Sample records for aeropropulsion compact lightweight



    GONEN, Tahir


    Self compacting mortars have been used as repair mortar or to determine component rates of the self compacting concrete. In this study; self compacting lightweight mortars were produced with basaltic pumice and expanded perlite aggregate. Expanded perlite aggregate was used at rates 10, 20, 30, 40 and 50% by volume instead of pumice aggregate and compared with reference specimens made fully pumice aggregate. Self compacting lightweight mortars were compared with self compacting mortar with ri...

  2. A Compact, Light-weight, Reliable and Highly Efficient Heat Pump for Project (United States)

    National Aeronautics and Space Administration — RTI proposes to develop an efficient, reliable, compact and lightweight heat pump for space applications. The proposed effort is expected to lead to (at the end of...

  3. Compact and Lightweight Sabatier Reactor for Carbon Dioxide Reduction (United States)

    Junaedi, Christian; Hawley, Kyle; Walsh, Dennis; Roychoudhury, Subir; Abney, Morgan B.; Perry, Jay L.


    The utilization of CO2 to produce life support consumables, such as O2 and H2O, via the Sabatier reaction is an important aspect of NASA s cabin Atmosphere Revitalization System and In-Situ Resource Utilization architectures for both low-earth orbit and long-term manned space missions. In the current International Space Station (ISS) and other low orbit missions, metabolically-generated CO2 is removed from the cabin air and vented into space, resulting in a net loss of O2. This requires a continuous resupply of O2 via water electrolysis, and thus highlights the need for large water storage capacity. For long-duration space missions, the amount of life support consumables is limited and resupply options are practically nonexistent, thus atmosphere resource management and recycle becomes crucial to significantly reduce necessary O2 and H2O storage. Additionally, the potential use of the Martian CO2-rich atmosphere and Lunar regolith to generate life support consumables and propellant fuels is of interest to NASA. Precision Combustion, Inc. (PCI) has developed a compact, lightweight Microlith(Registered TradeMark)-based Sabatier (CO2 methanation) reactor which demonstrates the capability of achieving high CO2 conversion and near 100% CH4 selectivity at space velocities of 30,000-60,000 hr-1. The combination of the Microlith(Registered TradeMark) substrates and durable, novel catalyst coating permitted efficient Sabatier reactor operation that favors high reactant conversion, high selectivity, and long-term durability. This paper presents the reactor development and performance results at various operating conditions. Additionally, results from 100-hr durability tests and mechanical vibration tests are discussed.

  4. The effect of fly ash to self-compactability of pumice aggregate lightweight concrete

    Indian Academy of Sciences (India)

    Murat Kurt; Abdulkadir Cüneyt Aydin; Muhammed Said Gül; Rüstem Gül; Türkay Kotan


    This paper presents the results of an experimental study on the effects of fly ash, different water/(cement + mineral additive) ratios and pumice aggregates to some physical and mechanical properties of self-compacting lightweight aggregate concrete. In this study, pumice had been used as lightweight aggregates. Several properties of self-compacting pumice aggregate lightweight concretes like the unit weight, flow diameter, T50 time, flow diameter after an hour, V-funnel time, and L-box tests, 7, 28, 90 and 180-day compressive strength, 28-day splitting tensile strength, dry unit weight, water absorption, thermal conductivity and ultrasonic pulse velocity tests were investigated. For this purpose, 18 series of concrete samples were prepared in two groups. Pumice aggregate was used as a replacement of natural aggregate, at the levels of 0, 20, 40, 60, 80, and 100% by volume. Furthermore, a second series of 100% pumice aggregate was used for the production of self-compacting lightweight aggregate concrete with constant w/(c+m) ratios as 0.35, 0.40, and 0.45 by weight. The flow diameters, T50 times, paste volumes, 28-day compressive strengths, dry unit weights and thermal conductivities of self-compacting lightweight aggregate concrete were obtained in the range of 600–800 mm, 2–8 s, 471–572 lt/m3, 9.2–53.26 MPa, 839–2156 kg/m3 and 0.321–1.508 W/mk, respectively, which satisfies not only the strength requirement of semi-structural lightweight concrete but also the flowing ability requirements and thermal conductivity requirements of self-compacting lightweight aggregate concrete.

  5. The effect of blast furnace slag on the self-compactability of pumice aggregate lightweight concrete

    Indian Academy of Sciences (India)

    Murat Kurt; Türkay Kotan; Muhammed Said Gül; Rüstem Gül; Abdulkadir Cüneyt Aydin


    This paper presents the results of an experimental study of the effects of blast furnace slag, different water/(cement+mineral additive) ratios and pumice aggregates on some physical and mechanical properties of self-compacting lightweight aggregate concrete. In this study, pumice was used as lightweight aggregate. Several properties of self-compacting pumice aggregate lightweight concretes, such as unit weight, flow diameter, T50 time, flow diameter after an hour, V-funnel time, and L-box tests, 7, 28, 90 and 180-day compressive strength, 28-day splitting tensile strength, dry unit weight, water absorption, thermal conductivity and ultrasonic pulse velocity tests, were conducted. For this purpose, 18 series of concrete samples were prepared in two groups. In the first group, pumice aggregate at 100% replacement of natural aggregate was used in the production of self-compacting lightweight aggregate concrete with constant w/(c+m) ratios as 0.35, 0.40, and 0.45 by weight. Furthermore, as a second group, pumice aggregate was used as a replacement of natural aggregate, at the levels of 0, 20, 40, 60, 80, and 100% by volume. Flow diameters, T50 times, paste volumes, 28-day compressive strengths, dry unit weights, thermal conductivities and ultrasonic pulse velocity of self-compacting lightweight aggregate concrete were obtained over the range of 600–770 mm, 3–9 s, 435–540 l/m3, 10.6–65.0 MPa, 845–2278 kg/m3, 0.363–1.694 W/mK and 2617–4770 m/s respectively, which satisfies not only the strength requirement of semistructural lightweight concrete but also the flowing ability requirements and thermal conductivity requirements of self-compacting lightweight aggregate concrete.

  6. Lightweight self-compacting concrete reinforced with fibres for slab rehabilitation; Hormigon ligero autocompactante con fibras para rehabilitacion de forjados

    Energy Technology Data Exchange (ETDEWEB)

    Klein, N. S.; Fuente, A. de la; Aguado, A.; Maso, D.


    The slabs of some buildings in Barcelona are formed by unidirectional beams, with a ceramic arch in between, which are filled with broken pottery or construction waste. These structures often present problems such as displacement of the tiles arranged over it due to the lack of stiffness of the filling material. This supposes a risk to the user and could also cause durability problems. In order to rehabilitate it, a lightweight self-compacting concrete reinforced with fibres (HLACF) has been designed to be used as a filling material, improving the stiffness of the structure. This paper presents a structural analysis of a standard case and the results of an experimental campaign. The concrete showed a density of 1665 kg/m3, a slump flow of 605 mm and a compressive strength of 22.3 MPa, at 28 days. These results are in agreement with the requirements, overcoming common lightweight concrete segregation problems. (Author) 24 refs.

  7. Impact and promise of NASA aeropropulsion technology (United States)

    Saunders, Neal T.; Bowditch, David N.


    The aeropropulsion industry in the U.S. has established an enviable record of leading the world in aeropropulsion for commercial and military aircraft. NASA's aeropropulsion program (primarily conducted through the Lewis Research Center) has significantly contributed to that success through research and technology advances and technology demonstration. Some past NASA contributions to engines in current aircraft are reviewed, and technologies emerging from current research programs for the aircraft of the 1990's are described. Finally, current program thrusts toward improving propulsion systems in the 2000's for subsonic commercial aircraft and higher speed aircraft such as the High-Speed Civil Transport and the National Aerospace Plane are discussed.

  8. Experimental Investigation of the Effect of Manufactured Sand and Lightweight Sand on the Properties of Fresh and Hardened Self-Compacting Lightweight Concretes

    Directory of Open Access Journals (Sweden)

    Yiyun Zhu


    Full Text Available Self-compacting lightweight concrete (SCLC is a promising construction material for building applications, but most SCLCs today are made with river sand (RS. There is an increasing demand for environmental protection, as well as materials with a high strength/density ratio. The manufactured sand (MS and lightweight sand (LS as fine aggregates in cement-based composite materials have been receiving more attention among researchers. However, there is not much information about the effects of MS and LS on the properties of the fresh and hardened SCLCs. In this paper, the properties of fresh and hardened SCLC made with MS and LS were investigated by a series of experiments. SCLCs made with RS served as the control in this study. The test results show that increasing the sand ratio (from 0.40–0.50 decreased the filling ability and led to an increased T50 time, which is the time spent for the concrete to reach the 500 mm spread circle, for all of the fresh SCLCs. Although the passing ability of MS-SCLCs and LS-SCLCs is not as good as RS-SCLCs, their results are still within an acceptable range. The ratio of mechanical properties to density was found to increase with an increase of the sand ratio for all of the hardened SCLCs. MS-SCLCs presented the highest compressive strength among all of the SCLCs studied. Although the mean compressive strength of LS-SCLCs is lower than those of the other two SCLCs by 8%, their strength to density ratio is higher than others by 15%, and the ratio increases remarkably with the increase of the sand ratio. Permeability test results showed that the permeability coefficient of MS-SCLC is remarkably lower than that of LS-SCLC, but slightly higher than that of RS-SCLC.

  9. Microminiature rotary Stirling cryocooler for compact, lightweight, and low-power thermal imaging systems (United States)

    Filis, Avishai; Bar Haim, Zvi; Pundak, Nachman; Broyde, Ramon


    Novel compact and low power consuming cooled infrared thermal imagers as used in gyro-stabilized payloads of miniature unmanned aerial vehicles, Thermal small arms sights and tactical night vision goggles often rely on integral rotary micro-miniature closed cycle Stirling cryogenic engines. Development of EPI Antimonides technology and optimization of MCT technology allowed decreasing in order of magnitudes the level of dark current in infrared detectors thus enabling an increase in the optimal focal plane temperature in excess of 95K while keeping the same radiometric performances as achieved at 77K using regular technologies. Maintaining focal plane temperature in the range of 95K to 110K instead of 77K improves the efficiency of Stirling thermodynamic cycle thus enlarging cooling power and enabling the development of a mini micro cooler similar to RICOR's K562S model which is three times smaller, lighter and more compact than a standard tactical cryocooler like RICOR's K508 model. This cooler also features a new type of ball bearings and internal components which were optimized to fit tight bulk constraints and maintain the required life span, while keeping a low level of vibration and noise signature. Further, the functions of management the brushless DC motor and temperature stabilization are delivered by the newly developed high performance sensorless digital controller. By reducing Dewar Detector thermal losses and increasing the focal plane temperature, longer life time operation is expected as was proved with RICOR's K508 model. Resulting from this development, the RICOR K562S model cryogenic engine consumes 1.2 - 3.0 WDC while operating in the closed loop mode and maintaining the typical focal plane arrays at 200-100K. This makes it compatible with very compact battery packages allowing further reduction of the overall thermal imager weight thus making it comparable with the compatible uncooled infrared thermal imager relying on a microbolometer detector

  10. A compact, efficient, and lightweight laser head for CARLO®: integration, performance, and benefits (United States)

    Deibel, Waldemar; Schneider, Adrian; Augello, Marcello; Bruno, Alfredo E.; Juergens, Philipp; Cattin, Philippe


    Ever since the first functional lasers were built about 50 years ago, researchers and doctors dream of a medical use for such systems. Today's technology is finally advanced enough to realize these ambitions in a variety of medical fields. There are well-established laser based systems in ophthalmology, dental applications, treatment of kidney stones, and many more. Using lasers presents more than just an alternative to conventional methods for osteotomies. It offers less tissue damage, faster healing times, comparable intervention duration and in consequence improves postoperative treatment of patients. However, there are a few factors that limit routine applications. These technical drawbacks include missing depth control and safe guiding of the laser beam. This paper presents the engineering and integration of a miniaturized laser head for a computer assisted and robot-guided laser osteotome (CARLO®), which can overcome the mentioned drawbacks. The CARLO® device ensures a safe and precise guidance of the laser beam. Such guidance also enables new opportunities and methods, e.g. free geometrical functional cuts, which have the potential to revolutionize bone surgery. The laser head is optimized for beam shaping, target conditioning, working distance, compactness and the integration of all other parts needed, e.g. CCD-cameras for monitoring and referencing, a visible laser for cut simulation, etc. The beam coming out of the laser system is conditioned in shape, energy properties and working distance with an optical arrangement to achieve the desired cutting performance. Here also parameters like optical losses, operating mode, optics materials and long-term stability have are taken into account.

  11. Evaluation of the Strength Variation of Normal and Lightweight Self-Compacting Concrete in Full Scale Walls

    DEFF Research Database (Denmark)

    Hosseinali, M.; Ranjbar, M. M.; Rezvani, S. M.


    The strength of cast concrete along the height and length of large structural members might vary due to inadequate compaction, segregation, bleeding, head pressure, and material type. The distribution of strength within a series of full scale reinforced concrete walls was examined using non...... strength variation and the relationship to the strength of standard cube samples. Investigation of the strength variation along the height of the wall showed that SCC mixes had better strength uniformity and that the NC mix had the greatest strength variation. There were no significant strength differences...... between mixtures along the length of the walls. Furthermore, different admixture replacements did not have a meaningful effect on the strength distribution....

  12. Trends in aeropropulsion research and their impact on engineering education (United States)

    Povinelli, Louis A.; Reichert, Bruce A.; Glassman, Arthur J.


    This presentation is concerned with the trends in aeropropulsion both in the U.S. and abroad and the impact of these trends on the educational process in our universities. In this paper, we shall outline the new directions for research which may be of interest to educators in the aeropropulsion field. Awareness of new emphases, such as emission reductions, noise control, maneuverability, speed, etc., will have a great impact on engineering educators responsible for restructuring courses in propulsion. The information presented herein will also provide some background material for possible consideration in the future development of propulsion courses. In describing aeropropulsion, we are concerned primarily with air-breathing propulsion; however many observations apply equally as well to rocket engine systems. Aeropropulsion research needs are primarily motivated by technologies required for advanced vehicle systems and frequently driven by external requirements such as economic competitiveness, environmental concern and national security. In this presentation, vehicle based research is first described, followed by a discussion of discipline and multidiscipline research necessary to implement the vehicle-focused programs. The importance of collaboration in research and the training of future researchers concludes this presentation.

  13. A new calibration system for lightweight, compact and mobile Cavity-Enhanced Differential Optical Absorption Spectroscopy instruments (United States)

    Zielcke, Johannes; Horbanski, Martin; Pöhler, Denis; Frieß, Udo; Platt, Ulrich


    Absorption Spectroscopy has been employed for several decades now to study the earth's atmosphere. While the focus has been on remote sensing for a long time, lately there has been a renewed interest in in-situ methods, as point measurements allow an easier interpretation for highly inhomogeneous distributions of gases of interest compared to the integration approach of most remote sensing methods. One comparatively new method offering both advantages of in-situ measurements as well as being contactless is open-path Cavity-Enhanced Differential Optical Absorption Spectroscopy (CE-DOAS). Broadband open-path CE-DOAS instruments have been used for ten years now, and in the meantime allow the measurement of numerous atmospheric trace gases (e.g. NO2, NO3, IO, CHOCHO, HCHO). While those instruments were bulky and not very mobile at first, recent developments resulted in relatively lightweight (< 30 kg) instruments with a relatively low power consumption allowing mobile open-path measurements at remote field locations. An important operational issue has been the path length calibration in the field, necessary for the determination of the concentration of measured gases. Until now, often calibration gases were used with different scattering properties than air or known concentrations. However this methods has several major shortcomings, being rather inconvenient and cumbersome in the field with the need for compressed gas cylinders, as well as time consuming, preventing a quick check of the state of the instrument in the field after changing measurement locations. Here we present a new wavelength-resolved method for broadband CE-DOAS path length calibration. A small, custom made ring-down system is employed with a pulsed LED as light source. The wavelength is then resolved by tilting a narrow band interference filter. The system not only allows quick, automated path length calibrations without physical interaction on the instrument, but also saves weight, space and the

  14. Challenging the Future - Journey to Excellence. Aeropropulsion strategic plan for the 1990's (United States)

    Over the past several months, the Lewis Aeropropulsion Management Council (AMC) has conducted a critical assessment of its strategic plan. This assessment clearly indicated a need for change, both in the aeropropulsion program emphasis and in the approach to carrying out that program. Customers sent a strong message that the program must improve the timeliness of research and technology products and services and must work more closely with them to develop and transfer new technology. The strategic plan defines AMC's vision for the future and underlying organizational values. It contains a set of broad strategies and actions that point the way toward achieving the goals of customer satisfaction, organizational effectiveness, and programmatic excellence. Those strategies are expected to form the basis for the development of specific tactical plans by Lewis aeropropulsion thrust teams, divisions, and branches. To guide tactical planning of the aeropropulsion program, this strategic plan outlines the agency's strategic directions and long-range aeronautics goals, the aeropropulsion goals and key objectives for achieving them, projections of Lewis aeropropulsion budgets, planned allocations of resources, and the processes that will be used to measure success in carrying out the strategic plan.

  15. 70 Years of Aeropropulsion Research at NASA Glenn Research Center (United States)

    Reddy, Dhanireddy R.


    This paper presents a brief overview of air-breathing propulsion research conducted at the NASA Glenn Research Center (GRC) over the past 70 years. It includes a historical perspective of the center and its various stages of propulsion research in response to the countrys different periods of crises and growth opportunities. GRCs research and technology development covered a broad spectrum, from a short-term focus on improving the energy efficiency of aircraft engines to advancing the frontier technologies of high-speed aviation in the supersonic and hypersonic speed regimes. This paper highlights major research programs, showing their impact on industry and aircraft propulsion, and briefly discusses current research programs and future aeropropulsion technology trends in related areas

  16. Lightweight Structures. (United States)

    Shaver and Co., Michigan City, IN.

    One of the newest and most promising developments in architecture has been the use of lightweight structures for encapsulating space. Using this new technology, builders can enclose large and small areas at a fraction of the cost of conventional construction and at the same time provide interior space that is totally flexible. This brochure shows…

  17. Commercial Modular Aero-Propulsion System Simulation 40k (United States)

    Guo, Ten-Huei; Lavelle, Thomas; Litt, Jonathan; Csank, Jeffrey; May, Ryan


    The Commercial Modular Aero-Propulsion System Simulation 40k (CMAPSS40k) software package is a nonlinear dynamic simulation of a 40,000-pound (approximately equals 178-kN) thrust class commercial turbofan engine, written in the MATLAB/Simulink environment. The model has been tuned to capture the behavior of flight test data, and is capable of running at any point in the flight envelope [up to 40,000 ft (approximately equals 12,200 m) and Mach 0.8]. In addition to the open-loop engine, the simulation includes a controller whose architecture is representative of that found in industry. C-MAPSS40k fills the need for an easy-to-use, realistic, transient simulation of a medium-size commercial turbofan engine with a representative controller. It is a detailed component level model (CLM) written in the industry-standard graphical MATLAB/Simulink environment to allow for easy modification and portability. At the time of this reporting, no other such model exists in the public domain.

  18. Revolutionary Aeropropulsion Concept for Sustainable Aviation: Turboelectric Distributed Propulsion (United States)

    Kim, Hyun Dae; Felder, James L.; Tong, Michael. T.; Armstrong, Michael


    In response to growing aviation demands and concerns about the environment and energy usage, a team at NASA proposed and examined a revolutionary aeropropulsion concept, a turboelectric distributed propulsion system, which employs multiple electric motor-driven propulsors that are distributed on a large transport vehicle. The power to drive these electric propulsors is generated by separately located gas-turbine-driven electric generators on the airframe. This arrangement enables the use of many small-distributed propulsors, allowing a very high effective bypass ratio, while retaining the superior efficiency of large core engines, which are physically separated but connected to the propulsors through electric power lines. Because of the physical separation of propulsors from power generating devices, a new class of vehicles with unprecedented performance employing such revolutionary propulsion system is possible in vehicle design. One such vehicle currently being investigated by NASA is called the "N3-X" that uses a hybrid-wing-body for an airframe and superconducting generators, motors, and transmission lines for its propulsion system. On the N3-X these new degrees of design freedom are used (1) to place two large turboshaft engines driving generators in freestream conditions to minimize total pressure losses and (2) to embed a broad continuous array of 14 motor-driven fans on the upper surface of the aircraft near the trailing edge of the hybrid-wing-body airframe to maximize propulsive efficiency by ingesting thick airframe boundary layer flow. Through a system analysis in engine cycle and weight estimation, it was determined that the N3-X would be able to achieve a reduction of 70% or 72% (depending on the cooling system) in energy usage relative to the reference aircraft, a Boeing 777-200LR. Since the high-power electric system is used in its propulsion system, a study of the electric power distribution system was performed to identify critical dynamic and

  19. Lightweight Phase-Change Material For Solar Power (United States)

    Stark, Philip


    Lightweight panels containing phase-change materials developed for use as heat-storage elements of compact, lightweight, advanced solar dynamic power system. During high insolation, heat stored in panels via latent heat of fusion of phase-change material; during low insolation, heat withdrawn from panels. Storage elements consist mainly of porous carbon-fiber structures imbued with germanium. Developed for use aboard space station in orbit around Earth, also adapted to lightweight, compact, portable solar-power systems for use on Earth.

  20. On the automobile lightweight

    Institute of Scientific and Technical Information of China (English)

    Ma Mingtu; Yi Hongliang; Lu Hongzhou; Wan Xinming


    The significance, description parameters, evaluation method, implement way and design for lightweight of au- tomobile are comprehensively reviewed. The relationship among the performances of auto parts & components, the prop- erties of materials and application of advanced technologies is also elaborated. According to recently related progress of lightweight and authors' research and developing work, lightweight of automobile is comprehensively and systematically overviewed.

  1. Compact, Lightweight, High Voltage Propellant Isolators Project (United States)

    National Aeronautics and Space Administration — TA&T, Inc. proposes an enabling fabrication process for high voltage isolators required in high power solar electric and nuclear electric propulsion (SEP and...

  2. Compact, Lightweight Isolation Platform (CLIP) Project (United States)

    National Aeronautics and Space Administration — NASA has a critical need for improved bi-directional data transmission rates from a variety of spacecraft to Earth. NASA estimates that the current Mars to Earth...

  3. Aerosciences, Aero-Propulsion and Flight Mechanics Technology Development for NASA's Next Generation Launch Technology Program (United States)

    Cockrell, Charles E., Jr.


    The Next Generation Launch Technology (NGLT) program, Vehicle Systems Research and Technology (VSR&T) project is pursuing technology advancements in aerothermodynamics, aeropropulsion and flight mechanics to enable development of future reusable launch vehicle (RLV) systems. The current design trade space includes rocket-propelled, hypersonic airbreathing and hybrid systems in two-stage and single-stage configurations. Aerothermodynamics technologies include experimental and computational databases to evaluate stage separation of two-stage vehicles as well as computational and trajectory simulation tools for this problem. Additionally, advancements in high-fidelity computational tools and measurement techniques are being pursued along with the study of flow physics phenomena, such as boundary-layer transition. Aero-propulsion technology development includes scramjet flowpath development and integration, with a current emphasis on hypervelocity (Mach 10 and above) operation, as well as the study of aero-propulsive interactions and the impact on overall vehicle performance. Flight mechanics technology development is focused on advanced guidance, navigation and control (GN&C) algorithms and adaptive flight control systems for both rocket-propelled and airbreathing vehicles.

  4. Compact rotating cup anemometer (United States)

    Wellman, J. B.


    Compact, collapsible rotating cup anemometer is used in remote locations where portability and durability are factors in the choice of equipment. This lightweight instrument has a low wind-velocity threshold, is capable of withstanding large mechanical shocks while in its stowed configuration, and has fast response to wind fluctuations.

  5. Compact Fiber Lasers for Coherent LIDAR Project (United States)

    National Aeronautics and Space Administration — This is a proposal to investigate the feasibility of developing a low cost, compact, lightweight, high power (>500m W) and narrow linewidth 1.5 and 1.06 micron...

  6. LUCA:Lightweight Ubiquitous Computing Architecture

    Institute of Scientific and Technical Information of China (English)

    SUN Dao-qing; CAO Qi-ying


    Lightweight ubiquitous computing security architecture was presented. Lots of our recent researches have been integrated in this architecture. And the main current researches in the related area have also been absorbed. The main attention of this paper was providing a compact and realizable method to apply ubiquitous computing into our daily lives under sufficient secure guarantee. At last, the personal intelligent assistant system was presented to show that this architecture was a suitable and realizable security mechanism in solving the ubiquitous computing problems.


    Energy Technology Data Exchange (ETDEWEB)

    Fred Sabins


    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems, including foamed and sodium silicate slurries. During this project quarter, a comparison study of the three cement systems examined the effect that cement drillout has on the three cement systems. Testing to determine the effect of pressure cycling on the shear bond properties of the cement systems was also conducted. This report discusses testing that was performed to analyze the alkali-silica reactivity of ULHS in cement slurries.

  8. Lightweight Robotic Excavation Project (United States)

    National Aeronautics and Space Administration — Lightweight robotic excavators address the need for machines that dig, collect, transport and dump lunar soil. Robust and productive small robots enable mining rich...

  9. Lightweight Robotic Excavation Project (United States)

    National Aeronautics and Space Administration — Robust, lightweight, power-efficient excavation robots are mission enablers for lunar outposts and surface systems. Lunar excavators of this type cost-effectively...

  10. Lightweight Metal Mirrors (United States)

    Gossett, E.; Winslow, P.


    Two "eggcrate" halves brazed together. Lightweight flat mirrors fabricated by machining pockets in two plates of beryllium and brazing machined halves together. Mirror less than half weight of same mirror made by previous design.

  11. Manufacturing of Lightweight Mirror

    Institute of Scientific and Technical Information of China (English)


    Fabrication of the lightweight mirror is one of the key techniques for many large optical systems. CAD,CAM and CNC technologies are adopted in designing and manufacturing such mirrors in CIOMP. Better working efficiency and higher lightweight grade have been achieved. The results show that mirrors up to 70% weight reduction and 0.02λ(rms.) surface accuracy or better can be obtained.


    Energy Technology Data Exchange (ETDEWEB)

    Fred Sabins


    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses tasks performed in the fourth quarter as well as the other three quarters of the past year. The subjects that were covered in previous reports and that are also discussed in this report include: Analysis of field laboratory data of active cement applications from three oil-well service companies; Preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; Summary of pertinent information from Russian ultra-lightweight cement literature review; and Comparison of compressive strengths of ULHS systems using ultrasonic and crush methods Results reported from the fourth quarter include laboratory testing of ULHS systems along with other lightweight cement systems--foamed and sodium silicate slurries. These comparison studies were completed for two different densities (10.0 and 11.5 lb/gal) and three different field application scenarios. Additional testing included the mechanical properties of ULHS systems and other lightweight systems. Studies were also performed to examine the effect that circulation by centrifugal pump during mixing has on breakage of ULHS.

  13. Lightweight and Compace Multifunction Computer-Controlled Strength and Aerobic Training Device Project (United States)

    National Aeronautics and Space Administration — TDA Research proposes to develop a computer-controlled lightweight and compact device for aerobic and resistive training (DART) to counteract muscular atrophy and...


    Energy Technology Data Exchange (ETDEWEB)

    Fred Sabins


    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems: foamed and sodium silicate slurries. Comparison studies of the three cement systems examined several properties: tensile strength, Young's modulus, water permeability, and shear bond. Testing was also done to determine the effect that temperature cycling has on the shear bond properties of the cement systems. In addition, analysis was carried out to examine alkali silica reactivity of slurries containing ULHS. Data is also presented from a study investigating the effects of mixing and pump circulation on breakage of ULHS. Information is also presented about the field application of ULHS in cementing a 7-in. intermediate casing in south Texas.

  15. Lightweight Electric Power Cable. (United States)


    8I~ .4 111 162 MICROCi Pi RL’ LUHION TESI CHARI "LIGHTWEIGHT ELECTRIC POWER CABLE" FINAL TECHNICAL REPORT SEPTEMBER 30, 1981 to SEPTEMBER 30, 1982... Vulcanized by heat to crosslink. TPE (Thermoplastic Elastomer) - Polymers having elastomeric proper- ties. Used as thermoplastics - melt formed by

  16. Lightweight Composite Intertank Structure (United States)

    Mehle, Greg V.


    Report presents results of study for proposed lightweight composite material alternative to present semimonocoque aluminum intertank structure for advanced launch vehicles. Proposed structure integrated assembly of sandwich panels made of laminated epoxy-matrix/carbon-fiber skins, and aluminum honeycomb core.

  17. Compact, Efficient, and Reliable Ventilation Fan for EVA Suits Project (United States)

    National Aeronautics and Space Administration — Advanced EVA suits for space exploration will need a portable life support system (PLSS) that is compact, lightweight, and highly reliable. A key component is a...

  18. Compact, Efficient, and Reliable Ventilation Fan for EVA Suits Project (United States)

    National Aeronautics and Space Administration — Advanced EVA suits for space exploration will need a portable life support system (PLSS) that is compact, lightweight, highly reliable, and meets stringent...

  19. Thin, Lightweight Solar Cell (United States)

    Brandhorst, Henry W., Jr.; Weinberg, Irving


    Improved design for thin, lightweight solar photovoltaic cells with front contacts reduces degradation of electrical output under exposure to energetic charged particles (protons and electrons). Increases ability of cells to maintain structural integrity under exposure to ultraviolet radiation by eliminating ultraviolet-degradable adhesives used to retain cover glasses. Interdigitated front contacts and front junctions formed on semiconductor substrate. Mating contacts formed on back surface of cover glass. Cover glass and substrate electrostatically bonded together.

  20. Lightweight bipolar storage battery (United States)

    Rowlette, John J. (Inventor)


    An apparatus [10] is disclosed for a lightweight bipolar battery of the end-plate cell stack design. Current flow through a bipolar cell stack [12] is collected by a pair of copper end-plates [16a,16b] and transferred edgewise out of the battery by a pair of lightweight, low resistance copper terminals [28a,28b]. The copper terminals parallel the surface of a corresponding copper end-plate [16a,16b] to maximize battery throughput. The bipolar cell stack [12], copper end-plates [16a,16b] and copper terminals [28a,28b] are rigidly sandwiched between a pair of nonconductive rigid end-plates [20] having a lightweight fiber honeycomb core which eliminates distortion of individual plates within the bipolar cell stack due to internal pressures. Insulating foam [30] is injected into the fiber honeycomb core to reduce heat transfer into and out of the bipolar cell stack and to maintain uniform cell performance. A sealed battery enclosure [ 22] exposes a pair of terminal ends [26a,26b] for connection with an external circuit.

  1. Lightweight, Self-Deploying Foam Antenna Structures (United States)

    Sokolowski, Witold; Levin, Steven; Rand, Peter


    Lightweight, deployable antennas for a variety of outer-space and terrestrial applications would be designed and fabricated according to the concept of cold hibernated elastic memory (CHEM) structures, according to a proposal. Mechanically deployable antennas now in use are heavy, complex, and unreliable, and they utilize packaging volume inefficiently. The proposed CHEM antenna structures would be simple and would deploy themselves without need for any mechanisms and, therefore, would be more reliable. The proposed CHEM antenna structures would also weigh less, could be packaged in smaller volumes, and would cost less, relative to mechanically deployable antennas. The CHEM concept was described in two prior NASA Tech Briefs articles: "Cold Hibernated Elastic Memory (CHEM) Expandable Structures" (NPO-20394), Vol. 23, No. 2 (February 1999), page 56; and "Solar Heating for Deployment of Foam Structures" (NPO-20961), Vol. 25, No. 10 (October 2001), page 36. To recapitulate from the cited prior articles: The CHEM concept is one of utilizing opencell foams of shape-memory polymers (SMPs) to make lightweight, reliable, simple, and inexpensive structures that can be alternately (1) compressed and stowed compactly or (2) expanded, then rigidified for use. A CHEM structure is fabricated at full size from a block of SMP foam in its glassy state [at a temperature below the glass-transition temperature (Tg) of the SMP]. The structure is heated to the rubbery state of the SMP (that is, to a temperature above Tg) and compacted to a small volume. After compaction, the structure is cooled to the glassy state of the SMP. The compacting force can then be released and the structure remains compact as long as the temperature is kept below Tg. Upon subsequent heating of the structure above Tg, the simultaneous elastic recovery of the foam and its shape-memory effect cause the structure to expand to its original size and shape. Once thus deployed, the structure can be rigidified by

  2. Lightweight enterprise architectures

    CERN Document Server

    Theuerkorn, Fenix


    STATE OF ARCHITECTUREArchitectural ChaosRelation of Technology and Architecture The Many Faces of Architecture The Scope of Enterprise Architecture The Need for Enterprise ArchitectureThe History of Architecture The Current Environment Standardization Barriers The Need for Lightweight Architecture in the EnterpriseThe Cost of TechnologyThe Benefits of Enterprise Architecture The Domains of Architecture The Gap between Business and ITWhere Does LEA Fit? LEA's FrameworkFrameworks, Methodologies, and Approaches The Framework of LEATypes of Methodologies Types of ApproachesActual System Environmen


    Directory of Open Access Journals (Sweden)

    NETESA M. I.


    Full Text Available Raising of problem. Concrete advisable to obtain a low strength with local secondary resources for recycling and reduce the environmental burden on the environment. But it is important to design such concrete compositions with a reduced flow of cement. It is known that the coefficient of efficiency of use of cement in the concrete of the heavy and B10 is less than about 0.5, which is almost two times smaller than in class B15 concrete and above. Even lower coefficient of efficiency in light concrete cement low strength. Therefore, it is important to find patterns determining the composition of lightweight concrete based on local-products industry with more efficient use of cement in them. Purpose.. Based on the analysis of earlier research results, including with the use of methods of mathematical planning of experiments to determine the concrete contents, which can provide the requirements for the underlying layers of the floor, the compressive strength of which should correspond to the class B5. It is important to provide the required strength at minimum flow of the cement, which is the most expensive and energy-intensive part of concrete. Conclusion. Analysis of the test results of control samples of concrete in 28-day-old, the following laws. The required tensile strength of concrete compressive strength of 7.0 MPa can be obtained in the test range when used in formulations as a filler as the Dnieper hydroelectric power station fly ash and tailings Krivoy Rog iron ore YuGOK. To ensure providing the required characteristic strength of the concrete in the underlying layers of the floor is advisable to use a nominal composition per cubic meter of concrete: cement 160 kg granshlaka Plant named after Petrovsky, 675 kg of fly ash Dnieper HPP 390 kg, 400 kg of sand, 230 liters of water. Thus, while ensuring rational grain composition components can obtain the desired strength lightweight concrete based granshlaka plant Petrovsky, using as fillers

  4. Lightweight flywheel containment (United States)

    Smith, James R.


    A lightweight flywheel containment composed of a combination of layers of various material which absorb the energy of a flywheel structural failure. The various layers of material act as a vacuum barrier, momentum spreader, energy absorber, and reaction plate. The flywheel containment structure has been experimentally demonstrated to contain carbon fiber fragments with a velocity of 1,000 m/s and has an aerial density of less than 6.5 g/square centimeters. The flywheel containment, may for example, be composed of an inner high toughness structural layer, and energy absorbing layer, and an outer support layer. Optionally, a layer of impedance matching material may be utilized intermediate the flywheel rotor and the inner high toughness layer.

  5. Lightweight Trauma Module - LTM (United States)

    Hatfield, Thomas


    Current patient movement items (PMI) supporting the military's Critical Care Air Transport Team (CCATT) mission as well as the Crew Health Care System for space (CHeCS) have significant limitations: size, weight, battery duration, and dated clinical technology. The LTM is a small, 20 lb., system integrating diagnostic and therapeutic clinical capabilities along with onboard data management, communication services and automated care algorithms to meet new Aeromedical Evacuation requirements. The Lightweight Trauma Module is an Impact Instrumentation, Inc. project with strong Industry, DoD, NASA, and Academia partnerships aimed at developing the next generation of smart and rugged critical care tools for hazardous environments ranging from the battlefield to space exploration. The LTM is a combination ventilator/critical care monitor/therapeutic system with integrated automatic control systems. Additional capabilities are provided with small external modules.

  6. Performance of a New Lightweight Reciprocating Pump

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, J C


    A new four-chamber piston pump design has been fabricated and tested. The small-scale propellant pump is intended to be powered by gas at elevated temperatures, e.g. in a gas-generator cycle rocket propulsion system. Two key features are combined for the first time: leak-tight liquid-cooled seals, and a high throughput per unit hardware mass. Measured performance curves quantify flows, pressures, leakage, volumetric efficiency, and tank pressure requirements. A pair of 300-gram pumps operating with significant margin could deliver fuel and oxidizer at 5 MPa to a compact lightweight 1000-N engine, while tank pressure remains at 0.35 MPa. Pump weight is well below one percent of thrust, as is typical for launch vehicle engines. Applications include small upper stages, aggressive maneuvers in space, and miniature launch vehicles for Mars ascent.

  7. High Efficency Lightweight Radiators Project (United States)

    National Aeronautics and Space Administration — XC Associates proposes to build on prior work to develop and characterize a very high efficiency, lightweight radiator constructed from high thermal conductivity...

  8. Lightweight Inflatable Cryogenic Tank Project (United States)

    National Aeronautics and Space Administration — This proposal describes the development of an inflatable and lightweight polymer-fabric structured pressure vessel designed for the containment of cryogenic fluids....

  9. Lightweight Non-Compacting Aerogel Insulation for Cryotanks Project (United States)

    National Aeronautics and Space Administration — The exploration of space requires that new technologies be developed for long-term cryogenic propellant storage applications in-space, on the lunar surface, and on...

  10. Effects of varying podded nacelle-nozzle installations on transonic aeropropulsive characteristics of a supersonic fighter aircraft (United States)

    Capone, F. J.; Reubush, D. E.


    The aeropropulsive characteristics of an advanced twin engine fighter designed for supersonic cruise was investigated in the 16 foot Transonic Tunnel. The performance characteristics of advanced nonaxisymmetric nozzles installed in various nacelle locations, the effects of thrust induced forces on overall aircraft aerodynamics, the trim characteristics, and the thrust reverser performance were evaluated. The major model variables included nozzle power setting; nozzle duct aspect ratio; forward, mid, and aft nacelle axial locations; inboard and outboard underwing nacelle locations; and underwing and overwing nacelle locations. Thrust vectoring exhaust nozzle configurations included a wedge nozzle, a two dimensional convergent divergent nozzle, and a single expansion ramp nozzle, each with deflection angles up to 30 deg. In addition to the nonaxisymmetric nozzles, an axisymmetric nozzle installation was also tested. The use of a canard for trim was also assessed.

  11. Compact Orthoalgebras

    CERN Document Server

    Wilce, A


    We initiate a study of topological orthoalgebras (TOAs), concentrating on the compact case. Examples of TOAs include topological orthomodular lattices, and also the projection lattice of a Hilbert space. As the latter example illustrates, a lattice-ordered TOA need not be a topological lattice. However, we show that a compact Boolean TOA is a topological Boolean algebra. Using this, we prove that any compact regular TOA is atomistic, and has a compact center. We prove also that any compact TOA with isolated 0 is of finite height. We then focus on stably ordered TOAs: those in which the upper-set generated by an open set is open. These include both topological orthomodular lattices and interval orthoalgebras -- in particular, projection lattices. We show that the topology of a compact stably-ordered TOA with isolated 0 is determined by that of of its space of atoms.

  12. Lightweight hydride storage materials

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, G.J.; Guthrie, S.E.; Bauer, W. [Sandia National Labs., Livermore, CA (United States)


    The need for lightweight hydrides in vehicular applications has prompted considerable research into the use of magnesium and its alloys. Although this earlier work has provided some improved performance in operating temperature and pressure, substantial improvements are needed before these materials will significantly enhance the performance of an engineered system on a vehicle. We are extending the work of previous investigators on Mg alloys to reduce the operating temperature and hydride heat of formation in light weight materials. Two important results will be discussed in this paper: (1) a promising new alloy hydride was found which has better pressure-temperature characteristics than any previous Mg alloy and, (2) a new fabrication process for existing Mg alloys was developed and demonstrated. The new alloy hydride is composed of magnesium, aluminum and nickel. It has an equilibrium hydrogen overpressure of 1.3 atm. at 200{degrees}C and a storage capacity between 3 and 4 wt.% hydrogen. A hydrogen release rate of approximately 5 x 10{sup -4} moles-H{sub 2}/gm-min was measured at 200{degrees}C. The hydride heat of formation was found to be 13.5 - 14 kcal/mole-H{sub 2}, somewhat lower than Mg{sub 2}Ni. The new fabrication method takes advantage of the high vapor transport of magnesium. It was found that Mg{sub 2}Ni produced by our low temperature process was better than conventional materials because it was single phase (no Mg phase) and could be fabricated with very small particle sizes. Hydride measurements on this material showed faster kinetic response than conventional material. The technique could potentially be applied to in-situ hydride bed fabrication with improved packing density, release kinetics, thermal properties and mechanical stability.

  13. Compact Radiometers Expand Climate Knowledge (United States)


    To gain a better understanding of Earth's water, energy, and carbon cycles, NASA plans to embark on the Soil Moisture Active and Passive mission in 2015. To prepare, Goddard Space Flight Center provided Small Business Innovation Research (SBIR) funding to ProSensing Inc., of Amherst, Massachusetts, to develop a compact ultrastable radiometer for sea surface salinity and soil moisture mapping. ProSensing incorporated small, low-cost, high-performance elements into just a few circuit boards and now offers two lightweight radiometers commercially. Government research agencies, university research groups, and large corporations around the world are using the devices for mapping soil moisture, ocean salinity, and wind speed.

  14. Lightweight, Wearable, Metal Rubber Sensor (United States)

    Hill, Andrea


    For autonomous health monitoring. NanoSonic, Inc., has developed comfortable garments with multiple integrated sensors designed to monitor astronaut health throughout long-duration space missions. The combined high electrical conductivity, low mechanical modulus, and environmental robustness of the sensors make them an effective, lightweight, and comfortable alternative to conventional use of metal wiring and cabling.

  15. Lightweight cryptography for constrained devices

    DEFF Research Database (Denmark)

    Alippi, Cesare; Bogdanov, Andrey; Regazzoni, Francesco


    Lightweight cryptography is a rapidly evolving research field that responds to the request for security in resource constrained devices. This need arises from crucial pervasive IT applications, such as those based on RFID tags where cost and energy constraints drastically limit the solution...

  16. Lightweighted ZERODUR for telescopes (United States)

    Westerhoff, T.; Davis, M.; Hartmann, P.; Hull, T.; Jedamzik, R.


    The glass ceramic ZERODUR® from SCHOTT has an excellent reputation as mirror blank material for earthbound and space telescope applications. It is known for its extremely low coefficient of thermal expansion (CTE) at room temperature and its excellent CTE homogeneity. Recent improvements in CNC machining at SCHOTT allow achieving extremely light weighted substrates up to 90% incorporating very thin ribs and face sheets. In 2012 new ZERODUR® grades EXPANSION CLASS 0 SPECIAL and EXTREME have been released that offer the tightest CTE grades ever. With ZERODUR® TAILORED it is even possible to offer ZERODUR® optimized for customer application temperature profiles. In 2013 SCHOTT started the development of a new dilatometer setup with the target to drive the industrial standard of high accuracy thermal expansion metrology to its limit. In recent years SCHOTT published several paper on improved bending strength of ZERODUR® and lifetime evaluation based on threshold values derived from 3 parameter Weibull distribution fitted to a multitude of stress data. ZERODUR® has been and is still being successfully used as mirror substrates for a large number of space missions. ZERODUR® was used for the secondary mirror in HST and for the Wolter mirrors in CHANDRA without any reported degradation of the optical image quality during the lifetime of the missions. Some years ago early studies on the compaction effects of electron radiation on ZERODUR® were re analyzed. Using a more relevant physical model based on a simplified bimetallic equation the expected deformation of samples exposed in laboratory and space could be predicted in a much more accurate way. The relevant ingredients for light weighted mirror substrates are discussed in this paper: substrate material with excellent homogeneity in its properties, sufficient bending strengths, space radiation hardness and CNC machining capabilities.

  17. Lightweight Tunable Infrared Filter Project (United States)

    National Aeronautics and Space Administration — Michigan Aerospace Corporation has developed spaceflight qualified compact tunable Fabry-Perot interferometers for a number of applications, from ranging direct...

  18. Moisture and Thermal Conductivity of Lightweight Block Walls (United States)

    Joosep, R.


    This article examines thermal properties of lightweight block walls and their changes over the course of time. Three different types of lightweight blocks and two types of heat insulation are used in construction. Aeroc aerated concrete blocks are in use, as well as compacted LECA (Lightweight Expanded Clay Aggregate) Fibo blocks made from burned clay and Silbet blocks produced from oil shale ash. Expanded Thermisol EPS60F polystyrene plates and glass wool Isover OL-P plates are used for thermal insulation. The actual and computational values of thermal conductivity and the water draining properties of walls over time are compared in this article. Water draining from glass wool walls is relatively fast. Water-draining can take over a year in polystyrene insulated walls. All four wall constructions can be used as external walls, but care must be taken regarding the moisture content of the blocks during construction (the construction should be handled with care to minimise the moisture in the blocks), especially in polystyrene board-insulated walls.

  19. Mechanical Properties of Fiber Reinforced Lightweight Concrete Containing Surfactant

    Directory of Open Access Journals (Sweden)

    Yoo-Jae Kim


    Full Text Available Fiber reinforced aerated lightweight concrete (FALC was developed to reduce concrete's density and to improve its fire resistance, thermal conductivity, and energy absorption. Compression tests were performed to determine basic properties of FALC. The primary independent variables were the types and volume fraction of fibers, and the amount of air in the concrete. Polypropylene and carbon fibers were investigated at 0, 1, 2, 3, and 4% volume ratios. The lightweight aggregate used was made of expanded clay. A self-compaction agent was used to reduce the water-cement ratio and keep good workability. A surfactant was also added to introduce air into the concrete. This study provides basic information regarding the mechanical properties of FALC and compares FALC with fiber reinforced lightweight concrete. The properties investigated include the unit weight, uniaxial compressive strength, modulus of elasticity, and toughness index. Based on the properties, a stress-strain prediction model was proposed. It was demonstrated that the proposed model accurately predicts the stress-strain behavior of FALC.

  20. Lightweight Space Tug body structure (United States)

    Lager, J. R.


    Lightweight honeycomb sandwich construction using a wide variety of metal and fibrous composite faceskins was used in the design of a typical Space Tug skirt structure. Relatively low magnitude combined loading of axial compression and torsion resulted in designs using ultrathin faceskins, lightweight honeycomb cores, and thin faceskin/core adhesive bond layers. Two of the designs with metal faceskins (aluminum and titanium) and four with fibrous composite faceskins (using combinations of fiberglass, boron, and graphite) were evaluated through the fabrication and structural test of a series of small development panels. The two most promising concepts with aluminum and graphite/epoxy faceskins, were further evaluated through the fabrication and structural test of larger compression and shear panels. All panels tested exceeded design ultimate load levels, thereby, verifying the structural integrity of the selected designs. Projected skirt structural weights for the graphite/epoxy and aluminum concepts fall within original weight guidelines established for the Space Tug vehicle.

  1. A compact self-recording pressure based sea level gauge suitable for deployments at harbour and offshore environments

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, E.; Peshwe, V.B.; Joseph, A.; Mehra, P.; Naik, G.P.; Kumar, V.; Desa, E.S.; Desai, R.G.P.; Nagvekar, S.; Desai, S.P.

    A compact and lightweight self-recording pressure based sea level gauge has been designed to suit deployments from harbour and offshore environments. A novel hydraulic coupling device designed in-house was used to transfer the seawater pressure...

  2. Making Lightweight Structures By Vapor Deposition (United States)

    Goela, Jitendra S.; Pickering, Michael A.; Taylor, Raymond L.


    Technique developed for fabrication of stiff, strong, lightweight structures of silicon carbide or other materials by any of several deposition processes. Structures made by method can have complicated shapes. Ability to manufacture complex shape from pure deposited SiC useful and leads to new products in several fields. These lightweight structures used as backup structures for optical components, as structural components in automotive, aerospace, and outer space applications, and as lightweight parts of furniture for outer space.

  3. Aeropropulsive characteristics of Mach numbers up to 2.2 of axisymmetric and nonaxisymmetric nozzles installed on an F-18 model (United States)

    Capone, F. J.


    An investigation to determine the aeropropulsive characteristics of nonaxisymmetric nozzles on an F-18 jet effects model was conducted in the Langley 16-foot transonic tunnel and the AEDC 16-foot supersonic wind tunnel. The performance of a two dimensional convergent-divergent nozzle, a single expansion ramp nozzle, and a wedge nozzle was compared with that of the baseline axisymmetric nozzle. Test data were obtained at static conditions and at Mach numbers from 0.60 to 2.20 at an angle of attack of 0 deg. Nozzle pressure ratio was varied from jet-off to about 20.

  4. Modular Self-Rigidizing Lightweight Structures Project (United States)

    National Aeronautics and Space Administration — An innovative structures concept has been developed that uses space qualified flexible thin film polyimide to produce ultra-lightweight inflation deployed...

  5. Lightweight and Energy Efficient Heat Pump Project (United States)

    National Aeronautics and Space Administration — Future Spacecraft from the JPL will require increasingly sophisticated thermal control technology. A need exists for efficient, lightweight Vapor Compression Cycle...

  6. Compact Vortices

    CERN Document Server

    Bazeia, D; Marques, M A; Menezes, R; Zafalan, I


    We study a family of Maxwell-Higgs models, described by the inclusion of a function of the scalar field that represent generalized magnetic permeability. We search for vortex configurations which obey first-order differential equations that solve the equations of motion. We first deal with the asymptotic behavior of the field configurations, and then implement a numerical study of the solutions, the energy density and the magnetic field. We work with the generalized permeability having distinct profiles, giving rise to new models, and we investigate how the vortices behave, compared with the solutions of the corresponding standard models. In particular, we show how to build compact vortices, that is, vortex solutions with the energy density and magnetic field vanishing outside a compact region of the plane.

  7. Compact NMR

    Energy Technology Data Exchange (ETDEWEB)

    Bluemich, Bernhard; Haber-Pohlmeier, Sabina; Zia, Wasif [RWTH Aachen Univ. (Germany). Inst. fuer Technische und Makromolekulare Chemie (ITMC)


    Nuclear Magnetic Resonance (NMR) spectroscopy is the most popular method for chemists to analyze molecular structures, while Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic tool for medical doctors that provides high-contrast images of biological tissue. In both applications, the sample (or patient) is positioned inside a large, superconducting magnet to magnetize the atomic nuclei. Interrogating radio-frequency pulses result in frequency spectra that provide the chemist with molecular information, the medical doctor with anatomic images, and materials scientist with NMR relaxation parameters. Recent advances in magnet technology have led to a variety of small permanent magnets to allow compact and low-cost instruments. The goal of this book is to provide an introduction to the practical use of compact NMR at a level nearly as basic as the operation of a smart phone.

  8. Manufacturing Precise, Lightweight Paraboloidal Mirrors (United States)

    Hermann, Frederick Thomas


    A process for fabricating a precise, diffraction- limited, ultra-lightweight, composite- material (matrix/fiber) paraboloidal telescope mirror has been devised. Unlike the traditional process of fabrication of heavier glass-based mirrors, this process involves a minimum of manual steps and subjective judgment. Instead, this process involves objectively controllable, repeatable steps; hence, this process is better suited for mass production. Other processes that have been investigated for fabrication of precise composite-material lightweight mirrors have resulted in print-through of fiber patterns onto reflecting surfaces, and have not provided adequate structural support for maintenance of stable, diffraction-limited surface figures. In contrast, this process does not result in print-through of the fiber pattern onto the reflecting surface and does provide a lightweight, rigid structure capable of maintaining a diffraction-limited surface figure in the face of changing temperature, humidity, and air pressure. The process consists mainly of the following steps: 1. A precise glass mandrel is fabricated by conventional optical grinding and polishing. 2. The mandrel is coated with a release agent and covered with layers of a carbon- fiber composite material. 3. The outer surface of the outer layer of the carbon-fiber composite material is coated with a surfactant chosen to provide for the proper flow of an epoxy resin to be applied subsequently. 4. The mandrel as thus covered is mounted on a temperature-controlled spin table. 5. The table is heated to a suitable temperature and spun at a suitable speed as the epoxy resin is poured onto the coated carbon-fiber composite material. 6. The surface figure of the optic is monitored and adjusted by use of traditional Ronchi, Focault, and interferometric optical measurement techniques while the speed of rotation and the temperature are adjusted to obtain the desired figure. The proper selection of surfactant, speed or rotation

  9. Small and lightweight power amplifiers (United States)

    Shams, Qamar A.; Barnes, Kevin N.; Fox, Robert L.; Moses, Robert W.; Bryant, Robert G.; Robinson, Paul C.; Shirvani, Mir


    The control of u wanted structural vibration is implicit in most of NASA's programs. Currently several approaches to control vibrations in large, lightweight, deployable structures and twin tail aircraft at high angles of attack are being evaluated. The Air Force has been examining a vertical tail buffet load alleviation system that can be integrated onboard an F/A-18 and flown. Previous wind tunnel and full-scale ground tests using distributed actuators have shown that the concept works; however, there is insufficient rom available onboard an F/A-18 to store current state-of- the-art system components such as amplifiers, DC-to-DC converter and a computer for performing vibration suppression. Sensor processing, power electronics, DC-to-DC converters, and control electronics that may be collocated with distributed actuators, are particularly desirable. Such electronic system would obviate the need for complex, centralized, control processing and power distribution components that will eliminate the weight associated with lengthy wiring and cabling networks. Several small and lightweight power amplifiers ranging from 300V pp to 650V pp have been designed using off the shelf components for different applications. In this paper, the design and testing of these amplifiers will be presented under various electrical loads.



    Budi Darma Laksana; Cherry Galatia Ballangan


    In this paper, a light-weight MVC framework for smart device application is designed and implemented. The primary goal of the work is to provide a MVC framework for a commercial smart device product development. To this end, the developed framework presents integration between the classic design patterns, MVC and state-of-the-art technology XAML by adapting a MVC framework of an open source XAML efforts, MyXaml into .NET Compact Framework. As the compact framework only comprises 12% of .NET F...

  11. PICO : An Ultra Lightweight and Low Power Encryption Design for Ubiquitous Computing

    Directory of Open Access Journals (Sweden)

    Gaurav Bansod


    Full Text Available An ultra-lightweight, a very compact block cipher ‘PICO’ is proposed. PICO is a substitution and permutation based network, which operates on a 64 bit plain text and supports a key length of 128 bits. It has a compact structure and requires 1877 GEs. Its innovative design helps to generate a large number of active S - boxes in fewer rounds which can thwart the linear and differential attacks on the cipher. PICO shows good performance on both the hardware and the software platforms. PICO consumes only 2504 bytes of Flash memory which is less than the ultra-lightweight cipher PRESENT. PICO has a very strong substitution layer (S-box which not only makes the design robust but also introduces a great avalanche effect. PICO has a strong and compact key scheduling which is motivated by the latest cipher SPECK designed by NSA. PICO consumes 28 mW of dynamic power which is less than the PRESENT cipher (38 mW. The security analysis of PICO and its performance as an ultra-lightweight cipher are presented. 

  12. RFID security a lightweight paradigm

    CERN Document Server

    Khattab, Ahmed; Amini, Esmaeil; Bayoumi, Magdy


    This book provides a comprehensive treatment of security in the widely adopted, Radio Frequency Identification (RFID) technology. The authors present the fundamental principles of RFID cryptography in a manner accessible to a broad range of readers, enabling them to improve their RFID security design. This book also offers the reader a range of interesting topics portraying the current state-of-the-art in RFID technology and how it can be integrated with today’s Internet of Things (IoT) vision. The authors describe a first-of-its-kind, lightweight symmetric authenticated encryption cipher called Redundant Bit Security (RBS), which enables significant, multi-faceted performance improvements compared to existing cryptosystems. This book is a must-read for anyone aiming to overcome the constraints of practical implementation in RFID security technologies.

  13. Large Lightweight Mirrors Controlled by Dielectric Elastomer Artifical Muscle (United States)

    Kornbluh, R. D.; Flamm, D. S.; Vujkovic-Civijin, P.; Pelrine, R. E.; Huestis, D. L.


    We will describe a new concept for control of the lightweight large-aperture mirrors that will be required for future space-based astronomy and remote sensing applications. To be cost effective and practical, such optical systems must be lightweight and capable of deployment from highly compacted stowed configurations. Optical systems based on membrane mirrors or other lightweight structures can address some of these needs, but such flexible gossamer structures present challenges in achieving and maintaining the required shape or figure. For the past 9 years SRI has been exploring dielectric elastomer artifical muscle technology for active control of objects and structures [1-2]. The basic functional element is a thin polymer film coated on both sides by a compliant electrode material. When voltage is applied between the top and bottom electrodes, an electrostrictive compressive force squeezes the film, causing it to expand in area. The induced forces are related to the square of the voltage. If we assemble a large mirror from numerous independently addressable elements, sophisticated control is possible, even including adaptive optics. Dielectric elastomers have many advantages over other electroactive polymers and other smart-materials actuation technologies that have been considered in the past. For example, from many candidate materials we can choose ones with high planar strains, low power dissipation, tolerance of the space environment, and ease of commercial fabrication into large sheets. [1] R. Pelrine, R. Kornbluh, Q. Pei, and J. Joseph, Science 287, 386 (2000). [2] R. Pelrine, P. Sommer-Larson, R. Kornbluh, R. Heydt, G. Kofod, Q. Pei, and P. Gravesen, in Smart Structures and Materials 2001: Electroactive Polymer Actuators and Devices, ed. Y. Bar-Cohen, Proc. SPIE 4329, 335 (2001).

  14. A novel lightweight Fizeau infrared interferometric imaging system (United States)

    Hope, Douglas A.; Hart, Michael; Warner, Steve; Durney, Oli; Romeo, Robert


    Aperture synthesis imaging techniques using an interferometer provide a means to achieve imagery with spatial resolution equivalent to a conventional filled aperture telescope at a significantly reduced size, weight and cost, an important implication for air- and space-borne persistent observing platforms. These concepts have been realized in SIRII (Space-based IR-imaging interferometer), a new light-weight, compact SWIR and MWIR imaging interferometer designed for space-based surveillance. The sensor design is configured as a six-element Fizeau interferometer; it is scalable, light-weight, and uses structural components and main optics made of carbon fiber replicated polymer (CFRP) that are easy to fabricate and inexpensive. A three-element prototype of the SIRII imager has been constructed. The optics, detectors, and interferometric signal processing principles draw on experience developed in ground-based astronomical applications designed to yield the highest sensitivity and resolution with cost-effective optical solutions. SIRII is being designed for technical intelligence from geo-stationary orbit. It has an instantaneous 6 x 6 mrad FOV and the ability to rapidly scan a 6x6 deg FOV, with a minimal SNR. The interferometric design can be scaled to larger equivalent filled aperture, while minimizing weight and costs when compared to a filled aperture telescope with equivalent resolution. This scalability in SIRII allows it address a range of IR-imaging scenarios.

  15. Average density and porosity of high-strength lightweight concrete

    Directory of Open Access Journals (Sweden)

    A.S. Inozemtcev


    Full Text Available The analysis results of high-strength lightweight concrete (HSLWC structure are presented in this paper. The X-ray tomography, optical microscopy and other methods are used for researching of average density and porosity. It has been revealed that mixtures of HSLWC with density 1300…1500 kg/m3 have a homogeneous structure. The developed concrete has a uniform distribution of the hollow filler and a uniform layer of cement-mineral matrix. The highly saturated gas phase which is divided by denser large particles of quartz sand and products of cement hydration in the contact area allow forming a composite material with low average density, big porosity (up to 40% and high strength (compressive strength is more than 40 MPa. Special modifiers increase adhesion, compacts structure in the contact area, decrease water absorption of high-strength lightweight concrete (up to 1 % and ensure its high water resistance (water resistance coefficient is more than 0.95.

  16. Lightweight composite mirrors for telescopes Project (United States)

    National Aeronautics and Space Administration — Lightweight, steady and stiff mirrors are necessary to decrease cost of telescopes such as IXO and GenX used in special NASA missions. Low-density materials are...

  17. Lightweight Composite Materials for Heavy Duty Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Pruez, Jacky; Shoukry, Samir; Williams, Gergis; Shoukry, Mark


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

  18. Aluminum-CNF Lightweight Radiator Components Project (United States)

    National Aeronautics and Space Administration — This proposal relates to a new materials concept for an aluminum-carbon nanofiber composite, high thermal conductivity ultra lightweight material that will form the...

  19. Vibro-acoustics of lightweight sandwich structures

    CERN Document Server

    Lu, Tianjian


    Vibro-Acoustics of Lightweight Sandwich Structures introduces the study of the coupled vibration and acoustic behavior of lightweight sandwich structures in response to harmonic force and sound pressure. This book focuses on the theoretical modeling and experimental investigation of lightweight sandwich structures in order to provide a predictive framework for vibro-acoustic characteristics of typical engineering structures. Furthermore, by developing solution tools, it concentrates on the influence of key systematic parameters leading to effective guidance for optimal structure design toward lightweight, high-stiffness and superior sound insulation capability. This book is intended for researchers, scientists, engineers and graduate students in mechanical engineering especially in structural mechanics, mechanics and acoustics. Fengxian Xin and Tianjian Lu both work at the School of Aerospace, Xi’an Jiaotong University.

  20. Novel Lightweight Magnets for Space Applications Project (United States)

    National Aeronautics and Space Administration — TYRC of Tallahassee, Florida will design, fabricate and test a novel magnet for space applications. This lightweight magnet will be designed to operate at higher...

  1. Lightweight, High-Temperature Radiator Panels Project (United States)

    National Aeronautics and Space Administration — Lightweight, high-temperature radiators are needed for future, high-efficiency power conversion systems for Nuclear Electric Propulsion (NEP). Creare has developed...


    Directory of Open Access Journals (Sweden)

    Marius C. BARBU


    Full Text Available Lightweight boards and beams in the wood-based construction and furniture industry are not a new topic. The density reduction of panels using sandwich structure with light cores was confirmed by users like doors or mobile homes more than three decades ago. Today many ways to attain a lighter wooden structure are on offer, partially in industrial application. The first one is the use of light-weight wood species like balsa, lime, pine from southern hemisphere plantations etc. limited by the availability, strength properties, gluability and so on. A second one is the sandwich structure made from hard faces like thick veneer, thin plywood, particleboard or high density thin fiberboard and cores made from honeycomb paper, very light wood species or foams like the polystyrene one. A third way to produce a light structure is to reduce the core drastically, using predesigned skeletons with special shapes and connections to the faces. The engines for these developments are on the one hand the fast growing market of knockdown furniture and on the other hand the increasing costs for energy and raw materials. Additional factors that make weight saving a primary economical objective for most producers are transportation costs, easier handling and higher acceptance among the end users. Moreover, customers demand more for ergonomical solutions regarding packaging. Many patents were generated by researchers and developers for new one-stage production processes for sandwich panels with wood- and impregnated paper-based facings made from veneers, particles or fibres and a core consisting of expandable foams, particles or embedded hard skeletons. These ideas or prototypes could be integrated in existing continuous pressing lines for wood based panels keeping some of the advantages of the continuous production technique in matters of efficiency. Some of the challenges of the light weight wooden structure are the connection in half or final parts, resistance to

  3. The Micro-Instrumentation Package: A Solution to Lightweight Ballooning (United States)

    Juneau, Jill

    This paper discusses the design and testing of an over the horizon (OTH) light weight telemetry and termination system that can be used for small ballooning payloads. Currently, the Columbia Scientific Balloon Facility (CSBF) provides telemetry for the science payload by integrating one of two types of support packages. The type of support package integrated depends on whether the flight will stay in range of line of sight (LOS) or will exceed LOS requiring the use of over the horizon (OTH) telemetry. The weights of these systems range from 100 pounds to 350 pounds depending upon the use of redundant systems, equipment for high data rates, and batteries and/or solar panels for power requirements. These weight values are not as significant for larger payloads but can be crippling for smaller payloads. In addition, these support package systems are fairly expensive, placing a high importance on recovery. A lightweight and inexpensive telemetry system could be beneficial for various reasons. First, it would allow scientists to fly lightweight payloads on large balloons reaching even higher altitudes. Second, scientists could fly lightweight payloads on less expensive balloons such as meteorological balloons. Depending on the payload, these flights could be fairly inexpensive and even disposable. Third, a compact telemetry system on any balloon will free up more room for the science portion of the payload. In response, a compact telemetry/termination system called the Micro-Instrumentation Package (MIP) was developed. The MIP provides uplink and downlink communications, an interface to the science, housekeeping information including global positioning system (GPS) position, and relays. Instead of a power-hungry microprocessor, the MIP's central consists of a microcontroller. Microcontrollers are lower power, easily programmed, and can be purchased for less than ten dollars. For uplink and downlink telemetry, the MIP uses an LOS serial transceiver and an Iridium unit


    DEFF Research Database (Denmark)

    Brunskog, Jonas; Lhomond, Alice; Ohlrich, Mogens


    In this paper the attenuation and flanking transmissions of impact noise in lightweight building structures is studied using a modal approach. The structural field is mainly analysed, putting the main attention to the parts being important in the modelling. The amount of attenuation produced...... by the periodically reinforcing beams used in lightweight building structures is analysed. The consequence of these factors in modelling flanking transmission is also discussed....

  5. Aeropropulsive characteristics of twin nonaxisymmetric vectoring nozzles installed with forward-swept and aft-swept wings. [in the Langley 16 Foot Transonic Tunnel (United States)

    Capone, F. J.


    An investigation was conducted in the Langley 16 Foot Transonic Tunnel to determine the aeropropulsive characteristics of a single expansion ramp nozzle (SERN) and a two dimensional convergent divergent nozzle (2-D C-D) installed with both an aft swept and a forward swept wing. The SERN was tested in both an upright and an inverted position. The effects of thrust vectoring at nozzle vector angles from -5 deg to 20 deg were studied. This investigation was conducted at Mach numbers from 0.40 to 1.20 and angles of attack from -2.0 deg to 16 deg. Nozzle pressure ratio was varied from 1.0 (jet off) to about 9.0. Reynolds number based on the wing mean geometric chord varied from about 3 million to 4.8 million, depending upon free stream number.

  6. Compact, Stiff, Remotely-Actuable Quick-Release Clamp (United States)

    Tsai, Ted W. (Inventor)


    The present invention provides a clamp that is compact and lightweight, yet provides high holding strength and stiffness or rigidity. The clamp uses a unique double slant interface design which provides mechanical advantages to resist forces applied to the clamp member as the load increases. The clamp allows for rapid and remote-activated release of the clamp jaws by applying only a small operating force to an over-center lock/release mechanism, such as by pulling a manual tether.

  7. Compact networked radars for Army unattended ground sensors (United States)

    Wikner, David A.; Viveiros, Edward A.; Wellman, Ronald; Clark, John; Kurtz, Jim; Pulskamp, Jeff; Proie, Robert; Ivanov, Tony; Polcawich, Ronald G.; Adler, Eric D.


    The Army Research Laboratory is in partnership with the University of Florida - Electronics Communications Laboratory to develop compact radar technology and demonstrate that it is scalable to a variety of ultra-lightweight platforms (<10 lbs.) to meet Army mission needs in persistent surveillance, unattended ground sensor (UGS), unmanned systems, and man-portable sensor applications. The advantage of this compact radar is its steerable beam technology and relatively long-range capability compared to other small, battery-powered radar concepts. This paper will review the ongoing development of the sensor and presents a sample of the collected data thus far.

  8. Development of a Tendon-Actuated Lightweight In-Space MANipulator (TALISMAN) (United States)

    Doggett, William R.; Dorsey, John T.; Jones, Thomas C.; King, Bruce


    An invention of a new and novel space robotic manipulator is described. By using a combination of lightweight truss links, a novel hinge joint, tendon-articulation and passive tension stiffening, this new robotic manipulator architecture achieves compact packaging, high strength, stiffness and dexterity while being very lightweight compared to conventional manipulators. The manipulator is also very modular; easy to scale for different reach, load and stiffness requirements; enabling customization for a diverse set of applications. Novel features of the new manipulator concept are described as well as some of the approaches to implement these design features. Two diverse applications are presented to show the versatility of the concept. First generation prototype hardware was designed, manufactured and has been assembled into a working manipulator that is being used to refine and extend development efforts.

  9. Geopolymerization of lightweight aggregate waste

    Directory of Open Access Journals (Sweden)

    Labrincha, J. A.


    Full Text Available Geopolymerization is a viable way to process and re-use alumino-silicate industrial waste while producing highstrength, high chemical inertia materials that can effectively immobilize other industrial by-products, and even hazardous waste. In this study industrial waste from different stages of the manufacture of lightweight expanded clay aggregate was characterized for its possible transformation, via alkali activation, to geopolymers. The ultimate aim was to assess the possibility of using such geopolymers to develop thermal and acoustic insulation panels. The containment of hazardous materials is another important application for these new materials. Geopolymers were prepared for this study with different particles size distributions and activator concentrations. Their mechanical properties, composition and microstructure were characterized and a material with promising insulating properties was produced. A preliminary analysis was conducted of the salt formation observed in these geopolymers, the chief drawback to their use.La geopolimerización es una manera viable para procesar y agregar valor a los residuos industriales de alumino-silicato dando lugar a materiales con elevadas resistencias mecánmicas, alta inercia química y que permiten encapsular otros residuos, incluso peligrosos. Los residuos industriales que proceden de diversos tipos de arcillas para la fabricación de áridos ligeros se han caracterizado para la producción de geopolímeros mediante el proceso de ataque alcalino. Su incorporación en una matriz geopolimérica permite la posibilidad de desarrollo de paneles de aislamiento (térmico y acústico. Además, la inmovilización de materiales peligrosos es un logro adicional importante. Los geopolímeros se han producido con fórmulas diferentes y se han caracterizado sus propiedades mecánicas, composición y microestructura, para dar lugar a una composición interesante con propiedades aislantes. Se ha llevado a cabo

  10. Exploring Energy Efficiency of Lightweight Block Ciphers

    DEFF Research Database (Denmark)

    Banik, Subhadeep; Bogdanov, Andrey; Regazzoni, Francesco


    lightweight block ciphers, and thereby try to predict the optimal value of r at which an r-round unrolled architecture for a cipher is likely to be most energy efficient. We also try to relate our results to some physical design parameters like the signal delay across a round and algorithmic parameters like......In the last few years, the field of lightweight cryptography has seen an influx in the number of block ciphers and hash functions being proposed. One of the metrics that define a good lightweight design is the energy consumed per unit operation of the algorithm. For block ciphers, this operation...... is the encryption of one plaintext. By studying the energy consumption model of a CMOS gate, we arrive at the conclusion that the energy consumed per cycle during the encryption operation of an r-round unrolled architecture of any block cipher is a quadratic function in r. We then apply our model to 9 well known...

  11. A lightweight shape-memory magnesium alloy. (United States)

    Ogawa, Yukiko; Ando, Daisuke; Sutou, Yuji; Koike, Junichi


    Shape-memory alloys (SMAs), which display shape recovery upon heating, as well as superelasticity, offer many technological advantages in various applications. Those distinctive behaviors have been observed in many polycrystalline alloy systems such as nickel titantium (TiNi)-, copper-, iron-, nickel-, cobalt-, and Ti-based alloys but not in lightweight alloys such as magnesium (Mg) and aluminum alloys. Here we present a Mg SMA showing superelasticity of 4.4% at -150°C and shape recovery upon heating. The shape-memory properties are caused by reversible martensitic transformation. This Mg alloy includes lightweight scandium, and its density is about 2 grams per cubic centimeter, which is one-third less than that of practical TiNi SMAs. This finding raises the potential for development and application of lightweight SMAs across a number of industries.

  12. The Design of a Lightweight RFID Middleware

    Directory of Open Access Journals (Sweden)

    Fengqun Lin


    Full Text Available Radio Frequency Identification (RFID middleware is often regarded as the central nervous system of RFID systems. In this paper, a lightweight RFID middleware is designed and implemented without the need of an Application Level Events (ALE structure, and its implementation process is described using a typical commerical enterprise. A short review of the current RFID middleware research and development is also included. The characteristics of RFID middleware are presented with a two-centric framework. The senarios of RFID data integration based on the simplified structure are provided to illuminats the design and implementation of the lightweight middleware structure and its development process. The lightweight middleware is easy to maintain and extend because of the simplified and streamlined structure and the short development cycle.

  13. Infinte Periodic Structure of Lightweight Elements

    DEFF Research Database (Denmark)

    Domadiya, Parthkumar Gandalal; Andersen, Lars Vabbersgaard; Sorokin, Sergey


    Lightweight wooden structures have become more popular as a sustainable, environmental- friendly and cost-effective alternative to concrete, steel and masonry buildings. However, there are certain drawbacks regarding noise and vibration due to the smaller weight and stiffness of wooden buildings...... for proper dynamic assessment of lightweight buildings. Instead, this paper discusses and compares the use of finite element analysis and a wave approach based on Floquet theory. The present analysis has focus on the effect of periodicity on vibration transmission within semi-infinite beam structures. Two....... Furthermore, lightweight building elements are typically periodic structures that behave as filters for sound propagation within certain frequency ranges (stop bands), thus only allowing transmission within the pass bands. Hence, traditional methods based on statistical energy analysis cannot be used...


    DEFF Research Database (Denmark)


    The invention relates to a light-weight load-bearing structure (1) with optimized compression zone (2), where along one or more compression zones (2) in the structure (1) to be cast a core (3) of strong concrete is provided, which core (3) is surrounded by concrete of less strength (4) compared...... to the core (3) of strong concrete. The invention also relates to a method of casting of light-weight load-bearing structures (1) with optimized compression zone (2) where one or more channels, grooves, ducts, pipes and/or hoses (5) formed in the load-bearing structure (1) serves as moulds for moulding one...... or more cores (3) of strong concrete in the light-weight load-bearing structure (1)....

  15. Compaction Behavior of Isomalt after Roll Compaction



    The suitability of the new isomalt grade galenIQ™ 801 for dry granulation and following tableting is evaluated in this study. Isomalt alone, as well as a blend of equal parts with dibasic calcium phosphate, is roll compacted and tableted. Particle size distribution and flowability of the granules and friability and disintegration time of the tablets are determined. Tensile strength of tablets is related to the specific compaction force during roll compaction and the tableting force....

  16. Southern Regional Center for Lightweight Innovative Design

    Energy Technology Data Exchange (ETDEWEB)

    Horstemeyer, Mark F. [Mississippi State Univ., Mississippi State, MS (United States); Wang, Paul [Mississippi State Univ., Mississippi State, MS (United States)


    The three major objectives of this Phase III project are: To develop experimentally validated cradle-to-grave modeling and simulation tools to optimize automotive and truck components for lightweighting materials (aluminum, steel, and Mg alloys and polymer-based composites) with consideration of uncertainty to decrease weight and cost, yet increase the performance and safety in impact scenarios; To develop multiscale computational models that quantify microstructure-property relations by evaluating various length scales, from the atomic through component levels, for each step of the manufacturing process for vehicles; and To develop an integrated K-12 educational program to educate students on lightweighting designs and impact scenarios.

  17. Environmental assessment of lightweight electric vehicles

    CERN Document Server

    Egede, Patricia


    This monograph adresses the challenge of the environmental assessment of leightweight electric vehicles. It poses the question whether the use of lightweight materials in electric vehicles can reduce the vehicles’ environmental impact and compares the environmental performance of a lightweight electric vehicle (LEV) to other types of vehicles. The topical approach focuses on methods from life cycle assessment (LCA), and the book concludes with a comprehensive concept on the environmental assessment of LEVs. The target audience primarily comprises LCA practitioners from research institutes and industry, but it may also be beneficial for graduate students specializing in the field of environmental assessment.

  18. High-Pressure Lightweight Thrusters (United States)

    Holmes, Richard; McKechnie, Timothy; Shchetkovskiy, Anatoliy; Smirnov, Alexander


    Returning samples of Martian soil and rock to Earth is of great interest to scientists. There were numerous studies to evaluate Mars Sample Return (MSR) mission architectures, technology needs, development plans, and requirements. The largest propulsion risk element of the MSR mission is the Mars Ascent Vehicle (MAV). Along with the baseline solid-propellant vehicle, liquid propellants have been considered. Similar requirements apply to other lander ascent engines and reaction control systems. The performance of current state-ofthe- art liquid propellant engines can be significantly improved by increasing both combustion temperature and pressure. Pump-fed propulsion is suggested for a single-stage bipropellant MAV. Achieving a 90-percent stage propellant fraction is thought to be possible on a 100-kg scale, including sufficient thrust for lifting off Mars. To increase the performance of storable bipropellant rocket engines, a high-pressure, lightweight combustion chamber was designed. Iridium liner electrodeposition was investigated on complex-shaped thrust chamber mandrels. Dense, uniform iridium liners were produced on chamber and cylindrical mandrels. Carbon/carbon composite (C/C) structures were braided over iridium-lined mandrels and densified by chemical vapor infiltration. Niobium deposition was evaluated for forming a metallic attachment flange on the carbon/ carbon structure. The new thrust chamber was designed to exceed state-of-the-art performance, and was manufactured with an 83-percent weight savings. High-performance C/Cs possess a unique set of properties that make them desirable materials for high-temperature structures used in rocket propulsion components, hypersonic vehicles, and aircraft brakes. In particular, more attention is focused on 3D braided C/Cs due to their mesh-work structure. Research on the properties of C/Cs has shown that the strength of composites is strongly affected by the fiber-matrix interfacial bonding, and that weakening

  19. Efficient and lightweight current leads (United States)

    Bromberg, L.; Dietz, A. J.; Michael, P. C.; Gold, C.; Cheadle, M.


    Current leads generate substantial cryogenic heat loads in short length High Temperature Superconductor (HTS) distribution systems. Thermal conduction, as well as Joule losses (I2R) along the current leads, comprises the largest cryogenic loads for short distribution systems. Current leads with two temperature stages have been designed, constructed and tested, with the goal of minimizing the electrical power consumption, and to provide thermal margin for the cable. We present the design of a two-stage current lead system, operating at 140 K and 55 K. This design is very attractive when implemented with a turbo-Brayton cycle refrigerator (two-stage), with substantial power and weight reduction. A heat exchanger is used at each temperature station, with conduction-cooled stages in-between. Compact, efficient heat exchangers are challenging, because of the gaseous coolant. Design, optimization and performance of the heat exchangers used for the current leads will be presented. We have made extensive use of CFD models for optimizing hydraulic and thermal performance of the heat exchangers. The methodology and the results of the optimization process will be discussed. The use of demountable connections between the cable and the terminations allows for ease of assembly, but require means of aggressively cooling the region of the joint. We will also discuss the cooling of the joint. We have fabricated a 7 m, 5 kA cable with second generation HTS tapes. The performance of the system will be described.

  20. FY 2012 Lightweight Materials Annual Report

    Energy Technology Data Exchange (ETDEWEB)



    The FY 2012 Annual Progress Report for Lightweight Materials provides a detailed description of the activities and technical accomplishments which focuses on the development and validation of advanced materials and manufacturing technologies to significantly reduce light and heavy duty vehicle weight without compromising other attributes such as safety, performance, recyclability, and cost.

  1. Cryptanalysis of Some Lightweight Symmetric Ciphers

    DEFF Research Database (Denmark)

    Abdelraheem, Mohamed Ahmed Awadelkareem Mohamed Ahmed

    on a variant of PRESENT with identical round keys. We propose a new attack named the Invariant Subspace Attack that was specifically mounted against the lightweight block cipher PRINTcipher. Furthermore, we mount several attacks on a recently proposed stream cipher called A2U2....

  2. A Lightweight Mobile RSVP for Unicast

    Institute of Scientific and Technical Information of China (English)

    CHEN Wen; LEI Fei-yu; CHEN Xi; WANG Wei-nong


    This paper presents a lighter protocol, and it removes the multicast burdens from RSVP to adapt to unicast applications. At the same time, when RSVP is used in wireless networks, some issues about mobility raise popular concerns. The proposed protocol a lightweight mobile RSVP protocol, solves the problems by the following mechanisms:changeless flow identifier, a new state management and "refresh" mechanism.

  3. Lightweight concrete with enhanced neutron shielding

    Energy Technology Data Exchange (ETDEWEB)

    Brindza, Paul Daniel; Metzger, Bert Clayton


    A lightweight concrete containing polyethylene terephthalate in an amount of 20% by total volume. The concrete is enriched with hydrogen and is therefore highly effective at thermalizing neutrons. The concrete can be used independently or as a component of an advanced neutron radiation shielding system.

  4. Lightweight solar concentrator structures, phase 2 (United States)

    Williams, Brian E.; Kaplan, Richard B.


    This report summarizes the results of the program conducted by Ultramet under SBIR Phase 2 Contract NAS3-25418. The objective of this program was to develop lightweight materials and processes for advanced high accuracy Space Solar Concentrators using rigidized foam for the substrate structure with an integral optical surface.

  5. Method of fabricating lightweight honeycomb structures (United States)

    Goela, Jitendra S. (Inventor); Pickering, Michael (Inventor); Taylor, Raymond L. (Inventor)


    A process is disclosed for fabricating lightweight honeycomb type structures out of material such as silicon carbide (SiC) and silicon (S). The lightweight structure consists of a core to define the shape and size of the structure. The core is coated with an appropriate deposit such as SiC or Si to give the lightweight structure strength and stiffness and for bonding the lightweight structure to another surface. The core is fabricated from extremely thin ribs of appropriately stiff and strong material such as graphite. First, a graphite core consisting of an outer hexagonal cell with six inner triangular cells is constructed from the graphite ribs. The graphite core may be placed on the back-up side of a SiC faceplate and then coated with SiC to produce a monolithic structure without the use of any bonding agent. Cores and methods for the fabrication thereof in which the six inner triangular cells are further divided into a plurality of cells are also disclosed.

  6. Vehicle Lightweighting: 40% and 45% Weight Savings Analysis: Technical Cost Modeling for Vehicle Lightweighting

    Energy Technology Data Exchange (ETDEWEB)

    Mascarin, Anthony [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hannibal, Ted [Idaho National Lab. (INL), Idaho Falls, ID (United States); Raghunathan, Anand [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ivanic, Ziga [Idaho National Lab. (INL), Idaho Falls, ID (United States); Francfort, James [Idaho National Lab. (INL), Idaho Falls, ID (United States)


    The U.S. Department of Energy’s Vehicle Technologies Office, Materials area commissioned a study to model and assess manufacturing economics of alternative design and production strategies for a series of lightweight vehicle concepts. The strategic targets were a 40% and a 45% mass reduction relative to a standard North American midsize passenger sedan at an effective cost of $3.42 per pound (lb) saved. The baseline vehicle was an average of several available vehicles in this class. Mass and cost breakdowns from several sources were used, including original equipment manufacturers’ (OEMs’) input through U.S. Department of Energy’s Vehicle Technologies Office programs and public presentations, A2Mac1 LLC’s teardown information, Lotus Engineering Limited and FEV, Inc. breakdowns in their respective lightweighting studies, and IBIS Associates, Inc.’s decades of experience in automotive lightweighting and materials substitution analyses. Information on lightweighting strategies in this analysis came from these same sources and the ongoing U.S. Department of Energy-funded Vehma International of America, Inc. /Ford Motor Company Multi-Material Lightweight Prototype Vehicle Demonstration Project, the Aluminum Association Transportation Group, and many United States Council for Automotive Research’s/United States Automotive Materials Partnership LLC lightweight materials programs.

  7. On Compact Graphs

    Institute of Scientific and Technical Information of China (English)

    Ping WANG; Jiong Sheng LI


    Let G be a finite simple graph with adjacency matrix A, and let P(A) be the convex closure of the set of all permutation matrices commuting with A. G is said to be compact if every doubly stochastic matrix which commutes with A is in P(A). In this paper, we characterize 3-regular compact graphs and prove that if G is a connected regular compact graph, G - v is also compact, and give a family of almost regular compact connected graphs.

  8. Lightweight composite fighting cover prototype development program

    Energy Technology Data Exchange (ETDEWEB)

    Wrenn, G.E. Jr.; Frame, B.J.; Gwaltney, R.C.; Akerman, M.A.


    The U.S. Army Field Assistance Science and Technology Program requested Oak Ridge National Laboratory (ORNL) to demonstrate the use of lightweight composite materials in construction of overhead covers for reinforced infantry fighting positions. In recent years, ORNL researchers have designed and tested several concepts for lightweight ballistic protection structures, and they have developed numerous prototype composite structures for military and civilian applications. In the current program, composite panel designs and materials are tested and optimized to meet anticipated static and dynamic load conditions for the overhead cover structure. Ten prototype composite covers were built at ORNL for use in Army field tests. Each composite cover has a nominal surface area of 12 ft[sup 2] and a nominal weight of 8 lb. Four of the prototypes are made with folding sections to improve their handling characteristics. The composite covers exhibit equivalent performance in Army field tests to covers made with conventional materials that weigh four times as much.

  9. Lightweight Service Oriented Architecture for Pervasive Computing

    CERN Document Server

    Tigli, Jean-Yves; Rey, Gaetan; Hourdin, Vincent; Riveill, Michel


    Pervasive computing appears like a new computing era based on networks of objects and devices evolving in a real world, radically different from distributed computing, based on networks of computers and data storages. Contrary to most context-aware approaches, we work on the assumption that pervasive software must be able to deal with a dynamic software environment before processing contextual data. After demonstrating that SOA (Service oriented Architecture) and its numerous principles are well adapted for pervasive computing, we present our extended SOA model for pervasive computing, called Service Lightweight Component Architecture (SLCA). SLCA presents various additional principles to meet completely pervasive software constraints: software infrastructure based on services for devices, local orchestrations based on lightweight component architecture and finally encapsulation of those orchestrations into composite services to address distributed composition of services. We present a sample application of t...

  10. Lightweight Protective Coatings For Titanium Alloys (United States)

    Wiedemann, Karl E.; Taylor, Patrick J.; Clark, Ronald K.


    Lightweight coating developed to protect titanium and titanium aluminide alloys and titanium-matrix composite materials from attack by environment when used at high temperatures. Applied by sol-gel methods, and thickness less than 5 micrometers. Reaction-barrier and self-healing diffusion-barrier layers combine to protect titanium alloy against chemical attack by oxygen and nitrogen at high temperatures with very promising results. Can be extended to protection of other environmentally sensitive materials.

  11. Southern Regional Center for Lightweight Innovative Design

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Paul T. [Mississippi State Univ., Mississippi State, MS (United States)


    The Southern Regional Center for Lightweight Innovative Design (SRCLID) has developed an experimentally validated cradle-to-grave modeling and simulation effort to optimize automotive components in order to decrease weight and cost, yet increase performance and safety in crash scenarios. In summary, the three major objectives of this project are accomplished: To develop experimentally validated cradle-to-grave modeling and simulation tools to optimize automotive and truck components for lightweighting materials (aluminum, steel, and Mg alloys and polymer-based composites) with consideration of uncertainty to decrease weight and cost, yet increase the performance and safety in impact scenarios; To develop multiscale computational models that quantify microstructure-property relations by evaluating various length scales, from the atomic through component levels, for each step of the manufacturing process for vehicles; and To develop an integrated K-12 educational program to educate students on lightweighting designs and impact scenarios. In this final report, we divided the content into two parts: the first part contains the development of building blocks for the project, including materials and process models, process-structure-property (PSP) relationship, and experimental validation capabilities; the second part presents the demonstration task for Mg front-end work associated with USAMP projects.

  12. Southern Regional Center for Lightweight Innovative Design

    Energy Technology Data Exchange (ETDEWEB)



    The Southern Regional Center for Lightweight Innovative Design (SRCLID) has developed an experimentally validated cradle-to-grave modeling and simulation effort to optimize automotive components in order to decrease weight and cost, yet increase performance and safety in crash scenarios. In summary, the three major objectives of this project are accomplished: To develop experimentally validated cradle-to-grave modeling and simulation tools to optimize automotive and truck components for lightweighting materials (aluminum, steel, and Mg alloys and polymer-based composites) with consideration of uncertainty to decrease weight and cost, yet increase the performance and safety in impact scenarios; To develop multiscale computational models that quantify microstructure-property relations by evaluating various length scales, from the atomic through component levels, for each step of the manufacturing process for vehicles; and To develop an integrated K-12 educational program to educate students on lightweighting designs and impact scenarios. In this final report, we divided the content into two parts: the first part contains the development of building blocks for the project, including materials and process models, process-structure-property (PSP) relationship, and experimental validation capabilities; the second part presents the demonstration task for Mg front-end work associated with USAMP projects.

  13. Compaction behavior of isomalt after roll compaction. (United States)

    Quodbach, Julian; Mosig, Johanna; Kleinebudde, Peter


    The suitability of the new isomalt grade galenIQ™ 801 for dry granulation and following tableting is evaluated in this study. Isomalt alone, as well as a blend of equal parts with dibasic calcium phosphate, is roll compacted and tableted. Particle size distribution and flowability of the granules and friability and disintegration time of the tablets are determined. Tensile strength of tablets is related to the specific compaction force during roll compaction and the tableting force. In all cases, the tensile strength increases with raising tableting forces. The specific compaction force has a different influence. For isomalt alone the tensile strength is highest for tablets made from granules prepared at 2 kN/cm and 6 kN/cm and decreases at higher values, i.e., >10 kN/cm. Tensile strength of the blend tablets is almost one third lower compared to the strongest tablets of pure isomalt. Friability of pure isomalt tablets is above the limit. Disintegration time is longest when the tensile strength is at its maximum and decreases with higher porosity and lower tensile strengths. Isomalt proves to be suitable for tableting after roll compaction. Even though the capacity as a binder might not be as high as of other excipients, it is a further alternative for the formulation scientist.

  14. Compaction Behavior of Isomalt after Roll Compaction

    Directory of Open Access Journals (Sweden)

    Peter Kleinebudde


    Full Text Available The suitability of the new isomalt grade galenIQ™ 801 for dry granulation and following tableting is evaluated in this study. Isomalt alone, as well as a blend of equal parts with dibasic calcium phosphate, is roll compacted and tableted. Particle size distribution and flowability of the granules and friability and disintegration time of the tablets are determined. Tensile strength of tablets is related to the specific compaction force during roll compaction and the tableting force. In all cases, the tensile strength increases with raising tableting forces. The specific compaction force has a different influence. For isomalt alone the tensile strength is highest for tablets made from granules prepared at 2 kN/cm and 6 kN/cm and decreases at higher values, i.e., >10 kN/cm. Tensile strength of the blend tablets is almost one third lower compared to the strongest tablets of pure isomalt. Friability of pure isomalt tablets is above the limit. Disintegration time is longest when the tensile strength is at its maximum and decreases with higher porosity and lower tensile strengths. Isomalt proves to be suitable for tableting after roll compaction. Even though the capacity as a binder might not be as high as of other excipients, it is a further alternative for the formulation scientist.

  15. Self-Compacting Concrete


    Okamura, Hajime; Ouchi, Masahiro


    Self-compacting concrete was first developed in 1988 to achieve durable concrete structures. Since then, various investigations have been carried out and this type of concrete has been used in practical structures in Japan, mainly by large construction companies. Investigations for establishing a rational mix-design method and self-compactability testing methods have been carried out from the viewpoint of making self-compacting concrete a standard concrete.

  16. Compact Polarimetry Potentials (United States)

    Truong-Loi, My-Linh; Dubois-Fernandez, Pascale; Pottier, Eric


    The goal of this study is to show the potential of a compact-pol SAR system for vegetation applications. Compact-pol concept has been suggested to minimize the system design while maximize the information and is declined as the ?/4, ?/2 and hybrid modes. In this paper, the applications such as biomass and vegetation height estimates are first presented, then, the equivalence between compact-pol data simulated from full-pol data and compact-pol data processed from raw data as such is shown. Finally, a calibration procedure using external targets is proposed.

  17. Compact Antenna Range (United States)

    Federal Laboratory Consortium — Facility consists of a folded compact antenna range including a computer controlled three axis position table, parabolic reflector and RF sources for the measurement...

  18. Mechanics of tissue compaction. (United States)

    Turlier, Hervé; Maître, Jean-Léon


    During embryonic development, tissues deform by a succession and combination of morphogenetic processes. Tissue compaction is the morphogenetic process by which a tissue adopts a tighter structure. Recent studies characterized the respective roles of cells' adhesive and contractile properties in tissue compaction. In this review, we formalize the mechanical and molecular principles of tissue compaction and we analyze through the prism of this framework several morphogenetic events: the compaction of the early mouse embryo, the formation of the fly retina, the segmentation of somites and the separation of germ layers during gastrulation.

  19. Design of ultra-lightweight concrete: towards monolithic concrete structures

    Directory of Open Access Journals (Sweden)

    Yu Qing Liang


    Full Text Available This study addresses the development of ultra-lightweight concrete. A moderate strength and an excellent thermal conductivity of the lightweight concrete are set as the design targets. The designed lightweight aggregates concrete is targeted to be used in monolithic concrete façade structure, performing as both load bearing element and thermal insulator. The developed lightweight concrete shows excellent thermal properties, with a low thermal conductivity of about 0.12 W/(m·K; and moderate mechanical properties, with 28-day compressive strengths of about 10-12 N/mm . This combination of values exceeds, to the researchers’ knowledge, the performance of all other lightweight building materials. Furthermore, the developed lightweight concrete possesses excellent durability properties.

  20. Laser Additive Manufacturing and Bionics: Redefining Lightweight Design (United States)

    Emmelmann, C.; Sander, P.; Kranz, J.; Wycisk, E.

    New layer wise manufacturing technologies such as Laser Additive Manufacturing (LAM) allow innovative approaches to product design. Especially for lightweight design in aircraft applications LAM offers new possibilities for load-adapted structures. However, to fully capture lightweight potential of LAM technologies new design guidelines and processes have to be developed. A novel approach to extreme lightweight design is realized by incorporating structural optimization tools, bionic structures and LAM guidelines into one design process. By consequently following this design process designers can achieve lightweight savings in designing new aircraft structures.

  1. Lightweight Thermally Stable Multi-Meter Aperture Submillimeter Reflectors Project (United States)

    National Aeronautics and Space Administration — Future astrophysics missions will require lightweight, thermally stable, submillimeter reflectors in sizes of 4m and greater. To date, graphite fiber reinforced...

  2. Lightweight Rubbery Aerogel Composites for High Performance Protection Project (United States)

    National Aeronautics and Space Administration — Aspen Aerogels Inc. (AAI) and the Man Vehicle Laboratory (MVL) at the Massachusetts Institute of Technology propose to develop nanostructured, lightweight, rubbery...

  3. Compaction properties of isomalt

    NARCIS (Netherlands)

    Bolhuis, Gerad K.; Engelhart, Jeffrey J. P.; Eissens, Anko C.


    Although other polyols have been described extensively as filler-binders in direct compaction of tablets, the polyol isomalt is rather unknown as pharmaceutical excipient, in spite of its description in all the main pharmacopoeias. In this paper the compaction properties of different types of ispoma

  4. Longbow: A Lightweight Remote Job Submission Tool

    Directory of Open Access Journals (Sweden)

    James Gebbie-Rayet


    Full Text Available We present Longbow, a lightweight console-based remote job submission tool and library. Longbow allows the user to quickly and simply run jobs on high performance computing facilities without leaving their familiar desktop environment. Not only does Longbow greatly simplify the management of compute- intensive jobs for experienced researchers, it also lowers the technical barriers surrounding high perfor-mance computation for the next generation of scientists and engineers. Longbow has already been used to remotely submit jobs in a number of projects and has the potential to redefine the manner in which high performance computers are used.

  5. Type Classes for Lightweight Substructural Types

    Directory of Open Access Journals (Sweden)

    Edward Gan


    Full Text Available Linear and substructural types are powerful tools, but adding them to standard functional programming languages often means introducing extra annotations and typing machinery. We propose a lightweight substructural type system design that recasts the structural rules of weakening and contraction as type classes; we demonstrate this design in a prototype language, Clamp. Clamp supports polymorphic substructural types as well as an expressive system of mutable references. At the same time, it adds little additional overhead to a standard Damas-Hindley-Milner type system enriched with type classes. We have established type safety for the core model and implemented a type checker with type inference in Haskell.

  6. Compaction properties of isomalt. (United States)

    Bolhuis, Gerad K; Engelhart, Jeffrey J P; Eissens, Anko C


    Although other polyols have been described extensively as filler-binders in direct compaction of tablets, the polyol isomalt is rather unknown as pharmaceutical excipient, in spite of its description in all the main pharmacopoeias. In this paper the compaction properties of different types of ispomalt were studied. The types used were the standard product sieved isomalt, milled isomalt and two types of agglomerated isomalt with a different ratio between 6-O-alpha-d-glucopyranosyl-d-sorbitol (GPS) and 1-O-alpha-d-glucopyranosyl-d-mannitol dihydrate (GPM). Powder flow properties, specific surface area and densities of the different types were investigated. Compactibility was investigated by compression of the tablets on a compaction simulator, simulating the compression on high-speed tabletting machines. Lubricant sensitivity was measured by compressing unlubricated tablets and tablets lubricated with 1% magnesium stearate on an instrumented hydraulic press. Sieved isomalt had excellent flow properties but the compactibility was found to be poor whereas the lubricant sensitivity was high. Milling resulted in both a strong increase in compactibility as an effect of the higher surface area for bonding and a decrease in lubricant sensitivity as an effect of the higher surface area to be coated with magnesium stearate. However, the flow properties of milled isomalt were too bad for use as filler-binder in direct compaction. Just as could be expected, agglomeration of milled isomalt by fluid bed agglomeration improved flowability. The good compaction properties and the low lubricant sensitivity were maintained. This effect is caused by an early fragmentation of the agglomerated material during the compaction process, producing clean, lubricant-free particles and a high surface for bonding. The different GPS/GPM ratios of the agglomerated isomalt types studied had no significant effect on the compaction properties.

  7. 76 FR 42137 - Certain Lightweight Thermal Paper From Germany; Remand Proceedings (United States)


    ... COMMISSION Certain Lightweight Thermal Paper From Germany; Remand Proceedings AGENCY: United States...-1127 concerning certain lightweight thermal paper (``LWTP'') from Germany. For further information... certain lightweight thermal paper from Germany that the Department of Commerce found were sold at...

  8. Advances in very lightweight composite mirror technology (United States)

    Chen, Peter C.; Bowers, Charles W.; Content, David A.; Marzouk, Marzouk; Romeo, Robert C.


    We report progress in the development of very lightweight (roll off and several waves (rms optical) of astigmatism, coma, and third-order spherical aberration. These are indications of thermal contraction in an inhomogeneous medium. This inhomogeneity is due to a systematic radial variation in density and fiber/resin ratio induced in composite plies when draped around a small and highly curved mandrel. The figure accuracy is expected to improve with larger size optics and in mirrors with longer radii of curvature. Nevertheless, the present accuracy figure is sufficient for using postfiguring techniques such as ion milling to achieve diffraction-limited performances at optical and UV wavelengths. We demonstrate active figure control using a simple apparatus of low-mass, low-force actuators to correct astigmatism. The optimized replication technique is applied to the fabrication of a 0.6-m-diam mirror with an areal density of 3.2 kg/m2. Our result demonstrates that the very lightweight, large-aperture construction used in radio telescopes can now be applied to optical telescopes.

  9. Lightweight design of automotive front crossbeam assembly

    Institute of Scientific and Technical Information of China (English)

    Yao Zaiqi; Liu Qiang; Ma Fangwu; Zhao Fuquan; Liu Zongwei; Wang Guan; Wan Yinhui; Li Luoxing


    This paper reviews the development course of the front crossbeam assembly for a self-owned brand vehicle model based on lightweight and passive safety performance. Combining with an A00 model variant, the paper details the design of extruded aluminum-alloy front crossbeam assembly from the perspectives of optimal design, performance verifi- cation, lightweight effect and cost control. The following results in the technical and engineering applications have been achieved. The weight of the developed aluminum-alloy crossbeam can be reduced by 51%. The simulated analysis of the collision rigid wall, the 40 % offset hammering as well as the static crush test of energy-absorbing box show that af- ter reasonable materials matching and size optimization of the crossbeam and the energy-absorbing boxes, the level of crash safety can be improved. The price of aluminum-alloy front crossbeam can be lowered by using the extruding die in- stead of the stamping die to reduce the die cost-sharing.

  10. FY2014 Lightweight Materials R&D Annual Progress Report

    Energy Technology Data Exchange (ETDEWEB)



    The Lightweight Materials research and development (R&D) area within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies under development. Research focuses on addressing critical barriers to commercializing lightweight materials for passenger and commercial vehicles.

  11. Testosterone and BMD in Elite Male Lightweight Rowers

    DEFF Research Database (Denmark)

    Vinther, A.; Christiansen, E.; Ekdahl, C.;


    The purpose of the present study was to investigate if a relationship between BMD and testosterone levels could be identified in elite male lightweight rowers. Thirteen male lightweight national team rowers had their BMD measured in a DEXA scanner. Plasma concentrations of total testosterone (TT)...

  12. Testosterone and BMD in elite male lightweight rowers

    DEFF Research Database (Denmark)

    Vinther, A; Kanstrup, I-L; Christiansen, E;


    The purpose of the present study was to investigate if a relationship between BMD and testosterone levels could be identified in elite male lightweight rowers. Thirteen male lightweight national team rowers had their BMD measured in a DEXA scanner. Plasma concentrations of total testosterone (TT)...

  13. Adaptive Backstepping Control of Lightweight Tower Wind Turbine

    DEFF Research Database (Denmark)

    Galeazzi, Roberto; Borup, Kasper Trolle; Niemann, Hans Henrik;


    This paper investigates the feasibility of operating a wind turbine with lightweight tower in the full load region exploiting an adaptive nonlinear controller that allows the turbine to dynamically lean against the wind while maintaining nominal power output. The use of lightweight structures...

  14. Anchorage of Main Reinforcement in Lightweight Aggregate Concrete Beams

    DEFF Research Database (Denmark)

    Larsen, Henning


    The paper deals with the anchorage of reinforcement bars at end supports in beam component made of lightweight aggregate concrete with open structure.......The paper deals with the anchorage of reinforcement bars at end supports in beam component made of lightweight aggregate concrete with open structure....

  15. Uncertainty and Variation of Vibration in Lightweight Structures

    DEFF Research Database (Denmark)

    Dickow, Kristoffer Ahrens


    Multi-family dwellings and offices build from lightweight materials are becoming a cost efficient and environmentally friendly alternative to traditional heavy structures.......Multi-family dwellings and offices build from lightweight materials are becoming a cost efficient and environmentally friendly alternative to traditional heavy structures....

  16. Small Valdivia compact spaces

    CERN Document Server

    Kubi's, W; Kubi\\'s, Wieslaw; Michalewski, Henryk


    We prove a preservation theorem for the class of Valdivia compact spaces, which involves inverse sequences of ``simple'' retractions. Consequently, a compact space of weight $\\loe\\aleph_1$ is Valdivia compact iff it is the limit of an inverse sequence of metric compacta whose bonding maps are retractions. As a corollary, we show that the class of Valdivia compacta of weight at most $\\aleph_1$ is preserved both under retractions and under open 0-dimensional images. Finally, we characterize the class of all Valdivia compacta in the language of category theory, which implies that this class is preserved under all continuous weight preserving functors.

  17. Lightweight Concrete Produced Using a Two-Stage Casting Process

    Directory of Open Access Journals (Sweden)

    Jin Young Yoon


    Full Text Available The type of lightweight aggregate and its volume fraction in a mix determine the density of lightweight concrete. Minimizing the density obviously requires a higher volume fraction, but this usually causes aggregates segregation in a conventional mixing process. This paper proposes a two-stage casting process to produce a lightweight concrete. This process involves placing lightweight aggregates in a frame and then filling in the remaining interstitial voids with cementitious grout. The casting process results in the lowest density of lightweight concrete, which consequently has low compressive strength. The irregularly shaped aggregates compensate for the weak point in terms of strength while the round-shape aggregates provide a strength of 20 MPa. Therefore, the proposed casting process can be applied for manufacturing non-structural elements and structural composites requiring a very low density and a strength of at most 20 MPa.

  18. Compact, Lightweight, Efficient Cooling Pump for Space Suit Life Support Systems Project (United States)

    National Aeronautics and Space Administration — With the increasing demands placed on extravehicular activity (EVA) for the International Space Station assembly and maintenance, along with planned lunar and...

  19. A Compact, Light-weight, Reliable and Highly Efficient Heat Pump for Space Applications Project (United States)

    National Aeronautics and Space Administration — Extra-vehicular activities (EVA) on the Moon and Mars will require suits with sophisticated thermal control systems allowing astronauts to work for extended periods...

  20. Compact microchannel system (United States)

    Griffiths, Stewart


    The present invention provides compact geometries for the layout of microchannel columns through the use of turns and straight channel segments. These compact geometries permit the use of long separation or reaction columns on a small microchannel substrate or, equivalently, permit columns of a fixed length to occupy a smaller substrate area. The new geometries are based in part on mathematical analyses that provide the minimum turn radius for which column performance in not degraded. In particular, we find that straight channel segments of sufficient length reduce the required minimum turn radius, enabling compact channel layout when turns and straight segments are combined. The compact geometries are obtained by using turns and straight segments in overlapped or nested arrangements to form pleated or coiled columns.

  1. Utilization of Bamboo as Lightweight Sandwich Panels

    Directory of Open Access Journals (Sweden)

    Suthon SRIVARO


    Full Text Available Lightweight sandwich panels consisting of bamboo faces and oil palm trunk core were manufactured using melamine urea formaldehyde with the resin content of 250 g/m2 (solid basis. The parameters examined were node and density of bamboo faces. Physical (board density, thickness swelling and water absorption and mechanical (modulus of elasticity and modulus of rupture properties of the sandwich board obtained were investigated and compared with other bamboo products and commercial wood based products. Result showed that this panel had better dimensional stability than those of other bamboo products but lower bending strength. Node of bamboo had no significant effect on any board properties examined. Most of board properties were influenced by bamboo face density. Comparing the properties to commercial wood based products, this panel could be used as wall/floor applications.

  2. Lightweight ceramic filter components: Evaluation and application

    Energy Technology Data Exchange (ETDEWEB)

    Eggerstedt, P.M.


    Ceramic candle filtration is an attractive technology for particulate removal at high temperatures. The primary objective of this SBIR research program is to increase the performance, durability, and corrosion resistance of lightweight filter candles and filter tubesheet components (Fibrosic{trademark}), fabricated from vacuum formed chopped ceramic fiber (VFCCF), for use in advanced coal utilization applications. Phase 1 results proved that significant gains in material strength and particle retentivity are possible by treatment of VFCCF materials with colloidal ceramic oxides. Phase 2 effort will show how these treated materials tolerate high temperature and vapor-phase alkali species, on a long-term basis. With good durability and corrosion resistance, high temperature capability, and a low installed and replacement cost, these novel materials will help promote commercial acceptance of ceramic candle filter technology, as well as increase the efficiency and reliability of coal utilization processes in general.

  3. Development of a lightweight fuel cell vehicle (United States)

    Hwang, J. J.; Wang, D. Y.; Shih, N. C.

    This paper described the development of a fuel cell system and its integration into the lightweight vehicle known as the Mingdao hydrogen vehicle (MHV). The fuel cell system consists of a 5-kW proton exchange membrane fuel cell (PEMFC), a microcontroller and other supported components like a compressed hydrogen cylinder, blower, solenoid valve, pressure regulator, water pump, heat exchanger and sensors. The fuel cell not only propels the vehicle but also powers the supporting components. The MHV performs satisfactorily over a hundred-kilometer drive thus validating the concept of a fuel cell powered zero-emission vehicle. Measurements further show that the fuel cell system has an efficiency of over 30% at the power consumption for vehicle cruise, which is higher than that of a typical internal combustion engine. Tests to improve performance such as speed enhancement, acceleration and fuel efficiency will be conducted in the future work. Such tests will consist of hybridizing with a battery pack.

  4. Lightweight, low-cost solar energy collector (United States)

    Hochberg, Eric B. (Inventor); Costen, Michael K. (Inventor)


    A lightweight solar concentrator of the reflecting parabolic or trough type is realized via a thin reflecting film, an inflatable structural housing and tensioned fibers. The reflector element itself is a thin, flexible, specularly-reflecting sheet or film. The film is maintained in the parabolic trough shape by means of a plurality of identical tensioned fibers arranged to be parallel to the longitudinal axis of the parabola. Fiber ends are terminated in two identical spaced anchorplates, each containing a plurality of holes which lie on the desired parabolic contour. In a preferred embodiment, these fibers are arrayed in pairs with one fiber contacting the front side of the reflecting film and the other contacting the back side of the reflecting film. The reflective surface is thereby slidably captured between arrays of fibers which control the shape and position of the reflective film. Gas pressure in the inflatable housing generates fiber tension to achieve a truer parabolic shape.

  5. Advanced casting technologies for lightweight automotive applications

    Directory of Open Access Journals (Sweden)

    Alan A. Luo


    Full Text Available This paper provides an overview of alloy and process developments in aluminum and magnesium castings for lightweight automotive applications. Wear-resistant aluminum alloys, creep-resistant and high strength/ductility magnesium alloys have been developed for automotive applications. On the process front, vacuum-assisted die casting and high vacuum die casting technologies have been developed for high-integrity body and chassis applications. Thin-wall and hollow casting components are being produced by low-pressure die casting processes for structural applications. Overcasting technology is gaining traction and has enabled mixed material designs for automotive sub-systems such as engine cradles and instrument panel beams. Simulation tools developed to predict the interfacial interactions of the dissimilar components and the structural integrity of the overcast systems are being validated in the casting trials.

  6. Lightweight males of Podisus nigrispinus (Heteroptera: Pentatomidae neglect lightweight females due low reproductive fitness

    Directory of Open Access Journals (Sweden)

    A. I. A. Pereira

    Full Text Available Abstract Sexual choice by male stink bugs is important because females that experience food shortages lay fewer eggs with lower viability compared with well-fed females. In this study, we investigated whether Podisus nigrispinus (Dallas (Heteroptera: Pentatomidae males fed with a low-quality diet during its nymphal stage show selectivity for sexual partners resulting in high-quality progeny. Lightweight males and females were obtained from nymphs fed weekly with Tenebrio molitor L. (Coleoptera: Tenebrionidae pupae. By contrast, heavyweight males and females were fed three times a week and received an extra nutritional source: cotton leaves, Gossypium hirsutum L. (Malvaceae. Lightweight males preferred to mate with heavy females (77.78 ± 14.69%, whereas heavyweight males did not discriminated between light or heavyweight females. Females mated with lightweight males showed similar levels of reproduction to those mated with heavyweight males. The results provide an indication of the importance of male and female body weight for sexual selection in Asopinae stink bugs.

  7. Vehicular hydrogen storage using lightweight tanks

    Energy Technology Data Exchange (ETDEWEB)

    Mitlitsky, F; Weisberg, A H; Myers, B


    Lightweight hydrogen storage for vehicles is enabled by adopting and adapting aerospace tankage technology. The weight, volume, and cost are already acceptable and improving. Prototype tankage was demonstrated with 11.3% hydrogen by weight, 1.74 million inch (44.3 km) burst performance factor (P{sub b}V/W), and 3.77 kWh/kg specific energy for the tank and hydrogen (LHV). DOE cannot afford full scale aerospace development costs. For example, it costs many tens of $M to develop a rocket motor casing with a safety factor (SF) of 1.25. Large teams of experts are required to design, develop, and test new processes. Car companies are buying existing technology with only modest investments in research and development (R&D). The Lawrence Livermore National Laboratory (LLNL) team is maximizing the leverage from DOE funding by joining with industry to solve technical risks at the component level. LLNL is developing fabrication processes with IMPCO Technologies, Thiokol Propulsion, and Aero Tec Laboratories (ATL). LLNL is creating commercial products that are close to adoption under DOE solicitation. LLNL is breaking ground to achieve greater than 10% hydrogen by weight tankage with safety that exceeds the requirements of NGV2 standards modified for hydrogen. Risk reduction is proceeding along three axes: (1) Commercializable products will be available next year with {approx}90% confidence; (2) R&D progress is pushing the envelope in lightweight tankage for vehicles; and (3) Integration challenges are being met with partners in industry and DOE demo programs. This project is a key part of LLNL's effort to develop high cycle life energy storage systems with >600 Wh/kg specific energy for various applications, including: high altitude long endurance solar rechargeable aircraft, zero emission vehicles, hybrid energy storage/propulsion systems for spacecraft, energy storage for premium power, remote power sources, and peak shaving.

  8. Lightweight MIPv6 with IPSec Support

    Directory of Open Access Journals (Sweden)

    Antonio J. Jara


    Full Text Available Mobility management is a desired feature for the emerging Internet of Things (IoT. Mobility aware solutions increase the connectivity and enhance adaptability to changes of the location and infrastructure. IoT is enabling a new generation of dynamic ecosystems in environments such as smart cities and hospitals. Dynamic ecosystems require ubiquitous access to Internet, seamless handover, flexible roaming policies, and an interoperable mobility protocol with existing Internet infrastructure. These features are challenges for IoT devices, which are usually constrained devices with low memory, processing, communication and energy capabilities. This work presents an analysis of the requirements and desirable features for the mobility support in the IoT, and proposes an efficient solution for constrained environments based on Mobile IPv6 and IPSec. Compatibility with IPv6-existing protocols has been considered a major requirement in order to offer scalable and inter-domain solutions that were not limited to specific application domains in order to enable a new generation of application and services over Internet-enabled dynamic ecosystems, and security support based on IPSec has been also considered, since dynamic ecosystems present several challenges in terms of security and privacy. This work has, on the one hand, analysed suitability of Mobile IPv6 and IPSec for constrained devices, and on the other hand, analysed, designed, developed and evaluated a lightweight version of Mobile IPv6 and IPSec. The proposed solution of lightweight Mobile IPv6 with IPSec is aware of the requirements of the IoT and presents the best solution for dynamic ecosystems in terms of efficiency and security adapted to IoT-devices capabilities. This presents concerns in terms of higher overhead and memory requirements. But, it is proofed and concluded that even when higher memory is required and major overhead is presented, the integration of Mobile IPv6 and IPSec for

  9. Frequency stability of a tunable diode laser mounted in a compact Stirling cycle cooler (United States)

    Durso, Santo S.; May, R. D.; Tuchscherer, M. A.; Webster, C. R.


    A tunable diode laser (TDL) has been operated with a compact lightweight closed-cycle Stirling cooler. The laser linewidth has been measured near 80 K and found to be about half of that when using more massive closed-cycle coolers. Novel applications include balloon-borne and aircraft-adapted instruments, where size, weight, and power requirements place stringent demands on necessary TDL cooling systems.

  10. Plasma-enhanced gasification of low-grade coals for compact power plants (United States)

    Uhm, Han S.; Hong, Yong C.; Shin, Dong H.; Lee, Bong J.


    A high temperature of a steam torch ensures an efficient gasification of low-grade coals, which is comparable to that of high-grade coals. Therefore, the coal gasification system energized by microwaves can serve as a moderately sized power plant due to its compact and lightweight design. This plasma power plant of low-grade coals would be useful in rural or sparsely populated areas without access to a national power grid.

  11. Ultra-Lightweight Self-Deployable Nanocomposite Structure for Habitat Applications (United States)

    Tan, Seng C.


    A document discusses self-deployable, rigidized structures that are ultra-lightweight and have gas barrier properties, space durability, and high impact resistance. Developed here are microcellular-foamed sandwich structures made from nanocomposite shape memory polymers (SMPs) with Cold-Hibernated Elastic Memory (CHEM) deployed technique for space structural components including space habitats. This type of foam sandwich also does not suffer from the toxicity problems of conventional foams, and has higher mechanical properties than those processed with conventional techniques. This design can be compacted into a very small volume for launch. Once deployed, the microcellular structure can use the heat from the Sun to recover 98 to 100 percent of its shape.

  12. Effect of lightweight aggregate intrinsic Strength on lightweight concrete compressive strength and modulus of elasticity

    Directory of Open Access Journals (Sweden)

    Videla, C.


    Full Text Available The study of Structural Lightweight Concrete (SLC, which is a material generally composed of cement, water and lightweight aggregate, has been mainly focused on developing particular cases. Then, the main objective of this research was to generalise the knowledge of this type of material. Particularly, the effect of replacing conventional coarse aggregate by lightweight aggregate on mechanical properties of concrete was studied. SLC may be conceived as a two -phase material. The first phase, composed of cement, water and siliceous natural sand, is called the "resistant phase", and contributes to the structural strength. The second phase is the lightweight phase, comprised of coarse lightweight aggregate, and it is meant to decrease the concrete density. In this way it would be possible to describe the mechanical behaviour of concrete, based on lightweight aggregate and the cement mortar parameters. The obtained results allow for the proposition of relationships between mechanical properties of SLC (such as compressive strength and modulus of elasticity and the constituent materials properties and amount. At the same time, an easily measured index representing the structural capability of lightweight aggregate is also proposed, this index allows to estimate the potential mechanical properties of concrete which could be obtained by using a particular aggregate.

    El estudio del Hormigón Ligero Estructural (HLE, material compuesto generalmente por cemento, agua y árido ligero, ha estado enfocado principalmente al desarrollo de casos particulares. Por lo anterior, el objetivo principal de esta investigación fue generalizar el conocimiento sobre este material. En particular, la meta de este trabajo fue estudiar el efecto que tiene el reemplazo de árido convencional por un árido ligero, en las propiedades mecánicas del hormigón. El modelo aplicado conceptualiza al HLE como un material de dos fases, una denominada "soportante", constituida

  13. Integrated Control with Structural Feedback to Enable Lightweight Aircraft (United States)

    Taylor, Brian R.


    This presentation for the Fundamental Aeronautics Program Technical Conference covers the benefits of active structural control, related research areas, and focuses on the use of optimal control allocation for the prevention of critical loads. Active control of lightweight structures has the potential to reduce aircraft weight and fuel burn. Sensor, control law, materials, control effector, and system level research will be necessary to enable active control of lightweight structures. Optimal control allocation with structural feedback has been shown in simulation to be feasible in preventing critical loads and is one example of a control law to enable future lightweight aircraft.

  14. Compactness theorems of fuzzy semantics

    Institute of Scientific and Technical Information of China (English)


    The relationship among diverse fuzzy semantics vs. the corresponding logic consequence operators has been analyzed systematically. The results that compactness and logical compactness of fuzzy semantics are equivalent to compactness and continuity of the logic consequence operator induced by the semantics respectively have been proved under certain conditions. A general compactness theorem of fuzzy semantics have been established which says that every fuzzy semantics defined on a free algebra with members corresponding to continuous functions is compact.

  15. Intelligent compaction theory of high roller compacted concrete dam

    Institute of Scientific and Technical Information of China (English)

    Liu Donghai


    The concept and realization process of intelligent compaction for the construction of high roller compacted concrete dam were presented, as well as the theory of monitoring and intelligent feedback control. Based on the real-time analysis of the compaction index, a multiple regression model of the dam compactness was established and a realime estimation method of compaction quality for the entire work area of roller compacted concrete dam was proposed finally. The adaptive adjustment of the roiling process parameters was achieved, with the speed, the exciting force, the roller pass and the compaction thickness meeting the standards during the whole construction process. As a result, the compaction quality and construction efficiency can be improved. The research provides a new way for the construction quality control of roller compacted concrete dam.

  16. Low Cost, Lightweight, Multifunctional Structural Shielding Materials Project (United States)

    National Aeronautics and Space Administration — This SBIR involves the development of a lightweight innovative material for use as structure and radiation shielding in one. APS has assembled a uniquely qualified...

  17. Lightweight IMM Multi-Junction Photovoltaic Flexible Blanket Assembly Project (United States)

    National Aeronautics and Space Administration — Deployable Space Systems (DSS) and EMCORE as a key subcontractor will focus the proposed SBIR program on the creation and optimization of a lightweight ~33%...

  18. Next Generation MK III Lightweight HUT/Hatch Assembly Project (United States)

    National Aeronautics and Space Administration — A prototype Next Generation MK III Lightweight HUT/Hatch Assembly will be fabricated and delivered during Phase II. Maximum weight reduction for the Hard Upper...

  19. Ultra-Lightweight Large Aperture Support Structures Project (United States)

    National Aeronautics and Space Administration — Ultra-lightweight membranes may prove to be very attractive for large aperture systems, but their value will be fully realized only if they are mated with equally...

  20. Next Generation MK III Lightweight HUT/Hatch Assembly Project (United States)

    National Aeronautics and Space Administration — The Next Generation MK III Lightweight HUT/Hatch Assembly will maximize the Hard Upper Torso - Hatch assembly weight reduction through the combination of innovative...

  1. Lightweight InP Solar Cells for Space Applications Project (United States)

    National Aeronautics and Space Administration — The innovation in this Phase II SBIR is the development of a technology which will enable the manufacture of a lightweight, low cost, high radiation resistance InP...

  2. Lightweight Metal RubberTM Sensors and Interconnects Project (United States)

    National Aeronautics and Space Administration — The objective of the proposed program is to develop lightweight and highly elastic electrically conducting interconnects and strain sensor arrays for next generation...

  3. Lightweight landscape enhancing design through minimal mass structures

    CERN Document Server

    Spinelli, Luigi; Monticelli, Carol; Pedrali, Paolo


    This book explains how lightweight materials and structures can be deployed in buildings to meet high environmental and aesthetic standards and emphasizes how the concept of lightness in building technology and design dovetails with the desire to enhance landscape. The first part of the book, on lightweight construction, aims to foster the use of membranes within the specific climatic context and in particular considers how lightweight materials and innovative technologies can enrich the quality of temporary spaces. The second part focuses exclusively on landscape, presenting novel approaches in the search for visual lightness and the quest to improve urban spaces. Particular attention is paid to the Italian experience, where the traditional appreciation of brick and stone has limited the scope for use of lightweight structures and membrane materials, often relegating them to a secondary or inappropriate role. The reader will come to appreciate how this attitude demeans a very advanced productive sector and n...

  4. Lightweight InP Solar Cells for Space Applications Project (United States)

    National Aeronautics and Space Administration — The innovation in this Phase I SBIR is the development of a technology which will enable the manufacture of a lightweight, low cost, InP based compound semiconductor...

  5. Lightweight Aggregate Concrete Beams. Load-bearing Capacity

    DEFF Research Database (Denmark)

    Larsen, Henning; Goltermann, Per; Ingholt, N.U.


    This paper deals with the load-bearing capacity of reinforced beams made of lightweight aggregate concrete with open structure and documents formulas for the moment capacity as well as the shear force capacity.......This paper deals with the load-bearing capacity of reinforced beams made of lightweight aggregate concrete with open structure and documents formulas for the moment capacity as well as the shear force capacity....

  6. Lightweight Aggregate Concrete Components. Load-bearing Capacity

    DEFF Research Database (Denmark)

    Larsen, Henning; Ingholt, N.U.; Goltermann, Per


    The project presented here deals with the load-bearing capacity of reinforced beams made of lightweight aggregate concrete with open structure and documents expressions for the moment capacity as well as the shear force capacity......The project presented here deals with the load-bearing capacity of reinforced beams made of lightweight aggregate concrete with open structure and documents expressions for the moment capacity as well as the shear force capacity...

  7. Study on Performance and Processability of Sirofil Lightweight Worsted Fabric

    Institute of Scientific and Technical Information of China (English)

    李明菊; 范德炘; 葛惠萍; 侯祖龄


    The lightweight worsted fabric made of Sirofil yarn was developed and its textile performance was studied. By means of conventional testing, KES and FAST, it is concluded that with the coordination of proper fabric design and processing technique, the performance of this innovative fabric is superior to that of the conventional lightweight fabric Furthermore, it is predicted from the relevant parameters that its processability in the following suit manufacture is very desirable.


    Energy Technology Data Exchange (ETDEWEB)

    Vas Choudhry; Stephen Kwan; Steven R. Hadley


    The objective of the project entitled ''Utilization of Lightweight Materials Made from Coal Gasification Slags'' was to demonstrate the technical and economic viability of manufacturing low-unit-weight products from coal gasification slags which can be used as substitutes for conventional lightweight and ultra-lightweight aggregates. In Phase I, the technology developed by Praxis to produce lightweight aggregates from slag (termed SLA) was applied to produce a large batch (10 tons) of expanded slag using pilot direct-fired rotary kilns and a fluidized bed calciner. The expanded products were characterized using basic characterization and application-oriented tests. Phase II involved the demonstration and evaluation of the use of expanded slag aggregates to produce a number of end-use applications including lightweight roof tiles, lightweight precast products (e.g., masonry blocks), structural concrete, insulating concrete, loose fill insulation, and as a substitute for expanded perlite and vermiculite in horticultural applications. Prototypes of these end-use applications were made and tested with the assistance of commercial manufacturers. Finally, the economics of expanded slag production was determined and compared with the alternative of slag disposal. Production of value-added products from SLA has a significant potential to enhance the overall gasification process economics, especially when the avoided costs of disposal are considered.

  9. Advanced steel body concepts for automotive lightweight design

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, H.G. [DaimlerChrysler AG, Stuttgart (Germany). Research Body and Powertrain


    Lightweight design is a must for future vehicle concepts due to the self-commitment on the reduction of fleet consumption. Body concepts for mid- and high-volume vehicles demand smart lightweight solutions without increasing costs and without sacrificing the high level of safety (e.g. future passive safety standards). Furthermore, all lightweight activities have to comply with requirements in terms of reliability (no additional efforts for maintenance), NVH (no additional weight for e.g. damping) and future stricter recycling quotas. Successful lightweight design solutions are determined by the best relation between weight-saving and additional costs as a function of the annual production volume. Using advanced high-strength steels (TWIP-steels) seems to be a very promising approach for cost-optimized lightweight design of body structures. In addition, by applying bionic optimization, the weight of body-structures can be significantly reduced. As a consequence, only a holistic approach for lightweight design combining the three areas materials, design and manufacturing is needed in order to use the full potential of cost-optimized weight-reduction. (orig.)

  10. Limestone compaction: an enigma (United States)

    Shinn, Eugene A.; Halley, Robert B.; Hudson, J. Harold; Lidz, Barbara H.


    Compression of an undisturbed carbonate sediment core under a pressure of 556 kg/cm2 produced a “rock” with sedimentary structures similar to typical ancient fine-grained limestones. Surprisingly, shells, foraminifera, and other fossils were not noticeably crushed, which indicates that absence of crushed fossils in ancient limestones can no longer be considered evidence that limestones do not compact.

  11. Abstracting audit data for lightweight intrusion detection

    KAUST Repository

    Wang, Wei


    High speed of processing massive audit data is crucial for an anomaly Intrusion Detection System (IDS) to achieve real-time performance during the detection. Abstracting audit data is a potential solution to improve the efficiency of data processing. In this work, we propose two strategies of data abstraction in order to build a lightweight detection model. The first strategy is exemplar extraction and the second is attribute abstraction. Two clustering algorithms, Affinity Propagation (AP) as well as traditional k-means, are employed to extract the exemplars, and Principal Component Analysis (PCA) is employed to abstract important attributes (a.k.a. features) from the audit data. Real HTTP traffic data collected in our institute as well as KDD 1999 data are used to validate the two strategies of data abstraction. The extensive test results show that the process of exemplar extraction significantly improves the detection efficiency and has a better detection performance than PCA in data abstraction. © 2010 Springer-Verlag.

  12. Lightweight Solar Power for Small Satellites (United States)

    Nabors, Sammy A.


    The innovation targets small satellites or CubeSats for which conventional deployable arrays are not feasible due to their size, weight and complexity. This novel solar cell array includes a thin and flexible photovoltaic cell applied to an inflatable structure to create a high surface area array for collecting solar energy in a lightweight, simple and deployable structure. The inflatable array, with its high functional surface area, eliminates the need and the mechanisms required to point the system toward the sun. The power density achievable in these small arrays is similar to that of conventional high-power deployable/pointable arrays used on large satellites or space vehicles. Although inflatable solar arrays have been previously considered by others, the arrays involved the use of traditional rigid solar cells. Researchers are currently working with thin film photovoltaics from various suppliers so that the NASA innovation is not limited to any particular solar cell technology. NASA has built prototypes and tested functionality before and after inflation. As shown in the current-voltage currents below, deployment does not damage the cell performance.

  13. Parallel Array Classes and Lightweight Sharing Mechanisms

    Directory of Open Access Journals (Sweden)

    Steve W. Otto


    Full Text Available We discuss a set of parallel array classes, MetaMP, for distributed-memory architectures. The classes are implemented in C++ and interface to the PVM or Intel NX message-passing systems. An array class implements a partitioned array as a set of objects distributed across the nodes – a "collective" object. Object methods hide the low-level message-passing and implement meaningful array operations. These include transparent guard strips (or sharing regions that support finite-difference stencils, reductions and multibroadcasts for support of pivoting and row operations, and interpolation/contraction operations for support of multigrid algorithms. The concept of guard strips is generalized to an object implementation of lightweight sharing mechanisms for finite element method (FEM and particle-in-cell (PIC algorithms. The sharing is accomplished through the mechanism of weak memory coherence and can be efficiently implemented. The price of the efficient implementation is memory usage and the need to explicitly specify the coherence operations. An intriguing feature of this programming model is that it maps well to both distributed-memory and shared-memory architectures.

  14. Chlorinated drinking water for lightweight laying hens

    Directory of Open Access Journals (Sweden)

    A.F. Schneider

    Full Text Available ABSTRACT The study aimed to evaluate the effect of different levels of chlorine in drinking water of laying hens on zootechnical performance, eggs shell quality, hemogasometry levels and calcium content in tibia. 144 Hy-Line laying hens, 61 weeks old, were used distributed in 24 metabolism cages. They were subjected to water diets, for a period of 28 days, using sodium hypochlorite as a chlorine source in order to obtain the following concentrations: 5ppm (control, 20ppm, 50ppm, and 100ppm. Their performance was evaluated through water consumption, feed intake, egg production and weight, egg mass, feed conversion. Shell quality was measured by specific gravity. At the end of the experiment, arterial blood was collected for blood gas level assessment and a poultry of each replicate was sacrificed to obtain tibia and calcium content measurement. There was a water consumption reduction from 20ppm of chlorine and feed intake reduction in poultry receiving water with 100ppm of chlorine. The regression analysis showed that the higher the level of chlorine in water, the higher the reduction in consumption. There were no differences in egg production and weight, egg mass, feed conversion, specific gravity, tibia calcium content, and hemogasometry levels (hydrogenionic potential, carbon dioxide partial pressure, oxygen partial pressure, sodium, potassium, chloride, bicarbonate, carbon dioxide total concentration, anion gap and oxygen saturation. The use of levels above 5ppm of chlorine is not recommended in the water of lightweight laying hens.

  15. Lightweight autonomous chemical identification system (LACIS) (United States)

    Lozos, George; Lin, Hai; Burch, Timothy


    Smiths Detection and Intelligent Optical Systems have developed prototypes for the Lightweight Autonomous Chemical Identification System (LACIS) for the US Department of Homeland Security. LACIS is to be a handheld detection system for Chemical Warfare Agents (CWAs) and Toxic Industrial Chemicals (TICs). LACIS is designed to have a low limit of detection and rapid response time for use by emergency responders and could allow determination of areas having dangerous concentration levels and if protective garments will be required. Procedures for protection of responders from hazardous materials incidents require the use of protective equipment until such time as the hazard can be assessed. Such accurate analysis can accelerate operations and increase effectiveness. LACIS is to be an improved point detector employing novel CBRNE detection modalities that includes a militaryproven ruggedized ion mobility spectrometer (IMS) with an array of electro-resistive sensors to extend the range of chemical threats detected in a single device. It uses a novel sensor data fusion and threat classification architecture to interpret the independent sensor responses and provide robust detection at low levels in complex backgrounds with minimal false alarms. The performance of LACIS prototypes have been characterized in independent third party laboratory tests at the Battelle Memorial Institute (BMI, Columbus, OH) and indoor and outdoor field tests at the Nevada National Security Site (NNSS). LACIS prototypes will be entering operational assessment by key government emergency response groups to determine its capabilities versus requirements.

  16. Lightweight Thermoformed Structural Components and Optics (United States)

    Zeiders, Glenn W.; Bradford, Larry J.


    A technique that involves the use of thermoformed plastics has been developed to enable the design and fabrication of ultra-lightweight structural components and mirrors for use in outer space. The technique could also be used to produce items for special terrestrial uses in which minimization of weight is a primary design consideration. Although the inherent strengths of thermoplastics are clearly inferior to those of metals and composite materials, thermoplastics offer a distinct advantage in that they can be shaped, at elevated temperatures, to replicate surfaces (e.g., prescribed mirror surfaces) precisely. Furthermore, multiple elements can be bonded into structures of homogeneous design that display minimal thermal deformation aside from simple expansion. The design aspect of the present technique is based on the principle that the deflection of a plate that has internal structure depends far more on the overall thickness than on the internal details; thus, a very stiff, light structure can be made from thin plastic that is heatformed to produce a sufficiently high moment of inertia. General examples of such structures include I beams and eggcrates.

  17. Testnodes: a Lightweight Node-Testing Infrastructure (United States)

    Fay, R.; Bland, J.


    A key aspect of ensuring optimum cluster reliability and productivity lies in keeping worker nodes in a healthy state. Testnodes is a lightweight node testing solution developed at Liverpool. While Nagios has been used locally for general monitoring of hosts and services, Testnodes is optimised to answer one question: is there any reason this node should not be accepting jobs? This tight focus enables Testnodes to inspect nodes frequently with minimal impact and provide a comprehensive and easily extended check with each inspection. On the server side, Testnodes, implemented in python, interoperates with the Torque batch server to control the nodes production status. Testnodes remotely and in parallel executes client-side test scripts and processes the return codes and output, adjusting the node's online/offline status accordingly to preserve the integrity of the overall batch system. Testnodes reports via log, email and Nagios, allowing a quick overview of node status to be reviewed and specific node issues to be identified and resolved quickly. This presentation will cover testnodes design and implementation, together with the results of its use in production at Liverpool, and future development plans.

  18. Improving the compaction properties of roller compacted calcium carbonate. (United States)

    Bacher, C; Olsen, P M; Bertelsen, P; Kristensen, J; Sonnergaard, J M


    The effects of roller compaction process parameters, morphological forms of calcium carbonate and particle size of sorbitol on flow, compaction and compression properties were investigated. The morphology of the calcium carbonate and the sorbitol particle size were more influential on the compaction properties than the settings of the roller compactor. The roller compaction process was demonstrated to be robust and stable in regard to flowability and compactibility. The flowability of the granules was improved adequately to facilitate compression in a production scale rotary tablet press. By adding sorbitol to the calcium carbonate, the compressibility - characterized by the Walker coefficient W(ID) - and the compactibility C(P) were improved considerably. A correlation between the consolidation characteristics was demonstrated. Compactibility data from the compaction simulator correlated with the tablet press for two of the calcium carbonates, the cubic form and the ground quality.

  19. Progress in Compact Toroid Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Dolan, Thomas James


    The term "compact toroids" as used here means spherical tokamaks, spheromaks, and field reversed configurations, but not reversed field pinches. There are about 17 compact toroid experiments under construction or operating, with approximate parameters listed in Table 1.

  20. Towards establishing compact imaging spectrometer standards (United States)

    Slonecker, E. Terrence; Allen, David W.; Resmini, Ronald G.


    Remote sensing science is currently undergoing a tremendous expansion in the area of hyperspectral imaging (HSI) technology. Spurred largely by the explosive growth of Unmanned Aerial Vehicles (UAV), sometimes called Unmanned Aircraft Systems (UAS), or drones, HSI capabilities that once required access to one of only a handful of very specialized and expensive sensor systems are now miniaturized and widely available commercially. Small compact imaging spectrometers (CIS) now on the market offer a number of hyperspectral imaging capabilities in terms of spectral range and sampling. The potential uses of HSI/CIS on UAVs/UASs seem limitless. However, the rapid expansion of unmanned aircraft and small hyperspectral sensor capabilities has created a number of questions related to technological, legal, and operational capabilities. Lightweight sensor systems suitable for UAV platforms are being advertised in the trade literature at an ever-expanding rate with no standardization of system performance specifications or terms of reference. To address this issue, both the U.S. Geological Survey and the National Institute of Standards and Technology are eveloping draft standards to meet these issues. This paper presents the outline of a combined USGS/NIST cooperative strategy to develop and test a characterization methodology to meet the needs of a new and expanding UAV/CIS/HSI user community.


    Directory of Open Access Journals (Sweden)

    Budi Darma Laksana


    Full Text Available In this paper, a light-weight MVC framework for smart device application is designed and implemented. The primary goal of the work is to provide a MVC framework for a commercial smart device product development. To this end, the developed framework presents integration between the classic design patterns, MVC and state-of-the-art technology XAML by adapting a MVC framework of an open source XAML efforts, MyXaml into .NET Compact Framework. As the compact framework only comprises 12% of .NET Framework library, some design and architectural changes of the existing framework need to be done to achieve the same abstraction level. The adapted framework enables to reduce the complexity of the smart device application development, reuse each component of the MVC separately in different project and provide a more manageable source code as the system architecture is more apparent from the source code itself as well as provide a commonality of the development pattern. A prototype of simple database interface application was built to show these benefits.

  2. Characterization of Polyimide Foams for Ultra-Lightweight Space Structures (United States)

    Meador, Michael (Technical Monitor); Hillman, Keithan; Veazie, David R.


    Ultra-lightweight materials have played a significant role in nearly every area of human activity ranging from magnetic tapes and artificial organs to atmospheric balloons and space inflatables. The application range of ultra-lightweight materials in past decades has expanded dramatically due to their unsurpassed efficiency in terms of low weight and high compliance properties. A new generation of ultra-lightweight materials involving advanced polymeric materials, such as TEEK (TM) polyimide foams, is beginning to emerge to produce novel performance from ultra-lightweight systems for space applications. As a result, they require that special conditions be fulfilled to ensure adequate structural performance, shape retention, and thermal stability. It is therefore important and essential to develop methodologies for predicting the complex properties of ultra-lightweight foams. To support NASA programs such as the Reusable Launch Vehicle (RLV), Clark Atlanta University, along with SORDAL, Inc., has initiated projects for commercial process development of polyimide foams for the proposed cryogenic tank integrated structure (see figure 1). Fabrication and characterization of high temperature, advanced aerospace-grade polyimide foams and filled foam sandwich composites for specified lifetimes in NASA space applications, as well as quantifying the lifetime of components, are immensely attractive goals. In order to improve the development, durability, safety, and life cycle performance of ultra-lightweight polymeric foams, test methods for the properties are constant concerns in terms of timeliness, reliability, and cost. A major challenge is to identify the mechanisms of failures (i.e., core failure, interfacial debonding, and crack development) that are reflected in the measured properties. The long-term goal of the this research is to develop the tools and capabilities necessary to successfully engineer ultra-lightweight polymeric foams. The desire is to reduce density

  3. Next Generation Lightweight Mirror Modeling Software (United States)

    Arnold, William R., Sr.; Fitzgerald, Mathew; Rosa, Rubin Jaca; Stahl, H. Philip


    The advances in manufacturing techniques for lightweight mirrors, such as EXELSIS deep core low temperature fusion, Corning's continued improvements in the Frit bonding process and the ability to cast large complex designs, combined with water-jet and conventional diamond machining of glasses and ceramics has created the need for more efficient means of generating finite element models of these structures. Traditional methods of assembling 400,000 + element models can take weeks of effort, severely limiting the range of possible optimization variables. This paper will introduce model generation software developed under NASA sponsorship for the design of both terrestrial and space based mirrors. The software deals with any current mirror manufacturing technique, single substrates, multiple arrays of substrates, as well as the ability to merge submodels into a single large model. The modeler generates both mirror and suspension system elements, suspensions can be created either for each individual petal or the whole mirror. A typical model generation of 250,000 nodes and 450,000 elements only takes 5-10 minutes, much of that time being variable input time. The program can create input decks for ANSYS, ABAQUS and NASTRAN. An archive/retrieval system permits creation of complete trade studies, varying cell size, depth, and petal size, suspension geometry with the ability to recall a particular set of parameters and make small or large changes with ease. The input decks created by the modeler are text files which can be modified by any editor, all the key shell thickness parameters are accessible and comments in deck identify which groups of elements are associated with these parameters. This again makes optimization easier. With ANSYS decks, the nodes representing support attachments are grouped into components; in ABAQUS these are SETS and in NASTRAN as GRIDPOINT SETS, this make integration of these models into large telescope or satellite models easier.

  4. Next-Generation Lightweight Mirror Modeling Software (United States)

    Arnold, William R., Sr.; Fitzgerald, Mathew; Rosa, Rubin Jaca; Stahl, Phil


    The advances in manufacturing techniques for lightweight mirrors, such as EXELSIS deep core low temperature fusion, Corning's continued improvements in the Frit bonding process and the ability to cast large complex designs, combined with water-jet and conventional diamond machining of glasses and ceramics has created the need for more efficient means of generating finite element models of these structures. Traditional methods of assembling 400,000 + element models can take weeks of effort, severely limiting the range of possible optimization variables. This paper will introduce model generation software developed under NASA sponsorship for the design of both terrestrial and space based mirrors. The software deals with any current mirror manufacturing technique, single substrates, multiple arrays of substrates, as well as the ability to merge submodels into a single large model. The modeler generates both mirror and suspension system elements, suspensions can be created either for each individual petal or the whole mirror. A typical model generation of 250,000 nodes and 450,000 elements only takes 5-10 minutes, much of that time being variable input time. The program can create input decks for ANSYS, ABAQUS and NASTRAN. An archive/retrieval system permits creation of complete trade studies, varying cell size, depth, and petal size, suspension geometry with the ability to recall a particular set of parameters and make small or large changes with ease. The input decks created by the modeler are text files which can be modified by any editor, all the key shell thickness parameters are accessible and comments in deck identify which groups of elements are associated with these parameters. This again makes optimization easier. With ANSYS decks, the nodes representing support attachments are grouped into components; in ABAQUS these are SETS and in NASTRAN as GRIDPOINT SETS, this make integration of these models into large telescope or satellite models possible

  5. Compact fiber optic accelerometer

    Institute of Scientific and Technical Information of China (English)

    Feng Peng; Jun Yang; Bing Wu; Yonggui Yuan; Xingliang Li; Ai Zhou; Libo Yuan


    A compact fiber optic accelerometer based on a Michelson interferometer is proposed and demonstrated.In the proposed system,the sensing element consists of two single-mode fibers glued together by epoxy,which then act as a simple supported beam.By demodulating the optical phase shift,the acceleration is determined as proportional to the force applied on the central position of the two single-mode fibers.This simple model is able to calculate the sensitivity and the resonant frequency of the compact accelerometer.The experimental results show that the sensitivity and the resonant frequency of the accelerometer are 0.42 rad/g and 600 Hz,respectively.

  6. Compact fusion reactors

    CERN Document Server

    CERN. Geneva


    Fusion research is currently to a large extent focused on tokamak (ITER) and inertial confinement (NIF) research. In addition to these large international or national efforts there are private companies performing fusion research using much smaller devices than ITER or NIF. The attempt to achieve fusion energy production through relatively small and compact devices compared to tokamaks decreases the costs and building time of the reactors and this has allowed some private companies to enter the field, like EMC2, General Fusion, Helion Energy, Lawrenceville Plasma Physics and Lockheed Martin. Some of these companies are trying to demonstrate net energy production within the next few years. If they are successful their next step is to attempt to commercialize their technology. In this presentation an overview of compact fusion reactor concepts is given.

  7. Compact Spreader Schemes

    Energy Technology Data Exchange (ETDEWEB)

    Placidi, M.; Jung, J. -Y.; Ratti, A.; Sun, C.


    This paper describes beam distribution schemes adopting a novel implementation based on low amplitude vertical deflections combined with horizontal ones generated by Lambertson-type septum magnets. This scheme offers substantial compactness in the longitudinal layouts of the beam lines and increased flexibility for beam delivery of multiple beam lines on a shot-to-shot basis. Fast kickers (FK) or transverse electric field RF Deflectors (RFD) provide the low amplitude deflections. Initially proposed at the Stanford Linear Accelerator Center (SLAC) as tools for beam diagnostics and more recently adopted for multiline beam pattern schemes, RFDs offer repetition capabilities and a likely better amplitude reproducibility when compared to FKs, which, in turn, offer more modest financial involvements both in construction and operation. Both solutions represent an ideal approach for the design of compact beam distribution systems resulting in space and cost savings while preserving flexibility and beam quality.

  8. Lightweight design of the rectangular mirror using topology optimization (United States)

    Xiang, Meng; Li, Fu


    That minimizing the mass of space optical remote sensor at the same time guaranteeing of structural rigidity and surface shape accuracy, became a new critical research topic. This paper achieves detailed design of meniscus rectangular lens body structure by taking the choice of materials, design of supporting structure and lightweight form of mirror into account. And we established lightweight concrete of the mirror under self-weight by the method of topological optimization design. For the optimization, we used a 3-D model of the rectangular mirror and calculated based on that making minimum weight of the mirror as an objective function constrained by the displacement of the mirror surface. Finally finite element analysis method was adopted to get the optimization results analyzed and compared with the traditional triangular lightweight model. Analysis results prove that: the new mirror is superior to the traditional model in surface accuracy and structural rigidity, PV value, RMS value and the lightweight rate. With enough high dynamic-static stiffness and thermal stability, this kind of mirror can meet the demand under the self-weight and the random vibration environment respectively. So this article puts forward a new idea in the lightweight design of rectangular mirror.

  9. Hydraulic conductivity of compacted zeolites. (United States)

    Oren, A Hakan; Ozdamar, Tuğçe


    Hydraulic conductivities of compacted zeolites were investigated as a function of compaction water content and zeolite particle size. Initially, the compaction characteristics of zeolites were determined. The compaction test results showed that maximum dry unit weight (γ(dmax)) of fine zeolite was greater than that of granular zeolites. The γ(dmax) of compacted zeolites was between 1.01 and 1.17 Mg m(-3) and optimum water content (w(opt)) was between 38% and 53%. Regardless of zeolite particle size, compacted zeolites had low γ(dmax) and high w(opt) when compared with compacted natural soils. Then, hydraulic conductivity tests were run on compacted zeolites. The hydraulic conductivity values were within the range of 2.0 × 10(-3) cm s(-1) to 1.1 × 10(-7) cm s(-1). Hydraulic conductivity of all compacted zeolites decreased almost 50 times as the water content increased. It is noteworthy that hydraulic conductivity of compacted zeolite was strongly dependent on the zeolite particle size. The hydraulic conductivity decreased almost three orders of magnitude up to 39% fine content; then, it remained almost unchanged beyond 39%. Only one report was found in the literature on the hydraulic conductivity of compacted zeolite, which is in agreement with the findings of this study.

  10. Bond Strength Degradation of Corrosive Reinforced Lightweight Concrete

    Institute of Scientific and Technical Information of China (English)

    CHEN Yueshun; LU Yiyan; LI Houxiang; ZENG Sanhai


    The influence of reinforced bar corrosion on the bond degradation in lightweight concrete was studied. Accelerated constant current corrosion tests were performed on lightweight reinforced concrete samples, and the influential factors, such as protective layer thickness, reinforced bar diameter and corrosive level were investigated. The constant current step method was used to measure the electric resistance of the concrete protective cover, which was used to characterize the corrosion level of the rebar. Experimental results indicated that the corrosive resistance increased with increasing the cover dimension and decreasing the reinforced bar diameter, and the rate of decrease in the specimen impedance after cracking depended on the cover dimension. A new medium was offered for the further research on the performance degradation of corrosion lightweight concrete.

  11. Optimum Design of Lightweight Silicon Carbide Mirror Assembly

    Institute of Scientific and Technical Information of China (English)

    HAN Yuanyuan; ZHANG Yumin; HAN Jiecai; ZHANG Jianhan; YAO Wang; ZHOU Yufeng


    According to the design requirement and on the basis of the principle that the thermal expansion coefficient of the support structure should match with that of the mirror, a lightweight silicon carbide primary mirror assembly was designed. Finite element analysis combined with the parameter-optimized method was used during the design. Lightweight cell and rigid rib structure were used for the mirror assembly. The static, dynamic and thermal properties of the primary mirror assembly were analyzed. It is shown that after optimization, the lightweight ratio of the silicon carbide mirror is 52.5%, and the rigidity of the silicon carbide structure is high enough to support the required mirror. When temperature changes, the deformation of the mirror surface is in proportion to the temperature difference.

  12. Physique characteristics of Pan American Games lightweight rowers. (United States)

    DeRose, E H; Crawford, S M; Kerr, D A; Ward, R; Ross, W D


    The emergence of lightweight rowing as an international sport has made the optimization of physique within the weight restrictions a matter of primary importance in selection and training of the participants. The occasion of the Xth Pan American Games provided opportunity to obtain comprehensive anthropometric data on 20 male and 13 female lightweight rower finalists including most of the medal winners. Anthropometric characteristics, somatotype, and proportionality profiles showed the male rowers to be similar in most aspects to a student control sample, with the exception of short sitting height and large transverse chest breadth. The females, on the other hand, appeared to be very different from the control sample, having a number of characteristics similar to those of Olympic rowers. The female lightweight rowers also uniquely demonstrated two distinct physique prototypes.

  13. Autogenous Shrinkage of High Strength Lightweight Aggregate Concrete

    Institute of Scientific and Technical Information of China (English)

    DING Qingjun; TIAN Yaogang; WANG Fazhou; ZHANG Feng; HU Shuguang


    The characteristic of autogenous shrinkage ( AS ) and its effect on high strength lightweight aggregate concrete (HSLAC) were studied. The experimental results show that the main shrinkage of high strength concrete is AS and the amount of cement can affect the AS of HSLAC remarkably. At the early stage the AS of HSLAC is lower than that of high strength normal concrete, but it has a large growth at the later stage. The AS of high strength normal concrete becomes stable at 90d age, but HSLAC still has a high AS growth. It is found that adjusting the volume rate of lightweight aggregate, mixing with a proper dosage of fly ash and raising the water saturation degree of lightweight aggregate can markedly reduce the AS rate of HSLAC.

  14. Compact Q-balls

    CERN Document Server

    Bazeia, D; Marques, M A; Menezes, R; da Rocha, R


    In this work we deal with non-topological solutions of the Q-ball type in two space-time dimensions, in models described by a single complex scalar field that engenders global symmetry. The main novelty is the presence of stable Q-balls solutions that live in a compact interval of the real line and appear from a family of models controlled by two distinct parameters. We find analytical solutions and study their charge and energy, and show how to control the parameters to make the Q-balls classically and quantum mechanically stable.

  15. Compact synchrotron light sources

    CERN Document Server

    Weihreter, Ernst


    This book covers a new niche in circular accelerator design, motivated by the promising industrial prospects of recent micromanufacturing methods - X-ray lithography, synchrotron radiation-based micromachining and microanalysis techniques. It describes the basic concepts and the essential challenges for the development of compact synchrotron radiation sources from an accelerator designer's point of view and gives an outline of the actual state of the art. The volume is intended as an introduction and as a reference for physicists, engineers and managers involved in this rapidly developing fiel

  16. Compact LINAC for deuterons

    Energy Technology Data Exchange (ETDEWEB)

    Kurennoy, S S [Los Alamos National Laboratory; O' Hara, J F [Los Alamos National Laboratory; Rybarcyk, L J [Los Alamos National Laboratory


    We are developing a compact deuteron-beam accelerator up to the deuteron energy of a few MeV based on room-temperature inter-digital H-mode (IH) accelerating structures with the transverse beam focusing using permanent-magnet quadrupoles (PMQ). Combining electromagnetic 3-D modeling with beam dynamics simulations and thermal-stress analysis, we show that IHPMQ structures provide very efficient and practical accelerators for light-ion beams of considerable currents at the beam velocities around a few percent of the speed of light. IH-structures with PMQ focusing following a short RFQ can also be beneficial in the front end of ion linacs.

  17. Design of a simple, lightweight, passive-elastic ankle exoskeleton supporting ankle joint stiffness (United States)

    Kim, Seyoung; Son, Youngsu; Choi, Sangkyu; Ham, Sangyong; Park, Cheolhoon


    In this study, a passive-elastic ankle exoskeleton (PEAX) with a one-way clutch mechanism was developed and then pilot-tested with vertical jumping to determine whether the PEAX is sufficiently lightweight and comfortable to be used in further biomechanical studies. The PEAX was designed to supplement the function of the Achilles tendon and ligaments as they passively support the ankle torque with their inherent stiffness. The main frame of the PEAX consists of upper and lower parts connected to each other by tension springs (N = 3) and lubricated hinge joints. The upper part has an offset angle of 5° with respect to the vertical line when the springs are in their resting state. Each spring has a slack length of 8 cm and connects the upper part to the tailrod of the lower part in the neutral position. The tailrod freely rotates with low friction but has a limited range of motion due to the stop pin working as a one-way clutch. Because of the one-way clutch system, the tension springs store the elastic energy only due to an ankle dorsiflexion when triggered by the stop pin. This clutch mechanism also has the advantage of preventing any inconvenience during ankle plantarflexion because it does not limit the ankle joint motion during the plantarflexion phase. In pilot jumping tests, all of the subjects reported that the PEAX was comfortable for jumping due to its lightweight (approximately 1 kg) and compact (firmly integrated with shoes) design, and subjects were able to nearly reach their maximum vertical jump heights while wearing the PEAX. During the countermovement jump, elastic energy was stored during dorsiflexion by spring extension and released during plantarflexion by spring restoration, indicating that the passive spring torque (i.e., supportive torque) generated by the ankle exoskeleton partially supported the ankle joint torque throughout the process.

  18. Evaluation and comparison of a lightweight bamboo composite (United States)

    Loth, Andreas; Berwing, Michael; Förster, Ralf


    The demand for fast changing production lines and other facilities needs new lightweight and stable systems for partitioning walls. There is also a need for ecological products for this application. The wood like grass bamboo provides a wide potential to substitute conventional wood. A composite lightweight honeycomb like bamboo board was developed and compared with reinforced and unreinforced plywood specimen. The acquired mechanical properties gave a promising result for the usability of bamboo as basis material for wide span boards. It can be manufactured with minimal technical investments, that suits also well for regions with little industry. The ecological assessment of the structure is very positive.

  19. Development of light-weight spherical mirrors for RICH detectors

    CERN Document Server

    Metlica, Fabio


    Glass-coated beryllium and carbon-fiber light-weight spherical mirrors, with radii of curvature of $\\sim$ 2700mm, have been successfully developed and tested as part of the LHCb RICH experimental programme. The low mass mirror is necessary to minimize the amount of material within the LHCb spectrometer acceptance, with a requirement of less than 2% of a radiation length. Both technologies are suitable for light-weight mirror applications. The R&D and characterization of the mirrors are reported.

  20. Ground Fluidization Promotes Rapid Running of a Lightweight Robot (United States)


    Ground fluidization promotes rapid running of a lightweight robot The International Journal of Robotics Research 32(7) 859–869 © The Author(s) 2013...continuously fluidized , and the robot “swam” forward slowly (∼ 0.01 body length/s) using drag on the legs to overcome belly drag. In contrast, a variety of...COVERED 00-00-2013 to 00-00-2013 4. TITLE AND SUBTITLE Ground fluidization promotes rapid running of a lightweight robot 5a. CONTRACT NUMBER 5b

  1. The lightweight structure design of a CFRP mirror (United States)

    Ding, Jiaoteng; Xu, Liang; Ma, Zhen; Xie, Yongjie; Luo, Yao; Wang, Yongjie; Pang, Zhihai


    The advantage of Carbon Fiber Reinforced Polymer (CFRP) is obvious as a common space material for low density, low thermal expansion coefficient and high specific stiffness characteristics, it is the ideal material choice for space optical reflector. Mirror structure with honeycomb can achieve high rates of lightweight, as well as high specific stiffness. For Φ300mm CFRP mirror, accounting of the actual process properties of CFRP, mirror panels laminated based on thermal stability design, honeycomb fabricated using one innovative inlaying-grafting design method. Finally, lightweight structure design of the CFRP primary mirror completed, the thermal stability result of the Φ300mm CFRP mirror achieved is 10nm°C.

  2. Overview of Lightweight Structures for Rotorcraft Engines and Drivetrains (United States)

    Roberts, Gary D.


    This is an overview presentation of research being performed in the Advanced Materials Task within the NASA Subsonic Rotary Wing Project. This research is focused on technology areas that address both national goals and project goals for advanced rotorcraft. Specific technology areas discussed are: (1) high temperature materials for advanced turbines in turboshaft engines; (2) polymer matrix composites for lightweight drive system components; (3) lightweight structure approaches for noise and vibration control; and (4) an advanced metal alloy for lighter weight bearings and more reliable mechanical components. An overview of the technology in each area is discussed, and recent accomplishments are presented.

  3. Reflective Coating for Lightweight X-Ray Optics (United States)

    Chan, Kai-Wing; Zhang, William W.; Windt, David; Hong, Mao-Ling; Saha, Timo; McClelland, Ryan; Sharpe, Marton; Dwivedi, Vivek H.


    X-ray reflective coating for next generation's lightweight, high resolution, optics for astronomy requires thin-film deposition that is precisely fine-tuned so that it will not distort the thin sub-mm substrates. Film of very low stress is required. Alternatively, mirror distortion can be cancelled by precisely balancing the deformation from multiple films. We will present results on metallic film deposition for the lightweight optics under development. These efforts include: low-stress deposition by magnetron sputtering and atomic layer deposition of the metals, balancing of gross deformation with two-layer depositions of opposite stresses and with depositions on both sides of the thin mirrors.

  4. Compact Micromachined Infrared Bandpass Filters for Planetary Spectroscopy (United States)

    Merrell, Willie C., II; Aslam, Shahid; Brown, Ari D.; Chervenak, James A.; Huang, Wei-Chung; Quijada, Manuel; Wollack, Edward


    The future needs of space based observational planetary and astronomy missions include low mass and small volume radiometric instruments that can operate in high radiation and low temperature environments. Here we focus on a central spectroscopic component, the bandpass filter. We model the bandpass response of the filters to target the wavelength of the resonance peaks at 20, 40, and 60 micrometers and report good agreement between the modeled and measured response. We present a technique of using common micromachining processes for semiconductor fabrication to make compact, free standing resonant metal mesh filter arrays with silicon support frames. The process can accommodate multiple detector array architectures and the silicon frame provides lightweight mechanical support with low form factor. We also present a conceptual hybridization of the filters with a detector array.

  5. Lightweight High Temperature Non-Eroding Throat Materials for Propulsion Systems Project (United States)

    National Aeronautics and Space Administration — The innovation in this proposed effort is the development of lightweight, non-eroding nozzle materials for use in propulsion systems. Lightweight structures are...

  6. A compact SADM family (United States)

    Barbet, Vincent; Le Quintrec, Cyrille; Jeandot, Xavier; Chaix, Alain; Grain, Eric; Roux, Jerome


    Alcatel Space has developed a new SADM family driven by cost, modularity, mass and performances. The modularity concept is based on separating the rotation drive function from the electrical transfer function. The drive actuator has been designed for various applications where pointing and reliability is needed. It can be associated with high dissipative rotary devices (SA collectors, RF joints..). The design goal was to minimize the number of parts in order to reach the most simple and compact mechanism. Mass reduction was achieved by reducing as much as possible the load path between the Solar Array interface and the spacecraft interface. Following these guidelines, the drive actuator was developed and qualified on ATV SADM (part od Alcatel Space Solar Array Drive Sub System for ATV). Further more a high power integrated collector was qualified inside the SADM for Geo-stationary telecom satellite (SPACEBUS platforms). Fine thermal and mechanical modeling was necessary to predict SADM behaviors for the numerous thermal environments over the missions (steady and transient cases). These modeling were well correlated through mechanical and thermal balances qualification tests. The challenging approach of thermal dissipation in a compact design leads to a family of 3 SADM capabilities form 2kW up to 15kW per SADM weighing less than 4.5 kg each.

  7. Compaction of Titanium Powders

    Energy Technology Data Exchange (ETDEWEB)

    Gerdemann, Stephen,J; Jablonski, Paul, J


    Accurate modeling of powder densification has been an area of active research for more than 60 years. The earliest efforts were focused on linearization of the data because computers were not readily available to assist with curve-fitting methods. In this work, eight different titanium powders (three different sizes of sponge fines<150 {micro}m,<75 {micro}m, and<45 {micro}m; two different sizes of a hydride-dehydride [HDH]<75 {micro}m and<45 {micro}m; an atomized powder; a commercially pure [CP] Ti powder from International Titanium Powder [ITP]; and a Ti 6 4 alloy powder) were cold pressed in a single-acting die instrumented to collect stress and deformation data during compaction. From these data, the density of each compact was calculated and then plotted as a function of pressure. The results show that densification of all the powders, regardless of particle size, shape, or chemistry, can be modeled accurately as the sum of an initial density plus the sum of a rearrangement term and a work-hardening term. These last two terms are found to be a function of applied pressure and take the form of an exponential rise.

  8. On stable compact minimal submanifolds

    CERN Document Server

    Torralbo, Francisco


    Stable compact minimal submanifolds of the product of a sphere and any Riemannian manifold are classified whenever the dimension of the sphere is at least three. The complete classification of the stable compact minimal submanifolds of the product of two spheres is obtained. Also, it is proved that the only stable compact minimal surfaces of the product of a 2-sphere and any Riemann surface are the complex ones.

  9. Effect of Commercial Synthappret BAP Treatment on the Tailorabilitv of Light-Weight Worsted Wool Fabrics

    Institute of Scientific and Technical Information of China (English)

    Wang Gehui(王革辉); Zhang Weiyuan(张渭源); Postle, R.; Phillips, D.


    By means of measurement with the FAST instruments,the effect of commercial Synthappret BAP treatment on the tailorability of light-weight wool worsted fabrics has been investigated. It was found that the commercial Synthappret BAP treatment improved the tailorability of the light-weight wool fabrics mainly by increasing the bending stiffness of the light-weight wool fabrics.

  10. 76 FR 76360 - Lightweight Thermal Paper From Germany: Notice of Preliminary Results of Antidumping Duty... (United States)


    ... adjustment. See LWTP Decision Memo, at Comment 3. \\7\\ See Lightweight Thermal Paper From Germany: Notice of... International Trade Administration Lightweight Thermal Paper From Germany: Notice of Preliminary Results of... review of the antidumping duty order on lightweight thermal paper from Germany. For the period November...

  11. Density Optimization of Lithium Lanthanum Titanate Ceramics for Lightweight Lithium-Air Batteries (United States)


    Density Optimization of Lithium Lanthanum Titanate Ceramics for Lightweight Lithium -Air Batteries by Claire Weiss Brennan, Victoria Blair...Ground, MD 21005-5069 ARL-TR-7145 November 2014 Density Optimization of Lithium Lanthanum Titanate Ceramics for Lightweight Lithium -Air...COVERED (From - To) 1 June–31 August 2014 4. TITLE AND SUBTITLE Density Optimization of Lithium Lanthanum Titanate Ceramics for Lightweight Lithium

  12. Annotating Evidence Based Clinical Guidelines: A Lightweight Ontology

    NARCIS (Netherlands)

    R. Hoekstra; A. de Waard; R. Vdovjak


    This paper describes a lightweight ontology for representing annotations of declarative evidence based clinical guidelines. We present the motivation and requirements for this representation, based on an analysis of several guidelines. The ontology provides the means to connect clinical questions an

  13. SPONGENT: The Design Space of Lightweight Cryptographic Hashing

    DEFF Research Database (Denmark)

    Bogdanov, Andrey; Knezevic, Miroslav; Leander, Gregor


    The design of secure yet efficiently implementable cryptographic algorithms is a fundamental problem of cryptography. Lately, lightweight cryptography--optimizing the algorithms to fit the most constrained environments--has received a great deal of attention, the recent research being mainly...

  14. FY2010 Annual Progress Report for Lightweighting Materials

    Energy Technology Data Exchange (ETDEWEB)



    The Lightweight Materials activity (LM) within the Vehicle Technologies Program focuses on the development and validation of advanced materials and manufacturing technologies to significantly reduce light and heavy duty vehicle weight without compromising other attributes such as safety, performance, recyclability, and cost.

  15. Making mundane pleasures visible: mediating daily likings with lightweight technology

    NARCIS (Netherlands)

    Kanis, M.; Brinkman, W.-P.


    This article discusses the sharing of daily pleasures with lightweight technology. Two mobile applications called PosiPost Me (Mobile internet edition) and PosiPost Be (Bluetooth edition) were developed to understand the potential of remote and proximity-based sharing of positive messages. These imp

  16. Lightweighting Impacts on Fuel Economy, Cost, and Component Losses

    Energy Technology Data Exchange (ETDEWEB)

    Brooker, A. D.; Ward, J.; Wang, L.


    The Future Automotive Systems Technology Simulator (FASTSim) is the U.S. Department of Energy's high-level vehicle powertrain model developed at the National Renewable Energy Laboratory. It uses a time versus speed drive cycle to estimate the powertrain forces required to meet the cycle. It simulates the major vehicle powertrain components and their losses. It includes a cost model based on component sizing and fuel prices. FASTSim simulated different levels of lightweighting for four different powertrains: a conventional gasoline engine vehicle, a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and a battery electric vehicle (EV). Weight reductions impacted the conventional vehicle's efficiency more than the HEV, PHEV and EV. Although lightweighting impacted the advanced vehicles' efficiency less, it reduced component cost and overall costs more. The PHEV and EV are less cost effective than the conventional vehicle and HEV using current battery costs. Assuming the DOE's battery cost target of $100/kWh, however, the PHEV attained similar cost and lightweighting benefits. Generally, lightweighting was cost effective when it costs less than $6/kg of mass eliminated.

  17. Design of Light-Weight High-Entropy Alloys

    Directory of Open Access Journals (Sweden)

    Rui Feng


    Full Text Available High-entropy alloys (HEAs are a new class of solid-solution alloys that have attracted worldwide attention for their outstanding properties. Owing to the demand from transportation and defense industries, light-weight HEAs have also garnered widespread interest from scientists for use as potential structural materials. Great efforts have been made to study the phase-formation rules of HEAs to accelerate and refine the discovery process. In this paper, many proposed solid-solution phase-formation rules are assessed, based on a series of known and newly-designed light-weight HEAs. The results indicate that these empirical rules work for most compositions but also fail for several alloys. Light-weight HEAs often involve the additions of Al and/or Ti in great amounts, resulting in large negative enthalpies for forming solid-solution phases and/or intermetallic compounds. Accordingly, these empirical rules need to be modified with the new experimental data. In contrast, CALPHAD (acronym of the calculation of phase diagrams method is demonstrated to be an effective approach to predict the phase formation in HEAs as a function of composition and temperature. Future perspectives on the design of light-weight HEAs are discussed in light of CALPHAD modeling and physical metallurgy principles.

  18. Application of CAE technology for Geely car lightweight

    Institute of Scientific and Technical Information of China (English)

    Men Yongxin; Ma Fangwu; Peng Hong; Li Yongsheng


    In order to reduce energy consumption and protect the human survival environment, the lightweight has became the development trend of the world automobile industry. On the premise of ensuring the strength, safety and driving performance of the car, the major car enterprises try to reduce the curb weight of the ear, fuel consumption and emissions. Not only a lot of new technologies and new products have been generated, but also joint vehicle development process and computer aided engineering (CAE) analysis technology have been developed. Since the entry into the "Au- tomobile Lightweight Technology Innovation Strategic Alliance" in Dec. 2007, Geely Group has been focusing on light- weight construction of vehicle and key assemblies in every stage of the vehicle product development. Among vehicles ap- peared on the market and in research, it has presented continuously better performance. The paper describes application examples and successful experience of CAE simulation analysis and performance optimization during the lightweight de- sign and development of a self-developed model of Geely, and looks forward to the prospects for the development of lightweight of Geely vehicle.

  19. FY2013 Lightweight Materials R&D Annual Progress Report

    Energy Technology Data Exchange (ETDEWEB)



    As part of the U.S. Department of Energy’s (DOE’s) Vehicle Technologies Program (VTO), the Lightweight Materials (LM) activity focuses on the development and validation of advanced materials and manufacturing technologies to significantly reduce light and heavy duty vehicle weight without compromising other attributes such as safety, performance, recyclability, and cost.

  20. Solar cell submodule design facilitates assembly of lightweight arrays (United States)

    Yasui, R. K.


    Solar cell submodules with bus bars that leave tabs along one end of the submodule and wires with raised portions along the other end are assembled by interlocking the tabs and wires of adjacent submodules. This structural design is lightweight and reliable and requires no metallic substructure.

  1. A Lightweight Intelligent Virtual Cinematography System for Machinima Production (United States)


    A Lightweight Intelligent Virtual Cinematography System for Machinima Production David K. Elson1, Mark O. Riedl2 1Columbia University, Computer...However, creating quality cinematic visualizations with existing machinima techniques still requires a high degree of talent and effort. We...produces a cinematic visualization. Unlike other virtual cinematography systems, Cambot favors an offline algorithm coupled with an extensible

  2. Lightweight Inexpensive Ozone Lidar Telescope Using a Plastic Fresnel Lens (United States)

    DeYoung, Russell J.; Notari, Anthony; Carrion, William; Pliutau, Denis


    An inexpensive lightweight ozone lidar telescope was designed, constructed and operated during an ozone lidar field campaign. This report summarizes the design parameters and performance of the plastic Fresnel lens telescope and shows the ozone lidar performance compared to Zemax calculations.

  3. A purely flexible lightweight membrane-type acoustic metamaterial (United States)

    Ma, Fuyin; Wu, Jiu Hui; Huang, Meng; Zhang, Weiquan; Zhang, Siwen


    This paper proposes a purely flexible lightweight membrane-type acoustic structure, wherein one kind of flexible lightweight rubber material takes the roles of mass and stiffness and another type of lightweight flexible EVA (ethylene-vinyl acetate copolymer) or plastic material functions as the localized stiffness for each unit. Because both the scatterers and base are constituted by the same material, this type of structure breaks the limitation that the metamaterials and phononic crystals need different materials with relatively large density and elasticity modulus ratios to play the roles of the scatterers and base respectively. Based on the band structures with different units, mass block shapes and size parameters, it is suggested that the shapes of the mass block can significantly affect the band structure. In addition, this type of structure could not only open a full band gap in the low-frequency range below 500 Hz, but also obtain an ultra-low-frequency bending wave band gap in the range below 100 Hz. Finally, we take into account the semi-infinite medium as a component, and calculate the sound transmission loss (STL) to evaluate the interaction between the structure and air. An experimental validation employing the cylindrical mass structure was developed to directly support the simulation results. Since the structures proposed in this study have achieved a purely flexible lightweight design, there exists an important promotion effect to realize the engineering applications of the acoustic metamaterials in practice.


    Directory of Open Access Journals (Sweden)

    NOZEMTСEV Alexandr Sergeevich


    Full Text Available The paper presents the results of research aimed at development of nanomodified high-strength lightweight concrete for construction. The developed concretes are of low average density and high ultimate compressive strength. It is shown that to produce this type of concrete one need to use hollow glass and aluminosilicate microspheres. To increase the durability of adhesion between cement stone and fine filler the authors offer to use complex nanodimensinal modifier based on iron hydroxide sol and silica sol as a surface nanomodifier for hollow microspheres. It is hypothesized that the proposed modifier has complex effect on the activity of the cement hydration and, at the same time increases bond strength between filler and cement-mineral matrix. The compositions for energy-efficient nanomodified high-strength lightweight concrete which density is 1300…1500 kg/m³ and compressive strength is 40…65 MPa have been developed. The approaches to the design of high-strength lightweight concrete with density of less than 2000 kg/m³ are formulated. It is noted that the proposed concretes possess dense homogeneous structure and moderate mobility. Thus, they allow processing by vibration during production. The economic and practical implications for realization of high-strength lightweight concrete in industrial production have been justified.

  5. Atacama Compact Array Antennas

    CERN Document Server

    Saito, Masao; Nakanishi, Kouichiro; Naoi, Takahiro; Yamada, Masumi; Saito, Hiro; Ikenoue, Bungo; Kato, Yoshihiro; Morita, Kou-ichiro; Mizuno, Norikazu; Iguchi, Satoru


    We report major performance test results of the Atacama Compact Array (ACA) 7-m and 12-m antennas of ALMA (Atacama Large Millimeter/submillimeter Array). The four major performances of the ACA antennas are all-sky pointing (to be not more than 2.0 arcsec), offset pointing (to be < 0.6 arcsec) surface accuracy (< 25(20) micrometer for 12(7)m-antenna), stability of path-length (15 micrometer over 3 min), and high servo capability (6 degrees/s for Azimuth and 3 degrees/s for Elevation). The high performance of the ACA antenna has been extensively evaluated at the Site Erection Facility area at an altitude of about 2900 meters. Test results of pointing performance, surface performance, and fast motion capability are demonstrated.

  6. The Finslerian compact star model

    Energy Technology Data Exchange (ETDEWEB)

    Rahaman, Farook; Paul, Nupur [Jadavpur University, Department of Mathematics, Kolkata, West Bengal (India); De, S.S. [University of Calcutta, Department of Applied Mathematics, Kolkata (India); Ray, Saibal [Government College of Engineering and Ceramic Technology, Department of Physics, Kolkata, West Bengal (India); Jafry, M.A.K. [Shibpur Dinobundhoo Institution, Department of Physics, Howrah, West Bengal (India)


    We construct a toy model for compact stars based on the Finslerian structure of spacetime. By assuming a particular mass function, we find an exact solution of the Finsler-Einstein field equations with an anisotropic matter distribution. The solutions are revealed to be physically interesting and pertinent for the explanation of compact stars. (orig.)

  7. Warm compacting behavior of stainless steel powders

    Institute of Scientific and Technical Information of China (English)

    肖志瑜; 柯美元; 陈维平; 召明; 李元元


    The warm compacting behaviors of four different kinds of stainless steel powders, 304L, 316L, 410L and 430L, were studied. The results show that warm compaction can be applied to stainless steel powders. The green densities and strengths of compacts obtained through warm compaction are generally higher than those obtained through cold compaction. The compacting behaviors in warm compaction and cold compaction are similar.Under the compacting pressure of 700 MPa, the warm compacted densities are 0. 10 - 0.22 g/cm3 higher than the cold compacted ones, and the green strengths are 11.5 %-50 % higher. The optimal warm compacting temperature is 100 - 110 ℃. In the die wall lubricated warm compaction, the optimum internal lubricant content is 0.2%.

  8. Compact Dexterous Robotic Hand (United States)

    Lovchik, Christopher Scott (Inventor); Diftler, Myron A. (Inventor)


    A compact robotic hand includes a palm housing, a wrist section, and a forearm section. The palm housing supports a plurality of fingers and one or more movable palm members that cooperate with the fingers to grasp and/or release an object. Each flexible finger comprises a plurality of hingedly connected segments, including a proximal segment pivotally connected to the palm housing. The proximal finger segment includes at least one groove defining first and second cam surfaces for engagement with a cable. A plurality of lead screw assemblies each carried by the palm housing are supplied with power from a flexible shaft rotated by an actuator and output linear motion to a cable move a finger. The cable is secured within a respective groove and enables each finger to move between an opened and closed position. A decoupling assembly pivotally connected to a proximal finger segment enables a cable connected thereto to control movement of an intermediate and distal finger segment independent of movement of the proximal finger segment. The dexterous robotic hand closely resembles the function of a human hand yet is light weight and capable of grasping both heavy and light objects with a high degree of precision.

  9. A Mass Computation Model for Lightweight Brayton Cycle Regenerator Heat Exchangers (United States)

    Juhasz, Albert J.


    Based on a theoretical analysis of convective heat transfer across large internal surface areas, this paper discusses the design implications for generating lightweight gas-gas heat exchanger designs by packaging such areas into compact three-dimensional shapes. Allowances are made for hot and cold inlet and outlet headers for assembly of completed regenerator (or recuperator) heat exchanger units into closed cycle gas turbine flow ducting. Surface area and resulting volume and mass requirements are computed for a range of heat exchanger effectiveness values and internal heat transfer coefficients. Benefit cost curves show the effect of increasing heat exchanger effectiveness on Brayton cycle thermodynamic efficiency on the plus side, while also illustrating the cost in heat exchanger required surface area, volume, and mass requirements as effectiveness is increased. The equations derived for counterflow and crossflow configurations show that as effectiveness values approach unity, or 100 percent, the required surface area, and hence heat exchanger volume and mass tend toward infinity, since the implication is that heat is transferred at a zero temperature difference. To verify the dimensional accuracy of the regenerator mass computational procedure, calculation of a regenerator specific mass, that is, heat exchanger weight per unit working fluid mass flow, is performed in both English and SI units. Identical numerical values for the specific mass parameter, whether expressed in lb/(lb/sec) or kg/ (kg/sec), show the dimensional consistency of overall results.

  10. Evidence for (and Against) Progenitor Bias in the Size Growth of Compact Red Galaxies

    CERN Document Server

    Keating, Stephanie K; Schiavon, Ricardo P; Graves, Genevieve; Damjanov, Ivana; Yan, Renbin; Newman, Jeffrey; Simard, Luc


    Most massive passive galaxies are compact at high redshifts, but similarly compact massive galaxies are rare in the local universe. The most common interpretation of this phenomenon is that massive galaxies have grown in size by a factor of about five since redshift z=2. An alternative explanation is that recently quenched massive galaxies are larger (a "progenitor bias"). In this paper we explore the importance of progenitor bias by looking for systematic differences in the stellar populations of compact early-type galaxies in the DEEP2 survey as a function of size. Our analysis is based on applying the statistical technique of bootstrap resampling to constrain differences in the median ages of our samples and to begin to characterize the distribution of stellar populations in our co-added spectra. The light-weighted ages of compact early-type galaxies at redshifts 0.5 < z < 1.4 are compared to those of a control sample of larger galaxies at similar redshifts. We find that massive compact early-type ga...

  11. Hot stamping advanced manufacturing technology of lightweight car body

    CERN Document Server

    Hu, Ping; He, Bin


    This book summarizes the advanced manufacturing technology of original innovations in hot stamping of lightweight car body. A detailed description of the technical system and basic knowledge of sheet metal forming is given, which helps readers quickly understand the relevant knowledge in the field. Emphasis has been placed on the independently developed hot stamping process and equipment, which help describe the theoretical and experimental research on key problems involving stress field, thermal field and phase transformation field in hot stamping process. Also, a description of the formability at elevated temperature and the numerical simulation algorithms for high strength steel hot stamping is given in combination with the experiments. Finally, the book presents some application cases of hot stamping technology such as the lightweight car body design using hot stamping components and gradient hardness components, and the cooling design of the stamping tool. This book is intended for researchers, engineers...


    Directory of Open Access Journals (Sweden)



    Full Text Available This study presents the results of the investigation of the response of lightweight concrete to elevated temperature. Available literature indicates that research works have not been carried out in this area. The variables are: mix proportion, water/cement ratio, curing age and temperature. The parameters that were measured are: compressive strength, density and bond characteristics of the concrete matrix. The results showed that the compressive strength of concrete decreased with increase in water/cement ratio and temperature but increased with increase in curing age and cement content while the density decreased with increase in temperature. The bond between the concrete matrix also decreased as the temperature increased. Lightweight concrete containing periwinkle shells is only suitable for structures that will be subjected to temperature less than 300oC.

  13. Computational imaging using lightweight diffractive-refractive optics. (United States)

    Peng, Yifan; Fu, Qiang; Amata, Hadi; Su, Shuochen; Heide, Felix; Heidrich, Wolfgang


    Diffractive optical elements (DOE) show great promise for imaging optics that are thinner and more lightweight than conventional refractive lenses while preserving their light efficiency. Unfortunately, severe spectral dispersion currently limits the use of DOEs in consumer-level lens design. In this article, we jointly design lightweight diffractive-refractive optics and post-processing algorithms to enable imaging under white light illumination. Using the Fresnel lens as a general platform, we show three phase-plate designs, including a super-thin stacked plate design, a diffractive-refractive-hybrid lens, and a phase coded-aperture lens. Combined with cross-channel deconvolution algorithm, both spherical and chromatic aberrations are corrected. Experimental results indicate that using our computational imaging approach, diffractive-refractive optics is an alternative candidate to build light efficient and thin optics for white light imaging.

  14. Computational imaging using lightweight diffractive-refractive optics

    KAUST Repository

    Peng, Yifan


    Diffractive optical elements (DOE) show great promise for imaging optics that are thinner and more lightweight than conventional refractive lenses while preserving their light efficiency. Unfortunately, severe spectral dispersion currently limits the use of DOEs in consumer-level lens design. In this article, we jointly design lightweight diffractive-refractive optics and post-processing algorithms to enable imaging under white light illumination. Using the Fresnel lens as a general platform, we show three phase-plate designs, including a super-thin stacked plate design, a diffractive-refractive-hybrid lens, and a phase coded-aperture lens. Combined with cross-channel deconvolution algorithm, both spherical and chromatic aberrations are corrected. Experimental results indicate that using our computational imaging approach, diffractive-refractive optics is an alternative candidate to build light efficient and thin optics for white light imaging.

  15. Cost-effective lightweight mirrors for aerospace and defense (United States)

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


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

  16. Tendon-Actuated Lightweight In-Space MANipulator (TALISMAN) (United States)

    Dorsey, John T.; Doggett, William R.; Komendera, Erik E.


    The robotic architecture of State-of-the-Art (SOA) space manipulators, represented by the Shuttle Remote Manipulator System (SRMS), inherently limits their capabilities to extend reach, reduce mass, apply force and package efficiently. TALISMAN uses a new and innovative robotic architecture that incorporates a combination of lightweight truss links, a novel hinge joint, tendon-articulation and passive tension stiffening to achieve revolutionary performance. A TALISMAN with performance similar to the SRMS has 1/10th of its mass and packages in 1/7th of its volume. The TALISMAN architecture allows its reach to be scaled over a large range; from 10 to over 300 meters. In addition, the dexterity (number of degrees-of-freedom) can be easily adjusted without significantly impacting manipulator mass because the joints are very lightweight.

  17. Lightweight autoclavable wide-angle contact lens for vitreous surgery. (United States)

    Chalam, K V; Gupta, Shailesh K; Agarwal, Swati


    The authors describe an autoclavable, self-stabilizing, lightweight wide-angle contact lens for vitrectomy. The lens has two optical pieces with perforated plastic casing to sustain a high temperature (150 degrees C) for autoclaving. The lens has a 106 degrees static and 127 degrees dynamic field of view. The footplates and reduced weight (2.4 grams) due to the plastic casing allow self-stabilization of the lens. The open lens design.with high temperature resistant plastic prevents fogging during autoclaving and surgery. The autoclavable, self-stabilizing, lightweight wide-angle contact lens allows visualization of the peripheral retina during surgery and faster sterilization by autoclaving between surgeries without the disadvantage of lens fogging.

  18. A Light-Weight Statically Scheduled Network-on-Chip

    DEFF Research Database (Denmark)

    Sørensen, Rasmus Bo; Schoeberl, Martin; Sparsø, Jens


    This paper investigates how a light-weight, statically scheduled network-on-chip (NoC) for real-time systems can be designed and implemented. The NoC provides communication channels between all cores with equal bandwidth and latency. The design is FPGA-friendly and consumes a minimum of resources....... We implemented a 64 core 16-bit multiprocessor connected with the proposed NoC in a low-cost FPGA....

  19. Deployment of Lightweight Shock Mitigating Boat Manufacturing Innovation (United States)


    VARTM Hull 1267 760 Deck 702 399 Console 540 350 Total 2509 1509 % Current 100% 60% % Savings - 40% Deployment of Lightweight Shock Mitigating...1430 47 Weight Evaluation- Baseline Boat Weights (lb) Segment Baseline 850 A 850 B 850 B-OM Fabrication Method Open Mold Open Mold VARTM Open...Segment Baseline 850 A 850 B 850 B-OM Fabrication Method Open Mold Open Mold VARTM Open Mold Hull 1115 843 717 789 Deck 665 587 481 529

  20. Polymer Substrates For Lightweight, Thin-Film Solar Cells (United States)

    Lewis, Carol R.


    Substrates survive high deposition temperatures. High-temperature-resistant polymers candidate materials for use as substrates of lightweight, flexible, radiation-resistant solar photovoltaic cells. According to proposal, thin films of copper indium diselenide or cadmium telluride deposited on substrates to serve as active semiconductor layers of cells, parts of photovoltaic power arrays having exceptionally high power-to-weight ratios. Flexibility of cells exploited to make arrays rolled up for storage.

  1. Mechanical, Thermal and Functional Properties of Green Lightweight Foamcrete


    Md Azree Othuman Mydin; Norizal Md Noordin


    In recent times, the construction industry has revealed noteworthy attention in the use of lightweight foamcrete as a building material due to its many favourable characteristics such as lighter weight, easy to fabricate, durable and cost effective. Foamcrete is a material consisting of Portland cement paste or cement filler matrix (mortar) with a homogeneous pore structure created by introducing air in the form of small bubbles. With a proper control in dosage of foam and m...

  2. Magnesium Technology and Manufacturing for Ultra Lightweight Armored Ground Vehicles (United States)


    Bruce Davis and Rick DeLorme Magnesium Elektron North America, Inc. A reprint from the Proceedings of the 2008 Army Science Conference...SUPPLEMENTARY NOTES *Magnesium Elektron North America, Inc., 1001 College St., Madison, IL 62060 A reprint from the Proceedings of the 2008 Army Science...initial emphasis on the Elektron WE43 alloy system for lightweight armored ground vehicle applications. Engineering design factors are reviewed and

  3. Light-weight cyptography for resource constrained environments (United States)

    Baier, Patrick; Szu, Harold


    We give a survey of "light-weight" encryption algorithms designed to maximise security within tight resource constraints (limited memory, power consumption, processor speed, chip area, etc.) The target applications of such algorithms are RFIDs, smart cards, mobile phones, etc., which may store, process and transmit sensitive data, but at the same time do not always support conventional strong algorithms. A survey of existing algorithms is given and new proposal is introduced.

  4. Tailored Buckling Microlattices as Reusable Light-Weight Shock Absorbers. (United States)

    Frenzel, Tobias; Findeisen, Claudio; Kadic, Muamer; Gumbsch, Peter; Wegener, Martin


    Structures and materials absorbing mechanical (shock) energy commonly exploit either viscoelasticity or destructive modifications. Based on a class of uniaxial light-weight geometrically nonlinear mechanical microlattices and using buckling of inner elements, either a sequence of snap-ins followed by irreversible hysteretic - yet repeatable - self-recovery or multistability is achieved, enabling programmable behavior. Proof-of-principle experiments on three-dimensional polymer microstructures are presented.

  5. Lightweight Sandwich Panel in Cold Stores and Refrigerated Warehouses


    Chidom, Charles


    The use of sandwich panels has gained considerable recognition in the construction industry and more use of this composite structure is ever increasing. This study highlights and familiarizes the use of lightweight sandwich panel in refrigerated warehouses and cold storage facility and construction and the challenges such construction faces in warm climates considering the effects of thermal load. The study was commissioned by HAMK Sheet Metal Center, the steel research and development ce...

  6. Ultra-lightweight mirror manufacturing and radiation response study (United States)

    Fitzsimmons, T. C.; Crowe, D. A.


    The requirements for making ultra-lightweight mirrors of Ultra-Low Expansion (ULE) fused silica by frit bonding are investigated. A manufacturing assessment of the facilities needed to scale the mirror technology to 4 meters in diameter is included. A front surface flux loading thermal test of a.5M diameter frit bonded ULE mirror is also included. The test was supported by detailed modeling and analysis.

  7. Lightweight shape memory self-deployable structures for Gossamer applications (United States)

    Sokolowski, Witold


    Currently, existing approaches for producing large, ultra-lightweight, deployable structures in space typically rely upon electro-mechanical mechanisms and mechanically expandable that are heavy, not stowage volume efficient, expensive and complex. Therefore, one of the major efforts at NASA and DoD has been to develop expandable structures characterized by low mass and small launch volume. As a result, space inflatable structures have emerged 9-10 years ago.

  8. Characterization of porous acoustic materials applied to lightweight partition walls


    Fangueiro, Raúl; Velosa, J. C.; Macieira, Mónica; Mendonça, Paulo


    The increased need to save material and energetic resources, allied with a growing concern on the environmental issues and incertitude on the evolution of the economy, has impelled minimalist-approaches to Architecture and Engineering, reducing to the minimum necessary expression the building elements. The development of new lightweight materials, most of them composites with fibrous reinforcement systems, has interest for building materials and textile industries. However, the...

  9. Compact instantaneous water heater

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Jorge G.W.; Machado, Antonio R.; Ferraz, Andre D.; Rocha, Ivan C.C. da; Konishi, Ricardo [Companhia de Gas de Santa Catarina (SCGAS), Florianopolis, SC (Brazil); Lehmkuhl, Willian A.; Francisco Jr, Roberto W.; Hatanaka, Ricardo L.; Pereira, Fernando M.; Oliveira, Amir A.M. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)


    This paper presents an experimental study of combustion in an inert porous medium in a liquid heating device application. This project aims to increase efficiency in the application of natural gas in residential and commercial sectors with the use of advanced combustion and heat transfer. The goal is to facilitate the development of a high performance compact water heater allowing hot water supply for up to two simultaneous showers. The experiment consists in a cylindrical porous burner with an integrated annular water heat exchanger. The reactants were injected radially into the burner and the flame stabilizes within the porous matrix. The water circulates in a coiled pipe positioned at the center of the burner. This configuration allows for heat transfer by conduction and radiation from the solid matrix to the heat exchanger. This article presented preliminary experimental results of a new water heater based on an annular porous burner. The range of equivalence ratios tested varied from 0.65 to 0.8. The power range was varied from 3 to 5 kW. Increasing the equivalence ratio or decreasing the total power input of the burner resulted in increased thermal efficiencies of the water heater. Thermal efficiencies varying from 60 to 92% were obtained. The condition for the goal of a comfortable bath was 20 deg C for 8-12 L/min. This preliminary prototype has achieved water temperature of 11deg C for 5 L/min. Further optimizations will be necessary in order to achieve intense heating with high thermal efficiency. (author)

  10. Compact Grism Spectrometer (United States)

    Teare, S. W.


    Many observatories and instrument builders are retrofitting visible and near-infrared spectrometers into their existing imaging cameras. Camera designs that reimage the focal plane and have the optical filters located in a pseudo collimated beam are ideal candidates for the addition of a spectrometer. One device commonly used as the dispersing element for such spectrometers is a grism. The traditional grism is constructed from a prism that has had a diffraction grating applied on one surface. The objective of such a design is to use the prism wedge angle to select the desired "in-line" or "zero-deviation" wavelength that passes through on axis. The grating on the surface of the prism provides much of the dispersion for the spectrometer. A grism can also be used in a "constant-dispersion" design which provides an almost linear spatial scale across the spectrum. In this paper we provide an overview of the development of a grism spectrometer for use in a near infrared camera and demonstrate that a compact grism spectrometer can be developed on a very modest budget that can be afforded at almost any facility. The grism design was prototyped using visible light and then a final device was constructed which provides partial coverage in the near infrared I, J, H and K astronomical bands using the appropriate band pass filter for order sorting. The near infrared grism presented here provides a spectral resolution of about 650 and velocity resolution of about 450 km/s. The design of this grism relied on a computer code called Xspect, developed by the author, to determine the various critical parameters of the grism. This work was supported by a small equipment grant from NASA and administered by the AAS.

  11. Vehicular hydrogen storage using lightweight tanks (regenerative fuel cell systems)

    Energy Technology Data Exchange (ETDEWEB)

    Mitlitsky, F; Myers, B; Weisberg, A H


    Energy storage systems with extremely high specific energy (>400 Wh/kg) have been designed that use lightweight tankage to contain the gases generated by reversible (unitized) regenerative fuel cells (URFCs). Lawrence Livermore National Laboratory (LLNL) will leverage work for aerospace applications supported by other sponsors (including BMDO, NASA, and USAF) to develop URFC systems for transportation and utility applications. Lightweight tankage is important for primary fuel cell powered vehicles that use on-board storage of hydrogen. Lightweight pressure vessels with state-of-the-art performance factors were designed, and prototypes are being fabricated to meet the DOE 2000 goals (4000 Wh/kg, 12% hydrogen by weight, 700 Wh/liter, and $20/kWh in high volume production). These pressure vessels use technologies that are easily adopted by industrial partners. Advanced liners provide permeation barriers for gas storage and are mandrels for composite overwrap. URFCs are important to the efficient use of hydrogen as a transportation fuel and enabler of renewable energy. H{sub 2}/halogen URFCs may be advantageous for stationary applications whereas H{sub 2}/O{sub 2} or H{sub 2}/air URFCs are advantageous for vehicular applications. URFC research and development is required to improve performance (efficiency), reduce catalyst loading, understand engineering operation, and integrate systems. LLNL has the experimental equipment and advanced URFC membrane electrode assemblies (some with reduced catalyst loading) for evaluating commercial hardware (not funded by DOE in FY1999).

  12. Hummingbird: Ultra-Lightweight Cryptography for Resource-Constrained Devices (United States)

    Engels, Daniel; Fan, Xinxin; Gong, Guang; Hu, Honggang; Smith, Eric M.

    Due to the tight cost and constrained resources of high-volume consumer devices such as RFID tags, smart cards and wireless sensor nodes, it is desirable to employ lightweight and specialized cryptographic primitives for many security applications. Motivated by the design of the well-known Enigma machine, we present a novel ultra-lightweight cryptographic algorithm, referred to as Hummingbird, for resource-constrained devices in this paper. Hummingbird can provide the designed security with small block size and is resistant to the most common attacks such as linear and differential cryptanalysis. Furthermore, we also present efficient software implementation of Hummingbird on the 8-bit microcontroller ATmega128L from Atmel and the 16-bit microcontroller MSP430 from Texas Instruments, respectively. Our experimental results show that after a system initialization phase Hummingbird can achieve up to 147 and 4.7 times faster throughput for a size-optimized and a speed-optimized implementations, respectively, when compared to the state-of-the-art ultra-lightweight block cipher PRESENT[10] on the similar platforms.

  13. Ceramic/polymer functionally graded material (FGM) lightweight armor system

    Energy Technology Data Exchange (ETDEWEB)

    Petrovic, J.J.; McClellan, K.J.


    This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Functionally graded material is an enabling technology for lightweight body armor improvements. The objective was to demonstrate the ability to produce functionally graded ceramic-polymer and ceramic-metal lightweight armor materials. This objective involved two aspects. The first and key aspect was the development of graded-porosity boron-carbide ceramic microstructures. The second aspect was the development of techniques for liquid infiltration of lightweight metals and polymers into the graded-porosity ceramic. The authors were successful in synthesizing boron-carbide ceramic microstructures with graded porosity. These graded-porosity boron-carbide hot-pressed pieces were then successfully liquid-infiltrated in vacuum with molten aluminum at 1,300 C, and with liquid polymers at room temperature. Thus, they were able to demonstrate the feasibility of producing boron carbide-aluminum and boron carbide-polymer functionally graded materials.

  14. Lightweight ZERODUR: Validation of Mirror Performance and Mirror Modeling Predictions (United States)

    Hull, Tony; Stahl, H. Philip; Westerhoff, Thomas; Valente, Martin; Brooks, Thomas; Eng, Ron


    Upcoming spaceborne missions, both moderate and large in scale, require extreme dimensional stability while relying both upon established lightweight mirror materials, and also upon accurate modeling methods to predict performance under varying boundary conditions. We describe tests, recently performed at NASA's XRCF chambers and laboratories in Huntsville Alabama, during which a 1.2 m diameter, f/1.2988% lightweighted SCHOTT lightweighted ZERODUR(TradeMark) mirror was tested for thermal stability under static loads in steps down to 230K. Test results are compared to model predictions, based upon recently published data on ZERODUR(TradeMark). In addition to monitoring the mirror surface for thermal perturbations in XRCF Thermal Vacuum tests, static load gravity deformations have been measured and compared to model predictions. Also the Modal Response(dynamic disturbance) was measured and compared to model. We will discuss the fabrication approach and optomechanical design of the ZERODUR(TradeMark) mirror substrate by SCHOTT, its optical preparation for test by Arizona Optical Systems (AOS). Summarize the outcome of NASA's XRCF tests and model validations

  15. Mechanical analysis of lightweight constructions manufactured with fused deposition modeling (United States)

    Bagsik, A.; Josupeit, S.; Schoeppner, V.; Klemp, E.


    Additive production techniques have the advantage of manufacturing parts without needing a forming tool. One of the most used additive manufacturing processes is "Fused Deposition Modeling" (FDM) which allows the production of prototypes and end-use parts. Due to the manufacture layer by layer, also complex part geometries can be created in one working step. Furthermore, lightweight parts with specific inner core structures can be manufactured in order to achieve good weightrelated strength properties. In this paper the mechanical behavior of lightweight parts manufactured with the 3D production system Fortus 400mc from Stratasys and the material Polyetherimide (PEI) with the trade name Ultem*9085 is analyzed. The test specimens were built up with different inner structures and building directions. Therefore, test specimens with known lightweight core geometries (e.g. corrugated and honeycomb cores) were designed. A four-point bending test was conducted to analyze the strength properties as well as the weight-related strength properties. Additionally the influence of the structure width, the structure wall thickness and the top layer thickness was analyzed using a honeycomb structure.

  16. Compact, Airborne Multispecies Sensor Project (United States)

    National Aeronautics and Space Administration — The Small Business Innovative Research Phase I proposal seeks to develop a compact mid-infrared laser spectrometer to benefit Earth science research activities. To...

  17. Countably determined compact abelian groups

    CERN Document Server

    Dikranjan, Dikran


    For an abelian topological group G let G^* be the dual group of all continuous characters endowed with the compact open topology. A subgroup D of G determines G if the restriction homomorphism G^* --> D^* of the dual groups is a topological isomorphism. Given a scattered compact subset X of an infinite compact abelian group G such that |X|compact abelian group determined by its countable subgroup must be metrizable. This gives a negative answer to questions of Comfort, Hernandez, Macario, Raczkowski and Trigos-Arrieta, as well as provides short proofs of main results established in three manuscripts by these authors.

  18. Compact energy conversion module Project (United States)

    National Aeronautics and Space Administration — This STTR project delivers a compact vibration-based Energy Conversion Module (ECM) that powers sensors for purposes like structural health monitoring (SHM). NASA...

  19. Compact, Ultrasensitive Formaldehyde Monitor Project (United States)

    National Aeronautics and Space Administration — The Small Business Innovative Research Phase II proposal seeks to develop a compact UV laser ?based sensor for Earth science and planetary atmosphere exploration....

  20. What Is Business's Social Compact? (United States)

    Avishai, Bernard


    Under the "new" social compact, businesses must focus on continuous learning and thus have both an obligation to support teaching and an opportunity to profit from it. Learning organizations must also be teaching organizations. (SK)

  1. Compact low resolution spectrograph, an imaging and long slit spectrograph for robotic telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Rabaza, O., E-mail: [Department of Civil Engineering, University of Granada, Severo Ochoa Str. s/n, 18071 Granada (Spain); Institute of Astrophysics of Andalucía (CSIC), Glorieta de la Astronomía s/n, 18008 Granada (Spain); Jelinek, M.; Cunniffe, R.; Ruedas-Sánchez, J. [Institute of Astrophysics of Andalucía (CSIC), Glorieta de la Astronomía s/n, 18008 Granada (Spain); Castro-Tirado, A. J. [Institute of Astrophysics of Andalucía (CSIC), Glorieta de la Astronomía s/n, 18008 Granada (Spain); Department of Systems and Automatic Engineering, University of Málaga, 29071 Málaga (Spain); Zeman, J. [Astronomical Institute of the Academic of Sciences, Fricova 298, 25165 Ondrejov (Czech Republic); Hudec, R. [Astronomical Institute of the Academic of Sciences, Fricova 298, 25165 Ondrejov (Czech Republic); Faculty of Electrical Engineering, Czech Technical University, Technicka 2, Praha 6 (Czech Republic); Sabau-Graziati, L. [National Institute of Aerospace Technology, Carretera de Ajalvir, 28850 Madrid (Spain)


    The COmpact LOw REsolution Spectrograph (COLORES) is a compact and lightweight (13 kg) f/8 imaging spectrograph designed for robotic telescopes, now installed and operating on the TELMA, a rapid-slewing 60 cm telescope of the BOOTES-2 observatory in Málaga (Spain). COLORES is a multi-mode instrument that enables the observer to seamlessly switch between low-dispersion spectroscopy and direct imaging modes during an observation. In this paper, we describe the instrument and its development, from the initial scientific requirements through the optical design process to final configuration with theoretical performance calculations. The mechanical and electronic design is described, methods of calibration are discussed and early laboratory and scientific results are shown.

  2. Brittleness Generation Mechanism and Failure Model of High Strength Lightweight Aggregate Concrete

    Institute of Scientific and Technical Information of China (English)


    The brittleness generation mechanism of high strength lightweight aggregate concrete(HSLWAC) was presented, and it was indicated that lightweight aggregate was the vulnerable spot,initiating brittleness. Based on the analysis of the brittleness failure by the load-deflection curve, the brittleness presented by HSLWAC was more prominent compared with ordinary lightweight aggregate concrete of the same strength grade. The model of brittleness failure was also established.

  3. Compact Intracloud Discharges

    Energy Technology Data Exchange (ETDEWEB)

    Smith, David A. [Univ. of Colorado, Boulder, CO (United States)


    In November of 1993, mysterious signals recorded by a satellite-borne broadband VHF radio science experiment called Blackboard led to a completely unexpected discovery. Prior to launch of the ALEXIS satellite, it was thought that its secondary payload, Blackboard, would most often detect the radio emissions from lightning when its receiver was not overwhelmed by noise from narrowband communication carriers. Instead, the vast majority of events that triggered the instrument were isolated pairs of pulses that were one hundred times more energetic than normal thunderstorm electrical emissions. The events, which came to be known as TIPPs (for transionospheric pulse pairs), presented a true mystery to the geophysics community. At the time, it was not even known whether the events had natural or anthropogenic origins. After two and one half years of research into the unique signals, two ground-based receiver arrays in New Mexico first began to detect and record thunderstorm radio emissions that were consistent with the Blackboard observations. On two occasions, the ground-based systems and Blackboard even recorded emissions that were produced by the same exact events. From the ground based observations, it has been determined that TIPP events areproduced by brief, singular, isolated, intracloud electrical discharges that occur in intense regions of thunderstorms. These discharges have been dubbed CIDS, an acronym for compact intracloud discharges. During the summer of 1996, ground-based receiver arrays were used to record the electric field change signals and broadband HF emissions from hundreds of CIDS. Event timing that was accurate to within a few microseconds made possible the determination of source locations using methods of differential time of arrival. Ionospheric reflections of signals were recorded in addition to groundwave/line-of-sight signals and were used to determine accurate altitudes for the discharges. Twenty-four CIDS were recorded from three

  4. Compactness in intuitionistic fuzzy topological spaces

    Directory of Open Access Journals (Sweden)

    S. E. Abbas


    Full Text Available We introduce fuzzy almost continuous mapping, fuzzy weakly continuous mapping, fuzzy compactness, fuzzy almost compactness, and fuzzy near compactness in intuitionistic fuzzy topological space in view of the definition of Å ostak, and study some of their properties. Also, we investigate the behavior of fuzzy compactness under several types of fuzzy continuous mappings.

  5. The Construction of Finer Compact Topologies



    It is well known that each locally compact strongly sober topology is contained in a compact Hausdorff topology; just take the supremum of its topology with its dual topology. On the other hand, examples of compact topologies are known that do not have a finer compact Hausdorff topology. This led to the question (first explicitly formulated by D.E. Cameron) whether each compact topology is contained in a compact topology with respect to which all compact sets are closed. (For the obvious r...

  6. Compactly convex sets in linear topological spaces

    CERN Document Server

    Banakh, T; Ravsky, O


    A convex subset X of a linear topological space is called compactly convex if there is a continuous compact-valued map $\\Phi:X\\to exp(X)$ such that $[x,y]\\subset\\Phi(x)\\cup \\Phi(y)$ for all $x,y\\in X$. We prove that each convex subset of the plane is compactly convex. On the other hand, the space $R^3$ contains a convex set that is not compactly convex. Each compactly convex subset $X$ of a linear topological space $L$ has locally compact closure $\\bar X$ which is metrizable if and only if each compact subset of $X$ is metrizable.

  7. Cryogenic Piezo Actuators for Lightweight, Large Aperture, Deployable Membrane Mirrors Project (United States)

    National Aeronautics and Space Administration — Single crystal piezoelectric actuators are proposed to enable large stroke, high precision, shape control for cryogenic lightweight deployable membrane mirror...

  8. Viral RNAs are unusually compact.

    Directory of Open Access Journals (Sweden)

    Ajaykumar Gopal

    Full Text Available A majority of viruses are composed of long single-stranded genomic RNA molecules encapsulated by protein shells with diameters of just a few tens of nanometers. We examine the extent to which these viral RNAs have evolved to be physically compact molecules to facilitate encapsulation. Measurements of equal-length viral, non-viral, coding and non-coding RNAs show viral RNAs to have among the smallest sizes in solution, i.e., the highest gel-electrophoretic mobilities and the smallest hydrodynamic radii. Using graph-theoretical analyses we demonstrate that their sizes correlate with the compactness of branching patterns in predicted secondary structure ensembles. The density of branching is determined by the number and relative positions of 3-helix junctions, and is highly sensitive to the presence of rare higher-order junctions with 4 or more helices. Compact branching arises from a preponderance of base pairing between nucleotides close to each other in the primary sequence. The density of branching represents a degree of freedom optimized by viral RNA genomes in response to the evolutionary pressure to be packaged reliably. Several families of viruses are analyzed to delineate the effects of capsid geometry, size and charge stabilization on the selective pressure for RNA compactness. Compact branching has important implications for RNA folding and viral assembly.

  9. High precision optical finishing of lightweight silicon carbide aspheric mirror (United States)

    Kong, John; Young, Kevin


    Critical to the deployment of large surveillance optics into the space environment is the generation of high quality optics. Traditionally, aluminum, glass and beryllium have been used; however, silicon carbide becomes of increasing interest and availability due to its high strength. With the hardness of silicon carbide being similar to diamond, traditional polishing methods suffer from slow material removal rates, difficulty in achieving the desired figure and inherent risk of causing catastrophic damage to the lightweight structure. Rather than increasing structural capacity and mass of the substrate, our proprietary sub-aperture aspheric surface forming technology offers higher material removal rates (comparable to that of Zerodur or Fused Silica), a deterministic approach to achieving the desired figure while minimizing contact area and the resulting load on the optical structure. The technology performed on computer-controlled machines with motion control software providing precise and quick convergence of surface figure, as demonstrated by optically finishing lightweight silicon carbide aspheres. At the same time, it also offers the advantage of ideal pitch finish of low surface micro-roughness and low mid-spatial frequency error. This method provides a solution applicable to all common silicon carbide substrate materials, including substrates with CVD silicon carbide cladding, offered by major silicon carbide material suppliers. This paper discusses a demonstration mirror we polished using this novel technology. The mirror is a lightweight silicon carbide substrate with CVD silicon carbide cladding. It is a convex hyperbolic secondary mirror with 104mm diameter and approximately 20 microns aspheric departure from best-fit sphere. The mirror has been finished with surface irregularity of better than 1/50 wave RMS @632.8 nm and surface micro-roughness of under 2 angstroms RMS. The technology has the potential to be scaled up for manufacturing capabilities of

  10. Sputtering of sub-micrometer aluminum layers as compact, high-performance, light-weight current collector for supercapacitors (United States)

    Busom, J.; Schreiber, A.; Tolosa, A.; Jäckel, N.; Grobelsek, I.; Peter, N. J.; Presser, V.


    Supercapacitors are devices for rapid and efficient electrochemical energy storage and commonly employ carbon coated aluminum foil as the current collector. However, the thickness of the metallic foil and the corresponding added mass lower the specific and volumetric performance on a device level. A promising approach to drastically reduce the mass and volume of the current collector is to directly sputter aluminum on the freestanding electrode instead of adding a metal foil. Our work explores the limitations and performance perspectives of direct sputter coating of aluminum onto carbon film electrodes. The tight and interdigitated interface between the metallic film and the carbon electrode enables high power handling, exceeding the performance and stability of a state-of-the-art carbon coated aluminum foil current collector. In particular, we find an enhancement of 300% in specific power and 186% in specific energy when comparing aluminum sputter coated electrodes with conventional electrodes with Al current collectors.

  11. Compact, Lightweight Adsorber and Sabatier Reactor for CO2 Capture and Reduction for Consumable and Propellant Production (United States)

    Junaedi, Christian; Hawley, Kyle; Walsh, Dennis; Roychoudhury, Subir; Busby, Stacy A.; Abney, Morgan B.; Perry, Jay L.; Knox, James C.


    The utilization of CO2 to produce (or recycle) life support consumables, such as O2 and H2O, and to generate propellant fuels is an important aspect of NASA's concept for future, long duration planetary exploration. One potential approach is to capture and use CO2 from the Martian atmosphere to generate the consumables and propellant fuels. Precision Combustion, Inc. (PCI), with support from NASA, continues to develop its regenerable adsorber technology for capturing CO2 from gaseous atmospheres (for cabin atmosphere revitalization and in-situ resource utilization applications) and its Sabatier reactor for converting CO2 to methane and water. Both technologies are based on PCI's Microlith(R) substrates and have been demonstrated to reduce size, weight, and power consumption during CO2 capture and methanation process. For adsorber applications, the Microlith substrates offer a unique resistive heating capability that shows potential for short regeneration time and reduced power requirements compared to conventional systems. For the Sabatier applications, the combination of the Microlith substrates and durable catalyst coating permits efficient CO2 methanation that favors high reactant conversion, high selectivity, and durability. Results from performance testing at various operating conditions will be presented. An effort to optimize the Sabatier reactor and to develop a bench-top Sabatier Development Unit (SDU) will be discussed.

  12. An extremely lightweight fingernail worn prosthetic interface device (United States)

    Yetkin, Oguz; Ahluwalia, Simranjit; Silva, Dinithi; Kasi-Okonye, Isioma; Volker, Rachael; Baptist, Joshua R.; Popa, Dan O.


    Upper limb prosthetics are currently operated using several electromyography sensors mounted on an amputee's residual limb. In order for any prosthetic driving interface to be widely adopted, it needs to be responsive, lightweight, and out of the way when not being used. In this paper we discuss the possibility of replacing such electrodes with fingernail optical sensor systems mounted on the sound limb. We present a prototype device that can detect pinch gestures and communicate with the prosthetic system. The device detects the relative position of fingers to each other by measuring light transmitted via tissue. Applications are not limited to prosthetic control, but can be extended to other human-machine interfaces.

  13. APE: Authenticated Permutation-Based Encryption for Lightweight Cryptography

    DEFF Research Database (Denmark)

    Andreeva, Elena; Bilgin, Begül; Bogdanov, Andrey


    of cryptographic schemes actually require the nonce assumption for their security. In this paper, we propose APE as the first permutation-based authenticated encryption scheme that is resistant against nonce misuse. We formally prove that APE is secure, based on the security of the underlying permutation....... To decrypt, APE processes the ciphertext blocks in reverse order, and uses inverse permutation calls. APE therefore requires a permutation that is both efficient for forward and inverse calls. We instantiate APE with the permutations of three recent lightweight hash function designs: Quark, Photon...

  14. Lightweight Radioisotope Heater Unit (LWRHU) production for the Cassini mission

    Energy Technology Data Exchange (ETDEWEB)

    Rinehart, G.H.


    The Lightweight Radioisotope Heater Unit (LWRHU) is a {sup 238}PuO{sub 2} fueled heat source designed to provide a thermal watt of power for space missions. The LWRHU will be used to maintain the temperature of various components on the spacecraft at the required level. The heat source consists of a {sup 238}PuO{sub 2} fuel pellet, a Pt-30Rh capsule, a pyrolytic graphite insulator, and a woven graphite aeroshell assembly. Los Alamos has fabricated 180 heater units, which will be used on the Cassini mission. This report summarizes the specifications, fabrication processes, and production data for the heat sources fabricated at Los Alamos.

  15. Accuracy of Dynamic and Acoustic Analysis of Lightweight Panel Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Dickow, Kristoffer Ahrens; Andersen, Lars Vabbersgaard


    in such buildings is important. In the lowfrequency range, prediction of sound and vibration in building structures may be achieved by finite-element analysis (FEA). The aim of this paper is to compare the two commercial codes ABAQUS and ANSYS for FEA of an acoustic-structural coupling in a timber lightweight panel...... structure. For this purpose, modal analyses are carried out employing a fully coupled model of sound waves within an acoustic medium and vibrations in the structural part. The study concerns the frequency range 50–250 Hz....

  16. Vibrations in a Multi-Storey Lightweight Building Structure

    DEFF Research Database (Denmark)

    Andersen, Lars Vabbersgaard; Kirkegaard, Poul Henning


    This paper provides a quantification of the changes in vibration level that can be expected in a lightweight multi-storey wooden building due to reduced connection stiffness or added nonstructural mass. Firstly, the impact of changes in the floor-to-wall connections is examined. Secondly, a study...... is performed regarding variations of the vibration level due to different placements of nonstructural mass inside the building. The analyses are carried out by means of a modular three-dimensional finite-element model. Each floor and wall panel is modelled in high detail, including door and window openings...

  17. Light-weight spherical mirrors for Cherenkov detectors

    CERN Document Server

    Cisbani, E; Colilli, S; Crateri, R; Cusanno, F; De Leo, R; Fratoni, R; Frullani, S; Garibaldi, F; Giuliani, F; Gricia, M; Iodice, M; Iommi, R; Lagamba, L; Lucentini, M; Mostarda, A; Nappi, E; Pierangeli, L; Santavenere, F; Urciuoli, G M; Vernin, P


    Light-weight spherical mirrors have been appositely designed and built for the gas threshold Cherenkov detectors of the two Hall A spectrometers. The mirrors are made of a 1 mm thick aluminized plexiglass sheet, reinforced by a rigid backing consisting of a phenolic honeycomb sandwiched between two carbon fiber mats epoxy glued. The produced mirrors have a thickness equivalent to 0.55% of radiation length, and an optical slope error of about 5.5 mrad. These characteristics make these mirrors suitable for the implementation in Cherenkov threshold detectors. Ways to improve the mirror features are also discussed in view of their possible employment in RICH detectors.

  18. Laser based metal and plastics joining for lightweight design (United States)

    Kahmann, Max; Quentin, Ulf; Kirchhoff, Marc; Brockmann, Rüdiger; Löffler, Klaus


    One of the most important issues in automotive industry is lightweight design, especially since the CO2 emission of new cars has to be reduced by 2020. Plastic and fiber reinforced plastics (e.g. CFRP and GFRP) receive besides new manufacturing methods and the employment of high-strength steels or non-ferrous metals increasing interest. Especially the combination of different materials such as metals and plastics to single components exhausts the entire potential on weight reduction. This article presents an approach based on short laser pulses to join such dissimilar materials in industrial applications.

  19. A lightweight feedback-controlled microdrive for chronic neural recordings (United States)

    Jovalekic, A.; Cavé-Lopez, S.; Canopoli, A.; Ondracek, J. M.; Nager, A.; Vyssotski, A. L.; Hahnloser, R. H. R.


    Objective. Chronic neural recordings have provided many insights into the relationship between neural activity and behavior. We set out to develop a miniaturized motorized microdrive that allows precise electrode positioning despite possibly unreliable motors. Approach. We designed a feedback-based motor control mechanism. It contains an integrated position readout from an array of magnets and a Hall sensor. Main results. Our extremely lightweight (feedback-based microdrive control requires little extra size and weight, suggesting that such control can be incorporated into more complex multi-electrode designs.

  20. Cryogenic optical tests of a lightweight HIP beryllium mirror (United States)

    Melugin, Ramsey K.; Miller, Jacob H.; Young, J. A.; Howard, Steven D.; Pryor, G. Mark

    Five interferometric tests were conducted at cryogenic temperatures on a lightweight, 50 cm diameter, hot isostatic pressed (HIP) beryllium mirror in the Ames Research Center (ARC) Cryogenic Optics Test Facility. The purpose of the tests was to determine the stability of the mirror's figure when cooled to cryogenic temperatures. Test temperatures ranged from room ambient to 8 K. One cycle to 8 K and five cycles to 80 K were performed. Optical and thermal test methods are described. Data is presented to show the amount of cryogenic distortion and hysteresis present in the mirror when measured with an earlier, Shack interferometer, and with a newly-acquired, phase-measuring interferometer.

  1. Lightweight Aggregate Concrete. The materials in the precast elements

    DEFF Research Database (Denmark)

    Goltermann, Per; Larsen, Henning; Ingholt, N.U.


    The precast lightweight aggregate concrete (LAC) elements are used extensively in Denmark, where the use of precast elements domonates the building structures. Similar elements are used in other parts of Nothern Europe, which have lead to development of an European standard for precast LAC elements...... of LAC with open structure (prEN1520).The test results have shown that the formulas in prEN1520's revision are fairly correct and lead to slightly conservative estimates of the modulus of elasticity and flexural strength....

  2. Lightweight rotor design by optimal spar cap offset (United States)

    Croce, A.; Sartori, L.; Lunghini, M. S.; Clozza, L.; Bortolotti, P.; Bottasso, C. L.


    Bend-twist coupling behavior is induced in a blade by displacing the suction side spar cap towards the leading edge, and the pressure side one in the opposite direction. Additional couplings are introduced by rotating the spar cap fibers. The structural configuration of the blade is optimized using an automated design environment. The resulting blade shows significant benefits in terms of mass and loads when compared to the baseline uncoupled one. Finally, the lightweight design concept is used to increase the rotor size, resulting in a larger energy yield for the same hub loads.

  3. Ultra lightweight mirror performance at 8 degrees kelvin (United States)

    Crowe, D. A.; Melugin, R. K.; Miller, J. H.


    Earlier work funded by DARPA, evaluating the optical stability of a 0.5-m ultra-lightweight, frit-bonded, fused silica mirror, is extended from the previous 100 deg K specification down to 8 deg K. The thermal stability is excellent and comparable to that for conventional fusion and solid mirrors. The total mirror change of 0.10 lambda rms (lambda = 0.6328 microns) meets the needs of most IR systems. Thermal elastic quilting is excellent (0.008 lambda). Ames Research Center and Kodak data evaluations, done independently, are in very good agreement.

  4. The United Nations Global Compact

    DEFF Research Database (Denmark)

    Rasche, Andreas; Waddock, Sandra; McIntosh, Malcolm


    This article reviews the interdisciplinary literature on the UN Global Compact. The review identifies three research perspectives, which scholars have used to study the UN Global Compact so far: a historical perspective discussing the Global Compact in the context of UN-business relations......, an operational perspective discussing the composition and impact of its participants, as well as a governance perspective discussing the constraints and opportunities of the initiative as an institutionalized arena for addressing global governance gaps. The authors contrast these three perspectives and identify...... key empirical as well as conceptual scholarly contributions. The remainder of this article contains focused summaries of the articles selected for this Special Issue. All articles are introduced and evaluated against the background of the three research perspectives....

  5. Development of the RF cavity for the SKKUCY-9 compact cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Seungwook; Lee, Jongchul [Department of Energy Science, Sungkyunkwan University, 2066, Seobu-Ro, Jangan-Gu, Suwon-si, Gyeonggi-do (Korea, Republic of); LEE, Byeong-No [Radiation Equipment Research Division, Korea Atomic Energy Research Institute, 111, Daedeok-daero 989 Beon-gil, Yuseong-gu, Daejeon (Korea, Republic of); Ha, Donghyup; Namgoong, Ho [College of Information & Communication Engineering, Sungkyunkwan University, 2066, Seobu-Ro, Jangan-Gu, Suwon-si, Gyeonggi-do (Korea, Republic of); Chai, Jongseo, E-mail: [College of Information & Communication Engineering, Sungkyunkwan University, 2066, Seobu-Ro, Jangan-Gu, Suwon-si, Gyeonggi-do (Korea, Republic of)


    A 9 MeV compact cyclotron, named SKKUCY-9, for a radiopharmaceutical compound especially fludeoxyglucose (FDG) production for a positron emission tomography (PET) machine was developed at Sungkyunkwan University. H{sup −} ions which are produced from a Penning Ionization Gauge(PIG) ion source, travel through a normal conducting radio frequency (RF) cavity which operates at 83.2 MHz for an acceleration and electro-magnet for a beam focusing until the ions acquire energy of about 9 MeV. For installation at a small local hospital, our SKKUCY-9 cyclotron is developed to be compact and light-weight, comparable to conventional medical purpose cyclotrons. For compactness, we adapted a deep valley and large angle hill type for the electro-magnet design. Normally a RF cavity is installed inside of the empty space of the magnet valley region, which is extremely small in our case. We faced problems such as difficulties of installing the RF cavity, low Q-value. Despite of those difficulties, a compact RF cavity and its system including a RF power coupler to feed amplified RF power to the RF cavity and a fine tuner to compensate RF frequency variations was successfully developed and tested.

  6. Professional Windows Embedded Compact 7

    CERN Document Server

    Phung, Samuel; Joubert, Thierry; Hall, Mike


    Learn to program an array of customized devices and solutions As a compact, highly efficient, scalable operating system, Windows Embedded Compact 7 (WEC7) is one of the best options for developing a new generation of network-enabled, media-rich, and service-oriented devices. This in-depth resource takes you through the benefits and capabilities of WEC7 so that you can start using this performance development platform today. Divided into several major sections, the book begins with an introduction and then moves on to coverage of OS design, application development, advanced application developm

  7. Compact monolithic capacitive discharge unit (United States)

    Roesler, Alexander W.; Vernon, George E.; Hoke, Darren A.; De Marquis, Virginia K.; Harris, Steven M.


    A compact monolithic capacitive discharge unit (CDU) is disclosed in which a thyristor switch and a flyback charging circuit are both sandwiched about a ceramic energy storage capacitor. The result is a compact rugged assembly which provides a low-inductance current discharge path. The flyback charging circuit preferably includes a low-temperature co-fired ceramic transformer. The CDU can further include one or more ceramic substrates for enclosing the thyristor switch and for holding various passive components used in the flyback charging circuit. A load such as a detonator can also be attached directly to the CDU.

  8. Raytheon's next generation compact inline cryocooler architecture

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, B. R.; Bellis, L.; Ellis, M. J.; Conrad, T. [Raytheon Space and Airborne Systems, 2000 E. El Segundo Blvd., El Segundo, CA 90245 (United States)


    Since the 1970s, Raytheon has developed, built, tested and integrated high performance cryocoolers. Our versatile designs for single and multi-stage cryocoolers provide reliable operation for temperatures from 10 to 200 Kelvin with power levels ranging from 50 W to nearly 600 W. These advanced cryocoolers incorporate clearance seals, flexure suspensions, hermetic housings and dynamic balancing to provide long service life and reliable operation in all relevant environments. Today, sensors face a multitude of cryocooler integration challenges such as exported disturbance, efficiency, scalability, maturity, and cost. As a result, cryocooler selection is application dependent, oftentimes requiring extensive trade studies to determine the most suitable architecture. To optimally meet the needs of next generation passive IR sensors, the Compact Inline Raytheon Stirling 1-Stage (CI-RS1), Compact Inline Raytheon Single Stage Pulse Tube (CI-RP1) and Compact Inline Raytheon Hybrid Stirling/Pulse Tube 2-Stage (CI-RSP2) cryocoolers are being developed to satisfy this suite of requirements. This lightweight, compact, efficient, low vibration cryocooler combines proven 1-stage (RS1 or RP1) and 2-stage (RSP2) cold-head architectures with an inventive set of warm-end mechanisms into a single cooler module, allowing the moving mechanisms for the compressor and the Stirling displacer to be consolidated onto a common axis and in a common working volume. The CI cryocooler is a significant departure from the current Stirling cryocoolers in which the compressor mechanisms are remote from the Stirling displacer mechanism. Placing all of the mechanisms in a single volume and on a single axis provides benefits in terms of package size (30% reduction), mass (30% reduction), thermodynamic efficiency (>20% improvement) and exported vibration performance (≤25 mN peak in all three orthogonal axes at frequencies from 1 to 500 Hz). The main benefit of axial symmetry is that proven balancing

  9. a Light-Weight Laser Scanner for Uav Applications (United States)

    Tommaselli, A. M. G.; Torres, F. M.


    Unmanned Aerial Vehicles (UAV) have been recognized as a tool for geospatial data acquisition due to their flexibility and favourable cost benefit ratio. The practical use of laser scanning devices on-board UAVs is also developing with new experimental and commercial systems. This paper describes a light-weight laser scanning system composed of an IbeoLux scanner, an Inertial Navigation System Span-IGM-S1, from Novatel, a Raspberry PI portable computer, which records data from both systems and an octopter UAV. The performance of this light-weight system was assessed both for accuracy and with respect to point density, using Ground Control Points (GCP) as reference. Two flights were performed with the UAV octopter carrying the equipment. In the first trial, the flight height was 100 m with six strips over a parking area. The second trial was carried out over an urban park with some buildings and artificial targets serving as reference Ground Control Points. In this experiment a flight height of 70 m was chosen to improve target response. Accuracy was assessed based on control points the coordinates of which were measured in the field. Results showed that vertical accuracy with this prototype is around 30 cm, which is acceptable for forest applications but this accuracy can be improved using further refinements in direct georeferencing and in the system calibration.


    Directory of Open Access Journals (Sweden)

    A. M. G. Tommaselli


    Full Text Available Unmanned Aerial Vehicles (UAV have been recognized as a tool for geospatial data acquisition due to their flexibility and favourable cost benefit ratio. The practical use of laser scanning devices on-board UAVs is also developing with new experimental and commercial systems. This paper describes a light-weight laser scanning system composed of an IbeoLux scanner, an Inertial Navigation System Span-IGM-S1, from Novatel, a Raspberry PI portable computer, which records data from both systems and an octopter UAV. The performance of this light-weight system was assessed both for accuracy and with respect to point density, using Ground Control Points (GCP as reference. Two flights were performed with the UAV octopter carrying the equipment. In the first trial, the flight height was 100 m with six strips over a parking area. The second trial was carried out over an urban park with some buildings and artificial targets serving as reference Ground Control Points. In this experiment a flight height of 70 m was chosen to improve target response. Accuracy was assessed based on control points the coordinates of which were measured in the field. Results showed that vertical accuracy with this prototype is around 30 cm, which is acceptable for forest applications but this accuracy can be improved using further refinements in direct georeferencing and in the system calibration.

  11. Efficient Hardware Implementation of the Lightweight Block Encryption Algorithm LEA

    Directory of Open Access Journals (Sweden)

    Donggeon Lee


    Full Text Available Recently, due to the advent of resource-constrained trends, such as smartphones and smart devices, the computing environment is changing. Because our daily life is deeply intertwined with ubiquitous networks, the importance of security is growing. A lightweight encryption algorithm is essential for secure communication between these kinds of resource-constrained devices, and many researchers have been investigating this field. Recently, a lightweight block cipher called LEA was proposed. LEA was originally targeted for efficient implementation on microprocessors, as it is fast when implemented in software and furthermore, it has a small memory footprint. To reflect on recent technology, all required calculations utilize 32-bit wide operations. In addition, the algorithm is comprised of not complex S-Box-like structures but simple Addition, Rotation, and XOR operations. To the best of our knowledge, this paper is the first report on a comprehensive hardware implementation of LEA. We present various hardware structures and their implementation results according to key sizes. Even though LEA was originally targeted at software efficiency, it also shows high efficiency when implemented as hardware.

  12. Thermal performance of lightweight construction systems: Performance of `Solar One`

    Energy Technology Data Exchange (ETDEWEB)

    Hyde, R. [Queensland Univ., St. Lucia, QLD (Australia)


    Research is currently under way to asses the thermal performance of building which use new lightweight systems of construction. In particular, comparison is made between expected performance and performance found in buildings. This paper outlines the basic direction of the research and examines one particular building case study, that of Solar One. Solar One is located at Mount Coolum to the north of Brisbane on the Sunshine Coast in Queensland. This building is designed based on climatic criteria and departs from the conventional timber framed house in a number of respects. The important difference in this building is that it is a hybrid construction. Mass is used for some walls and ground floor slab and timber framing with fibre-cement for other walls. The research demonstrates to what extent the building performs to characteristics of lightweight construction systems and to what extent it performs as a heavyweight system. Focus is placed on the thermal response of the building. Conclusions reached from this case study suggest that the building does not match expected patterns of thermal response particularly in winter, there appears to be a complex heat interchange process showing clear benefits for the hybrid construction. (author). 10 figs., 4 refs.

  13. A Lightweight Structure Redesign Method Based on Selective Laser Melting

    Directory of Open Access Journals (Sweden)

    Li Tang


    Full Text Available The purpose of this paper is to present a new design method of lightweight parts fabricated by selective laser melting (SLM based on the “Skin-Frame” and to explore the influence of fabrication defects on SLM parts with different sizes. Some standard lattice parts were designed according to the Chinese GB/T 1452-2005 standard and manufactured by SLM. Then these samples were tested in an MTS Insight 30 compression testing machine to study the trends of the yield process with different structure sizes. A set of standard cylinder samples were also designed according to the Chinese GB/T 228-2010 standard. These samples, which were made of iron-nickel alloy (IN718, were also processed by SLM, and then tested in the universal material testing machine INSTRON 1346 to obtain their tensile strength. Furthermore, a lightweight redesigned method was researched. Then some common parts such as a stopper and connecting plate were redesigned using this method. These redesigned parts were fabricated and some application tests have already been performed. The compression testing results show that when the minimum structure size is larger than 1.5 mm, the mechanical characteristics will hardly be affected by process defects. The cylinder parts were fractured by the universal material testing machine at about 1069.6 MPa. These redesigned parts worked well in application tests, with both the weight and fabrication time of these parts reduced more than 20%.

  14. Coating Thin Mirror Segments for Lightweight X-ray Optics (United States)

    Chan, Kai-Wing; Sharpe, Marton V.; Zhang, William; Kolosc, Linette; Hong, Melinda; McClelland, Ryan; Hohl, Bruce R.; Saha, Timo; Mazzarellam, James


    Next generations lightweight, high resolution, high throughput optics for x-ray astronomy requires integration of very thin mirror segments into a lightweight telescope housing without distortion. Thin glass substrates with linear dimension of 200 mm and thickness as small as 0.4 mm can now be fabricated to a precision of a few arc-seconds for grazing incidence optics. Subsequent implementation requires a distortion-free deposition of metals such as iridium or platinum. These depositions, however, generally have high coating stresses that cause mirror distortion. In this paper, we discuss the coating stress on these thin glass mirrors and the effort to eliminate their induced distortion. It is shown that balancing the coating distortion either by coating films with tensile and compressive stresses, or on both sides of the mirrors is not sufficient. Heating the mirror in a moderately high temperature turns out to relax the coated films reasonably well to a precision of about a second of arc and therefore provide a practical solution to the coating problem.

  15. Lightweight storage and overlay networks for fault tolerance.

    Energy Technology Data Exchange (ETDEWEB)

    Oldfield, Ron A.


    The next generation of capability-class, massively parallel processing (MPP) systems is expected to have hundreds of thousands to millions of processors, In such environments, it is critical to have fault-tolerance mechanisms, including checkpoint/restart, that scale with the size of applications and the percentage of the system on which the applications execute. For application-driven, periodic checkpoint operations, the state-of-the-art does not provide a scalable solution. For example, on today's massive-scale systems that execute applications which consume most of the memory of the employed compute nodes, checkpoint operations generate I/O that consumes nearly 80% of the total I/O usage. Motivated by this observation, this project aims to improve I/O performance for application-directed checkpoints through the use of lightweight storage architectures and overlay networks. Lightweight storage provide direct access to underlying storage devices. Overlay networks provide caching and processing capabilities in the compute-node fabric. The combination has potential to signifcantly reduce I/O overhead for large-scale applications. This report describes our combined efforts to model and understand overheads for application-directed checkpoints, as well as implementation and performance analysis of a checkpoint service that uses available compute nodes as a network cache for checkpoint operations.

  16. Concept for lightweight spaced-based deposition technology

    Energy Technology Data Exchange (ETDEWEB)

    Fulton, Michael; Anders, Andre


    In this contribution we will describe a technology path to very high quality coatings fabricated in the vacuum of space. To accomplish the ambitious goals set out in NASA's Lunar-Mars proposal, advanced thin-film deposition technology will be required. The ability to deposit thin-film coatings in the vacuum of lunar-space could be extremely valuable for executing this new space mission. Developing lightweight space-based deposition technology (goal:<300 g, including power supply) will enable the future fabrication and repair of flexible large-area space antennae and fixed telescope mirrors for lunar-station observatories. Filtered Cathodic Arc (FCA) is a proven terrestrial energetic thin-film deposition technology that does not need any processing gas but is well suited for ultra-high vacuum operation. Recently, miniaturized cathodic arcs have already been developed and considered for space propulsion. It is proposed to combine miniaturized pulsed FCA technology and robotics to create a robust, enabling space-based deposition system for the fabrication, improvement, and repair of thin films, especially of silver and aluminum, on telescope mirrors and eventually on large area flexible substrates. Using miniature power supplies with inductive storage, the typical low-voltage supply systems used in space are adequate. It is shown that high-value, small area coatings are within the reach of existing technology, while medium and large area coatings are challenging in terms of lightweight technology and economics.

  17. Apply lightweight recognition algorithms in optical music recognition (United States)

    Pham, Viet-Khoi; Nguyen, Hai-Dang; Nguyen-Khac, Tung-Anh; Tran, Minh-Triet


    The problems of digitalization and transformation of musical scores into machine-readable format are necessary to be solved since they help people to enjoy music, to learn music, to conserve music sheets, and even to assist music composers. However, the results of existing methods still require improvements for higher accuracy. Therefore, the authors propose lightweight algorithms for Optical Music Recognition to help people to recognize and automatically play musical scores. In our proposal, after removing staff lines and extracting symbols, each music symbol is represented as a grid of identical M ∗ N cells, and the features are extracted and classified with multiple lightweight SVM classifiers. Through experiments, the authors find that the size of 10 ∗ 12 cells yields the highest precision value. Experimental results on the dataset consisting of 4929 music symbols taken from 18 modern music sheets in the Synthetic Score Database show that our proposed method is able to classify printed musical scores with accuracy up to 99.56%.

  18. Sustainability assessment of a lightweight biomimetic ceiling structure. (United States)

    Antony, Florian; Grießhammer, Rainer; Speck, Thomas; Speck, Olga


    An intensive and continuous debate centres on the question of whether biomimetics has a specific potential to contribute to sustainability. In the context of a case study, the objective of this paper is to contribute to this debate by presenting the first systematic approach to assess the sustainability of a complex biomimetic product. The object of inquiry is a lecture hall's ribbed slab. Based on criteria suggested by the Association of German Engineers (VDI), it has been verified that the slab has been correctly defined as biomimetic. Moreover, a systematic comparative product sustainability assessment has been carefully carried out. For purposes of comparison, estimated static calculations have been performed for conceivable current state-of-the-art lightweight ceiling structures. Alternative options are a hollow article slab and a pre-stressed flat slab. Besides a detailed benefit analysis and a discussion of social effects, their costs have also been compared. A particularly detailed life cycle assessment on the respective environmental impacts has also been performed. Results show that the biomimetic ribbed slab built in the 1960s is able to keep up with the current state-of-the-art lightweight solutions in terms of sustainability. These promising results encourage a systematic search for a broad range of sustainable biomimetic solutions.

  19. Lightweight C/SiC mirrors for space application (United States)

    Zhou, Hao; Zhang, Chang-rui; Cao, Ying-bin; Zhou, Xin-gui


    Challenges in high resolution space telescopes have led to the desire to create large primary mirror apertures. Ceramic mirrors and complex structures are becoming more important for high precision lightweight optical applications in adverse environments. Carbon-fiber reinforced silicon carbide (C/SiC) has shown great potential to be used as mirror substrate. This material has a high stiffness to weight ratio, dimensional stability from ambient to cryo temperatures, and thermal conductivity, low thermal expansion as well. These properties make C/SiC very attractive for a variety of applications in precision optical structures, especially when considering space-borne application. In this paper, lightweight C/SiC mirror prepared for a scan mirror of a high resolution camera is presented. The manufacturing of C/SiC mirror starts with a porous rigid felt made of short chopped carbon fibers. The fibers are molded with phenolic resin under pressure to form a carbon fiber reinforced plastic blank, followed by a pyrolization process by which the phenolic resin reacts to a carbon matrix. The C/C-felt can be machined by standard computer controlled milling techniques to any virtual shape. This is one of the most significant advantages of this material, as it drastically reduces the making costs and enables the manufacture of truly ultra-lightweight mirrors, reflectors and structures. Upon completion of milling, the C/C-felt preform is mounted in a high-temperature furnace together with silicon and heated under vacuum condition to 1500°C at which the silicon changes into liquid phase. Subsequently, the molten silicon is infiltrated into the porous preform under capillary forces to react with carbon matrix and the surfaces of the carbon fibers to form a density C/SiC substrate. The C/SiC material retains the preform shape to within a tight tolerance after sintering means the ceramization process is a nearly net shaping process. Reactive melt infiltrated C/SiC, followed by

  20. Wet-spinning of continuous montmorillonite-graphene fibers for fire-resistant lightweight conductors. (United States)

    Fang, Bo; Peng, Li; Xu, Zhen; Gao, Chao


    All-inorganic fibers composed of neat 2D crystals possessing fascinating performance (e.g., alternately stacking layers, high mechanical strength, favorable electrical conductivity, and fire-resistance) are discussed in detail. We developed a wet-spinning assmebly strategy to achieve continuous all-inorganic fibers of montmorillonite (MMT) nanoplatelets by incorporation of a graphene oxide (GO) liquid crystal (LC) template at a rate of 9 cm/s, and the templating role of GO LC is confirmed by in situ confocal laser scanning microscopy and polarized optical microscopy inspections. After protofibers underwent thermal reduction, the obtained binary complex fibers composed of neat 2D crystals integrate the outstanding fire-retardance of MMT nanoplatelets and the excellent conductivity of graphene nanosheets. High-resolution transmission electron microscopy and scanning electron microscope observations reveal the microstructures of fibers with compactly stacking layers. MMT-graphene fibers show increaing tensile strengths (88-270 MPa) and electrical conductivities (130-10500 S/m) with increasing graphene fraction. MMT-graphene (10/90) fibers are used as fire-resistant (bearing temperature in air: 600-700 °C), lightweight (ρ resistance of MMT-graphene fibers to the armor-like protection of MMT layers, which could shield graphene layers from the action of oxidative etching. The composite fibers worked well as fire-resistant conductors when being heated to glowing red by an alcohol lamp. Our GO LC-templating wet-spinning strategy may also inspire the continuous assembly of other layered crystals into high-performance composite fibers.

  1. DNA compaction by nonbinding macromolecules

    NARCIS (Netherlands)

    Vries, de R.J.


    Compaction of DNA by nonbinding macromolecules such as uncharged flexible polymer chains and negatively charged globular proteins is thought to have various applications in biophysics, for example in the formation of a nucleoid structure in bacteria. A simple experimental model that has been very we

  2. Fuzzy Soft Compact Topological Spaces

    Directory of Open Access Journals (Sweden)

    Seema Mishra


    Full Text Available In this paper, we have studied compactness in fuzzy soft topological spaces which is a generalization of the corresponding concept by R. Lowen in the case of fuzzy topological spaces. Several basic desirable results have been established. In particular, we have proved the counterparts of Alexander’s subbase lemma and Tychonoff theorem for fuzzy soft topological spaces.


    Institute of Scientific and Technical Information of China (English)

    H. Vaezi; S. F. Rzaev


    In this article we consider the generalized shift operator defined by(Sh.f)(g) = ∫Gf (tut-1g)dton compact group G and by help of this operator we define "Spherical" modulus of continuity. So we proveStechkin and Jackson type theorems.

  4. The Compact Project: Final Report. (United States)

    National Alliance of Business, Inc., Washington, DC.

    The National Alliance of Business (NAB) surveyed the 12 sites that participated in the Compact Project to develop and implement programs of business-education collaboration. NAB studied start-up activities, key players, conditions for collaboration, accomplishments, challenges, and future plans. Program outcomes indicated that building successful…

  5. Compact Photon Source Conceptual Design

    Energy Technology Data Exchange (ETDEWEB)

    Degtyarenko, Pavel V. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Wojtsekhowski, Bogdan B. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)


    We describe options for the production of an intense photon beam at the CEBAF Hall D Tagger facility, needed for creating a high-quality secondary K 0 L delivered to the Hall D detector. The conceptual design for the Compact Photon Source apparatus is presented.

  6. 78 FR 43142 - Lightweight Thermal Paper From the People's Republic of China: Rescission of Antidumping Duty... (United States)


    ... High-Tech Co., Ltd.; Henan Province Jianghe Paper Co., Ltd., Jianghe Paper Co., Ltd., and JHT Paper... wrap, a non-subject product) and 4811.90.8040 (for ``other'' including lightweight thermal paper... product) and 4811.90.9090 (for ``other,'' including lightweight thermal paper). \\8\\ As of January 1,...

  7. 46 CFR 170.200 - Estimated lightweight vertical center of gravity. (United States)


    ... 46 Shipping 7 2010-10-01 2010-10-01 false Estimated lightweight vertical center of gravity. 170... Centers of Gravity § 170.200 Estimated lightweight vertical center of gravity. (a) Each tank vessel that... calculations required by §§ 170.170 and 172.065, the vertical center of gravity of a tank vessel in...

  8. 77 FR 73615 - Lightweight Thermal Paper From Germany; Preliminary Results of Antidumping Duty Administrative... (United States)


    ...] Lightweight Thermal Paper From Germany; Preliminary Results of Antidumping Duty Administrative Review; 2010... duty order on lightweight thermal paper (LWTP) from Germany for the period November 1, 2010, through... Germany and the People's Republic of China, 73 FR 70959 (November 24, 2008) (Orders). Methodology...

  9. 78 FR 23220 - Lightweight Thermal Paper From Germany: Final Results of Antidumping Duty Administrative Review... (United States)


    ... International Trade Administration Lightweight Thermal Paper From Germany: Final Results of Antidumping Duty... from Germany.\\1\\ The period of review (POR) is November 1, 2010, through October 31, 2011. We invited... in the section entitled ``Final Results of Review.'' \\1\\ See Lightweight Thermal Paper from...

  10. Analysis and trade-off studies of large lightweight mirror structures. [large space telescope (United States)

    Soosaar, K.; Grin, R.; Ayer, F.


    A candidate mirror, hexagonally lightweighted, is analyzed under various loadings using as complete a procedure as possible. Successive simplifications are introduced and compared to an original analysis. A model which is a reasonable compromise between accuracy and cost is found and is used for making trade-off studies of the various structural parameters of the lightweighted mirror.

  11. Lightweight ZERODUR®: A Candidate Material for Affordable Future UVOIR Space Telescopes of All Apertures (United States)

    Hull, Anthony B.; Westerhoff, T.; Leys, A.


    Recent Developments now make available for spaceborne applications highly lightweighted mirrors in ZERODUR®, regarded to be the “gold standard” material for thermal stability. ZERODUR® has flown on over 30 missions, including two great observatories, but not previously to this high degree of lightweighting. Now highly lightweighted mirror substrates can be made from a single billet of low expansion glass which exhibits remarkably low thermal expansion, anisotropy and inhomogeneity. This staility has the potential to simplify every aspect of a mission payload cost. A 1.2m open-back isogrid lightweighted mirror substrate has been made by SCHOTT exhibiting 88% lightweighting and a first Eigenfrequency over 200Hz. Also a recently made 0.3m isogrid lightweighted mirror exhibits ribs thinner than 0.9mm. Mirror or mirror segment substrates can be cost-effectively manufactured from monolithic blanks in apertures as small as 0.3m aperture to over 4m aperture (until recently SCHOTT maintained a line to make 8m ZERODUR® billets). We will describe this technology, the attributes of isogrid lightweighted mirror blanks, and the relevance of this material and manufacturing approach to upcoming UVOIR missions from suborbital to Explorer class to next generation Great Observatory. Lightweight ZERODUR® supports optical telescope systems requiring great stability, even in the presence of payload and scene thermal perturbations. Furthermore, mirrors or mirror segments made with the approach described can be made to remarkably short schedule, cost effectively and with little risk.

  12. On sequential countably compact topological semigroups

    CERN Document Server

    Gutik, Oleg V; Repovš, Dušan


    We study topological and algebraic properties of sequential countably compact topological semigroups similar to compact topological semigroups. We prove that a sequential countably compact topological semigroup does not contain the bicyclic semigroup. Also we show that the closure of a subgroup in a sequential countably compact topological semigroup is a topological group, that the inversion in a Clifford sequential countably compact topological semigroup is continuous and we prove the analogue of the Rees-Suschkewitsch Theorem for simple regular sequential countably compact topological semigroups.

  13. Analysis of lightweight gases by quadrupole ion trap mass spectrometry for the safety of the American Space Shuttle program (United States)

    Ottens, Andrew Keith

    The quadrupole ion trap mass spectrometer (QITMS) was patented nearly 50 years ago, when it was proposed for trace analysis of lightweight gas mixtures. Though a commercial success, QITMS has been used with analytes of ever-increasing size. We evaluated QITMS for quantifying lightweight gas mixtures with the performance compared to other mass analyzer technologies. The National Aeronautics and Space Administration (NASA) uses mass spectrometers to monitor the amount of hydrogen, helium, oxygen, and argon in the nitrogen-purged Space Shuttle. The explosive hazard of the cryogenic hydrogen and oxygen used to propel the Space Shuttle makes leak detection imperative. The two present-day leak detectors are remotely located because of their large size and sensitivity to vibration. Analysis is delayed by up to 45 s, and only two samples can be monitored simultaneously. In 2000, NASA initiated the Advanced Hazardous Gas Detection project to develop a compact, rugged, and fast mass spectrometer to be placed in multiple locations next to the Space Shuttle to provide real-time analysis with increased redundancy. The QITMS instrumentation was modified specifically for this application. The RF drive frequency was increased to 2.5 MHz to adequately trap lightweight hydrogen and helium ions. Internal ionization was preferred for use without a collision gas, along with an open source configuration that provided rapid sample replacement. The modern electronics incorporated were controlled by customized software. Analytes were found to react rapidly with abundant background gases. The QITMS operating conditions were optimized to minimize negative effects of ion-molecule reactions while maximizing analytical performance. A custom segmented scan function was developed with a total scan time of 14 ms, averaging 70 scans per data point at the required 1 Hz update rate. The QITMS met requirements for detection limits, accuracy, precision, response time, and recovery time. The linear

  14. Compaction and relaxation of biofilms

    KAUST Repository

    Valladares Linares, R.


    Operation of membrane systems for water treatment can be seriously hampered by biofouling. A better characterization of biofilms in membrane systems and their impact on membrane performance may help to develop effective biofouling control strategies. The objective of this study was to determine the occurrence, extent and timescale of biofilm compaction and relaxation (decompaction), caused by permeate flux variations. The impact of permeate flux changes on biofilm thickness, structure and stiffness was investigated in situ and non-destructively with optical coherence tomography using membrane fouling monitors operated at a constant crossflow velocity of 0.1 m s−1 with permeate production. The permeate flux was varied sequentially from 20 to 60 and back to 20 L m−2 h−1. The study showed that the average biofilm thickness on the membrane decreased after elevating the permeate flux from 20 to 60 L m−2 h−1 while the biofilm thickness increased again after restoring the original flux of 20 L m−2 h−1, indicating the occurrence of biofilm compaction and relaxation. Within a few seconds after the flux change, the biofilm thickness was changed and stabilized, biofilm compaction occurred faster than the relaxation after restoring the original permeate flux. The initial biofilm parameters were not fully reinstated: the biofilm thickness was reduced by 21%, biofilm stiffness had increased and the hydraulic biofilm resistance was elevated by 16%. Biofilm thickness was related to the hydraulic biofilm resistance. Membrane performance losses are related to the biofilm thickness, density and morphology, which are influenced by (variations in) hydraulic conditions. A (temporarily) permeate flux increase caused biofilm compaction, together with membrane performance losses. The impact of biofilms on membrane performance can be influenced (increased and reduced) by operational parameters. The article shows that a (temporary) pressure increase leads to more


    Directory of Open Access Journals (Sweden)

    Li Y.


    Full Text Available Mullite-silica rich glass (MSRG composite is a material which is more efficient than chamotte for refractory utilization of clay. The effects of lightweight MSRG composite aggregate on the properties of refractory castables were studied by XRD, SEM and EDS, etc. Comparing with a common lightweight chamotte aggregate, it was found that the hot modulus of rupture, refractoriness under load and thermal shock resistance of the castable with lightweight MSRG aggregate were higher than those of the castable with a common lightweight chamotte aggregate because MSRG did not contain silica crystalline phases and contained a liquid phase with very high viscosity at high temperature. The castables with lightweight chamotte aggregate have higher thermal expansion because of existence of cristobalite and quartz, and have lower thermal conductivity because of higher porosity.

  16. Properties of Structural Lightweight Concrete Filled with Palm-Based Polyurethane

    Directory of Open Access Journals (Sweden)

    Kamarul Aini Mohd Sari


    Full Text Available Four experiments were conducted to characterize the properties of palm-based polyurethane (PU foam in lightweight concrete. The PU foam was synthesized from palm kernel oil-based polyol reacted with 2, 4-methylene diphenyl diisocyanate. Polyurethane as lightweight aggregate was mixed with ordinary cement, sand, and water to form lightweight concrete. The microstructure of PU aggregate can be accessed from optical micrographs. Density, compressive strength, distribution of fine aggregate, and the interfacial zone were also investigated. The result showed that palm-based lightweight concrete has excellent compressive strength (17.5 MPa, and fulfilled the minimum strength requirement for structural concrete. Palm-based lightweight concrete with 0.6 w/c ratio and 3% w/w PU system achieved 1770 kg/m3 presented uniform dispersion of aggregate and excellent mechanical bonding.

  17. High Impact Technology Compact Combustion (HITCC) Compact Core Technologies (United States)


    correlation as the chemical “timescale.” The resulting correlation equation is Eq 22. Including laminar flame speed improved the R-squared value from...including: 1) ultra-compact combustors, 2) inter-turbine burner concepts, 3) bluff-body stabilized turbulent flames, 4) well-stirred reactors for... chemical kinetics, and 5) detonation-stabilized turbulent flames. Lean blowout data was collected on propane and jet fuel bluff-body stabilized flames

  18. Mechanical properties of self-compacting concrete state-of-the-art report of the RILEM technical committee 228-MPS on mechanical properties of self-compacting concrete

    CERN Document Server

    Schutter, Geert


    The State-of-the-Art Report of RILEM Technical Committee 228-MPS on Mechanical properties of Self-Compacting Concrete (SCC) summarizes an extensive body of information related to mechanical properties and mechanical behaviour of SCC. Due attention is given to the fact that the composition of SCC varies significantly. A wide range of  mechanical properties are considered, including compressive strength, stress-strain relationship, tensile and flexural strengths, modulus of elasticity, shear strength, effect of elevated temperature, such as fire spalling and residual properties after fire, in-situ properties, creep, shrinkage, bond properties, and structural behaviour. A chapter on fibre-reinforced SCC is included, as well as a chapter on specialty SCC, such as light-weight SCC, heavy-weight SCC, preplaced aggregate SCC, special fibre reinforced SCC, and underwater concrete.

  19. 75 FR 41439 - Lightweight Thermal Paper from Germany: Extension of Time Limits for the Preliminary Results of... (United States)


    ... International Trade Administration Lightweight Thermal Paper from Germany: Extension of Time Limits for the... antidumping duty order on lightweight thermal paper from Germany (LTWP), covering the period November 20, 2008... cost of production. See Lightweight Thermal Paper from Germany: Notice of Preliminary Determination...

  20. 76 FR 22078 - Lightweight Thermal Paper From Germany: Notice of Final Results of the First Antidumping Duty... (United States)


    ... International Trade Administration Lightweight Thermal Paper From Germany: Notice of Final Results of the First... administrative review for the antidumping duty order on lightweight thermal paper from Germany.\\2\\ The review... October 31, 2009. \\1\\ See Lightweight Thermal Paper from Germany: Notice of Partial Rescission...

  1. Bed form dynamics in distorted lightweight scale models (United States)

    Aberle, Jochen; Henning, Martin; Ettmer, Bernd


    The adequate prediction of flow and sediment transport over bed forms presents a major obstacle for the solution of sedimentation problems in alluvial channels because bed forms affect hydraulic resistance, sediment transport, and channel morphodynamics. Moreover, bed forms can affect hydraulic habitat for biota, may introduce severe restrictions to navigation, and present a major problem for engineering structures such as water intakes and groynes. The main body of knowledge on the geometry and dynamics of bed forms such as dunes originates from laboratory and field investigations focusing on bed forms in sand bed rivers. Such investigations enable insight into the physics of the transport processes, but do not allow for the long term simulation of morphodynamic development as required to assess, for example, the effects of climate change on river morphology. On the other hand, this can be achieved through studies with distorted lightweight scale models allowing for the modification of the time scale. However, our understanding of how well bed form geometry and dynamics, and hence sediment transport mechanics, are reproduced in such models is limited. Within this contribution we explore this issue using data from investigations carried out at the Federal Waterways and Research Institute in Karlsruhe, Germany in a distorted lightweight scale model of the river Oder. The model had a vertical scale of 1:40 and a horizontal scale of 1:100, the bed material consisted of polystyrene particles, and the resulting dune geometry and dynamics were measured with a high spatial and temporal resolution using photogrammetric methods. Parameters describing both the directly measured and up-scaled dune geometry were determined using the random field approach. These parameters (e.g., standard deviation, skewness, kurtosis) will be compared to prototype observations as well as to results from the literature. Similarly, parameters describing the lightweight bed form dynamics, which

  2. Lightweight and Statistical Techniques for Petascale PetaScale Debugging

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Barton


    This project investigated novel techniques for debugging scientific applications on petascale architectures. In particular, we developed lightweight tools that narrow the problem space when bugs are encountered. We also developed techniques that either limit the number of tasks and the code regions to which a developer must apply a traditional debugger or that apply statistical techniques to provide direct suggestions of the location and type of error. We extend previous work on the Stack Trace Analysis Tool (STAT), that has already demonstrated scalability to over one hundred thousand MPI tasks. We also extended statistical techniques developed to isolate programming errors in widely used sequential or threaded applications in the Cooperative Bug Isolation (CBI) project to large scale parallel applications. Overall, our research substantially improved productivity on petascale platforms through a tool set for debugging that complements existing commercial tools. Previously, Office Of Science application developers relied either on primitive manual debugging techniques based on printf or they use tools, such as TotalView, that do not scale beyond a few thousand processors. However, bugs often arise at scale and substantial effort and computation cycles are wasted in either reproducing the problem in a smaller run that can be analyzed with the traditional tools or in repeated runs at scale that use the primitive techniques. New techniques that work at scale and automate the process of identifying the root cause of errors were needed. These techniques significantly reduced the time spent debugging petascale applications, thus leading to a greater overall amount of time for application scientists to pursue the scientific objectives for which the systems are purchased. We developed a new paradigm for debugging at scale: techniques that reduced the debugging scenario to a scale suitable for traditional debuggers, e.g., by narrowing the search for the root-cause analysis

  3. Energy reduction through voltage scaling and lightweight checking (United States)

    Kadric, Edin

    As the semiconductor roadmap reaches smaller feature sizes and the end of Dennard Scaling, design goals change, and managing the power envelope often dominates delay minimization. Voltage scaling remains a powerful tool to reduce energy. We find that it results in about 60% geomean energy reduction on top of other common low-energy optimizations with 22nm CMOS technology. However, when voltage is reduced, it becomes easier for noise and particle strikes to upset a node, potentially causing Silent Data Corruption (SDC). The 60% energy reduction, therefore, comes with a significant drop in reliability. Duplication with checking and triple-modular redundancy are traditional approaches used to combat transient errors, but spending 2--3x the energy for redundant computation can diminish or reverse the benefits of voltage scaling. As an alternative, we explore the opportunity to use checking operations that are cheaper than the base computation they are guarding. We devise a classification system for applications and their lightweight checking characteristics. In particular, we identify and evaluate the effectiveness of lightweight checks in a broad set of common tasks in scientific computing and signal processing. We find that the lightweight checks cost only a fraction of the base computation (0-25%) and allow us to recover the reliability losses from voltage scaling. Overall, we show about 50% net energy reduction without compromising reliability compared to operation at the nominal voltage. We use FPGAs (Field-Programmable Gate Arrays) in our work, although the same ideas can be applied to different systems. On top of voltage scaling, we explore other common low-energy techniques for FPGAs: transmission gates, gate boosting, power gating, low-leakage (high-Vth) processes, and dual-V dd architectures. We do not scale voltage for memories, so lower voltages help us reduce logic and interconnect energy, but not memory energy. At lower voltages, memories become dominant

  4. Warm compaction powder metallurgy of Cu

    Institute of Scientific and Technical Information of China (English)

    NGAI Tungwai Leo; WANG Shang-lin; LI Yuan-yuan; ZHOU Zho-yao; CHEN Wei-ping


    A series of experiments were carried out using different admixed lubricant contents,different compaction pressures and temperatures in order to study the warm compaction of copper powder.Results show that too much admixed lubricant will lead to the squeeze out of the lubricant from the compact during the warm compaction processing of Cu powder.Results also show that blisters can be found in sintered samples that contain lubricant less than 0.15% (mass fraction).Optimal warm compaction parameters for producing high density powder metallurgy copper material are obtained.Compacts with green density of 8.6 g/cm3 and a sintered density of 8.83 g/cm3 can be produced by warm compacting the Cu powder,which contains 0.2% admixed lubricant,and is compacted at 145 ℃ with a pressure of 700 Mpa.

  5. Equationally Compact Acts : Coproducts / Peeter Normak

    Index Scriptorium Estoniae

    Normak, Peeter


    In this article equational compactness of acts and its generalizations are discussed. As equational compactness does not carry over to coproducts a slight generalization of c-equational campactness is introduced. It is proved that a coproduct of acts is c-equationally compact if and only if all components are c-equationally campact

  6. The Kolmogorov-Riesz compactness theorem

    CERN Document Server

    Hanche-Olsen, Harald


    We show that the Arzela-Ascoli theorem and Kolmogorov compactness theorem both are consequences of a simple lemma on compactness in metric spaces. Their relation to Helly's theorem is discussed. The paper contains a detailed discussion on the historical background of the Kolmogorov compactness theorem.

  7. Formation and evolution of compact binaries

    NARCIS (Netherlands)

    Sluijs, Marcel Vincent van der


    In this thesis we investigate the formation and evolution of compact binaries. Chapters 2 through 4 deal with the formation of luminous, ultra-compact X-ray binaries in globular clusters. We show that the proposed scenario of magnetic capture produces too few ultra-compact X-ray binaries to explain

  8. A Lightweight Distributed Solution to Content Replication in Mobile Networks

    CERN Document Server

    La, Chi-Anh; Casetti, Claudio; Chiasserini, Carla-Fabiana; Fiore, Marco


    Performance and reliability of content access in mobile networks is conditioned by the number and location of content replicas deployed at the network nodes. Facility location theory has been the traditional, centralized approach to study content replication: computing the number and placement of replicas in a network can be cast as an uncapacitated facility location problem. The endeavour of this work is to design a distributed, lightweight solution to the above joint optimization problem, while taking into account the network dynamics. In particular, we devise a mechanism that lets nodes share the burden of storing and providing content, so as to achieve load balancing, and decide whether to replicate or drop the information so as to adapt to a dynamic content demand and time-varying topology. We evaluate our mechanism through simulation, by exploring a wide range of settings and studying realistic content access mechanisms that go beyond the traditional assumptionmatching demand points to their closest con...

  9. An Ultra-Lightweight Encryption Scheme in Underwater Acoustic Networks

    Directory of Open Access Journals (Sweden)

    Chunyan Peng


    Full Text Available We tackle a fundamental security problem in underwater acoustic networks (UANs. The S-box in the existing block encryption algorithm is more energy consuming and unsuitable for resources-constrained UANs. In this paper, instead of S-box, we present a lightweight, 8-round iteration block cipher algorithm for UANs communication based on chaotic theory and increase the key space by changing the number of iteration round. We further propose secure network architecture of UANs. By analysis, our algorithm can resist brute-force searches and adversarial attacks. Simulation results show that, compared with traditional AES-128 and PRESENT algorithms, our cryptographic algorithm can make a good trade-off between security and overhead, has better energy efficiency, and applies to UANs.

  10. Vibration Transmission in a Multi-Storey Lightweight Building

    DEFF Research Database (Denmark)

    Niu, Bin; Andersen, Lars Vabbersgaard; Kiel, Nikolaj


    This paper develops a parametric modelling and analysis approach to investigate the vibration transmission in lightweight buildings. The main focus of the research is to investigate the influence of geometry and configuration of the building on the vibration transmission. A building with a single...... to investigate the transmission of vibration. The influence of different excitation frequencies on the vibration transmission is studied and discussed. The vibration response in two different receiving rooms, one near the source and one far from the source, is illustrated and discussed for the various geometric...... in vibration transmission in a building. The influence on the flanking transmission of introducing a neighbouring room in the direction along the building or on top of the building is discussed. •The vibration transmission in buildings with different room sizes is analyzed and discussed. Based on the parameter...

  11. Thermal conductivity of newspaper sandwiched aerated lightweight concrete panel

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Soon-Ching; Low, Kaw-Sai [Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Genting Kelang, Setapak, 53300 Kuala Lumpur, Wilayah Persekutuan (Malaysia)


    Investigation on the thermal conductivity of newspaper sandwiched aerated lightweight concrete (ALC) panels is the main purpose of this study. Various densities of ALC panels ranging from 1700, 1400 and 1100 kg/m{sup 3} with three different aerial intensities of newspaper sandwiched were produced. Investigation was limited to the effect of aerial intensity of newspaper sandwiched and the effect of density of ALC on thermal conductivity. It is found that the thermal conductivity of newspaper sandwiched ALC panels reduced remarkably compared to control ALC panels. The reduction was recorded at 18.0%, 21.8% and 20.7% correspond to densities of 1700, 1400 and 1100 kg/m{sup 3} with just a mere 0.05 g/cm{sup 2} aerial intensity of newspaper sandwiched. Newspaper sandwiched has a significant impact on the performance of thermal conductivity of ALC panels based on regression analysis. (author)

  12. Research on the Mo del of a Lightweight Resource Addressing

    Institute of Scientific and Technical Information of China (English)

    LUO Bingqing; SUN Zhixin


    This paper discussed the characteristics of addressing from the perspective of Internet address-ing mechanism. An Internet of things (IOT) resource ad-dressing iteration model was defined. In the model, a di-rect addressing mode for active nodes and an indirect addressing mode for passive codes were proposed, which meet the requirement for multiple encoding mode. A uni-fied IOT resource lightweight addressing scheme based on IPv6 has been proposed to implement the two addressing modes. The scheme utilized the virtual domain to solve the problem of the heterogeneous encoding. The paper imple-mented the addressing process from the Internet host to the sensor node based on IPv6 over low-power wireless personal area networks (6LoWPAN) protocol. The experi-ment results show that the scheme is performed to realize communication between wireless sensor networks and IPv6 networks.

  13. Lightweight Interactions for Reciprocal Cooperation in a Social Network Game

    CERN Document Server

    Takano, Masanori; Fukuda, Ichiro


    The construction of reciprocal relationships requires cooperative interactions during the initial meetings. However, cooperative behavior with strangers is risky because the strangers may be exploiters. In this study, we show that people increase the likelihood of cooperativeness of strangers by using lightweight non-risky interactions in risky situations based on the analysis of a social network game (SNG). They can construct reciprocal relationships in this manner. The interactions involve low-cost signaling because they are not generated at any cost to the senders and recipients. Theoretical studies show that low-cost signals are not guaranteed to be reliable because the low-cost signals from senders can lie at any time. However, people used low-cost signals to construct reciprocal relationships in an SNG, which suggests the existence of mechanisms for generating reliable, low-cost signals in human evolution.

  14. AEGIS: A Lightweight Firewall for Wireless Sensor Networks (United States)

    Hossain, Mohammad Sajjad; Raghunathan, Vijay

    Firewalls are an essential component in today's networked computing systems (desktops, laptops, and servers) and provide effective protection against a variety of over-the-network security attacks. With the development of technologies such as IPv6 and 6LoWPAN that pave the way for Internet-connected embedded systems and sensor networks, these devices will soon be subject to (and need to be defended against) similar security threats. As a first step, this paper presents Aegis, a lightweight, rule-based firewall for networked embedded systems such as wireless sensor networks. Aegis is based on a semantically rich, yet simple, rule definition language. In addition, Aegis is highly efficient during operation, runs in a transparent manner from running applications, and is easy to maintain. Experimental results obtained using real sensor nodes and cycle-accurate simulations demonstrate that Aegis successfully performs gatekeeping of a sensor node's communication traffic in a flexible manner with minimal overheads.

  15. Lightweight performance data collectors 2.0 with Eiger support.

    Energy Technology Data Exchange (ETDEWEB)

    Allan, Benjamin A.


    We report on the use and design of a portable, extensible performance data collection tool motivated by modeling needs of the high performance computing systems co-design com- munity. The lightweight performance data collectors with Eiger support is intended to be a tailorable tool, not a shrink-wrapped library product, as pro ling needs vary widely. A single code markup scheme is reported which, based on compilation ags, can send perfor- mance data from parallel applications to CSV les, to an Eiger mysql database, or (in a non-database environment) to at les for later merging and loading on a host with mysql available. The tool supports C, C++, and Fortran applications.


    Directory of Open Access Journals (Sweden)

    Oreshkin Dmitriy Vladimirovich


    The paper also presents the results of the research of the microstructure of spilt Portland cement and hollow glass spheres, their mineral and chemical analyses, as well as the properties of masonry mortars. The paper presents a conclusion that their high process-dependent parameters and superior operating performance are attainable through the introduction of effective hollow glass spheres into masonry mortars and the application of the extrusion method. The aforementioned novelties may reduce the water consumption rate, improve the strength, freeze resistance and durability of cement mortars. The preparation of this paper involved the study of nine reference books. This paper is the first one of a series of papers covering the method of extrusion of lightweight cement mortars.

  17. Lightweight Phishing URLs Detection Using N-gram Features

    Directory of Open Access Journals (Sweden)

    Ammar Yahya Daeef


    Full Text Available Phishing is a kind of attack that belongs to social engineering and this attack seeks to trick people in order to let them reveal their confidential information. Several methods are introduced to detect phishing websites by using different types of features. Unfortunately, these techniques implemented for specific attack vector such as detecting phishing emails which make implementing wide scope detection system crucial demand. URLs analysis proved to be a strong method to detect malicious attacks by previous researches. This technique uses various URL features such as host information, lexical, and other type of features. In this paper, we present wide scope and lightweight phishing detection system using lexical features only. The proposed classifier provides accuracy of 93% with 0.12 second processing time per URL.

  18. Robustness of Modal Parameter Estimation Methods Applied to Lightweight Structures

    DEFF Research Database (Denmark)

    Dickow, Kristoffer Ahrens; Kirkegaard, Poul Henning; Andersen, Lars Vabbersgaard


    of nominally identical test subjects. However, the literature on modal testing of timber structures is rather limited and the applicability and robustness of dierent curve tting methods for modal analysis of such structures is not described in detail. The aim of this paper is to investigate the robustness....... The ability to handle closely spaced modes and broad frequency ranges is investigated for a numerical model of a lightweight junction under dierent signal-to-noise ratios. The selection of both excitation points and response points are discussed. It is found that both the Rational Fraction Polynomial-Z method...... of two parameter estimation methods built into the commercial modal testing software B&K Pulse Re ex Advanced Modal Analysis. The investigations are done by means of frequency response functions generated from a nite-element model and subjected to articial noise before being analyzed with Pulse Re ex...

  19. Lightweight high temperature test furnace. 21st century technology

    Energy Technology Data Exchange (ETDEWEB)

    De Groot, F.C.


    A new high-temperature lightweight furnace design offers potential energy savings, thus reducing emissions and costs, and improves product quality. The Gasunie Research 12 m3 test furnace results are: 36% less heat needed to heat up the furnace; first tests show that 18% of flue gas heat loss is saved through pulse/pause firing; reduced carbon dioxide and gaseous hydrogen fluorides (HF) emissions; improved temperature homogeneity in product batch enables higher throughput; new dust-free combination of Refractory Ceramic Fibres (RCFs) have been tested successfully up to 1250C; new high-temperature vitreous wool (RCFs) with high solubility in body fluids and hence no hazard classification has been successfully tested; furnace control system developed and tested with good results, based on a standard industrial PLC, within stringent gas safety requirements.

  20. LPKI - A Lightweight Public Key Infrastructure for the Mobile Environments

    CERN Document Server

    Toorani, Mohsen; 10.1109/ICCS.2008.4737164


    The non-repudiation as an essential requirement of many applications can be provided by the asymmetric key model. With the evolution of new applications such as mobile commerce, it is essential to provide secure and efficient solutions for the mobile environments. The traditional public key cryptography involves huge computational costs and is not so suitable for the resource-constrained platforms. The elliptic curve-based approaches as the newer solutions require certain considerations that are not taken into account in the traditional public key infrastructures. The main contribution of this paper is to introduce a Lightweight Public Key Infrastructure (LPKI) for the constrained platforms such as mobile phones. It takes advantages of elliptic curve cryptography and signcryption to decrease the computational costs and communication overheads, and adapting to the constraints. All the computational costs of required validations can be eliminated from end-entities by introduction of a validation authority to th...

  1. Lightweight Mutual Authentication Protocol for Low Cost RFID Tags

    CERN Document Server

    Ahmed, Eslam Gamal; Hashem, Mohamed; 10.5121/ijnsa.2010.2203


    Radio Frequency Identification (RFID) technology one of the most promising technologies in the field of ubiquitous computing. Indeed, RFID technology may well replace barcode technology. Although it offers many advantages over other identification systems, there are also associated security risks that are not easy to be addressed. When designing a real lightweight authentication protocol for low cost RFID tags, a number of challenges arise due to the extremely limited computational, storage and communication abilities of Low-cost RFID tags. This paper proposes a real mutual authentication protocol for low cost RFID tags. The proposed protocol prevents passive attacks as active attacks are discounted when designing a protocol to meet the requirements of low cost RFID tags. However the implementation of the protocol meets the limited abilities of low cost RFID tags.

  2. Lightweight Distance bound Protocol for Low Cost RFID Tags

    CERN Document Server

    Ahmed, Eslam Gamal; Hashem, Mohamed


    Almost all existing RFID authentication schemes (tag/reader) are vulnerable to relay attacks, because of their inability to estimate the distance to the tag. These attacks are very serious since it can be mounted without the notice of neither the reader nor the tag and cannot be prevented by cryptographic protocols that operate at the application layer. Distance bounding protocols represent a promising way to thwart relay attacks, by measuring the round trip time of short authenticated messages. All the existing distance bounding protocols use random number generator and hash functions at the tag side which make them inapplicable at low cost RFID tags. This paper proposes a lightweight distance bound protocol for low cost RFID tags. The proposed protocol based on modified version of Gossamer mutual authentication protocol. The implementation of the proposed protocol meets the limited abilities of low-cost RFID tags.

  3. Optical Fibres Contactless Sensor for Dynamic Testing of Lightweight Structures

    Directory of Open Access Journals (Sweden)

    L. Bregant


    Full Text Available With dynamic testing, engineers describe activities focused on the identification of some properties of vibrating structures. This step requires for the measurements of excitations and responses signals, applying appropriate sensors directly on the test article. These instruments modify the system's mass and stiffness distributions and eventually the eigen-properties of the structure. These errors become unacceptable especially when testing lightweight structures. This paper shows the results of some tests performed on a small compressor with the purpose of identifying the blades’ natural frequencies and modes. It compares the acquisitions performed with standard accelerometers and two different contact-less systems using as exciters either a micro-hammer or a micro inertial shaker. The paper shows how the contact-less sensors provide good quality data and consistent results in the mode identification phase.

  4. Image Encryption Using a Lightweight Stream Encryption Algorithm

    Directory of Open Access Journals (Sweden)

    Saeed Bahrami


    Full Text Available Security of the multimedia data including image and video is one of the basic requirements for the telecommunications and computer networks. In this paper, we consider a simple and lightweight stream encryption algorithm for image encryption, and a series of tests are performed to confirm suitability of the described encryption algorithm. These tests include visual test, histogram analysis, information entropy, encryption quality, correlation analysis, differential analysis, and performance analysis. Based on this analysis, it can be concluded that the present algorithm in comparison to A5/1 and W7 stream ciphers has the same security level, is better in terms of the speed of performance, and is used for real-time applications.

  5. Modification of Lightweight Aggregates’ Microstructure by Used Motor Oil Addition

    Directory of Open Access Journals (Sweden)

    Małgorzata Franus


    Full Text Available An admixture of lightweight aggregate substrates (beidellitic clay containing 10 wt % of natural clinoptilolite or Na-P1 zeolite with used motor oil (1 wt %–8 wt % caused marked changes in the aggregates’ microstructure, measured by a combination of mercury porosimetry (MIP, microtomography (MT, and scanning electron microscopy. Maximum porosity was produced at low (1%–2% oil concentrations and it dropped at higher concentrations, opposite to the aggregates’ bulk density. Average pore radii, measured by MIP, decreased with an increasing oil concentration, whereas larger (MT pore sizes tended to increase. Fractal dimension, derived from MIP data, changed similarly to the MIP pore radius, while that derived from MT remained unaltered. Solid phase density, measured by helium pycnometry, initially dropped slightly and then increased with the amount of oil added, which was most probably connected to changes in the formation of extremely small closed pores that were not available for He atoms.

  6. Lightweight Mechanical Metamaterials with Tunable Negative Thermal Expansion. (United States)

    Wang, Qiming; Jackson, Julie A; Ge, Qi; Hopkins, Jonathan B; Spadaccini, Christopher M; Fang, Nicholas X


    Ice floating on water is a great manifestation of negative thermal expansion (NTE) in nature. The limited examples of natural materials possessing NTE have stimulated research on engineered structures. Previous studies on NTE structures were mostly focused on theoretical design with limited experimental demonstration in two-dimensional planar geometries. In this work, aided with multimaterial projection microstereolithography, we experimentally fabricate lightweight multimaterial lattices that exhibit significant negative thermal expansion in three directions and over a temperature range of 170 degrees. Such NTE is induced by the structural interaction of material components with distinct thermal expansion coefficients. The NTE can be tuned over a large range by varying the thermal expansion coefficient difference between constituent beams and geometrical arrangements. Our experimental results match qualitatively with a simple scaling law and quantitatively with computational models.

  7. A Light-Weight Communication Library for Distributed Computing

    CERN Document Server

    Groen, Derek; Grosso, Paola; de Laat, Cees; Zwart, Simon Portegies; 10.1088/1749-4699/3/1/015002


    We present MPWide, a platform independent communication library for performing message passing between computers. Our library allows coupling of several local MPI applications through a long distance network and is specifically optimized for such communications. The implementation is deliberately kept light-weight, platform independent and the library can be installed and used without administrative privileges. The only requirements are a C++ compiler and at least one open port to a wide area network on each site. In this paper we present the library, describe the user interface, present performance tests and apply MPWide in a large scale cosmological N-body simulation on a network of two computers, one in Amsterdam and the other in Tokyo.

  8. Alumina lightweight ceramics modified with plasma synthesized nanopowders (United States)

    Zake, I.; Svinka, R.; Svinka, V.; Palcevskis, E.


    The aim of this study is to clarify possibilities of using plasma synthesized Al2O3 and SiC nanopowders as additives in alumina lightweight ceramics prepared by slip casting. Each plasma synthesized nanopowder (PSNP) was incorporated in the material by a different method, because of their diverse influence on the properties of slip. Al2O3 PSNP was introduced in the matrix in form of aqueous suspension. SiC nanopowder was added directly to raw materials. Bending strength, bulk density, apparent porosity and thermal shock resistance were determined to evaluate the influence of these additives. The effect of Al2O3 PSNP addition on the properties of material depends on the initial sintering temperature. SiC particles during sintering oxidize into SiO2 and then in the reaction with alumina form mullite. Addition of SiC considerably improves bending strength and thermal shock resistance.

  9. The 3D lightweight structural characteristics of the beetle forewing. (United States)

    Chen, Jinxiang; Tuo, Wanyong; Guo, Zhensheng; Yan, Lili


    The present paper renewedly expounds upon the characteristics of the 3D lightweight structure of beetle forewings and notes that two biomimetic structures (models) that have appeared in recent years do not comply with these characteristics based on a comparison of the structures of the biological prototypes. The first model features transverse tubules based on observations of circular holes in cross-sectional figures of the Cybister forewing. The second is a biomimetic spherical cavity model with hollow trabeculae that reportedly exhibits superior mechanical properties because its structures are most similar to the biological prototype. Finally, a false biomimetic proposition that the mechanical properties of biomimetic structures with "fiber winding" patterns are superior to those of structures constructed of pure "epoxy" is also noted. Hopefully, the present study can serve to improve the state of research on biomimetic applications of beetle forewing structures.

  10. Lightweight Mechanical Metamaterials with Tunable Negative Thermal Expansion (United States)

    Wang, Qiming; Jackson, Julie A.; Ge, Qi; Hopkins, Jonathan B.; Spadaccini, Christopher M.; Fang, Nicholas X.


    Ice floating on water is a great manifestation of negative thermal expansion (NTE) in nature. The limited examples of natural materials possessing NTE have stimulated research on engineered structures. Previous studies on NTE structures were mostly focused on theoretical design with limited experimental demonstration in two-dimensional planar geometries. In this work, aided with multimaterial projection microstereolithography, we experimentally fabricate lightweight multimaterial lattices that exhibit significant negative thermal expansion in three directions and over a temperature range of 170 degrees. Such NTE is induced by the structural interaction of material components with distinct thermal expansion coefficients. The NTE can be tuned over a large range by varying the thermal expansion coefficient difference between constituent beams and geometrical arrangements. Our experimental results match qualitatively with a simple scaling law and quantitatively with computational models.

  11. A Lightweight Approach to Performance Portability with targetDP

    CERN Document Server

    Gray, Alan


    Leading HPC systems achieve their status through use of highly parallel devices such as NVIDIA GPUs or Intel Xeon Phi many-core CPUs. The concept of performance portability across such architectures, as well as traditional CPUs, is vital for the application programmer. In this paper we describe targetDP, a lightweight abstraction layer which allows grid-based applications to target data parallel hardware in a platform agnostic manner. We demonstrate the effectiveness of our pragmatic approach by presenting performance results for a complex fluid application (with which the model was co-designed), plus a separate lattice QCD particle physics code. For each application, a single source code base is seen to achieve portable performance, as assessed within the context of the Roofline model. TargetDP can be combined with MPI to allow use on systems containing multiple nodes: we demonstrate this through provision of scaling results on traditional and GPU-accelerated large scale supercomputers.

  12. Properties of lightweight cement-based composites containing waste polypropylene (United States)

    Záleská, Martina; Pavlíková, Milena; Pavlík, Zbyšek


    Improvement of buildings thermal stability represents an increasingly important trend of the construction industry. This work aims to study the possible use of two types of waste polypropylene (PP) for the development of lightweight cement-based composites with enhanced thermal insulation function. Crushed PP waste originating from the PP tubes production is used for the partial replacement of silica sand by 10, 20, 30, 40 and 50 mass%, whereas a reference mixture without plastic waste is studied as well. First, basic physical and thermal properties of granular PP random copolymer (PPR) and glass fiber reinforced PP (PPGF) aggregate are studied. For the developed composite mixtures, basic physical, mechanical, heat transport and storage properties are accessed. The obtained results show that the composites with incorporated PP aggregate exhibit an improved thermal insulation properties and acceptable mechanical resistivity. This new composite materials with enhanced thermal insulation function are found to be promising materials for buildings subsoil or floor structures.

  13. Compact differences of composition operators

    CERN Document Server

    Heller, Katherine; Weir, Rachel J


    When $\\varphi$ and $\\psi$ are linear-fractional self-maps of the unit ball $B_N$ in ${\\mathbb C}^N$, $N\\geq 1$, we show that the difference $C_{\\varphi}-C_{\\psi}$ cannot be non-trivially compact on either the Hardy space $H^2(B_N)$ or any weighted Bergman space $A^2_{\\alpha}(B_N)$. Our arguments emphasize geometrical properties of the inducing maps $\\varphi$ and $\\psi$.

  14. Weak compactness of biharmonic maps

    Directory of Open Access Journals (Sweden)

    Shenzhou Zheng


    Full Text Available This article shows that if a sequence of weak solutions of a perturbed biharmonic map satisfies $Phi_ko 0$ in $(W^{2,2}^*$ and $u_kightharpoonup u$ weakly in $W^{2,2}$, then $u$ is a biharmonic map. In particular, we show that the space of biharmonic maps is sequentially compact under the weak-$W^{2,2}$ topology.

  15. Multipole structure of compact objects

    CERN Document Server

    Quevedo, Hernando


    We analyze the applications of general relativity in relativistic astrophysics in order to solve the problem of describing the geometric and physical properties of the interior and exterior gravitational and electromagnetic fields of compact objects. We focus on the interpretation of exact solutions of Einstein's equations in terms of their multipole moments structure. In view of the lack of physical interior solutions, we propose an alternative approach in which higher multipoles should be taken into account.

  16. Target-local Gromov compactness

    CERN Document Server

    Fish, Joel W


    We prove a version of Gromov's compactness theorem for pseudo-holomorphic curves which holds locally in the target symplectic manifold. This result applies to sequences of curves with an unbounded number of free boundary components, and in families of degenerating target manifolds which have unbounded geometry (e.g. no uniform energy threshold). Core elements of the proof regard curves as submanifolds (rather than maps) and then adapt methods from the theory of minimal surfaces.

  17. Lightweight High Efficiency Electric Motors for Space Applications (United States)

    Robertson, Glen A.; Tyler, Tony R.; Piper, P. J.


    Lightweight high efficiency electric motors are needed across a wide range of space applications from - thrust vector actuator control for launch and flight applications to - general vehicle, base camp habitat and experiment control for various mechanisms to - robotics for various stationary and mobile space exploration missions. QM Power?s Parallel Path Magnetic Technology Motors have slowly proven themselves to be a leading motor technology in this area; winning a NASA Phase II for "Lightweight High Efficiency Electric Motors and Actuators for Low Temperature Mobility and Robotics Applications" a US Army Phase II SBIR for "Improved Robot Actuator Motors for Medical Applications", an NSF Phase II SBIR for "Novel Low-Cost Electric Motors for Variable Speed Applications" and a DOE SBIR Phase I for "High Efficiency Commercial Refrigeration Motors" Parallel Path Magnetic Technology obtains the benefits of using permanent magnets while minimizing the historical trade-offs/limitations found in conventional permanent magnet designs. The resulting devices are smaller, lower weight, lower cost and have higher efficiency than competitive permanent magnet and non-permanent magnet designs. QM Power?s motors have been extensively tested and successfully validated by multiple commercial and aerospace customers and partners as Boeing Research and Technology. Prototypes have been made between 0.1 and 10 HP. They are also in the process of scaling motors to over 100kW with their development partners. In this paper, Parallel Path Magnetic Technology Motors will be discussed; specifically addressing their higher efficiency, higher power density, lighter weight, smaller physical size, higher low end torque, wider power zone, cooler temperatures, and greater reliability with lower cost and significant environment benefit for the same peak output power compared to typically motors. A further discussion on the inherent redundancy of these motors for space applications will be provided.

  18. Comminution circuits for compact itabirites

    Directory of Open Access Journals (Sweden)

    Pedro Ferreira Pinto

    Full Text Available Abstract In the beneficiation of compact Itabirites, crushing and grinding account for major operational and capital costs. As such, the study and development of comminution circuits have a fundamental importance for feasibility and optimization of compact Itabirite beneficiation. This work makes a comparison between comminution circuits for compact Itabirites from the Iron Quadrangle. The circuits developed are: a crushing and ball mill circuit (CB, a SAG mill and ball mill circuit (SAB and a single stage SAG mill circuit (SSSAG. For the SAB circuit, the use of pebble crushing is analyzed (SABC. An industrial circuit for 25 million tons of run of mine was developed for each route from tests on a pilot scale (grinding and industrial scale. The energy consumption obtained for grinding in the pilot tests was compared with that reported by Donda and Bond. The SSSAG route had the lowest energy consumption, 11.8kWh/t and the SAB route had the highest energy consumption, 15.8kWh/t. The CB and SABC routes had a similar energy consumption of 14.4 kWh/t and 14.5 kWh/t respectively.

  19. Strings in compact cosmological spaces

    CERN Document Server

    Craps, Ben; Konechny, Anatoly


    We confront the problem of giving a fundamental definition to perturbative string theory in spacetimes with totally compact space (taken to be a torus for simplicity, though the nature of the problem is very general) and non-compact time. Due to backreaction induced by the presence of even a single string quantum, the usual formulation of perturbative string theory in a fixed classical background is infrared-divergent at all subleading orders in the string coupling, and needs to be amended. The problem can be seen as a closed string analogue of D0-brane recoil under an impact by closed strings (a situation displaying extremely similar infrared divergences). Inspired by the collective coordinate treatment of the D0-brane recoil, whereby the translational modes of the D0-brane are introduced as explicit dynamical variables in the path integral, we construct a similar formalism for the case of string-induced gravitational backreaction, in which the spatially uniform modes of the background fields on the compact ...

  20. Compact Stellarator Path to DEMO (United States)

    Lyon, J. F.


    Issues for a DEMO reactor are sustaining an ignited/high-Q plasma in steady state, avoiding disruptions and large variations in power flux to the wall, adequate confinement of thermal plasma and alpha-particles, control of a burning plasma, particle and power handling, etc. Compact stellarators have key advantages -- steady-state high-plasma-density operation without external current drive or disruptions, stability without a close conducting wall or active feedback systems, and low recirculating power -- in addition to moderate plasma aspect ratio, good confinement, and high-beta potential. The ARIES-CS study established that compact stellarators can be competitive with tokamaks as reactors. Many of the issues for a compact stellarator DEMO can be answered using results from large tokamaks, ITER D-T experiments and fusion materials, technology and component development programs, in addition to stellarators in operation, under construction or in development. However, a large next-generation stellarator will be needed to address some physics issues: size scaling and confinement at higher parameters, burning plasma issues, and operation with a strongly radiative divertor. Technology issues include simpler coils, structure, and divertor fabrication, and better cost information.

  1. 78 FR 61384 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact (United States)


    ... Federal Bureau of Investigation Meeting of the Compact Council for the National Crime Prevention and... of this notice is to announce a meeting of the National Crime Prevention and Privacy Compact Council (Council) created by the National Crime Prevention and Privacy Compact Act of 1998 (Compact). Thus far,...

  2. 78 FR 20355 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact (United States)


    ... Federal Bureau of Investigation Meeting of the Compact Council for the National Crime Prevention and... this notice is to announce a meeting of the National Crime Prevention and Privacy Compact Council (Council) created by the National Crime Prevention and Privacy Compact Act of 1998 (Compact). Thus far,...

  3. 77 FR 60475 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact (United States)


    ... Federal Bureau of Investigation Meeting of the Compact Council for the National Crime Prevention and... of this notice is to announce a meeting of the National Crime Prevention and Privacy Compact Council (Council) created by the National Crime Prevention and Privacy Compact Act of 1998 (Compact). Thus far,...

  4. 76 FR 20044 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact (United States)


    ... Federal Bureau of Investigation Meeting of the Compact Council for the National Crime Prevention and... this notice is to announce a meeting of the National Crime Prevention and Privacy Compact Council (Council) created by the National Crime Prevention and Privacy Compact Act of 1998 (Compact). Thus far,...

  5. 75 FR 62568 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact (United States)


    ... Federal Bureau of Investigation Meeting of the Compact Council for the National Crime Prevention and... this notice is to announce a meeting of the National Crime Prevention and Privacy Compact Council (Council) created by the National Crime Prevention and Privacy Compact Act of 1998 (Compact). Thus far,...

  6. 76 FR 66326 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact (United States)


    ... Federal Bureau of Investigation Meeting of the Compact Council for the National Crime Prevention and... this notice is to announce a meeting of the National Crime Prevention and Privacy Compact Council (Council) created by the National Crime Prevention and Privacy Compact Act of 1998 (Compact). Thus far,...

  7. 77 FR 20051 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact (United States)


    ... Federal Bureau of Investigation Meeting of the Compact Council for the National Crime Prevention and... this notice is to announce a meeting of the National Crime Prevention and Privacy Compact Council (Council) created by the National Crime Prevention and Privacy Compact Act of 1998 (Compact). Thus far,...

  8. Conserved role of unc-79 in ethanol responses in lightweight mutant mice.

    Directory of Open Access Journals (Sweden)

    David J Speca


    Full Text Available The mechanisms by which ethanol and inhaled anesthetics influence the nervous system are poorly understood. Here we describe the positional cloning and characterization of a new mouse mutation isolated in an N-ethyl-N-nitrosourea (ENU forward mutagenesis screen for animals with enhanced locomotor activity. This allele, Lightweight (Lwt, disrupts the homolog of the Caenorhabditis elegans (C. elegans unc-79 gene. While Lwt/Lwt homozygotes are perinatal lethal, Lightweight heterozygotes are dramatically hypersensitive to acute ethanol exposure. Experiments in C. elegans demonstrate a conserved hypersensitivity to ethanol in unc-79 mutants and extend this observation to the related unc-80 mutant and nca-1;nca-2 double mutants. Lightweight heterozygotes also exhibit an altered response to the anesthetic isoflurane, reminiscent of unc-79 invertebrate mutant phenotypes. Consistent with our initial mapping results, Lightweight heterozygotes are mildly hyperactive when exposed to a novel environment and are smaller than wild-type animals. In addition, Lightweight heterozygotes exhibit increased food consumption yet have a leaner body composition. Interestingly, Lightweight heterozygotes voluntarily consume more ethanol than wild-type littermates. The acute hypersensitivity to and increased voluntary consumption of ethanol observed in Lightweight heterozygous mice in combination with the observed hypersensitivity to ethanol in C. elegans unc-79, unc-80, and nca-1;nca-2 double mutants suggests a novel conserved pathway that might influence alcohol-related behaviors in humans.

  9. Motion Analysis of Fiber Band in Compact Field of Compact Spinning

    Institute of Scientific and Technical Information of China (English)


    The technological process of compact spinning and the compact procedure of fiber band in compact field are briefly illustrated. The motions of fiber band in compact field are discussed theoretically from which tilting angle of suction slot in profile tube, additional twists created by fiber band's rotating around its own axis and ultimate twists in compact yarn are deduced accordingly. The existence of additional twists is also verified through experiments.

  10. Lightweight design and finite element analysis of primary mirror for the space telescope (United States)

    Zhang, Dandan; Li, Weiyan; Lv, Qunbo; Liu, Yangyang; Chen, Xinwen


    In order to satisfy the strict requirements of the lightweight ratios and high dimensional stability for space mirror, the design method of lightweight structure and the flexible supporting structure of the primary mirror is proposed. Subsequently, the surface deformations of two different lightweight structures for primary mirror are discussed for analyzing the influence of the mirror weight on its surface. Finally, the finite element models for primary mirror assembly are built for calculating the surface deformation caused by different gravity orientations and various thermal environments. It is proved that the weight, stiffness and surface accuracy of the structure design for primary mirror can meet the engineering requirement.


    Directory of Open Access Journals (Sweden)



    Full Text Available An m-file for mix design of structural lightweight concrete is presented. Mix design of structural lightweight concrete is conducted using guide in the standards. This may be tasking involving reading and understanding of the relevant standards. This renders the process inefficient and liable to errors in computations. A computer approach to mix design will alleviate this problem. An m-file was developed in MATLAB environment for the concrete mix design. The m-file has been tested and has proved to be efficient in computing the mix composition for the first trial batch of lightweight concrete mixes. It can also perform concrete mixture proportioning adjustment.

  12. A Specialized Lightweight Metamorphic Function for KASUMI Metamorphic Cipher and Its FPGA Implementation

    Directory of Open Access Journals (Sweden)

    Rabie A. Mahmoud


    Full Text Available To enhance the performance of the KASUMI Metamorphic Cipher, we apply a lightweight Metamorphic Structure. The proposed structure uses four lightweight bit-balanced operations in the function Meta-FO of the KASUMI Metamorphic Cipher. These operations are: XOR, INV, XNOR, and NOP for bitwise XOR, invert, XNOR, and no operation respectively building blocks of the Specialized Crypto Logic Unit (SCLU. In this work, we present a lightweight KASUMI Specialized-Metamorphic Cipher. In addition, we provide a Field Programmable Gate Array (FPGA implementation of the proposed algorithm modification.

  13. Project CONDOR: Middle atmosphere wind structure obtained with lightweight inflatable spheres near the equatorial electrojet (United States)

    Schmidlin, F. J.


    Observed correlations between the atmospheric electric field and the neutral wind were studied using additional atmospheric measurements during Project CONDOR. Project CONDOR obtained measurements near the equatorial electrojet (12 S) during March 1983. Neutral atmosphere wind measurements were obtained using lightweight inflatable spheres and temperatures were obtained using a datasonde. The lightweight sphere technology, the wind structure, and temperature structure are described. Results show that the lightweight sphere gives higher vertical resolution of winds below 75 km compared with the standard sphere, but gives little or no improvement above 80 km, and no usable temperature and density data.

  14. Der Global Compact und der Schutz der Menschenrechte


    Hamm, Brigitte I.


    Inhalt: - I. Einleitung - II. Was ist der Global Compact? - III. Wie funktioniert der Global Compact? - IV. Der Global Compact will kein Verhaltenskodex sein. - V. Der Global Compact als Bestandteil von „global governance“ - VI. Der Global Compact und der Schutz der Menschenrechte - VII. Ausschau - Literatur - Teilnehmer des Global Compact

  15. Miniature lightweight x-ray optics (MiXO) for surface elemental composition mapping of asteroids and comets

    CERN Document Server

    Hong, Jaesub


    The compositions of diverse planetary bodies are of fundamental interest to planetary science, providing clues to the formation and evolutionary history of the target bodies and the Solar system as a whole. Utilizing the X-ray fluorescence unique to each atomic element, X-ray imaging spectroscopy is a powerful diagnostic tool of the chemical and mineralogical compositions of diverse planetary bodies. Until now the mass and volume of focusing X-ray optics have been too large for resource-limited in-situ missions, so near-target X-ray observations of planetary bodies have been limited to simple collimator-type X-ray instruments. We introduce a new Miniature lightweight Wolter-I focusing X-ray Optics (MiXO) using metal-ceramic hybrid X-ray mirrors based on electroformed nickel replication and plasma thermal spray processes. MiXO can enable compact, powerful imaging X-ray telescopes suitable for future planetary missions. We illustrate the need for focusing X-ray optics in observing relatively small planetary bod...

  16. Porewater chemistry in compacted bentonite

    Energy Technology Data Exchange (ETDEWEB)

    Muurinen, A.; Lehikoinen, J. [VTT Chemical Technology, Espoo (Finland)


    In this study, the porewater chemistry in compacted bentonite, considered as an engineered barrier in the repository of spent fuel, has been studied in interaction experiments. Many parameters, like the composition and density of bentonite, composition of the solution, bentonite-to-water ratio (B/W), surrounding conditions and experimental time have been varied in the experiments. At the end of the interaction the equilibrating solution, the porewaters squeezed out of the bentonite samples, and bentonites themselves were analyzed to give information for the interpretation and modelling of the interaction. Equilibrium modelling was performed with the HYDRAQL/CE computer code 33 refs.

  17. Compact Hermitian Young Projection Operators

    CERN Document Server

    Alcock-Zeilinger, Judith


    In this paper, we describe a compact and practical algorithm to construct Hermitian Young projection operators for irreducible representations of the special unitary group SU(N), and discuss why ordinary Young projection operators are unsuitable for physics applications. The proof of this construction algorithm uses the iterative method described by Keppeler and Sj\\"odahl. We further show that Hermitian Young projection operators share desirable properties with Young tableaux, namely a nested hierarchy when "adding a particle". We end by exhibiting the enormous advantage of the Hermitian Young projection operators constructed in this paper over those given by Keppeler and Sj\\"odahl.

  18. Compact objects in Horndeski gravity

    CERN Document Server

    Silva, Hector O; Minamitsuji, Masato; Berti, Emanuele


    Horndeski gravity holds a special position as the most general extension of Einstein's theory of general relativity with a single scalar degree of freedom and second-order field equations. Because of these features, Horndeski gravity is an attractive phenomenological playground to investigate the consequences of modifications of general relativity in cosmology and astrophysics. We present a review of the progress made so far in the study of compact objects (black holes and neutron stars) within Horndeski gravity. In particular, we review our recent work on slowly rotating black holes and present some new results on slowly rotating neutron stars.

  19. Self-compacting concrete (SCC)

    DEFF Research Database (Denmark)

    Geiker, Mette Rica


    In many aspects Self-Compacting Concrete (SCC, “Self-Consolidating Concrete” in North America) can be considered the concrete of the future. SCC is a family of tailored concretes with special engineered properties in the fresh state. SCC flows into the formwork and around even complicated...... reinforcement arrangements under its own weight. Thus, SCC is not vibrated like conventional concrete. This drastically improves the working environment during construction, the productivity, and potentially improves the homogeneity and quality of the concrete. In addition SCC provides larger architectural...

  20. Next Generation , Lightweight, Durable Boot Materials to Provide Active & Passive Thermal Protection Project (United States)

    National Aeronautics and Space Administration — The objective of this NASA Phase I SBIR program is to leverage lightweight, durable materials developed by NanoSonic for use within extra vehicular activity (EVA)...

  1. Flexible, Lightweight, Low-Cost Organic Photovoltaics with Improved Efficiency Project (United States)

    National Aeronautics and Space Administration — Both manned and unmanned off-Earth missions of the future will require very lightweight, high efficiency, flexible and durable photovoltaic (PV) arrays to generate...

  2. Ultra-Lightweight, High Efficiency Silicon-Carbide (SIC) Based Power Electronic Converters Project (United States)

    National Aeronautics and Space Administration — This Small Business of Innovation Research Phase I proposal seeks to investigate and prove the feasibility of developing highly efficient, ultra-lightweight SiC...

  3. Lightweight Hybrid Ablator Incorporating Aerogel-Filled Open-Cell Foam Structural Insulator, Phase II Project (United States)

    National Aeronautics and Space Administration — In previous work for NASA and DoD, Ultramet developed lightweight open-cell foam insulators composed of a carbon or ceramic structural foam skeleton filled with a...

  4. Lightweight Hybrid Ablator Incorporating Aerogel-Filled Open-Cell Foam Structural Insulator Project (United States)

    National Aeronautics and Space Administration — In previous work for NASA and DoD, Ultramet developed lightweight open-cell foam insulators composed of a carbon or ceramic structural foam skeleton filled with a...

  5. Flexible, Lightweight, Low-Cost Organic Photovoltaics with Improved Efficiency Project (United States)

    National Aeronautics and Space Administration — Both manned and unmanned off-Earth missions of the future will require very lightweight, inexpensive, high efficiency, flexible and single-use photovoltaic (PV)...

  6. Actively Cooled Silicon Lightweight Mirrors for Far Infrared and Submillimeter Optical Systems Project (United States)

    National Aeronautics and Space Administration — Schafer proposes to demonstrate 2 different methods for actively cooling our 5-7.5 kg/m2 areal density Silicon Lightweight Mirrors (SLMS?) technology for future NASA...

  7. Ultra-Lightweight, High Efficiency Silicon-Carbide (SIC) Based Power Electronic Converters Project (United States)

    National Aeronautics and Space Administration — In Phase I of this project, APEI, Inc. proved the feasibility of creating ultra-lightweight power converters (utilizing now emerging silicon carbide [SiC] power...

  8. Innovative, Lightweight Thoraeus RubberTM for MMOD and Space Radiation Shielding Project (United States)

    National Aeronautics and Space Administration — NanoSonic offers an innovative manufacturing process to yield ultra-lightweight radiation shielding nanocomposites by exploiting the concept of the Thoraeus filter...

  9. Mitigation of Flanking Noise Transmission in Periodic Structures of Lightweight Elements

    DEFF Research Database (Denmark)

    Domadiya, Parthkumar Gandalal

    Lightweight structures becoming increasingly popular within the building industry and hence they requires immediate attention to address their vibro-acoustic behaviour. Flanking noise transmission is one of the main concerns while using lightweight panels in buildings, since sound can travel...... characteristics in periodic structures, the structure must be simplified; hence, one dimensional structures such as bars and beams are considered for further investigation. A periodic bar model comprised of systemically placed Plexiglas and steel elements is generated using two methods: an FE method and a Floquet...... transmission in periodic structures of lightweight elements by employing various numerical, analytical and experimental methods. At first, three dimensional finite-element (FE) models of a Z-shaped lightweight panel structure based on various frame designs, inclusion of air and structural coupling between...

  10. Lightweight Ultrahigh Temperature CMC-Encased C/C Structure for Reentry and Hypersonic Applications Project (United States)

    National Aeronautics and Space Administration — The reentry spacecraft and hypersonic cruisers of the future will require advanced lightweight thermal protection systems that can provide the dual functionality of...

  11. Ultra-Lightweight Nanocomposite Foams and Sandwich Structures for Space Structures Applications Project (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. Self Deployable Ultra-Lightweight Modular Unit for Habitat Structural Applications Project (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...

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

  14. Ultra-Lightweight High Efficiency Nanostructured Materials and Coatings for Deep Space Mission Environments Project (United States)

    National Aeronautics and Space Administration — NanoSonic has developed a nanostructured spray self-assembly manufacturing method that has resulted in ultra-lightweight (< 0.4g/cc) textile interconnects for...

  15. Lightweight Brick by Carbon Ash from The Mixed Plastic Waste Treatment Plant

    Directory of Open Access Journals (Sweden)

    Chen Kuo-Wei


    Full Text Available This study was designed to investigate the mixed plastic waste from the production of light carbon ash bricks performance. The mixed waste plastic pyrolysis process generated waste - Carbon ash. After extrusion, a Lightweight brick was made by carbon ash, additive and Cement mortar. In general, the set compressive strength and insulation effect of lightweight bricks with carbon ash proportion for significant impact. The set water absorption and thermal conductivity of lightweight bricks with carbon ash proportion for significant impact. The set density of lightweight brick ameliorates with M3824 additive and CM3 cement mortar for significant impact. Under conditions of technology and economic, the results of this study as reference for market-oriented marketing and commercialization of production.

  16. Ultra-Lightweight Self-Deployable SMP Nanocomposite Sandwich for Habitat Applications Project (United States)

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

  17. Lightweight Ultrahigh Temperature CMC-Lined C/C Combustion Chambers, Phase II Project (United States)

    National Aeronautics and Space Administration — NASA and DoD are seeking high-performance, lightweight liquid rocket combustion chambers with future performance goals that cannot be achieved using state-of-the-art...

  18. Efficient Lightweight AC-AC Power Control for Solar UAV Project (United States)

    National Aeronautics and Space Administration — A highly efficient and lightweight dual bridge matrix power controller development is proposed that will provide high performance to a solar powered high altitude...

  19. Silicon Carbide Lightweight Optics With Hybrid Skins for Large Cryo Telescopes Project (United States)

    National Aeronautics and Space Administration — Optical Physics Company (OPC) has developed new silicon carbide (SiC) foam-based optics with hybrid skins that are composite, athermal and lightweight (FOCAL) that...

  20. Silicon Carbide Lightweight Optics With Hybrid Skins for Large Cryo Telescopes Project (United States)

    National Aeronautics and Space Administration — Optical Physics Company (OPC) proposes to manufacture new silicon carbide (SiC) foam-based optics that are composite, athermal and lightweight (FOCAL) that provide...

  1. Scalable, Lightweight, Low-Cost Aero/Electrodynamic Drag Deorbit Module Project (United States)

    National Aeronautics and Space Administration — The proposed effort will develop the "Terminator Tape Deorbit Module", a lightweight, low-cost, scalable de-orbit module that will utilize both aerodynamic drag...

  2. CIRS-lite as a lightweight atmospheric sounder for Earth trace-gas science Project (United States)

    National Aeronautics and Space Administration — CIRS-lite is a lightweight  version of the CIRS 43-kg Fourier transform spectrometer (FTS) currently returning data from Saturn.  CIRS-lite is of interest...

  3. Actively Cooled Silicon Lightweight Mirrors for Far Infrared and Submillimeter Optical Systems Project (United States)

    National Aeronautics and Space Administration — The NASA Space Science Enterprise has 2 themes requiring large, lightweight cryogenic mirrors: Astronomical Search for Origins and Planetary Systems (ASO) and the...

  4. Lightweight Design of an HTS Coil for the VASIMR Experiment Project (United States)

    National Aeronautics and Space Administration — In this Phase II SBIR contract Tai-Yang Research Company of Tennessee proposes to design, fabricate, and test an ultra-lightweight High Temperature Superconducting...

  5. Lightweight Metal Rubber Wire and Cable for Space Power Systems Project (United States)

    National Aeronautics and Space Administration — The objective of this NASA STTR program is to produce ultra-lightweight electrical wire and cable harnesses to reduce the liftoff weight of future space flight...

  6. Method for calculating thermal properties of lightweight floor heating panels based on an experimental setup

    DEFF Research Database (Denmark)

    Weitzmann, Peter; Svendsen, Svend


    Lightweight floor heating systems consist of a plastic tube connected to a heat distribution aluminium plate and are used in wooden floor constructions. The thermal properties of lightweight floor heating systems cannot be described accurately. The reason is a very complex interaction of convection......, radiation and conduction of the heat transfer between pipe and surrounding materials. The European Standard for floor heating, EN1264, does not cover lightweight systems, while the supplemental Nordtest Method VVS127 is aimed at lightweight systems. The thermal properties can be found using tabulated values...... or experiments. Neither includes dynamic properties. This article describes a method to find steady-state and dynamical thermal properties in an experimental setup based on finding a characteristic thermal resistance between pipe and heat transfer plate, which can be directly implemented in a numerical...

  7. Precision Membrane Optical Shell (PMOS) Technology for Lightweight LIDAR Apertures Project (United States)

    National Aeronautics and Space Administration — Precision membrane optical shell (PMOS) technology is an innovative combination of 1) ultra lightweight optically smooth membrane thin films, 2) advanced mold based...

  8. Influence of Mineral Admixtures on the Permeability of Lightweight Aggregate Concrete

    Institute of Scientific and Technical Information of China (English)

    WANG Fazhou; HU Shuguang; DING Qingjun; PENG yanzhou


    The permeability of lightweight aggregate concrete was studied. Some efforts were taken to increase the resistance of lightweight aggregate concrete (LC) to water penetration by using the mineral admixtures of fly ash, granulated blast furnace slag or silica fume. Accelerated chloride penetrability test and liquid atmosphere press method were used to study the anti-permeability of lightweight aggregate concrete. The experimental results show that fly ash, granulated blast furnace slag and silica fume can decrease the permeability of lightweight aggregate concrete, but the effect of granulated blast furnace slag is poor. According to the SEM and pore structure analyzing results,an interface self-reinforcing effect model was presented and the reinforced mechanism of mineral mixture on LC was discussed according to the model described by authors.

  9. Novel Architecture for a Long-Life, Lightweight Venus Lander (United States)

    Bugby, D.; Seghi, S.; Kroliczek, E.; Pauken, M.


    This paper describes a novel concept for an extended lifetime, lightweight Venus lander. Historically, to operate in the 480° C, 90 atm, corrosive, mostly CO2 Venus surface environment, previous landers have relied on thick Ti spherical outer shells and thick layers of internal insulation. But even the most resilient of these landers operated for only about 2 hours before succumbing to the environment. The goal on this project is to develop an architecture that extends lander lifetime to 20-25 hours and also reduces mass compared to the Pioneer Venus mission architecture. The idea for reducing mass is to: (a) contain the science instruments within a spherical high strength lightweight polymer matrix composite (PMC) tank; (b) surround the PMC tank with an annular shell of high performance insulation pre-pressurized to a level that (after landing) will exceed the external Venus surface pressure; and (c) surround the insulation with a thin Ti outer shell that contains only a net internal pressure, eliminating buckling overdesign mass. The combination of the PMC inner tank and thin Ti outer shell is lighter than a single thick Ti outer shell. The idea for extending lifetime is to add the following three features: (i) an expendable water supply that is placed within the insulation or is contained in an additional vessel within the PMC tank; (ii) a thin spherical evaporator shell placed within the insulation a short radial distance from the outer shell; and (iii) a thin heat-intercepting liquid cooled shield placed inboard of the evaporator shell. These features lower the temperature of the insulation below what it would have been with the insulation alone, reducing the internal heat leak and lengthening lifetime. The use of phase change materials (PCMs) inside the PMC tank is also analyzed as a lifetime-extending design option. The paper describes: (1) analytical modeling to demonstrate reduced mass and extended life; (2) thermal conductivity testing of high

  10. Development of a Compact, Efficient Cooling Pump for Space Suit Life Support Systems (United States)

    van Boeyen, Roger; Reeh, Jonathan; Trevino, Luis


    A compact, low-power electrochemically-driven fluid cooling pump is currently being developed by Lynntech, Inc. With no electric motor and minimal lightweight components, the pump is significantly lighter than conventional rotodynamic and displacement pumps. Reliability and robustness is achieved with the absence of rotating or moving components (apart from the bellows). By employing sulfonated polystyrene-based proton exchange membranes, rather than conventional Nafion membranes, a significant reduction in the actuator power consumption was demonstrated. Lynntech also demonstrated that these membranes possess the necessary mechanical strength, durability, and temperature range for long life space operation. The preliminary design for a Phase II prototype pump compares very favorably to the fluid cooling pumps currently used in space suit primary life support systems (PLSSs). Characteristics of the electrochemically-driven pump are described and the benefits of the technology as a replacement for electric motor pumps in mechanically pumped single-phase fluid loops is discussed.

  11. Compact Monitor for Airborne Carbon Dioxide Measurements Project (United States)

    National Aeronautics and Space Administration — Eltron Research & Development proposes the development of a lightweight, battery-powered instrument for accurately and rapidly monitoring the local concentration...

  12. Best practices for making high integrity lightweight metal castings- molten metal composition and cleanliness control

    Institute of Scientific and Technical Information of China (English)

    Qigui Wang


    To make high integrity lightweight metal castings, best practices are required in various stages of casting and heat treatment processes, including liquid metal composition and quality control, casting and gating/riser system design, and process optimization. This paper presents best practices for liquid metal processing and quality assurance of molten metal in both melting and mold ifling. Best practices for other aspects of lightweight metal casting wil be published separately.



    Semenov Vyacheslav Sergeevich; Oreshkin Dmitriy Vladimirovich; Rozovskaya Tamara Alekseevna


    The authors provide their research findings concerning lightweight masonry mortars with hollow glass microspheres and antifreeze admixtures. These mortars are used in the construction of filler structures at negative temperatures. The application of multilayer filler structures causes reduction of their thermal homogeneity factor. Therefore, single-layer filler structures have the strongest potential. There is a need to employ lightweight masonry mortars to ensure the thermal homogeneity of s...

  14. Cost and Operational Effectiveness Analysis (COEA) for the Lightweight Water Purifier (LWP). (United States)


    requirement for a Lightweight Water Purifier (LWP). Data and information from this COEA is intended to support a Milestone Decision Review ( MDR I/I1) planned... MDR ) with suitable information and analysis to enable them to: (1) Select from among the designated Lightweight Water Purifier (LWP) alternatives and...Service field water quality standards contained in Technical Bulletin, Medical ( TB MED 577). The LWP falls within the Combat Service Support (CSS

  15. FEM Simulation of Bending Formability for Laminate Steel/Resin/Steel Lightweight Composite Sheet

    Institute of Scientific and Technical Information of China (English)

    Guancheng Ll; Yonglin KANG


    The ANSYS simulation software was used to analyze the bending formability of laminate steel/resin/steel lightweight composite sheet. The skin steel at external side produces relative slipping-off change during the bending due to its composite structure. The internal stress strain states, materials effect tools parameters and intermediate layer resin of lightweight sheet on slipping-off change were analyzed. The spring back and shear stress state after bending have also been discussed.

  16. Compact Microscope Imaging System Developed (United States)

    McDowell, Mark


    The Compact Microscope Imaging System (CMIS) is a diagnostic tool with intelligent controls for use in space, industrial, medical, and security applications. The CMIS can be used in situ with a minimum amount of user intervention. This system, which was developed at the NASA Glenn Research Center, can scan, find areas of interest, focus, and acquire images automatically. Large numbers of multiple cell experiments require microscopy for in situ observations; this is only feasible with compact microscope systems. CMIS is a miniature machine vision system that combines intelligent image processing with remote control capabilities. The software also has a user-friendly interface that can be used independently of the hardware for post-experiment analysis. CMIS has potential commercial uses in the automated online inspection of precision parts, medical imaging, security industry (examination of currency in automated teller machines and fingerprint identification in secure entry locks), environmental industry (automated examination of soil/water samples), biomedical field (automated blood/cell analysis), and microscopy community. CMIS will improve research in several ways: It will expand the capabilities of MSD experiments utilizing microscope technology. It may be used in lunar and Martian experiments (Rover Robot). Because of its reduced size, it will enable experiments that were not feasible previously. It may be incorporated into existing shuttle orbiter and space station experiments, including glove-box-sized experiments as well as ground-based experiments.

  17. A compact THz imaging system (United States)

    Sešek, Aleksander; Å vigelj, Andrej; Trontelj, Janez


    The objective of this paper is the development of a compact low cost imaging THz system, usable for observation of the objects near to the system and also for stand-off detection. The performance of the system remains at the high standard of more expensive and bulkiest system on the market. It is easy to operate as it is not dependent on any fine mechanical adjustments. As it is compact and it consumes low power, also a portable system was developed for stand-off detection of concealed objects under textile or inside packages. These requirements rule out all optical systems like Time Domain Spectroscopy systems which need fine optical component positioning and requires a large amount of time to perform a scan and the image capture pixel-by-pixel. They are also almost not suitable for stand-off detection due to low output power. In the paper the antenna - bolometer sensor microstructure is presented and the THz system described. Analysis and design guidelines for the bolometer itself are discussed. The measurement results for both near and stand-off THz imaging are also presented.

  18. Compact Visualisation of Video Summaries

    Directory of Open Access Journals (Sweden)

    Ćalić Janko


    Full Text Available This paper presents a system for compact and intuitive video summarisation aimed at both high-end professional production environments and small-screen portable devices. To represent large amounts of information in the form of a video key-frame summary, this paper studies the narrative grammar of comics, and using its universal and intuitive rules, lays out visual summaries in an efficient and user-centered way. In addition, the system exploits visual attention modelling and rapid serial visual presentation to generate highly compact summaries on mobile devices. A robust real-time algorithm for key-frame extraction is presented. The system ranks importance of key-frame sizes in the final layout by balancing the dominant visual representability and discovery of unanticipated content utilising a specific cost function and an unsupervised robust spectral clustering technique. A final layout is created using an optimisation algorithm based on dynamic programming. Algorithm efficiency and robustness are demonstrated by comparing the results with a manually labelled ground truth and with optimal panelling solutions.

  19. Brittle and compaction creep in porous sandstone (United States)

    Heap, Michael; Brantut, Nicolas; Baud, Patrick; Meredith, Philip


    Strain localisation in the Earth's crust occurs at all scales, from the fracture of grains at the microscale to crustal-scale faulting. Over the last fifty years, laboratory rock deformation studies have exposed the variety of deformation mechanisms and failure modes of rock. Broadly speaking, rock failure can be described as either dilatant (brittle) or compactive. While dilatant failure in porous sandstones is manifest as shear fracturing, their failure in the compactant regime can be characterised by either distributed cataclastic flow or the formation of localised compaction bands. To better understand the time-dependency of strain localisation (shear fracturing and compaction band growth), we performed triaxial deformation experiments on water-saturated Bleurswiller sandstone (porosity = 24%) under a constant stress (creep) in the dilatant and compactive regimes, with particular focus on time-dependent compaction band formation in the compactive regime. Our experiments show that inelastic strain accumulates at a constant stress in the brittle and compactive regimes leading to the development of shear fractures and compaction bands, respectively. While creep in the dilatant regime is characterised by an increase in porosity and, ultimately, an acceleration in axial strain to shear failure (as observed in previous studies), compaction creep is characterised by a reduction in porosity and a gradual deceleration in axial strain. The overall deceleration in axial strain, AE activity, and porosity change during creep compaction is punctuated by excursions interpreted as the formation of compaction bands. The growth rate of compaction bands formed during creep is lower as the applied differential stress, and hence background creep strain rate, is decreased, although the inelastic strain required for a compaction band remains constant over strain rates spanning several orders of magnitude. We find that, despite the large differences in strain rate and growth rate

  20. Application of Pinniped Vibrissae to Aeropropulsion (United States)

    Shyam, Vikram; Ameri, Ali; Poinsatte, Philip; Thurman, Douglas; Wroblewski, Adam; Snyder, Christopher


    Vibrissae of Phoca Vitulina (Harbor Seal) and Mirounga Angustirostris (Elephant Seal) possessundulations along their length. Harbor Seal Vibrissae were shown to reduce vortex induced vibrations and reduce dragcompared to appropriately scaled cylinders and ellipses. Samples of Harbor Seal vibrissae, Elephant Seal vibrissae andCalifornia Sea Lion vibrissae were collected from the Marine Mammal Center in California. CT scanning, microscopy and3D scanning techniques were utilized to characterize the whiskers. Computational fluid dynamics simulations of thewhiskers were carried out to compare them to an ellipse and a cylinder. Leading edge parameters from the whiskerswere used to create a 3D profile based on a modern power turbine blade. The NASA SW-2 facility was used to performwind tunnel cascade testing on the 'Seal Blades'. Computational Fluid Dynamics simulations were used to studyincidence angles from -37 to +10 degrees on the aerodynamic performance of the Seal Blade. The tests and simulationswere conducted at a Reynolds number of 100,000. The Seal Blades showed consistent performance improvements overthe baseline configuration. It was determined that a fuel burn reduction of approximately 5 could be achieved for a fixedwing aircraft. Noise reduction potential is also explored

  1. Effects of Palm Fiber on the Mechanical Properties of Lightweight Concrete Crushed Brick

    Directory of Open Access Journals (Sweden)

    Mahyuddin Ramli


    Full Text Available Problem statement: Researches has been conducted worldwide on a large number of natural or artificial lightweight aggregates. In spite of many of the researches of using natural fibers show considerable promise, the use of natural fibers to improve the properties of lightweight concrete still required to be a subject of further research and investigation. Approach: This experimental investigation was carried out to study the properties of lightweight crushed brick concrete containing palm fiber of different volume fractions. An experimental programme was planned in which the tests such as density, compressive strength and flexural strength were conducted to investigate the properties of lightweight crushed brick concrete reinforced by palm fiber. The specimen incorporated different volume fractions of palm fiber, i.e., 0, 0.2, 0.4, 0.6, 0.8 and 1.0%. Results: Tests results showed that the use of this fiber slightly increases the density of lightweight concrete. The use of 0.8% of palm fiber increases the compressive strength and flexural strength by about 13.4 and 16.1% respectively. Conclusion: The results indicated that the use of palm fiber with lightweight crushed brick concrete enhances the mechanical properties of the concrete and the optimization of the palm fiber fractions is required to get the best performance.

  2. Titanium cholla : lightweight, high-strength structures for aerospace applications.

    Energy Technology Data Exchange (ETDEWEB)

    Atwood, Clinton J.; Voth, Thomas Eugene; Taggart, David G. (University of Rhode Island, Kingston, RI); Gill, David Dennis; Robbins, Joshua H.; Dewhurst, Peter (University of Rhode Island, Kingston, RI)


    Aerospace designers seek lightweight, high-strength structures to lower launch weight while creating structures that are capable of withstanding launch loadings. Most 'light-weighting' is done through an expensive, time-consuming, iterative method requiring experience and a repeated design/test/redesign sequence until an adequate solution is obtained. Little successful work has been done in the application of generalized 3D optimization due to the difficulty of analytical solutions, the large computational requirements of computerized solutions, and the inability to manufacture many optimized structures with conventional machining processes. The Titanium Cholla LDRD team set out to create generalized 3D optimization routines, a set of analytically optimized 3D structures for testing the solutions, and a method of manufacturing these complex optimized structures. The team developed two new computer optimization solutions: Advanced Topological Optimization (ATO) and FlexFEM, an optimization package utilizing the eXtended Finite Element Method (XFEM) software for stress analysis. The team also developed several new analytically defined classes of optimized structures. Finally, the team developed a 3D capability for the Laser Engineered Net Shaping{trademark} (LENS{reg_sign}) additive manufacturing process including process planning for 3D optimized structures. This report gives individual examples as well as one generalized example showing the optimized solutions and an optimized metal part.

  3. Lightweight diesel engine designs for commuter type aircraft (United States)

    Brouwers, A. P.


    Conceptual designs and performance of advanced technology lightweight diesel engines, suitable for commuter type aircraft power plants are defined. Two engines are discussed, a 1491 kW (2000 SHP) eight-cylinder engine and a 895 kW (1200 SHP) six-cylinder engine. High performance and related advanced technologies are proposed such as insulated cylinders, very high injection pressures and high compressor and turbine efficiencies. The description of each engine includes concept drawings, a performance analysis, and weight data. Fuel flow data are given for full and partial power up to 7620m altitude. The performance data are also extrapolated over a power range from 671 kW(900SHP) to 1864 kW (2500 SHP). The specific fuel consumption of the 1491 kW (2000 SHP) engine is 182 g/hWh (.299 lb/HPh) at cruise altitude, its weight 620 kg (1365 lb.) and specific weight .415 kg/kW (.683 lb/HP). The specific fuel consumption of the 895 kW (1200 SHP) engine is 187 g/hWh (.308 lb/HPh) at cruise altitude, its weight 465 kg (1025 lb.) and specific weight .520 kg/kW (.854 lb/HP).

  4. Lightweight Low Force Rotary Percussive Coring Tool for Planetary Applications (United States)

    Hironaka, Ross; Stanley, Scott


    A prototype low-force rotary-percussive rock coring tool for use in acquiring samples for geological surveys in future planetary missions was developed. The coring tool could eventually enable a lightweight robotic system to operate from a relatively small (less than 200 kg) mobile or fixed platform to acquire and cache Mars or other planetary rock samples for eventual return to Earth for analysis. To gain insight needed to design an integrated coring tool, the coring ability of commercially available coring bits was evaluated for effectiveness of varying key parameters: weight-on-bit, rotation speed, percussive rate and force. Trade studies were performed for different methods of breaking a core at its base and for retaining the core in a sleeve to facilitate sample transfer. This led to a custom coring tool design which incorporated coring, core breakage, core retention, and core extraction functions. The coring tool was tested on several types of rock and demonstrated the overall feasibility of this approach for robotic rock sample acquisition.

  5. Structural modeling of sandwich structures with lightweight cellular cores

    Institute of Scientific and Technical Information of China (English)

    T. Liu; Z. C. Deng; T. J. Lu


    An effective single layered finite element (FE) computational model is proposed to predict the structural behavior of lightweight sandwich panels having two dimensional (2D) prismatic or three dimensional (3D) truss cores.Three different types of cellular core topology are considered: pyramidal truss core (3D), Kagome truss core (3D) and corrugated core (2D), representing three kinds of material anisotropy: orthotropic, monoclinic and general anisotropic. A homogenization technique is developed to obtain the homogenized macroscopic stiffness properties of the cellular core. In comparison with the results obtained by using detailed FE model, the single layered computational model cangive acceptable predictions for both the static and dynamic behaviors of orthotropic truss core sandwich panels. However, for non-orthotropic 3D truss cores, the predictions are not so well. For both static and dynamic behaviors of a 2D corrugated core sandwich panel, the predictions derived by the single layered computational model is generally acceptable when the size of the unit cell varies within a certain range, with the predictions for moderately strong or strong corrugated cores more accurate than those for weak cores.

  6. Ultra-lightweight, Low Scatter, Large Mirror Technology (United States)

    Bennett, H. E.


    A technique is being developed to fabricate a prototype lightweight composite mirror one meter in diameter. The mandrel, on which the composite mirror will be laid up, is an ultra low expansion quartz glass, TSG, whose thermal expansion coefficient, 10(exp -7)/ degC or less, is similar to that for the composite material itself. The mandrel surface will be super-polished to 6-8 A rms or better, resulting in ten times less scattered light in the visible region than is found in typical astronomical mirrors. We have shown experimentally that mandrel micro-roughnesses of this order can be successfully replicated on composite faceplates. The faceplate is very tough, and does not fracture like a thin glass faceplate. It will be supported by actuators alone, not by the edge of the mirror mount, to avoid non-uniform or non-symmetric influence functions. BOR developed actuators are designed for atmospheric correction, maintenance of optical figure, and minor tip tilt. They have a throw of a centimeter, can be controlled remotely, and have a response time of 1/2 msec. The piezoelectric part of the actuator operates in the 30-70 V range and the differential screw portion has a linearity of about +/-0.1 microns.

  7. Abstracting massive data for lightweight intrusion detection in computer networks

    KAUST Repository

    Wang, Wei


    Anomaly intrusion detection in big data environments calls for lightweight models that are able to achieve real-time performance during detection. Abstracting audit data provides a solution to improve the efficiency of data processing in intrusion detection. Data abstraction refers to abstract or extract the most relevant information from the massive dataset. In this work, we propose three strategies of data abstraction, namely, exemplar extraction, attribute selection and attribute abstraction. We first propose an effective method called exemplar extraction to extract representative subsets from the original massive data prior to building the detection models. Two clustering algorithms, Affinity Propagation (AP) and traditional . k-means, are employed to find the exemplars from the audit data. . k-Nearest Neighbor (k-NN), Principal Component Analysis (PCA) and one-class Support Vector Machine (SVM) are used for the detection. We then employ another two strategies, attribute selection and attribute extraction, to abstract audit data for anomaly intrusion detection. Two http streams collected from a real computing environment as well as the KDD\\'99 benchmark data set are used to validate these three strategies of data abstraction. The comprehensive experimental results show that while all the three strategies improve the detection efficiency, the AP-based exemplar extraction achieves the best performance of data abstraction.

  8. Lightweight construction, a historical challenge; Leichtbau - eine historische Herausforderung

    Energy Technology Data Exchange (ETDEWEB)

    Eigenfeld, K. [Technische Univ. Bergakademie Freiberg (Germany). Giesserei-Inst.


    The paper presents a historical outline of the development of mobility, motor cars, and lightweight construction in an integrated approach. [German] Die Entwicklung technischer Prozesse und Produkte nahm mit Beginn der industriellen Revolution einen vorher nicht gekannten Aufschwung. Mit den daraus resultierenden Veraenderungen in den Lebensgewohnheiten der Menschen hat sich, abgesehen von den elementaren Grundbeduerfnissen, die Notwendigkeit und das Beduerfnis nach Mobilitaet sukzessive herangebildet. Mobilitaet heisst nach der Definition in der damaligen Technik Bewegung durch Maschinen, und Maschinen bestehen aus Werkstoffen. Schon fruehzeitig war bekannt, dass bewegte Werkstoffe wenig Masse besitzen sollen. Die Entwicklung des Leichtbaues laesst sich demzufolge am Fortschritt des Verkehrswesens ablesen und dokumentieren. Dabei spielte, wenn auch nicht aus den gleichen Gruenden wie heute, die Verfuegbarkeit, der Energieeinsatz und die Wiederverwendbarkeit, das 'Recycling', eine wichtige Rolle. Der konstruktive und werkstoffbestimmte Leichtbau laesst sich danach in seiner Entstehung auch als Leitfaden fuer heutige Tendenzen betrachten und vieles, was wir derzeit an Entwicklungsrichtungen diskutieren, hat seine Urspruenge im Beginn des motorisierten Verkehrswesens. Ein Blick in die Historie kann jedoch nie schaden, wenn es darum geht, zukuenftige Aufgaben zu bewaeltigen. (orig.)

  9. Toward lightweight biometric signal processing for wearable devices. (United States)

    Francescon, Roberto; Hooshmand, Mohsen; Gadaleta, Matteo; Grisan, Enrico; Yoon, Seung Keun; Rossi, Michele


    Wearable devices are becoming a natural and economic means to gather biometric data from end users. The massive amount of information that they will provide, unimaginable until a few years ago, owns an immense potential for applications such as continuous monitoring for personalized healthcare and use within fitness applications. Wearables are however heavily constrained in terms of amount of memory, transmission capability and energy reserve. This calls for dedicated, lightweight but still effective algorithms for data management. This paper is centered around lossy data compression techniques, whose aim is to minimize the amount of information that is to be stored on their onboard memory and subsequently transmitted over wireless interfaces. Specifically, we analyze selected compression techniques for biometric signals, quantifying their complexity (energy consumption) and compression performance. Hence, we propose a new class of codebook-based (CB) compression algorithms, designed to be energy efficient, online and amenable to any type of signal exhibiting recurrent patterns. Finally, the performance of the selected and the new algorithm is assessed, underlining the advantages offered by CB schemes in terms of memory savings and classification algorithms.


    Directory of Open Access Journals (Sweden)

    A. Arun


    Full Text Available Remote Patient Monitoring (RPM provides flexible and powerful patient surveillance through wearable devices at anytime and anywhere. This can be achieved by using a Body Sensor Network (BSN, which is deployed on a human body for monitoring the healthcare. The mobile healthcare management with increased feasibility and handiness introduced several noteworthy challenges for the provider, policy makers, patient and hospitals. A significant challenge is to provide round-the-clock healthcare services to those patients who require it via wearable medical devices. In addition to this, the sensors collect the personal medical data where the security and privacy are important components in RPM. As a result, one of the most significant and challenging concern to deal with is how to secure the personal information of the patients and to eliminate their privacy issue. This study presents System on Programmable Chip (SoPC implementation of Remote Patient Monitoring System (RPM with Ultra Lightweight algorithms for security issues. Humming Bird 2 (HB-2, PRESENT and HIGHT algorithms were implemented since the wearable medical devices require fewer areas to achieve portability. The comparison results shows that Degree of Confusion of HB-2 is 50.43 which outstand the other, the efficiency of the entire algorithm implemented in SoPC are higher comparing with conventional Field Programmable Gate Array (FPGA implementation. The comparison was extended and in Particular, power and area consumption of HB-2 is less than PRESENT and HIGHT algorithm, which is more suitable for RPM devices.

  11. SIT: A Lightweight Encryption Algorithm for Secure Internet of Things

    Directory of Open Access Journals (Sweden)

    Muhammad Usman


    Full Text Available The Internet of Things (IoT being a promising technology of the future is expected to connect billions of devices. The increased number of communication is expected to generate mountains of data and the security of data can be a threat. The devices in the architecture are essentially smaller in size and low powered. Conventional encryption algorithms are generally computationally expensive due to their complexity and requires many rounds to encrypt, essentially wasting the constrained energy of the gadgets. Less complex algorithm, however, may compromise the desired integrity. In this paper we propose a lightweight encryption algorithm named as Secure IoT (SIT. It is a 64-bit block cipher and requires 64-bit key to encrypt the data. The architecture of the algorithm is a mixture of feistel and a uniform substitution-permutation network. Simulations result shows the algorithm provides substantial security in just five encryption rounds. The hardware implementation of the algorithm is done on a low cost 8-bit micro-controller and the results of code size, memory utilization and encryption/decryption execution cycles are compared with benchmark encryption algo-rithms. The MATLAB code for relevant simulations is available online at

  12. Structural Lightweight Concrete Production by Using Oil Palm Shell

    Directory of Open Access Journals (Sweden)

    Habibur Rahman Sobuz


    Full Text Available Conventional building materials are widely used in a developing country like Malaysia. This type of material is costly. Oil palm shell (OPS is a type of farming solid waste in the tropical region. This paper aims to investigate strength characteristics and cost analysis of concrete produced using the gradation of OPS 0–50% on conventional coarse aggregate with the mix proportions 1 : 1.65 : 2.45, 1 : 2.5 : 3.3, and 1 : 3.3 : 4.2 by the weight of ordinary Portland cement, river sand, crushed stone, and OPS as a substitution for coarse aggregate. The corresponding w/c ratios were used: 0.45, 0.6, and 0.75, respectively, for the defined mix proportions. Test results indicate that compressive strength of concrete decreased as the percentage of the OPS increased in each mix ratio. Other properties of OPS concrete, namely, modulus of rupture, modulus of elasticity, splitting tensile strength, and density, were also determined and compared to the corresponding properties of conventional concrete. Economic analysis also indicates possible cost reduction of up to 15% due to the use of OPS as coarse aggregate. Finally, it is concluded that the use of OPS has great potential in the production of structural lightweight concrete.

  13. ARC Cache: A solution for lightweight Grid sites in ATLAS

    CERN Document Server

    Garonne, Vincent; The ATLAS collaboration


    Many Grid sites have the need to reduce operational manpower, and running a storage element consumes a large amount of effort. In addition, setting up a new Grid site including a storage element involves a steep learning curve and large investment of time. For these reasons so-called storage-less sites are becoming more popular as a way to provide Grid computing resources with less operational overhead. ARC CE is a widely-used and mature Grid middleware which was designed from the start to be used on sites with no persistent storage element. Instead, it maintains a local self-managing cache of data which retains popular data for future jobs. As the cache is simply an area on a local posix shared filesystem with no external-facing service, it requires no extra maintenance. The cache can be scaled up as required by increasing the size of the filesystem or adding new filesystems. This paper describes how ARC CE and its cache are an ideal solution for lightweight Grid sites in the ATLAS experiment, and the integr...

  14. Lightweight link dimensioning using sFlow sampling

    DEFF Research Database (Denmark)

    de Oliviera Schmidt, Ricardo; Sadre, Ramin; Sperotto, Anna;


    Operators use link dimensioning to provision network links. In practice, traffic averages are obtained via SNMP are used to roughly estimate required capacity. More accurate solutions often require traffic statistics easily obtained from packet captures, e.g. variance. However, packet capturing m...... of sampling algorithm, the error introduced by scaling the traffic variance yields more conservative results that cope with short-term traffic fluctuations....... not be trivial in high-speed links. Aiming scalability, operators often deploy packet sampling on monitoring, but little is known how it affects link dimensioning. In this paper we assess the feasibility of lightweight link dimensioning using sFlow, which is a widely-deployed traffic monitoring tool. We...... implement sFlow sampling algorithm and use a previously proposed and validated dimensioning formula that needs traffic variance. We validate our approach using packet captures from real networks. Results show that the proposed procedure is successful for a range of sampling rates and that, due to randomness...

  15. Structural modeling of sandwich structures with lightweight cellular cores (United States)

    Liu, T.; Deng, Z. C.; Lu, T. J.


    An effective single layered finite element (FE) computational model is proposed to predict the structural behavior of lightweight sandwich panels having two dimensional (2D) prismatic or three dimensional (3D) truss cores. Three different types of cellular core topology are considered: pyramidal truss core (3D), Kagome truss core (3D) and corrugated core (2D), representing three kinds of material anisotropy: orthotropic, monoclinic and general anisotropic. A homogenization technique is developed to obtain the homogenized macroscopic stiffness properties of the cellular core. In comparison with the results obtained by using detailed FE model, the single layered computational model can give acceptable predictions for both the static and dynamic behaviors of orthotropic truss core sandwich panels. However, for non-orthotropic 3D truss cores, the predictions are not so well. For both static and dynamic behaviors of a 2D corrugated core sandwich panel, the predictions derived by the single layered computational model is generally acceptable when the size of the unit cell varies within a certain range, with the predictions for moderately strong or strong corrugated cores more accurate than those for weak cores.

  16. A Light-Weight Rainbow Signature Scheme for WSN

    Directory of Open Access Journals (Sweden)

    Min Zhang


    Full Text Available Since the wireless sensor network (WSN is limited by power, computation capability and storage resources, it is difficult for the existed cryptographic schemes which are based on the traditional symmetric or public key cryptography to adapt to these restrictions. Till  now, most studies are based on the Elliptic Digital Signature  Algorithm (ECDSA, however, which have heavy energy consumption and cost much verification time, they are still  not suitable for the WSN. Thus it is necessary to find a new cryptography to provide the security for the WSN. In this  paper, firstly, we propose a light-weight rainbow signature (LWRS scheme based on Shamir's minus method, and the performances of it has been evaluated with respect to the memory and computation time. Secondly, by choosing the proper number of variables, we use the scheme between the nodes or between the WSN and the business platform of the internet of things. Meanwhile, we set up the layer of the LWRS the same as that of the cluster WSN. That is, the ordinary node has the lowest energy and corresponds to the first layer of the LWRS scheme. Finally, we give the security analysis of the LWRS scheme. More specifically speaking, by choosing the appropriate number of oil-vinegar variables, our scheme can resist general attacks, rank reduction attacks and oil-vinegar attacks, etc.

  17. Modeling chloride penetration into concrete with light-weight aggregates

    Energy Technology Data Exchange (ETDEWEB)

    Maage, M.; Helland, S.; Carlsen, J. E. [SELMER ASA, Oslo (Norway)


    Results of a program of studies designed to provide input to a model for estimating the initiation period of reinforcement corrosion and to document chloride ingress into various practical concretes made with light-weight aggregates, depending on a number of variables in curing and exposure conditions, as well as concrete composition and materials, are discussed. Variables included curing time before exposure; curing temperature; exposure temperature and time; type of exposure; and type of binder. Results achieved correlate well with the initial hypothesis i.e. that the achieved chloride coefficient decreases with increasing exposure time and also with increasing curing time.Surface chloride content as the environmental load, was shown to increase with exposure time during the first years, and decrease with increased curing time and exposure temperature. The achieved diffusion coefficient was found to be independent of curing and exposure temperature, but decreased with longer exposure time and the addition of slag. Increasing the salt concentration in the exposure water and the introduction of slag increased the time dependency of the achieved diffusion coefficient. 11 refs., 2 tabs., 7 figs.

  18. Fly ash-based geopolymer lightweight concrete using foaming agent. (United States)

    Al Bakri Abdullah, Mohd Mustafa; Hussin, Kamarudin; Bnhussain, Mohamed; Ismail, Khairul Nizar; Yahya, Zarina; Razak, Rafiza Abdul


    In this paper, we report the results of our investigation on the possibility of producing foam concrete by using a geopolymer system. Class C fly ash was mixed with an alkaline activator solution (a mixture of sodium silicate and NaOH), and foam was added to the geopolymeric mixture to produce lightweight concrete. The NaOH solution was prepared by dilute NaOH pellets with distilled water. The reactives were mixed to produce a homogeneous mixture, which was placed into a 50 mm mold and cured at two different curing temperatures (60 °C and room temperature), for 24 hours. After the curing process, the strengths of the samples were tested on days 1, 7, and 28. The water absorption, porosity, chemical composition, microstructure, XRD and FTIR analyses were studied. The results showed that the sample which was cured at 60 °C (LW2) produced the maximum compressive strength for all tests, (11.03 MPa, 17.59 MPa, and 18.19 MPa) for days 1, 7, and 28, respectively. Also, the water absorption and porosity of LW2 were reduced by 6.78% and 1.22% after 28 days, respectively. The SEM showed that the LW2 sample had a denser matrix than LW1. This was because LW2 was heat cured, which caused the geopolymerization rate to increase, producing a denser matrix. However for LW1, microcracks were present on the surface, which reduced the compressive strength and increased water absorption and porosity.

  19. Quire: Lightweight Provenance for Smart Phone Operating Systems

    CERN Document Server

    Dietz, Michael; Pisetsky, Yuliy; Shu, Anhei; Wallach, Dan S


    Smartphone apps often run with full privileges to access the network and sensitive local resources, making it difficult for remote systems to have any trust in the provenance of network connections they receive. Even within the phone, different apps with different privileges can communicate with one another, allowing one app to trick another into improperly exercising its privileges (a Confused Deputy attack). In Quire, we engineered two new security mechanisms into Android to address these issues. First, we track the call chain of IPCs, allowing an app the choice of operating with the diminished privileges of its callers or to act explicitly on its own behalf. Second, a lightweight signature scheme allows any app to create a signed statement that can be verified anywhere inside the phone. Both of these mechanisms are reflected in network RPCs, allowing remote systems visibility into the state of the phone when an RPC is made. We demonstrate the usefulness of Quire with two example applications. We built an a...

  20. Light-weight radioisotope heater unit (LWRHU) impact tests (United States)

    Reimus, M. A. H.; Rinehart, G. H.; Herrera, A.; Lopez, B.; Lynch, C.; Moniz, P.


    The light-weight radioisotope heater unit (LWRHU) is a 238PuO2-fueled heat source designed to provide one thermal watt in each of various locations on a spacecraft. Los Alamos National Laboratory designed, fabricated, and safety tested the LWRHU. The heat source consists of a hot-pressed 238PuO2 fuel pellet, a Pt-30Rh vented capsule, a pyrolytic graphite insulator, and a fineweave-pierced fabric graphite aeroshell assembly. To compare the performance of the LWRHUs fabricated for the Cassini mission with the performance of those fabricated for the Galileo mission, and to determine a failure threshold, two types of impact tests were conducted. A post-reentry impact test was performed on one of 180 flight-quality units produced for the Cassini mission and a series of sequential impact tests using simulant-fueled LWRHU capsules were conducted respectively. The results showed that deformation and fuel containment of the impacted Cassini LWRHU was similar to that of a previously tested Galileo LWRHU. Both units sustained minimal deformation of the aeroshell and fueled capsule; the fuel was entirely contained by the platinum capsule. Sequential impacting, in both end-on and side-on orientations, resulted in increased damage with each subsequent impact. Sequential impacting of the LWRHU appears to result in slightly greater damage than a single impact at the final impact velocity of 50 m/s.

  1. Mechanical, Thermal and Functional Properties of Green Lightweight Foamcrete

    Directory of Open Access Journals (Sweden)

    Md Azree Othuman Mydin


    Full Text Available In recent times, the construction industry has revealed noteworthy attention in the use of lightweight foamcrete as a building material due to its many favourable characteristics such as lighter weight, easy to fabricate, durable and cost effective. Foamcrete is a material consisting of Portland cement paste or cement filler matrix (mortar with a homogeneous pore structure created by introducing air in the form of small bubbles. With a proper control in dosage of foam and methods of production, a wide range of densities (400 – 1600 kg/m 3 of foamcrete can be produced thus providing flexibility for application such as structural elements, partition, insulating materials and filling grades. Foamcrete has so far been applied primarily as a filler material in civil engineering works. However, its good thermal and acoustic performance indicates its strong potential as a material in building construction. The focus of this paper is to classify literature on foamcrete in terms of its mechanical, thermal and functional properties.

  2. Lightweight Proofs of Retrievability for Electronic Evidence in Cloud

    Directory of Open Access Journals (Sweden)

    Hongyao Deng


    Full Text Available Proofs of Retrievability (PoR is one of the basic functions of electronic evidence preservation center in cloud. This paper proposes two PoR schemes to execute the workflow of evidence preservation center, which are named Finer Grained Proofs of Retrievability (FG-PoR and More Lightweight Proofs of Retrievability (ML-PoR. The two PoR schemes do not use multi-replication technology or erasure code technology, but employ the verification tags and signatures to implement provable data possession and data recovery dual functions. When some data blocks have been lost in Archive Storage Area (ASA, FG-PoR can recover each data block of evidence matrix, but ML-PoR can only recover a column of evidence matrix. The analysis results show our two PoR schemes do not only provide the integrity verification guarantee but also have robust recovery guarantee to electronic evidence in cloud. The two schemes can allow for lower computation and storage costs than other similar schemes; moreover, ML-PoR can provide lower costs than FG-PoR.

  3. Towards a Certified Lightweight Array Bound Checker for Java Bytecode (United States)

    Pichardie, David


    Dynamic array bound checks are crucial elements for the security of a Java Virtual Machines. These dynamic checks are however expensive and several static analysis techniques have been proposed to eliminate explicit bounds checks. Such analyses require advanced numerical and symbolic manipulations that 1) penalize bytecode loading or dynamic compilation, 2) complexify the trusted computing base. Following the Foundational Proof Carrying Code methodology, our goal is to provide a lightweight bytecode verifier for eliminating array bound checks that is both efficient and trustable. In this work, we define a generic relational program analysis for an imperative, stackoriented byte code language with procedures, arrays and global variables and instantiate it with a relational abstract domain as polyhedra. The analysis has automatic inference of loop invariants and method pre-/post-conditions, and efficient checking of analysis results by a simple checker. Invariants, which can be large, can be specialized for proving a safety policy using an automatic pruning technique which reduces their size. The result of the analysis can be checked efficiently by annotating the program with parts of the invariant together with certificates of polyhedral inclusions. The resulting checker is sufficiently simple to be entirely certified within the Coq proof assistant for a simple fragment of the Java bytecode language. During the talk, we will also report on our ongoing effort to scale this approach for the full sequential JVM.

  4. Study of water infiltration in a lightweight green roof substrate (United States)

    Tomankova, Klara; Holeckova, Martina; Jelinkova, Vladimira; Snehota, Michal


    Green roofs have a positive impact on the environment (e.g. improving microclimate and air quality in cities, reducing solar absorbance and storm water). A laboratory infiltration experiment was conducted on the narrow flume serving as 2D vertical model of a green roof. The lightweight Optigreen substrate Type M was used (depth of 20 cm). The front wall of the flume was transparent and inspected by digital camera. The experiment was designed to measure pressure head, volumetric water content and calculate water retention in the substrate. Experiment comprised three artificial rainfall intensities with different values of initial water content of the substrate. The experimental results confirmed that green roofs have the ability to retain rainwater and thus have a beneficial effect on reducing runoff. In the experiment with the artificial 10 minutes rainfall event (total precipitation of 29 mm), the air dry substrate retained 95.9 % of precipitation. On the other hand for moist initial condition 4.2 % of precipitations amount was captured in the substrate. Additionally, the analysis of images taken during the experiment confirmed preferential flow and uneven advancement of the wetting front. The research was realized as a part of the University Centre for Energy Efficient Buildings supported by the EU and with financial support from the Czech Science Foundation under project number 14-10455P.

  5. Lightweight distributed computing for intraoperative real-time image guidance (United States)

    Suwelack, Stefan; Katic, Darko; Wagner, Simon; Spengler, Patrick; Bodenstedt, Sebastian; Röhl, Sebastian; Dillmann, Rüdiger; Speidel, Stefanie


    In order to provide real-time intraoperative guidance, computer assisted surgery (CAS) systems often rely on computationally expensive algorithms. The real-time constraint is especially challenging if several components such as intraoperative image processing, soft tissue registration or context aware visualization are combined in a single system. In this paper, we present a lightweight approach to distribute the workload over several workstations based on the OpenIGTLink protocol. We use XML-based message passing for remote procedure calls and native types for transferring data such as images, meshes or point coordinates. Two different, but typical scenarios are considered in order to evaluate the performance of the new system. First, we analyze a real-time soft tissue registration algorithm based on a finite element (FE) model. Here, we use the proposed approach to distribute the computational workload between a primary workstation that handles sensor data processing and visualization and a dedicated workstation that runs the real-time FE algorithm. We show that the additional overhead that is introduced by the technique is small compared to the total execution time. Furthermore, the approach is used to speed up a context aware augmented reality based navigation system for dental implant surgery. In this scenario, the additional delay for running the computationally expensive reasoning server on a separate workstation is less than a millisecond. The results show that the presented approach is a promising strategy to speed up real-time CAS systems.

  6. Lightweight Radiator for in Space Nuclear Electric Propulsion (United States)

    Craven, Paul; Tomboulian, Briana; SanSoucie, Michael


    Nuclear electric propulsion (NEP) is a promising option for high-speed in-space travel due to the high energy density of nuclear fission power sources and efficient electric thrusters. Advanced power conversion technologies may require high operating temperatures and would benefit from lightweight radiator materials. Radiator performance dictates power output for nuclear electric propulsion systems. Game-changing propulsion systems are often enabled by novel designs using advanced materials. Pitch-based carbon fiber materials have the potential to offer significant improvements in operating temperature, thermal conductivity, and mass. These properties combine to allow advances in operational efficiency and high temperature feasibility. An effort at the NASA Marshall Space Flight Center to show that woven high thermal conductivity carbon fiber mats can be used to replace standard metal and composite radiator fins to dissipate waste heat from NEP systems is ongoing. The goals of this effort are to demonstrate a proof of concept, to show that a significant improvement of specific power (power/mass) can be achieved, and to develop a thermal model with predictive capabilities making use of constrained input parameter space. A description of this effort is presented.

  7. Novel light-weight materials for shielding gamma ray (United States)

    Chen, Shuo; Bourham, Mohamed; Rabiei, Afsaneh


    A comparison of gamma ray attenuation effectiveness of bulk aluminum, close-cell composite metal foams and open-cell aluminum foam infiltrated with variety of second phase materials were investigated and reported in this study. Mass attenuation coefficients for six sets of samples with three different areal densities of 2, 5 and 10 g/cm2 were determined at photon energies of 0.060, 0.662, 1.173, and 1.332 MeV. Theoretical values were calculated using XCOM software package. A complete agreement was observed between experimental and theoretical results. It is observed that close-cell composite metal foams exhibit a better shielding capability compared to open-cell Al foam with fillers. It is also observed that close-cell composite metal foams offer superior shielding effectiveness compared to bulk aluminum for energies below 0.662 MeV, the mass attenuation coefficients of steel-steel composite metal foam and Al-steel composite metal foam were measured 400 and 300% higher than that of aluminum A356. This study indicates the potential of utilizing the light-weight composite metal foams as shielding material replacing current heavy materials used for attenuation of low energy gamma ray with additional advantages such as high energy absorption and excellent heat rejection capabilities.

  8. Baryon currents in QCD with compact dimensions

    CERN Document Server

    Lucini, B; Pica, C; Lucini, Biagio; Patella, Agostino; Pica, Claudio


    On a compact space with non-trivial cycles, for sufficiently small values of the radii of the compact dimensions, SU(N) gauge theories coupled with fermions in the fundamental representation spontaneously break charge conjugation, time reversal and parity. We show at one loop in perturbation theory that physical signature for this phenomenon is a non-zero baryonic current wrapping around the compact directions. The persistence of this current beyond the perturbative regime is checked by lattice simulations.

  9. On compact generation of some deformed surfaces

    CERN Document Server

    Lowen, Wendy


    We obtain a theorem which allows to prove compact generation of derived categories of Grothendieck categories, based upon certain coverings by localizations. This theorem follows from an application of Rouquier's cocovering theorem in the triangulated context, and it implies Neeman's result on compact generation of quasi-compact separated schemes. We investigate applications of our theorem to non-commutative deformations of such schemes. In general there are obstructions, but for instance our approach yields compact generation of all first order deformations of quasi-projective surfaces.

  10. Compact oleic acid in HAMLET. (United States)

    Fast, Jonas; Mossberg, Ann-Kristin; Nilsson, Hanna; Svanborg, Catharina; Akke, Mikael; Linse, Sara


    HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a complex between alpha-lactalbumin and oleic acid that induces apoptosis in tumor cells, but not in healthy cells. Heteronuclear nuclear magnetic resonance (NMR) spectroscopy was used to determine the structure of 13C-oleic acid in HAMLET, and to study the 15N-labeled protein. Nuclear Overhauser enhancement spectroscopy shows that the two ends of the fatty acid are in close proximity and close to the double bond, indicating that the oleic acid is bound to HAMLET in a compact conformation. The data further show that HAMLET is a partly unfolded/molten globule-like complex under physiological conditions.

  11. Compact RFID Enabled Moisture Sensor

    Directory of Open Access Journals (Sweden)

    U. H. Khan


    Full Text Available This research proposes a novel, low-cost RFID tag sensor antenna implemented using commercially available Kodak photo-paper. The aim of this paper is to investigate the possibility of stable, RFID centric communication under varying moisture levels. Variation in the frequency response of the RFID tag in presence of moisture is used to detect different moisture levels. Combination of unique jaw shaped contours and T-matching network is used for impedance matching which results in compact size and minimal ink consumption. Proposed tag is 1.4 × 9.4 cm2 in size and shows optimum results for various moisture levels upto 45% in FCC band with a bore sight read range of 12.1 m.

  12. Saloplastics: processing compact polyelectrolyte complexes. (United States)

    Schaaf, Pierre; Schlenoff, Joseph B


    Polyelectrolyte complexes (PECs) are prepared by mixing solutions of oppositely charged polyelectrolytes. These diffuse, amorphous precipitates may be compacted into dense materials, CoPECs, by ultracentrifugation (ucPECs) or extrusion (exPECs). The presence of salt water is essential in plasticizing PECs to allow them to be reformed and fused. When hydrated, CoPECs are versatile, rugged, biocompatible, elastic materials with applications including bioinspired materials, supports for enzymes and (nano)composites. In this review, various methods for making CoPECs are described, as well as fundamental responses of CoPEC mechanical properties to salt concentration. Possible applications as synthetic cartilage, enzymatically active biocomposites, self-healing materials, and magnetic nanocomposites are presented.

  13. CIM—Compact intensity modulation (United States)

    Bleuel, M.; Lang, E.; Gähler, R.; Lal, J.


    Compact intensity modulation (CIM), a new method to modulate the intensity of a neutron beam is demonstrated. CIM allows the production of arbitrary signals where the focus point can be chosen and changed without any constraints. A novel feature in this technique compared to spin echo techniques is that the neutron polarization is kept parallel or anti-parallel to the static fields during the passage through the magnetic fields and the beating pattern at the detector is produced by an amplitude modulation (AM) of the adiabatic RF-spin flippers rather than Larmor precession like in neutron spin echo (NSE) instruments; thus, the achievable contrast is very high and the instrument resolution can be changed very quickly. This gives the fascinating possibility at pulsed neutron sources to sweep the modulation frequency of the flippers in order to increase dynamic resolution range during the same neutron pulse.

  14. Gravitational waves from compact objects

    Institute of Scientific and Technical Information of China (English)

    José Antonio de Freitas Pacheco


    Large ground-based laser beam interferometers are presently in operation both in the USA (LIGO) and in Europe (VIRGO) and potential sources that might be detected by these instruments are revisited. The present generation of detectors does not have a sensitivity high enough to probe a significant volume of the universe and,consequently, predicted event rates are very low. The planned advanced generation of interferometers will probably be able to detect, for the first time, a gravitational signal. Advanced LIGO and EGO instruments are expected to detect few (some): binary coalescences consisting of either two neutron stars, two black holes or a neutron star and a black hole. In space, the sensitivity of the planned LISA spacecraft constellation will allow the detection of the gravitational signals, even within a "pessimistic" range of possible signals, produced during the capture of compact objects by supermassive black holes, at a rate of a few tens per year.

  15. Studies of accelerated compact toruses

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, C.W.; Eddleman, J.; Hammer, J.H.


    In an earlier publication we considered acceleration of plasma rings (Compact Torus). Several possible accelerator configurations were suggested and the possibility of focusing the accelerated rings was discussed. In this paper we consider one scheme, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focusing) during acceleration. Because the allowable acceleration force, F/sub a/ = kappaU/sub m//R where (kappa < 1), increases as R/sup -2/, the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case, however, since the accelerating flux can expand as the ring moves, most of the accelerating field energy can be converted into kinetic energy of the ring leading to high efficiency.

  16. Spiral Inflector For Compact Cyclotron

    CERN Document Server

    Karamysheva, G A


    Compact cyclotron for explosives detection by nuclear resonance absorption of γ-rays in nitrogen is under development [1] Cyclotron will be equipped with the external ion source. The injection system consists of a double-drift beam bunching system, a spiral inflector, beam diagnostics, focusing and adjustment elements [2]. The spiral inflector for ion bending from axial to median plane is used. Computer model of spiral inflector for the Customs cyclotron is developed. 3D electrostatic field calculations of the designed inflector are performed. Calculated electric field map and magnetic field map of the cyclotron [3] are used for beam dynamic simulations. Numeric simulations are carried out for 500 particles using code for calculation of particle dynamics by integration of differential equations in Cartesian coordinate system written in MATLAB. Direct Coulomb particle-to-particle method is used to take into account space-charge effects.

  17. Compact Digital High Voltage Charger

    CERN Document Server

    Li, Ge


    The operation of classical resonant circuit developed for the pulse energizing is investigated. The HV pulse or generator is very compact by a soft switching circuit made up of IGBT working at over 30 kHZ. The frequencies of macro pulses andμpulses can be arbitrarily tuned below resonant frequency to digitalize the HV pulse power. Theμpulses can also be connected by filter circuit to get the HVDC power. The circuit topology is given and its novel control logic is analyzed by flowchart. The circuit is part of a system consisting of a AC or DC LV power supply, a pulse transformer, the pulse generator implemented by LV capacitor and leakage inductance of the transformer, a HV DC or pulse power supply and the charged HV capacitor of the modulators.

  18. A Compact UWB Diversity Antenna

    Directory of Open Access Journals (Sweden)

    Hui Zhao


    Full Text Available A compact printed ultrawideband (UWB diversity antenna with a size of 30 mm × 36 mm operating at a frequency range of 3.1–10.6 GHz is proposed. The antenna is composed of two semielliptical monopoles fed by two microstrip lines. Two semicircular slots, two rectangular slots, and one stub are introduced in the ground plane to adjust the impedance bandwidth of the antenna and improve the isolation between two feeding ports. The simulated and measured results show that impedance bandwidth of the proposed antenna can cover the whole UWB band with a good isolation of < −15 dB. The radiation patterns, peak antenna gain, and envelope correlation coefficient are also measured and discussed. The measured results show that the proposed antenna can be a good candidate for some portable MIMO/diversity UWB applications.

  19. Compact Microwave Fourier Spectrum Analyzer (United States)

    Savchenkov, Anatoliy; Matsko, Andrey; Strekalov, Dmitry


    A compact photonic microwave Fourier spectrum analyzer [a Fourier-transform microwave spectrometer, (FTMWS)] with no moving parts has been proposed for use in remote sensing of weak, natural microwave emissions from the surfaces and atmospheres of planets to enable remote analysis and determination of chemical composition and abundances of critical molecular constituents in space. The instrument is based on a Bessel beam (light modes with non-zero angular momenta) fiber-optic elements. It features low power consumption, low mass, and high resolution, without a need for any cryogenics, beyond what is achievable by the current state-of-the-art in space instruments. The instrument can also be used in a wide-band scatterometer mode in active radar systems.

  20. General Relativity&Compact Stars

    Energy Technology Data Exchange (ETDEWEB)

    Glendenning, Norman K.


    Compact stars--broadly grouped as neutron stars and white dwarfs--are the ashes of luminous stars. One or the other is the fate that awaits the cores of most stars after a lifetime of tens to thousands of millions of years. Whichever of these objects is formed at the end of the life of a particular luminous star, the compact object will live in many respects unchanged from the state in which it was formed. Neutron stars themselves can take several forms--hyperon, hybrid, or strange quark star. Likewise white dwarfs take different forms though only in the dominant nuclear species. A black hole is probably the fate of the most massive stars, an inaccessible region of spacetime into which the entire star, ashes and all, falls at the end of the luminous phase. Neutron stars are the smallest, densest stars known. Like all stars, neutron stars rotate--some as many as a few hundred times a second. A star rotating at such a rate will experience an enormous centrifugal force that must be balanced by gravity or else it will be ripped apart. The balance of the two forces informs us of the lower limit on the stellar density. Neutron stars are 10{sup 14} times denser than Earth. Some neutron stars are in binary orbit with a companion. Application of orbital mechanics allows an assessment of masses in some cases. The mass of a neutron star is typically 1.5 solar masses. They can therefore infer their radii: about ten kilometers. Into such a small object, the entire mass of our sun and more, is compressed.

  1. Elongated polyproline motifs facilitate enamel evolution through matrix subunit compaction.

    Directory of Open Access Journals (Sweden)

    Tianquan Jin


    Full Text Available Vertebrate body designs rely on hydroxyapatite as the principal mineral component of relatively light-weight, articulated endoskeletons and sophisticated tooth-bearing jaws, facilitating rapid movement and efficient predation. Biological mineralization and skeletal growth are frequently accomplished through proteins containing polyproline repeat elements. Through their well-defined yet mobile and flexible structure polyproline-rich proteins control mineral shape and contribute many other biological functions including Alzheimer's amyloid aggregation and prolamine plant storage. In the present study we have hypothesized that polyproline repeat proteins exert their control over biological events such as mineral growth, plaque aggregation, or viscous adhesion by altering the length of their central repeat domain, resulting in dramatic changes in supramolecular assembly dimensions. In order to test our hypothesis, we have used the vertebrate mineralization protein amelogenin as an exemplar and determined the biological effect of the four-fold increased polyproline tandem repeat length in the amphibian/mammalian transition. To study the effect of polyproline repeat length on matrix assembly, protein structure, and apatite crystal growth, we have measured supramolecular assembly dimensions in various vertebrates using atomic force microscopy, tested the effect of protein assemblies on crystal growth by electron microscopy, generated a transgenic mouse model to examine the effect of an abbreviated polyproline sequence on crystal growth, and determined the structure of polyproline repeat elements using 3D NMR. Our study shows that an increase in PXX/PXQ tandem repeat motif length results (i in a compaction of protein matrix subunit dimensions, (ii reduced conformational variability, (iii an increase in polyproline II helices, and (iv promotion of apatite crystal length. Together, these findings establish a direct relationship between polyproline tandem

  2. JP-8 catalytic cracking for compact fuel processors (United States)

    Campbell, Timothy J.; Shaaban, Aly H.; Holcomb, Franklin H.; Salavani, Reza; Binder, Michael J.

    In processing heavier hydrocarbons such as military logistic fuels (JP-4, JP-5, JP-8, and JP-100), kerosene, gasoline, and diesel to produce hydrogen for fuel cell use, several issues arise. First, these fuels have high sulfur content, which can poison and deactivate components of the reforming process and the fuel cell stack; second, these fuels may contain non-volatile residue (NVR), up to 1.5 vol.%, which could potentially accumulate in a fuel processor; and third is the high coking potential of heavy hydrocarbons. Catalytic cracking of a distillate fuel prior to reforming can resolve these issues. Cracking using an appropriate catalyst can convert the various heavy organosulfur species in the fuel to lighter sulfur species such as hydrogen sulfide (H 2S), facilitating subsequent sulfur adsorption on zinc oxide (ZnO). Cracking followed by separation of light cracked gas from heavies effectively eliminates non-volatile aromatic species. Catalytic cracking can also convert heavier hydrocarbons to lights (C 1-C 3) at high conversion, which reduces the potential for coke formation in the reforming process. In this study, two types of catalysts were compared for JP-8 cracking performance: commercially-available zeolite materials similar to catalysts formulated for fluidized catalytic cracking (FCC) processes, and a novel manganese/alumina catalyst, which was previously reported to provide high selectivity to lights and low coke yield. Experiments were designed to test each catalyst's effectiveness under the high space velocity conditions necessary for use in compact, lightweight fuel processor systems. Cracking conversion results, as well as sulfur and hydrocarbon distributions in the light cracked gas, are presented for the two catalysts to provide a performance comparison.

  3. Combination of lightweight elements and nanostructured materials for batteries. (United States)

    Chen, Jun; Cheng, Fangyi


    In a society that increasingly relies on mobile electronics, demand is rapidly growing for both primary and rechargeable batteries that power devices from cell phones to vehicles. Existing batteries utilize lightweight active materials that use electrochemical reactions of ions such as H(+), OH(-) and Li(+)/Mg(2+) to facilitate energy storage and conversion. Ideal batteries should be inexpensive, have high energy density, and be made from environmentally friendly materials; batteries based on bulk active materials do not meet these requirements. Because of slow electrode process kinetics and low-rate ionic diffusion/migration, most conventional batteries demonstrate huge gaps between their theoretical and practical performance. Therefore, efforts are underway to improve existing battery technologies and develop new electrode reactions for the next generation of electrochemical devices. Advances in electrochemistry, surface science, and materials chemistry are leading to the use of nanomaterials for efficient energy storage and conversion. Nanostructures offer advantages over comparable bulk materials in improving battery performance. This Account summarizes our progress in battery development using a combination of lightweight elements and nanostructured materials. We highlight the benefits of nanostructured active materials for primary zinc-manganese dioxide (Zn-Mn), lithium-manganese dioxide (Li-Mn), and metal (Mg, Al, Zn)-air batteries, as well as rechargeable lithium ion (Li-ion) and nickel-metal hydride (Ni-MH) batteries. Through selected examples, we illustrate the effect of structure, shape, and size on the electrochemical properties of electrode materials. Because of their numerous active sites and facile electronic/ionic transfer and diffusion, nanostructures can improve battery efficiency. In particular, we demonstrate the properties of nanostructured active materials including Mg, Al, Si, Zn, MnO(2), CuV(2)O(6), LiNi(0.8)Co(0.2)O(2), LiFePO(4), Fe(2)O(3

  4. Effect of water absorption by the aggregate on properties of high-strength lightweight concrete

    Energy Technology Data Exchange (ETDEWEB)

    Punkki, J.


    Recently, high-strength lightweight concrete has become an interesting building material for the offshore oil industry. This doctoral thesis presents an experimental investigation of the effect of water absorption by three different types of lightweight aggregates. One type did not show any water absorption ability at all and so represented no problem to the concrete production. For the two other high-strength aggregates, which were of more conventional types, the water absorption depended not only on the properties of the aggregates, but also on the concrete mixing procedure and the properties of the fresh cement paste. When water absorbing lightweight aggregate was used in a dry condition, the workability of the concrete was significantly reduced by the water absorption of the aggregate. This effect was not present when prewetted aggregate was used. The water absorption by the lightweight aggregate also affected the early compressive strength of concrete. After one day, dry aggregate gave on the average 10 MPa higher compressive strength than did prewetted aggregate. The strength-density ratio was affected by the moisture condition of the aggregate. Dry lightweight aggregate gave 9 MPa higher compressive strength at a density of 2000 kg/m{sup 3} compared to that of prewetted aggregate. The water absorption by the lightweight also affected the microstructure of the hardened concrete. Dry lightweight aggregate gave a slightly better microstructure than normal weight aggregate. The results indicate that the use of prewetted aggregate adversely affected the transition zone between the aggregate and the cement paste. 69 refs., 58 figs., 42 tabs.

  5. Fly Ash-based Geopolymer Lightweight Concrete Using Foaming Agent

    Directory of Open Access Journals (Sweden)

    Rafiza Abdul Razak


    Full Text Available In this paper, we report the results of our investigation on the possibility of producing foam concrete by using a geopolymer system. Class C fly ash was mixed with an alkaline activator solution (a mixture of sodium silicate and NaOH, and foam was added to the geopolymeric mixture to produce lightweight concrete. The NaOH solution was prepared by dilute NaOH pellets with distilled water. The reactives were mixed to produce a homogeneous mixture, which was placed into a 50 mm mold and cured at two different curing temperatures (60 °C and room temperature, for 24 hours. After the curing process, the strengths of the samples were tested on days 1, 7, and 28. The water absorption, porosity, chemical composition, microstructure, XRD and FTIR analyses were studied. The results showed that the sample which was cured at 60 °C (LW2 produced the maximum compressive strength for all tests, (11.03 MPa, 17.59 MPa, and 18.19 MPa for days 1, 7, and 28, respectively. Also, the water absorption and porosity of LW2 were reduced by 6.78% and 1.22% after 28 days, respectively. The SEM showed that the LW2 sample had a denser matrix than LW1. This was because LW2 was heat cured, which caused the geopolymerization rate to increase, producing a denser matrix. However for LW1, microcracks were present on the surface, which reduced the compressive strength and increased water absorption and porosity.

  6. Improved design of support for large aperture space lightweight mirror (United States)

    Wang, Chao; Ruan, Ping; Liu, Qimin


    In order to design a kind of rational large aperture space mirror which can adapt to the space gravity and thermal environment, by taking the choice of material, the lightweight of the mirror and the design of support into account in detail, a double-deck structure with traditional flexible hinge was designed, then the analytical mathematical model of the mirror system was established. The design adopts six supports on back. in order to avoid the constraints, mirror is connected to three middle transition pieces through six flexible hinges, and then the three transition pieces are connected to support plate through another three flexible hinges. However, the initial structure is unable to reach the expected design target and needs to be made further adjustments. By improving and optimizing the original structure, a new type of flexible hinge in the shape of the letter A is designed finally. Compared with the traditional flexible hinge structure, the new structure is simpler and has less influence on the surface figure accuracy of mirror. By using the finite element analysis method, the static and dynamic characteristics as well as the thermal characteristics of the mirror system are analyzed. Analysis results show that the maximum PV value is 37 nm and the maximum RMS value is 10.4 nm when gravity load is applied. Furthermore, the maximum PV value is 46 nm and the maximum RMS value is 10.5 nm under the load case of gravity coupled with 4℃ uniform temperature rise. The results satisfy the index of optical design. The first order natural frequency of the mirror component is 130 Hz according to the conclusion obtained by modal analytical solution, so the mirror structure has high enough fundamental frequency. And, the structural strength can meet the demand under the overload and the random vibration environment respectively. It indicates that the mirror component structure has enough dynamic, static stiffness and thermal stability, meeting the design requirements.

  7. Exploratory Study of Palm Oil Fuel Ash as Partial Cement Replacement in Oil Palm Shell Lightweight Aggregate Concrete


    Muthusamy, K.; Z. Nur Azzimah


    In Malaysia, issue of environmental pollution resulting from disposal of Palm Oil Fuel Ash (POFA) which is a by-product from palm oil mill has initiated research to incorporate this waste in Oil Palm Shell (OPS) lightweight aggregate concrete production. The current study investigates the effect of palm oil fuel ash content as partial cement replacement towards compressive strength OPS lightweight aggregate concrete. Several OPS lightweight aggregate concrete mixes were produced by replacing ...

  8. Compactness in L-Fuzzy Topological Spaces

    CERN Document Server

    Luna-Torres, Joaquin


    We give a definition of compactness in L-fuzzy topological spaces and provide a characterization of compact L-fuzzy topological spaces, where L is a complete quasi-monoidal lattice with some additional structures, and we present a version of Tychonoff's theorem within the category of L-fuzzy topological spaces.

  9. The double explosive layer cylindrical compaction method

    NARCIS (Netherlands)

    Stuivinga, M.E.C.; Verbeek, H.J.; Carton, E.P.


    The standard cylindrical configuration for shock compaction is useful for the compaction of composite materials which have some plastic behavior. It can also be used to densify hard ceramics up to about 85% of the theoretical density (TMD), when low detonation velocity explosives (2-4 km s-1) are us

  10. Influence of compaction on chloride ingress

    NARCIS (Netherlands)

    Zlopasa, J.


    Experiences from practice show the need for more of an understanding and optimization of the compaction process in order to design a more durable concrete structure. Local variations in compaction are very often the reason for initiation of local damage and initiation of chloride induced corrosion.

  11. Feature Based Control of Compact Disc Players

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh

    Two servo control loops are used to keep the Optical Pick-up Unit focused and radially on the information track of the Compact Disc. These control servos have problems handling surface faults on the Compact Disc. In this Ph.D thesis a method is proposed to improve the handling of these surface...

  12. Interpolation of bilinear operators and compactness

    CERN Document Server

    da Silva, Eduardo Brandani


    The behavior of bilinear operators acting on interpolation of Banach spaces for the $\\rho$ method in relation to the compactness is analyzed. Similar results of Lions-Peetre, Hayakawa and Person's compactness theorems are obtained for the bilinear case and the $\\rho$ method.

  13. Compact Process Development at Babcock & Wilcox

    Energy Technology Data Exchange (ETDEWEB)

    Eric Shaber; Jeffrey Phillips


    Multiple process approaches have been used historically to manufacture cylindrical nuclear fuel compacts. Scale-up of fuel compacting was required for the Next Generation Nuclear Plant (NGNP) project to achieve an economically viable automated production process capable of providing a minimum of 10 compacts/minute with high production yields. In addition, the scale-up effort was required to achieve matrix density equivalent to baseline historical production processes, and allow compacting at fuel packing fractions up to 46% by volume. The scale-up approach of jet milling, fluid-bed overcoating, and hot-press compacting adopted in the U.S. Advanced Gas Reactor (AGR) Fuel Development Program involves significant paradigm shifts to capitalize on distinct advantages in simplicity, yield, and elimination of mixed waste. A series of compaction trials have been completed to optimize compaction conditions of time, temperature, and forming pressure using natural uranium oxycarbide (NUCO) fuel at packing fractions exceeding 46% by volume. Results from these trials are included. The scale-up effort is nearing completion with the process installed and operable using nuclear fuel materials. Final process testing is in progress to certify the process for manufacture of qualification test fuel compacts in 2012.


    Institute of Scientific and Technical Information of China (English)


    The compaction of pure Cu powder was carried out through a series of experiments using dynamic magnetic pulse compaction, and the effects of process parameters, such as discharge energy and compacting direction, on the homogeneity and the compaction density of compacted specimens were presented and discussed. The results indicated that the compaction density of specimens increased with the augment of discharge voltage and time. During unidirectional compaction, there was a density gradient along the loading direction in the compacted specimen, and the minimum compaction density was localized to the center of the bottom of the specimen. The larger the aspect ratio of a powder body, the higher the compaction density of the compacted specimen. And high conductivity drivers were beneficial to the increase of the compaction density. The iterative and the double direction compaction were efficient means to manufacture the homogeneous and high-density powder parts.

  15. Lightweight Ultrahigh Temperature CMC-Encased C/C Structure for Reentry and Hypersonic Applications, Phase II Project (United States)

    National Aeronautics and Space Administration — Future reentry and hypersonic vehicles require advanced lightweight leading edge thermal protection systems that can provide the dual functionality of...

  16. FSC赛车轻量化系统研究%Study on Lightweight System of FSC Race Car

    Institute of Scientific and Technical Information of China (English)

    彭仁杰; 阳林; 周永光; 冯勇; 贺绍华; 曾繁武


    提出针对FSC赛车轻量化研究的四种方法:材料轻量化、结构轻量化、制造轻量化和功能轻量化;介绍轻量化设计原则、功能轻量化方法、材料的强度属性和刚度属性、结构优化的方法、零部件的加工工艺和连接技术,并将这些方法应用于赛车设计的工程实际。实践结果表明,多种轻量化方法联合应用的减重效果比单个轻量化方法应用减重效果好。%The four ways research for FSC race lightweight are put forward in this paper, including materials lightweight, structural lightweight, manufacturing lightweight and functional lightweight. The authors introduce the principles of lightweight design, methods of functional lightweight, strength properties and stiffness properties of materials, methods of structural optimization, processing technology and connectivity technologies of parts, apply these methods to engineering practice of race car design. The practice shows that it is better to use the combination of a variety of lightweight methods than to use a single lightweight method.


    Institute of Scientific and Technical Information of China (English)


    A new class of finite difference schemes--the weighted compact schemes are proposed. According to the idea of the WENO schemes, the weighted compact scheme is constructed by a combination of the approximations of derivatives on candidate stencils with properly assigned weights so that the non-oscillatory property is achieved when discontinuities appear. The primitive function reconstruction method of ENO schemes is applied to obtain the conservative form of the weighted compact scheme. This new scheme not only preserves the characteristic of standard compact schemes and achieves high order accuracy and high resolution using a compact stencil,but also can accurately capture shock waves and discontinuities without oscillation, Numerical examples show that the new scheme is very promising and successful.``

  18. Reducing supply chain energy use in next-generation vehicle lightweighting

    Energy Technology Data Exchange (ETDEWEB)

    Hanes, Rebecca J.; Das, Sujit; Carpenter, Alberta


    Vehicle lightweighting reduces the amount of fuel consumed in a vehicle's use phase, but depending on what lightweight materials replace the conventional materials, and in what amounts, the manufacturing energy may increase or decrease. For carbon fiber reinforced polymer (CFRP), a next-generation lightweighting material, the increase in vehicle manufacturing energy is greater than the fuel savings, resulting in a net increase in energy consumption over a vehicle's manufacturing and use relative to a standard non-lightweighted car. [1] This work explores ways to reduce the supply chain energy of CFRP lightweighted vehicles through alternative production technologies and energy efficiency improvements. The objective is to determine if CFRP can offer energy savings comparable to or greater than aluminum, a conventional lightweighting material. Results of this analysis can be used to inform additional research and development efforts in CFRP production and future directions in lightweight vehicle production. The CFRP supply chain is modeled using the Material Flows through Industry (MFI) scenario modeling tool, which calculates 'mine to materials' energy consumption, material inventories and greenhouse gas emissions for industrial supply chains. In this analysis, the MFI tool is used to model the supply chains of two lightweighted vehicles, an aluminum intensive vehicle (AIV) and a carbon fiber intensive vehicle (CFV), under several manufacturing scenarios. Vehicle specifications are given in [1]. Scenarios investigated cover alternative carbon fiber (CF) feedstocks and energy efficiency improvements at various points in the vehicle supply chains. The alternative CF feedstocks are polyacrylonitrile, lignin and petroleum-derived mesophase pitch. Scenarios in which the energy efficiency of CF and CFRP production increases are explored using sector efficiency potential values, which quantify the reduction in energy consumption achievable when process

  19. Proliferation, angiogenesis and differentiation related markers in compact and follicular-compact thyroid carcinomas in dogs (United States)

    Pessina, P.; Castillo, V.A.; César, D.; Sartore, I.; Meikle, A.


    Immunohistochemical markers (IGF-1, IGF-1R, VEGF, FGF-2, RARα and RXR) were evaluated in healthy canine thyroid glands (n=8) and in follicular-compact (n=8) and compact thyroid carcinomas (n=8). IGF-1, IGF-1R and VEGF expression was higher in fibroblasts and endothelial cells of compact carcinoma than in healthy glands (P < 0.05). Compared to follicular-compact carcinoma, compact carcinoma had higher IGF-1R expression in fibroblasts, and higher FGF-2 expression in endothelial cells (P < 0.05). RARα expression was higher in endothelial cells of compact carcinoma than in those of other groups (P < 0.05). The upregulation of these proliferation- and angiogenesis-related factors in endothelial cells and/or fibroblasts and not in follicular cells of compact carcinoma compared to healthy glands supports the relevance of stromal cells in cancer progression. PMID:28116249

  20. Ultra Compact Imaging Spectrometer (UCIS) (United States)

    Blaney, Diana L.; Green, Robert; Mouroulis, Pantazis; Cable, Morgan; Ehlmann, Bethany; Haag, Justin; Lamborn, Andrew; McKinley, Ian; Rodriguez, Jose; van Gorp, Byron


    The Ultra Compact Imaging Spectrometer (UCIS) is a modular visible to short wavelength infrared imaging spectrometer architecture which could be adapted to a variety of mission concepts requiring low mass and low power. Imaging spectroscopy is an established technique to address complex questions of geologic evolution by mapping diagnostic absorption features due to minerals, organics, and volatiles throughout our solar system. At the core of UCIS is an Offner imaging spectrometer using M3 heritage and a miniature pulse tube cryo-cooler developed under the NASA Maturation of Instruments for Solar System Exploration (MatISSE) program to cool the focal plane array. The TRL 6 integrated spectrometer and cryo-cooler provide a basic imaging spectrometer capability that is used with a variety of fore optics to address lunar, mars, and small body science goals. Potential configurations include: remote sensing from small orbiters and flyby spacecraft; in situ panoramic imaging spectroscopy; and in situ micro-spectroscopy. A micro-spectroscopy front end is being developed using MatISSE funding with integration and testing planned this summer.

  1. Compact Nanowire Sensors Probe Microdroplets. (United States)

    Schütt, Julian; Ibarlucea, Bergoi; Illing, Rico; Zörgiebel, Felix; Pregl, Sebastian; Nozaki, Daijiro; Weber, Walter M; Mikolajick, Thomas; Baraban, Larysa; Cuniberti, Gianaurelio


    The conjunction of miniature nanosensors and droplet-based microfluidic systems conceptually opens a new route toward sensitive, optics-less analysis of biochemical processes with high throughput, where a single device can be employed for probing of thousands of independent reactors. Here we combine droplet microfluidics with the compact silicon nanowire based field effect transistor (SiNW FET) for in-flow electrical detection of aqueous droplets one by one. We chemically probe the content of numerous (∼10(4)) droplets as independent events and resolve the pH values and ionic strengths of the encapsulated solution, resulting in a change of the source-drain current ISD through the nanowires. Further, we discuss the specificities of emulsion sensing using ion sensitive FETs and study the effect of droplet sizes with respect to the sensor area, as well as its role on the ability to sense the interior of the aqueous reservoir. Finally, we demonstrate the capability of the novel droplets based nanowire platform for bioassay applications and carry out a glucose oxidase (GOx) enzymatic test for glucose detection, providing also the reference readout with an integrated parallel optical detector.

  2. A compact optical fiber positioner (United States)

    Hu, Hongzhuan; Wang, Jianping; Liu, Zhigang; Zhou, Zengxiang; Zhai, Chao; Chu, Jiaru


    In this paper, a compact optical fiber positioner is proposed, which is especially suitable for small scale and high density optical fiber positioning. Based on the positioning principle of double rotation, positioner's center shaft depends on planetary gear drive principle, meshing with the fixed annular gear central motor gear driving device to rotate, and the eccentric shaft rotated driving by a coaxial eccentric motor, both center and the eccentric shaft are supported by a rolling bearings; center and eccentric shaft are both designed with electrical zero as a reference point, and both of them have position-limiting capability to ensure the safety of fiber positioning; both eccentric and center shaft are designed to eliminating clearance with spring structure, and can eliminate the influence of gear gap; both eccentric and center motor and their driving circuit can be installed in the positioner's body, and a favorable heat sink have designed, the heat bring by positioning operation can be effectively transmit to design a focal plane unit through the aluminum component, on sleeve cooling spiral airway have designed, when positioning, the cooling air flow is inlet into install hole on the focal plate, the cooling air flow can effectively take away the positioning's heat, to eliminate the impact of the focus seeing. By measuring position device's sample results show that: the unit accuracy reached 0.01mm, can meet the needs of fiber positioning.

  3. A compact field fluorometer and its application to dye tracing in karst environments (United States)

    Poulain, Amaël; Rochez, Gaëtan; Van Roy, Jean-Pierre; Dewaide, Lorraine; Hallet, Vincent; De Sadelaer, Geert


    Dye tracing is a classic technique in hydrogeology to investigate surface-water or groundwater flow characteristics, and it is useful for many applications including natural or industrial issues. The Fluo-Green field fluorometer has been successfully tested in a karst environment and is specifically suitable for in-cave karst water monitoring. Karst research often uses dyes to obtain information about groundwater flow in unexplored cave passages. The compact device, alternatively named Fluo-G, meets the requirements of cave media: small (10 × 16 × 21 cm), lightweight (0.75 kg without ballast) and simple in conception. It is easy for cavers to set up and handle compared to other sampling methods. The fluorometer records uranine, turbidity and temperature with a user-defined time-step (1 min - 1 day). Very low energy consumption allows 9,000 measurements with six AA batteries. The device was calibrated and tested in the laboratory and in field conditions in Belgian karst systems. Results are in good fit with other sampling methods: in-situ fluorometers and automatic water sampling plus laboratory analysis. Recording high quality data (breakthrough curves) in karst with in-cave monitoring is valuable to improve knowledge of karst systems. Many hydrological and hydrogeological applications can benefit from such a low-cost and compact device, and finding the best compromise between resources and quality data is essential. Several improvements are possible but preliminary field tests are very promising.

  4. Concept of a nuclear powered submersible research vessel and a compact reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kusunoki, Tsuyoshi; Odano, Naoteru; Yoritsune, Tsutomu; Ishida, Toshihisa [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Takahashi, Teruo [Energis, Co., Kobe, Hyogo (Japan); Nishimura, Hajime [Japan Marine Science and Technology Center, Yokosuka, Kanagawa (Japan); Tokunaga, Sango [Japan Deep Sea Technology Association, Tokyo (Japan)


    A conceptual design study of a submersible research vessel navigating in 600 m depth and a compact nuclear reactor were carried out for the expansion of the nuclear power utilization. The mission of the vessel is the research of mechanism of the climate change to predict the global environment. Through conditions of the Arctic Ocean and the sea at high latitude have significant impacts on the global environmental change, it is difficult to investigate those areas by ordinary ships because of thick ice or storm. Therefore the research vessel is mainly utilized in the Arctic Ocean and the sea at high latitude. By taking account of the research mission, the basic specifications of the vessel are decided; the total weight is 500 t, the submersible depth is 600 m, the maximum speed is 12 knots (22.2 km/h), and the number of crews is 16. Nuclear power has an advantage in supplying large power of electricity in the sea for long period. Based on the requirements, it has been decided that two sets of submersible compact reactor, SCR, which is light-weighted and of enhanced safety characteristics of supply the total electricity of 500 kW. (author)

  5. Compact Extensible Authentication Protocol for the Internet of Things: Enabling Scalable and Efficient Security Commissioning

    Directory of Open Access Journals (Sweden)

    Marcin Piotr Pawlowski


    Full Text Available Internet of Things security is one of the most challenging parts of the domain. Combining strong cryptography and lifelong security with highly constrained devices under conditions of limited energy consumption and no maintenance time is extremely difficult task. This paper presents an approach that combines authentication and bootstrapping protocol (TEPANOM with Extensible Authentication Protocol (EAP framework optimized for the IEEE 802.15.4 networks. The solution achieves significant reduction of network resource usage. Additionally, by application of EAP header compacting approach, further network usage savings have been reached. The EAP-TEPANOM solution has achieved substantial reduction of 42% in the number of transferred packets and 35% reduction of the transferred data. By application of EAP header compaction, it has been possible to achieve up to 80% smaller EAP header. That comprises further reduction of transferred data for 3.84% for the EAP-TEPANOM method and 10% for the EAP-TLS-ECDSA based methods. The results have placed the EAP-TEPANOM method as one of the most lightweight EAP methods from ones that have been tested throughout this research, making it feasible for large scale deployments scenarios of IoT.

  6. Image overlay solution based on threshold detection for a compact near infrared fluorescence goggle system. (United States)

    Gao, Shengkui; Mondal, Suman B; Zhu, Nan; Liang, RongGuang; Achilefu, Samuel; Gruev, Viktor


    Near infrared (NIR) fluorescence imaging has shown great potential for various clinical procedures, including intraoperative image guidance. However, existing NIR fluorescence imaging systems either have a large footprint or are handheld, which limits their usage in intraoperative applications. We present a compact NIR fluorescence imaging system (NFIS) with an image overlay solution based on threshold detection, which can be easily integrated with a goggle display system for intraoperative guidance. The proposed NFIS achieves compactness, light weight, hands-free operation, high-precision superimposition, and a real-time frame rate. In addition, the miniature and ultra-lightweight light-emitting diode tracking pod is easy to incorporate with NIR fluorescence imaging. Based on experimental evaluation, the proposed NFIS solution has a lower detection limit of 25 nM of indocyanine green at 27 fps and realizes a highly precise image overlay of NIR and visible images of mice in vivo. The overlay error is limited within a 2-mm scale at a 65-cm working distance, which is highly reliable for clinical study and surgical use.

  7. Silicon nitride for lightweight stiff structures for optical instruments (United States)

    Berroth, Karl; Devilliers, Christophe; Luichtel, Georg


    Due to their very specific set of material properties, silicon nitride and silicon carbide have gained a lot of interest in the last 20 years. Moreover, many new approaches in technical equipment and processes were enabled with corresponding research and production activities. Also large efforts were made at FCT during the last years, to get able to supply even very large and complex shaped components made of sintered silicon carbide (SSiC) and of gas pressure sintered silicon nitride (GPSN) ceramics. This approach has opened new applications and markets for such ceramic materials. On the other side, designers and engineers are now allowed to think much more complex in designing of ceramic components. In this paper, a new rapid prototyping routine for very complex components as well as the corresponding materials will be presented. Components for optical equipment in innovative avionic and space applications, and more conventional technologies are described. Not only their unique key intrinsic properties, like high Youngs Modulus, very low CTE, very high strength and fracture toughness for a ceramic but also newly developed and adopted shaping, sintering and machining technologies in both green and sintered state have let to highly valued products. This enabled FCT to offer Carl Zeiss Optronics using silicon nitride for a newly designed, very complex housing structure of an avionic pod camera. Due to a very low CTE, high stiffness and less weight, an improved performance was reached. Also Thales Alenia Space is engaged since some years in activities to develop and qualify Silicon nitride ceramics for space projects. Extremely stiff, very lightweight and large truss space structures with a very low CTE, high rigidity and no outgasing for satellites can now be realized. Deep tests sequence has been performed to qualify truss beams and end fittings made in the same material. Also advanced dynamic testing equipment for avionic turbine blades requires new approaches. In

  8. Explosive compaction of CuCr alloys

    Institute of Scientific and Technical Information of China (English)

    李金平; 罗守靖; 龚朝晖; 牛玮; 纪松


    The production of CuCr alloys utilizing explosive compaction was studied. Mixture powders of CuCr alloys placed in tubes with a dimension of d14.0mm×21.4mm can be compacted using explosive pads of 16.5mm or 22.5mm. Thicker pads of explosive make the compacts more porous. The effects of the ratio of me/mp, ratio of me/(mp+mt) and impact energy on the density of compacts were similar, they were chosen to control explosive compaction, respectively. When adequate value of the parameters me/mp, me/(mt+mp) and impact energy of unit area of tube was chosen, high density(7.858g/cm3), high hardness(HB189) and low conductance (13.6MS/m) of CuCr alloys could be made by explosive compaction. The general properties of CuCr alloys by explosive compaction are similar to those of CuCr alloys by traditional process.

  9. Soil compaction and fertilization in soybean productivity

    Directory of Open Access Journals (Sweden)

    Beutler Amauri Nelson


    Full Text Available Soil compaction and fertilization affect soybean development. This study evaluated the effects of soil compaction and fertilization on soybean (Glycine max cv. Embrapa 48 productivity in a Typic Haplustox under field conditions in Jaboticabal, SP, Brazil. A completely randomized design with a 5 x 2 factorial layout (compaction vs. fertilization, with four replications in each treatment, was employed. Each experimental unit (replicate consisted of a 3.6 m² useful area. After the soil was prepared by cultivation, an 11 Mg tractor passed over it a variable number of times to create five levels of compaction. Treatments were: T0= no compaction, T1= one tractor pass, T2= two, T4= four, and T6= six passes, and no fertilizer and fertilizer to give soybean yields of 2.5 to 2.9 Mg ha-1. Soil was sampled at depths of 0.02-0.05, 0.07-0.10, and 0.15-0.18 m to determine macro and microporosity, penetration resistance (PR, and bulk density (Db. After 120 days growing under these conditions, the plants were analyzed in terms of development (plant height, number of pods, shoot dry matter per plant and weight of 100 seeds and seed productivity per hectare. Soil compaction decreased soybean development and productivity, but this effect was decreased by soil fertilization, showing that such fertilization increased soybean tolerance to soil compaction.

  10. Evaluation of automatic vacuum- assisted compaction solutions

    Directory of Open Access Journals (Sweden)

    M. Brzeziński


    Full Text Available Currently on the mould-making machines market the companies like: DiSA, KUENKEL WAGNER, HAFLINGER, HEINRICH WAGNER SINTO, HUNTER, SAVELLI AND TECHNICAL play significant role. These companies are the manufacturers of various solutions in machines and instalations applied in foundry engineering. Automatic foundry machines for compaction of green sand have the major role in mechanisation and automation processes of making the mould. The concept of operation of automatic machines is based on the static and dynamic methods of compacting the green sand. The method which gains the importance is the compacting method by using the energy of the air pressure. It's the initial stage or the supporting process of compacting the green sand. However in the automatic mould making machines using this method it's essential to use the additional compaction of the mass in order to receive the final parameters of the form. In the constructional solutions of the machines there is the additional division which concerns the method of putting the sand into the mould box. This division distinquishes the transport of the sand with simultaneous compaction or the putting of the sand without the pre-compaction. As the solutions of the major manufacturers are often the subject for application in various foundries, the authors of the paper would like/have the confidence to present their own evaluation process confirmed by their own researches and independent analysis of the producers' solutions.

  11. Experimental study on superposition theory of self compacting concrete filled steel tube%自密实薄壁钢管混凝土叠加理论试验研究

    Institute of Scientific and Technical Information of China (English)

    翟红侠; 杨光; 华磊


    By using different raw materials concrete strength ,apparent density and volume shrinkage are ad‐justed to configure ordinary self -compacting concrete (PT ) ,added expansive agent self -compacting con‐crete (EPT) ,self-compacting lightweight aggregate concrete (LC) and added expansive agent self -compac‐ting lightweight concrete (ELC) .Through experimental research and ANSYS finite element analysis ,the square steel concrete columns axial load model was built ,and the thin -walled square steel tube inner self compaction concrete with steel composite superimposed stress strain were also studied .%采用不同原材料调整混凝土强度、表观密度及体积稳定性,配制普通自密实混凝土(PT )、添加膨胀剂自密实混凝土(EPT )、自密实轻集料混凝土(LC )、添加膨胀剂自密实轻集料混凝土(ELC ),通过试验研究和采用ANSYS有限元分析,建立方形钢管混凝土轴心荷载模型,研究薄壁方形钢管自密实混凝土与钢管复合叠加应力应变规律。

  12. Self Compacting Concrete And Its Properties

    Directory of Open Access Journals (Sweden)

    S. Mahesh


    Full Text Available Self-compacting concrete (SCC, which flows under its own weight and doesn’t require any external vibration for compaction, has revolutionized concrete placement. Such concrete should have relatively low yield value to ensure high flow ability, a moderate viscosity to resists segregation and bleeding and must maintain its homogeneity during transportation, placing and curing to ensure adequate structural performance and long term durability. Self-compacting concrete (SCC can be defined as a fresh concrete which possesses superior flow ability under maintained stability (i.e. no segregation thus allowing self-compaction that is, material consolidation without addition of energy. Self-compacting concrete is a fluid mixture suitable for placing in structures with Congested reinforcement without vibration and it helps in achieving higher quality of surface finishes. However utilization of high reactive Metakaolin and Flyash asan admixtures as an effective pozzolan which causes great improvement in the porestructure. The relative proportions of key components are considered by volumerather than by mass. self compacting concrete (SCC mix design with 29% of coarse aggregate, replacement of cement with Metakaolin and class F flyash, combinations of both and controlled SCC mix with 0.36 water/cementitious ratio(by weight and388 litre/m3 of cement paste volume. Crushed granite stones of size 16mm and12.5mm are used with a blending 60:40 by percentage weight of total coarse aggregate. Self-compacting concrete compactibility is affected by the characteristics of materials and the mix proportions; it becomes necessary to evolve a procedure formix design of SCC. The properties of different constituent materials used in this investigation and its standard tests procedures for acceptance characteristics of self compacting concrete such as slump flow, V-funnel and L-Box are presented.

  13. Beetle forewings: Epitome of the optimal design for lightweight composite materials. (United States)

    Chen, Jinxiang; Wu, Gang


    Based on studies of the forewings of two beetles, Allomyrina dichotoma and Prosopocoilus inclinatus, this paper reviews and identifies the potential benefits of studying the structure of the beetle forewing and the associated development of lightweight biomimetic composite materials. The forewings of both beetle species consist of an integrated border frame structure and a large center part with distributed trabecular supports in the hollow core. The forewings of the male A. dichotoma are constructed to reflect a lightweight honeycomb design. However, the forewings of P. inclinatus are a durable structure. The biological significance of these structures is also discussed. This work proposes an integrated honeycomb structure inspired by the beetle forewing. A series of biological models are also proposed for lightweight integrated honeycomb structures and durable sandwich structures with a trabecular core, which are intended to establish a new direction in the development of biomimetic composite materials.

  14. Evaluation of Flanking Noise Transmission within Periodically Distributed Lightweight Beam Elements

    DEFF Research Database (Denmark)

    Domadiya, Parthkumar Gandalal; Andersen, Lars Vabbersgaard; Sorokin, Sergey


    Wooden frame structures are highly preferred as lightweight building systems nowadays. Lightweight building structures have gained more interest due to lower cost of production. However, there is a growing concern regarding noise and vibration issues within lightweight structures. Sound may pass...... from one room to another as indirect or flanking noise via joints or as direct transmission between adjacent rooms. The present analysis concerns flanking transmission within two-dimensional infinite periodic beam structures. The beam is comprised of two different materials placed in a periodic manner....... Two different theoretical methods are taken into consideration to evaluate flanking noise transmission within the beam structure: The finite-element method (FEM) and a Floquet theory approach. Research is carried out regarding the effects of periodicity in a wide range of frequencies from 0 to 300 Hz...

  15. Lightweight Investigation of Extended-Range Electric Vehicle Based on Collision Failure Using Numerical Simulation

    Directory of Open Access Journals (Sweden)

    Jiangqi Long


    Full Text Available The total weight of Extended-Range Electric Vehicle (E-REV is too heavy, which affects rear-end collision safety. Using numerical simulation, a lightweight method is designed to reduce E-REV body and key parts weight based on rear-end collision failure analysis. To calculate and optimize the performance of vehicle safety, the simulation model of E-REV rear-end collision safety is built by using finite element analysis. Drive battery pack lightweight design method is analyzed and the bending mode and torsional mode of E-REV before and after lightweight are compared to evaluate E-REV rear-end collision safety performance. The simulation results of optimized E-REV safety structure are verified by both numerical simulation and experimental investigation of the entire vehicle crash test.

  16. Advanced new lightweight materials: Hollow-sphere composites (HSCs) for mechanical engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Baumeister, E.; Klaeger, S. [Otto-von-Guerike-Universitaet, IFQ, Postfach 4120, D-39016 Magdeburg (Germany)


    ''Lightweight'' is a major trend in machine tool design to ensure higher speed and higher acceleration of elements, which results from state-of-the-art technology, such as the new linear drive and the control system.{sup [1]} Research is being carried out in institutes worldwide into lightweight construction by either design and/or choice of material. One type of advanced lightweight engineering material to reduce the mass of the moving parts of machine tools is hollow-sphere composites. Investigations of their thermal and mechanical properties show the superior quality of HSCs compared with alternative materials. Example applications of hollow-sphere composites include the table of a milling machine and robot arms. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  17. Model building with non-compact cosets (United States)

    Croon, Djuna Lize


    We explore Goldstone boson potentials in non-compact cosets of the form SO (n , 1) / SO (n). We employ a geometric approach to find the scalar potential, and focus on the conditions under which it is compact in the large field limit. We show that such a potential is found for a specific misalignment of the vacuum. This result has applications in different contexts, such as in Composite Higgs scenarios and theories for the Early Universe. We work out an example of inflation based on a non-compact coset which makes predictions which are consistent with the current observational data.

  18. Compact vs. Exponential-Size LP Relaxations

    Energy Technology Data Exchange (ETDEWEB)

    Carr, R.D.; Lancia, G.


    In this paper we introduce by means of examples a new technique for formulating compact (i.e. polynomial-size) LP relaxations in place of exponential-size models requiring separation algorithms. In the same vein as a celebrated theorem by Groetschel, Lovasz and Schrijver, we state the equivalence of compact separation and compact optimization. Among the examples used to illustrate our technique, we introduce a new formulation for the Traveling Salesman Problem, whose relaxation we show equivalent to the subtour elimination relaxation.

  19. The formation of compact groups of galaxies

    Institute of Scientific and Technical Information of China (English)

    马駬; 俞允强


    In the compact group of galaxies the galaxies can merge into a few massive ones in a very short time, so they must be formed very recently. On the other hand, according to the theory of structure formation, the denser system should form earlier. By analyzing the apparent paradox, we suggest that the merging process of CDM halo plays an important role in the formation of the compact groups of galaxies: it delays the formation of compact groups of galaxies, and makes the groups of galaxies much denser.

  20. Relativistic Solutions of Anisotropic Compact Objects

    CERN Document Server

    Paul, Bikash Chandra


    We present a class of new relativistic solutions with anisotropic fluid for compact stars in hydrostatic equilibrium. The interior space-time geometry considered here for compact objects are described by parameters namely, $\\lambda$, $k$, $A$, $R$ and $n$. The values of the geometrical parameters are determined here for obtaining a class of physically viable stellar models. The energy-density, radial pressure and tangential pressure are finite and positive inside the anisotropic stars. Considering some stars of known mass we present stellar models which describe compact astrophysical objects with nuclear density.