2002-01-01

    Image plates based on storage phosphors are a major application of radiation defects in insulators. Storage phosphors absorb X-ray quanta creating trapped electron-hole pairs in the material. Optical stimulation of the electron causes recombination leading to light emission. Application of image plates requires an optimal compromise between resolution (represented by the modulation transfer function (MTF)) and sensitivity. In our paper we present a new solution of the problem of combining a high MTF with a high sensitivity by structuring the image plates in form of thin needles acting as light guides. This suppresses the lateral spread of light which is detrimental to resolution. As doped CsBr, e.g. CsBr:Ga [Physica Medica XV (1999) 301], can pose a good storage phosphor evaporated layers are of interest in computed radiography. Needle structured CsI:Tl is used as scintillator in direct radiography [IEEE Trans. Nucl. Sci. 45 (3) (1998)]. CsBr layers have been produced by evaporation in vacuum and in inert gas atmosphere varying pressure and temperature. The resulting structures are of fibrous or columnar nature being in good agreement with the zone model of Thornton [Ann. Rev. Mater. Sci. 7 (1977) 239]. A zone model for CsBr has been developed. Measurements on doped alkali halide image plates having needle structure show good MTF at high sensitivity making a significant progress in image plate technology

  16. Fluid-structure interaction and biomedical applications

    CERN Document Server

    Galdi, Giovanni; Nečasová, Šárka

    2014-01-01

    This book presents, in a methodical way, updated and comprehensive descriptions and analyses of some of the most relevant problems in the context of fluid-structure interaction (FSI). Generally speaking, FSI is among the most popular and intriguing problems in applied sciences and includes industrial as well as biological applications. Various fundamental aspects of FSI are addressed from different perspectives, with a focus on biomedical applications. More specifically, the book presents a mathematical analysis of basic questions like the well-posedness of the relevant initial and boundary value problems, as well as the modeling and the numerical simulation of a number of fundamental phenomena related to human biology. These latter research topics include blood flow in arteries and veins, blood coagulation and speech modeling. We believe that the variety of the topics discussed, along with the different approaches used to address and solve the corresponding problems, will help readers to develop a more holis...

  17. Diamond nanowires: fabrication, structure, properties, and applications.

    Science.gov (United States)

    Yu, Yuan; Wu, Liangzhuan; Zhi, Jinfang

    2014-12-22

    C(sp(3) )C-bonded diamond nanowires are wide band gap semiconductors that exhibit a combination of superior properties such as negative electron affinity, chemical inertness, high Young's modulus, the highest hardness, and room-temperature thermal conductivity. The creation of 1D diamond nanowires with their giant surface-to-volume ratio enhancements makes it possible to control and enhance the fundamental properties of diamond. Although theoretical comparisons with carbon nanotubes have shown that diamond nanowires are energetically and mechanically viable structures, reproducibly synthesizing the crystalline diamond nanowires has remained challenging. We present a comprehensive, up-to-date review of diamond nanowires, including a discussion of their synthesis along with their structures, properties, and applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Real Time Structured Light and Applications

    DEFF Research Database (Denmark)

    Wilm, Jakob

    ]. A high performance flexible open source software toolkit is presented [Contribution C], which makes real time scanning possible on commodity hardware. Further, an approach is presented to correct for motion artifacts in dynamic scenes [Contribution E]. An application for such systems is presented......, increased processing power, and methods presented in this thesis, it is possible to perform structured light scans in real time with 20 depth measurements per second. This offers new opportunities for studying dynamic scenes, quality control, human-computer interaction and more. This thesis discusses...... several aspects of real time structured light systems and presents contributions within calibration, scene coding and motion correction aspects. The problem of reliable and fast calibration of such systems is addressed with a novel calibration scheme utilising radial basis functions [Contribution B...

  19. Structural DNA Nanotechnology: From Design to Applications

    Directory of Open Access Journals (Sweden)

    Michael L. Norton

    2012-06-01

    Full Text Available The exploitation of DNA for the production of nanoscale architectures presents a young yet paradigm breaking approach, which addresses many of the barriers to the self-assembly of small molecules into highly-ordered nanostructures via construct addressability. There are two major methods to construct DNA nanostructures, and in the current review we will discuss the principles and some examples of applications of both the tile-based and DNA origami methods. The tile-based approach is an older method that provides a good tool to construct small and simple structures, usually with multiply repeated domains. In contrast, the origami method, at this time, would appear to be more appropriate for the construction of bigger, more sophisticated and exactly defined structures.

  20. Si quantum dot structures and their applications

    Science.gov (United States)

    Shcherbyna, L.; Torchynska, T.

    2013-06-01

    This paper presents briefly the history of emission study in Si quantum dots (QDs) in the last two decades. Stable light emission of Si QDs and NCs was observed in the spectral ranges: blue, green, orange, red and infrared. These PL bands were attributed to the exciton recombination in Si QDs, to the carrier recombination through defects inside of Si NCs or via oxide related defects at the Si/SiOx interface. The analysis of recombination transitions and the different ways of the emission stimulation in Si QD structures, related to the element variation for the passivation of surface dangling bonds, as well as the plasmon induced emission and rare earth impurity activation, have been presented. The different applications of Si QD structures in quantum electronics, such as: Si QD light emitting diodes, Si QD single union and tandem solar cells, Si QD memory structures, Si QD based one electron devices and double QD structures for spintronics, have been discussed as well. Note the significant worldwide interest directed toward the silicon-based light emission for integrated optoelectronics is related to the complementary metal-oxide semiconductor compatibility and the possibility to be monolithically integrated with very large scale integrated (VLSI) circuits. The different features of poly-, micro- and nanocrystalline silicon for solar cells, that is a mixture of both amorphous and crystalline phases, such as the silicon NCs or QDs embedded in a α-Si:H matrix, as well as the thin film 2-cell or 3-cell tandem solar cells based on Si QD structures have been discussed as well. Silicon NC based structures for non-volatile memory purposes, the recent studies of Si QD base single electron devices and the single electron occupation of QDs as an important component to the measurement and manipulation of spins in quantum information processing have been analyzed as well.

  1. Self Deployable Ultra-Lightweight Modular Unit for Habitat Structural Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Space deployable and rigidizable structures which are ultra-lightweight, and have high rigidity, space durability, and high impact resistance are desirable to...

  2. Self Deployable Ultra-Lightweight Modular Unit for Habitat Structural Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Space deployable and rigidizable structures which are ultra-lightweight, and have high rigidity, space durability, and high impact resistance are desirable to...

  3. Application of Advanced Radiation Shielding Materials to Inflatable Structures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This innovation is a weight-optimized, inflatable structure that incorporates radiation shielding materials into its construction, for use as a habitation module or...

  4. Design Investigation on Applicable Mesh Structures for Medical Stent Applications

    Science.gov (United States)

    Asano, Shoji; He, Jianmei

    2017-11-01

    In recent years, utilization of medical stents is one of effective treatments for stenosis and occlusion occurring in a living body’s lumen indispensable for maintenance of human life such as superficial femoral artery (SFA) occlusion. However, there are concerns about the occurrence of fatigue fractures caused by stress concentrations, neointimal hyperplasia and the like due to the shape structure and the manufacturing method in the conventional stents, and a stent having high strength and high flexibility is required. Therefore, in this research, applicable mesh structures for medical stents based on the design concepts of high strength, high flexibility are interested to solve various problem of conventional stent. According to the shape and dimensions of SFA occlusion therapy stent and indwelling delivery catheter, shape design of the meshed stent are performed using 3-dimensional CAD software Solid Works first. Then analytical examination on storage characteristics and compression characteristics of such mesh structure applied stent models were carried out through finite element analysis software ANSYS Workbench. Meshed stent models with higher strength and higher flexibility with integral molding are investigated analytically. It was found that the storage characteristics and compression characteristics of meshed stent modles are highly dependent on the basic mesh shapes with same surface void ratio. Trade-off relationship between flexibility and storage characteristics is found exited, it is required to provide appropriate curvatures during basic mesh shape design.

  5. Research and Development Progress of National Key Laboratory of Advanced Composites on Advanced Aeronautical Resin Matrix Composites

    Directory of Open Access Journals (Sweden)

    LI Bintai

    2016-06-01

    Full Text Available Applications and research progress in advanced aeronautical resin matrix composites by National Key Laboratory of Advanced Composites (LAC were summarized. A novel interlaminar toughening technology employing ultra-thin TP non-woven fabric was developed in LAC, which significantly improved the compression after impact (CAI performances of composite laminates.Newly designed multilayer sandwich stealth composite structures exhibited a good broadband radar absorbing properties at 1-18 GHz.There were remarkable developments in high toughness and high temperature resin matrix composites, covering major composite processing technologies such as prepreg-autoclave procedure, liquid composite molding and automation manufacture, etc. Finally, numerical simulation and optimization methods were deliberately utilized in the study of composites curing behavior, resin flow and curing deformation. A composite material database was also established.In conclusion, LAC has been a great support for the development of aeronautical equipment, playing such roles as innovation leading, system dominating, foundation supporting and application ensuring of aerocomposites.

  6. 77 FR 61432 - NASA Advisory Council; Aeronautics Committee; Meeting

    Science.gov (United States)

    2012-10-09

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice 12-080] NASA Advisory Council; Aeronautics Committee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION: Notice of Meeting. SUMMARY... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory...

  7. 78 FR 69885 - NASA Advisory Council; Aeronautics Committee; Meeting

    Science.gov (United States)

    2013-11-21

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice: 13-133] NASA Advisory Council; Aeronautics... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory... INFORMATION CONTACT: Ms. Susan L. Minor, Executive Secretary for the Aeronautics Committee, NASA Headquarters...

  8. Composite structural armor for combat vehicle applications

    Science.gov (United States)

    Haskell, William E., III; Alesi, A. L.; Parsons, G. R.

    1990-01-01

    Several projects that have demonstrated the advantages of using thick composite armor technology for structural applications in armored combat vehicles are discussed. The first involved composite cargo doors for the Marine Corps LVTP-7 amphibious landing vehicle. Another was a demonstration composite turret that offered a weight reduction of 15.5 percent. The advantages of this composite armor compared to metallic armors used for combat vehicle hull and turret applications are reduced weight at equal ballistic protection; reduced back armor spall; excellent corrosion resistance; reduced production costs by parts consolidation; and inherent thermal and acoustic insulative properties. Based on the encouraging results of these past programs, the Demonstration Composite Hull Program was started in September 1986. To demonstrate this composite armor technology, the Army's newest infantry fighting vehicle, the Bradley Fighting Vehicle (BFV), was selected as a model. A composite infantry fighting vehicle, designated the CIFV for this program, has been designed and fabricated and is currently undergoing a 6000 mile field endurance test. The CIFV demonstration vehicle uses the BFV engine, transmission, suspension, track and other equipment.

  9. APPLICATION OF POSTFLOTATION TAILINGS IN HYDROENGINEERING STRUCTURES

    Directory of Open Access Journals (Sweden)

    Katarzyna Stefaniak

    2017-01-01

    Full Text Available Economic development stimulated by the increased demand for production of consumer goods and the growing human population result in increasing amounts of various wastes, including tailings. The mining industry in Poland, comprising also mining of non-ferrous metal ores, is a strategic branch of the national economy and at the same time a leading waste producer. Tailings management is a significant problem both in Poland and worldwide. Frequently considerable amounts of wastes are accumulated in mine spoil tips, in areas not always suitable for their deposition, thus leading to the degradation of the surrounding environment. At the huge volume of produced wastes their rational and economically viable management is becoming crucial. On the other hand, depletion of natural aggregate deposits is an important incentive to search for substitutes, which would be suitable for the development of road infrastructure or which could be used in earth structure engineering to construct hydroengineering objects. Since no profitable recovery technologies are available at present, tailings generated by copper mining are deposited in tailings storage facilities. The largest and at the same time the only currently operating facility in Poland is the Żelazny Most Mining Tailings Storage Facility, belonging to KGHM Polska Miedź S.A. The paper presents criteria for material quality and density imposed on the material embedded in the static core of the tailings pond dam. For this purpose studies were conducted to confirm applicability of sorted tailings as a material for the construction of earth structures.

  10. Emerging Options and Opportunities in Civilian Aeronautics

    Science.gov (United States)

    Bushnell, Dennis M.

    2012-01-01

    This paper addresses the major problems/issues with civilian aeronautics going forward, the contextual ongoing technology revolutions, the several emerging civilian aeronautical "Big Ideas" and associated enabling technological approaches. The ongoing IT Revolution is increasingly providing, as 5 senses virtual presence/reality becomes available, along with Nano/Molecular Manufacturing, virtual alternatives to Physical transportation for both people and goods. Paper examines the potential options available to aeronautics to maintain and perhaps grow "market share" in the context of this evolving competition. Many of these concepts are not new, but the emerging technology landscape is enhancing their viability and marketability. The concepts vary from the "interesting" to the truly revolutionary and all require considerable research. Paper considers the speed range from personal/general aviation to supersonic transports and technologies from energetics to fabrication.

  11. Structured materials for catalytic and sensing applications

    Science.gov (United States)

    Hokenek, Selma

    The optical and chemical properties of the materials used in catalytic and sensing applications directly determine the characteristics of the resultant catalyst or sensor. It is well known that a catalyst needs to have high activity, selectivity, and stability to be viable in an industrial setting. The hydrogenation activity of palladium catalysts is known to be excellent, but the industrial applications are limited by the cost of obtaining catalyst in amounts large enough to make their use economical. As a result, alloying palladium with a cheaper, more widely available metal while maintaining the high catalytic activity seen in monometallic catalysts is, therefore, an attractive option. Similarly, the optical properties of nanoscale materials used for sensing must be attuned to their application. By adjusting the shape and composition of nanoparticles used in such applications, very fine changes can be made to the frequency of light that they absorb most efficiently. The design, synthesis, and characterization of (i) size controlled monometallic palladium nanoparticles for catalytic applications, (ii) nickel-palladium bimetallic nanoparticles and (iii) silver-palladium nanoparticles with applications in drug detection and biosensing through surface plasmon resonance, respectively, will be discussed. The composition, size, and shape of the nanoparticles formed were controlled through the use of wet chemistry techniques. After synthesis, the nanoparticles were analyzed using physical and chemical characterization techniques such as X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Scanning Transmission Electron Microscopy- Energy-Dispersive Spectrometry (STEM-EDX). The Pd and Ni-Pd nanoparticles were then supported on silica for catalytic testing using mass spectrometry. The optical properties of the Ag-Pd nanoparticles in suspension were further investigated using ultraviolet-visible spectrometry (UV-Vis). Monometallic palladium particles have

  12. Turbulent combustion modelization via a tabulation method of detailed kinetic chemistry coupled to Probability Density Function. Application to aeronautical engines; Modelisation de la combustion turbulente via une methode tabulation de la cinetique chimique detaillee couplee a des fonctions densites de probabilite. Application aux foyers aeronautiques

    Energy Technology Data Exchange (ETDEWEB)

    Rullaud, M.

    2004-06-01

    A new modelization of turbulent combustion is proposed with detailed chemistry and probability density functions (PDFs). The objective is to capture temperature and species concentrations, mainly the CO. The PCM-FTC model, Presumed Conditional Moment - Flame Tabulated Chemistry, is based on the tabulation of laminar premixed and diffusion flames to capture partial pre-mixing present in aeronautical engines. The presumed PDFs is introduced to predict averaged values. The tabulation method is based on the analysis of the chemical structure of laminar premixed and diffusion flames. Hypothesis are presented, tested and validated with Sandia experimental data jet flames. Then, the model is introduced in a turbulent flow simulation software. Three configurations are retained to quantify the level of prediction of this formulation: the D and F-Flames of Sandia and lifted jet flames of methane/air of Stanford. A good agreement is observed between experiments and simulations. The validity of this method is then demonstrated. (author)

  13. Aerobasics – An Introduction to Aeronautics

    Indian Academy of Sciences (India)

    IAS Admin

    SERIES │ ARTICLE. Aerobasics – An Introduction to Aeronautics. 12. Safety in Aviation. S P Govinda Raju. S P Govinda Raju retired as professor from the. Department of Aerospace. Engineering, Indian. Institute of Science in. 2003. He is currently active as a consultant in wind tunnel testing and teaches short term courses.

  14. Aerobasics–An Introduction to Aeronautics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 1. Aerobasics - An Introduction to Aeronautics - Safety in Aviation. S P Govinda Raju. Series Article Volume 15 Issue 1 January 2010 pp 64-75. Fulltext. Click here to view fulltext PDF. Permanent link:

  15. Aerobasics–An Introduction to Aeronautics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 10. Aerobasics – An Introduction to Aeronautics - The Atmosphere. S P Govinda Raju. Series Article ... Keywords. International Standard Atmosphere; Indian reference atmosphere; pressure altitude; atmospheric humidity; icing; gusts and winds.

  16. Aerobasics–An Introduction to Aeronautics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 4. Aerobasics-An Introduction to Aeronautics - Air Navigation Principles. S P Govinda Raju. Series Article Volume 15 Issue 4 April 2010 pp 302-320. Fulltext. Click here to view fulltext PDF. Permanent link:

  17. 400 Aerobasics–An Introduction to Aeronautics

    Indian Academy of Sciences (India)

    IAS Admin

    400. Aerobasics – An Introduction to Aeronautics. Mini and Micro Airplanes. S P Govinda Raju. GENERAL ARTICLES. 411. Bird of Passage at Four Universities. Student Days of Rudolf Peierls. G Baskaran. 428. Peierls' Elucidation of Diamagnetism. Sushanta Dattagupta. 434. The Handicap Principle. Laasya Samhita. 441.

  18. Aerobasics–An Introduction to Aeronautics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 10. Aerobasics – An Introduction to Aeronautics - The Atmosphere. S P Govinda Raju. Series Article Volume 13 Issue 10 October 2008 pp 971-977. Fulltext. Click here to view fulltext PDF. Permanent link:

  19. Aerobasics–An Introduction to Aeronautics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 2. Aerobasics–An Introduction to Aeronautics - Airfoils and Wings in Subsonic Flow. S P Govinda Raju. Series Article Volume 14 Issue 2 February 2009 pp 191-203 ...

  20. Aerobasics–An Introduction to Aeronautics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 5. Aerobasics - An Introduction to Aeronautics - Mini and Micro Airplanes. S P Govinda Raju. Series Article Volume 15 Issue 5 May 2010 pp 400-410. Fulltext. Click here to view fulltext PDF. Permanent link:

  1. Aerobasics–An Introduction to Aeronautics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 4. Aerobasics – An Introduction to Aeronautics - The Airplane Configuration. S P Govinda Raju. Series Article Volume 14 Issue 4 April 2009 pp 328-345. Fulltext. Click here to view fulltext PDF. Permanent link:

  2. Aerobasics–An Introduction to Aeronautics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 11. Aerobasics – An Introduction to Aeronautics - Airplane Basics. S P Govinda Raju. Series Article Volume 13 Issue 11 November 2008 pp 1009-1019. Fulltext. Click here to view fulltext PDF. Permanent link:

  3. Aerobasics–An Introduction to Aeronautics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 9. Aerobasics – An Introduction to Aeronautics - Historical Perspective. S P Govinda Raju. Series Article Volume 13 Issue 9 September 2008 pp 836-842. Fulltext. Click here to view fulltext PDF. Permanent link:

  4. Aerobasics–An Introduction to Aeronautics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 4. Aerobasics-An Introduction to Aeronautics - Air Navigation ... Keywords. Dead reckoning; celestial navigation; radio aids to navigation; instrument landing system (ILS); inertial navigation system (INS); global positioning system (GPS).

  5. Aerobasics–An Introduction to Aeronautics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 3. Aerobasics – An Introduction to Aeronautics - Supersonic Aerodynamics. S P Govinda Raju. Series Article Volume 14 Issue 3 March 2009 pp 272-289. Fulltext. Click here to view fulltext PDF. Permanent link:

  6. Aerobasics–An Introduction to Aeronautics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 9. Aerobasics: An Introduction to Aeronautics - Airplane Performance. S P Govinda Raju. Series Article Volume 14 Issue 9 September 2009 pp 916-928. Fulltext. Click here to view fulltext PDF. Permanent link:

  7. Ensuring US National Aeronautics Test Capabilities

    Science.gov (United States)

    Marshall, Timothy J.

    2010-01-01

    U.S. leadership in aeronautics depends on ready access to technologically advanced, efficient, and affordable aeronautics test capabilities. These systems include major wind tunnels and propulsion test facilities and flight test capabilities. The federal government owns the majority of the major aeronautics test capabilities in the United States, primarily through the National Aeronautics and Space Administration (NASA) and the Department of Defense (DoD). However, changes in the Aerospace landscape, primarily the decrease in demand for testing over the last 20 years required an overarching strategy for management of these national assets. Therefore, NASA established the Aeronautics Test Program (ATP) as a two-pronged strategic initiative to: (1) retain and invest in NASA aeronautics test capabilities considered strategically important to the agency and the nation, and (2) establish a strong, high level partnership with the DoD. Test facility utilization is a critical factor for ATP because it relies on user occupancy fees to recover a substantial part of the operations costs for its facilities. Decreasing utilization is an indicator of excess capacity and in some cases low-risk redundancy (i.e., several facilities with basically the same capability and overall low utilization). However, low utilization does not necessarily translate to lack of strategic importance. Some facilities with relatively low utilization are nonetheless vitally important because of the unique nature of the capability and the foreseeable aeronautics testing needs. Unfortunately, since its inception, the customer base for ATP has continued to shrink. Utilization of ATP wind tunnels has declined by more than 50% from the FY 2006 levels. This significant decrease in customer usage is attributable to several factors, including the overall decline in new programs and projects in the aerospace sector; the impact of computational fluid dynamics (CFD) on the design, development, and research

  8. Transmissive/Reflective Structural Color Filters: Theory and Applications

    Directory of Open Access Journals (Sweden)

    Yan Yu

    2014-01-01

    Full Text Available Structural color filters, which obtain color selection by varying structures, have attracted extensive research interest in recent years due to the advantages of compactness, stability, multifunctions, and so on. In general, the mechanisms of structural colors are based on the interaction between light and structures, including light diffraction, cavity resonance, and surface plasmon resonance. This paper reviews recent progress of various structural color techniques and the integration applications of structural color filters in CMOS image sensors, solar cells, and display.

  9. NASA's Role in Aeronautics: A Workshop. Volume I--Summary.

    Science.gov (United States)

    National Academy of Sciences - National Research Council, Washington, DC. Assembly of Engineering.

    The central task of the workshop summarized in this report was to examine the relationship of the National Aeronautics and Space Administration's (NASA's) aeronautical research capabilities to the state of U.S. aviation and to make recommendations about NASA's future roles in aeronautics. Topics include NASA's role in: (1) aeronautics research and…

  10. 75 FR 17166 - NASA Advisory Council; Aeronautics Committee; Meeting

    Science.gov (United States)

    2010-04-05

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice (10-038)] NASA Advisory Council; Aeronautics... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory... a.m. to 1 p.m.; Eastern Daylight Time. ADDRESSES: NASA Langley Research Center, Building 1219, Room...

  11. 78 FR 41114 - NASA Advisory Council; Aeronautics Committee; Meeting

    Science.gov (United States)

    2013-07-09

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice 13-075] NASA Advisory Council; Aeronautics... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory... planning. DATES: Tuesday, July 30, 2013, 9:00 a.m. to 5:00 p.m.; Local Time. ADDRESSES: NASA Headquarters...

  12. 76 FR 58843 - NASA Advisory Council; Aeronautics Committee; Meeting

    Science.gov (United States)

    2011-09-22

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice 11-082] NASA Advisory Council; Aeronautics... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory... Headquarters, Washington, DC 20546, (202) 358-0566, or [email protected]nasa.gov . SUPPLEMENTARY INFORMATION: The...

  13. 76 FR 16643 - NASA Advisory Council; Aeronautics Committee; Meeting

    Science.gov (United States)

    2011-03-24

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice (11-024)] NASA Advisory Council; Aeronautics... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory.... ADDRESSES: Thursday, April 14, 2011--NASA Dryden Flight Research Center (DFRC), Lilly Drive Building 4825...

  14. 75 FR 50782 - NASA Advisory Council; Aeronautics Committee; Meeting

    Science.gov (United States)

    2010-08-17

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice (10-087)] NASA Advisory Council; Aeronautics... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory..., 2010, 8 a.m. to 12:30 p.m.; Local Time. ADDRESSES: NASA Ames Conference Center, Building 3, 500...

  15. 78 FR 10640 - NASA Advisory Council; Aeronautics Committee; Meeting

    Science.gov (United States)

    2013-02-14

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice (13-010)] NASA Advisory Council; Aeronautics... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory..., or [email protected]nasa.gov . SUPPLEMENTARY INFORMATION: The meeting will be open to the public up to...

  16. 75 FR 41240 - NASA Advisory Council; Aeronautics Committee; Meeting

    Science.gov (United States)

    2010-07-15

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice (10-079)] NASA Advisory Council; Aeronautics... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory....m. to 4 p.m. (local time). ADDRESSES: NASA Glenn Research Center, Building 15, Small Dining...

  17. Investigation on strain sensing properties of carbon-based nanocomposites for structural aircraft applications

    Science.gov (United States)

    Lamberti, Patrizia; Spinelli, Giovanni; Tucci, Vincenzo; Guadagno, Liberata; Vertuccio, Luigi; Russo, Salvatore

    2016-05-01

    The mechanical and electrical properties of a thermosetting epoxy resin particularly indicated for the realization of structural aeronautic components and reinforced with multiwalled carbon nanotubes (MWCNTs, at 0.3 wt%) are investigated for specimens subjected to cycles and different levels of applied strain (i.e. ɛ) loaded both in axial tension and flexural mode. It is found that the piezoresistive behavior of the resulting nanocomposite evaluated in terms of variation of the electrical resistance is strongly affected by the applied mechanical stress mainly due to the high sensibility and consequent rearrangement of the electrical percolating network formed by MWCNTs in the composite at rest or even under a small strain. In fact, the variations in electrical resistance that occur during the mechanical stress are correlated to the deformation exhibited by the nanocomposites. In particular, the overall response of electrical resistance of the composite is characterized by a linear increase with the strain at least in the region of elastic deformation of the material in which the gauge factor (i.e. G.F.) of the sensor is usually evaluated. Therefore, the present study aims at investigating the possible use of the nanotechnology for application of embedded sensor systems in composite structures thus having capability of self-sensing and of responding to the surrounding environmental changes, which are some fundamental requirements especially for structural aircraft monitoring applications.

  18. Computational structural biology: methods and applications

    National Research Council Canada - National Science Library

    Schwede, Torsten; Peitsch, Manuel Claude

    2008-01-01

    ... sequencing reinforced the observation that structural information is needed to understand the detailed function and mechanism of biological molecules such as enzyme reactions and molecular recognition events. Furthermore, structures are obviously key to the design of molecules with new or improved functions. In this context, computational structural biology...

  19. The history and importance of aeronautic dentistry.

    Science.gov (United States)

    Rai, Balwant; Kaur, Jasdeep

    2011-06-01

    Current projected missions to Mars will require 18 to 24 months of exposure to microgravity conditions, which might have serious effects on human physiology, including that of the oral cavity. Very few studies have been published on the effect of microgravity on the oral cavity, although it has been reported that microgravity increases the prevalence of periodontitis, dental caries, bone loss and fracture in the jaw bone, pain and numbness in teeth and oral cavity tissue, salivary duct stones, and oral cancer. Aeronautic dentistry is a new field, so further study of the effects of microgravity are required. In this article, we review the role of aeronautic dentistry in space missions and offer our recommendations for the future growth of this field.

  20. Gulf of Mexico IFR Aeronautical Chart Index - Aeronautical Information Services Digital Products

    Data.gov (United States)

    Department of Transportation — The IFR Enroute Aeronautical Chart series is designed to meet the needs of users who require a digital version chart. This is the visual index to the charts for the...

  1. Modeling protein structures: construction and their applications.

    Science.gov (United States)

    Ring, C S; Cohen, F E

    1993-06-01

    Although no general solution to the protein folding problem exists, the three-dimensional structures of proteins are being successfully predicted when experimentally derived constraints are used in conjunction with heuristic methods. In the case of interleukin-4, mutagenesis data and CD spectroscopy were instrumental in the accurate assignment of secondary structure. In addition, the tertiary structure was highly constrained by six cysteines separated by many residues that formed three disulfide bridges. Although the correct structure was a member of a short list of plausible structures, the "best" structure was the topological enantiomer of the experimentally determined conformation. For many proteases, other experimentally derived structures can be used as templates to identify the secondary structure elements. In a procedure called modeling by homology, the structure of a known protein is used as a scaffold to predict the structure of another related protein. This method has been used to model a serine and a cysteine protease that are important in the schistosome and malarial life cycles, respectively. The model structures were then used to identify putative small molecule enzyme inhibitors computationally. Experiments confirm that some of these nonpeptidic compounds are active at concentrations of less than 10 microM.

  2. Application of molecular spectroscopy to the determination of organic structures

    International Nuclear Information System (INIS)

    Leicknam, J.P.

    1976-01-01

    Some brief accounts are presented followed by a discussion about various physico-chemical techniques: Raman spectrometry, infrared spectrometry, resonance Raman spectrometry, conformational analysis and polarized Rayleigh diffusion. Applications of the Nuclear Magnetic Resonance to nucleotide structure in aqueous solution are described as well as some applications of neutron scattering to the study of organic structures [fr

  3. Algebraic Sub-Structuring for Electromagnetic Applications

    Energy Technology Data Exchange (ETDEWEB)

    Yang, C.; Gao, W.G.; Bai, Z.J.; Li, X.Y.S.; Lee, L.Q.; Husbands, P.; Ng, E.G.; /LBL, Berkeley /UC, Davis /SLAC

    2006-06-30

    Algebraic sub-structuring refers to the process of applying matrix reordering and partitioning algorithms to divide a large sparse matrix into smaller submatrices from which a subset of spectral components are extracted and combined to form approximate solutions to the original problem. In this paper, they show that algebraic sub-structuring can be effectively used to solve generalized eigenvalue problems arising from the finite element analysis of an accelerator structure.

  4. Transonic aeroelastic numerical simulation in aeronautical engineering

    International Nuclear Information System (INIS)

    Yang, G.

    2005-01-01

    An LU-SGS (lower-upper symmetric Gauss-Seidel) subiteration scheme is constructed for time-marching of the fluid equations. The HLLEW (Harten-Lax-van Leer-Einfeldt-Wada) scheme is used for the spatial discretization. The same subiteration formulation is applied directly to the structural equations of motion in generalized coordinates. Through subiteration between the fluid and structural equations, a fully implicit aeroelastic solver is obtained for the numerical simulation of fluid/structure interaction. To improve the ability for application to complex configurations, a multiblock grid is used for the flow field calculation and Transfinite Interpolation (TFI) is employed for the adaptive moving grid deformation. The infinite plate spline (IPS) and the principal of virtual work are utilized for the data transformation between the fluid and structure. The developed code was first validated through the comparison of experimental and computational results for the AGARD 445.6 standard aeroelastic wing. Then the flutter character of a tail wing with control surface was analyzed. Finally, flutter boundaries of a complex aircraft configuration were predicted. (author)

  5. Fractografia de compósito estrutural aeronáutico submetido à caracterização de tenacidade à fratura interlaminar em modo I Fractography of aeronautical composite structures submitted to mode I interlaminar fracture toughness characterization

    Directory of Open Access Journals (Sweden)

    Geraldo Maurício Cândido

    2012-01-01

    Full Text Available Muitos componentes das modernas aeronaves estão sendo manufaturados em compósitos poliméricos. Laminados de resina epóxi modificada reforçada com fibras de carbono contínuas são empregados em estruturas primárias e secundárias para reduzir o peso e melhorar o desempenho operacional. Porém, se ocorrer uma falha circunstancial, o processo de fratura desses laminados é complexo e pode envolver mecanismos de danos interlaminares. A delaminação é a descontinuidade interlaminar que pode se propagar de forma catastrófica com a aplicação de cargas mecânicas. O ensaio de corpos de prova denominado de Double Cantilever Beam (DCB é o método mais utilizado para determinar a tenacidade à fratura em Modo I de compósitos estruturais. Neste trabalho, amostras preparadas de um laminado de tecido bidirecional, estilo plain weave, foram submetidas ao carregamento estático de delaminação em Modo I, à temperatura ambiente. A análise fractográfica das superfícies delaminadas foi realizada por microscopia eletrônica de varredura. Os resultados mostram que o processo de fratura se inicia nas bolsas de resina após um inserto de Teflon® e se propaga ao longo das regiões ricas em resina posicionadas nos interstícios de entrelaçamento das mechas da trama e da urdidura. Os principais aspectos fractográficos revelados são identificados, documentados e discutidos neste trabalho.Many components of modern aircrafts are now manufactured from polymer composites. Reinforced laminates with continuous carbon fibers and modified epoxy resin are employed in primary and secondary structures to reduce weight and improve the aircraft performance. However, if a circumstantial failure happens, the complex fracture process of the laminates may involve interlaminar damage mechanisms. The delamination is the interlaminar discontinuity which may propagate catastrophically with the application of mechanical loads. The Double Cantilever Beam (DCB is the most

  6. Mechanics of structural elements theory and applications

    CERN Document Server

    Slivker, Vladimir

    2006-01-01

    Using the variational approach, this book presents the variational principles and methods of analysis for applied elasticity and structural mechanics. Oriented towards experts in civil engineering, researchers, and software developers, this book is also useful to students of engineering, and to professors of structural analysis.

  7. A review of the Magnus effect in aeronautics

    Science.gov (United States)

    Seifert, Jost

    2012-11-01

    The Magnus effect is well-known for its influence on the flight path of a spinning ball. Besides ball games, the method of producing a lift force by spinning a body of revolution in cross-flow was not used in any kind of commercial application until the year 1924, when Anton Flettner invented and built the first rotor ship Buckau. This sailboat extracted its propulsive force from the airflow around two large rotating cylinders. It attracted attention wherever it was presented to the public and inspired scientists and engineers to use a rotating cylinder as a lifting device for aircraft. This article reviews the application of Magnus effect devices and concepts in aeronautics that have been investigated by various researchers and concludes with discussions on future challenges in their application.

  8. Development and applications of infrared structural biology

    Science.gov (United States)

    Kang, Zhouyang

    Aspartic acid (Asp), Glutamic acid (Glu) and Tyrosine (Tyr) often play critical roles at the active sites of proteins. Probing the structural dynamics of functionally important Asp/Glu and Tyr provides crucial information for protein functionality. Time-resolved infrared structural biology offers strong advantages for its high structural sensitivity and broad dynamic range (picosecond to kilosecond). In order to connect the vibrational frequencies to specific structures of COO- groups and phenolic --OH groups, such as the number, type, and geometry of hydrogen bond interactions, we develop two sets of vibrational structural markers (VSM), built on the symmetric and asymmetric stretching frequencies for COO- and C-O stretching and C-O-H bending frequencies for phenolic --OH. Extensive quantum physics (density functional theory) based computational studies, combined with site-specific isotope labeling as well as site-directed mutagenesis, and experimental FTIR data on Asp/Glu in proteins, are used to establish a unique correlation between the vibrations and multiple types of hydrogen bonding interactions. Development of those vibrational structural markers significantly enhances the power of time-resolved infrared structural biology for the study of functionally important structural dynamics of COO- from Asp/Glu and phenolic --OH from Tyr residues in proteins, including rhodopsin for biological signaling, bacteriorhodopsin and PYP for proton transfer, photosystem II for energy transformation, and HIV protease for enzymatic catalysis. Furthermore, this approach can be adopted in the future development of vibrational structural markers for other functionally important amino acid residues in proteins, such as arginine (Arg), histidine (His), and serine (Ser).

  9. Computational applications of DNA structural scales

    DEFF Research Database (Denmark)

    Baldi, P.; Chauvin, Y.; Brunak, Søren

    1998-01-01

    Studies several different physical scales associated with the structural features of DNA sequences from a computational standpoint, including dinucleotide scales, such as base stacking energy and propeller twist, and trinucleotide scales, such as bendability and nucleosome positioning. We show...

  10. The K-8 Aeronautics Internet Textbook

    Science.gov (United States)

    2002-01-01

    Efforts were focused on web site migration, from UC (University of California) Davis to the National Business Aviation Association's (NBAA) web site. K8AIT (K-8 Aeronautics Internet Textbook), which has remained an unadvertised web site, receives almost two million hits per month. Project continuation funding with the National Business Aviation Association is being pursued. A Memorandum of Understanding (MOU) between NASA Ames LTP (Learning Technologies Project) and Cislunar has been drafted and approved by NASA's legal department. Additional web content on space flight and the Wright brothers has been added in English and Spanish.

  11. Multilingual Aeronautical Dictionary (Dictionnaire Aeronautique Multilingue)

    Science.gov (United States)

    1980-01-01

    oto6op~mo FR privision WI m~tiorologique pour ES 1 psicologia ((I de aviacitin 2 rP8~4NK (ml cpeA~ero o6.ema abi6opxm 1’eironautiquo 2 psicologia (t...in) P0 psicologia MI aeronautica DE Marschgeschwindigkeit W TU hava tahmini RU sawat~motitam ncmxonormm WI ES veiccidad 1/1 mbidia 10728 TU havacilik...11243 prua (f) cardinals 12173 puntone Fm di resistenza 15126 protezione Wf del bordo d’attacco 10731 psiCologia (/).aeronautics 14411 punto Wm neutro con

  12. Evaluation of communication structures for nuclear-specific applications

    International Nuclear Information System (INIS)

    Zahedi, P.

    2007-01-01

    This paper evaluates various implementations of communication structures associated with nuclear-specific applications. Establishing numerous network structures currently used in nuclear industry, this projects analyzes the functionality and reliability of different structures. The communication structures studied in this paper include Object Linking and Embedding process control (OPC), Dynamic Data Exchange (DDE) and Modbus Communication Protocol. The experimental aspect of this project includes development and implementation of each network structure for NPP control and shutdown systems. The results of the experimentations are used to identify the potential problems of applying such structures to nuclear industry, in order to introduce nuclear-specific network structures. (author)

  13. Inorganic biomaterials structure, properties and applications

    CERN Document Server

    Zhang, Xiang C

    2014-01-01

    This book provides a practical guide to the use and applications of inorganic biomaterials. It begins by introducing the concept of inorganic biomaterials, which includes bioceramics and bioglass. This concept is further extended to hybrid biomaterials consisting of inorganic and organic materials to mimic natural biomaterials. The book goes on to provide the reader with information on biocompatibility, bioactivity and bioresorbability. The concept of the latter is important because of the increasing role resorbable biomaterials are playing in implant applications. The book also introduces a n

  14. Application of fibre reinforced plastic sandwich structures for automotive crashworthiness applications

    NARCIS (Netherlands)

    Lukaszewicz, D.; Blok, L.G.; Kratz, J.; Ward, C.; Kassapoglou, C.; Elmarakbi, A.; Araújo, A.L.

    2016-01-01

    In this work the application of fibre reinforced plastic (FRP) sandwich
    structures, with particular focus on aramid fibre tufted sandwiches is being studied for
    automotive crashworthiness applications using impact testing and numerical simulation.

  15. Probabilistic Relational Structures and Their Applications

    Science.gov (United States)

    Domotor, Zoltan

    The principal objects of the investigation reported were, first, to study qualitative probability relations on Boolean algebras, and secondly, to describe applications in the theories of probability logic, information, automata, and probabilistic measurement. The main contribution of this work is stated in 10 definitions and 20 theorems. The basic…

  16. Structural Abort Trigger for Ares Composites, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Structural health monitoring (SHM) methods have been limited for wide-area applications due to the implied infrastructure, including sensors, power/communication...

  17. Prognostics Design Solutions in Structural Health Monitoring Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — The chapter describes the application of prognostic techniques to the domain of structural health and demonstrates the efficacy of the methods using fatigue data...

  18. Antibody Modeling and Structure Analysis. Application to biomedical problems.

    OpenAIRE

    Chailyan, Anna

    2013-01-01

    Background The usefulness of antibodies and antibody derived artificial constructs in various medical and biochemical applications has made them a prime target for protein engineering, modelling, and structure analysis. The huge number of known antibody sequences, that far outpaces the number of solved structures, raises the need for reliable automatic methods of antibody structure prediction. Antibodies have a very characteristic molecular structure that is reflected in their modelli...

  19. Investigation of mesoporous structures for thermoelectric applications

    International Nuclear Information System (INIS)

    Cojocaru, A.; Carstensen, J.; Foell, H.; Boor, J.; Schmidt, V.

    2011-01-01

    Mesoporous silicon is an attractive material for thermoelectric application. For pore wall thicknesses around <100 nm, phonons can not penetrate the porous layer while electrons still can, due to there smaller mean free path length. The resulting good electrical and bad thermal conductivity is a premise for efficient thermoelectric devices. This paper presents results regarding homogeneity, high porosity, and optimal pore wall thicknesses for porous silicon based thermoelectric devices.

  20. A Robust Controller Structure for Pico-Satellite Applications

    DEFF Research Database (Denmark)

    Kragelund, Martin Nygaard; Green, Martin; Kristensen, Mads

    This paper describes the development of a robust controller structure for use in pico-satellite missions. The structure relies on unknown disturbance estimation and use of robust control theory to implement a system that is robust to both unmodeled disturbances and parameter uncertainties. As one...... possible application, a satellite mission with the purpose of monitoring shipping routes for oil spills has been considered. However, it is the aim of the control structure to be widely applicable and adaptable for a vide variety of pico-satellite missions. The robust control structure has been evaluated...

  1. Applications of the Cambridge Structural Database to molecular inorganic chemistry.

    Science.gov (United States)

    Orpen, A Guy

    2002-06-01

    Applications of the data in the Cambridge Structural Database (CSD) to knowledge acquisition and fundamental research in molecular inorganic chemistry are reviewed. Various classes of application are identified, including the derivation of typical molecular dimensions and their variability and transferability, the derivation and testing of theories of molecular structure and bonding, the identification of reaction paths and related conformational analyses based on the structure correlation hypothesis, and the identification of common and presumably energetically favourable intermolecular interactions. In many of these areas, the availability of plentiful structural data from the CSD is set against the emergence of high-quality computational data on the geometry and energy of inorganic complexes.

  2. GH62 arabinofuranosidases: Structure, function and applications

    DEFF Research Database (Denmark)

    Wilkens, Casper; Andersen, Susan; Dumon, Claire

    2017-01-01

    provides novel insights into structure/function relationships of GH62. Overall GH62 α-l-arabinofuranosidases are believed to play important roles in nature by acting in synergy with several cell wall degrading enzymes and members of GH62 represent promising candidates for biotechnological improvements......Motivated by industrial demands and ongoing scientific discoveries continuous efforts are made to identify and create improved biocatalysts dedicated to plant biomass conversion. α-1,2 and α-1,3 arabinofuranosyl specific α-l-arabinofuranosidases (EC 3.2.1.55) are debranching enzymes catalyzing...... exclusively α-l-arabinofuranosidases and these are of fungal and bacterial origin. Twenty-two GH62 enzymes out of 223 entries in the CAZy database have been characterized and very recently new knowledge was acquired with regard to crystal structures, substrate specificities, and phylogenetics, which overall...

  3. Construction of crystal structure prototype database: methods and applications.

    Science.gov (United States)

    Su, Chuanxun; Lv, Jian; Li, Quan; Wang, Hui; Zhang, Lijun; Wang, Yanchao; Ma, Yanming

    2017-04-26

    Crystal structure prototype data have become a useful source of information for materials discovery in the fields of crystallography, chemistry, physics, and materials science. This work reports the development of a robust and efficient method for assessing the similarity of structures on the basis of their interatomic distances. Using this method, we proposed a simple and unambiguous definition of crystal structure prototype based on hierarchical clustering theory, and constructed the crystal structure prototype database (CSPD) by filtering the known crystallographic structures in a database. With similar method, a program structure prototype analysis package (SPAP) was developed to remove similar structures in CALYPSO prediction results and extract predicted low energy structures for a separate theoretical structure database. A series of statistics describing the distribution of crystal structure prototypes in the CSPD was compiled to provide an important insight for structure prediction and high-throughput calculations. Illustrative examples of the application of the proposed database are given, including the generation of initial structures for structure prediction and determination of the prototype structure in databases. These examples demonstrate the CSPD to be a generally applicable and useful tool for materials discovery.

  4. Construction of crystal structure prototype database: methods and applications

    International Nuclear Information System (INIS)

    Su, Chuanxun; Lv, Jian; Wang, Hui; Wang, Yanchao; Ma, Yanming; Li, Quan; Zhang, Lijun

    2017-01-01

    Crystal structure prototype data have become a useful source of information for materials discovery in the fields of crystallography, chemistry, physics, and materials science. This work reports the development of a robust and efficient method for assessing the similarity of structures on the basis of their interatomic distances. Using this method, we proposed a simple and unambiguous definition of crystal structure prototype based on hierarchical clustering theory, and constructed the crystal structure prototype database (CSPD) by filtering the known crystallographic structures in a database. With similar method, a program structure prototype analysis package (SPAP) was developed to remove similar structures in CALYPSO prediction results and extract predicted low energy structures for a separate theoretical structure database. A series of statistics describing the distribution of crystal structure prototypes in the CSPD was compiled to provide an important insight for structure prediction and high-throughput calculations. Illustrative examples of the application of the proposed database are given, including the generation of initial structures for structure prediction and determination of the prototype structure in databases. These examples demonstrate the CSPD to be a generally applicable and useful tool for materials discovery. (paper)

  5. 77 FR 13683 - Government/Industry Aeronautical Charting Forum Meeting

    Science.gov (United States)

    2012-03-07

    ... Federal Aviation Administration Government/Industry Aeronautical Charting Forum Meeting AGENCY: Federal...-annual meeting of the Federal Aviation Administration (FAA) Aeronautical Charting Forum (ACF) to discuss... Charting Forum. BILLING CODE M ...

  6. OOA composite structures applicable in railway industry

    Directory of Open Access Journals (Sweden)

    Rusnáková Soňa

    2017-01-01

    Full Text Available Composite sandwich structures offers several advantages over conventional structural materials such as lightweight, high bending and torsional stiffness, superior thermal insulation and excellent acoustic damping. In the aerospace industry, sandwich composites are commonly manufactured using the autoclave process which is associated with high operating cost. Out-of-autoclave (OOA manufacturing has been shown to be capable of producing low cost and high performance composites. In this paper we present results of experimental testing of various sandwich materials according various standards and actual requirements in transport industry. We compared the different types of surface and paint systems, because these layers are the most important in contact with the surrounding environment and load conditions. In the experimental measurements were used various materials. For the core of the sandwich structure were selected aluminium honeycomb, aramid honeycomb and PET (Polyethylene terephthalate foam core. Support layers were chosen two kinds of predimpregnated materials. The conditions of measurements were requirements for strength and rigidity, safety - flame resistance and reflectivity resistance. The samples were tested at the 3 - point bending test according to standard EN ISO 178, by modified test to determine the force required to rapture threaded insert, by test of reflectivity according to UIC CODE 844-4 R and according to standard EN 45545-2 fire protection of railway vehicles.

  7. Review of Industrial Applications of Structural Reliability Theory

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    For the last two decades we have seen an increasing interest in applying structural reliability theory to many different industries. However, the number of real practical applications is much smaller than what one would expect....

  8. "Chameleon" Macromolecules: Synthesis, Structures and Applications of Stimulus Responsive Polymers

    NARCIS (Netherlands)

    Sui, Xiaofeng

    2012-01-01

    This thesis describes the preparation and characterization of addressable responsive polymer structures and their versatile applications. Stimuli responsive polymer chains including temperature responsive poly(N-isopropylacrylamide), PNIPAM, pH responsive poly(methacrylic acid), PMAA and redox

  9. Detonation-synthesis nanodiamonds: synthesis, structure, properties and applications

    International Nuclear Information System (INIS)

    Dolmatov, Valerii Yu

    2007-01-01

    The review outlines the theoretical foundations and industrial implementations of modern detonation synthesis of nanodiamonds and chemical purification of the nanodiamonds thus obtained. The structure, key properties and promising fields of application of detonation-synthesis nanodiamonds are considered.

  10. Geopolymers: Structures, Processing, Properties and Industrial applications

    Energy Technology Data Exchange (ETDEWEB)

    Provis, J.L.; van Deventer, J.S.J. (eds.) [University of Melbourne, Vic. (Australia)

    2009-06-15

    A geopolymer is a solid aluminosilicate material usually formed by alkali hydroxide or alkali silicate activation of a solid precursor such as coal fly ash, calcined clay and/or metallurgical slag. Part one discusses the synthesis and characterisation of geopolymers with chapters on topics such as fly ash chemistry and inorganic polymer cements, geopolymer precursor design, nanostructure/microstructure of metakaolin and fly ash geopolymers, and geopolymer synthesis kinetics. Part two reviews the manufacture and properties of geopolymers including accelerated ageing of geopolymers, chemical durability, engineering properties of geopolymer concrete, producing fire and heat-resistant geopolymers, utilisation of mining wastes and thermal properties of geopolymers. Part three covers applications of geopolymers with coverage of topics such as commercialisation of geopolymers for construction, as well as applications in waste management. Chapters of particular relevance are: Fly ash glass chemistry and inorganic polymer cements by L.M. Keyte, University of Melbourne, Australia; Nanostructure/microstructure of metakaolin geopolymers by A. Fernanez-Jimenez and A. Palomo, Eduardo Torroja Institute, Spain; Utilisation of mining wastes to produce geopolymer binders by F. Pacheco-Torgal and S. Jalali, University of Minho and J.P. Castro-Gomes, University of Beira Interior, Portugal.

  11. 78 FR 52230 - Government/Industry Aeronautical Charting Forum Meeting

    Science.gov (United States)

    2013-08-22

    ... Federal Aviation Administration Government/Industry Aeronautical Charting Forum Meeting AGENCY: Federal...-annual meeting of the Federal Aviation Administration (FAA) Aeronautical Charting Forum (ACF) to discuss...), notice is hereby given of a meeting of the FAA Aeronautical Charting Forum to be held from October 29...

  12. 75 FR 11225 - Government/Industry Aeronautical Charting Forum Meeting

    Science.gov (United States)

    2010-03-10

    ... Federal Aviation Administration Government/Industry Aeronautical Charting Forum Meeting AGENCY: Federal... Forum (ACF 10-01) to discuss informational content and design of aeronautical charts and related.... App. II), notice is hereby given of a meeting of the FAA Aeronautical Charting Forum to be held from...

  13. 77 FR 50759 - Government/Industry Aeronautical Charting Forum Meeting

    Science.gov (United States)

    2012-08-22

    ... TRANSPORTATION Federal Aviation Administration Government/Industry Aeronautical Charting Forum Meeting AGENCY... announces the bi-annual meeting of the Federal Aviation Administration (FAA) Aeronautical Charting Forum... hereby given of a meeting of the FAA Aeronautical Charting Forum to be held from October 23 through...

  14. 78 FR 12415 - Government/Industry Aeronautical Charting Forum Meeting

    Science.gov (United States)

    2013-02-22

    ... Federal Aviation Administration Government/Industry Aeronautical Charting Forum Meeting AGENCY: Federal...-annual meeting of the Federal Aviation Administration (FAA) Aeronautical Charting Forum (ACF) to discuss...), notice is hereby given of a meeting of the FAA Aeronautical Charting Forum to be held from April 23...

  15. 76 FR 12211 - Government/Industry Aeronautical Charting Forum Meeting

    Science.gov (United States)

    2011-03-04

    ... Federal Aviation Administration Government/Industry Aeronautical Charting Forum Meeting AGENCY: Federal...-annual meeting of the Federal Aviation Administration (FAA) Aeronautical Charting Forum (ACF) to discuss... of a meeting of the FAA Aeronautical ] Charting Forum to be held from April 26 through April 28, 2011...

  16. 75 FR 54221 - Government/Industry Aeronautical Charting Forum Meeting

    Science.gov (United States)

    2010-09-03

    ... Aeronautical Charting Forum Meeting AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of... Administration (FAA) Aeronautical Charting Forum (ACF) to discuss informational content and design of... the FAA Aeronautical Charting Forum to be held from October 26 through October 28, 2010, from 8:30 a.m...

  17. NASA's Role in Aeronautics: A Workshop. Volume II - Military Aviation.

    Science.gov (United States)

    National Academy of Sciences - National Research Council, Washington, DC. Assembly of Engineering.

    The central task of a 1980 workshop on the role of the National Aeronautics and Space Administration (NASA) in aeronautics was to examine the relationship of NASA's research capabilities to the state of U.S. aviation and to make recommendations about NASA's future role in aeronautics. The findings and recommendations of the Panel on Military…

  18. NASA's Role in Aeronautics: A Workshop. Volume IV - General Aviation.

    Science.gov (United States)

    National Academy of Sciences - National Research Council, Washington, DC. Assembly of Engineering.

    The central task of a 1980 workshop on the role of the National Aeronautics and Space Administration (NASA) in aeronautics was to examine the relationship of NASA's research capabilities to the state of U.S. aviation and to make recommendations about NASA's future role in aeronautics. The findings and recommendations of the Panel on General…

  19. 14 CFR 61.159 - Aeronautical experience: Airplane category rating.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical experience: Airplane category... Transport Pilots § 61.159 Aeronautical experience: Airplane category rating. (a) Except as provided in... certificate with an airplane category and class rating must have at least 1,500 hours of total time as a pilot...

  20. Applicability Problem in Optimum Reinforced Concrete Structures Design

    Directory of Open Access Journals (Sweden)

    Ashara Assedeq

    2016-01-01

    Full Text Available Optimum reinforced concrete structures design is very complex problem, not only considering exactness of calculus but also because of questionable applicability of existing methods in practice. This paper presents the main theoretical mathematical and physical features of the problem formulation as well as the review and analysis of existing methods and solutions considering their exactness and applicability.

  1. Small catalytic RNA: Structure, function and application

    Energy Technology Data Exchange (ETDEWEB)

    Monforte, Joseph Albert [Univ. of California, Berkeley, CA (United States)

    1991-04-01

    We have utilized a combination of photochemical cross-linking techniques and site-directed mutagenesis to obtain secondary and tertiary structure information for the self-cleaving, self-ligating subsequence of RNA from the negative strand of Satellite Tobacco Ringspot Virus. We have found that the helical regions fold about a hinge to promoting four different possible tertiary interactions, creating a molecular of similar shape to a paperclip. A model suggesting that the ``paperclip`` and ``hammerhead`` RNAs share a similar three dimensional structure is proposed. We have used a self-cleaving RNA molecule related to a subsequence of plant viroids, a ``hammerhead,`` to study the length-dependent folding of RNA produced during transcription by RNA polymerase. We have used this method to determine the length of RNA sequestered within elongating E. coli and T7 RNA polymerase complexes. The data show that for E. coli RNA polymerase 121±s are sequestered within the ternary complex, which is consistent with the presence of an RNA-DNA hybrid within the transcription bubble, as proposed by others. The result for T7 RNA polymerase differs from E. coli RNA polymerase, with only 10{plus_minus}1 nucleotides sequestered within the ternary complex, setting a new upper limit for the minimum RNA-DNA required for a stable elongating complex. Comparisons between E. coli and T7 RNA polymerase are made. The relevance of the results to models or transcription termination, abortive initiation, and initiation to elongation mode transitions are discussed.

  2. Generalized rough sets hybrid structure and applications

    CERN Document Server

    Mukherjee, Anjan

    2015-01-01

    The book introduces the concept of “generalized interval valued intuitionistic fuzzy soft sets”. It presents the basic properties of these sets and also, investigates an application of generalized interval valued intuitionistic fuzzy soft sets in decision making with respect to interval of degree of preference. The concept of “interval valued intuitionistic fuzzy soft rough sets” is discussed and interval valued intuitionistic fuzzy soft rough set based multi criteria group decision making scheme is presented, which refines the primary evaluation of the whole expert group and enables us to select the optimal object in a most reliable manner. The book also details concept of interval valued intuitionistic fuzzy sets of type 2. It presents the basic properties of these sets. The book also introduces the concept of “interval valued intuitionistic fuzzy soft topological space (IVIFS topological space)” together with intuitionistic fuzzy soft open sets (IVIFS open sets) and intuitionistic fuzzy soft cl...

  3. Take Off! Aeronautics and Aviation Science: Careers and Opportunities

    Science.gov (United States)

    1998-01-01

    Funded by National Aeronautic and Space Administration's High Performance Computing and Communications/ Learning Technologies Project (HPCC/LTP) Cooperative Agreement, Aeronautics and aviation Science: Careers and Opportunities was operative from July 1995 through July 1998. This project operated as a collaboration with Massachusetts Corporation for Educational Telecommunications, the Federal Aviation Administration, Bridgewater State College and four targeted "core sites" in the greater Boston area: Dorchester, Malden, East Boston and Randolph. In its first and second years, a video series with a participatory website on aeronautics and aviation science was developed and broadcast via "live, interactive" satellite feed. Accompanying teacher and student supplementary instructional materials for grades 6-12 were produced and disseminated by the Massachusetts Corporation for Educational Telecommunications (MCET). In year three, the project team redesigned the website, edited 14 videos to a five part thematic unit, and developed a teacher's guide to the video and web materials supplement for MAC and PC platforms, aligned with national standards. In the MCET grant application it states that project Take Off! in its initial phase would recruit and train teachers at "core" sites in the greater Boston area, as well as opening participation to other on-line users of MCET's satellite feeds. "Core site" classrooms would become equipped so that teachers and students might become engaged in an interactive format which aimed at not only involving the students during the "live" broadcast of the instructional video series, but which would encourage participation in electronic information gathering and sharing among participants. As a Take Off! project goal, four schools with a higher than average proportion of minority and underrepresented youth were invited to become involved with the project to give these students the opportunity to consider career exploration and development

  4. National Aeronautics and Space Administration (NASA) Earth Science Research for Energy Management. Part 1; Overview of Energy Issues and an Assessment of the Potential for Application of NASA Earth Science Research

    Science.gov (United States)

    Zell, E.; Engel-Cox, J.

    2005-01-01

    Effective management of energy resources is critical for the U.S. economy, the environment, and, more broadly, for sustainable development and alleviating poverty worldwide. The scope of energy management is broad, ranging from energy production and end use to emissions monitoring and mitigation and long-term planning. Given the extensive NASA Earth science research on energy and related weather and climate-related parameters, and rapidly advancing energy technologies and applications, there is great potential for increased application of NASA Earth science research to selected energy management issues and decision support tools. The NASA Energy Management Program Element is already involved in a number of projects applying NASA Earth science research to energy management issues, with a focus on solar and wind renewable energy and developing interests in energy modeling, short-term load forecasting, energy efficient building design, and biomass production.

  5. Ultrathin magnetic structures IV applications of nanomagnetism

    CERN Document Server

    Heinrich, Bretislav

    2004-01-01

    The ability to understand and control the unique properties of interfaces has created an entirely new field of magnetism which already has a profound impact in technology and is providing the basis for a revolution in electronics. The last decade has seen dramatic progress in the development of magnetic devices for information technology but also in the basic understanding of the physics of magnetic nanostructures. Volume III describes thin film magnetic properties and methods for characterising thin film structure topics that underpin the present 'spintronics' revolution in which devices are based on combined magnetic materials and semiconductors. The present volume (IV) deals with the fundamentals of spintronics: magnetoelectronic materials, spin injection and detection, micromagnetics and the development of magnetic random access memory based on GMR and tunnel junction devices. Together these books provide readers with a comprehensive account of an exciting and rapidly developing field. The treatment is de...

  6. Structural shell analysis understanding and application

    CERN Document Server

    Blaauwendraad, Johan

    2014-01-01

    The mathematical description of the properties of a shell is much more elaborate than those of beam and plate structures. Therefore many engineers and architects are unacquainted with aspects of shell behaviour and design, and are not familiar with sufficiently reliable shell theories for the different shell types as derived in the middle of the 20th century. Rather than contributing to theory development, this university textbook focuses on architectural and civil engineering schools. Of course, practising professionals will profit from it as well. The book deals with thin elastic shells, in particular with cylindrical, conical and spherical types, and with elliptic and hyperbolic paraboloids. The focus is on roofs, chimneys, pressure vessels and storage tanks. Special attention is paid to edge bending disturbance zones, which is indispensable knowledge in FE meshing. A substantial part of the book results from research efforts in the mid 20th century at Delft University of Technology. As such, it is a valua...

  7. Small catalytic RNA: Structure, function and application

    Energy Technology Data Exchange (ETDEWEB)

    Monforte, J.A.

    1991-04-01

    We have utilized a combination of photochemical cross-linking techniques and site-directed mutagenesis to obtain secondary and tertiary structure information for the self-cleaving, self-ligating subsequence of RNA from the negative strand of Satellite Tobacco Ringspot Virus. We have found that the helical regions fold about a hinge to promoting four different possible tertiary interactions, creating a molecular of similar shape to a paperclip. A model suggesting that the paperclip'' and hammerhead'' RNAs share a similar three dimensional structure is proposed. We have used a self-cleaving RNA molecule related to a subsequence of plant viroids, a hammerhead,'' to study the length-dependent folding of RNA produced during transcription by RNA polymerase. We have used this method to determine the length of RNA sequestered within elongating E. coli and T7 RNA polymerase complexes. The data show that for E. coli RNA polymerase 12{plus minus}1 nucleotides are sequestered within the ternary complex, which is consistent with the presence of an RNA-DNA hybrid within the transcription bubble, as proposed by others. The result for T7 RNA polymerase differs from E. coli RNA polymerase, with only 10{plus minus}1 nucleotides sequestered within the ternary complex, setting a new upper limit for the minimum RNA-DNA required for a stable elongating complex. Comparisons between E. coli and T7 RNA polymerase are made. The relevance of the results to models or transcription termination, abortive initiation, and initiation to elongation mode transitions are discussed.

  8. Applications of an educational structure for learning law

    NARCIS (Netherlands)

    Barojos Weber, J.; Muntjewerff, A.J.

    2010-01-01

    This work concerns how to support instruction to enhance efficient and effective learning of the law. First, an Educational Structure for Learning is described. Then, the use of this Structure as a framework for assessing and interpreting three practical applications is presented: (1) the design and

  9. Aeronautics. An Educator's Guide with Activities in Science, Mathematics, and Technology Education: What Pilot, Astronaut, or Aeronautical Engineer didn't Start out with a Toy Glider?

    Science.gov (United States)

    Biggs, Pat (Editor); Huetter, Ted (Editor)

    1998-01-01

    Welcome to the exciting world of aeronautics. The term aeronautics originated in France, and was derived from the Greek words for "air" and "to sail." It is the study of flight and the operation of aircraft. This educator guide explains basic aeronautical concepts, provides a background in the history of aviation, and sets them within the context of the flight environment (atmosphere, airports, and navigation). The activities in this guide are designed to be uncomplicated and fun. They have been developed by NASA Aerospace Education Services Program specialists, who have successfully used them in countless workshops and student programs around the United States. The activities encourage students to explore the nature of flight, and experience some real-life applications of mathematics, science, and technology. The subject of flight has a wonderful power to inspire learning.

  10. Research applications of the Cambridge Structural Database (CSD).

    Science.gov (United States)

    Allen, Frank H; Taylor, Robin

    2004-10-20

    Crystal structure data are of fundamental importance in a wide spectrum of scientific activities. This tutorial review summarises the principal application areas, so far, for the data from more than 300,000 crystal structures of small organic and metal-organic compounds that are stored in the Cambridge Structural Database (CSD). Direct use of the accumulated data is valuable in establishing standard molecular dimensions, determining conformational preferences and in the study of intermolecular interactions, all of which are crucial in structural chemistry and rational drug design. More recently, information derived from the CSD has been used to construct two dynamic libraries of structural knowledge: Mogul, which stores intramolecular information, and IsoStar, which stores information about intermolecular interactions. These electronic libraries provide information "at the touch of a button". In their turn, the libraries also serve as sources of structural knowledge for applications software that address specific problems in small-molecule and biological chemistry.

  11. High performance hybrid magnetic structure for biotechnology applications

    Science.gov (United States)

    Humphries, David E [El Cerrito, CA; Pollard, Martin J [El Cerrito, CA; Elkin, Christopher J [San Ramon, CA

    2009-02-03

    The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides means for separation and other biotechnology applications involving holding, manipulation, or separation of magnetic or magnetizable molecular structures and targets. Also disclosed are further improvements to aspects of the hybrid magnetic structure, including additional elements and for adapting the use of the hybrid magnetic structure for use in biotechnology and high throughput processes.

  12. Application of betatrons to quality control of structures

    International Nuclear Information System (INIS)

    Klevtsov, V.A.; Matveev, Yu.K.; Trefilov, V.V.

    1986-01-01

    The results of laboratory investigations on the applicability of modificated PMB-6 betatron to quality control of reinforced concrete structures are presented. The investigations have been performed for the purposes of refinement of the technique for detecting voids and establishing real reinforcement. On the basis of experimental investigations the technique and schemes of structure translucence have been developed. Examples of using betatrons for flaw detection of reinforred concrete structures are given

  13. materials.forum 2005 - Comparing light-weight concepts in vehicle and aeronautical engineering. Conference proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The proceedings volume of the two days Conference titled:''materials.forum 2005 - Comparing light-weight concepts in vehicle and aeronautical engineering'' which has been held on th 22nd and 23rd November 2005 in Munich, Germany, includes the 19 contributions presented. Light-weight construction plays an essential role in modern vehicle and aeronautical engineering and furthermore becomes more and more important. The requirements for light-weight structures are multiple considering adequate construction, resources, economical production and mobility. The fundamental success factor for effective solutions on material engineering consists of forward thinking and project orientated cooperation in partnership with producers, fabricators, component suppliers and manufacturers. The main emphasis of the ''materials.forum 2005'' was to draw the comparison of property-patterns of different material groups; manufacturing technologies; and fields of application for different materials in modern light-weight construction. The subjects dealt with in detail were as follows: synergies between automotive engineering and aerospace; high- performance materials in the example of the Transrapid; GLARE - Industrialization of an advanced light-weight material; Aluminium/composite in rail transport; optimisation of hybrid-material light-weight structures including manufacturing aspects; applications of light alloys in transport engineering (dars, railways, aeroplanes); light-weight construction in the motor vehicle using new materials; development of a body floor structure in steel lightweight design with improved side impact behaviour; how weighty is our mobility?; the whole is greater than its parts: materials in transport engineering; plastic body panels; high-temperature composite materials for aircraft engines; the potential of natural-fiber-reinforced biopolymers for standard production applications in the railway vehicle sector; mixed

  14. Development of a Computer Application to Simulate Porous Structures

    Directory of Open Access Journals (Sweden)

    S.C. Reis

    2002-09-01

    Full Text Available Geometric modeling is an important tool to evaluate structural parameters as well as to follow the application of stereological relationships. The obtention, visualization and analysis of volumetric images of the structure of materials, using computational geometric modeling, facilitates the determination of structural parameters of difficult experimental access, such as topological and morphological parameters. In this work, we developed a geometrical model implemented by computer software that simulates random pore structures. The number of nodes, number of branches (connections between nodes and the number of isolated parts, are obtained. Also, the connectivity (C is obtained from this application. Using a list of elements, nodes and branches, generated by the software, in AutoCAD® command line format, the obtained structure can be viewed and analyzed.

  15. Aeronautical Mobile Airport Communications System (AeroMACS)

    Science.gov (United States)

    Budinger, James M.; Hall, Edward

    2011-01-01

    To help increase the capacity and efficiency of the nation s airports, a secure wideband wireless communications system is proposed for use on the airport surface. This paper provides an overview of the research and development process for the Aeronautical Mobile Airport Communications System (AeroMACS). AeroMACS is based on a specific commercial profile of the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard known as Wireless Worldwide Interoperability for Microwave Access or WiMAX (WiMax Forum). The paper includes background on the need for global interoperability in air/ground data communications, describes potential AeroMACS applications, addresses allocated frequency spectrum constraints, summarizes the international standardization process, and provides findings and recommendations from the world s first AeroMACS prototype implemented in Cleveland, Ohio, USA.

  16. TRENDS: The aeronautical post-test database management system

    Science.gov (United States)

    Bjorkman, W. S.; Bondi, M. J.

    1990-01-01

    TRENDS, an engineering-test database operating system developed by NASA to support rotorcraft flight tests, is described. Capabilities and characteristics of the system are presented, with examples of its use in recalling and analyzing rotorcraft flight-test data from a TRENDS database. The importance of system user-friendliness in gaining users' acceptance is stressed, as is the importance of integrating supporting narrative data with numerical data in engineering-test databases. Considerations relevant to the creation and maintenance of flight-test database are discussed and TRENDS' solutions to database management problems are described. Requirements, constraints, and other considerations which led to the system's configuration are discussed and some of the lessons learned during TRENDS' development are presented. Potential applications of TRENDS to a wide range of aeronautical and other engineering tests are identified.

  17. Achieving QoS for Aeronautical Telecommunication Networks Over Differentiated Services

    Science.gov (United States)

    Bai, Haowei; Atiquzzaman, Mohammed; Ivanic, William

    2001-01-01

    Aeronautical Telecommunication Network (ATN) has been developed by the International Civil Aviation Organization to integrate Air-Ground and Ground-Ground data communication for aeronautical applications into a single network serving Air Traffic Control and Aeronautical Operational Communications. To carry time critical information required for aeronautical applications, ATN provides different Quality of Services (QoS) to applications. ATN has therefore, been designed as a stand alone network which implies building an expensive separate network for ATN However, the cost of operating ATN can be reduced if it can be run over a public network such as the Internet. Although the current Internet does not provide QoS the next generation Internet is expected to provide QoS to applications. The objective of this paper is to investigate the possibility of providing QoS to ATN applications when it is run over the next generation Internet. Differentiated Services (DiffServ), one of the protocols proposed for the next generation Internet, will allow network service providers to offer different QoS to customers. Our results show that it is possible to provide QoS to ATN applications when they run over a DiffServ backbone.

  18. Integrated Composite Structure for EDL Application, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has defined a need for higher performance ablative Thermal Protection System (TPS) materials for future exploration of our solar system's inner and outer...

  19. Graphitic Carbon Foam Structural Cores and Multifunctional Applications

    Data.gov (United States)

    National Aeronautics and Space Administration — Graphitic carbon foams include a family of material forms and products with mechanical, thermal, and electrical properties that are tailor-able over a wide range....

  20. Optimisation of thermo mechanical treatments using ECAP and aging for an aluminium alloy for automotive and aeronautical applications; Thermomechanische Optimierung mittels ECAP und Waermebehandlung an einer Aluminiumlegierung der Automobil- und Luftfahrtindustrie

    Energy Technology Data Exchange (ETDEWEB)

    Hockauf, K.; Meyer, L.W. [Nordmetall Research and Consulting GmbH, Adorf (Neukirchen) (Germany); Halle, T.; Hockauf, M.; Wagner, M.F.X.; Lampke, T. [Technische Universitaet Chemnitz, Institut fuer Werkstoffwissenschaft und Werkstofftechnik, Chemnitz (Germany)

    2010-09-15

    In this work, the promising approach of a combined equal-channel angular pressing (ECAP) and aging treatment was applied to an Al-Mg-Si-(Cu) alloy. With the aim of improving the strength and preserving a moderate ductility, this method consists of a severe plastic deformation in the solid-solution heat-treated condition and a subsequent aging to peak strength. For the following aging treatment, time and temperature are balanced in order to enable precipitation hardening up to the peak strength on the one hand and microstructural recovery of the severely work hardened material on the other hand. The main focus of this work lies on the influence of the aging time and temperature on the evolution of strength and ductility of the ECAP-processed material. The underlying microstructural features, such as dislocation structures and precipitation characteristics, are evaluated by means of low-voltage scanning transmission electron microscopy. In comparison to the initial peak aged condition, an increase in strength of about 27%, combined with a uniform elongation of 6.5% and a total elongation of 20%, was achieved by two ECAP-passes and a subsequent aging to peak strength at 150 C. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  1. Field application of cathodic prevention on reinforced concrete structures

    Energy Technology Data Exchange (ETDEWEB)

    Bazzoni, A.; Bazzoni, B.; Lazzari, L. [Cescor srl, Milano (Italy); Bertolini, L.; Pedeferri, P. [Politecnico di Milano (Italy). Dept. di Chimica Fisica Applicata

    1996-11-01

    This paper illustrates the results gained during the first three years of cathodic protection application to Frejus highway viaducts in northern Italy. CP applications deal with corrosion control of chloride contaminated structures (cathodic protection application properly said) and the corrosion prevention of new non-contaminated structures, constructed with incorporated cathodic protection systems (so-called cathodic prevention). Both normal and post-tensioned structures are present: in the latter case the problems connected with the risk of hydrogen embrittlement of the tendons are discussed. The paper illustrates also the computerized system for gathering and monitoring data and the criteria adopted to evaluate and control the cathodic protection and cathodic prevention conditions as well as to avoid overprotection.

  2. Applications of Fluorogens with Rotor Structures in Solar Cells

    Directory of Open Access Journals (Sweden)

    Kok-Haw Ong

    2017-05-01

    Full Text Available Solar cells are devices that convert light energy into electricity. To drive greater adoption of solar cell technologies, higher cell efficiencies and reductions in manufacturing cost are necessary. Fluorogens containing rotor structures may be helpful in addressing some of these challenges due to their unique twisted structures and photophysics. In this review, we discuss the applications of rotor-containing molecules as dyes for luminescent down-shifting layers and luminescent solar concentrators, where their aggregation-induced emission properties and large Stokes shifts are highly desirable. We also discuss the applications of molecules containing rotors in third-generation solar cell technologies, namely dye-sensitized solar cells and organic photovoltaics, where the twisted 3-dimensional rotor structures are used primarily for aggregation control. Finally, we discuss perspectives on the future role of molecules containing rotor structures in solar cell technologies.

  3. Applications of Fluorogens with Rotor Structures in Solar Cells.

    Science.gov (United States)

    Ong, Kok-Haw; Liu, Bin

    2017-05-29

    Solar cells are devices that convert light energy into electricity. To drive greater adoption of solar cell technologies, higher cell efficiencies and reductions in manufacturing cost are necessary. Fluorogens containing rotor structures may be helpful in addressing some of these challenges due to their unique twisted structures and photophysics. In this review, we discuss the applications of rotor-containing molecules as dyes for luminescent down-shifting layers and luminescent solar concentrators, where their aggregation-induced emission properties and large Stokes shifts are highly desirable. We also discuss the applications of molecules containing rotors in third-generation solar cell technologies, namely dye-sensitized solar cells and organic photovoltaics, where the twisted 3-dimensional rotor structures are used primarily for aggregation control. Finally, we discuss perspectives on the future role of molecules containing rotor structures in solar cell technologies.

  4. Structured Control of LPV Systems with Application to Wind Turbines

    OpenAIRE

    Adegas, Fabiano Daher; Stoustrup, Jakob

    2012-01-01

    This paper deals with structured control of linear parameter varying systems (LPV) with application to wind turbines. Instead of attempting to reduce the problem to linear matrix inequalities (LMI), we propose to design the controllersvia an LMI-based iterative algorithm. The proposed algorithm can synthesize structured controllers like decentralized, static output and reduced order output feedback for discrete-time LPV systems. Based on a coordinate decent, it relies on a sufficient matrix i...

  5. Hierarchical structure for risk criteria applicable to nuclear power plants

    International Nuclear Information System (INIS)

    Hall, R.E.; Mitra, S.P.

    1985-01-01

    This paper discusses the development of a hierarchical structure for risk criteria applicable to nuclear power plants. The structure provides a unified framework to systematically analyze the implications of different types of criteria, each focusing on a particular aspect of nuclear power plant risks. The framework allows investigation of the specific coverage of a particular criterion and comparison of different criteria with regard to areas to which they apply. 5 refs., 2 figs

  6. The application of new mathematical structures to safety analysis

    International Nuclear Information System (INIS)

    Cooper, J.A.; Ross, T.J.

    1997-10-01

    Probabilistic safety analyses (PSAs) often depend on significant subjectivity. The recent successes of fuzzy logic and fuzzy and hybrid mathematics in portraying subjectivity is a reminder that a selection made from the most applicable mathematical tools is more important than forced adaptation of conventional tools. In this paper, the authors consider new approaches that enhance conventional and fuzzy PSA by improved handling of subjectivity. The most significant of the mathematical structures were have investigated (from a standpoint of safety analysis applications) will be described, and the general types of applications will be outlined

  7. Structural Equation Modeling with Mplus Basic Concepts, Applications, and Programming

    CERN Document Server

    Byrne, Barbara M

    2011-01-01

    Modeled after Barbara Byrne's other best-selling structural equation modeling (SEM) books, this practical guide reviews the basic concepts and applications of SEM using Mplus Versions 5 & 6. The author reviews SEM applications based on actual data taken from her own research. Using non-mathematical language, it is written for the novice SEM user. With each application chapter, the author "walks" the reader through all steps involved in testing the SEM model including: an explanation of the issues addressed illustrated and annotated testing of the hypothesized and post hoc models expl

  8. Printed Ultra-High Temperature NDE Sensors for Complex Structures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I SBIR proposal will address the use of innovative additive manufacturing technologies applicable to Non-Destructive Evaluation (NDE) and Structural...

  9. Novel, Functionally Graded PIP Coating System for Hot Structures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal addresses some of the most challenging materials issues with respect to Hot Structures, very high temperature, up to 4000 degrees F, applications. The...

  10. Structural Health Monitoring Using Fiber Bragg Grating Sensor Matrix, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Fiber Bragg Grating had been identified as very important elements, especially for strain measurements in smart structures. In many applications, arrays of FBG...

  11. Portfolio of Potential Strategies in Aeronautic Maintenance

    Science.gov (United States)

    Rolet, S.

    2010-02-01

    EADS divisions aim more and more at developing services associated to their platforms. EADS divisions, like Airbus and Eurocopter, are investigating on services associated to their platforms in order to add them value. One possible service consists in structural maintenance operation assistance, especially for NDT operations performed by the customer. EADS Innovation Works envisages three different and complementary enhanced structural maintenance categories. Enhanced NDT improves standard NDT operation environment. This is made possible by the existence of "smart" NDT tools that are computer based and therefore able to support other functions. These functions range from local smart data processing and display to remote expert assisted operation. Passive Sensor Network relies on sensors permanently installed on aircraft structure. Interrogation of sensors is performed on ground and off line (while structure is not loaded except by its own weight). It can be done at arbitrary times in order to determine structure health. The aim is to give easy access to some hidden "hot spots," to reduce human factor in structure health assessment and optimize maintenance. Structural Health Monitoring goes a step beyond Passive Sensor Network, because interrogation units are on board the aircraft and may be connected to aircraft network. It allows to use on-line techniques such as adapted acoustic emission and to automatically raise an alarm when a defect appears in the structure. This paper presents these different ways of improving structural maintenance operations in service, with their respective advantages and limitations.

  12. Classification of Aeronautics System Health and Safety Documents

    Data.gov (United States)

    National Aeronautics and Space Administration — Most complex aerospace systems have many text reports on safety, maintenance, and associated issues. The Aviation Safety Reporting System (ASRS) spans several...

  13. Conformal Lightweight Antenna Structures for Aeronautical Communication Technologies

    Science.gov (United States)

    Meador, Mary Ann

    2017-01-01

    This project is to develop antennas which enable beyond line of sight (BLOS) command and control for UAVs. We will take advantage of newly assigned provisional Ku-band spectrum for UAVs and use unique antenna designs to avoid interference with ground systems. This will involve designing antennas with high isotropic effective radiated power (EIRP) and ultra-low sidelobes. The antennas will be made with polymer aerogel as a substrate to both reduce weight and improve performance, as demonstrated in an Aero Seedling. In addition, designing the antennas to be conformal to the aircraft fuselage will reduce drag.

  14. Piezoelectric MEMS Microphones for Ground Testing of Aeronautical Systems, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Improving the acoustical environment is critical in aeronautics. Airports and aeronautical systems manufacturers are facing ever-increasing demands to reduce noise...

  15. Piezoelectric MEMS Microphones for Ground Testing of Aeronautical Systems, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Improving the acoustical environment is critical in aeronautics. Airports and aeronautical systems manufacturers are facing ever-increasing demands to reduce noise...

  16. Optical-based smart structures for tamper-indicating applications

    International Nuclear Information System (INIS)

    Sliva, P.; Anheier, N.C.; Simmons, K.L.; Undem, H.A.

    1996-11-01

    This report is a compilation of several related projects performed from 1991 through 1996 concerning the design, construction, and application of optical-based smart structure to tamper-indicating and sensing secure containers. Due to several influences, the projects were carried through to varying degrees of completion. Cancellation of the overall project at the client level motivated the authors to gather all of the technology and ideas about smart structures developed during these several projects, whether completed or just conceptualized, into one document. Although each section individually discusses a specific project, the overall document is written chronologically with each successive section showing how increased smart structure complexity was integrated into the container

  17. Global models for studying the non linear behavior of structures. Application to reinforced concrete structures

    International Nuclear Information System (INIS)

    Millard, A.; Hoffmann, A.; Gauvain, J.; Nahas, G.

    1982-06-01

    The application of global methods to design reinforced concrete structures was investigated. The dynamic calculation of beam structures can be carried out very economically and with suitable accuracy by these methods. Moreover, one ideal application of global methods is design to failure, in order to estimate the safety margins of a given structure subject to accidental stresses, such as explosions, earthquakes, aircraft crash etc. In all cases, the global method combined with finite element programs serves to determine the failure automatically, and offers a good estimate of the failure load [fr

  18. [Toxological problems inherent in varnish and paint products used in aeronautics].

    Science.gov (United States)

    Cianetti, E; Bancheri, C

    1977-12-15

    Paint products and the need for their employment on aircraft and spacecraft are described and reference is made to the types of poisoning that may arise from their application. The main solvents and diluents are listed, together with their toxicological features. Lastly, mention is made of technical products required by the aeronautical regulations, the dangers associated with them, and the preventive measures required.

  19. Novel Hybrid Polymeric and Inorganic Structures for Applications in Nanobiotechnology

    OpenAIRE

    Valdeperez Toledo, Daniel; Parak, Wolfgang J. (Prof. Dr.)

    2017-01-01

    This cumulative doctoral dissertation deals with the use of diverse polymers in different applications within nanoscience. The synthesis and characterization of several nano and microstructures is also explained, focusing on the later surface modification via the use of different polymers. Polymers are chemical compounds formed by the combination of several repeating structural units (monomers) in a process called polymerization. ...

  20. Plant retroviruses: structure, evolution and future applications | Zaki ...

    African Journals Online (AJOL)

    Until recently, retroviruses were thought to be restricted to vertebrates. Plant sequencing projects revealed that plant genomes contain retroviral-like sequences. This review aims to address the structure and evolution of plant retroviruses. In addition, it proposes future applications for these important key components of plant ...

  1. ALL NATURAL COMPOSITE SANDWICH BEAMS FOR STRUCTURAL APPLICATIONS. (R829576)

    Science.gov (United States)

    As part of developing an all natural composite roof for housing application,structural panels and unit beams were manufactured out of soybean oil based resinand natural fibers (flax, cellulose, pulp, recycled paper, chicken feathers)using vacuum assisted resin tran...

  2. Aluminium structures in building and civil engineering applications

    NARCIS (Netherlands)

    Soetens, F.

    2010-01-01

    Structural applications of aluminium are considered in this paper. Although the discussion is mainly devoted to Europe, the paper also refers, where possible, to developments in other parts of the world. The problems faced by a designer in creating an optimum design are described, followed by a

  3. Applications of Asymptotic Sampling on High Dimensional Structural Dynamic Problems

    DEFF Research Database (Denmark)

    Sichani, Mahdi Teimouri; Nielsen, Søren R.K.; Bucher, Christian

    2011-01-01

    The paper represents application of the asymptotic sampling on various structural models subjected to random excitations. A detailed study on the effect of different distributions of the so-called support points is performed. This study shows that the distribution of the support points has consid...

  4. Synthesis, structure and applications of [cis-dioxomolybdenum (VI ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 123; Issue 2. Synthesis, structure and applications of [cis-dioxomolybdenum(VI)-(ONO)] type complexes. Rajan Deepan Chakravarthy Dillip Kumar Chand. Volume 123 Issue 2 March 2011 pp 187-199 ... http://www.ias.ac.in/article/fulltext/jcsc/123/02/0187-0199 ...

  5. Recent Research and Application Activities on Structural Health ...

    African Journals Online (AJOL)

    Journal of Civil Engineering Research and Practice ... In this paper, current status of research and application activities on SHM systems for civil infra-structures in Korea are briefly introduced in four parts: (1) current status of bridge monitoring systems on existing and newly constructed bridges, (2) research and ...

  6. Synthesis, structure and applications of [cis-dioxomolybdenum (VI ...

    Indian Academy of Sciences (India)

    Oxo-molybdenum chemistry is of great interest since such units are found in the active sites of a majority of molybdo-enzymes. In order to mimic the biological systems, a number of oxo-molybdenum complexes have been synthesised and studied. This review describes synthesis, structure and applications of ...

  7. Ceramic materials on perovskite-type structure for electronic applications

    International Nuclear Information System (INIS)

    Surowiak, Z.

    2003-01-01

    Ceramic materials exhibiting the perovskite-type structure constitute among others, resource base for many fields of widely understood electronics (i.e., piezoelectronics, accustoelectronics, optoelectronics, computer science, tele- and radioelectronics etc.). Most often they are used for fabrication of different type sensors (detectors), transducers, ferroelectric memories, limiters of the electronic current intensity, etc., and hence they are numbered among so-called intelligent materials. Prototype structure of this group of materials is the structure of the mineral called perovskite (CaTiO 3 ). By means of right choice of the chemical composition of ABO 3 and deforming the regular perovskite structure (m3m) more than 5000 different chemical compounds and solid solutions exhibiting the perovskite-type structure have been fabricated. The concept of perovskite functional ceramics among often things ferroelectric ceramics, pyroelectric ceramics, piezoelectric ceramics, electrostrictive ceramics, posistor ceramics, superconductive ceramics and ferromagnetic ceramics. New possibilities of application of the perovskite-type ceramics are opened by nanotechnology. (author)

  8. Challenges for Insertion of Structural Nanomaterials in Aerospace Applications

    Science.gov (United States)

    Sochi, Emilie J.

    2012-01-01

    In the two decades since Iijima's report on carbon nanotubes (CNT), there has been great interest in realizing the benefits of mechanical properties observed at the nanoscale in large-scale structures. The weight savings possible due to dramatic improvements in mechanical properties relative to state-of-the-art material systems can be game changing for applications like aerospace vehicles. While there has been significant progress in commercial production of CNTs, major aerospace applications that take advantage of properties offered by this material have yet to be realized. This paper provides a perspective on the technical challenges and barriers for insertion of CNTs as an emerging material technology in aerospace applications and proposes approaches that may reduce the typical timeframe for technology maturation and insertion into aerospace structures.

  9. Low-Dimensional Nano structures for Optoelectronic Applications

    International Nuclear Information System (INIS)

    Lei, W.; Faraone, L.; Hoe Tan, H.; Lu, W.

    2014-01-01

    In recent years, low-dimensional (zero-, one-, and two-dimensional) nano structures have attracted wide attention and become a focus of scientific research and engineering application. This is due to their novel physical and chemical properties caused by size and quantum effects, as well as potential applications in various kinds of devices, for example, optoelectronics, nano electronics, and so forth. This special issue is intended to bring the most recent advances in the field of low-dimensional nano structures for optoelectronic applications. As expected, the research articles in this special issue cover a wide range of topics in this research field, ranging from theoretical simulation to material synthesis, to material characterization, to device fabrication, and to device characterization

  10. Biomedical application of hierarchically built structures based on metal oxides

    Science.gov (United States)

    Korovin, M. S.; Fomenko, A. N.

    2017-12-01

    Nowadays, the use of hierarchically built structures in biology and medicine arouses much interest. The aim of this work is to review and summarize the available literature data about hierarchically organized structures in biomedical application. Nanoparticles can serve as an example of such structures. Medicine holds a special place among various application methods of similar systems. Special attention is paid to inorganic nanoparticles based on different metal oxides and hydroxides, such as iron, zinc, copper, and aluminum. Our investigations show that low-dimensional nanostructures based on aluminum oxides and hydroxides have an inhibitory effect on tumor cells and possess an antimicrobial activity. At the same time, it is obvious that the large-scale use of nanoparticles by humans needs to thoroughly study their properties. Special attention should be paid to the study of nanoparticle interaction with living biological objects. The numerous data show that there is no clear understanding of interaction mechanisms between nanoparticles and various cell types.

  11. Requirements of Inconel 718 alloy for aeronautical applications

    Science.gov (United States)

    Ghiban, Brandusa; Elefterie, Cornelia Florina; Guragata, Constantin; Bran, Dragos

    2018-02-01

    The main requirements imposed by aviation components made from super alloys based on Nickel are presented in present paper. A significant portion of fasteners, locking lugs, blade retainers and inserts are manufactured from Inconel 718 alloy. The thesis describes environmental factors (corrosion), conditions of external aggression (salt air, intense heat, heavy industrial pollution, high condensation, high pressure), mechanical characteristics (tensile strength, creep, density, yield strength, fracture toughness, fatigue resistance) and loadings (tensions, compression loads) that must be satisfied simultaneously by Ni-based super alloy, compared to other classes of aviation alloys (as egg. Titanium alloys, Aluminum alloys). For this alloy the requirements are strength, durability, damage tolerance, fail safety and so on. The corrosion can be an issue, but the fatigue under high-magnitude cyclic tensile loading it what limits the lifetime of the airframe. The excellent malleability and weldability characteristics of the 718 system make the material physical properties tolerant of manufacturing processes. These characteristics additionally continue to provide new opportunities for advanced manufacturing methods.

  12. Spiral Antenna-Coupled Microbridge Structures for THz Application.

    Science.gov (United States)

    Gou, Jun; Zhang, Tian; Wang, Jun; Jiang, Yadong

    2017-12-01

    Bolometer sensor is a good candidate for THz imaging due to its compact system, low cost, and wideband operation. Based on infrared microbolometer structures, two kinds of antenna-coupled microbridge structures are proposed with different spiral antennas: spiral antenna on support layer and spiral antenna with extended legs. Aiming at applications in detection and imaging, simulations are carried out mainly for optimized absorption at 2.52 THz, which is the radiation frequency of far-infrared CO 2 lasers. The effects of rotation angle, line width, and spacing of the spiral antenna on THz wave absorption of microbridge structures are discussed. Spiral antenna, with extended legs, is a good solution for high absorption rate at low absorption frequency and can be used as electrode lead simultaneously for simplified manufacturing process. A spiral antenna-coupled microbridge structure with an absorption rate of more than 75% at 2.52 THz is achieved by optimizing the structure parameters. This research demonstrates the use of different spiral antennas for enhanced and tunable THz absorption of microbridge structures and provides an effective way to fabricate THz microbolometer detectors with great potential in the application of real-time THz imaging.

  13. NASA Ames Sustainability Initiatives: Aeronautics, Space Exploration, and Sustainable Futures

    Science.gov (United States)

    Grymes, Rosalind A.

    2015-01-01

    In support of the mission-specific challenges of aeronautics and space exploration, NASA Ames produces a wealth of research and technology advancements with significant relevance to larger issues of planetary sustainability. NASA research on NexGen airspace solutions and its development of autonomous and intelligent technologies will revolutionize both the nation's air transporation systems and have applicability to the low altitude flight economy and to both air and ground transporation, more generally. NASA's understanding of the Earth as a complex of integrated systems contributes to humanity's perception of the sustainability of our home planet. Research at NASA Ames on closed environment life support systems produces directly applicable lessons on energy, water, and resource management in ground-based infrastructure. Moreover, every NASA campus is a 'city'; including an urbanscape and a workplace including scientists, human relations specialists, plumbers, engineers, facility managers, construction trades, transportation managers, software developers, leaders, financial planners, technologists, electricians, students, accountants, and even lawyers. NASA is applying the lessons of our mission-related activities to our urbanscapes and infrastructure, and also anticipates a leadership role in developing future environments for living and working in space.

  14. Sectoral Innovation Watch Space and Aeronautics Sectors. Final sector report

    NARCIS (Netherlands)

    Giessen, A.M. van der

    2011-01-01

    The space and aeronautics sectors are high-technology sectors and belong to the most innovative sectors in Europe1. Analysis of CIS4 data shows that the space and aeronautics sectors continue to be very innovative. 85% of the firms is engaged in intramural R&D. Total R&D expenditures are between 21%

  15. 76 FR 183 - NASA Advisory Council; Aeronautics Committee; Meeting

    Science.gov (United States)

    2011-01-03

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice: (10-172)] NASA Advisory Council... the NASA Advisory Council. The meeting will be held for the purpose of soliciting from the aeronautics... 20546, (202) 358-0566, or [email protected]nasa.gov . SUPPLEMENTARY INFORMATION: The meeting will be open...

  16. Design and analysis of composite structures with applications to aerospace structures

    CERN Document Server

    Kassapoglou, Christos

    2010-01-01

    Design and Analysis of Composite Structures enables graduate students and engineers to generate meaningful and robust designs of complex composite structures. Combining analysis and design methods for structural components, the book begins with simple topics such as skins and stiffeners and progresses through to entire components of fuselages and wings. Starting with basic mathematical derivation followed by simplifications used in real-world design, Design and Analysis of Composite Structures presents the level of accuracy and range of applicability of each method. Examples taken from ac

  17. Shape tuning of adaptive structures for MEMS actuator applications

    Science.gov (United States)

    Ma, Zhichun; Lee, Yung-Cheng

    2005-05-01

    This paper describes a systematic shape tuning procedure of adaptive structures for MEMS actuator applications. Due to fabrication process variations, MEMS devices can have different shapes with varied deflections. Such shape variations should be corrected for specific applications. As a result, it is necessary to establish a shape tuning procedure. Finite element modeling and optimization approach were used to minimize the shape variations. The procedure integrated Python programming, ABAQUS, and optimization algorithm for engineering applications. It used the powerful Python scripts programming, the vast library of ABAQUS functions, and a robust preexisting optimization algorithm, NLPQL, which provides more efficient, flexible, and systematic tools for optimization problems. Optimization was used in the adaptive structural designs and the shape tuning procedure after the assembly. Using this approach, three bimorph, gold-on-polysilicon, samples with different initial shapes were studied for shape tuning. The shape was characterized by maximum tip deflection resulting from thermo-mechanical deformations. The standard deviation of the shape variations was reduced from 1.21 to 0.05 μm after tuning. This reduction was verified by experimental data. Another case with ten devices was studied to confirm the effectiveness of the procedure. The standard deviation of the deflections was reduced from 0.81 to 0.02 μm after tuning. These results demonstrated the effectiveness of the optimum procedure for shape tuning. This general-purpose systematic methodology can be applied to adaptive structures for a variety of aerospace applications.

  18. Applications of the Cambridge Structural Database in chemical education.

    Science.gov (United States)

    Battle, Gary M; Ferrence, Gregory M; Allen, Frank H

    2010-10-01

    The Cambridge Structural Database (CSD) is a vast and ever growing compendium of accurate three-dimensional structures that has massive chemical diversity across organic and metal-organic compounds. For these reasons, the CSD is finding significant uses in chemical education, and these applications are reviewed. As part of the teaching initiative of the Cambridge Crystallographic Data Centre (CCDC), a teaching subset of more than 500 CSD structures has been created that illustrate key chemical concepts, and a number of teaching modules have been devised that make use of this subset in a teaching environment. All of this material is freely available from the CCDC website, and the subset can be freely viewed and interrogated using WebCSD, an internet application for searching and displaying CSD information content. In some cases, however, the complete CSD System is required for specific educational applications, and some examples of these more extensive teaching modules are also discussed. The educational value of visualizing real three-dimensional structures, and of handling real experimental results, is stressed throughout.

  19. Special Issue: Adaptive/Smart Structures and Multifunctional Materials with Application to Morphing Aircraft

    Directory of Open Access Journals (Sweden)

    Rafic Ajaj

    2014-12-01

    Full Text Available Recent advances in smart structures and multifunctional materials have facilitated many novel aerospace technologies such as morphing aircraft. A morphing aircraft, bio-inspired by natural fliers, has gained a lot of interest as a potential technology to meet the ambitious goals of the Advisory Council for Aeronautics Research in Europe (ACARE Vision 2020 and the FlightPath 2050 documents. A morphing aircraft continuously adjusts its wing geometry to enhance flight performance, control authority, and multi-mission capability.[...

  20. 77 FR 32699 - NASA Advisory Council; Aeronautics Committee; UAS Subcommittee Meeting

    Science.gov (United States)

    2012-06-01

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice 12-039] NASA Advisory Council; Aeronautics Committee; UAS Subcommittee Meeting AGENCY: National Aeronautics and Space Administration. ACTION: Notice of..., the National Aeronautics and Space Administration (NASA) announces a meeting of the Unmanned Aircraft...

  1. Stochastic collocation-based finite element of structural nonlinear dynamics with application in composite structures

    Directory of Open Access Journals (Sweden)

    Sepahvand K.

    2016-01-01

    Full Text Available Stochastic analysis of structures having nonlinearity by means of sampling methods leads to expensive cost in term of computational time. In contrast, non-sampling methods based on the spectral representation of uncertainty are very efficient with comparable accurate results. In this pa- per, the application of spectral methods to nonlinear dynamics of structures with random parameters is investigated. The impact of the parameter randomness on structural responses has been consid- ered. To this end, uncertain parameters and the structure responses are represented using the gPC expansions with unknown deterministic coefficients and random orthogonal polynomial basis. The deterministic finite element model of the structure is used as black-box and it is executed on a set of random collocation points. As the sample structure responses are estimated, a nonlinear optimization process is employed to calculate the unknown coefficients. The method has this main advantage that can be used for complicated nonlinear structural dynamic problems for which the deterministic FEM model has been already developed. Furthermore, it is very time efficient in comparison with sampling methods, as MC simulations. The application of the method is applied to the nonlinear transient analysis of composite beam structures including uncertain quadratic random damping. The results show that the proposed method can capture the large range of uncertainty in input parameters as well as in structural dynamic responses while it is too time-efficient.

  2. Polarimetric and Interferometric Synthetic Aperture Radar ; a new way to quantify three-dimensional structure of Earth and planetary surfaces

    Data.gov (United States)

    National Aeronautics and Space Administration — The PolInSAR technique is designed to greatly improve estimates of forest biomass and ecosystem 3D structure . This application is also of special interest in the...

  3. An analysis of total quality management in Aeronautical Systems Division

    Science.gov (United States)

    Caudle, Mark D.

    1991-09-01

    This study investigated the major schools of thought on various aspects of quality management and quality improvement. Areas covered included definitions of waste and quality, views on the cost of quality, tools and techniques used for quality improvement, and management philosophies and frameworks for continuous improvement. In addition, this study analyzed the structure and training content of the current Total Quality Management program at Aeronautical Systems Division (ASD). Pre- and post-test surveys on employee attitudes toward organizational effectiveness were analyzed from the Advanced Cruise Missile System Program Office (SPO), the F-15 SPO, and the ASD Deputy Chief of Staff for Human Resources (ASD/DP). Data was supplemented with semi-structured, personal interviews with ASD personnel involved in TQM. Survey analysis showed that the ACM SPO significantly improved, ASD/DP significantly digressed, and the F-15 SPO remained basically consistent. This led to the conclusion that ASD allows too much flexibility in the implementation of TQM in the three-letter organizations.

  4. Composite corrugated structures for morphing wing skin applications

    International Nuclear Information System (INIS)

    Thill, C; Etches, J A; Bond, I P; Potter, K D; Weaver, P M

    2010-01-01

    Composite corrugated structures are known for their anisotropic properties. They exhibit relatively high stiffness parallel (longitudinal) to the corrugation direction and are relatively compliant in the direction perpendicular (transverse) to the corrugation. Thus, they offer a potential solution for morphing skin panels (MSPs) in the trailing edge region of a wing as a morphing control surface. In this paper, an overview of the work carried out by the present authors over the last few years on corrugated structures for morphing skin applications is first given. The second part of the paper presents recent work on the application of corrugated sandwich structures. Panels made from multiple unit cells of corrugated sandwich structures are used as MSPs in the trailing edge region of a scaled morphing aerofoil section. The aerofoil section features an internal actuation mechanism that allows chordwise length and camber change of the trailing edge region (aft 35% chord). Wind tunnel testing was carried out to demonstrate the MSP concept but also to explore its limitations. Suggestions for improvements arising from this study were deduced, one of which includes an investigation of a segmented skin. The overall results of this study show that the MSP concept exploiting corrugated sandwich structures offers a potential solution for local morphing wing skins for low speed and small air vehicles

  5. 206 Aerobasics–An Introduction to Aeronautics

    Indian Academy of Sciences (India)

    IAS Admin

    The Airplane Structure. S P Govinda Raju. GENERAL ARTICLES. 223. Xylem Hydraulics: Rising Up and Higher! Dilip Amritphale and Santosh K Sharma. 232. Mahlburg's Work on Crank Functions. Ramanujan's Partitions Revisited. Nagesh Juluru and Arni S R Srinivasa Rao. REFLECTIONS. 268. The Scientific Enterprise.

  6. High-performance insulator structures for accelerator applications

    International Nuclear Information System (INIS)

    Sampayan, S.E.; Caporaso, G.J.; Sanders, D.M.; Stoddard, R.D.; Trimble, D.O.; Elizondo, J.; Krogh, M.L.; Wieskamp, T.F.

    1997-05-01

    A new, high gradient insulator technology has been developed for accelerator systems. The concept involves the use of alternating layers of conductors and insulators with periods of order 1 mm or less. These structures perform many times better (about 1.5 to 4 times higher breakdown electric field) than conventional insulators in long pulse, short pulse, and alternating polarity applications. We describe our ongoing studies investigating the degradation of the breakdown electric field resulting from alternate fabrication techniques, the effect of gas pressure, the effect of the insulator-to-electrode interface gap spacing, and the performance of the insulator structure under bi-polar stress

  7. Metal Oxide Nano structures: Synthesis, Properties, and Applications

    International Nuclear Information System (INIS)

    Xu, L. H.; Patil, D. S.; Yang, J.; Xiao, J.

    2015-01-01

    In recent years, nano structured materials have attracted wide attention due to their fascinating optical and electrical properties, which make these materials potentially suitable for applications in electronics, optics, photonics, and sensors. Some metal oxides show a wide variety of morphologies such as nano wires, nano rods, nano tubes, nano rings, and nano belts. Synthesis and investigation of these metal-oxide nano structures are beneficial not only for understanding the fundamental phenomena in low dimensional systems, but also for developing new-generation nano devices with high performance.

  8. Linearly Polarized IR Spectroscopy Theory and Applications for Structural Analysis

    CERN Document Server

    Kolev, Tsonko

    2011-01-01

    A technique that is useful in the study of pharmaceutical products and biological molecules, polarization IR spectroscopy has undergone continuous development since it first emerged almost 100 years ago. Capturing the state of the science as it exists today, "Linearly Polarized IR Spectroscopy: Theory and Applications for Structural Analysis" demonstrates how the technique can be properly utilized to obtain important information about the structure and spectral properties of oriented compounds. The book starts with the theoretical basis of linear-dichroic infrared (IR-LD) spectroscop

  9. The structure of complex networks theory and applications

    CERN Document Server

    Estrada, Ernesto

    2012-01-01

    This book deals with the analysis of the structure of complex networks by combining results from graph theory, physics, and pattern recognition. The book is divided into two parts. 11 chapters are dedicated to the development of theoretical tools for the structural analysis of networks, and 7 chapters are illustrating, in a critical way, applications of these tools to real-world scenarios. The first chapters provide detailed coverage of adjacency and metric and topologicalproperties of networks, followed by chapters devoted to the analysis of individual fragments and fragment-based global inva

  10. Structural Applications of Fibre Reinforced Concrete in the Czech Republic

    Science.gov (United States)

    Kohoutková, A.; Broukalová, I.

    2017-09-01

    The paper presents improvement of function and performance of the precast structural members by using fibre reinforced concrete (FRC) instead of ordinary reinforced concrete and attempts to transfer innovative technologies from laboratory in academic sphere into real industrial production which is cost-effective and brings about savings of labour and material. Three examples of successful technology transfer are shown - application of FRC in an element without common rebar reinforcement, in the element with steel rebar reinforcement and SFRC pre-tensioned structural element. Benefits of FRC utilization are discussed.

  11. Applications in soil-structure interactions. Final report, June 1979

    International Nuclear Information System (INIS)

    Jhaveri, D.P.

    1979-01-01

    Complex phenomenon of soil-structure interaction was assessed. Relationships between the characteristics of the earthquake ground motions, the local soil and geologic conditions, and the response of the structures to the ground motions were studied. (I) The use of the explicit finite-difference method to study linear elastic soil-structure interaction is described. A linear two-dimensional study of different conditions that influence the dynamic compliance and scattering properties of foundations is presented. (II) The FLUSH computer code was used to compute the soil-structure interaction during SIMQUAKE 1B, an experimental underground blast excitation of a 1/12-scale model of a nuclear containment structure. Evaluation was performed using transient excitation, applied to a finite-difference grid. Dynamic foundation properties were studied. Results indicate that the orientation and location of the source relative to the site and the wave environment at the site may be important parameters to be considered. Differences between the computed and experimental recorded responses are indicated, and reasons for the discrepancy are suggested. (III) A case study that examined structural and ground response data tabulated and catalogued from tests at the Nevada Test Site for its applicability to the soil-structure interaction questions of interest is presented. Description, methods, and evaluation of data on soil-structure interaction from forced vibration tests are presented. A two-dimensional finite-difference grid representing a relatively rigid structure resting on uniform ground was analyzed and monitored. Fourier spectra of monitored time histories were also evaluated and are presented. Results show clear evidence of soil-structure interaction and significant agreement with theory. 128 figures, 18 tables

  12. Algebraic Modeling of Topological and Computational Structures and Applications

    CERN Document Server

    Theodorou, Doros; Stefaneas, Petros; Kauffman, Louis

    2017-01-01

    This interdisciplinary book covers a wide range of subjects, from pure mathematics (knots, braids, homotopy theory, number theory) to more applied mathematics (cryptography, algebraic specification of algorithms, dynamical systems) and concrete applications (modeling of polymers and ionic liquids, video, music and medical imaging). The main mathematical focus throughout the book is on algebraic modeling with particular emphasis on braid groups. The research methods include algebraic modeling using topological structures, such as knots, 3-manifolds, classical homotopy groups, and braid groups. The applications address the simulation of polymer chains and ionic liquids, as well as the modeling of natural phenomena via topological surgery. The treatment of computational structures, including finite fields and cryptography, focuses on the development of novel techniques. These techniques can be applied to the design of algebraic specifications for systems modeling and verification. This book is the outcome of a w...

  13. Code Development for Control Design Applications: Phase I: Structural Modeling

    International Nuclear Information System (INIS)

    Bir, G. S.; Robinson, M.

    1998-01-01

    The design of integrated controls for a complex system like a wind turbine relies on a system model in an explicit format, e.g., state-space format. Current wind turbine codes focus on turbine simulation and not on system characterization, which is desired for controls design as well as applications like operating turbine model analysis, optimal design, and aeroelastic stability analysis. This paper reviews structural modeling that comprises three major steps: formation of component equations, assembly into system equations, and linearization

  14. Requirements of titanium alloys for aeronautical industry

    Science.gov (United States)

    Ghiban, Brânduşa; Bran, Dragoş-Teodor; Elefterie, Cornelia Florina

    2018-02-01

    The project presents the requirements imposed for aeronatical components made from Titanium based alloys. Asignificant portion of the aircraft pylons are manufactured from Titanium alloys. Strength, weight, and reliability are the primary factors to consider in aircraft structures. These factors determine the requirements to be met by any material used to construct or repair the aircraft. Many forces and structural stresses act on an aircraft when it is flying and when it is static and this thesis describes environmental factors, conditions of external aggression, mechanical characteristics and loadings that must be satisfied simultaneously by a Ti-based alloy, compared to other classes of aviation alloys (as egg. Inconel super alloys, Aluminum alloys). For this alloy class, the requirements are regarding strength to weight ratio, reliability, corrosion resistance, thermal expansion and so on. These characteristics additionally continue to provide new opportunities for advanced manufacturing methods.

  15. Aeronautical Industry Requirements for Titanium Alloys

    Science.gov (United States)

    Bran, D. T.; Elefterie, C. F.; Ghiban, B.

    2017-06-01

    The project presents the requirements imposed for aviation components made from Titanium based alloys. A significant portion of the aircraft pylons are manufactured from Titanium alloys. Strength, weight, and reliability are the primary factors to consider in aircraft structures. These factors determine the requirements to be met by any material used to construct or repair the aircraft. Many forces and structural stresses act on an aircraft when it is flying and when it is static and this thesis describes environmental factors, conditions of external aggression, mechanical characteristics and loadings that must be satisfied simultaneously by a Ti-based alloy, compared to other classes of aviation alloys (as egg. Inconel super alloys, Aluminum alloys).For this alloy class, the requirements are regarding strength to weight ratio, reliability, corrosion resistance, thermal expansion and so on. These characteristics additionally continue to provide new opportunities for advanced manufacturing methods.

  16. Lipids: From Chemical Structures, Biosynthesis, and Analyses to Industrial Applications.

    Science.gov (United States)

    Li-Beisson, Yonghua; Nakamura, Yuki; Harwood, John

    2016-01-01

    Lipids are one of the major subcellular components, and play numerous essential functions. As well as their physiological roles, oils stored in biomass are useful commodities for a variety of biotechnological applications including food, chemical feedstocks, and fuel. Due to their agronomic as well as economic and societal importance, lipids have historically been subjected to intensive studies. Major current efforts are to increase the energy density of cell biomass, and/or create designer oils suitable for specific applications. This chapter covers some basic aspects of what one needs to know about lipids: definition, structure, function, metabolism and focus is also given on the development of modern lipid analytical tools and major current engineering approaches for biotechnological applications. This introductory chapter is intended to serve as a primer for all subsequent chapters in this book outlining current development in specific areas of lipids and their metabolism.

  17. Low-Cost Composite Materials and Structures for Aircraft Applications

    Science.gov (United States)

    Deo, Ravi B.; Starnes, James H., Jr.; Holzwarth, Richard C.

    2003-01-01

    A survey of current applications of composite materials and structures in military, transport and General Aviation aircraft is presented to assess the maturity of composites technology, and the payoffs realized. The results of the survey show that performance requirements and the potential to reduce life cycle costs for military aircraft and direct operating costs for transport aircraft are the main reasons for the selection of composite materials for current aircraft applications. Initial acquisition costs of composite airframe components are affected by high material costs and complex certification tests which appear to discourage the widespread use of composite materials for aircraft applications. Material suppliers have performed very well to date in developing resin matrix and fiber systems for improved mechanical, durability and damage tolerance performance. The next challenge for material suppliers is to reduce material costs and to develop materials that are suitable for simplified and inexpensive manufacturing processes. The focus of airframe manufacturers should be on the development of structural designs that reduce assembly costs by the use of large-scale integration of airframe components with unitized structures and manufacturing processes that minimize excessive manual labor.

  18. A Hybrid Satellite-Terrestrial Approach to Aeronautical Communication Networks

    Science.gov (United States)

    Kerczewski, Robert J.; Chomos, Gerald J.; Griner, James H.; Mainger, Steven W.; Martzaklis, Konstantinos S.; Kachmar, Brian A.

    2000-01-01

    Rapid growth in air travel has been projected to continue for the foreseeable future. To maintain a safe and efficient national and global aviation system, significant advances in communications systems supporting aviation are required. Satellites will increasingly play a critical role in the aeronautical communications network. At the same time, current ground-based communications links, primarily very high frequency (VHF), will continue to be employed due to cost advantages and legacy issues. Hence a hybrid satellite-terrestrial network, or group of networks, will emerge. The increased complexity of future aeronautical communications networks dictates that system-level modeling be employed to obtain an optimal system fulfilling a majority of user needs. The NASA Glenn Research Center is investigating the current and potential future state of aeronautical communications, and is developing a simulation and modeling program to research future communications architectures for national and global aeronautical needs. This paper describes the primary requirements, the current infrastructure, and emerging trends of aeronautical communications, including a growing role for satellite communications. The need for a hybrid communications system architecture approach including both satellite and ground-based communications links is explained. Future aeronautical communication network topologies and key issues in simulation and modeling of future aeronautical communications systems are described.

  19. A nonlinear cointegration approach with applications to structural health monitoring

    Science.gov (United States)

    Shi, H.; Worden, K.; Cross, E. J.

    2016-09-01

    One major obstacle to the implementation of structural health monitoring (SHM) is the effect of operational and environmental variabilities, which may corrupt the signal of structural degradation. Recently, an approach inspired from the community of econometrics, called cointegration, has been employed to eliminate the adverse influence from operational and environmental changes and still maintain sensitivity to structural damage. However, the linear nature of cointegration may limit its application when confronting nonlinear relations between system responses. This paper proposes a nonlinear cointegration method based on Gaussian process regression (GPR); the method is constructed under the Engle-Granger framework, and tests for unit root processes are conducted both before and after the GPR is applied. The proposed approach is examined with real engineering data from the monitoring of the Z24 Bridge.

  20. Application of anti-reflection structures on curved surfaces

    Science.gov (United States)

    Yamamoto, Kazuya; Yamamoto, Takeshi; Takaoka, Toshimitsu; Seigo, Masafumi; Kitagawa, Seiichiro

    2012-02-01

    Conventional lens manufacturing is accomplished by injection molding followed by application of a thin film anti-reflection coating. This requires several production steps, each with the associated constraints. Here we report a technique for production of injection molded lenses with conical sub-wavelength grating anti-reflection structures. While similar structures have been made in the past, our technique allows the sub-wavelength structure to be created on curved surfaces during the injection molding process, reducing the number of steps in the manufacturing process. The advantage of this new technology is that anti-reflection function is created without any additional process(es) conventionally required but by a single injection molding process to make lens normally, through which substantial cost saving will be achieved.

  1. An Overview of the NASA Aeronautics Test Program Strategic Plan

    Science.gov (United States)

    Marshall, Timothy J.

    2010-01-01

    U.S. leadership in aeronautics depends on ready access to technologically advanced, efficient, and affordable aeronautics test capabilities. These systems include major wind tunnels and propulsion test facilities and flight test capabilities. The federal government owns the majority of the major aeronautics test capabilities in the United States, primarily through the National Aeronautics and Space Administration (NASA) and the Department of Defense (DoD), however an overarching strategy for management of these national assets was needed. Therefore, in Fiscal Year (FY) 2006 NASA established the Aeronautics Test Program (ATP) as a two-pronged strategic initiative to: (1) retain and invest in NASA aeronautics test capabilities considered strategically important to the agency and the nation, and (2) establish a strong, high level partnership with the DoD Test Resources Management Center (TRMC), stewards of the DoD test and evaluation infrastructure. Since then, approximately seventy percent of the ATP budget has been directed to underpin fixed and variable costs of facility operations within its portfolio and the balance towards strategic investments in its test facilities, including maintenance and capability upgrades. Also, a strong guiding coalition was established through the National Partnership for Aeronautics Testing (NPAT), with governance by the senior leadership of NASA s Aeronautics Research Mission Directorate (ARMD) and the DoD's TRMC. As part of its strategic planning, ATP has performed or participated in many studies and analyses, including assessments of major NASA and DoD aeronautics test capabilities, test facility condition evaluations and market research. The ATP strategy has also benefitted from unpublished RAND research and analysis by Ant n et al. (2009). Together, these various studies, reports and assessments serve as a foundation for a new, five year strategic plan that will guide ATP through FY 2014. Our vision for the future is a balanced

  2. Laser deposition of coatings for aeronautical and industrials turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Teleginski, V. [Instituto Federal de Sao Paulo (IFSP), SP (Brazil); Silva, S.A.; Riva, R.; Vasconcelos, G. [Instituto de Estudos Avancados (IEAv), Sao Jose dos Campos, SP (Brazil); Silva Pita, G.R. [Universidade Braz Cubas, Mogi das Cruzes, SP (Brazil); Yamin, L.S. [Escola Tecnica Everardo Passos (ETEP), Sao Jose dos Campos, DP (Brazil)

    2016-07-01

    Full text: Zirconium-based ceramic materials are widely employed as Thermal Barrier Coatings (TBC), due to its excellent wear and corrosion resistance at high temperatures. The application of TBC includes aeronautical and industrials turbine blades. The working conditions include oxidizing environments and temperatures above 1000°C. The zirconium-based ceramics are developed in such a way that the microstructural control is possible through the control of chemical composition, fabrication route and, thermal treatment. The present paper proposes a laser route to deposit the TBC coating, where the microstructural control is a function of power density and interaction time between the laser beam and the material. The main objective of this work is to study the influence of the CO2 laser beam (Synrad Evolution 125) parameters: power density and interaction time, on the deposition process of yttria-stabilized zirconia (YSZ) powders on NiCrAlY/AISI 316L substrates. The resulting coating surface and interface were characterized by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. The results indicate that is possible to match laser parameters of scanning speed and intensity to produce homogenous coatings. The X-Ray analyses show that the obtained ceramic coating has reduced number of phases, with prevalence of tetragonal phase.(author)

  3. Structural Design Challenges in Design Certification Applications for New Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, M.; Braverman, J.; Wei, X.; Hofmayer, C.; Xu, J.

    2011-07-17

    The licensing framework established by the U.S. Nuclear Regulatory Commission under Title 10 of the Code of Federal Regulations (10 CFR) Part 52, “Licenses, Certifications, and Approvals for Nuclear Power Plants,” provides requirements for standard design certifications (DCs) and combined license (COL) applications. The intent of this process is the early reso- lution of safety issues at the DC application stage. Subsequent COL applications may incorporate a DC by reference. Thus, the COL review will not reconsider safety issues resolved during the DC process. However, a COL application that incorporates a DC by reference must demonstrate that relevant site-specific de- sign parameters are confined within the bounds postulated by the DC, and any departures from the DC need to be justified. This paper provides an overview of structural design chal- lenges encountered in recent DC applications under the 10 CFR Part 52 process, in which the authors have participated as part of the safety review effort.

  4. Fibre Optic Sensors for Structural Health Monitoring of Aircraft Composite Structures: Recent Advances and Applications.

    Science.gov (United States)

    Di Sante, Raffaella

    2015-07-30

    In-service structural health monitoring of composite aircraft structures plays a key role in the assessment of their performance and integrity. In recent years, Fibre Optic Sensors (FOS) have proved to be a potentially excellent technique for real-time in-situ monitoring of these structures due to their numerous advantages, such as immunity to electromagnetic interference, small size, light weight, durability, and high bandwidth, which allows a great number of sensors to operate in the same system, and the possibility to be integrated within the material. However, more effort is still needed to bring the technology to a fully mature readiness level. In this paper, recent research and applications in structural health monitoring of composite aircraft structures using FOS have been critically reviewed, considering both the multi-point and distributed sensing techniques.

  5. Fibre Optic Sensors for Structural Health Monitoring of Aircraft Composite Structures: Recent Advances and Applications

    Directory of Open Access Journals (Sweden)

    Raffaella Di Sante

    2015-07-01

    Full Text Available In-service structural health monitoring of composite aircraft structures plays a key role in the assessment of their performance and integrity. In recent years, Fibre Optic Sensors (FOS have proved to be a potentially excellent technique for real-time in-situ monitoring of these structures due to their numerous advantages, such as immunity to electromagnetic interference, small size, light weight, durability, and high bandwidth, which allows a great number of sensors to operate in the same system, and the possibility to be integrated within the material. However, more effort is still needed to bring the technology to a fully mature readiness level. In this paper, recent research and applications in structural health monitoring of composite aircraft structures using FOS have been critically reviewed, considering both the multi-point and distributed sensing techniques.

  6. Fibre Optic Sensors for Structural Health Monitoring of Aircraft Composite Structures: Recent Advances and Applications

    Science.gov (United States)

    Di Sante, Raffaella

    2015-01-01

    In-service structural health monitoring of composite aircraft structures plays a key role in the assessment of their performance and integrity. In recent years, Fibre Optic Sensors (FOS) have proved to be a potentially excellent technique for real-time in-situ monitoring of these structures due to their numerous advantages, such as immunity to electromagnetic interference, small size, light weight, durability, and high bandwidth, which allows a great number of sensors to operate in the same system, and the possibility to be integrated within the material. However, more effort is still needed to bring the technology to a fully mature readiness level. In this paper, recent research and applications in structural health monitoring of composite aircraft structures using FOS have been critically reviewed, considering both the multi-point and distributed sensing techniques. PMID:26263987

  7. Novel thermal management structures and their applications in new hybrid technologies and feed-through structures

    International Nuclear Information System (INIS)

    Carter, A.A.; Oliveira, R. de; Gandi, A.

    1999-01-01

    Novel techniques are described for fabricating a new thermal management structure (TMS), in the form of rigid low-mass structures with extremely high in-plane thermal conductivity. The core materials can be forms of thermally anisotropically conducting pyrolytic graphite that are directly encapsulated in a new thin-layering process. The structures can be used in a large variety of applications, including: (a) Efficient interfacing with ceramic materials and metals to provide new thermal management technologies. (b) Providing the source for a new hybrid technology where low-mass custom-designed multilayer thin-film circuits can be directly processed onto such structures. Alternatively, having been prefabricated on an independent substrate, hybrids can be efficiently interfaced to such thermal management structures. (c) Providing electrical connectivity between both sides of a TMS board through a new feedthrough technology that allows the fabrication of both single-sided and double-sided hybrids. These thermal management techniques and their applications are the subject of an international patent application number PCT/GB99/02180, filed in the names of the European Organization for Nuclear Research and Queen Mary and Westfield College, London. (orig.)

  8. MUSTANG-MR structural sieving server: applications in protein structural analysis and crystallography.

    Directory of Open Access Journals (Sweden)

    Arun S Konagurthu

    Full Text Available BACKGROUND: A central tenet of structural biology is that related proteins of common function share structural similarity. This has key practical consequences for the derivation and analysis of protein structures, and is exploited by the process of "molecular sieving" whereby a common core is progressively distilled from a comparison of two or more protein structures. This paper reports a novel web server for "sieving" of protein structures, based on the multiple structural alignment program MUSTANG. METHODOLOGY/PRINCIPAL FINDINGS: "Sieved" models are generated from MUSTANG-generated multiple alignment and superpositions by iteratively filtering out noisy residue-residue correspondences, until the resultant correspondences in the models are optimally "superposable" under a threshold of RMSD. This residue-level sieving is also accompanied by iterative elimination of the poorly fitting structures from the input ensemble. Therefore, by varying the thresholds of RMSD and the cardinality of the ensemble, multiple sieved models are generated for a given multiple alignment and superposition from MUSTANG. To aid the identification of structurally conserved regions of functional importance in an ensemble of protein structures, Lesk-Hubbard graphs are generated, plotting the number of residue correspondences in a superposition as a function of its corresponding RMSD. The conserved "core" (or typically active site shows a linear trend, which becomes exponential as divergent parts of the structure are included into the superposition. CONCLUSIONS: The application addresses two fundamental problems in structural biology: first, the identification of common substructures among structurally related proteins--an important problem in characterization and prediction of function; second, generation of sieved models with demonstrated uses in protein crystallographic structure determination using the technique of Molecular Replacement.

  9. MUSTANG-MR structural sieving server: applications in protein structural analysis and crystallography.

    Science.gov (United States)

    Konagurthu, Arun S; Reboul, Cyril F; Schmidberger, Jason W; Irving, James A; Lesk, Arthur M; Stuckey, Peter J; Whisstock, James C; Buckle, Ashley M

    2010-04-06

    A central tenet of structural biology is that related proteins of common function share structural similarity. This has key practical consequences for the derivation and analysis of protein structures, and is exploited by the process of "molecular sieving" whereby a common core is progressively distilled from a comparison of two or more protein structures. This paper reports a novel web server for "sieving" of protein structures, based on the multiple structural alignment program MUSTANG. "Sieved" models are generated from MUSTANG-generated multiple alignment and superpositions by iteratively filtering out noisy residue-residue correspondences, until the resultant correspondences in the models are optimally "superposable" under a threshold of RMSD. This residue-level sieving is also accompanied by iterative elimination of the poorly fitting structures from the input ensemble. Therefore, by varying the thresholds of RMSD and the cardinality of the ensemble, multiple sieved models are generated for a given multiple alignment and superposition from MUSTANG. To aid the identification of structurally conserved regions of functional importance in an ensemble of protein structures, Lesk-Hubbard graphs are generated, plotting the number of residue correspondences in a superposition as a function of its corresponding RMSD. The conserved "core" (or typically active site) shows a linear trend, which becomes exponential as divergent parts of the structure are included into the superposition. The application addresses two fundamental problems in structural biology: first, the identification of common substructures among structurally related proteins--an important problem in characterization and prediction of function; second, generation of sieved models with demonstrated uses in protein crystallographic structure determination using the technique of Molecular Replacement.

  10. Structural morphology of zinc oxide structures with antibacterial application of calamine lotion

    Energy Technology Data Exchange (ETDEWEB)

    Ann, Ling Chuo; Mahmud, Shahrom; Bakhori, Siti Khadijah Mohd; Sirelkhatim, Amna [Nano-optoelectronic Research (NOR) Laboratory, School of Physics, Universiti Sains Malaysia 11800 Pulau Pinang (Malaysia); Mohamad, Dasmawati [School of Dental Sciences, Universiti Sains Malaysia, Kubang Kerian 16150 Kelantan (Malaysia); Hasan, Habsah; Rahman, Rosliza Abdul [School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150 Kelantan (Malaysia); Seeni, Azman [Advanced Medical and Dental Institute, Universiti Sains Malaysia, Bertam 13200 Pulau Pinang (Malaysia)

    2015-04-24

    In this study, we report the structural morphology of a zinc oxide (ZnO) sample and antibacterial application of the ZnO structures in calamine lotion. Antibacterial activities of the calamine lotion towards Staphylococcus aureus and Pseudomonas aeruginosa were investigated. The structural morphology of ZnO sample was studied using a transmission electron microscope (TEM) and a field-emission scanning electron microscope (FESEM). The morphologies of the ZnO structure consisted of many rod and spherical structures. The particle sizes of the sample ranged from 40 nm to 150 nm. A calamine lotion was prepared through mixing the ZnO structures with other constituents in suitable proportion. The energy-dispersive x-ray spectroscopy (EDS) revealed the presence of large amount of ZnO structures whiles the X-ray diffraction (XRD) results showed a good crystalline property of ZnO in the calamine lotion mixture. The morphological structures of ZnO were found to remain unchanged in the calamine lotion mixture through FESEM imaging. In the antibacterial test, prepared calamine lotion exhibited a remarkable bacterial inhibition on Staphylococcus aureus and Pseudomonas aeruginosa after 24 h of treatment. The bactericidal capability of calamine lotion was largely due to the presence of ZnO structures which induce high toxicity and killing effect on the bacteria.

  11. Structural morphology of zinc oxide structures with antibacterial application of calamine lotion

    Science.gov (United States)

    Ann, Ling Chuo; Mahmud, Shahrom; Bakhori, Siti Khadijah Mohd; Sirelkhatim, Amna; Mohamad, Dasmawati; Hasan, Habsah; Seeni, Azman; Rahman, Rosliza Abdul

    2015-04-01

    In this study, we report the structural morphology of a zinc oxide (ZnO) sample and antibacterial application of the ZnO structures in calamine lotion. Antibacterial activities of the calamine lotion towards Staphylococcus aureus and Pseudomonas aeruginosa were investigated. The structural morphology of ZnO sample was studied using a transmission electron microscope (TEM) and a field-emission scanning electron microscope (FESEM). The morphologies of the ZnO structure consisted of many rod and spherical structures. The particle sizes of the sample ranged from 40 nm to 150 nm. A calamine lotion was prepared through mixing the ZnO structures with other constituents in suitable proportion. The energy-dispersive x-ray spectroscopy (EDS) revealed the presence of large amount of ZnO structures whiles the X-ray diffraction (XRD) results showed a good crystalline property of ZnO in the calamine lotion mixture. The morphological structures of ZnO were found to remain unchanged in the calamine lotion mixture through FESEM imaging. In the antibacterial test, prepared calamine lotion exhibited a remarkable bacterial inhibition on Staphylococcus aureus and Pseudomonas aeruginosa after 24 h of treatment. The bactericidal capability of calamine lotion was largely due to the presence of ZnO structures which induce high toxicity and killing effect on the bacteria.

  12. 76 FR 53530 - Government/Industry Aeronautical Charting Forum Meeting

    Science.gov (United States)

    2011-08-26

    ... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Government/Industry Aeronautical Charting Forum Meeting AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of public meeting. SUMMARY: This notice announces the bi-annual meeting of the Federal Aviation Administration (FAA...

  13. Applied simulation and optimization : in logistics, industrial and aeronautical practice

    NARCIS (Netherlands)

    Mujica Mota, Miguel; De la Mota, Idalia Flores; Guimarans Serrano, Daniel

    2015-01-01

    Presenting techniques, case-studies and methodologies that combine the use of simulation approaches with optimization techniques for facing problems in manufacturing, logistics, or aeronautical problems, this book provides solutions to common industrial problems in several fields, which range from

  14. National Aeronautics and Space Administration: Guidance for Improving Customer Satisfaction.

    Science.gov (United States)

    1994-04-01

    Executive Order 12862, Setting Customer Service Standards, requires that the National Aeronautics and Space Administration (NASA) undertake customer ... satisfaction surveys to obtain customer feedback for improving its products and service. It also requires that NASA search for best industry practices

  15. Kennedy Educate to Innovate (KETI) Aeronautics PowerPoint Presentation

    Science.gov (United States)

    Davila, Dina

    2010-01-01

    This slide presentation reviews some fundamental features of aeronautics. It is designed to introduce students to aeronautics and to engage them in Science Technology Education and Mathematics (STEM). It reviews the history of airflight, the aircraft components and their interaction with the forces that make flight possible (i.e. lift, weight drag and thrust), and the interaction of the components that create aircraft movements (roll, pitch and yaw)

  16. NASA Ames and Future of Space Exploration, Science, and Aeronautics

    Science.gov (United States)

    Cohen, Jacob

    2015-01-01

    Pushing the frontiers of aeronautics and space exploration presents multiple challenges. NASA Ames Research Center is at the forefront of tackling these issues, conducting cutting edge research in the fields of air traffic management, entry systems, advanced information technology, intelligent human and robotic systems, astrobiology, aeronautics, space, earth and life sciences and small satellites. Knowledge gained from this research helps ensure the success of NASA's missions, leading us closer to a world that was only imagined as science fiction just decades ago.

  17. Thermosetting polymer-matrix composites for structural repair applications

    Science.gov (United States)

    Goertzen, William Kirby

    2007-12-01

    Several classes of thermosetting polymer matrix composites were evaluated for use in structural repair applications. Initial work involved the characterization and evaluation of woven carbon fiber/epoxy matrix composites for structural pipeline repair. Cyanate ester resins were evaluated as a replacement for epoxy in composites for high-temperature pipe repair applications, and as the basis for adhesives for resin infusion repair of high-temperature composite materials. Carbon fiber/cyanate ester matrix composites and fumed silica/cyanate ester nanocomposites were evaluated for their thermal, mechanical, viscoelastic, and rheological properties as they relate to their structure, chemistry, and processing characteristics. The bisphenol E cyanate ester under investigation possesses a high glass transition temperature, excellent mechanical properties, and unique ambient temperature processability. The incorporation of fumed silica served to enhance the mechanical and rheological properties of the polymer and reduce thermal expansion without sacrificing glass transition or drastically altering curing kinetics. Characterization of the composites included dynamic mechanical analysis, thermomechanical analysis, differential scanning calorimetry, thermogravimetric analysis, rheological and rheokinetic evaluation, and transmission electron microscopy.

  18. Safety Risk Knowledge Elicitation in Support of Aeronautical R and D Portfolio Management: A Case Study

    Science.gov (United States)

    Shih, Ann T.; Ancel, Ersin; Jones, Sharon Monica; Reveley, Mary S.; Luxhoj, James T.

    2012-01-01

    Aviation is a problem domain characterized by a high level of system complexity and uncertainty. Safety risk analysis in such a domain is especially challenging given the multitude of operations and diverse stakeholders. The Federal Aviation Administration (FAA) projects that by 2025 air traffic will increase by more than 50 percent with 1.1 billion passengers a year and more than 85,000 flights every 24 hours contributing to further delays and congestion in the sky (Circelli, 2011). This increased system complexity necessitates the application of structured safety risk analysis methods to understand and eliminate where possible, reduce, and/or mitigate risk factors. The use of expert judgments for probabilistic safety analysis in such a complex domain is necessary especially when evaluating the projected impact of future technologies, capabilities, and procedures for which current operational data may be scarce. Management of an R&D product portfolio in such a dynamic domain needs a systematic process to elicit these expert judgments, process modeling results, perform sensitivity analyses, and efficiently communicate the modeling results to decision makers. In this paper a case study focusing on the application of an R&D portfolio of aeronautical products intended to mitigate aircraft Loss of Control (LOC) accidents is presented. In particular, the knowledge elicitation process with three subject matter experts who contributed to the safety risk model is emphasized. The application and refinement of a verbal-numerical scale for conditional probability elicitation in a Bayesian Belief Network (BBN) is discussed. The preliminary findings from this initial step of a three-part elicitation are important to project management practitioners as they illustrate the vital contribution of systematic knowledge elicitation in complex domains.

  19. Development and application of advanced methods for electronic structure calculations

    DEFF Research Database (Denmark)

    Schmidt, Per Simmendefeldt

    ground state energies, is used to calculate accurate adsorption energies for a wide range of reactions. The results are in good agreement with experimental values, where available. Additionally, a database consisting of 200 highly accurate adsorption energies is constructed to benchmark the accuracy......This thesis relates to improvements and applications of beyond-DFT methods for electronic structure calculations that are applied in computational material science. The improvements are of both technical and principal character. The well-known GW approximation is optimized for accurate calculations...... of electronic excitations in two-dimensional materials by exploiting exact limits of the screened Coulomb potential. This approach reduces the computational time by an order of magnitude, enabling large scale applications. The GW method is further improved by including so-called vertex corrections. This turns...

  20. Core/Shell Structured Magnetic Nanoparticles for Biological Applications

    International Nuclear Information System (INIS)

    Park, Jeong Chan; Jung, Myung Hwan

    2013-01-01

    Magnetic nanoparticles have been widely used for biomedical applications, such as magnetic resonance imaging (MRI), hyperthermia, drug delivery and cell signaling. The surface modification of the nanomaterials is required for biomedical use to give physiogical stability, surface reactivity and targeting properties. Among many approaches for the surface modification with materials, such as polymers, organic ligands and metals, one of the most attractive ways is using metals. The fabrication of metal-based, monolayer-coated magnetic nanoparticles has been intensively studied. However, the synthesis of metal-capped magnetic nanoparticles with monodispersities and controllable sizes is still challenged. Recently, gold-capped magnetic nanoparticles have been reported to increase stability and to provide biocompatibility. Magnetic nanoparticle with gold coating is an attractive system, which can be stabilized in biological conditions and readily functionalized in biological conditions and readily functionalized through well-established surface modification (Au-S) chemistry. The Au coating offers plasmonic properties to magnetic nanoparticles. This makes the magnetic/Au core/shell combinations interesting for magnetic and optical applications. Herein, the synthesis and characterization of gold capped-magnetic core structured nanomaterials with different gold sources, such as gold acetate and chloroauric acid have been reported. The core/shell nanoparticles were transferred from organic to aqueous solutions for biomedical applications. Magnetic core/shell structured nanoparticles have been prepared and transferred from organic phase to aqueous solutions. The resulting Au-coated magnetic core nanoparticles might be an attractive system for biomedical applications, which are needed both magnetic resonance imaging and optical imaging

  1. Block-structured Adaptive Mesh Refinement - Theory, Implementation and Application

    Directory of Open Access Journals (Sweden)

    Deiterding Ralf

    2011-12-01

    Full Text Available Structured adaptive mesh refinement (SAMR techniques can enable cutting-edge simulations of problems governed by conservation laws. Focusing on the strictly hyperbolic case, these notes explain all algorithmic and mathematical details of a technically relevant implementation tailored for distributed memory computers. An overview of the background of commonly used finite volume discretizations for gas dynamics is included and typical benchmarks to quantify accuracy and performance of the dynamically adaptive code are discussed. Large-scale simulations of shock-induced realistic combustion in non-Cartesian geometry and shock-driven fluid-structure interaction with fully coupled dynamic boundary motion demonstrate the applicability of the discussed techniques for complex scenarios.

  2. Structured Control of LPV Systems with Application to Wind Turbines

    DEFF Research Database (Denmark)

    Adegas, Fabiano Daher; Stoustrup, Jakob

    2012-01-01

    This paper deals with structured control of linear parameter varying systems (LPV) with application to wind turbines. Instead of attempting to reduce the problem to linear matrix inequalities (LMI), we propose to design the controllers via an LMI-based iterative algorithm. The proposed algorithm...... can synthesize structured controllers like decentralized, static output and reduced order output feedback for discrete-time LPV systems. Based on a coordinate decent, it relies on a sufficient matrix inequality condition extended with slack variables to an upper bound on the induced L2-norm...... of the closed-loop system. Algorithms for the computation of feasible as well as optimal controllers are presented. The general case where no restrictions are imposed on the parameter dependence is treated here due to its suitability for modeling wind turbines. A comprehensive numerical example of a gain...

  3. Microbial mat ecosystems: Structure types, functional diversity, and biotechnological application

    Directory of Open Access Journals (Sweden)

    Cristina M. Prieto-Barajas

    2018-01-01

    Full Text Available Microbial mats are horizontally stratified microbial communities, exhibiting a structure defined by physiochemical gradients, which models microbial diversity, physiological activities, and their dynamics as a whole system. These ecosystems are commonly associated with aquatic habitats, including hot springs, hypersaline ponds, and intertidal coastal zones and oligotrophic environments, all of them harbour phototrophic mats and other environments such as acidic hot springs or acid mine drainage harbour non-photosynthetic mats. This review analyses the complex structure, diversity, and interactions between the microorganisms that form the framework of different types of microbial mats located around the globe. Furthermore, the many tools that allow studying microbial mats in depth and their potential biotechnological applications are discussed.

  4. Bamboo–Polylactic Acid (PLA Composite Material for Structural Applications

    Directory of Open Access Journals (Sweden)

    Angel Pozo Morales

    2017-11-01

    Full Text Available Developing an eco-friendly industry based on green materials, sustainable technologies, and optimum processes with low environmental impact is a general societal goal, but this remains a considerable challenge to achieve. Despite the large number of research on green structural composites, limited investigation into the most appropriate manufacturing methodology to develop a structural material at industrial level has taken place. Laboratory panels have been manufactured with different natural fibers but the methodologies and values obtained could not be extrapolated at industrial level. Bamboo industry panels have increased in the secondary structural sector such as building application, flooring and sport device, because it is one of the cheapest raw materials. At industrial level, the panels are manufactured with only the inner and intermediate region of the bamboo culm. However, it has been found that the mechanical properties of the external shells of bamboo culm are much better than the average cross-sectional properties. Thin strips of bamboo (1.5 mm thick and 1500 mm long were machined and arranged with the desired lay-up and shape to obtain laminates with specific properties better than those of conventional E-Glass/Epoxy laminates in terms of both strength and stiffness. The strips of bamboo were bonded together by a natural thermoplastic polylactic acid (PLA matrix to meet biodegradability requirements. The innovative mechanical extraction process developed in this study can extract natural strip reinforcements with high performance, low cost, and high rate, with no negative environmental impact, as no chemical treatments are used. The process can be performed at the industrial level. Furthermore, in order to validate the structural applications of the composite, the mechanical properties were analyzed under ageing conditions. This material could satisfy the requirements for adequate mechanical properties and life cycle costs at

  5. Bamboo-Polylactic Acid (PLA) Composite Material for Structural Applications.

    Science.gov (United States)

    Pozo Morales, Angel; Güemes, Alfredo; Fernandez-Lopez, Antonio; Carcelen Valero, Veronica; De La Rosa Llano, Sonia

    2017-11-09

    Developing an eco-friendly industry based on green materials, sustainable technologies, and optimum processes with low environmental impact is a general societal goal, but this remains a considerable challenge to achieve. Despite the large number of research on green structural composites, limited investigation into the most appropriate manufacturing methodology to develop a structural material at industrial level has taken place. Laboratory panels have been manufactured with different natural fibers but the methodologies and values obtained could not be extrapolated at industrial level. Bamboo industry panels have increased in the secondary structural sector such as building application, flooring and sport device, because it is one of the cheapest raw materials. At industrial level, the panels are manufactured with only the inner and intermediate region of the bamboo culm. However, it has been found that the mechanical properties of the external shells of bamboo culm are much better than the average cross-sectional properties. Thin strips of bamboo (1.5 mm thick and 1500 mm long) were machined and arranged with the desired lay-up and shape to obtain laminates with specific properties better than those of conventional E-Glass/Epoxy laminates in terms of both strength and stiffness. The strips of bamboo were bonded together by a natural thermoplastic polylactic acid (PLA) matrix to meet biodegradability requirements. The innovative mechanical extraction process developed in this study can extract natural strip reinforcements with high performance, low cost, and high rate, with no negative environmental impact, as no chemical treatments are used. The process can be performed at the industrial level. Furthermore, in order to validate the structural applications of the composite, the mechanical properties were analyzed under ageing conditions. This material could satisfy the requirements for adequate mechanical properties and life cycle costs at industrial sectors such

  6. Process, structure, property and applications of metallic glasses

    Directory of Open Access Journals (Sweden)

    B. Geetha Priyadarshini

    2016-07-01

    Full Text Available Metallic glasses (MGs are gaining immense technological significance due to their unique structure-property relationship with renewed interest in diverse field of applications including biomedical implants, commercial products, machinery parts, and micro-electro-mechanical systems (MEMS. Various processing routes have been adopted to fabricate MGs with short-range ordering which is believed to be the genesis of unique structure. Understanding the structure of these unique materials is a long-standing unsolved mystery. Unlike crystalline counterpart, the outstanding properties of metallic glasses owing to the absence of grain boundaries is reported to exhibit high hardness, excellent strength, high elastic strain, and anti-corrosion properties. The combination of these remarkable properties would significantly contribute to improvement of performance and reliability of these materials when incorporated as bio-implants. The nucleation and growth of metallic glasses is driven by thermodynamics and kinetics in non-equilibrium conditions. This comprehensive review article discusses the various attributes of metallic glasses with an aim to understand the fundamentals of relationship process-structure-property existing in such unique class of material.

  7. The mathematical method of studying the reproduction structure of weeds and its application to Bromus sterilis

    NARCIS (Netherlands)

    Wang, J.; Hansen, P.K.; Christensen, S.; Qi, G.Z.

    2004-01-01

    This article discusses the structure of weed reproduction incorporating the application of a mathematical model. This mathematical methodology enables the construction, testing and application of distribution models for the analysis of the structure of weed reproduction and weed ecology. The

  8. Active Wireless System for Structural Health Monitoring Applications

    Directory of Open Access Journals (Sweden)

    Ricardo Perera

    2017-12-01

    Full Text Available The use of wireless sensors in Structural Health Monitoring (SHM has increased significantly in the last years. Piezoelectric-based lead zirconium titanate (PZT sensors have been on the rise in SHM due to their superior sensing abilities. They are applicable in different technologies such as electromechanical impedance (EMI-based SHM. This work develops a flexible wireless smart sensor (WSS framework based on the EMI method using active sensors for full-scale and autonomous SHM. In contrast to passive sensors, the self-sensing properties of the PZTs allow interrogating with or exciting a structure when desired. The system integrates the necessary software and hardware within a service-oriented architecture approach able to provide in a modular way the services suitable to satisfy the key requirements of a WSS. The framework developed in this work has been validated on different experimental applications. Initially, the reliability of the EMI method when carried out with the proposed wireless sensor system is evaluated by comparison with the wireless counterpart. Afterwards, the performance of the system is evaluated in terms of software stability and reliability of functioning.

  9. Polycaprolactone/starch composite: Fabrication, structure, properties, and applications.

    Science.gov (United States)

    Ali Akbari Ghavimi, Soheila; Ebrahimzadeh, Mohammad H; Solati-Hashjin, Mehran; Abu Osman, Noor Azuan

    2015-07-01

    Interests in the use of biodegradable polymers as biomaterials have grown. Among the different polymeric composites currently available, the blend of starch and polycaprolactone (PCL) has received the most attention since the 1980s. Novamont is the first company that manufactured a PCL/starch (SPCL) composite under the trademark Mater-Bi®. The properties of PCL (a synthetic, hydrophobic, flexible, expensive polymer with a low degradation rate) and starch (a natural, hydrophilic, stiff, abundant polymer with a high degradation rate) blends are interesting because of the composite components have completely different structures and characteristics. PCL can adjust humidity sensitivity of starch as a biomaterial; while starch can enhance the low biodegradation rate of PCL. Thus, by appropriate blending, SPCL can overcome important limitations of both PCL and starch components and promote controllable behavior in terms of mechanical properties and degradation which make it suitable for many biomedical applications. This article reviewed the different fabrication and modification methods of the SPCL composite; different properties such as structural, physical, and chemical as well as degradation behavior; and different applications as biomaterials. © 2014 Wiley Periodicals, Inc.

  10. Minor snake venom proteins: Structure, function and potential applications.

    Science.gov (United States)

    Boldrini-França, Johara; Cologna, Camila Takeno; Pucca, Manuela Berto; Bordon, Karla de Castro Figueiredo; Amorim, Fernanda Gobbi; Anjolette, Fernando Antonio Pino; Cordeiro, Francielle Almeida; Wiezel, Gisele Adriano; Cerni, Felipe Augusto; Pinheiro-Junior, Ernesto Lopes; Shibao, Priscila Yumi Tanaka; Ferreira, Isabela Gobbo; de Oliveira, Isadora Sousa; Cardoso, Iara Aimê; Arantes, Eliane Candiani

    2017-04-01

    Snake venoms present a great diversity of pharmacologically active compounds that may be applied as research and biotechnological tools, as well as in drug development and diagnostic tests for certain diseases. The most abundant toxins have been extensively studied in the last decades and some of them have already been used for different purposes. Nevertheless, most of the minor snake venom protein classes remain poorly explored, even presenting potential application in diverse areas. The main difficulty in studying these proteins lies on the impossibility of obtaining sufficient amounts of them for a comprehensive investigation. The advent of more sensitive techniques in the last few years allowed the discovery of new venom components and the in-depth study of some already known minor proteins. This review summarizes information regarding some structural and functional aspects of low abundant snake venom proteins classes, such as growth factors, hyaluronidases, cysteine-rich secretory proteins, nucleases and nucleotidases, cobra venom factors, vespryns, protease inhibitors, antimicrobial peptides, among others. Some potential applications of these molecules are discussed herein in order to encourage researchers to explore the full venom repertoire and to discover new molecules or applications for the already known venom components. Copyright © 2016. Published by Elsevier B.V.

  11. Advances in aluminium alloy products for structural applications in transportation

    International Nuclear Information System (INIS)

    Staley, J.T.; Lege, D.J.

    1993-01-01

    This paper describes the needs of the aviation and automotive markets for structural materials and presents examples of developments of aluminum alloy products to fill these needs. Designers of aircraft desire materials which will allow them to design lightweight, cost-effective structures which have the performance characteristics of durability and damage tolerance. Their needs are being met by new and emerging materials varying from Al-Li alloys for thick structure, high-strength plate and extrusions for wings, and new monolithic and aluminum-fiber laminates for fuselages. Increase in fuel economy because of lighter weight structure is the driving force for aluminum alloys in the automotive market, and cost is extremely important. Mechanical properties for automotive use also depend on the application, and corrosion resistance must be adequate. For ''hang-on'' components such as fenders and hoods, formability is typically the limiting mechanical property. Strength must be adequate to resist denting at a thickness which offers cost-effective weight savings over steel. Because formability often decreases with increasing yield strength, alloys which are highly formable in the T4 temper and which age harden during the paint bake operation were developed. Alloys such as 6009 and 6010 are now being challenged by 2008, 6111 and 6016. Body structure components must be made from materials which absorb energy and fail gracefully during a crash. Such components for an automotive space frame are being die cast from an Al-Si-Mg alloy. These ductile die castings are joined to thin 6XXX extrusions which must combine formability, strength, ductility and the ability to deform plastically on impact. Bumpers must combine strength and adequate formability; in the event that current alloys are inadequate for future needs, a new 7XXX alloy offers an improved combination of properties. (orig.)

  12. Application of symmetry operation measures in structural inorganic chemistry.

    Science.gov (United States)

    Echeverría, Jorge; Alvarez, Santiago

    2008-12-01

    This paper presents an application of the recently proposed symmetry operation measures to the determination of the effective symmetry point group of coordination polyhedra in inorganic solids. Several structure types based on octahedra are found to present distinct distortion patterns each, not strictly attached to the crystallographic site symmetry. These include the (NH4)2[CuCl4], CdI2 (brucite), FeS2 (pyrite), TiO2 (rutile), CaCl2, GdFeO3, PbTiO3,LiNbO3, BiI3, CrCl3, Al2O3, and NiWO4 structures. It is shown that a similar analysis can be applied to the Bailar and tetragonal Jahn-Teller distortions of molecular transition metal complexes, as well as to solids based on tetrahedra, such as the ZnCl2, FeS, BeCl2, SiS2, and KFeS2 structure types.

  13. Application of photoreflectance to advanced multilayer structures for photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Fuertes Marrón, D., E-mail: dfuertes@ies-def.upm.es [Instituto de Energía Solar – ETSIT, Technical University of Madrid, UPM, Madrid (Spain); Cánovas, E.; Artacho, I. [Instituto de Energía Solar – ETSIT, Technical University of Madrid, UPM, Madrid (Spain); Stanley, C.R.; Steer, M. [Department of Electronics and Electrical Engineering, University of Glasgow (United Kingdom); Kaizu, T.; Shoji, Y.; Ahsan, N.; Okada, Y. [Research Center for Advanced Science and Technology, University of Tokyo (Japan); Barrigón, E.; Rey-Stolle, I.; Algora, C.; Martí, A.; Luque, A. [Instituto de Energía Solar – ETSIT, Technical University of Madrid, UPM, Madrid (Spain)

    2013-05-15

    Highlights: ► Application of photoreflectance to advanced PV structures. ► Probing optoelectronics of nanostructures and multinary compounds. ► Determination of intensity of electric fields from FKOs. ► Distinguishing different oscillatory phenomena in PR. ► PR as a useful diagnostic tool in QD-, QW-SCs and MJSCs. -- Abstract: Photoreflectance (PR) is a convenient characterization tool able to reveal optoelectronic properties of semiconductor materials and structures. It is a simple non-destructive and contactless technique which can be used in air at room temperature. We will present experimental results of the characterization carried out by means of PR on different types of advanced photovoltaic (PV) structures, including quantum-dot-based prototypes of intermediate band solar cells, quantum-well structures, highly mismatched alloys, and III–V-based multi-junction devices, thereby demonstrating the suitability of PR as a powerful diagnostic tool. Examples will be given to illustrate the value of this spectroscopic technique for PV including (i) the analysis of the PR spectra in search of critical points associated to absorption onsets; (ii) distinguishing signatures related to quantum confinement from those originating from delocalized band states; (iii) determining the intensity of the electric field related to built-in potentials at interfaces according to the Franz–Keldysh (FK) theory; and (v) determining the nature of different oscillatory PR signals among those ascribed to FK-oscillations, interferometric and photorefractive effects. The aim is to attract the interest of researchers in the field of PV to modulation spectroscopies, as they can be helpful in the analysis of their devices.

  14. Application of photoreflectance to advanced multilayer structures for photovoltaics

    International Nuclear Information System (INIS)

    Fuertes Marrón, D.; Cánovas, E.; Artacho, I.; Stanley, C.R.; Steer, M.; Kaizu, T.; Shoji, Y.; Ahsan, N.; Okada, Y.; Barrigón, E.; Rey-Stolle, I.; Algora, C.; Martí, A.; Luque, A.

    2013-01-01

    Highlights: ► Application of photoreflectance to advanced PV structures. ► Probing optoelectronics of nanostructures and multinary compounds. ► Determination of intensity of electric fields from FKOs. ► Distinguishing different oscillatory phenomena in PR. ► PR as a useful diagnostic tool in QD-, QW-SCs and MJSCs. -- Abstract: Photoreflectance (PR) is a convenient characterization tool able to reveal optoelectronic properties of semiconductor materials and structures. It is a simple non-destructive and contactless technique which can be used in air at room temperature. We will present experimental results of the characterization carried out by means of PR on different types of advanced photovoltaic (PV) structures, including quantum-dot-based prototypes of intermediate band solar cells, quantum-well structures, highly mismatched alloys, and III–V-based multi-junction devices, thereby demonstrating the suitability of PR as a powerful diagnostic tool. Examples will be given to illustrate the value of this spectroscopic technique for PV including (i) the analysis of the PR spectra in search of critical points associated to absorption onsets; (ii) distinguishing signatures related to quantum confinement from those originating from delocalized band states; (iii) determining the intensity of the electric field related to built-in potentials at interfaces according to the Franz–Keldysh (FK) theory; and (v) determining the nature of different oscillatory PR signals among those ascribed to FK-oscillations, interferometric and photorefractive effects. The aim is to attract the interest of researchers in the field of PV to modulation spectroscopies, as they can be helpful in the analysis of their devices

  15. Alkaloids in the pharmaceutical industry: Structure, isolation and application

    Directory of Open Access Journals (Sweden)

    Nikolić Milan

    2003-01-01

    Full Text Available By the end of the 18th and the beginning of the 19th century a new era began in medicine, pharmaceutics and chemistry that was strongly connected with alkaloids and alkaloid drugs. Even before that it was known that certain drugs administered in limited doses were medicines, and toxic if taken in larger doses (opium, coke leaves, belladonna roots, monkshood tubers crocus or hemlock seeds. However, the identification, isolation and structural characterization of the active ingredients of the alkaloid drugs was only possible in the mid 20th century by the use of modern extraction equipment and instrumental methods (NMR, X-ray diffraction and others.In spite of continuing use over a long time, there is still great interest in investigating new drugs, potential raw materials for the pharmaceutical industry, as well as the more detailed investigation and definition of bio-active components and the indication of their activity range, and the partial synthesis of new alkaloid molecules based on natural alkaloids. The scope of these investigations, especially in the field of semi-synthesis is to make better use of the bio-active ingredients of alkaloid drugs, i.e. to improve the pharmacological effect (stronger and prolonged effect of the medicine, decreased toxicity and side effects, or to extend or change the applications. A combined classification of alkaloids was used, based on the chemical structure and origin, i.e. the source of their isolation to study alkaloid structure. For practical reasons, the following classification of alkaloids was used: ergot alkaloids, poppy alkaloids, tropanic alkaloids purine derivative alkaloids, carbon-cyclic alkaloids, and other alkaloids. The second part of this report presents a table of general procedures for alkaloid isolation from plant drugs (extraction by water non-miscible solvents, extraction by water-miscible solvents and extraction by diluted acid solutions. Also, methods for obtaining chelidonine and

  16. Structural Equation Modeling: Theory and Applications in Forest Management

    Directory of Open Access Journals (Sweden)

    Tzeng Yih Lam

    2012-01-01

    Full Text Available Forest ecosystem dynamics are driven by a complex array of simultaneous cause-and-effect relationships. Understanding this complex web requires specialized analytical techniques such as Structural Equation Modeling (SEM. The SEM framework and implementation steps are outlined in this study, and we then demonstrate the technique by application to overstory-understory relationships in mature Douglas-fir forests in the northwestern USA. A SEM model was formulated with (1 a path model representing the effects of successively higher layers of vegetation on late-seral herbs through processes such as light attenuation and (2 a measurement model accounting for measurement errors. The fitted SEM model suggested a direct negative effect of light attenuation on late-seral herbs cover but a direct positive effect of northern aspect. Moreover, many processes have indirect effects mediated through midstory vegetation. SEM is recommended as a forest management tool for designing silvicultural treatments and systems for attaining complex arrays of management objectives.

  17. Low Dimensional Semiconductor Structures Characterization, Modeling and Applications

    CERN Document Server

    Horing, Norman

    2013-01-01

    Starting with the first transistor in 1949, the world has experienced a technological revolution which has permeated most aspects of modern life, particularly over the last generation. Yet another such revolution looms up before us with the newly developed capability to control matter on the nanometer scale. A truly extraordinary research effort, by scientists, engineers, technologists of all disciplines, in nations large and small throughout the world, is directed and vigorously pressed to develop a full understanding of the properties of matter at the nanoscale and its possible applications, to bring to fruition the promise of nanostructures to introduce a new generation of electronic and optical devices. The physics of low dimensional semiconductor structures, including heterostructures, superlattices, quantum wells, wires and dots is reviewed and their modeling is discussed in detail. The truly exceptional material, Graphene, is reviewed; its functionalization and Van der Waals interactions are included h...

  18. Radiative sky cooling: fundamental physics, materials, structures, and applications

    Science.gov (United States)

    Sun, Xingshu; Sun, Yubo; Zhou, Zhiguang; Alam, Muhammad Ashraful; Bermel, Peter

    2017-07-01

    Radiative sky cooling reduces the temperature of a system by promoting heat exchange with the sky; its key advantage is that no input energy is required. We will review the origins of radiative sky cooling from ancient times to the modern day, and illustrate how the fundamental physics of radiative cooling calls for a combination of properties that may not occur in bulk materials. A detailed comparison with recent modeling and experiments on nanophotonic structures will then illustrate the advantages of this recently emerging approach. Potential applications of these radiative cooling materials to a variety of temperature-sensitive optoelectronic devices, such as photovoltaics, thermophotovoltaics, rectennas, and infrared detectors, will then be discussed. This review will conclude by forecasting the prospects for the field as a whole in both terrestrial and space-based systems.

  19. 77 FR 21404 - Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Airplanes

    Science.gov (United States)

    2012-04-10

    ... Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Airplanes AGENCY... airworthiness directive (AD) for all Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model 382... this AD, contact Lockheed Martin Corporation/Lockheed Martin Aeronautics Company, Airworthiness Office...

  20. 75 FR 39724 - Sixth Meeting-Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services

    Science.gov (United States)

    2010-07-12

    ...: Inmarsat Aeronautical Mobile Satellite (Route) Services AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of RTCA Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services... Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services. DATES: The meeting will be held...

  1. 75 FR 15770 - Fifth Meeting-Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services

    Science.gov (United States)

    2010-03-30

    ...: Inmarsat Aeronautical Mobile Satellite (Route) Services AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of RTCA Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services... Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services. DATES: The meeting will be held...

  2. 75 FR 63534 - Seventh Meeting-Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services

    Science.gov (United States)

    2010-10-15

    ... 222: Inmarsat Aeronautical Mobile Satellite (Route) Services AGENCY: Federal Aviation Administration... Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services. DATES: The meeting will be held... hereby given for a Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services. The...

  3. 78 FR 13383 - Public Availability of the National Aeronautics and Space Administration FY 2012 Service Contract...

    Science.gov (United States)

    2013-02-27

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION Public Availability of the National Aeronautics and Space Administration FY 2012 Service Contract Inventory (SCI) AGENCY: Office of Procurement, National Aeronautics and Space Administration. ACTION: Notice of Public Availability of the FY 2012 Service Contract...

  4. 77 FR 7183 - Public Availability of the National Aeronautics and Space Administration FY 2011 Service Contract...

    Science.gov (United States)

    2012-02-10

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION Public Availability of the National Aeronautics and Space Administration FY 2011 Service Contract Inventory AGENCY: National Aeronautics and Space Administration. ACTION: Notice of Public Availability of Analysis of the FY 2010 Service Contract Inventories and...

  5. 76 FR 6827 - Public Availability of the National Aeronautic and Space Administration FY 2010 Service Contract...

    Science.gov (United States)

    2011-02-08

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION Public Availability of the National Aeronautic and Space Administration FY 2010 Service Contract Inventory AGENCY: National Aeronautic and Space Administration. ACTION: Notice of public availability of FY 2010 Service Contract Inventories. [[Page 6828...

  6. APPLICABILITY OF SIMILARITY CONDITIONS TO ANALOGUE MODELLING OF TECTONIC STRUCTURES

    Directory of Open Access Journals (Sweden)

    Mikhail A. Goncharov

    2010-01-01

    Full Text Available The publication is aimed at comparing concepts of V.V. Belousov and M.V. Gzovsky, outstanding researchers who established fundamentals of tectonophysics in Russia, specifically similarity conditions in application to tectonophysical modeling. Quotations from their publications illustrate differences in their views. In this respect, we can reckon V.V. Belousov as a «realist» as he supported «the liberal point of view» [Methods of modelling…, 1988, p. 21–22], whereas M.V. Gzovsky can be regarded as an «idealist» as he believed that similarity conditions should be mandatorily applied to ensure correctness of physical modeling of tectonic deformations and structures [Gzovsky, 1975, pp. 88 and 94].Objectives of the present publication are (1 to be another reminder about desirability of compliance with similarity conditions in experimental tectonics; (2 to point out difficulties in ensuring such compliance; (3 to give examples which bring out the fact that similarity conditions are often met per se, i.e. automatically observed; (4 to show that modeling can be simplified in some cases without compromising quantitative estimations of parameters of structure formation.(1 Physical modelling of tectonic deformations and structures should be conducted, if possible, in compliance with conditions of geometric and physical similarity between experimental models and corresponding natural objects. In any case, a researcher should have a clear vision of conditions applicable to each particular experiment.(2 Application of similarity conditions is often challenging due to unavoidable difficulties caused by the following: a Imperfection of experimental equipment and technologies (Fig. 1 to 3; b uncertainties in estimating parameters of formation of natural structures, including main ones: structure size (Fig. 4, time of formation (Fig. 5, deformation properties of the medium wherein such structures are formed, including, first of all, viscosity (Fig. 6

  7. Nano-Structured Materials for Energy Storage Applications

    Science.gov (United States)

    Zhao, Dongxue

    Hydrogen is a non-polluting and efficient energy carrier. One barrier to utilizing hydrogen is a reliable storage method. NaAlH4 is the prototypical example of a complex metal hydride with high hydrogen storage capacities (˜ 5.5 wt.%) and acceptable reaction temperatures of around 100 °C when using catalyst. On decomposition of these complex hydrides, such as NaAlH4, one is left with monohydride NaH. The kinetics of diffusion in the monohydrides is important because reversibility hinges on mass transport and the formation of [AlH4]- anions that must structurally coordinate with the alkali metal cation on hydrogen absorption. The NaH/NaOH system of a variety of molar ratios was investigated using in situ X-ray diffraction and differential scanning calorimetry. Nano porous carbons (NPC) materials have mesoporous structure, large surface area (> 600 m2/g), and high pore volume (> 0.5 cc/g). Several NPC materials for both hydrogen storage and battery applications were prepared and discussed. Nano-sized TiO2 is a superior material for lithium-ion batteries due to its high stability, low volume change on lithiation (˜ 3%), and high energy density. High purity (˜ 100%) anatase TiO2 nano particles with controllable particle size from 9 to 38 nm and excellent electrochemical properties (> 220 mAh/g) were synthesized using an efficient and reliable method. The synthesis, characterization and electrochemical measurements of prepared anatase TiO2 nano particles for lithium-ion battery applications were discussed. The lithium diffusion behaviors in TiO2 and SnO 2 nano particles were analyzed and compared using an extension of the galvanostatic intermittent titration technique (GITT) that utilizes the open cell potential of the relaxation portion of the GITT measurement.

  8. 14 CFR 1251.502 - Application.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Application. 1251.502 Section 1251.502 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION NONDISCRIMINATION ON BASIS OF HANDICAP... Aeronautics and Space Administration § 1251.502 Application. This regulation (§§ 1251.501-1251.570) applies to...

  9. Application of Nano-SIMS on Organo-Mineral Structures

    International Nuclear Information System (INIS)

    Hoeschen, Carmen; Mueller, Carsten W.; Heister, Katja; Lugmeier, Johann; Koegel-Knabner, Ingrid

    2013-01-01

    The elemental interaction in soil material happens on extremely small scales due to soils submicron particle size. As all chemical elements and their isotopes can be present in soil samples, and isotope enrichment can be used for tracing, the secondary ion mass spectrometry is the technique of choice to visualize elemental and isotopic distribution. SIMS sputters surface atoms and registers them in accordance to their atomic mass. With the Cameca Nano-SIMS an instrument with very high lateral resolution of down to 50 nm and additionally very high mass resolving power is available. This allows for visualising the elemental and isotopic distribution inside a sample although absolute quantification can hardly be achieved. For quantitative analysis measurements have to be compared to known standard samples. Therefore perfect crystallographic preparation is required to avoid sputter enhancement on topographic features. Measurement data is available in binary format and can be processed by any image processing soft-ware providing adequate input filters. Applications on montmorillonite soil fragments and organo-mineral structures are presented revealing the lateral resolution of the Nano-SIMS technique and confirming their application to soil samples. The technique also seems to be promising for the investigation of material transport on small lateral scale in clay material. (authors)

  10. Rf structure of superconducting cyclotron for therapy application

    International Nuclear Information System (INIS)

    Takekoshi, Hidekuni; Matsuki, Seishi; Mashiko, Katuo; Shikazono, Naomoto.

    1981-01-01

    Advantages of fast neutrons in therapeutical application are now widely recognized. Fast neutrons are generated by bombarding a thick beryllium target with high energy protons and deuterons. The AVF cyclotrons which deliver 50 MeV protons and 25 MeV deuterons are commonly used and are commercially available now. At the treatment usually rotational irradiation is taken to prevent an injury to normal tissue from the high LET effect of fast neutrons. The construction cost of both cyclotrons and isocentric irradiation installation are relatively high, so that the spread of neutron therapy is obstructed. A superconducting cyclotron for neutron therapy application was proposed by a Chalk River group. This low cost design allows the installation to be a dedicated facility located in a hospital, and small size allows installations of the complete cyclotron in a rotatable gantry. The design studies of the superconducting cyclotron based on this idea are going on at Kyoto University. The full scale model experiments for a rf structure of the cyclotron were carried out. (author)

  11. Development of nonlinear acoustic propagation analysis tool toward realization of loud noise environment prediction in aeronautics

    Energy Technology Data Exchange (ETDEWEB)

    Kanamori, Masashi, E-mail: kanamori.masashi@jaxa.jp; Takahashi, Takashi, E-mail: takahashi.takashi@jaxa.jp; Aoyama, Takashi, E-mail: aoyama.takashi@jaxa.jp [Japan Aerospace Exploration Agency, 7-44-1, Jindaijihigashi-machi, Chofu, Tokyo (Japan)

    2015-10-28

    Shown in this paper is an introduction of a prediction tool for the propagation of loud noise with the application to the aeronautics in mind. The tool, named SPnoise, is based on HOWARD approach, which can express almost exact multidimensionality of the diffraction effect at the cost of back scattering. This paper argues, in particular, the prediction of the effect of atmospheric turbulence on sonic boom as one of the important issues in aeronautics. Thanks to the simple and efficient modeling of the atmospheric turbulence, SPnoise successfully re-creates the feature of the effect, which often emerges in the region just behind the front and rear shock waves in the sonic boom signature.

  12. An integrated runtime and compile-time approach for parallelizing structured and block structured applications

    Science.gov (United States)

    Agrawal, Gagan; Sussman, Alan; Saltz, Joel

    1993-01-01

    Scientific and engineering applications often involve structured meshes. These meshes may be nested (for multigrid codes) and/or irregularly coupled (called multiblock or irregularly coupled regular mesh problems). A combined runtime and compile-time approach for parallelizing these applications on distributed memory parallel machines in an efficient and machine-independent fashion was described. A runtime library which can be used to port these applications on distributed memory machines was designed and implemented. The library is currently implemented on several different systems. To further ease the task of application programmers, methods were developed for integrating this runtime library with compilers for HPK-like parallel programming languages. How this runtime library was integrated with the Fortran 90D compiler being developed at Syracuse University is discussed. Experimental results to demonstrate the efficacy of our approach are presented. A multiblock Navier-Stokes solver template and a multigrid code were experimented with. Our experimental results show that our primitives have low runtime communication overheads. Further, the compiler parallelized codes perform within 20 percent of the code parallelized by manually inserting calls to the runtime library.

  13. Bismuth Silver Oxysulfide for Photoconversion Applications: Structural and Optoelectronic Properties

    KAUST Repository

    Baqais, Amal Ali Abdulallh

    2017-09-18

    Single-phase bismuth silver oxysulfide, BiAgOS, was prepared by a hydrothermal method. Its structural, morphological and optoelectronic properties were investigated and compared with bismuth copper oxysulfide (BiCuOS). Rietveld refinement of the powder X-ray diffraction (XRD) measurements revealed that the BiAgOS and BiCuOS crystals have the same structure as ZrSiCuAs: the tetragonal space group P4/nmm. X-ray photoelectron spectroscopy (XPS) analyses confirmed that the BiAgOS has a high purity, in contrast with BiCuOS, which tends to have Cu vacancies. The Ag has a monovalent oxidation state, whereas Cu is present in the oxidation states of +1 and +2 in the BiCuOS system. Combined with experimental measurements, density functional theory calculations employing the range-separated hybrid HSE06 exchange-correlation functional with spin-orbit coupling quantitatively elucidated photophysical properties such as ab-sorption coefficients, effective masses and dielectric constants. BiCuOS and BiAgOS were found to have indirect bandgaps of 1.1 and 1.5 eV, respectively. Both possess high dielectric constants and low electron and hole effective masses. Therefore, these materials are expected to have high exciton dissociation capabilities and excellent carrier diffusion properties. This study reveals that BiAgOS is a promising candidate for photoconversion applications.

  14. X-Aerogels for Structural Components and High Temperature Applications

    Science.gov (United States)

    2005-01-01

    Future NASA missions and space explorations rely on the use of materials that are strong ultra lightweight and able to withstand extreme temperatures. Aerogels are low density (0.01-0.5 g/cu cm) high porosity materials that contain a glass like structure formed through standard sol-gel chemistry. As a result of these structural properties, aerogels are excellent thermal insulators and are able to withstand temperatures in excess of l,000 C. The open structure of aerogels, however, renders these materials extremely fragile (fracturing at stress forces less than 0.5 N/sq cm). The goal of NASA Glenn Research Center is to increase the strength of these materials by templating polymers and metals onto the surface of an aerogel network facilitating the use of this material for practical applications such as structural components of space vehicles used in exploration. The work this past year focused on two areas; (1) the research and development of new templated aerogels materials and (2) process development for future manufacturing of structural components. Research and development occurred on the production and characterization of new templating materials onto the standard silica aerogel. Materials examined included polymers such as polyimides, fluorinated isocyanates and epoxies, and, metals such as silver, gold and platinum. The final properties indicated that the density of the material formed using an isocyanate is around 0.50 g/cc with a strength greater than that of steel and has low thermal conductivity. The process used to construct these materials is extremely time consuming and labor intensive. One aspect of the project involved investigating the feasibility of shortening the process time by preparing the aerogels in the templating solvent. Traditionally the polymerization used THF as the solvent and after several washes to remove any residual monomers and water, the solvent around the aerogels was changed to acetonitrile for the templating step. This process

  15. III - V semiconductor structures for biosensor and molecular electronics applications

    Energy Technology Data Exchange (ETDEWEB)

    Luber, S.M.

    2007-01-15

    The present work reports on the employment of III-V semiconductor structures to biosensor and molecular electronics applications. In the first part a sensor based on a surface-near two dimensional electron gas for a use in biological environment is studied. Such a two dimensional electron gas inherently forms in a molecular beam epitaxy (MBE) grown, doped aluminum gallium arsenide - gallium arsenide (AlGaAs-GaAs) heterostructure. Due to the intrinsic instability of GaAs in aqueous solutions the device is passivated by deposition of a monolayer of 4'-substituted mercaptobiphenyl molecules. The influence of these molecules which bind to the GaAs via a sulfur group is investigated by Kelvin probe measurements in air. They reveal a dependence of GaAs electron affinity on the intrinsic molecular dipole moment of the mercaptobiphenyls. Furthermore, transient surface photovoltage measurements are presented which demonstrate an additional influence of mercaptobiphenyl chemisorption on surface carrier recombination rates. As a next step, the influence of pH-value and salt concentration upon the sensor device is discussed based on the results obtained from sensor conductance measurements in physiological solutions. A dependence of the device surface potential on both parameters due to surface charging is deduced. Model calculations applying Poisson-Boltzmann theory reveal as possible surface charging mechanisms either the adsorption of OH- ions on the surface, or the dissociation of OH groups in surface oxides. A comparison between simulation settings and physical device properties indicate the OH- adsorption as the most probable mechanism. In the second part of the present study the suitability of MBE grown III-V semiconductor structures for molecular electronics applications is examined. In doing so, a method to fabricate nanometer separated, coplanar, metallic electrodes based on the cleavage of a supporting AlGaAs-GaAs heterostructure is presented. This is followed

  16. Application of Finite Layer Method in Pavement Structural Analysis

    Directory of Open Access Journals (Sweden)

    Pengfei Liu

    2017-06-01

    Full Text Available The finite element (FE method has been widely used in predicting the structural responses of asphalt pavements. However, the three-dimensional (3D modeling in general-purpose FE software systems such as ABAQUS requires extensive computations and is relatively time-consuming. To address this issue, a specific computational code EasyFEM was developed based on the finite layer method (FLM for analyzing structural responses of asphalt pavements under a static load. Basically, it is a 3D FE code that requires only a one-dimensional (1D mesh by incorporating analytical methods and using Fourier series in the other two dimensions, which can significantly reduce the computational time and required resources due to the easy implementation of parallel computing technology. Moreover, a newly-developed Element Energy Projection (EEP method for super-convergent calculations was implemented in EasyFEM to improve the accuracy of solutions for strains and stresses over the whole pavement model. The accuracy of the program is verified by comparing it with results from BISAR and ABAQUS for a typical asphalt pavement structure. The results show that the predicted responses from ABAQUS and EasyFEM are in good agreement with each other. The EasyFEM with the EEP post-processing technique converges faster compared with the results derived from ordinary EasyFEM applications, which proves that the EEP technique can improve the accuracy of strains and stresses from EasyFEM. In summary, the EasyFEM has a potential to provide a flexible and robust platform for the numerical simulation of asphalt pavements and can easily be post-processed with the EEP technique to enhance its advantages.

  17. Synthesis and applications of novel silver nanoparticle structures

    Science.gov (United States)

    Dukes, Kyle

    The field of nanotechnology is rapidly expanding across disciplines as each new development is realized. New exciting technologies are being driven by advances in the application of nanotechnology; including biochemical, optical, and semiconductors research. This thesis will focus on the use of silver nanoparticles as optical labels on cells, methods of forming different small structures of silver nanoparticles, as well as the use of silver nanoparticles in the development of a photovoltaic cell. Silver nanoparticles have been modified with self-assembled monolayers of hydroxyl-terminated long chain thiols and encapsulated with a silica shell. The resulting core-shell nanoparticles were used as optical labels for cell analysis using flow cytometry and microscopy. The excitation of plasmon resonances in nanoparticles results in strong depolarized scattering of visible light permitting detection at the single nanoparticle level. The nanoparticles were modified with neutravidin via epoxide-azide coupling chemistry and biotinylated antibodies targeting cell surface receptors were bound to the nanoparticle surface. The nanoparticle labels exhibited long-term stability under physiological conditions without aggregation or silver ion leaching. Labeled cells exhibited two orders of magnitude enhancement of the scattering intensity compared to unlabeled cells. Dimers of silver nanoparticles have been fabricated by first immobilizing a monolayer of single silver nanoparticles onto poly(4-vinylpyridine) covered glass slides. The monolayer was then exposed to adenine, which has two amines which will bind to silver. The nanoparticle monolayer, now modified with adenine, is exposed to a second suspension of nanoparticles which will bind with the amine modified monolayer. Finally, a thin silica shell is formed about the structure via solgel chemistry to prevent dissolution or aggregation upon sonication/striping. Circular arrays of silver nanoparticels are developed using a

  18. National Aeronautics and Space Administration (NASA) Education 1993-2009

    Science.gov (United States)

    Ivie, Christine M.

    2009-01-01

    The National Aeronautics and Space Administration was established in 1958 and began operating a formal education program in 1993. The purpose of this study was to analyze the education program from 1993-2009 by examining strategic plan documents produced by the NASA education office and interviewing NASA education officials who served during that…

  19. Aeronautics Study Takes Off! Glider Design for Beginners

    Science.gov (United States)

    Lazaros, Edward J.; Carlson, Katie

    2008-01-01

    Study of aeronautics is an interesting and motivating subject for students and educators alike. The activity described in this article--appropriate for upper elementary or middle school students--provides an excellent introduction to airplane design and the science of aerodynamics. It also gives students good experience applying knowledge from a…

  20. The Vernier System at the Faculty of Aeronautics

    Science.gov (United States)

    Budajová, Kristína; Komová, Eva; Berežný, Štefan; Glaser-Opitz, Henrich

    2017-01-01

    This article describes an educational challenge which was prepared for students at the faculty of Aeronautics, Technical University of Košice. Our goal is to improve the methods of the practical training by introducing modern automation and information technologies to the experiments and to the processing of acquired data. We have updated our…

  1. 77 FR 38091 - NASA Advisory Council; Aeronautics Committee; Meeting.

    Science.gov (United States)

    2012-06-26

    ... Research update NASA Aeronautics Research Mission Directorate Education and Public Outreach activities The.... citizenship must provide to NASA the following information: Full name; gender; date/ place of birth; social.../place of birth; citizenship; social security number; green card information (resident alien number...

  2. Aerobasics–An Introduction to Aeronautics-Airplane Propulsion

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 7. Aerobasics – An Introduction to Aeronautics - Airplane Propulsion. S P Govinda Raju. Series Article Volume 14 Issue 7 July 2009 pp 650-666. Fulltext. Click here to view fulltext PDF. Permanent link:

  3. Applications of the Cambridge Structural Database in organic chemistry and crystal chemistry.

    Science.gov (United States)

    Allen, Frank H; Motherwell, W D Samuel

    2002-06-01

    The Cambridge Structural Database (CSD) and its associated software systems have formed the basis for more than 800 research applications in structural chemistry, crystallography and the life sciences. Relevant references, dating from the mid-1970s, and brief synopses of these papers are collected in a database, DBUse, which is freely available via the CCDC website. This database has been used to review research applications of the CSD in organic chemistry, including supramolecular applications, and in organic crystal chemistry. The review concentrates on applications that have been published since 1990 and covers a wide range of topics, including structure correlation, conformational analysis, hydrogen bonding and other intermolecular interactions, studies of crystal packing, extended structural motifs, crystal engineering and polymorphism, and crystal structure prediction. Applications of CSD information in studies of crystal structure precision, the determination of crystal structures from powder diffraction data, together with applications in chemical informatics, are also discussed.

  4. Cryo-focused-ion-beam applications in structural biology.

    Science.gov (United States)

    Rigort, Alexander; Plitzko, Jürgen M

    2015-09-01

    The ability to precisely control the preparation of biological samples for investigations by electron cryo-microscopy is becoming increasingly important for ultrastructural imaging in biology. Precision machining instruments such as the focused ion beam microscope (FIB) were originally developed for applications in materials science. However, today we witness a growing use of these tools in the life sciences mainly due to their versatility, since they can be used both as manipulation and as imaging devices, when complemented with a scanning electron microscope (SEM). The advent of cryo-preparation equipment and accessories made it possible to pursue work on frozen-hydrated biological specimens with these two beam (FIB/SEM) instruments. In structural biology, the cryo-FIB can be used to site-specifically thin vitrified specimens for transmission electron microscopy (TEM) and tomography. Having control over the specimen thickness is a decisive factor for TEM imaging, as the thickness of the object under scrutiny determines the attainable resolution. Besides its use for TEM preparation, the FIB/SEM microscope can be additionally used to obtain three-dimensional volumetric data from biological specimens. The unique combination of an imaging and precision manipulation tool allows sequentially removing material with the ion beam and imaging the milled block faces by scanning with the electron beam, an approach known as FIB/SEM tomography. This review covers both fields of cryo-FIB applications: specimen preparation for TEM cryo-tomography and volume imaging by cryo-FIB/SEM tomography. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Avaliações térmica e reológica da matriz termoplástica PEKK utilizada em compósitos aeronáuticos Thermal and rheological evaluation of PEKK thermoplastic matrix for aeronautical application

    Directory of Open Access Journals (Sweden)

    Rogério L. Mazur

    2008-09-01

    resistance combined with its low density make PEKK an attractive option for a variety of applications in aerospace and aeronautical field. The aim of the present work is to analyze the influence of the thermal and rheological parameters of PEKK using the techniques Fourier Transform InfraRed (FT-IR, differential scanning calorimetry (DSC, thermogravimetry (TG and rheology, in the definition of processing thermal cycle to be utilized with the hot compression molding of thermoplastic composites. The results obtained from the thermal and rheological analyses showed that PEKK has an attractive balance of properties, such as a high transition temperature (Tg = 153-156 °C and of being able to be processed at a moderate temperature, between the melting (310-325 °C and degradation (352-366 °C temperatures, mainly when compared with other polymers, including PEEK (polyether ether ketone, PEI (Polyetherimide and PPS (polyphenylene sulfide. From these results, it was possible to establish appropriate thermal and rheological parameters to be used in hot compression molding of advanced polymeric laminates.

  6. Modeling of ultrasonic propagation in a diffusing metallurgical structure, application to NDC; Modelisation de la propagation ultrasonore dans une structure metallurgique diffusante, application au CND

    Energy Technology Data Exchange (ETDEWEB)

    Dorval, V.

    2009-12-15

    Scattering phenomena can interfere with the ultrasonic non destructive testing of certain materials. It occurs for example in the testing of certain types of steels used in nuclear power plants, or of titanium alloys used in aeronautics. The scattering of ultrasonic waves by the microstructure of those materials induces structural noise and attenuation, which can have a significant impact on detection performances. This thesis deals with the modeling and computing of those phenomena. A model is used to determine the scattering properties of a metal, based on its microstructure. This model was adapted to different categories of metals. A method to compute structural noise based on this model was developed. It relies on the pencil method to perform semi-analytical computations of tridimensional ultrasonic fields. An original approach is used to limit the time necessary to compute noise signal. The computation is based on outputs of the model. This approach is based on the single scattering approximation. Noise signals computed using this method were compared to experimental results. Those comparisons confirm the relevance of the method. They also illustrate the importance of interference phenomena in structural noise. A second computation method that takes into account multiple scattering has been studied. It is based on a Monte-Carlo method applied to the radiative transfer theory. (author)

  7. Application of Structure from Mortion in Japanese Archaeology

    Science.gov (United States)

    Kaneda, A.; Nawabi, Y. A.; Yamaguchi, H.

    2015-08-01

    In Japan, archaeological excavations carry out over fifty thousand times per year. Nowadays, archaeological data is accumulated day by day. To record these documentation about archaeological data, it is desirable to the documentation of their shape in 3-dimensional form. Structure from Motion (SfM) is the one of the cost effective method to record the 3D documentation. This paper introduces application of SfM technology to examine the validity of an archaeological documentation in Japanese archaeology in recent year. Whenever, a complicated form finding has to be recorded at an archaeological excavation. It often requires a long time to create by a traditional manual drawing. For example, a well made of reuse roof tiles, garden stones and stone chamber. By using SfM, the time spent working at the archaeological site was greatly reduced. And many platforms to take an image at the variety of archaeological site's condition, like a small UAV (Unmanned Aerial Vehicle) are tested using for wider area recording. These methods are used in disaster stricken areas in East Japan.

  8. A New Defected Ground Structure for Different Microstrip Circuit Applications

    Directory of Open Access Journals (Sweden)

    S. Das

    2007-04-01

    Full Text Available In this paper, a microstrip transmission line combined with a new U-headed dumb-bell defected ground structure (DGS is investigated. The proposed DGS of two U-shape slots connected by a thin transverse slot is placed in the ground plane of a microstrip line. A finite cutoff frequency and attenuation pole is observed and thus, the equivalent circuit of the DGS unit can be represented by a parallel LC resonant circuit in series with the transmission line. A two-cell DGS microstrip line yields a better lowpass filtering characteristics. The simulation is carried out by the MoM based IE3D software and in the experimental measurements a vector network analyzer is used. The effects of the transverse slot width and the distance between arms of the U-slot on the filter response curve are studied. This DGS is utilized for different microstrip circuit applications. The DGS is placed in the ground of a capacitive loaded microstrip line and a very low cutoff frequency is obtained. The DGS is adopted under the coupled lines of a parallel line coupler and an improvement in coupling coefficient is noticed. The proposed DGS is also incorporated in the ground plane under the feed lines and the coupled lines of a bandpass filter to improve separately the stopband and passband performances.

  9. Research and development entitled smart structures for fossil energy applications

    Science.gov (United States)

    Claus, R. O.

    1990-12-01

    Two different fiber optic sensors were considered for use in ceramic cross flow filters. The intensity-based sensor was tested with a great degree of success. Even with a computerized data acquisition system, the intensity based sensor was unable to achieve the resolution of the Fabry-Perot sensor. Another drawback of the intensity sensor is the hysteresis behavior observed over cyclic variation of temperature. It was determined that Fabry-Perot fiber optic sensors can be used to measure thermal strains in ceramic cross flow filters with accuracies of 0.1 micron/m. The single ended approach of the reflective Fabry-Perot sensors is well suited for high thermal strain measurements; the results obtained show that the output of the fiber sensor tracks the temperature changes exactly as expected and shows no noticeable time lag between the measurand and the output signal. Sapphire fibers were manufactured with silica claddings and their spectral attenuation was measured. An intensity based sensor using sapphire fibers was fabricated and its performance calibrated. The success of the Fabry-Perot sensor has proved that such fiber optic sensors are well suited for smart structures in fossil energy applications.

  10. Research and development entitled smart structures for fossil energy applications

    Energy Technology Data Exchange (ETDEWEB)

    Claus, R.O.

    1990-12-01

    Two different fiber optic sensors were considered for use in ceramic cross flow filters. The intensity-based sensor was tested with a great degree of success. Even with a computerized data acquisition system, the intensity-based sensor was unable to achieve the resolution of the Fabry-Perot sensor. Another drawback of the intensity sensor is the hysteresis behavior observed over cyclic variation of temperature. We have determined that extrinsic Fabry-Perot fiber optic sensors can be used to measure thermal strains in ceramic cross-flow filters with accuracies of 0.1 {mu}m/m. The single ended approach of the reflective Fabry-Perot sensors is well suited for high thermal strain measurements; the results obtained show that the output of the fiber sensor tracks the temperature changes exactly as expected and shows no noticeable time lag between the measurand and the output signal. Sapphire fibers were manufactured with silica claddings and their spectral attenuation was measured. An intensity based sensor using sapphire fibers was fabricated and its performance calibrated. The success of the Fabry-Perot sensor has proved that such fiber optic sensors are ideally suited for smart structures'' in fossil energy applications. 11 refs., 43 figs.

  11. 77 FR 59020 - NASA Advisory Council; Aeronautics Committee; Unmanned Aircraft Systems Subcommittee; Meeting

    Science.gov (United States)

    2012-09-25

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice 12-073] NASA Advisory Council; Aeronautics Committee; Unmanned Aircraft Systems Subcommittee; Meeting AGENCY: National Aeronautics and Space... Law 92-463, as amended, the National Aeronautics and Space Administration announces a meeting of the...

  12. Aeronautics: An Educator's Guide with Activities in Science, Mathematics, and Technology Education.

    Science.gov (United States)

    National Aeronautics and Space Administration, Washington, DC.

    This educator's guide, developed for students in grades 2-4, discusses the field of aeronautics. It begins with education standards and skill matrices for the classroom activities, a description of the National Aeronautics and Space Administration (NASA) aeronautics mission, and a brief history of aeronautics. Activities are written for the…

  13. 78 FR 38076 - NASA Advisory Council; Aeronautics Committee; Unmanned Aircraft Systems Subcommittee; Meeting

    Science.gov (United States)

    2013-06-25

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice 13-069] NASA Advisory Council; Aeronautics Committee; Unmanned Aircraft Systems Subcommittee; Meeting AGENCY: National Aeronautics and Space... Law 92-463, as amended, the National Aeronautics and Space Administration announces a meeting of the...

  14. 76 FR 75565 - NASA Advisory Council; Aeronautics Committee; Unmanned Aircraft Systems (UAS) Subcommittee Meeting

    Science.gov (United States)

    2011-12-02

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice (11-116)] NASA Advisory Council; Aeronautics Committee; Unmanned Aircraft Systems (UAS) Subcommittee Meeting AGENCY: National Aeronautics and Space... Law 92-463, as amended, the National Aeronautics and Space Administration announces a meeting of the...

  15. 78 FR 7816 - NASA Advisory Council; Aeronautics Committee; Unmanned Aircraft Systems Subcommittee Meeting

    Science.gov (United States)

    2013-02-04

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice: (13-008)] NASA Advisory Council; Aeronautics Committee; Unmanned Aircraft Systems Subcommittee Meeting AGENCY: National Aeronautics and Space... Law 92-463, as amended, the National Aeronautics and Space Administration announces a meeting of the...

  16. 78 FR 25100 - NASA Advisory Council; Aeronautics Committee; Unmanned Aircraft Systems Subcommittee; Meeting

    Science.gov (United States)

    2013-04-29

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice: (13-051)] NASA Advisory Council; Aeronautics Committee; Unmanned Aircraft Systems Subcommittee; Meeting AGENCY: National Aeronautics and Space... Law 92-463, as amended, the National Aeronautics and Space Administration announces a meeting of the...

  17. A tabu search evalutionary algorithm for multiobjective optimization: Application to a bi-criterion aircraft structural reliability problem

    Science.gov (United States)

    Long, Kim Chenming

    application of the proposed algorithm, TSEA, with several state-of-the-art multiobjective optimization algorithms reveals that TSEA outperforms these algorithms by providing retrofit solutions with greater reliability for the same costs (i.e., closer to the Pareto-optimal front) after the algorithms are executed for the same number of generations. This research also demonstrates that TSEA competes with and, in some situations, outperforms state-of-the-art multiobjective optimization algorithms such as NSGA II and SPEA 2 when applied to classic bicriteria test problems in the technical literature and other complex, sizable real-world applications. The successful implementation of TSEA contributes to the safety of aeronautical structures by providing a systematic way to guide aircraft structural retrofitting efforts, as well as a potentially useful algorithm for a wide range of multiobjective optimization problems in engineering and other fields.

  18. National Aeronautics and Space Administration Fiscal Year 2001 Accountability Report

    Science.gov (United States)

    2002-01-01

    The National Aeronautics and Space Administration (NASA) is an independent Agency established to plan and manage the future of the Nation's civil aeronautics and space program. This Accountability Report covers Federal Fiscal Year (FY) 2001 (October 1, 2000, through September 30, 2001), with discussion of some subsequent events. The Report contains an overview addressing the Agency's critical programs and financial performance and includes highlights of performance organized by goals and objectives of the Enterprises and Crosscutting Processes. The Report also summarizes NASA's stewardship over budget and financial resources, including audited financial statements and footnotes. The financial statements reflect an overall position of offices and activities, including assets and liabilities, as well as results of operations, pursuant to requirements of Federal law (31 U.S.C. 3515(b)). The auditor's opinions on NASA's financial statements, reports on internal controls, and compliance with laws and regulations are included in this report.

  19. A Comparative Study of Multi-material Data Structures for Computational Physics Applications

    Energy Technology Data Exchange (ETDEWEB)

    Garimella, Rao Veerabhadra [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Robey, Robert W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-31

    The data structures used to represent the multi-material state of a computational physics application can have a drastic impact on the performance of the application. We look at efficient data structures for sparse applications where there may be many materials, but only one or few in most computational cells. We develop simple performance models for use in selecting possible data structures and programming patterns. We verify the analytic models of performance through a small test program of the representative cases.

  20. Transmissive/Reflective Structural Color Filters: Theory and Applications

    OpenAIRE

    Yan Yu; Long Wen; Shichao Song; Qin Chen

    2014-01-01

    Structural color filters, which obtain color selection by varying structures, have attracted extensive research interest in recent years due to the advantages of compactness, stability, multifunctions, and so on. In general, the mechanisms of structural colors are based on the interaction between light and structures, including light diffraction, cavity resonance, and surface plasmon resonance. This paper reviews recent progress of various structural color techniques and the integration appli...

  1. National Aeronautics and Space Administration Workshop on Monitoring and Diagnosis

    OpenAIRE

    Doyle, Richard J.

    1992-01-01

    The First National Aeronautics and Space Administration (NASA) Workshop on Monitoring and Diagnosis was held in Pasadena, California, from 15 to 17 January 1992. The workshop brought together individuals from NASA centers, academia, and aerospace who have a common interest in AI-based approaches to monitoring and diagnosis technology. The workshop was intended to promote familiarity, discussion, and collaboration among the research, development, and user communities.

  2. Tribology needs for future space and aeronautical systems

    Science.gov (United States)

    Fusaro, Robert L.

    1991-01-01

    Future aeronautical and space missions will push tribology technology beyond its current capability. The objective is to discuss the current state of the art of tribology as it is applied to advanced aircraft and spacecraft. Areas of discussion include materials lubrication mechanisms, factors affecting lubrication, current and future tribological problem areas, potential new lubrication techniques, and perceived technology requirements that need to be met in order to solve these tribology problems.

  3. Semiconducting boron carbide thin films: Structure, processing, and diode applications

    Science.gov (United States)

    Bao, Ruqiang

    The high energy density and long lifetime of betavoltaic devices make them very useful to provide the power for applications ranging from implantable cardiac pacemakers to deep space satellites and remote sensors. However, when made with conventional semiconductors, betavoltaic devices tend to suffer rapid degradation as a result of radiation damage. It has been suggested that the degradation problem could potentially be alleviated by replacing conventional semiconductors with a radiation hard semiconducting material like icosahedral boron carbide. The goal of my dissertation was to better understand the fundamental properties and structure of boron carbide thin films and to explore the processes to fabricate boron carbide based devices for voltaic applications. A pulsed laser deposition system and a radio frequency (RF) magnetron sputtering deposition system were designed and built to achieve the goals. After comparing the experimental results obtained using these two techniques, it was concluded that RF magnetron sputtering deposition technique is a good method to make B4C boron carbide thin films to fabricate repeatable and reproducible voltaic devices. The B4C thin films deposited by RF magnetron sputtering require in situ dry pre-cleaning to make ohmic contacts for B4C thin films to fabricate the devices. By adding another RF sputtering to pre-clean the substrate and thin films, a process to fabricate B4C / n-Si heterojunctions has been established. In addition, a low energy electron accelerator (LEEA) was built to mimic beta particles emitted from Pm147 and used to characterize the betavoltaic performance of betavoltaic devices as a function of beta energy and beta flux as well as do accelerated lifetime testing for betavoltaic devices. The energy range of LEEA is 20 - 250 keV with the current from several nA to 50 muA. High efficiency Si solar cells were used to demonstrate the powerful capabilities of LEEA, i.e., the characterization of betavoltaic

  4. Behaviour of AR glass fibre for building structural applications

    Directory of Open Access Journals (Sweden)

    Miravete, A.

    2005-12-01

    Full Text Available The AR glass reinforcement fibres were designed to resist the alkalis from the concrete. This is the main reason for its utilisation as a short-fibre-reinforcement of mortar and concrete for the last decades. Originally, the AR glass fibre sizing was not compatible with synthetic resins, so that this type of reinforcement was applied exclusively to mortar and concrete matrices. Recently, due to the developments of sizing, which are compatible with synthetic resins, the AR- glass fibres may be used as reinforcement of organic matrix composite materials, broadening the range of structural applications. The mechanical properties of AR glass fibre and organic matrix composite materials will be studied in this paper. First, the behaviour of this material under stress corrosion will be analysed. Their mass loss will be compared to E, C, and boron free glass fibres. Second, an experimental study dealing with 3P test bending and short beam ofAR glass fibre/polyester will de described with the goal of obtaining their Young modulus and tensile and interlaminar shear strengths. Finally, these experimental results will be compared to E glass fibre/polyester and several conclusions about their structural applications will be drawn.

    El vidrio AR y su presentación en forma de fibras de refuerzo, fue diseñado para ser inerte a los álcalis de los cementos. Por este motivo se viene utilizando desde hace varias décadas como refuerzo de morteros y hormigones en forma de fibra corta. El ensimaje que estas fibras de vidrio de refuerzo A R presentaba en su origen no era compatible con resinas de tipo sintéticas, por lo que el refuerzo era exclusivo para cementos y hormigones fuera cual fuera la aplicación, formato o proceso productivo. Recientemente, gracias al desarrollo específico de ensimajes especiales acordes a las fibras de vidrio AR ha aparecido la misma tipología de vidrio AR como refuerzo en forma de fibra continua compatible con resinas sint

  5. Superhydrophobic hierarchically structured surfaces in biology: evolution, structural principles and biomimetic applications.

    Science.gov (United States)

    Barthlott, W; Mail, M; Neinhuis, C

    2016-08-06

    A comprehensive survey of the construction principles and occurrences of superhydrophobic surfaces in plants, animals and other organisms is provided and is based on our own scanning electron microscopic examinations of almost 20 000 different species and the existing literature. Properties such as self-cleaning (lotus effect), fluid drag reduction (Salvinia effect) and the introduction of new functions (air layers as sensory systems) are described and biomimetic applications are discussed: self-cleaning is established, drag reduction becomes increasingly important, and novel air-retaining grid technology is introduced. Surprisingly, no evidence for lasting superhydrophobicity in non-biological surfaces exists (except technical materials). Phylogenetic trees indicate that superhydrophobicity evolved as a consequence of the conquest of land about 450 million years ago and may be a key innovation in the evolution of terrestrial life. The approximate 10 million extant species exhibit a stunning diversity of materials and structures, many of which are formed by self-assembly, and are solely based on a limited number of molecules. A short historical survey shows that bionics (today often called biomimetics) dates back more than 100 years. Statistical data illustrate that the interest in biomimetic surfaces is much younger still. Superhydrophobicity caught the attention of scientists only after the extreme superhydrophobicity of lotus leaves was published in 1997. Regrettably, parabionic products play an increasing role in marketing.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. © 2016 The Author(s).

  6. Superhydrophobic hierarchically structured surfaces in biology: evolution, structural principles and biomimetic applications

    Science.gov (United States)

    Mail, M.; Neinhuis, C.

    2016-01-01

    A comprehensive survey of the construction principles and occurrences of superhydrophobic surfaces in plants, animals and other organisms is provided and is based on our own scanning electron microscopic examinations of almost 20 000 different species and the existing literature. Properties such as self-cleaning (lotus effect), fluid drag reduction (Salvinia effect) and the introduction of new functions (air layers as sensory systems) are described and biomimetic applications are discussed: self-cleaning is established, drag reduction becomes increasingly important, and novel air-retaining grid technology is introduced. Surprisingly, no evidence for lasting superhydrophobicity in non-biological surfaces exists (except technical materials). Phylogenetic trees indicate that superhydrophobicity evolved as a consequence of the conquest of land about 450 million years ago and may be a key innovation in the evolution of terrestrial life. The approximate 10 million extant species exhibit a stunning diversity of materials and structures, many of which are formed by self-assembly, and are solely based on a limited number of molecules. A short historical survey shows that bionics (today often called biomimetics) dates back more than 100 years. Statistical data illustrate that the interest in biomimetic surfaces is much younger still. Superhydrophobicity caught the attention of scientists only after the extreme superhydrophobicity of lotus leaves was published in 1997. Regrettably, parabionic products play an increasing role in marketing. This article is part of the themed issue ‘Bioinspired hierarchically structured surfaces for green science’. PMID:27354736

  7. Applications of Piezoelectric Materials in Structural Health Monitoring and Repair: Selected Research Examples.

    Science.gov (United States)

    Duan, Wen Hui; Wang, Quan; Quek, Ser Tong

    2010-12-06

    The paper reviews the recent applications of piezoelectric materials in structural health monitoring and repair conducted by the authors. First, commonly used piezoelectric materials in structural health monitoring and structure repair are introduced. The analysis of plain piezoelectric sensors and actuators and interdigital transducer and their applications in beam, plate and pipe structures for damage detection are reviewed in detail. Second, an overview is presented on the recent advances in the applications of piezoelectric materials in structural repair. In addition, the basic principle and the current development of the technique are examined.

  8. Applications of Piezoelectric Materials in Structural Health Monitoring and Repair: Selected Research Examples

    Directory of Open Access Journals (Sweden)

    Ser Tong Quek

    2010-12-01

    Full Text Available The paper reviews the recent applications of piezoelectric materials in structural health monitoring and repair conducted by the authors. First, commonly used piezoelectric materials in structural health monitoring and structure repair are introduced. The analysis of plain piezoelectric sensors and actuators and interdigital transducer and their applications in beam, plate and pipe structures for damage detection are reviewed in detail. Second, an overview is presented on the recent advances in the applications of piezoelectric materials in structural repair. In addition, the basic principle and the current development of the technique are examined.

  9. The National Aeronautics and Space Administration interdisciplinary studies in space technology at the University of Kansas

    Science.gov (United States)

    Barr, B. G.

    1974-01-01

    A broad range of research projects contained in a cooperative space technology program at the University of Kansas are reported as they relate to the following three areas of interdisciplinary interest: (1) remote sensing of earth resources; (2) stability and control of light and general aviation aircraft; and (3) the vibrational response characteristics of aeronautical and space vehicles. Details of specific research efforts are given under their appropriate departments, among which are aerospace engineering, chemical and petroleum engineering, environmental health, water resources, the remote sensing laboratory, and geoscience applications studies.

  10. A Tool for Measuring NASA's Aeronautics Research Progress Toward Planned Strategic Community Outcomes

    Science.gov (United States)

    Tahmasebi, Farhad; Pearce, Robert

    2016-01-01

    Description of a tool for portfolio analysis of NASA's Aeronautics research progress toward planned community strategic Outcomes is presented. For efficiency and speed, the tool takes advantage of a function developed in Excels Visual Basic for Applications. The strategic planning process for determining the community Outcomes is also briefly discussed. Stakeholder buy-in, partnership performance, progress of supporting Technical Challenges, and enablement forecast are used as the criteria for evaluating progress toward Outcomes. A few illustrative examples of using the tool are also presented.

  11. Choice of FDMA/SCPC access technique for aeronautical satellite voice system

    Science.gov (United States)

    Smith, G. K.

    1989-03-01

    A worldwide aeronautical mobile satellite system is about to become operational. The system architecture and access methods have been debated extensively, resulting in the selection of Time Division Multiplexing/Time Division Multiple Access (TDM/TDMA) access for packet data, and Single Channel Per Carrier (SCPC) for voice. These have become standards for airline use, and also satisfy the known requirements of ICAO for safety related communications. Voice communications are expected to absorb a high proportion of satellite bandwidth and power in the future. Here, it is explained why INMARSAT selected Frequency Division Multiple Access/SCPC satellite access for this application.

  12. Modal analysis application for dynamic characterization of simple structures

    International Nuclear Information System (INIS)

    Pastorini, A.J.; Belinco, C.G.

    1987-01-01

    The knowledge of the dynamic characteristics of a structure helps to foresee the vibrating behaviour under operating conditions. The modal analysis techniques offer a method to perform the dynamic characterization of a studied structure from the vibration modes of such structure. A hammer provided with a loaded cell to excite a wide frequency band and accelerometer and, on the basis of a measurement of the transfer function at different points, various simple structures were given with a dynamic structures analysis (of the type of Fourier's rapidly transformation) and the results were compared with those obtained by other methods. Different fields where these techniques are applied, are also enumerated. (Author)

  13. NUMERICAL CALCULATIONS IN GEOMECHANICS APPLICABLE TO LINEAR STRUCTURES

    Directory of Open Access Journals (Sweden)

    Vlasov Aleksandr Nikolaevich

    2012-10-01

    Full Text Available The article covers the problem of applicability of finite-element and engineering methods to the development of a model of interaction between pipeline structures and the environment in the complex conditions with a view to the simulation and projection of exogenous geological processes, trustworthy assessment of their impacts on the pipeline, and the testing of varied calculation methodologies. Pipelining in the areas that have a severe continental climate and permafrost soils is accompanied by cryogenic and exogenous processes and developments. It may also involve the development of karst and/or thermokarst. The adverse effect of the natural environment is intensified by the anthropogenic impact produced onto the natural state of the area, causing destruction of forests and other vegetation, changing the ratio of soils in the course of the site planning, changing the conditions that impact the surface and underground waters, and causing the thawing of the bedding in the course of the energy carrier pumping, etc. The aforementioned consequences are not covered by effective regulatory documents. The latter constitute general and incomplete recommendations in this respect. The appropriate mathematical description of physical processes in complex heterogeneous environments is a separate task to be addressed. The failure to consider the above consequences has repeatedly caused both minor damages (denudation of the pipeline, insulation stripping and substantial accidents; the rectification of their consequences was utterly expensive. Pipelining produces a thermal impact on the environment; it may alter the mechanical properties of soils and de-frost the clay. The stress of the pipeline is one of the principal factors that determines its strength and safety. The pipeline stress exposure caused by loads and impacts (self-weight, internal pressure, etc. may be calculated in advance, and the accuracy of these calculations is sufficient for practical

  14. Testing simulation and structural models with applications to energy demand

    Science.gov (United States)

    Wolff, Hendrik

    2007-12-01

    This dissertation deals with energy demand and consists of two parts. Part one proposes a unified econometric framework for modeling energy demand and examples illustrate the benefits of the technique by estimating the elasticity of substitution between energy and capital. Part two assesses the energy conservation policy of Daylight Saving Time and empirically tests the performance of electricity simulation. In particular, the chapter "Imposing Monotonicity and Curvature on Flexible Functional Forms" proposes an estimator for inference using structural models derived from economic theory. This is motivated by the fact that in many areas of economic analysis theory restricts the shape as well as other characteristics of functions used to represent economic constructs. Specific contributions are (a) to increase the computational speed and tractability of imposing regularity conditions, (b) to provide regularity preserving point estimates, (c) to avoid biases existent in previous applications, and (d) to illustrate the benefits of our approach via numerical simulation results. The chapter "Can We Close the Gap between the Empirical Model and Economic Theory" discusses the more fundamental question of whether the imposition of a particular theory to a dataset is justified. I propose a hypothesis test to examine whether the estimated empirical model is consistent with the assumed economic theory. Although the proposed methodology could be applied to a wide set of economic models, this is particularly relevant for estimating policy parameters that affect energy markets. This is demonstrated by estimating the Slutsky matrix and the elasticity of substitution between energy and capital, which are crucial parameters used in computable general equilibrium models analyzing energy demand and the impacts of environmental regulations. Using the Berndt and Wood dataset, I find that capital and energy are complements and that the data are significantly consistent with duality

  15. Cage structure application in photoelectric experiment and teaching

    Science.gov (United States)

    Li, Xiufang; Zhao, Peng; Liu, Shugang

    2017-08-01

    A new type of photoelectric system structure, cage system, is introduced. This kind of coaxial modularized structure not only can be quickly assembled, but also can easily realize different purposes by substituting elements in the system. In addition, it's light and portable, which enable teachers to carry it to wherever suitable for teaching. In conclusion, this structure can improve teaching effect and stimulate student's interest in photoelectric courses.

  16. Metamaterial based embedded acoustic filters for structural applications

    Directory of Open Access Journals (Sweden)

    Hongfei Zhu

    2013-09-01

    Full Text Available We investigate the use of acoustic metamaterials to design structural materials with frequency selective characteristics. By exploiting the properties of acoustic metamaterials, we tailor the propagation characteristics of the host structure to effectively filter the constitutive harmonics of an incoming broadband excitation. The design approach exploits the characteristics of acoustic waveguides coupled by cavity modes. By properly designing the cavity we can tune the corresponding resonant mode and, therefore, coupling the waveguide at a prescribed frequency. This structural design can open new directions to develop broadband passive vibrations and noise control systems fully integrated in structural components.

  17. Elementary continuum mechanics for everyone with applications to structural mechanics

    CERN Document Server

    Byskov, Esben

    2013-01-01

    The book opens with a derivation of kinematically nonlinear 3-D continuum mechanics for solids. Then the principle of virtual work is utilized to derive the simpler, kinematically linear 3-D theory and to provide the foundation for developing consistent theories of kinematic nonlinearity and linearity for specialized continua, such as beams and plates, and finite element methods for these structures. A formulation in terms of the versatile Budiansky-Hutchinson notation is used as basis for the theories for these structures and structural elements, as well as for an in-depth treatment of structural instability.

  18. National Aeronautics and Space Administration Science and Engineering Apprentice Program

    Science.gov (United States)

    1997-01-01

    The National Aeronautics and Space Administration's Science and Engineering Apprentice Program for high school students is one of NASA's many efforts toward a goal of scientific literacy. It embraces science, mathematics, and technology as keys to purposeful and sustained progress and security for our nation and its people. It serves as a model for helping reform education by striving to address mechanisms to influence the knowledge, skills, and attitudes of our students. It focuses on what to do today to meet the challenges of tomorrow.

  19. Reliability program requirements for aeronautical and space system contractors

    Science.gov (United States)

    1987-01-01

    General reliability program requirements for NASA contracts involving the design, development, fabrication, test, and/or use of aeronautical and space systems including critical ground support equipment are prescribed. The reliability program requirements require (1) thorough planning and effective management of the reliability effort; (2) definition of the major reliability tasks and their place as an integral part of the design and development process; (3) planning and evaluating the reliability of the system and its elements (including effects of software interfaces) through a program of analysis, review, and test; and (4) timely status indication by formal documentation and other reporting to facilitate control of the reliability program.

  20. FY11 Facility Assessment Study for Aeronautics Test Program

    Science.gov (United States)

    Loboda, John A.; Sydnor, George H.

    2013-01-01

    This paper presents the approach and results for the Aeronautics Test Program (ATP) FY11 Facility Assessment Project. ATP commissioned assessments in FY07 and FY11 to aid in the understanding of the current condition and reliability of its facilities and their ability to meet current and future (five year horizon) test requirements. The principle output of the assessment was a database of facility unique, prioritized investments projects with budgetary cost estimates. This database was also used to identify trends for the condition of facility systems.

  1. A Flexible System for Simulating Aeronautical Telecommunication Network

    Science.gov (United States)

    Maly, Kurt; Overstreet, C. M.; Andey, R.

    1998-01-01

    At Old Dominion University, we have built Aeronautical Telecommunication Network (ATN) Simulator with NASA being the fund provider. It provides a means to evaluate the impact of modified router scheduling algorithms on the network efficiency, to perform capacity studies on various network topologies and to monitor and study various aspects of ATN through graphical user interface (GUI). In this paper we describe briefly about the proposed ATN model and our abstraction of this model. Later we describe our simulator architecture highlighting some of the design specifications, scheduling algorithms and user interface. At the end, we have provided the results of performance studies on this simulator.

  2. The Western Aeronautical Test Range. Chapter 10 Tools

    Science.gov (United States)

    Knudtson, Kevin; Park, Alice; Downing, Robert; Sheldon, Jack; Harvey, Robert; Norcross, April

    2011-01-01

    The Western Aeronautical Test Range (WATR) staff at the NASA Dryden Flight Research Center is developing a translation software called Chapter 10 Tools in response to challenges posed by post-flight processing data files originating from various on-board digital recorders that follow the Range Commanders Council Inter-Range Instrumentation Group (IRIG) 106 Chapter 10 Digital Recording Standard but use differing interpretations of the Standard. The software will read the date files regardless of the vendor implementation of the source recorder, displaying data, identifying and correcting errors, and producing a data file that can be successfully processed post-flight

  3. Abstracted Workow Framework with a Structure from Motion Application

    Science.gov (United States)

    Rossi, Adam J.

    In scientific and engineering disciplines, from academia to industry, there is an increasing need for the development of custom software to perform experiments, construct systems, and develop products. The natural mindset initially is to shortcut and bypass all overhead and process rigor in order to obtain an immediate result for the problem at hand, with the misconception that the software will simply be thrown away at the end. In a majority of the cases, it turns out the software persists for many years, and likely ends up in production systems for which it was not initially intended. In the current study, a framework that can be used in both industry and academic applications mitigates underlying problems associated with developing scientific and engineering software. This results in software that is much more maintainable, documented, and usable by others, specifically allowing new users to extend capabilities of components already implemented in the framework. There is a multi-disciplinary need in the fields of imaging science, computer science, and software engineering for a unified implementation model, which motivates the development of an abstracted software framework. Structure from motion (SfM) has been identified as one use case where the abstracted workflow framework can improve research efficiencies and eliminate implementation redundancies in scientific fields. The SfM process begins by obtaining 2D images of a scene from different perspectives. Features from the images are extracted and correspondences are established. This provides a sufficient amount of information to initialize the problem for fully automated processing. Transformations are established between views, and 3D points are established via triangulation algorithms. The parameters for the camera models for all views / images are solved through bundle adjustment, establishing a highly consistent point cloud. The initial sparse point cloud and camera matrices are used to generate a dense

  4. Wireless Structural Sensing for Health Monitoring and Control Applications

    Science.gov (United States)

    Lynch, J. P.

    2003-12-01

    The economic and societal impact of civil structures under-performing during large earthquakes can be significant. While in recent years the structural engineering community has made great strides in advancing knowledge of structural behavior under extreme loads, a need still exists for the rapid assessment of structural performance during seismic events. Numerous options are commercially available to facility owners who wish to install a structural monitoring system within their structures. However, these structural monitoring systems are defined by their use of coaxial cables for the transfer of response measurements from sensors to centralized data servers. The installation and maintenance of cables within a civil structure often drive system costs high thereby preventing widespread industry adoption. In response to these limitations, the integration of information technologies such as wireless communications and microcontrollers have been explored for the creation of alternative structural monitoring systems defined by low installation costs and decentralized computational frameworks. In particular, a novel wireless structural monitoring system assembled from a dense network of inexpensive wireless sensing units has been designed and fabricated. The wireless sensing unit architecture consists of three functional components: a data acquisition interface for the collection of data from attached sensors, a computational core for data interrogation, and a wireless communication channel for the transfer of data to the sensor network. The use of wireless modems drastically reduces the efforts and costs of system installations rendering the technology attractive for widespread adoption in a broad class of civil structures. A second innovation of the system is the inclusion of computational power within each wireless sensing unit allowing for local execution of embedded engineering analyses. In particular, analyses for the detection of damage in structures (structural

  5. A Generic Mesh Data Structure with Parallel Applications

    Science.gov (United States)

    Cochran, William Kenneth, Jr.

    2009-01-01

    High performance, massively-parallel multi-physics simulations are built on efficient mesh data structures. Most data structures are designed from the bottom up, focusing on the implementation of linear algebra routines. In this thesis, we explore a top-down approach to design, evaluating the various needs of many aspects of simulation, not just…

  6. Focused Ion Beam Nano-structuring for Applications in Photonics

    NARCIS (Netherlands)

    Ay, F.; de Ridder, R.M.; Pollnau, Markus

    2010-01-01

    To date, nano- and micro-structuring has commonly been implemented by a combination of specifically optimized processes of electron-beam lithography and reactive ion etching, thus limiting the range of materials that can be structured to only a few. In this talk we will introduce focused ion beam

  7. Multimedia Teleservices Modelled with the OSI Application Layer Structure

    NARCIS (Netherlands)

    van Rijssen, Erwin; Widya, I.A.; Michiels, E.F.; Hutchison, D.; Christiansen, H.; Coulson, G.; Danthine, A.A.S.

    This paper looks into the communications capabilities that are required by distributed multimedia applications to achieve relation preserving information exchange. These capabilities are derived by analyzing the notion of information exchange and are embodied in communications functionalities. To

  8. Review of Heterojunctin Bipolar Transistor Structure, Applications, and Reliability

    Science.gov (United States)

    Lee, C.; Kayali, S.

    1993-01-01

    Heterojunction Bipolar Transistors (HBTs) are increasingly employed in high frequency, high linerity, and high efficiency applications. As the utilization of these devices becomes more widespread, their operation will be viewed with more scrutiny.

  9. Multifunctional Structural Composite Batteries for U.S. Army Applications

    National Research Council Canada - National Science Library

    Snyder, J. F; Carter, R. H; Xu, K; Wong, E. I; Nguyen, P. A; Hgo, E. H; Wetzel, E. D

    2007-01-01

    ... supplementary power for light load applications. To enable this concept, we have designed load-bearing properties directly into the battery electrodes and electrolyte such that each component is itself multifunctional...

  10. Multimedia Teleservices Modelled with the OSI Application Layer Structure

    NARCIS (Netherlands)

    van Rijssen, Erwin; Widya, I.A.; Michiels, E.F.; Hutchison, D.; Christiansen, H.; Coulson, G.; Danthine, A.A.S.

    1995-01-01

    This paper looks into the communications capabilities that are required by distributed multimedia applications to achieve relation preserving information exchange. These capabilities are derived by analyzing the notion of information exchange and are embodied in communications functionalities. To

  11. Composite materials application on FORMOSAT-5 remote sensing instrument structure

    Directory of Open Access Journals (Sweden)

    Jen-Chueh Kuo

    2017-01-01

    Full Text Available Composite material has been widely applied in space vehicle structures due to its light weight and designed stiffness modulus. Some special mechanical properties that cannot be changed in general metal materials, such as low CTE (coefficient of thermal expansion and directional material stiffness can be artificially adjusted in composite materials to meet the user’s requirements. Space-qualified Carbon Fiber Reinforced Plastic (CFRP composite materials are applied In the FORMOSAT-5 Remote Sensing (RSI structure because of its light weight and low CTE characteristics. The RSI structural elements include the primary mirror supporting plate, secondary mirror supporting ring, and supporting frame. These elements are designed, manufactured, and verified using composite materials to meet specifications. The structure manufacturing process, detailed material properties, and CFRP structural element validation methods are introduced in this paper.

  12. Application of Bipolar Fuzzy Sets in Graph Structures

    Directory of Open Access Journals (Sweden)

    Muhammad Akram

    2016-01-01

    Full Text Available A graph structure is a useful tool in solving the combinatorial problems in different areas of computer science and computational intelligence systems. In this paper, we apply the concept of bipolar fuzzy sets to graph structures. We introduce certain notions, including bipolar fuzzy graph structure (BFGS, strong bipolar fuzzy graph structure, bipolar fuzzy Ni-cycle, bipolar fuzzy Ni-tree, bipolar fuzzy Ni-cut vertex, and bipolar fuzzy Ni-bridge, and illustrate these notions by several examples. We study ϕ-complement, self-complement, strong self-complement, and totally strong self-complement in bipolar fuzzy graph structures, and we investigate some of their interesting properties.

  13. Slow and fast light in semiconductor structures: physics and applications

    DEFF Research Database (Denmark)

    Mørk, Jesper; Nielsen, Torben Roland; Xue, Weiqi

    We discuss the physics and applications of slow light in semiconductor waveguides. In particular we introduce methods for enhancing the degree of light speed control considering both electromagnetically induced transparency as well as coherent population oscillations.......We discuss the physics and applications of slow light in semiconductor waveguides. In particular we introduce methods for enhancing the degree of light speed control considering both electromagnetically induced transparency as well as coherent population oscillations....

  14. Recent NASA progress in composites. [application to spacecraft and aircraft structures

    Science.gov (United States)

    Heldenfels, R. R.

    1975-01-01

    The application of composites in aerospace vehicle structures is reviewed. Research and technology program results and specific applications to space vehicles, aircraft engines, and aircraft and helicopter structures are discussed in detail. Particular emphasis is given to flight service evaluation programs that are or will be accumulating substantial experience with secondary and primary structural components on military and commercial aircraft to increase confidence in their use.

  15. Global energy issues affecting aeronautics: a reasoned conjecture

    Science.gov (United States)

    Allen, John E.

    1999-07-01

    This paper is a reasoned conjecture of the future up to 2050 AD including estimates of energy supply and consumption, transport system developments and corresponding pollution effects. Results of the logistic substitution methods (Volterra-Lotka) are used in forecasting trends in innovation, transport and energy. Later work on normative forecasts is also included. The future of aeronautics cannot be isolated from events in other transport modes which together create the major problem of crude oil replacement during the next century. Natural gas will be the dominant energy source for the next 80 years and a major question is how best to use it for aviation. The work on which this paper is based was started in 1992 to answer the following questions: Is the future oil shortfall sufficient to restrict aviation traffic and growth in the next 50 years? If so, what is its substitute? Can a substitute be obtained cheaply enough to free aviation from future kerosine shortages? Is it paramount to change to liquid hydrogen fuel to avoid future fuel shortage in aeronautics, incidentally conferring possible environmental advantages? There was no adequate evidence available to answer these questions, hence a method was devised to bring together several sets of partial data that contributed to the solution. The essence is to use the mean annual growth rate of traffic or energy over a future period as a pseudo-independent variable. This allows the inclusion of alternative high and low estimates of all the important quantities involved.

  16. Geocoded data structures and their applications to Earth science investigations

    Science.gov (United States)

    Goldberg, M.

    1984-01-01

    A geocoded data structure is a means for digitally representing a geographically referenced map or image. The characteristics of representative cellular, linked, and hybrid geocoded data structures are reviewed. The data processing requirements of Earth science projects at the Goddard Space Flight Center and the basic tools of geographic data processing are described. Specific ways that new geocoded data structures can be used to adapt these tools to scientists' needs are presented. These include: expanding analysis and modeling capabilities; simplifying the merging of data sets from diverse sources; and saving computer storage space.

  17. Application of nano-structured conducting polymers to humidity sensing

    Science.gov (United States)

    Park, Pilyeon

    Nanostructures, such as nanowires, nanocolumns, and nanotubes, have attracted a lot of attention because of their huge potential impact on a variety of applications. For sensor applications, nanostructures provide high surface area to volume ratios. The high surface area to volume ratio allows more reaction areas between target species and detection materials and also improves the detection sensitivity and response time. The main goal of this research was to exploit the advantages and develop innovative methods to accomplish the synthesis of nanowires and nano-coulmn conducting polymers used in humidity detection. To accomplish this, two fabrication methods are used. The first one utilizes the geometric confinement effect of a temporary nanochannel template to orient, precisely position, and assemble Polyaniline (PANI) nanowires as they are synthesized. The other approach is to simply spin-coat a polymer onto a substrate, and then oxygen plasma etch to generate a nano-columned Polyethylenedioxythiophene (PEDOT) thin film. 200 nm silicon oxide coated wafers with embedded platinum electrodes are used as a substrate for both fabrication methods. The biggest advantage of this first method is that it is simple, requires a single-step, i.e., synthesizing and positioning procedures are carried out simultaneously. The second method is potentially manufacturable and economic yet environmentally safe. These two methods do not produce extra nano-building materials to discard or create a health hazard. Both PANI nanowires and nano-columned PEDOT films have been tested for humidity detection using a system designed and built for this research to monitor response (current changes) to moisture, To explain the surface to volume ratio effect, 200 nm PANI nanowires and 10 microm PANI wires were directly compared for detecting moisture, and it was shown that the PANI nanowire had a better sensitivity. It was found difficult to monitor the behaviors of the PEDOT reaction to varying

  18. Deployable Composite Structures, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA is seeking innovative structure technologies that will advance expandable modules for orbital and surface based habitats. These secondary structures must...

  19. Applications of Multilevel Structural Equation Modeling to Cross-Cultural Research

    Science.gov (United States)

    Cheung, Mike W.-L.; Au, Kevin

    2005-01-01

    Multilevel structural equation modeling (MSEM) has been proposed as an extension to structural equation modeling for analyzing data with nested structure. We have begun to see a few applications in cross-cultural research in which MSEM fits well as the statistical model. However, given that cross-cultural studies can only afford collecting data…

  20. Analysis and Comparison of Magnetic Structures in a Tapped Boost Converter for LED Applications

    DEFF Research Database (Denmark)

    Mira Albert, Maria del Carmen; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    This paper presents an an alysis and comparison of magnetics structures in a tapped boost converter for LED applications. The magnetic structure is a coupled inductor which is analyzed in a conventional wire-wound core as well as in a planar structure for different interleaving winding arrangements...

  1. Deformation compatibility control for engineering structures methods and applications

    CERN Document Server

    Zhu, Hanhua; Chen, Mengchong; Deng, Jianliang

    2017-01-01

    This book presents essential methods of deformation compatibility control, and explicitly addresses the implied conditions on the methods’ deformation compatibility. Consequently, these conditions can be considered in engineering structure design, while the conditions on stable equilibrium can be taken into account in the design method. Thus, the designed deformation and the actual deformation of the respective structure are approximately identical, guaranteeing both the flexibility of the construction material in force transmission and the equilibrium of force in the structure. Though equilibrium theory in engineering structures has been extensively studied, there has been comparatively little research on compatibility. In the limited researches available, the topics are primarily the theories and assumptions on the deformation compatibility, while few systematic works focus on the mechanical theoretical principles and methods of deformation compatibility control. As such, the flexibility of the constructi...

  2. Autonomous Agents with Application to the Evaluation of Organizational Structures

    National Research Council Canada - National Science Library

    Curry, Michael L

    1999-01-01

    Experimental investigation of adaptive command and control (C2) organizations is limited in scope by the availability of qualified subjects and the complexity of experimental design and analysis for large organizational structures...

  3. Different Structures of PVA Nanofibrous Membrane for Sound Absorption Application

    Directory of Open Access Journals (Sweden)

    Jana Mohrova

    2012-01-01

    Full Text Available The thin nanofibrous layer has different properties in the field of sound absorption in comparison with porous fibrous material which works on a principle of friction of air particles in contact with walls of pores. In case of the thin nanofibrous layer, which represents a sound absorber here, the energy of sonic waves is absorbed by the principle of membrane resonance. The structure of the membrane can play an important role in the process of converting the sonic energy to a different energy type. The vibration system acts differently depending on the presence of smooth fibers in the structure, amount of partly merged fibers, or structure of polymer foil as extreme. Polyvinyl alcohol (PVA was used as a polymer because of its good water solubility. It is possible to influence the structure of nanofibrous layer during the production process thanks to this property of polyvinyl alcohol.

  4. APPLICATION FOR DESIGN OF STRUCTURAL ELEMENT USING VISUAL BASIC CODING

    OpenAIRE

    T. Thenmozhi; K. Nithya; M. Arun Kumar; M. Ravichandran

    2017-01-01

    The increasing reliance of engineers on computer software in the performance of their tasks requires engineers, the future professional engineers, must be knowledgeable of sound engineering concepts, updated on the latest computer technology used in the industry and aware of the limitations and capabilities of the computer in solving engineering problems. Computer Methods in Civil Engineering to developed structural design program for design of structural element using Visual Basic. By creati...

  5. Lifetime of Nano-Structured Black Silicon for Photovoltaic Applications

    DEFF Research Database (Denmark)

    Plakhotnyuk, Maksym; Davidsen, Rasmus Schmidt; Schmidt, Michael Stenbæk

    2016-01-01

    properties. We applied reactive ion etching technology at -20ºC to create nano-structures on silicon samples and obtained an average reflectance below 0.5%. For passivation purposes, we used 37 nm ALD Al2O3 films. Lifetime measurements resulted in 1220 µs and to 4170 µs for p- and ntype CZ silicon wafers......, respectively. This is promising for use of black silicon RIE nano-structuring in a solar cell process flow...

  6. Multifunctional Composite Structure

    Data.gov (United States)

    National Aeronautics and Space Administration — This project is developing a Composite Sandwich Habitable Pressurized Structure for deep space travel. Permeability, radiation, & micrometeoroids and orbital...

  7. 78 FR 10248 - Public Notice for Waiver of Aeronautical Land-Use Assurance

    Science.gov (United States)

    2013-02-13

    ... proposal to change a portion of airport land from aeronautical use to non-aeronautical use and to authorize the sale of the airport property. The Will County Department of Highways has offered fair market value...

  8. 3D plasmonic nanostar structures for recyclable SERS applications

    DEFF Research Database (Denmark)

    Chirumamilla, Manohar; Gopalakrishnan, Anisha; Toma, Andrea

    2015-01-01

    Nanofabrication of metallic nanostructures/nanoparticles enables the detection of analyte molecules at ultra-low concentrations with the aid of plasmon induced hot-spots. The high fabrication cost and large fabrication time of nanostructures limit their usage in practical applications. Here we pr...

  9. Application of EBG Structures at Sub-Array Level

    NARCIS (Netherlands)

    Bolt, R.J.; Bekers, D.J.; Llombart, N.; Neto, A.; Gerini, G.

    2006-01-01

    Low efficiency and pattern degradation are specific problems encountered in phased array designs based on integrated technology, as for example used in lowprofile radar applications. These problems are largely due to the excitation of surface waves (SW). It was demonstrated in earlier work that

  10. Structure, properties, and MEMS and microelectronic applications of ...

    Indian Academy of Sciences (India)

    Abstract. Vanadium oxides have for many decades attracted much attention for their rich and unique physical properties which pose intriguing questions as to their fundamental origins as well as offering numerous potential applications for microelectronics, sensors, and microelectromechanical systems (MEMS). This.

  11. Application of LCR Waves to Inspect Aircraft Structures

    Science.gov (United States)

    2013-01-01

    Mechanical Engineering (COBEM 2011). Proceedings of COBEM, 2011. Natal, RN, Brasil Analysis of the behavior of Lcr Waves propagating in Steel bars using...Taguchi Method. 21 th International Congress of Mechanical Engineering (COBEM 2011). Proceedings of COBEM, 2011. Natal, RN, Brasil . Application

  12. I-Structure software cache for distributed applications

    Directory of Open Access Journals (Sweden)

    Alfredo Cristóbal Salas

    2004-01-01

    Full Text Available En este artículo, describimos el caché de software I-Structure para entornos de memoria distribuida (D-ISSC, lo cual toma ventaja de la localidad de los datos mientras mantiene la capacidad de tolerancia a la latencia de sistemas de memoria I-Structure. Las facilidades de programación de los programas MPI, le ocultan los problemas de sincronización al programador. Nuestra evaluación experimental usando un conjunto de pruebas de rendimiento indica que clusters de PC con I-Structure y su mecanismo de cache D-ISSC son más robustos. El sistema puede acelerar aplicaciones de comunicación intensiva regulares e irregulares.

  13. Applications of modeling of structural equations in nursing: integrative review

    Directory of Open Access Journals (Sweden)

    Juliane Umann

    2017-12-01

    Full Text Available We analyzed the scientific production using modeling of structural equations in nursing. We conducted an integrative review in June of 2016 in the databases PUBMED, MEDLINE, and LILACS. We identified 127 articles, and we selected 20 from those. We conducted the analyses – quality and level of evidence – using validated tools and a synoptic table. The articles attended to 80% of STROBE items (95%, level of evidence 5 (95% and published in Asian (50% and North American (30% countries. There was an increase of the scientific production using models of structural equations during the study period and the predominance of investigations aimed at the work organization. The use of modeling of structural equations in nursing is growing. However, studies aimed at assistance and teaching are lacking. This method appeared useful for issues in research in this health field.

  14. Neutron scattering applications in structural biology: now and the future

    Energy Technology Data Exchange (ETDEWEB)

    Trewhella, J. [Los Alamos National Lab., NM (United States)

    1996-05-01

    Neutrons have an important role to play in structural biology. Neutron crystallography, small-angle neutron scattering and inelastic neutron scattering techniques all contribute unique information on biomolecular structures. In particular, solution scattering techniques give critical information on the conformations and dispositions of the components of complex assemblies under a wide variety of relevant conditions. The power of these methods is demonstrated here by studies of protein/DNA complexes, and Ca{sup 2+}-binding proteins complexed with their regulatory targets. In addition, we demonstrate the utility of a new structural approach using neutron resonance scattering. The impact of biological neutron scattering to date has been constrained principally by the available fluxes at neutron sources and the true potential of these approaches will only be realized with the development of new more powerful neutron sources. (author)

  15. Data Science and Political Economy: Application to Financial Regulatory Structure

    Directory of Open Access Journals (Sweden)

    Sharyn O'Halloran

    2016-11-01

    Full Text Available The development of computational data science techniques in natural language processing and machine learning algorithms to analyze large and complex textual information opens new avenues for studying the interaction between economics and politics. We apply these techniques to analyze the design of financial regulatory structure in the United States since 1950. The analysis focuses on the delegation of discretionary authority to regulatory agencies in promulgating, implementing, and enforcing financial sector laws and overseeing compliance with them. Combining traditional studies with the new machine learning approaches enables us to go beyond the limitations of both methods and offer a more precise interpretation of the determinants of financial regulatory structure.

  16. Spectrally-Selective Photonic Structures for PV Applications

    Directory of Open Access Journals (Sweden)

    Benedikt Bläsi

    2010-01-01

    Full Text Available We review several examples of how spectrally-selective photonic structures may be used to improve solar cell systems. Firstly, we introduce different spectrally-selective structures that are based on interference effects. Examples shown include Rugate filter, edge filter and 3D photonic crystals such as artificial opals. In the second part, we discuss several examples of photovoltaic (PV concepts that utilize spectral selectivity such as fluorescence collectors, upconversion systems, spectrum splitting concepts and the intermediate reflector concept. The potential of spectrally selective filters in the context of solar cells is discussed.

  17. Structural Reliability of Plain Bearings for Wave Energy Converter Applications

    DEFF Research Database (Denmark)

    Ambühl, Simon; Kramer, Morten Mejlhede; Sørensen, John Dalsgaard

    2016-01-01

    The levelized cost of energy (LCOE) from wave energy converters (WECs) needs to be decreased in order to be able to become competitive with other renewable electricity sources. Probabilistic reliability methods can be used to optimize the structure of WECs. Optimization is often performed...... for critical structural components, like welded details, bolts or bearings. This paper considers reliability studies with a focus on plain bearings available from stock for the Wavestar device, which exists at the prototype level. The Wavestar device is a point absorber WEC. The plan is to mount a new power...

  18. Global Structure-from-Motion and Its Application

    OpenAIRE

    Cui, Zhaopeng

    2017-01-01

    Structure-from-motion (SfM) is a fundamental problem in 3D computer vision, with the aim of recovering camera poses and 3D scene structure simultaneously given a set of 2D images. SfM methods can be broadly divided into incremental and global methods according to their ways to register cameras. Incremental methods register cameras one by one, while global SfM methods solve all cameras simultaneously from all available relative motions. As a result, global SfM has better potential in both reco...

  19. The Application of Classification Structures in Knowledge Organization and Representation

    Directory of Open Access Journals (Sweden)

    Tzu-heng Chiu

    2002-12-01

    Full Text Available Classification is a way of seeing the world. In a classification scheme, phenomena of interest are represented in a context of relationships that provide description, explanation, prediction, heuristics, and the generation of new knowledge. Knowing that information organization isn’t equal to knowledge organization, the author first defines the scope of classification and knowledge organization, and then describes the relationship between the classification and the representation and organization of knowledge. At the end, four kinds of classification structures are compared to show their abilities in representing knowledge. In order to utilize these classification structures, it is very important to understand their advantages and disadvantages.[Article content in Chinese

  20. Model optimizing production structure of coal enterprise and its application

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Q. [China University of Mining and Technology, Xuzhou (China). College of Business and Adminsitration

    2000-05-01

    The models which optimize the product structure and maximize the profit of a coal enterprise were established. These models are mainly the increment and total analysis model for determining the optimum coal preparation scheme, the model of management risk analysis, and the linear plan model for deciding the optimum product structure under the condition of a given technology. They have been applied to coal enterprise in practice and obtained obvious economic benefit. This shows that the models are scientifically reasonable and efficient, and are valuable in designing preparation plant and in planning production under the condition of market economy. 2 refs., 2 tabs.

  1. Application of global elements to a reinforced concrete structure; Application des elements globaux a une structure en beton arme

    Energy Technology Data Exchange (ETDEWEB)

    Morand, O

    1994-07-01

    The dimensioning of nuclear facilities requires to take into account the possible risk of earthquakes. However such installations are generally complex structures with reinforced concrete poles, walls, beams and porches. In this study, a seismic analysis of such a structure is proposed. The use of the Castem 2000 global element code was attempted to dynamically simulate the behaviour of the reinforced concrete elements. However, no suitable modeling has been found for the storeys, the functioning of which being dominated by carrying walls. Concerning the porch-type storeys, monotonous static loads were simulated and provided information on the local and global behaviour of these structures. Thus, representative global elements could be realized for these structures. Results obtained are satisfactory for these storeys which essentially undergo a bending deformation. (J.S.)

  2. 78 FR 52841 - Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Airplanes

    Science.gov (United States)

    2013-08-27

    ... Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Airplanes AGENCY... airworthiness directive (AD) for all Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model L... this AD, contact Lockheed Martin Corporation/Lockheed Martin Aeronautics Company, L-1011 Technical...

  3. 76 FR 82106 - Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Airplanes

    Science.gov (United States)

    2011-12-30

    ... Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Airplanes AGENCY... airworthiness directive (AD) for certain Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model L..., Lockheed Martin Corporation/Lockheed Martin Aeronautics Company, Airworthiness Office, Dept. 6A0M, Zone...

  4. 76 FR 58416 - Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model L...

    Science.gov (United States)

    2011-09-21

    ... Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model L-1011 Series... Martin Corporation/Lockheed Martin Aeronautics Company, Airworthiness Office, Dept. 6A0M, Zone 0252... Martin Corporation/Lockheed Martin Aeronautics Company: Docket No. FAA-2011-0919; Directorate Identifier...

  5. 3 CFR - Designation of Officers of the National Aeronautics And Space Administration To Act as Administrator

    Science.gov (United States)

    2010-01-01

    ... 3 The President 1 2010-01-01 2010-01-01 false Designation of Officers of the National Aeronautics... Memorandum of January 16, 2009 Designation of Officers of the National Aeronautics And Space Administration To Act as Administrator Memorandum for the Administrator of the National Aeronautics and Space...

  6. 75 FR 262 - Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model...

    Science.gov (United States)

    2010-01-05

    ... Corporation/Lockheed Martin Aeronautics Company Model 382, 382B, 382E, 382F, and 382G Airplanes AGENCY... Aeronautics Company Model 382, 382B, 382E, 382F, and 382G airplanes. This proposed AD would require repetitive... proposed AD, contact Lockheed Martin Corporation/Lockheed Martin Aeronautics Company, Airworthiness Office...

  7. 76 FR 22311 - Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model...

    Science.gov (United States)

    2011-04-21

    ... Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model 382, 382B, 382E... Martin Aeronautics Company, Airworthiness Office, Dept. 6A0M, Zone 0252, Column P-58, 86 S. Cobb Drive... Lockheed Martin Corporation/Lockheed Martin Aeronautics Company: Amendment 39-16665. Docket No. FAA-2010...

  8. 75 FR 36722 - Aeronautics Science and Technology Subcommittee; Committee on Technology; National Science and...

    Science.gov (United States)

    2010-06-28

    ... OFFICE OF SCIENCE AND TECHNOLOGY POLICY Aeronautics Science and Technology Subcommittee; Committee... requested to assist in the development of the draft National Aeronautics Research, Development, Test and Evaluation (RDT&E) Infrastructure Plan. SUMMARY: The Aeronautics Science and Technology Subcommittee (ASTS...

  9. 76 FR 48049 - Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model L...

    Science.gov (United States)

    2011-08-08

    ... Corporation/Lockheed Martin Aeronautics Company Model L-1011 Series Airplanes AGENCY: Federal Aviation... Lockheed Martin Corporation/Lockheed Martin Aeronautics Company, Airworthiness Office, Dept. 6A0M, Zone... Aeronautics Company: Docket No. FAA-2011-0723; Directorate Identifier 2010-NM-080-AD. Comments Due Date (a...

  10. 77 FR 63275 - Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Airplanes

    Science.gov (United States)

    2012-10-16

    ... Corporation/Lockheed Martin Aeronautics Company Airplanes AGENCY: Federal Aviation Administration (FAA), DOT... directive (AD) that applies to all Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model L.../Lockheed Martin Aeronautics Company, Airworthiness Office, Dept. 6A0M, Zone 0252, Column P-58, 86 S. Cobb...

  11. 75 FR 81678 - Aeronautics Science and Technology Subcommittee; Committee on Technology; National Science and...

    Science.gov (United States)

    2010-12-28

    ... OFFICE OF SCIENCE AND TECHNOLOGY POLICY Aeronautics Science and Technology Subcommittee; Committee... requested on the National Aeronautics Research, Development, Test and Evaluation (RDT&E) Infrastructure Plan. SUMMARY: The Aeronautics Science and Technology Subcommittee (ASTS) of the National Science and Technology...

  12. 76 FR 66350 - Eighth Meeting: RTCA Special Committee 222 Inmarsat Aeronautical Mobile Satellite (Route) Services

    Science.gov (United States)

    2011-10-26

    ... Committee 222 Inmarsat Aeronautical Mobile Satellite (Route) Services AGENCY: Federal Aviation..., Inmarsat Aeronautical Mobile Satellite (Route) Services meeting. SUMMARY: The FAA is issuing this notice to... Aeronautical Mobile Satellite (Route) Services. The agenda will include the following: Agenda November 17, 2011...

  13. 77 FR 48584 - Tenth Meeting: RTCA Special Committee 222, Inmarsat Aeronautical Mobile Satellite (Route) Services

    Science.gov (United States)

    2012-08-14

    ... 222, Inmarsat Aeronautical Mobile Satellite (Route) Services AGENCY: Federal Aviation Administration..., Inmarsat Aeronautical Mobile Satellite (Route) Services. SUMMARY: The FAA is issuing this notice to advise the public of the tenth meeting of RTCA Special Committee 222, Inmarsat Aeronautical Mobile Satellite...

  14. 77 FR 30046 - Ninth Meeting: RTCA Special Committee 222, Inmarsat Aeronautical Mobile Satellite (Route) Services

    Science.gov (United States)

    2012-05-21

    ... 222, Inmarsat Aeronautical Mobile Satellite (Route) Services AGENCY: Federal Aviation Administration..., Inmarsat Aeronautical Mobile Satellite (Route) Services. SUMMARY: The FAA is issuing this notice to advise the public of the Ninth meeting of RTCA Special Committee 222, Inmarsat Aeronautical Mobile Satellite...

  15. Emerging Definition of Next-Generation of Aeronautical Communications

    Science.gov (United States)

    Kerczewski, Robert J.

    2006-01-01

    Aviation continues to experience rapid growth. In regions such as the United States and Europe air traffic congestion is constraining operations, leading to major new efforts to develop methodologies and infrastructures to enable continued aviation growth through transformational air traffic management systems. Such a transformation requires better communications linking airborne and ground-based elements. Technologies for next-generation communications, the required capacities, frequency spectrum of operation, network interconnectivity, and global interoperability are now receiving increased attention. A number of major planning and development efforts have taken place or are in process now to define the transformed airspace of the future. These activities include government and industry led efforts in the United States and Europe, and by international organizations. This paper will review the features, approaches, and activities of several representative planning and development efforts, and identify the emerging global consensus on requirements of next generation aeronautical communications systems for air traffic control.

  16. Applied simulation and optimization in logistics, industrial and aeronautical practice

    CERN Document Server

    Mota, Idalia; Serrano, Daniel

    2015-01-01

    Presenting techniques, case-studies and methodologies that combine the use of simulation approaches with optimization techniques for facing problems in manufacturing, logistics, or aeronautical problems, this book provides solutions to common industrial problems in several fields, which range from manufacturing to aviation problems, where the common denominator is the combination of simulation’s flexibility with optimization techniques’ robustness. Providing readers with a comprehensive guide to tackle similar issues in industrial environments, this text explores novel ways to face industrial problems through hybrid approaches (simulation-optimization) that benefit from the advantages of both paradigms, in order to give solutions to important problems in service industry, production processes, or supply chains, such as scheduling, routing problems and resource allocations, among others.

  17. Unified first wall - blanket structure for plasma device applications

    Science.gov (United States)

    Gruen, D.M.

    A plasma device is described for use in controlling nuclear reactions within the plasma including a first wall and blanket formed in a one-piece structure composed of a solid solution containing copper and lithium and melting above about 500/sup 0/C.

  18. Structure modification of natural zeolite for waste removal application

    Science.gov (United States)

    Widayatno, W. B.

    2018-03-01

    Tremendous industrialization in the last century has led to the generation of huge amount of waste. One of the recent hot research topics is utilizing any advance materials and methods for waste removal. Natural zeolite as an inexpensive porous material with a high abundance holds a key for efficient waste removal owing to its high surface area. However, the microporous structure of natural zeolite hinders the adsorption of waste with a bigger molecular size. In addition, the recovery of natural zeolite after waste adsorption into its pores should also be considered for continuous utilization of this material. In this study, the porosity of natural zeolite from Tasikmalaya, Indonesia, was hydrothermally-modified in a Teflon-lined autoclave filled with certain pore directing agent such as distilled water, KOH, and NH4OH to obtain hierarchical pore structure. After proper drying process, the as-treated natural zeolite is impregnated with iron cation and heat-treated at specified temperature to get Fe-embedded zeolite structure. XRD observation is carried out to ensure the formation of magnetic phase within the zeolite pores. The analysis results show the formation of maghemite phase (γ-Fe2O3) within the zeolite pore structure.

  19. Adsorbed Polymer Nanolayers on Solids: Mechanism, Structure and Applications

    Science.gov (United States)

    Sen, Mani Kuntal

    In this thesis, by combining various advanced x-ray scattering, spectroscopic and other surface sensitive characterization techniques, I report the equilibrium polymer chain conformations, structures, dynamics and properties of polymeric materials at the solid-polymer melt interfaces. Following the introduction, in chapter 2, I highlight that the backbone chains (constituted of CH and CH2 groups) of the flattened polystyrene (PS) chains preferentially orient normal to the weakly interactive substrate surface via thermal annealing regardless of the initial chain conformations, while the orientation of the phenyl rings becomes randomized, thereby increasing the number of surface-segmental contacts (i.e., enthalpic gain) which is the driving force for the flattening process of the polymer chains even onto a weakly interactive solid. In chapter 3, I elucidate the flattened structures in block copolymer (BCP) thin films where both blocks lie flat on the substrate, forming a 2D randomly phase-separated structure irrespective of their microdomain structures and interfacial energetics. In chapter 4, I reveal the presence of an irreversibly adsorbed BCP layer which showed suppressed dynamics even at temperatures far above the individual glass transition temperatures of the blocks. Furthermore, this adsorbed BCP layer plays a crucial role in controlling the microdomain orientation in the entire film. In chapter 5, I report a radically new paradigm of designing a polymeric coating layer of a few nanometers thick ("polymer nanolayer") with anti-biofouling properties.

  20. Structural investigations of Great Basin geothermal fields: Applications and implications

    Energy Technology Data Exchange (ETDEWEB)

    Faulds, James E [Nevada Bureau of Mines and Geology, Univ. of Nevada, Reno, NV (United States); Hinz, Nicholas H. [Nevada Bureau of Mines and Geology, Univ. of Nevada, Reno, NV (United States); Coolbaugh, Mark F [Great Basin Center for Geothermal Energy, Univ. of Nevada, Reno, NV (United States)

    2010-11-01

    Because fractures and faults are commonly the primary pathway for deeply circulating hydrothermal fluids, structural studies are critical to assessing geothermal systems and selecting drilling targets for geothermal wells. Important tools for structural analysis include detailed geologic mapping, kinematic analysis of faults, and estimations of stress orientations. Structural assessments are especially useful for evaluating geothermal fields in the Great Basin of the western USA, where regional extension and transtension combine with high heat flow to generate abundant geothermal activity in regions having little recent volcanic activity. The northwestern Great Basin is one of the most geothermally active areas in the USA. The prolific geothermal activity is probably due to enhanced dilation on N- to NNE-striking normal faults induced by a transfer of NW-directed dextral shear from the Walker Lane to NW-directed extension. Analysis of several geothermal fields suggests that most systems occupy discrete steps in normal fault zones or lie in belts of intersecting, overlapping, and/or terminating faults. Most fields are associated with steeply dipping faults and, in many cases, with Quaternary faults. The structural settings favoring geothermal activity are characterized by subvertical conduits of highly fractured rock along fault zones oriented approximately perpendicular to the WNW-trending least principal stress. Features indicative of these settings that may be helpful in guiding exploration for geothermal resources include major steps in normal faults, interbasinal highs, groups of relatively low discontinuous ridges, and lateral jogs or terminations of mountain ranges.

  1. Improving the Pedagogy of Capital Structure Theory: An Excel Application

    Science.gov (United States)

    Baltazar, Ramon; Maybee, Bryan; Santos, Michael R.

    2012-01-01

    This paper uses Excel to enhance the pedagogy of capital structure theory for corporate finance instructors and students. We provide a lesson plan that utilizes Excel spreadsheets and graphs to develop understanding of the theory. The theory is introduced in three scenarios that utilize Modigliani & Miller's Propositions and…

  2. Ranking beta sheet topologies with applications to protein structure prediction

    DEFF Research Database (Denmark)

    Fonseca, Rasmus; Helles, Glennie; Winter, Pawel

    2011-01-01

    One reason why ab initio protein structure predictors do not perform very well is their inability to reliably identify long-range interactions between amino acids. To achieve reliable long-range interactions, all potential pairings of ß-strands (ß-topologies) of a given protein are enumerated, in...

  3. Lincosamides: Chemical structure, biosynthesis, mechanism of action, resistance, and applications

    Czech Academy of Sciences Publication Activity Database

    Spížek, Jaroslav; Řezanka, Tomáš

    2017-01-01

    Roč. 133, June 1 SI (2017), s. 20-28 ISSN 0006-2952 Institutional support: RVO:61388971 Keywords : Lincosamides * Chemical structure * Biosynthesis and mechanism of action Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.581, year: 2016

  4. Soil food web structure after wood ash application

    DEFF Research Database (Denmark)

    Mortensen, Louise Hindborg; Qin, Jiayi; Cruz-Paredes, Carla

    concentrations to experimental plots in a coniferous forest the soil will be collected with varying intervals and subsequently analyzed. The food web included several trophic levels; bacteria/fungi, protozoa, nematodes, enchytraeids and microarthropods and arthropods. Results from 2014 indicated that bacteria...... the consequences of returning wood ash to biofuel producing coniferous forest. We that the change in pH and increased availability of nutrients after ash application to forest floor can facilitate an increase in the bacteria to fungi ratio with possible effects for the soil food by applying ash of different...... and protozoa were stimulated in the uppermost soil layer (0-3 cm) two months ash application, whereas the enchytraeids seemed to be slightly negatively affected. Generally, nematodes also appeared to be negatively affected, although it differed between feeding groups. On the higher trophic levels, no effect...

  5. Shell-like structures advanced theories and applications

    CERN Document Server

    Eremeyev, Victor

    2017-01-01

    The book presents mathematical and mechanical aspects of the theory of plates and shells, applications in civil, aero-space and mechanical engineering, as well in other areas. The focus relates to the following problems: • comprehensive review of the most popular theories of plates and shells, • relations between three-dimensional theories and two-dimensional ones, • presentation of recently developed new refined plates and shells theories (for example, the micropolar theory or gradient-type theories), • modeling of coupled effects in shells and plates related to electromagnetic and temperature fields, phase transitions, diffusion, etc., • applications in modeling of non-classical objects like, for example, nanostructures, • presentation of actual numerical tools based on the finite element approach.

  6. Application of the Theory of Constraints in Project Based Structures

    OpenAIRE

    Martynas Sarapinas; Vytautas Pranas Sūdžius

    2011-01-01

    The article deals with the application of the Theory of Constraints (TOC) in project management. This article involves a short introduction to TOC as a project management method and deep analysis of project management specialties using the TOC: TOC based project planning, timetable management, tasks synchronization, project control and “relay runner work ethic”. Moreover, the article describes traditional and TOC based project management theories in their comparison, and emphasize the main be...

  7. Analysing innovation policy indicators through a functional approach: the aeronautic industry case

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, C.R.; Uriona Maldonado, M.

    2016-07-01

    Developing countries face different problems than developed countries and the use of the same indicator to evaluate and compare both regions can lead to misleading conclusions. Traditional indicators, such as R&D and patents may not capture the whole dynamic of a system, as they are used to compare systems focusing on its current structure. Many authors have been discussing the processes underlying industry transformation, innovation, and economic growth to access a system performance, i.e. the functions of innovation systems. Therefore, the purpose of this paper is to analyze these functions as indicators to measure the performance of the system in order to identify policy issues. In order to do that, we analyze the case of the aeronautic sectoral system of innovation of a region in Brazil. The functional approach helped us to better capture the dynamic of the system, by not restricting our analysis to the system’s structure. (Author)

  8. The AI Program at the National Aeronautics and Space Administration: Lessons Learned During the First Seven Years

    OpenAIRE

    Montemerlo, Melvin D.

    1992-01-01

    This article is a slightly modified version of an invited address that was given at the Eighth IEEE Conference on Artificial Intelligence for Applications in Monterey, California, on 2 March 1992. It describes the lessons learned in developing and implementing the Artificial Intelligence Research and Development Program at the National Aeronautics and Space Administration (NASA). In so doing, the article provides a historical perspective of the program in terms of the stages it went through a...

  9. Ligand-protected gold clusters: the structure, synthesis and applications

    Science.gov (United States)

    Pichugina, D. A.; Kuz'menko, N. E.; Shestakov, A. F.

    2015-11-01

    Modern concepts of the structure and properties of atomic gold clusters protected by thiolate, selenolate, phosphine and phenylacetylene ligands are analyzed. Within the framework of the superatom theory, the 'divide and protect' approach and the structure rule, the stability and composition of a cluster are determined by the structure of the cluster core, the type of ligands and the total number of valence electrons. Methods of selective synthesis of gold clusters in solution and on the surface of inorganic composites based, in particular, on the reaction of Aun with RS, RSe, PhC≡C, Hal ligands or functional groups of proteins, on stabilization of clusters in cavities of the α-, β and γ-cyclodextrin molecules (Au15 and Au25) and on anchorage to a support surface (Au25/SiO2, Au20/C, Au10/FeOx) are reviewed. Problems in this field are also discussed. Among the methods for cluster structure prediction, particular attention is given to the theoretical approaches based on the density functional theory (DFT). The structures of a number of synthesized clusters are described using the results obtained by X-ray diffraction analysis and DFT calculations. A possible mechanism of formation of the SR(AuSR)n 'staple' units in the cluster shell is proposed. The structure and properties of bimetallic clusters MxAunLm (M=Pd, Pt, Ag, Cu) are discussed. The Pd or Pt atom is located at the centre of the cluster, whereas Ag and Cu atoms form bimetallic compounds in which the heteroatom is located on the surface of the cluster core or in the 'staple' units. The optical properties, fluorescence and luminescence of ligand-protected gold clusters originate from the quantum effects of the Au atoms in the cluster core and in the oligomeric SR(AuSR)x units in the cluster shell. Homogeneous and heterogeneous reactions catalyzed by atomic gold clusters are discussed in the context of the reaction mechanism and the nature of the active sites. The bibliography includes 345 references.

  10. Evaluation of network structures and protocols for nuclear-specific applications

    International Nuclear Information System (INIS)

    Zahedi, P.

    2008-01-01

    The evaluation of industrial implementations of network structures associated with nuclear-specific applications is the main focus of this paper. Establishing numerous network structures currently used in nuclear industry, this project analyzes the functionality and reliability of different structures. The communication structures studied in this paper include Fieldbus and Modbus Communication Protocols, Object Linking and Embedding process control (OPC), Dynamic Data Exchange (DDE) and Net-DDE. This paper focuses on identifying the potential problems in applying various network structures to nuclear industry to enable a nuclear-specific network structure to be developed for the fast growing nuclear industry. (author)

  11. Structural materials for high-heat flux applications

    International Nuclear Information System (INIS)

    Rybin, V.V.; Smith, D.L.

    1991-01-01

    The structural materials for the ITER, (International Thermonuclear Experimental Reactor) divertor must perform reliably under complex and diverse operating requirements. Only a limited number of materials offer a potential for meeting these requirements for the wide temperature range of interest. The candidate materials considered in the ITER design activity include copper, molybdenum, niobium alloys. Molybdenum alloys being considered include dilute alloys of the TZM type and the Mo-Re system. Niobium alloys under consideration include Nb-V-Zr and Nb-Zr systems. Copper alloys being considered include precipitation strengthened alloys of the Glidcop and MAGT type, alloys of Cu-Mo system and dispersion hardened bronzes. The projected operating conditions for the ITER divertor and the criteria for evaluating the candidate materials are reviewed. This paper summarizes the data base and presents recent experimental results on these candidate divertor structural alloys

  12. Adaptive Distributed Data Structure Management for Parallel CFD Applications

    KAUST Repository

    Frisch, Jerome

    2013-09-01

    Computational fluid dynamics (CFD) simulations require a lot of computing resources in terms of CPU time and memory in order to compute with a reasonable physical accuracy. If only uniformly refined domains are applied, the amount of computing cells is growing rather fast if a certain small resolution is physically required. This can be remedied by applying adaptively refined grids. Unfortunately, due to the adaptive refinement procedures, errors are introduced which have to be taken into account. This paper is focussing on implementation details of the applied adaptive data structure management and a qualitative analysis of the introduced errors by analysing a Poisson problem on the given data structure, which has to be solved in every time step of a CFD analysis. Furthermore an adaptive CFD benchmark example is computed, showing the benefits of an adaptive refinement as well as measurements of parallel data distribution and performance. © 2013 IEEE.

  13. Application of ellipsometric and interference methods in MOS structures investigations

    Energy Technology Data Exchange (ETDEWEB)

    Rzodkiewicz, W; Borowicz, L; Piskorski, K [Institute of Electron Technology, Al. Lotnikow 32/46, 02-668 Warsaw (Poland)

    2007-04-15

    Changes in some electrical and photoelectric parameters in the plane of aluminum gate, particularly in the effective contact potential difference (ECPD or {phi}{sub MS} factor) have been observed in MOS System Studies Department of Institute of Electron Technology for the first time. It has been found that the MS distribution over the gate area has a characteristic domelike shape, with the highest values ate the center of the gate, lower at the gate edges and still lower at gate corners. In order to find out why these values were changed in such way, we have investigated optical properties of the dielectric in the neighborhood of metal gate. Hence, in this work, interferometry and spectroscopic ellipsometry as well as scattered Raman radiation analysis have been used in the investigation of metal-oxide-semiconductor (MOS) structures. The above mentioned methods turned out to be very useful for the possible explanation of changes in photoelectric characteristics of MOS structures with aluminum gate.

  14. Application of ellipsometric and interference methods in MOS structures investigations

    Science.gov (United States)

    Rzodkiewicz, W.; Borowicz, L.; Piskorski, K.

    2007-04-01

    Changes in some electrical and photoelectric parameters in the plane of aluminum gate, particularly in the effective contact potential difference (ECPD or phiMS factor) have been observed in MOS System Studies Department of Institute of Electron Technology for the first time. It has been found that the MS distribution over the gate area has a characteristic domelike shape, with the highest values ate the center of the gate, lower at the gate edges and still lower at gate corners. In order to find out why these values were changed in such way, we have investigated optical properties of the dielectric in the neighborhood of metal gate. Hence, in this work, interferometry and spectroscopic ellipsometry as well as scattered Raman radiation analysis have been used in the investigation of metal-oxide-semiconductor (MOS) structures. The above mentioned methods turned out to be very useful for the possible explanation of changes in photoelectric characteristics of MOS structures with aluminum gate.

  15. Semantic structure tree with application to remote sensing image segmentation

    Science.gov (United States)

    Zhang, Xiangrong; Pan, Xian; Hou, Biao; Jiao, Licheng

    2010-10-01

    This paper presents a new method based on Semantic Structure Tree (SST) for remote sensing image segmentation, in which, the semantic image analysis is used to construct the SST of the image. The leaves of the SST represent the semantics of the image and serve as human semantic understanding of the image. The root of the tree is the whole image. The SST uses grammar rules to construct a hierarchy structure of the image and gives a complete high-level semantics contents description of the image. Experimental results show that the tree can give efficient description of the semantic content of the remote sensing image, and can be well used in remote sensing image segmentation.

  16. Plasmonic nanopillar structures for surface-enhanced raman scattering applications

    DEFF Research Database (Denmark)

    Rindzevicius, Tomas; Schmidt, Michael Stenbæk; Wu, Kaiyu

    2016-01-01

    Noble metal nanostructures support localized surface plasmon (LSPR) resonances that depend on their dimensions, shapes and compositions. Particle LSPR's can be used to spatially confine the incident light and produce enormous electromagnetic (EM) field enhancement spots, i.e. hot spots. Hot spots...... have been utilized in surfaceenhanced Raman spectroscopy (SERS) for biological and chemical sensing. We present Au nanopillar (NP) SERS structures that are excellent for molecular detection. The NP structures can be fabricated using a simple two-step process. We analyze NP optical properties...... experimentally and theoretically. Simulations show that that a single Agcoated NP supports two LSPR modes, i.e. the particle mode and the Ag cap resonant cavity mode. The Ag cap resonant cavity mode contributes most to the enhancement of the Raman scattering signal. The electric field distribution calculations...

  17. Application of fluorine NMR for structure identification of steroids.

    Science.gov (United States)

    Ampt, Kirsten A M; Aspers, Ruud L E G; Jaeger, Martin; Geutjes, Pepijn E T J; Honing, Maarten; Wijmenga, Sybren S

    2011-05-01

    Fluorinated steroids were examined using 1D and 2D homo- and heteronuclear (19)F NMR, such as (19)F-(1) H and (19)F-(13)C. The utilization of fluorine NMR accounted for spectral simplification and resulted in a straightforward pathway for the determination of structures including the configuration of these compounds; these steroids present an illustrative example for other types of fluorinated compounds, which are increasingly encountered in drug discovery. The potential of (19)F NMR is elaborated on in detail for two compounds containing diastereotopic fluorines with different coupling patterns. The analysis of the coupling patterns and the through-space interactions resulted in the determination of the structure and configuration. Heteronuclear correlation experiments, i.e. (19)F-(1)H HETCOR, (19)F-(13)C HMQC and HMBC, and (19)F-(1)H HOESY, were applied to determine first the relative stereochemistry and then the molecular configuration at C4 and C5 of a steroidal compound bearing a fused three-membered ring with two fluorine substituents. These examples proved (19)F NMR to be a useful addition to the extensively used (1)H and (13)C NMR within structure elucidation and configuration determination of small molecules. Copyright © 2011 John Wiley & Sons, Ltd.

  18. MOS structures containing silicon nanoparticles for memory device applications

    Energy Technology Data Exchange (ETDEWEB)

    Nedev, N; Zlatev, R [Instituto de IngenierIa, Universidad Autonoma de Baja California, Benito Juarez Blvd., s/n, C.P. 21280, Mexicali, Baja California (Mexico); Nesheva, D; Manolov, E; Levi, Z [Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee, 1784 Sofia (Bulgaria); Brueggemann, R; Meier, S [Institute of Physics, Carl von Ossietzky University, Oldenburg, D-26111 Oldenburg (Germany)], E-mail: nicola@iing.mxl.uabc.mx

    2008-05-01

    Metal-oxide-silicon structures containing layers with amorphous or crystalline silicon nanoparticles in a silicon oxide matrix are fabricated by sequential physical vapour deposition of SiO{sub x} (x = 1.15) and RF sputtering of SiO{sub 2} on n-type crystalline silicon, followed by high temperature annealing in an inert gas ambient. Depending on the annealing temperature, 700 deg. C or 1000 deg. C, amorphous or crystalline silicon nanoparticles are formed in the silicon oxide matrix. The annealing process is used not only for growing nanoparticles but also to form a dielectric layer with tunnelling thickness at the silicon/insulator interface. High frequency C-V measurements demonstrate that both types of structures can be charged negatively or positively by applying a positive or negative voltage on the gate. The structures with amorphous silicon nanoparticles show several important advantages compared to the nanocrystal ones, such as lower defect density at the interface between the crystalline silicon wafer and the tunnel silicon oxide, better retention characteristics and better reliability.

  19. Future device applications of low-dimensional carbon superlattice structures

    Science.gov (United States)

    Bhattacharyya, Somnath

    2005-03-01

    We observe superior transport properties in low-dimensional amorphous carbon (a-C) and superlattice structures fabricated by a number of different techniques. Low temperature conductivity of these materials is explained using argument based on the crossover of dimensionality of weak localization and electron-electron interactions along with a change of sign of the magneto-resistance. These trends are significantly different from many other well characterized ordered or oriented carbon structures, and, show direct evidence of high correlation length, mobility and an effect of the dimensionality in low-dimensional a-C films. We show routes to prepare bespoke features by tuning the phase relaxation time in order to make high-speed devices over large areas. The artificially grown multi-layer superlattice structures of diamond-like amorphous carbon films show high-frequency resonance and quantum conductance suggesting sufficiently high values of phase coherence length in the present disordered a-C system that could lead to fast switching multi-valued logic.

  20. Topographic mapping of oral structures - problems and applications in prosthodontics

    Science.gov (United States)

    Young, John M.; Altschuler, Bruce R.

    1981-10-01

    The diagnosis and treatment of malocclusion, and the proper design of restorations and prostheses, requires the determination of surface topography of the teeth and related oral structures. Surface contour measurements involve not only affected teeth, but adjacent and opposing surface contours composing a complexly interacting occlusal system. No a priori knowledge is predictable as dental structures are largely asymmetrical, non-repetitive, and non-uniform curvatures in 3-D space. Present diagnosis, treatment planning, and fabrication relies entirely on the generation of physical replicas during each stage of treatment. Fabrication is limited to materials that lend themselves to casting or coating, and to hand fitting and finishing. Inspection is primarily by vision and patient perceptual feedback. Production methods are time-consuming. Prostheses are entirely custom designed by manual methods, require costly skilled technical labor, and do not lend themselves to centralization. The potential improvement in diagnostic techniques, improved patient care, increased productivity, and cost-savings in material and man-hours that could result, if rapid and accurate remote measurement and numerical (automated) fabrication methods were devised, would be significant. The unique problems of mapping oral structures, and specific limitations in materials and methods, are reviewed.

  1. V-amylose structural characteristics, methods of preparation, significance, and potential applications

    CSIR Research Space (South Africa)

    Obiro, WC

    2012-02-01

    Full Text Available , and postprandial hyperglycaemia in diabetics. Various aspects of V-amylose structure, methods of preparation, factors that affect its formation, and the significance and potential applications of the V-amylose complexes are reviewed....

  2. EXAFS (Extended X-Ray Absorption Fine Structure): theory and applications

    International Nuclear Information System (INIS)

    Lagarde, P.; Raoux, D.

    1984-01-01

    EXAFS (Extended X-Ray Absorption Fine Structure) is introduced in a general way and the qualities of such a techique are shown. Some examples of applications of EXAFS in several branches of science are presented. (L.C.) [pt

  3. Application of Generalized Mie Theory to EELS Calculations as a Tool for Optimization of Plasmonic Structures

    DEFF Research Database (Denmark)

    Thomas, Stefan; Matyssek, Christian; Hergert, Wolfram

    2015-01-01

    Technical applications of plasmonic nanostructures require a careful structural optimization with respect to the desired functionality. The success of such optimizations strongly depends on the applied method. We extend the generalized multiparticle Mie (GMM) computational electromagnetic method...

  4. Synchrotron radiation : characteristics and application in structural studies and phase transformations of materials

    International Nuclear Information System (INIS)

    Craievich, A.F.

    1984-01-01

    The main characteristics of the synchrotron radiation for studying atomic structure and phase transformations in materials are presented. Some specific applications in alloys, glass and solids are described. (E.G.) [pt

  5. Bitopological spaces theory, relations with generalized algebraic structures and applications

    CERN Document Server

    Dvalishvili, Badri

    2005-01-01

    This monograph is the first and an initial introduction to the theory of bitopological spaces and its applications. In particular, different families of subsets of bitopological spaces are introduced and various relations between two topologies are analyzed on one and the same set; the theory of dimension of bitopological spaces and the theory of Baire bitopological spaces are constructed, and various classes of mappings of bitopological spaces are studied. The previously known results as well the results obtained in this monograph are applied in analysis, potential theory, general topology, a

  6. Application of the Theory of Constraints in Project Based Structures

    Directory of Open Access Journals (Sweden)

    Martynas Sarapinas

    2011-04-01

    Full Text Available The article deals with the application of the Theory of Constraints (TOC in project management. This article involves a short introduction to TOC as a project management method and deep analysis of project management specialties using the TOC: TOC based project planning, timetable management, tasks synchronization, project control and “relay runner work ethic”. Moreover, the article describes traditional and TOC based project management theories in their comparison, and emphasize the main benefits we received as the results of the study. Article in Lithuanian

  7. Organic structures design applications in optical and electronic devices

    CERN Document Server

    Chow, Tahsin J

    2014-01-01

    ""Presenting an overview of the syntheses and properties of organic molecules and their applications in optical and electronic devices, this book covers aspects concerning theoretical modeling for electron transfer, solution-processed micro- and nanomaterials, donor-acceptor cyclophanes, molecular motors, organogels, polyazaacenes, fluorogenic sensors based on calix[4]arenes, and organic light-emitting diodes. The publication of this book is timely because these topics have become very popular nowadays. The book is definitely an excellent reference for scientists working in these a

  8. A New Microstrip Filter Using CRLH Structure and Defected Ground Structure in Antenna Application

    Directory of Open Access Journals (Sweden)

    Xin Cao

    2014-01-01

    Full Text Available A new microstrip bandpass filter using composite right/left-handed (CRLH mushroom structure with interdigital capacitors and defected ground structure (DGS is proposed. The proposed filter uses CRLH mushroom structure working at its first negative resonance mode to create the passband and DGS to increase rejection outside the passband. Simulation and measurement results are in good agreement, and low in-band insertion loss and great out-band rejection have been achieved. It is demonstrated that the combination of CRLH mushroom structure with interdigital capacitors and DGS has succeeded in achieving excellent performance. This new filter can be applied in transmitting and receiving antennas.

  9. Graphene Based Nanomaterials: Synthesis and the Structural Applications

    Science.gov (United States)

    Cao, Linlin

    Along with the development of nanomaterials and nanotechnology, graphene has attracted great attention due to its outstanding mechanical, electrical, and physical properties. Graphene oxide (GO), as a derivative of graphene, has also attracted great attention, especially as reinforcements for strong and lightweight composites. The most widely used method to synthesize GO is Hummers' method, which involves hazardous chemicals and is a time-consuming process. In this thesis work, I will introduce a green and feasible process to produce GO and nitrogen-doped GO directly from bio-waste materials without catalyst or substrate. Their applications as oxygen reduction reaction catalyst in fuel cell and fast electroactive actuator will be demonstrated. Then I will explore GO's application in poly(dimethylsiloxane) (PDMS) composites and poly(acrylamide) (PAM) hydrogels. Through interfacial evolution, GO/PDMS composites and GO/PAM hydrogels will be able to stiffen in response to applied cyclic loads. It is shown that the hybrid chemical and physical crosslinking network plays a critical role in the dynamic self-stiffening response. These results provide insight into the complicated nature at the interface between polymer chains and GO, and will help to develop self-stiffening artificial muscle and soft robotics.

  10. Production and applications of rosmarinic acid and structurally related compounds.

    Science.gov (United States)

    Kim, Gun-Dong; Park, Yong Seek; Jin, Young-Ho; Park, Cheung-Seog

    2015-03-01

    Rosmarinic acid (α-o-caffeoyl-3,4-dihydroxyphenyllactic acid; RA) is a naturally occurring hydroxylated compound commonly found in species of the subfamily Nepetoideae of the Lamiaceae and Boraginaceae, such as Rosmarinus officinalis, Salvia officinalis, and Perilla frutescens. RA is biosynthesized from the amino acids L-phenylalanine and L-tyrosine by eight enzymes that include phenylalanine ammonia lyase and cinnamic acid 4-hydroxylase. RA can also be chemically produced by the esterification of caffeic acid and 3,4-dihydroxyphenyllactic acid. RA and its numerous derivatives containing one or two RA with other aromatic moieties are well known and include lithospermic acid, yunnaneic acid, salvianolic acid, and melitric acid. Recently, RA and its derivatives have attracted interest for their biological activities, which include anti-inflammatory, anti-oxidant, anti-angiogenic, anti-tumor, and anti-microbial functions. Clinically, RA attenuates T cell receptor-mediated signaling, attenuates allergic diseases like allergic rhinitis and asthma, and 2,4-dinitrofluorobenzene-induced atopic dermatitis-like symptoms, protects from neurotoxicity, and slows the development of Alzheimer's disease. These attributes have increased the demand for the biotechnological production and application of RA and its derivatives. The present review discusses the function and application of RA and its derivatives including the molecular mechanisms underlying clinical efficacy.

  11. Structural Reliability of Plain Bearings for Wave Energy Converter Applications

    Directory of Open Access Journals (Sweden)

    Simon Ambühl

    2016-02-01

    Full Text Available The levelized cost of energy (LCOE from wave energy converters (WECs needs to be decreased in order to be able to become competitive with other renewable electricity sources. Probabilistic reliability methods can be used to optimize the structure of WECs. Optimization is often performed for critical structural components, like welded details, bolts or bearings. This paper considers reliability studies with a focus on plain bearings available from stock for the Wavestar device, which exists at the prototype level. The Wavestar device is a point absorber WEC. The plan is to mount a new power take-off (PTO system consisting of a discrete displacement cylinder (DDC, which will allow different hydraulic cycles to operate at constant pressure levels. This setup increases the conversion efficiency, as well as decouples the electricity production from the pressure variations within the hydraulic cycle when waves are passing. The new PTO system leads to different load characteristics at the floater itself compared to the actual setup where the turbine/generator is directly coupled to the fluctuating hydraulic pressure within the PTO system. This paper calculates the structural reliability of the different available plain bearings planned to be mounted at the new PTO system based on a probabilistic approach, and the paper gives suggestions for fulfilling the minimal target reliability levels. The considered failure mode in this paper is the brittle fatigue failure of plain bearings. The performed sensitivity analysis shows that parameters defining the initial crack size have a big impact on the resulting reliability of the plain bearing.

  12. Receiver Function Imaging of Dipping Structures - Technique and Applications

    Science.gov (United States)

    Liu, H.; Niu, F.

    2010-12-01

    CCP Stacking is probably the most common technique in receiver function imaging. In this technique, the conversion points are calculated and binned by assuming horizontal interfaces. However, for dipping structures such as tilted Moho or subducting slab, the horizontal interface assumption breaks down so that the image quality is low and the interfaces are misplaced. In these cases, the CCP stacking is not effective because the true conversion points do not necessarily lie in the vertical planes defined by sources and receivers and the delay time of conversion signals are varying with back azimuth. Although pre-stack time migration is an ideal technique to make correct images, the amount of qualified data it requires is often not available. An alternative way is to gather receiver functions based on conversion points and conversion times calculated from 3D velocity models with dipping structures. A dipping interface is defined by depth (d0) at a fixed geographic location, strike (Φ) and dipping angle (α). For an assumed (d0, Φ, α), we computed the conversion locations and conversion times by 3D ray tracing. We varied the depth (d0) and the dipping geometry (Φ, α) in certain range and determined the optimum value that gives the best coherent stacking signals. Note based on different tectonic setting, one or both of the dipping parameters can be fixed in the grid searching. We applied this technique to the imaging of two different geologic structures. One is a subducting slab case in western Mexico where the Rivera plate is subducting under the North American plate. Receiver functions recorded by fifty broadband seismic stations deployed under the MARS project were used to image the subducting Rivera slab. The second case is a tilted Moho lying underneath the GSN station SDV located at the southern flank of the central Venezuelan Andes. In both cases, we found substantial improvements in the receiver function images using our 3D ray tracing technique.

  13. Perovskite solid electrolytes: Structure, transport properties and fuel cell applications

    DEFF Research Database (Denmark)

    Bonanos, N.; Knight, K.S.; Ellis, B.

    1995-01-01

    vapour transfer in a cell in which the perovskite is exposed to wet hydrogen on both sides. The evolution of transport properties with temperature is discussed in relation to structure. Neutron diffraction studies of doped and undoped barium cerate are reported, revealing a series of phase transitions......Doped barium cerate perovskites, first investigated by Iwahara and co-workers, have ionic conductivities of the order of 20 mS/cm at 800 degrees C making them attractive as fuel cell electrolytes for this temperature region. They have been used to construct laboratory scale fuel cells, which...

  14. Option chain and change management : a structural equation application.

    OpenAIRE

    Thierry Burger-Helmchen

    2006-01-01

    The aim of this work is to establish empirically with a structural equation model (SEM) the existence of links between the options perceived by the members of an industry, the expectation of future rents produced by the exercise of these options and firm or industry specific factors. The theoretical part of this work is based on the notion of option chain developed by Bowman and Hurry (1993). The empirical part is on the video-game industry. A questionnaire based dataset on 211 video-game cre...

  15. Soil food web structure after wood ash application

    DEFF Research Database (Denmark)

    Mortensen, L. H.; Qin, J.; Krogh, Paul Henning

    with varying intervals and subsequently analyzed. The food web analysis includes several trophic levels; bacteria/fungi, protozoa, nematodes, enchytraeids, microarthropods and arthropods. The initial results indicate that bacteria and protozoa are stimulated in the uppermost soil layer (0-3 cm) two months...... can facilitate an increase in the bacteria to fungi ratio with possible cascading effects for the soil food web structure. This is tested by applying ash of different concentrations to experimental plots in a coniferous forest. During the course of the project soil samples will be collected...

  16. Modern electronic structure theory and applications in organic chemistry

    CERN Document Server

    Davidson, ER

    1997-01-01

    This volume focuses on the use of quantum theory to understand and explain experiments in organic chemistry. High level ab initio calculations, when properly performed, are useful in making quantitative distinctions between various possible interpretations of structures, reactions and spectra. Chemical reasoning based on simpler quantum models is, however, essential to enumerating the likely possibilities. The simpler models also often suggest the type of wave function likely to be involved in ground and excited states at various points along reaction paths. This preliminary understanding is n

  17. Structure and application of antifreeze proteins from Antarctic bacteria.

    Science.gov (United States)

    Muñoz, Patricio A; Márquez, Sebastián L; González-Nilo, Fernando D; Márquez-Miranda, Valeria; Blamey, Jenny M

    2017-08-07

    Antifreeze proteins (AFPs) production is a survival strategy of psychrophiles in ice. These proteins have potential in frozen food industry avoiding the damage in the structure of animal or vegetal foods. Moreover, there is not much information regarding the interaction of Antarctic bacterial AFPs with ice, and new determinations are needed to understand the behaviour of these proteins at the water/ice interface. Different Antarctic places were screened for antifreeze activity and microorganisms were selected for the presence of thermal hysteresis in their crude extracts. Isolates GU1.7.1, GU3.1.1, and AFP5.1 showed higher thermal hysteresis and were characterized using a polyphasic approach. Studies using cucumber and zucchini samples showed cellular protection when samples were treated with partially purified AFPs or a commercial AFP as was determined using toluidine blue O and neutral red staining. Additionally, genome analysis of these isolates revealed the presence of genes that encode for putative AFPs. Deduced amino acids sequences from GU3.1.1 (gu3A and gu3B) and AFP5.1 (afp5A) showed high similarity to reported AFPs which crystal structures are solved, allowing then generating homology models. Modelled proteins showed a triangular prism form similar to β-helix AFPs with a linear distribution of threonine residues at one side of the prism that could correspond to the putative ice binding side. The statistically best models were used to build a protein-water system. Molecular dynamics simulations were then performed to compare the antifreezing behaviour of these AFPs at the ice/water interface. Docking and molecular dynamics simulations revealed that gu3B could have the most efficient antifreezing behavior, but gu3A could have a higher affinity for ice. AFPs from Antarctic microorganisms GU1.7.1, GU3.1.1 and AFP5.1 protect cellular structures of frozen food showing a potential for frozen food industry. Modeled proteins possess a β-helix structure, and

  18. Some applications of nanometer scale structures for current and future X-ray space research

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Abdali, S; Frederiksen, P K

    1994-01-01

    Nanometer scale structures such as multilayers, gratings and natural crystals are playing an increasing role in spectroscopic applications for X-ray astrophysics. A few examples are briefly described as an introduction to current and planned applications pursued at the Danish Space Research Insti...

  19. Therapeutic applications of reconstituted HDL: When structure meets function.

    Science.gov (United States)

    Darabi, Maryam; Guillas-Baudouin, Isabelle; Le Goff, Wilfried; Chapman, M John; Kontush, Anatol

    2016-01-01

    Reconstituted forms of HDL (rHDL) are under development for infusion as a therapeutic approach to attenuate atherosclerotic vascular disease and to reduce cardiovascular risk following acute coronary syndrome and ischemic stroke. Currently available rHDL formulations developed for clinical use contain apolipoprotein A-I (apoA-I) and one of the major lipid components of HDL, either phosphatidylcholine or sphingomyelin. Recent data have established that quantitatively minor molecular constituents of HDL particles can strongly influence their anti-atherogenic functionality. Novel rHDL formulations displaying enhanced biological activities, including cellular cholesterol efflux, may therefore offer promising prospects for the development of HDL-based, anti-atherosclerotic therapies. Indeed, recent structural and functional data identify phosphatidylserine as a bioactive component of HDL; the content of phosphatidylserine in HDL particles displays positive correlations with all metrics of their functionality. This review summarizes current knowledge of structure-function relationships in rHDL formulations, with a focus on phosphatidylserine and other negatively-charged phospholipids. Mechanisms potentially underlying the atheroprotective role of these lipids are discussed and their potential for the development of HDL-based therapies highlighted. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Structural Equation Modeling: Applications in ecological and evolutionary biology research

    Science.gov (United States)

    Pugesek, Bruce H.; von Eye, Alexander; Tomer, Adrian

    2003-01-01

    This book presents an introduction to the methodology of structural equation modeling, illustrates its use, and goes on to argue that it has revolutionary implications for the study of natural systems. A major theme of this book is that we have, up to this point, attempted to study systems primarily using methods (such as the univariate model) that were designed only for considering individual processes. Understanding systems requires the capacity to examine simultaneous influences and responses. Structural equation modeling (SEM) has such capabilities. It also possesses many other traits that add strength to its utility as a means of making scientific progress. In light of the capabilities of SEM, it can be argued that much of ecological theory is currently locked in an immature state that impairs its relevance. It is further argued that the principles of SEM are capable of leading to the development and evaluation of multivariate theories of the sort vitally needed for the conservation of natural systems. Supplementary information can be found at the authors website, http://www.jamesbgrace.com/. • Details why multivariate analyses should be used to study ecological systems • Exposes unappreciated weakness in many current popular analyses • Emphasizes the future methodological developments needed to advance our understanding of ecological systems.

  1. Application of fiber optic sensors to structural monitoring

    Science.gov (United States)

    Inaudi, Daniele

    2003-03-01

    The construction and maintenance of the civil infrastructure represents between 10% and 20% of the public investment in most European countries. In the last decade we have however witnessed an increasing shift from investments in the construction of new structures to the maintenance and the lifetime extension of the existing ones. With the exception of the high-speed train lines, most of the transporataion network, including highways and railway, is completed and in service. However, the steady increase of the passengers and goods circulating in the continent, amplified by the free circulation policy introduced by the European Community, is putting the civil infrastructrue under a rude test. Many bridges and tunnels built a few tens of years ago need repair and in many cases an extension of their bearing capacity and lifetime that exceed the original plans. Besides the direct costs associated with these interventions, the disruption to the normal use of the structures causes additional inconveniences including traffic jams and accidents that carry additional hidden costs.

  2. Copper oxide assisted cysteine hierarchical structures for immunosensor application

    Science.gov (United States)

    Pandey, Chandra Mouli; Sumana, Gajjala; Tiwari, Ida

    2014-09-01

    The present work describes the promising electrochemical immunosensing strategy based on copper (II) assisted hierarchical cysteine structures (CuCys) varying from star to flower like morphology. The CuCys having average size of 10 μm have been synthesised using L-Cysteine as initial precursor in presence of copper oxide under environmentally friendly conditions in aqueous medium. To delineate the synthesis mechanism, detailed structural investigations have been carried out using characterization techniques such as X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. The electrochemical behaviour of self-assembled CuCys on gold electrode shows surface controlled electrode reaction with an apparent electron transfer rate constant of 3.38 × 10-4 cm s-1. This innovative platform has been utilized to fabricate an immunosensor by covalently immobilizing monoclonal antibodies specific for Escherichia coli O157:H7 (E. coli). Under the optimal conditions, the fabricated immunosensor is found to be sensitive and specific for the detection of E. coli with a detection limit of 10 cfu/ml.

  3. A precision structured smart hydrogel for sensing applications

    Science.gov (United States)

    Menges, J.; Kleinschmidt, P.; Bart, H.-J.; Oesterschulze, E.

    2017-10-01

    We report on a macroinitiator based smart hydrogel film applied on a microcantilever for sensing applications. The studied hydrogel features a comparatively wide dynamic range for changes in the electrolyte's ionic strength. Furthermore, it offers a simple spin coating process for thin film deposition as well as the capability to obtain high aspect ratio microstructures by reactive ion etching. This makes the hydrogel compatible to microelectromechanical system integration. As a proof of concept, we study the response of hydrogel functionalized cantilevers in aqueous sodium chloride solutions of varying ionic strength. In contrast to the majority of hydrogel materials reported in the literature, we found that our hydrogel still responds in high ionic strength environments. This may be of future interest for sensing e.g., in sea water or physiological environments like urine.

  4. Advanced composite design data for spacecraft structural applications

    International Nuclear Information System (INIS)

    Haskins, J.F.

    1980-01-01

    An experimental study has been carried out to investigate the long-term effects of space environment on the mechanical properties and thermal expansion of two graphite/epoxy materials: T300/934, a high-strength system with a 350 F capability, and GY70/X30, an ultra-high-modulus system used for high-stiffness and thermally stable applications. The effects of space environment were simulated by exposing the materials to three levels of uniform radiation. Changes in mechanical properties due to radiation were small, except at high temperatures. Since radiation clearly lowered the glass transition temperature below the upper test temperature, both tensile and shear strengths were lowered at the elevated temperatures. There was also some indication that the lower radiation levels may even improve the mechanical properties, which however needs further investigation

  5. Distribution Agnostic Structured Sparsity Recovery: Algorithms and Applications

    KAUST Repository

    Masood, Mudassir

    2015-05-01

    Compressed sensing has been a very active area of research and several elegant algorithms have been developed for the recovery of sparse signals in the past few years. However, most of these algorithms are either computationally expensive or make some assumptions that are not suitable for all real world problems. Recently, focus has shifted to Bayesian-based approaches that are able to perform sparse signal recovery at much lower complexity while invoking constraint and/or a priori information about the data. While Bayesian approaches have their advantages, these methods must have access to a priori statistics. Usually, these statistics are unknown and are often difficult or even impossible to predict. An effective workaround is to assume a distribution which is typically considered to be Gaussian, as it makes many signal processing problems mathematically tractable. Seemingly attractive, this assumption necessitates the estimation of the associated parameters; which could be hard if not impossible. In the thesis, we focus on this aspect of Bayesian recovery and present a framework to address the challenges mentioned above. The proposed framework allows Bayesian recovery of sparse signals but at the same time is agnostic to the distribution of the unknown sparse signal components. The algorithms based on this framework are agnostic to signal statistics and utilize a priori statistics of additive noise and the sparsity rate of the signal, which are shown to be easily estimated from data if not available. In the thesis, we propose several algorithms based on this framework which utilize the structure present in signals for improved recovery. In addition to the algorithm that considers just the sparsity structure of sparse signals, tools that target additional structure of the sparsity recovery problem are proposed. These include several algorithms for a) block-sparse signal estimation, b) joint reconstruction of several common support sparse signals, and c

  6. A Massive Structured Data Storage Technology for Commodity Screening Applications

    Directory of Open Access Journals (Sweden)

    Xu Feng

    2017-01-01

    Full Text Available With the rapid development of e-commerce, the number of goods has become more and more. When commodity screening system is used to store and process mass information, the existing models require all nodes in the distributed system to work in parallel, then the results of each node are integrated to get the final results, the process produces a lot of invalid queries. In order to solve this problem, proposed a new distributed structured data storage method. It statistics the history search results and chooses the high frequency or core columns to be key columns. The data can be stored based key columns and distribute system architecture. Then in the searching stage, only some nodes work when the search refer to key columns. The results show that this method can reduce the tasks and improve the throughout without extra storage consumption.

  7. Structural neuroimaging in neuropsychology: History and contemporary applications.

    Science.gov (United States)

    Bigler, Erin D

    2017-11-01

    Neuropsychology's origins began long before there were any in vivo methods to image the brain. That changed with the advent of computed tomography in the 1970s and magnetic resonance imaging in the early 1980s. Now computed tomography and magnetic resonance imaging are routinely a part of neuropsychological investigations with an increasing number of sophisticated methods for image analysis. This review examines the history of neuroimaging utilization in neuropsychological investigations, highlighting the basic methods that go into image quantification and the various metrics that can be derived. Neuroimaging methods and limitations for identify what constitutes a lesion are discussed. Likewise, the influence of various demographic and developmental factors that influence quantification of brain structure are reviewed. Neuroimaging is an integral part of 21st Century neuropsychology. The importance of neuroimaging to advancing neuropsychology is emphasized. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  8. Quantum Monte Carlo for electronic structure: Recent developments and applications

    International Nuclear Information System (INIS)

    Rodriguez, M.M.S.; Lawrence Berkeley Lab., CA

    1995-04-01

    Quantum Monte Carlo (QMC) methods have been found to give excellent results when applied to chemical systems. The main goal of the present work is to use QMC to perform electronic structure calculations. In QMC, a Monte Carlo simulation is used to solve the Schroedinger equation, taking advantage of its analogy to a classical diffusion process with branching. In the present work the author focuses on how to extend the usefulness of QMC to more meaningful molecular systems. This study is aimed at questions concerning polyatomic and large atomic number systems. The accuracy of the solution obtained is determined by the accuracy of the trial wave function's nodal structure. Efforts in the group have given great emphasis to finding optimized wave functions for the QMC calculations. Little work had been done by systematically looking at a family of systems to see how the best wave functions evolve with system size. In this work the author presents a study of trial wave functions for C, CH, C 2 H and C 2 H 2 . The goal is to study how to build wave functions for larger systems by accumulating knowledge from the wave functions of its fragments as well as gaining some knowledge on the usefulness of multi-reference wave functions. In a MC calculation of a heavy atom, for reasonable time steps most moves for core electrons are rejected. For this reason true equilibration is rarely achieved. A method proposed by Batrouni and Reynolds modifies the way the simulation is performed without altering the final steady-state solution. It introduces an acceleration matrix chosen so that all coordinates (i.e., of core and valence electrons) propagate at comparable speeds. A study of the results obtained using their proposed matrix suggests that it may not be the optimum choice. In this work the author has found that the desired mixing of coordinates between core and valence electrons is not achieved when using this matrix. A bibliography of 175 references is included

  9. Non-linear finite element analyses applicable for the design of large reinforced concrete structures

    NARCIS (Netherlands)

    Engen, M; Hendriks, M.A.N.; Øverli, Jan Arve; Åldstedt, Erik

    2017-01-01

    In order to make non-linear finite element analyses applicable during assessments of the ultimate load capacity or the structural reliability of large reinforced concrete structures, there is need for an efficient solution strategy with a low modelling uncertainty. A solution strategy comprises

  10. Application of partial differential equation modeling of the control/structural dynamics of flexible spacecraft

    Science.gov (United States)

    Taylor, Lawrence W., Jr.; Rajiyah, H.

    1991-01-01

    Partial differential equations for modeling the structural dynamics and control systems of flexible spacecraft are applied here in order to facilitate systems analysis and optimization of these spacecraft. Example applications are given, including the structural dynamics of SCOLE, the Solar Array Flight Experiment, the Mini-MAST truss, and the LACE satellite. The development of related software is briefly addressed.

  11. Giddens à la carte? Appraising empirical applications of structuration theory in management and organization studies

    NARCIS (Netherlands)

    den Hond, F.; Boersma, F.K.; Heres, L.; Kroes, E.H.J.; van Oirschot, E.

    2012-01-01

    There is an increasing interest in the application of Structuration Theory in the fields of management and organization studies. Based upon a thorough literature review, we have come up with a data-set to assess how Structuration Theory has been used in empirical research. We use three key concepts

  12. Application of a robust linear control design to a truss structure with nonlinear joints

    Science.gov (United States)

    Webster, Mark; Vander Velde, Wallace

    1991-01-01

    An efficient nonlinear equivalent beam finite-element method for the application of a full state feedback design is described, which is robust to plant uncertainties to a beamlike truss structure with nonlinear elements. The method may be extended to model nonlinear structures with other types of control systems, such as model-based compensators.

  13. CIME Summer Course on Exploiting Hidden Structure in Matrix Computations : Algorithms and Applications

    CERN Document Server

    Simoncini, Valeria

    2016-01-01

    Focusing on special matrices and matrices which are in some sense "near" to structured matrices, this volume covers a broad range of topics of current interest in numerical linear algebra. Exploitation of these less obvious structural properties can be of great importance in the design of efficient numerical methods, for example algorithms for matrices with low-rank block structure, matrices with decay, and structured tensor computations. Applications range from quantum chemistry to queuing theory. Structured matrices arise frequently in applications. Examples include banded and sparse matrices, Toeplitz-type matrices, and matrices with semi-separable or quasi-separable structure, as well as Hamiltonian and symplectic matrices. The associated literature is enormous, and many efficient algorithms have been developed for solving problems involving such matrices. The text arose from a C.I.M.E. course held in Cetraro (Italy) in June 2015 which aimed to present this fast growing field to young researchers, exploit...

  14. 14 CFR 1251.101 - Application.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Application. 1251.101 Section 1251.101 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION NONDISCRIMINATION ON BASIS OF HANDICAP General Provisions § 1251.101 Application. This part applies to each recipient of Federal financial...

  15. 14 CFR 1253.200 - Application.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Application. 1253.200 Section 1253.200 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Coverage § 1253.200 Application...

  16. Structure and applications of point form relativistic quantum mechanics

    International Nuclear Information System (INIS)

    Klink, W.H.

    2003-01-01

    The framework of point form relativistic quantum mechanics is used to construct mass and current operators for hadronic systems with finite degree of freedom. For the point form all of the interactions are in the four-momentum operator and, since Lorentz transformations are kinematic, the theory is manifestly covariant. In the Bakamjian-Thomas version of the point form the four-momentum operator is written as a product of the four-velocity operator and mass operator, where the mass operator is the sum of free and interacting mass operators. Interacting mass operators can be constructed from vertices, matrix elements of local field operators evaluated at the space-time point zero, where the states are eigenstates of the four-velocity. Applications include the study of the spectra and widths of vector mesons, viewed as bound states of quark-antiquark pairs. Besides mass operators, current operators are needed to compute form factors. Form factors are matrix elements of current operators on mass operator eigenstates and are often calculated with one-body current operators (in the point form this is called the point form spectator approximation); but in a properly relativistic theory there must also be many-body current operators. Minimal currents needed to satisfy current conservation in the presence of hadronic interactions (called dynamically determined currents) are shown to be easily calculated in the point form. (author)

  17. Application of manufacturing constraints to structural optimization of thin-walled structures

    Science.gov (United States)

    Kuczek, T.

    2016-02-01

    Topology optimization can be a very useful tool for creating conceptual designs for vehicles. Structures suggested by topology optimization often turn out to be difficult to implement in manufacturing processes. Presently, rail vehicle structures are made by welding sheet metal parts. This leads to many complications and increased weight of the vehicle. This article presents a new design concept for modern rail vehicle structures made of standardized, thin-walled, closed, steel profiles that fulfil the stress and manufacturing requirements. For this purpose, standard software for topology optimization was used with a new way of preprocessing the design space. The design methodology is illustrated by an example of the topology optimization of a freight railcar. It is shown that the methodology turns out to be a useful tool for obtaining optimal structure design that fulfils the assumed manufacturing constraints.

  18. An original architectured NiTi silicone rubber structure for biomedical applications

    OpenAIRE

    Rey, Thierry; Le Cam, Jean-Benoit; Chagnon, Grégory; Favier, Denis; Rebouah, Marie; Razan, Florence; Robin, Eric; Didier, Pierre; Heller, Ludek; Faure, S; Janouchova, K

    2014-01-01

    International audience; This paper deals with composite structures for biomedical applications. For this purpose, an architectured tubular structure composed of Nickel Titanium (NiTi) Shape Memory Alloy (SMA) and silicone rubber was fabricated. One of the main interest of such structures is to ensure a good adhesion between its two constitutive materials. A previous study of the authors (Rey et al., 2014) has shown that the adhesion between NiTi and silicone rubber can be improved by an adhes...

  19. APPLICATION OF AEM IN PROGRESSIVE COLLAPSE DYNAMICS ANALYSIS OF R.C. STRUCTURES

    OpenAIRE

    Osama El-Mahdy; El-Sayed El-Kasaby; Hala Abusafa; Amr El-Gamal

    2018-01-01

    The Finite Element Method (FEM) and the other numerical strategies are viably actualized in linear and non-linear analysis of structures. Recently, a new displacement based on Applied Element Method (AEM) has been developed. It is applicable for static and dynamic for both linear and non-linear analysis of framed and continuum structures. In AEM, the structural member is partitioned into virtual elements connected through normal and shear springs representing stresses and strains of certain p...

  20. Quantum Monte Carlo for electronic structure: Recent developments and applications

    Energy Technology Data Exchange (ETDEWEB)

    Rodriquez, Maria Milagos Soto [Lawrence Berkeley Lab. and Univ. of California, Berkeley, CA (United States). Dept. of Chemistry

    1995-04-01

    Quantum Monte Carlo (QMC) methods have been found to give excellent results when applied to chemical systems. The main goal of the present work is to use QMC to perform electronic structure calculations. In QMC, a Monte Carlo simulation is used to solve the Schroedinger equation, taking advantage of its analogy to a classical diffusion process with branching. In the present work the author focuses on how to extend the usefulness of QMC to more meaningful molecular systems. This study is aimed at questions concerning polyatomic and large atomic number systems. The accuracy of the solution obtained is determined by the accuracy of the trial wave function`s nodal structure. Efforts in the group have given great emphasis to finding optimized wave functions for the QMC calculations. Little work had been done by systematically looking at a family of systems to see how the best wave functions evolve with system size. In this work the author presents a study of trial wave functions for C, CH, C2H and C2H2. The goal is to study how to build wave functions for larger systems by accumulating knowledge from the wave functions of its fragments as well as gaining some knowledge on the usefulness of multi-reference wave functions. In a MC calculation of a heavy atom, for reasonable time steps most moves for core electrons are rejected. For this reason true equilibration is rarely achieved. A method proposed by Batrouni and Reynolds modifies the way the simulation is performed without altering the final steady-state solution. It introduces an acceleration matrix chosen so that all coordinates (i.e., of core and valence electrons) propagate at comparable speeds. A study of the results obtained using their proposed matrix suggests that it may not be the optimum choice. In this work the author has found that the desired mixing of coordinates between core and valence electrons is not achieved when using this matrix. A bibliography of 175 references is

  1. Crack path in aeronautical titanium alloy under ultrasonic torsion loading

    Directory of Open Access Journals (Sweden)

    A. Nikitin

    2016-01-01

    Full Text Available This paper discusses features of fatigue crack initiation and growth in aeronautical VT3-1 titanium alloy under pure torsion loading in gigacycle regime. Two materials: extruded and forged VT3-1 titanium alloys were studied. Torsion fatigue tests were performed up to fatigue life of 109 cycles. The results of the torsion tests were compared with previously obtained results under fully reversed axial loading on the same alloys. It has been shown that independently on production process as surface as well subsurface crack initiation may appear under ultrasonic torsion loading despite the maximum stress amplitude located at the specimen surface. In the case of surface crack initiation, a scenario of crack initiation and growth is similar to HCF regime except an additional possibility for internal crack branching. In the case of subsurface crack, the initiation site is located below the specimen surface (about 200 μm and is not clearly related to any material flaw. Internal crack initiation is produced by shear stress in maximum shear plane and early crack growth is in Mode II. Crack branching is limited in the case of internal crack initiation compared to surface one. A typical ‘fish-eye’ crack can be observed at the torsion fracture surface, but mechanism of crack initiation seems not to be the same than under axial fatigue loading.

  2. The aeronautics face-gear NC hobbing machining technology

    Science.gov (United States)

    Wu, Canhui; Wang, Yanzhong

    2013-03-01

    Face-gear drives become the main direction of research for aeronautical drives because of their special advantages. Face-gear machining problems have became to baffle the embedded research for face-gear. The basal coordinate systems of face-gear hobbing were setted up according to the face-gear hobbing theory. The hobbing surface equation of facegear was established by using the equation of pinion tooth surface and matrix for coordinate transform based on the gear geometry and applied theory, then the hobbing tooth surface constrain conditions for dedendum undercutting were analyzed, at the same time, the hobbing nodal points were used to construct the three-dimensional basal worm model of face-gear hob by recurring to the three-dimensional software. Furthermore, the special hob for face-gear machining was designed and manufactured. The exact assembly and machining simulation were finished by using the program development software VC++6.0 and the UG customization function in the light of the face-gear hobbing theory. It validates the hob correctness and gets the gear hobbing program. According to the result of machining simulation, facegear numerical control(NC) hob machining was realized in the four-axis NC machine tool. It improves the cutting efficiency and establishs the base for face-gear grinding.

  3. Ultra-Lightweight Nanocomposite Foams and Sandwich Structures for Space Structure Applications

    Science.gov (United States)

    Tan, Seng

    2012-01-01

    Microcellular nanocomposite foams and sandwich structures have been created to have excellent electrical conductivity and radiation-resistant properties using a new method that does not involve or release any toxicity. The nanocomposite structures have been scaled up in size to 12 X 12 in. (30 X 30 cm) for components fabrication. These sandwich materials were fabricated mainly from PE, CNF, and carbon fibers. Test results indicate that they have very good compression and compression-after-impact properties, excellent electrical conductivity, and superior space environment durability. Compression tests show that 1000 ESH (equivalent Sun hours) of UV exposure has no effect on the structural properties of the sandwich structures. The structures are considerably lighter than aluminum alloy (= 36 percent lighter), which translates to 36 percent weight savings of the electronic enclosure and its housing. The good mechanical properties of the materials may enable the electronic housing to be fabricated with a thinner structure that further reduces the weight. There was no difficulty in machining the sandwich specimens into electronic enclosure housing.

  4. Pore structure characteristics after two years biochar application to a sandy loam field

    DEFF Research Database (Denmark)

    Sun, Zhencai; Arthur, Emmanuel; de Jonge, Lis Wollesen

    2015-01-01

    Soil pore structure comprises the size and shape of soil pores and has a major impact on water retention and gas movement. The porous nature of biochar suggests that its application to soil can potentially alter soil pore structure characteristics, and the purpose of this study was to evaluate...... the effects of birch wood biochar (20, 40, and 100 Mg ha−1) applied to a sandy loam on soil total porosity and pore structure indices. Bulk and intact soil samples were collected for physicochemical analyses and water retention and gas diffusivity measurements between pF 1.0 and pF 3.0. Biochar application...... reduced bulk density and increased total porosity especially for soil with 100 Mg ha−1 biochar (16% and 14% reduction in bulk density and total porosity, respectively). Biochar application of more than 20 Mg ha−1 enhanced water retention, and the trend increased with increasing biochar application rate...

  5. Synthesis, crystal structure and applications of palladium thiosalicylate complexes

    Directory of Open Access Journals (Sweden)

    S.B. Moosun

    2017-05-01

    Full Text Available Three palladium thiosalicylate complexes [Pd(tb(bipy]·3H2O (1, [Pd2(tb2(bipy2]·(dtdb2 (2 and [Pd2(tb2(phen2]·dtdb·H2O (3 (bipy = bipyridine; phen = phenanthroline were prepared from the reaction of PdCl2(CH3CN2 with dithiosalicylic acid (dtdb which underwent cleavage to form thiobenzoate anion (tb in DMF/MeOH. Square planar geometries of the complexes with a N2SO coordination type were proposed on the basis of single crystal X-ray structural study. The presence of trapped and uncoordinated dtdb was observed in complexes 2 and 3. Complexes 1–3 were evaluated as catalysts for Heck coupling reactions of methyl acrylate with iodobenzene, and showed moderate activities at a very low catalyst loading. Complex 1 was found to inhibit the growth of bacteria and scavenge free radicals efficiently.

  6. Exploration and Development of High Entropy Alloys for Structural Applications

    Directory of Open Access Journals (Sweden)

    Daniel B. Miracle

    2014-01-01

    Full Text Available We develop a strategy to design and evaluate high-entropy alloys (HEAs for structural use in the transportation and energy industries. We give HEA goal properties for low (≤150 °C, medium (≤450 °C and high (≥1,100 °C use temperatures. A systematic design approach uses palettes of elements chosen to meet target properties of each HEA family and gives methods to build HEAs from these palettes. We show that intermetallic phases are consistent with HEA definitions, and the strategy developed here includes both single-phase, solid solution HEAs and HEAs with intentional addition of a 2nd phase for particulate hardening. A thermodynamic estimate of the effectiveness of configurational entropy to suppress or delay compound formation is given. A 3-stage approach is given to systematically screen and evaluate a vast number of HEAs by integrating high-throughput computations and experiments. CALPHAD methods are used to predict phase equilibria, and high-throughput experiments on materials libraries with controlled composition and microstructure gradients are suggested. Much of this evaluation can be done now, but key components (materials libraries with microstructure gradients and high-throughput tensile testing are currently missing. Suggestions for future HEA efforts are given.

  7. Introductory group theory and its application to molecular structure

    CERN Document Server

    Ferraro, John R

    1975-01-01

    The success of the first edition of this book has encouraged us to revise and update it. In the second edition we have attempted to further clarify por­ tions of the text in reference to point symmetry, keeping certain sections and removing others. The ever-expanding interest in solids necessitates some discussion on space symmetry. In this edition we have expanded the discus­ sion on point symmetry to include space symmetry. The selection rules in­ clude space group selection rules (for k = 0). Numerous examples are pro­ vided to acquaint the reader with the procedure necessary to accomplish this. Recent examples from the literature are given to illustrate the use of group theory in the interpretation of molecular spectra and in the determination of molecular structure. The text is intended for scientists and students with only a limited theoretical background in spectroscopy. For this reason we have presented detailed procedures for carrying out the selection rules and normal coor­ dinate treatment of ...

  8. Editorial Core-Shell Nano structures: Modeling, Fabrication, Properties, and Applications

    International Nuclear Information System (INIS)

    Qi, W.; Luo, L.; Qian, H.; Ouyang, G.; Nanda, K.K.; Obare, S.O.

    2012-01-01

    Core-shell nano structures, a family of nano materials, have attracted increasing research interest due to their unique structural features that consist of an inner core and an external shell of different chemical compositions. These structural features allow the possibility of combining distinctive properties of varied materials. Comparatively, core-shell nano structures have exhibited improved physical and chemical properties relative to their single-component counterparts. The inherent emergent chemical and physical properties of core-shell nano structures are of great importance to a potentially broader range of applications including electronics, magnetism, optics, and catalysis. So far a large number of core-shell nano structures have been successfully fabricated using approaches ranging from laser ablation and high-temperature evaporation to carbothermal reduction and hydrothermal methods. Structural characterization of these nano structures and determination of their unique properties for various applications have been well documented. This special issue is devoted to describing a number of unique properties and applications of core-shell nano structures by introducing a few research papers in this field.

  9. Unmanned aerial vehicle (UAV) application to the structural health assessment of large civil engineering structures

    Science.gov (United States)

    Castiglioni, Carlo A.; Rabuffetti, Angelo S.; Chiarelli, Gian P.; Brambilla, Giovanni; Georgi, Julia

    2017-09-01

    This paper summarizes the experience gained in the structural assessment of an existing Thermal Power Plant (TPP) located near Pristina, focusing on the cooling tower and the flue gas stack, which are the main structures of the TPP. Scope of the work was the evaluation of the actual conditions of the structures and to identify the eventual repair measures in order to guarantee a safe and reliable operation of the TPP in view of the extension of its operational lifetime for the next 30 years. With this aim, a sequence of different activities was performed, like: a topographic survey to compare the actual geometrical configuration with the design one, an investigation of the material properties, an in depth visual inspection in order to detect any visible existing damage. Due to the very high elevations of the constructions and to the lack of appropriate structures aimed to their inspections and maintenance, this activity could not be performed without using Unmanned Aerial Vehicle (UAV). This resulted the safest, most economical and less time-consuming solution identified to map the surface damage in the reinforced concrete elements of these large structures including zones that could not be inspected because out of reach by other means.

  10. Vorticity and turbulence effects in fluid structure interaction an application to hydraulic structure design

    CERN Document Server

    Brocchini, M

    2006-01-01

    This book contains a collection of 11 research and review papers devoted to the topic of fluid-structure interaction.The subject matter is divided into chapters covering a wide spectrum of recognized areas of research, such as: wall bounded turbulence; quasi 2-D turbulence; canopy turbulence; large eddy simulation; lake hydrodynamics; hydraulic hysteresis; liquid impacts; flow induced vibrations; sloshing flows; transient pipe flow and air entrainment in dropshaft.The purpose of each chapter is to summarize the main results obtained by the individual research unit through a year-long activity on a specific issue of the above list. The main feature of the book is to bring state of the art research on fluid structure interaction to the attention of the broad international community.This book is primarily aimed at fluid mechanics scientists, but it will also be of value to postgraduate students and practitioners in the field of fluid structure interaction.

  11. Thermal Characterization of Defects in Aircraft Structures Via Spatially Controlled Heat Application

    Science.gov (United States)

    Cramer, K. Elliott; Winfree, William P.

    1997-01-01

    Recent advances in thermal imaging technology have spawned a number of new thermal NDE techniques that provide quantitative information about flaws in aircraft structures. Thermography has a number of advantages as an inspection technique. It is a totally noncontacting, nondestructive, imaging technology capable of inspecting a large area in a matter of a few seconds. The development of fast, inexpensive image processors have aided in the attractiveness of thermography as an NDE technique. These image processors have increased the signal to noise ratio of thermography and facilitated significant advances in post-processing. The resulting digital images enable archival records for comparison with later inspections thus providing a means of monitoring the evolution of damage in a particular structure. The National Aeronautics and Space Administration's Langley Research Center has developed a thermal NDE technique designed to image a number of potential flaws in aircraft structures. The technique involves injecting a small, spatially controlled heat flux into the outer surface of an aircraft. Images of fatigue cracking, bond integrity and material loss due to corrosion are generated from measurements of the induced surface temperature variations. This paper will present a discussion of the development of the thermal imaging system as well as the techniques used to analyze the resulting thermal images. Spatial tailoring of the heat coupled with the analysis techniques represent a significant improvement in the delectability of flaws over conventional thermal imaging. Results of laboratory experiments on fabricated crack, disbond and material loss samples will be presented to demonstrate the capabilities of the technique. An integral part of the development of this technology is the use of analytic and computational modeling. The experimental results will be compared with these models to demonstrate the utility of such an approach.

  12. Lightweight Materials and Structures (LMS): Inflatable Structures

    Data.gov (United States)

    National Aeronautics and Space Administration —  Current inflatable structures are designed on the restraint layer’s short term properties with a Factor of Safety of 4 due to lack of long-term data on structural...

  13. Finite Element Analysis for Satellite Structures Applications to Their Design, Manufacture and Testing

    CERN Document Server

    Abdelal, Gasser F; Gad, Ahmed H

    2013-01-01

    Designing satellite structures poses an ongoing challenge as the interaction between analysis, experimental testing, and manufacturing phases is underdeveloped. Finite Element Analysis for Satellite Structures: Applications to Their Design, Manufacture and Testing explains the theoretical and practical knowledge needed to perform design of satellite structures. By layering detailed practical discussions with fully developed examples, Finite Element Analysis for Satellite Structures: Applications to Their Design, Manufacture and Testing provides the missing link between theory and implementation.   Computational examples cover all the major aspects of advanced analysis; including modal analysis, harmonic analysis, mechanical and thermal fatigue analysis using finite element method. Test cases are included to support explanations an a range of different manufacturing simulation techniques are described from riveting to shot peening to material cutting. Mechanical design of a satellites structures are covered...

  14. Application of Microgravity to the Assessment of Existing Structures and Structural Foundations.

    Science.gov (United States)

    1988-04-29

    UADGU Geophysique Francafse IUSRSU 6c. ADDRESS (City, State. and ZIP Code) 7b. ADDRESS (City, State, and ZIP Code) 20, Rue des Pavilions Box 65 92800...r (2.8 - 2.4) 286 AM~TCT f eldo f6 YOUOUVT 4. EXISTING STRUCTURES AND (U) CONPAGNIE DE PROSPECTION GEOPHYSIQUE FRANCAISE RUEIL-MALNAISO J LAKSHNRNRN

  15. Structural characterisations of AlN/diamond structures used for surface acoustic wave device applications

    OpenAIRE

    MORTET, Vincent; Elmazria, O; NESLADEK, Milos; Elhakiki, M; VANHOYLAND, Geert; D'HAEN, Jan; D'OLIESLAEGER, Marc; Alnot, P

    2003-01-01

    Diamond based surface acoustic wave (SAW) devices are extremely versatile devices that are just beginning to realize their commercial potential for use from sensors till high frequency (HF) filters for wireless telecommunications. One of the most promising piezoelectric materials for diamond based HF-SAW devices is aluminium nitride (AlN) thin film. The ability of AlN and diamond to be used for SAW applications depends both on the piezoelectric AlN layer properties and the diamond substrate p...

  16. Integrated Propulsion and Primary Structure Module for Small Satellite and CubeSat Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Over the last decade, the CubeSat platform has emerged as a viable alternative for both innovative technology development and scientific investigation. However, to...

  17. Integrated Propulsion and Primary Structure Module for Small Satellite and CubeSat Applications, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Over the last decade, the CubeSat platform has emerged as a viable alternative for both innovative technology development and scientific investigation. However, to...

  18. Structural Engineering of Metal-Mesh Structure Applicable for Transparent Electrodes Fabricated by Self-Formable Cracked Template

    Directory of Open Access Journals (Sweden)

    Yeong-gyu Kim

    2017-08-01

    Full Text Available Flexible and transparent conducting electrodes are essential for future electronic devices. In this study, we successfully fabricated a highly-interconnected metal-mesh structure (MMS using a self-formable cracked template. The template—fabricated from colloidal silica—can be easily formed and removed, presenting a simple and cost-effective way to construct a randomly and uniformly networked MMS. The structure of the MMS can be controlled by varying the spin-coating speed during the coating of the template solution or by stacking of metal-mesh layers. Through these techniques, the optical transparency and sheet resistance of the MMS can be designed for a specific purpose. A double-layered Al MMS showed high optical transparency (~80% in the visible region, low sheet resistance (~20 Ω/sq, and good flexibility under bending test compared with a single-layered MMS, because of its highly-interconnected wire structure. Additionally, we identified the applicability of the MMS in the case of practical devices by applying it to electrodes of thin-film transistors (TFTs. The TFTs with MMS electrodes showed comparable electrical characteristics to those with conventional film-type electrodes. The cracked template can be used for the fabrication of a mesh structure consisting of any material, so it can be used for not only transparent electrodes, but also various applications such as solar cells, sensors, etc.

  19. One-Dimensional SnO2 Nano structures: Synthesis and Applications

    International Nuclear Information System (INIS)

    Pan, J.; Shen, H.; Mathur, S.; Pan, J.

    2012-01-01

    Nano scale semiconducting materials such as quantum dots (0-dimensional) and one-dimensional (1D) structures, like nano wires, nano belts, and nano tubes, have gained tremendous attention within the past decade. Among the variety of 1D nano structures, tin oxide (SnO 2 ) semiconducting nano structures are particularly interesting because of their promising applications in optoelectronic and electronic devices due to both good conductivity and transparence in the visible region. This article provides a comprehensive review of the recent research activities that focus on the rational synthesis and unique applications of 1D SnO 2 nano structures and their optical and electrical properties. We begin with the rational design and synthesis of 1D SnO 2 nano structures, such as nano tubes, nano wires, nano belts, and some heterogeneous nano structures, and then highlight a range of applications (e.g., gas sensor, lithium-ion batteries, and nano photonics) associated with them. Finally, the review is concluded with some perspectives with respect to future research on 1D SnO 2 nano structures

  20. Nanocellulose as a sustainable biomass material: structure, properties, present status and future prospects in biomedical applications.

    Science.gov (United States)

    Xue, Yan; Mou, Zihao; Xiao, Huining

    2017-10-12

    Nanocellulose, extracted from the most abundant biomass material cellulose, has proved to be an environmentally friendly material with excellent mechanical performance owing to its unique nano-scaled structure, and has been used in a variety of applications as engineering and functional materials. The great biocompatibility and biodegradability, in particular, render nanocellulose promising in biomedical applications. In this review, the structure, treatment technology and properties of three different nanocellulose categories, i.e., nanofibrillated cellulose (NFC), nanocrystalline cellulose (NCC) and bacterial nanocellulose (BNC), are introduced and compared. The cytotoxicity, biocompatibility and frontier applications in biomedicine of the three nanocellulose categories were the focus and are detailed in each section. Future prospects concerning the cytotoxicity, applications and industrial production of nanocellulose are also discussed in the last section.