WorldWideScience

Sample records for self-healing software systems

  1. Self-Healing Laminate System

    Science.gov (United States)

    Beiermann, Brett A. (Inventor); Keller, Michael W. (Inventor); White, Scott R. (Inventor); Sottos, Nancy R. (Inventor)

    2016-01-01

    A laminate material may include a first flexible layer, and a self-healing composite layer in contact with the first flexible layer. The composite layer includes an elastomer matrix, a plurality of first capsules including a polymerizer, and a corresponding activator for the polymerizer. The laminate material may self-heal when subjected to a puncture or a tear.

  2. Self-healing systems and wireless networks management

    CERN Document Server

    Chaudhry, Junaid Ahsenali

    2013-01-01

    Do you believe in open-source development? Would you like to see your security system grow and learn by itself? Are you sick of paying for software license fees every year that produce little return on investment? And, would you prefer to invest in something you could sell later on to other IT security departments? If you answered yes to these questions, then this is the book for you.Addressing the issues of fault identification and classification, Self-Healing Systems and Wireless Networks Management presents a method for identifying and classifying faults using ca

  3. Novel routes to liquid-based self-healing polymer systems

    NARCIS (Netherlands)

    Mookhoek, S.D.

    2010-01-01

    Inspired by the current state-of-the-art and the progressing advancements in the field of self-healing materials, this thesis addresses several novel routes to advance the concept of liquid-based self-healing polymer systems. This thesis presents the concept and characterisation of a one-component

  4. Utilization of Self-Healing Materials in Thermal Protection System Applications

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project is the Utilization of Self-Healing Materials for Thermal Protection System (TPS) Applications. Currently, the technology for repairing TPS from...

  5. Self Healing Percolation

    Science.gov (United States)

    Scala, Antonio

    2015-03-01

    We introduce the concept of self-healing in the field of complex networks modelling; in particular, self-healing capabilities are implemented through distributed communication protocols that exploit redundant links to recover the connectivity of the system. Self-healing is a crucial in implementing the next generation of smart grids allowing to ensure a high quality of service to the users. We then map our self-healing procedure in a percolation problem and analyse the interplay between redundancies and topology in improving the resilience of networked infrastructures to multiple failures. We find exact results both for planar lattices and for random lattices, hinting the role of duality in the design of resilient networks. Finally, we introduce a cavity method approach to study the recovery of connectivity after damage in self-healing networks. CNR-PNR National Project ``Crisis-Lab,'' EU HOME/2013/CIPS/AG/4000005013 project CI2C and EU FET project MULTIPLEX nr.317532.

  6. Integration of the Reconfigurable Self-Healing eDNA Architecture in an Embedded System

    Science.gov (United States)

    Boesen, Michael Reibel; Keymeulen, Didier; Madsen, Jan; Lu, Thomas; Chao, Tien-Hsin

    2011-01-01

    In this work we describe the first real world case study for the self-healing eDNA (electronic DNA) architecture by implementing the control and data processing of a Fourier Transform Spectrometer (FTS) on an eDNA prototype. For this purpose the eDNA prototype has been ported from a Xilinx Virtex 5 FPGA to an embedded system consisting of a PowerPC and a Xilinx Virtex 5 FPGA. The FTS instrument features a novel liquid crystal waveguide, which consequently eliminates all moving parts from the instrument. The addition of the eDNA architecture to do the control and data processing has resulted in a highly fault-tolerant FTS instrument. The case study has shown that the early stage prototype of the autonomous self-healing eDNA architecture is expensive in terms of execution time.

  7. Thermosetting epoxy resin/thermoplastic system with combined shape memory and self-healing properties

    International Nuclear Information System (INIS)

    Yao, Yongtao; Wang, Jingjie; Lu, Haibao; Liu, Yanju; Leng, Jinsong; Xu, Ben; Fu, Yongqing

    2016-01-01

    A novel and facile strategy was proposed to construct a thermosetting/thermoplastic system with both shape memory and self-healing properties based on commercial epoxy resin and poly(ϵ-caprolactone)-PCL. Thermoplastic material is capable of re-structuring and changing the stiffness/modulus when the temperature is above melting temperature. PCL microfiber was used as a plasticizer in epoxy resin–based blends, and served as a ‘hard segment’ to fix a temporary shape of the composites during shape memory cycles. In this study, the electrospun PCL membrane with a porous network structure enabled a homogenous PCL fibrous distribution and optimized interaction between fiber and epoxy resin. The self-healing capability is achieved by phase transition during curing of the composites. The mechanism of the shape memory effect of the thermosetting (rubber)/thermoplastic composite is attributed to the structural design of the thermoplastic network inside the thermosetting resin/rubber matrix. (paper)

  8. Solid State Self-Healing System: Effects of Using Immiscible Healing Agents

    International Nuclear Information System (INIS)

    Noor Nabilah Muhamad; Mohd Suzeren Mohd Jamil

    2015-01-01

    The solid state self-healing system was obtained by employs a thermosetting epoxy resin, into which a thermoplastic is dissolved. The aim of this study is to identify the effect of using immiscible healing agents, which are polyvinyl chloride and polyvinyl alcohol, on solid state self-healing system. Healing was achieved by heating the fractured resins to a specific temperature; above their glass transition temperature (Tg) which obtained from dynamic mechanical analysis (DMA) in order for thermal expansion to occur. The thermal properties and bonding formed in the epoxy resins were characterized by means of Fourier Transform Infrared Spectroscopy (FTIR). Izod impact test was performed in preliminary work. Further work then has been done using compact tension test to demonstrate details self-healing capability of the different specimens. Under compact tension test, it was found that healable resin with PVC has highest healing efficiency followed PVA with 7.4 % and 3 % of average percentage healing efficiencies respectively. These results are due to the different solubility parameters of the thermoset/ network and thermoplastic polymer which led to the phase separation. Morphological studies using microscope optic prove the fracture-healing process and morphological properties of the resins. (author)

  9. Chelonia: A self-healing, replicated storage system

    International Nuclear Information System (INIS)

    Kerr Nilsen, Jon; Read, Alex; Toor, Salman; Nagy, Zsombor

    2011-01-01

    Chelonia is a novel grid storage system designed to fill the requirements gap between those of large, sophisticated scientific collaborations which have adopted the grid paradigm for their distributed storage needs, and of corporate business communities gravitating towards the cloud paradigm. Chelonia is an integrated system of heterogeneous, geographically dispersed storage sites which is easily and dynamically expandable and optimized for high availability and scalability. The architecture and implementation in term of web-services running inside the Advanced Resource Connector Hosting Environment Dameon (ARC HED) are described and results of tests in both local -area and wide-area networks that demonstrate the fault tolerance, stability and scalability of Chelonia will be presented. In addition, example setups for production deployments for small and medium-sized VO's are described.

  10. Chelonia: A self-healing, replicated storage system

    Science.gov (United States)

    Kerr Nilsen, Jon; Toor, Salman; Nagy, Zsombor; Read, Alex

    2011-12-01

    Chelonia is a novel grid storage system designed to fill the requirements gap between those of large, sophisticated scientific collaborations which have adopted the grid paradigm for their distributed storage needs, and of corporate business communities gravitating towards the cloud paradigm. Chelonia is an integrated system of heterogeneous, geographically dispersed storage sites which is easily and dynamically expandable and optimized for high availability and scalability. The architecture and implementation in term of web-services running inside the Advanced Resource Connector Hosting Environment Dameon (ARC HED) are described and results of tests in both local -area and wide-area networks that demonstrate the fault tolerance, stability and scalability of Chelonia will be presented. In addition, example setups for production deployments for small and medium-sized VO's are described.

  11. Thermally responsive polymer systems for self-healing, reversible adhesion and shape memory applications

    Science.gov (United States)

    Luo, Xiaofan

    Responsive polymers are "smart" materials that are capable of performing prescribed, dynamic functions under an applied stimulus. In this dissertation, we explore several novel design strategies to develop thermally responsive polymers and polymer composites for self-healing, reversible adhesion and shape memory applications. In the first case described in Chapters 2 and 3, a thermally triggered self-healing material was prepared by blending a high-temperature epoxy resin with a thermoplastic polymer, poly(epsilon-caprolactone) (PCL). The initially miscible system undergoes polymerization induced phase separation (PIPS) during the curing of epoxy and yields a variety of compositionally dependent morphologies. At a particular PCL loading, the cured blend displays a "bricks-and-mortar" morphology in which epoxy exists as interconnected spheres ("bricks") within a continuous PCL matrix ("mortar"). A heat induced "bleeding" phenomenon was observed in the form of spontaneous wetting of all free surfaces by the molten PCL, and is attributed to the volumetric thermal expansion of PCL above its melting point in excess of epoxy brick expansion, which we term differential expansive bleeding (DEB). This DEB is capable of healing damage such as cracks. In controlled self-healing experiments, heating of a cracked specimen led to PCL bleeding from the bulk that yields a liquid layer bridging the crack gap. Upon cooling, a "scar" composed of PCL crystals was formed at the site of the crack, restoring a significant portion of mechanical strength. We further utilized DEB to enable strong and thermally-reversible adhesion of the material to itself and to metallic substrates, without any requirement for macroscopic softening or flow. After that, Chapters 4--6 present a novel composite strategy for the design and fabrication of shape memory polymer composites. The basic approach involves physically combining two or more functional components into an interpenetrating fiber

  12. An immune-inspired swarm aggregation algorithm for self-healing swarm robotic systems.

    Science.gov (United States)

    Timmis, J; Ismail, A R; Bjerknes, J D; Winfield, A F T

    2016-08-01

    Swarm robotics is concerned with the decentralised coordination of multiple robots having only limited communication and interaction abilities. Although fault tolerance and robustness to individual robot failures have often been used to justify the use of swarm robotic systems, recent studies have shown that swarm robotic systems are susceptible to certain types of failure. In this paper we propose an approach to self-healing swarm robotic systems and take inspiration from the process of granuloma formation, a process of containment and repair found in the immune system. We use a case study of a swarm performing team work where previous works have demonstrated that partially failed robots have the most detrimental effect on overall swarm behaviour. We have developed an immune inspired approach that permits the recovery from certain failure modes during operation of the swarm, overcoming issues that effect swarm behaviour associated with partially failed robots. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. Self-Healing Wire Insulation

    Science.gov (United States)

    Parrish, Clyde F. (Inventor)

    2012-01-01

    A self-healing system for an insulation material initiates a self-repair process by rupturing a plurality of microcapsules disposed on the insulation material. When the plurality of microcapsules are ruptured, reactants within the plurality of microcapsules react to form a replacement polymer in a break of the insulation material. This self-healing system has the ability to repair multiple breaks in a length of insulation material without exhausting the repair properties of the material.

  14. Integration of the Reconfigurable Self-Healing eDNA Architecture in an Embedded System

    DEFF Research Database (Denmark)

    Boesen, Michael Reibel; Keymeulen, Didier; Madsen, Jan

    2011-01-01

    In this work we describe the first real world case study for the self-healing eDNA (electronic DNA) architecture by implementing the control and data processing of a Fourier Transform Spectrometer (FTS) on an eDNA prototype. For this purpose the eDNA prototype has been ported from a Xilinx Virtex 5...

  15. Interaction between microcapsules and cementitious matrix after cracking in a self-healing system

    NARCIS (Netherlands)

    Wang, X.; Xing, F.; Zhang, M.; Han, N.; Qian, Z.

    2013-01-01

    A new type of self-healing cementitious composites by using organic microcapsules is designed in Guangdong Key Laboratory of Durability for Coastal Civil Engineering, Shenzhen University. For the organic microcapsules, the shell material is urea formoldehyde (UF), and the core healing agent is

  16. Synthetic Self-Healing Methods

    Energy Technology Data Exchange (ETDEWEB)

    Bello, Mollie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-06-02

    Given enough time, pressure, temperature fluctuation, and stress any material will fail. Currently, synthesized materials make up a large part of our everyday lives, and are used in a number of important applications such as; space travel, under water devices, precise instrumentation, transportation, and infrastructure. Structural failure of these material scan lead to expensive and dangerous consequences. In an attempt to prolong the life spans of specific materials and reduce efforts put into repairing them, biologically inspired, self-healing systems have been extensively investigated. The current review explores recent advances in three methods of synthesized self-healing: capsule based, vascular, and intrinsic. Ideally, self-healing materials require no human intervention to promote healing, are capable of surviving all the steps of polymer processing, and heal the same location repeatedly. Only the vascular method holds up to all of these idealities.

  17. Fracture behaviour of a self-healing microcapsule-loaded epoxy system

    Directory of Open Access Journals (Sweden)

    2011-03-01

    Full Text Available The effect of temperature on the fracture behaviour of a microcapsule-loaded epoxy matrix was investigated. Microencapsulated epoxy and mercaptan-derivative healing agents were incorporated into an epoxy matrix to produce a polymer composite capable of self-healing. Maximum fracture loads were measured using the double-torsion method. Thermal aging at 55 and 110°C for 17 hours [hrs] was applied to heal the pre-cracked samples. The addition of microcapsules appeared to increase significantly the load carrying capacity of the epoxy after healing. Once healed, the composites achieved as much as 93–171% of its virgin maximum fracture load at 18, 55 and 110°C. The fracture behavior of the microcapsule- loaded epoxy matrix was influenced by the healing temperature. The high self-healing efficiency may be attributed to the result of the subsurface micro-crack pinning or deviation, and to a stronger microencapsulated epoxy and mercaptanderivative binder than that of the bulk epoxy. The results show that the healing temperature has a significant effect on recovery of load transferring capability after fracture.

  18. Setup of Extruded Cementitious Hollow Tubes as Containing/Releasing Devices in Self-Healing Systems

    Directory of Open Access Journals (Sweden)

    Alessandra Formia

    2015-04-01

    Full Text Available The aim of this research is to produce self-healing cementitious composites based on the use of cylindrical capsules containing a repairing agent. Cementitious hollow tubes (CHT having two different internal diameters (of 2 mm and 7.5 mm were produced by extrusion and used as containers and releasing devices for cement paste/mortar healing agents. Based on the results of preliminary mechanical tests, sodium silicate was selected as the healing agent. The morphological features of several mix designs used to manufacture the extruded hollow tubes, as well as the coatings applied to increase the durability of both core and shell materials are discussed. Three-point bending tests were performed on samples produced with the addition of the above-mentioned cementitious hollow tubes to verify the self-healing effectiveness of the proposed solution. Promising results were achieved, in particular when tubes with a bigger diameter were used. In this case, a substantial strength and stiffness recovery was observed, even in specimens presenting large cracks (>1 mm. The method is inexpensive and simple to scale up; however, further research is needed in view of a final optimization.

  19. Solid state self-healing system: Effects of using PDGEBA, PVC and PVA as linear healing agents

    Science.gov (United States)

    Muhamad, Noor Nabilah; Jamil, Mohd. Suzeren Md.; Abdullah, Shahrum

    2014-09-01

    The solid state self-healing system was obtained by employing a thermosetting epoxy resin, into which a thermoplastic is dissolved. In this study, the effect of healing efficiency was investigated by using different thermoplastic polymers which are poly(bisphenol-A-co-epichlorohydrin), polyvinyl chloride and polyvinyl alcohol as healing agents. Healing was achieved by heating the fractured resins to a specific temperature i.e. above their glass transition temperature (Tg) which obtained from dynamic mechanical analysis (DMA) to mobilize the polymeric chains of the healing agent. The curing reaction in the epoxy resins were characterized by means of Fourier transform infrared spectroscopy (FTIR). Izod impact test was been performed to demonstrate self-healing of the different specimens. Under test, it was found that healable resin with PDGEBA has highest healing efficiency followed by PVC and PVA, with 63%, 35% and 18% of average percentage healing efficiencies respectively. These results are due to the different solubility parameters of the thermoset/network and thermoplastic polymer which led to the phase separation. Morphological studies prove the fracture-healing process and morphological properties of the resins.

  20. Improvement of fatigue resistance of epoxy composite with microencapsulated epoxy-SbF5 self-healing system

    Directory of Open Access Journals (Sweden)

    X. J. Ye

    2017-11-01

    Full Text Available Rapid retardation and arresting of fatigue crack are successfully realized in the epoxy composite containing microencapsulated epoxy and ethanol solution of antimony pentafluoride-ethanol complex (SbF5·HOC2H5/HOC2H5. The effects of (i microcapsules induced-toughening, (ii hydrodynamic pressure crack tip shielding offered by the released healing agent, and (iii polymeric wedge and adhesive bonding of cured healing agent account for extension of fatigue life of the material. The two components of the healing agent can quickly react with each other soon after rupture of the microcapsules, and reconnect the crack only 20 seconds as of the test. The applied stress intensity range not only affects the healing efficiency, but also can be used to evaluate the healing speed. The present work offers a very fast healing system, and sets up a framework for characterizing speed of self-healing.

  1. Towards an understanding of thermally activated self-healing of an ionomer system during ballistic penetration

    International Nuclear Information System (INIS)

    Varley, Russell J.; Zwaag, Sybrand van der

    2008-01-01

    The self-healing phenomenon exhibited by the ionomer known as Surlyn 8940 (DuPont), a partially neutralized poly(ethylene-co-methacrylic acid) random co-polymer, during high-energy impact has been investigated here according to three separate strategies. The first consisted of a post-mortem scanning electron microscopy examination of impact surfaces of actual ballistic impacts for a range of bullets with different shapes, sizes and velocities. A complex range of competing and/or complementary processes based upon elastic and viscous responses was observed. The elastic response to impact provides for a polymer rebound or shape memory effect, while the viscous response provides for the final sealing of the cavity and is dependent upon the level of thermal frictional forces transferred during impact. The balance of these influences determines healing, and is shown to be altered by the size and shape of the bullet or indeed by the polymer morphology itself. The second strategy investigated the healing mechanism using a method that mimics the elastic response to impact in a controlled environment. This work highlighted the importance of the ionic clusters present in the ionomer and the gradient of viscoelastic properties formed at varying distances from the impact zone particularly when compared to non-ionic polymers. The repeatability of elastic healing was demonstrated, and reinforced the notion that healing arose from the inherent polymer structure of the ionomer. The third strategy investigated the role of the viscous response during impact and found that increased molecular mobility in the melt was critical to achieving optimal healing, although again the ionic clusters were found to be critical to maintaining sufficient structural integrity and preventing excess viscous flow

  2. Development of self-healing polymers via amine–epoxy chemistry: I. Properties of healing agent carriers and the modelling of a two-part self-healing system

    International Nuclear Information System (INIS)

    Zhang, He; Yang, Jinglei

    2014-01-01

    Two types of healing agent carriers (microcapsules containing epoxy solution, referred to as EP-capsules, and etched hollow glass bubbles (HGBs) loaded with amine solution, referred to as AM-HGBs) used in self-healing epoxy systems were prepared and characterized in this study. The core percentages were measured at about 80 wt% and 33 wt% for EP-capsules and AM-HGBs, respectively. The loaded amine in AM-HGB, after incorporation into the epoxy matrix, showed high stability at ambient temperature, but diffused out gradually during heat treatment at 80 °C. The amount and the mass ratio of the two released healants at the crack plane were correlated with the size, concentration, and core percentage of the healing agent carriers. A simplified cubic array model for randomly distributed healing agent carriers was adopted to depict the longest diffusion distance of the released healants, which is inversely proportional to the cubic root of the carrier concentration. (papers)

  3. Self-healing polymers

    Science.gov (United States)

    Klein, Daniel J. (Inventor)

    2011-01-01

    A three dimensional structure fabricated from a self-healing polymeric material, comprising poly(ester amides) obtained from ethylene glycol, azelaic acid and 1,1-aminoundecanoic acid, wherein polymeric material has a melt index above 2.5 g/10 min. as determined by ASTM D1238 at 190.degree. C. and 2.16kg, impact resistance and ductility sufficient to resist cracking and brittle fracture upon impact by a 9 mm bullet fired at a temperature of about 29.degree. C. at subsonic speed in a range from about 800 feet/sec to about 1000 feet/sec. It has been determined that the important factors necessary for self-healing behavior of polymers include sufficient impact strength, control of the degree of crystallinity, low melting point and the ability to instantly melt at impacted area.

  4. Possibility of self-healing by using capsules and vascular system to provide water in cementitious materials

    NARCIS (Netherlands)

    Huang, H.; Ye, G.

    2013-01-01

    Since self-healing of cracks is able to improve the durability of concrete structures, it has attracted much attention in the recent years. As known, in concrete matrix there are large amounts of cement grains remaining unhydrated, particularly in high performance concrete. Further hydration of

  5. Self-Healing Networks: Redundancy and Structure

    Science.gov (United States)

    Quattrociocchi, Walter; Caldarelli, Guido; Scala, Antonio

    2014-01-01

    We introduce the concept of self-healing in the field of complex networks modelling; in particular, self-healing capabilities are implemented through distributed communication protocols that exploit redundant links to recover the connectivity of the system. We then analyze the effect of the level of redundancy on the resilience to multiple failures; in particular, we measure the fraction of nodes still served for increasing levels of network damages. Finally, we study the effects of redundancy under different connectivity patterns—from planar grids, to small-world, up to scale-free networks—on healing performances. Small-world topologies show that introducing some long-range connections in planar grids greatly enhances the resilience to multiple failures with performances comparable to the case of the most resilient (and least realistic) scale-free structures. Obvious applications of self-healing are in the important field of infrastructural networks like gas, power, water, oil distribution systems. PMID:24533065

  6. A Fuzzy-Multiagent Self-Healing Scheme for a Distribution System with Distributed Generations

    DEFF Research Database (Denmark)

    Elmitwally, Akram; Elsaid, Mohammed; Elgamal, Mohammed

    2015-01-01

    In this paper, a new multi-agent control system (MACS) is proposed for smart distribution networks. It can: 1) eliminate the feeders' congestion, 2) globally correct voltage violations, and 3) coordinate the operation of reactive power control devices. In performing its functions, the MACS must...

  7. Design and Analysis of Self-Healing Tree-Based Hybrid Spectral Amplitude Coding OCDMA System

    Directory of Open Access Journals (Sweden)

    Waqas A. Imtiaz

    2017-01-01

    Full Text Available This paper presents an efficient tree-based hybrid spectral amplitude coding optical code division multiple access (SAC-OCDMA system that is able to provide high capacity transmission along with fault detection and restoration throughout the passive optical network (PON. Enhanced multidiagonal (EMD code is adapted to elevate system’s performance, which negates multiple access interference and associated phase induced intensity noise through efficient two-matrix structure. Moreover, system connection availability is enhanced through an efficient protection architecture with tree and star-ring topology at the feeder and distribution level, respectively. The proposed hybrid architecture aims to provide seamless transmission of information at minimum cost. Mathematical model based on Gaussian approximation is developed to analyze performance of the proposed setup, followed by simulation analysis for validation. It is observed that the proposed system supports 64 subscribers, operating at the data rates of 2.5 Gbps and above. Moreover, survivability and cost analysis in comparison with existing schemes show that the proposed tree-based hybrid SAC-OCDMA system provides the required redundancy at minimum cost of infrastructure and operation.

  8. Numerical modelling of self healing mechanisms

    NARCIS (Netherlands)

    Remmers, J.J.C.; Borst, de R.; Zwaag, van der S.

    2007-01-01

    A number of self healing mechanisms for composite materials have been presented in the previous chapters of this book. These methods vary from the classical concept of micro-encapsulating of healing agents in polymer systems to the autonomous healing of concrete. The key feature of these self

  9. Evaluation of long-term corrosion durability and self-healing ability of scratched coating systems on carbon steel in a marine environment

    Science.gov (United States)

    Zhao, Xia; Chen, Changwei; Xu, Weichen; Zhu, Qingjun; Ge, Chengyue; Hou, Baorong

    2017-09-01

    Defects in protective-coating systems on steel surfaces are inevitable in practical engineering applications. A composite coating system, including a primer, middle coat and topcoat, were used to protect carbon steel from corrosion in a marine environment. Two environmental additives, glass fibers and thiourea, were applied in the middle coat to modify the coating system. The long-term corrosion durability and self-healing ability of the scratched coating system were evaluated by multiple methods. Results of the electrochemical technologies indicated that the coating system that contained 0.5 wt.% fibers and 0.5 wt.% thiourea presented good corrosion protection and self-healing for carbon steel when immersed in 3.5% NaCl for 120 d. Evolution of localized corrosion factors with time, as obtained from the current distribution showed that fibers combined with thiourea could inhibit the occurrence of local corrosion in scratched coating systems and retarded the corrosion development significantly. Surface characterization suggested that adequate thiourea could be absorbed uniformly on fibers for a long time to play an important role in protecting the carbon steel. Finally, schematic models were established to demonstrate the action of fibers and thiourea on the exposed surface of the carbon steel and the scratched coating system in the entire deterioration process.

  10. Self-Healing, Inflatable, Rigidizable Shelter

    Science.gov (United States)

    Haight, Andrea; Gosau, Jan-Michael; Dixit, Anshu; Gleeson, Dan

    2012-01-01

    An inflatable, rigidizable shelter system was developed based on Rigi dization on Command (ROC) technology incorporating not only the requ ired low-stowage volume and lightweight character achieved from an i nflatable/rigidizable system, but also a self-healing foam system inc orporated between the rigidizable layers of the final structure to m inimize the damage caused by any punctures to the structure.

  11. Ballistic Puncture Self-Healing Polymeric Materials

    Science.gov (United States)

    Gordon, Keith L.; Siochi, Emilie J.; Yost, William T.; Bogert, Phil B.; Howell, Patricia A.; Cramer, K. Elliott; Burke, Eric R.

    2017-01-01

    Space exploration launch costs on the order of $10,000 per pound provide an incentive to seek ways to reduce structural mass while maintaining structural function to assure safety and reliability. Damage-tolerant structural systems provide a route to avoiding weight penalty while enhancing vehicle safety and reliability. Self-healing polymers capable of spontaneous puncture repair show promise to mitigate potentially catastrophic damage from events such as micrometeoroid penetration. Effective self-repair requires these materials to quickly heal following projectile penetration while retaining some structural function during the healing processes. Although there are materials known to possess this capability, they are typically not considered for structural applications. Current efforts use inexpensive experimental methods to inflict damage, after which analytical procedures are identified to verify that function is restored. Two candidate self-healing polymer materials for structural engineering systems are used to test these experimental methods.

  12. Self-Healing Structural Materials for Damage Tolerant Aerospace Vehicles

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed  effort describes how to develop novel lightweight, self-healing systems where self-repair is induced by the forces imparted by the damage event itself....

  13. Self Healing Coating/Film Project

    Science.gov (United States)

    Summerfield, Burton; Thompson, Karen; Zeitlin, Nancy; Mullenix, Pamela; Calle, Luz; Williams, Martha

    2015-01-01

    Kennedy Space Center (KSC) has been developing self healing materials and technologies. This project seeks to further develop self healing functionality in thin films for applications such as corrosion protective coatings, inflatable structures, space suit materials, and electrical wire insulation.

  14. Evaluating Self Healing Capability of Bituminous Mastics

    NARCIS (Netherlands)

    Qiu, J.; Van de Ven, M.; Wu, S.; Yu, J.; Molenaar, A.

    2012-01-01

    The self-healing capability of bituminous materials has been known for many years. Researches were mostly focused on the self healing behaviour during load repetitions. The tests are either time consuming and/or complex. In this paper, a simple self healing test procedure is presented combining the

  15. ‘Containers’ for self-healing epoxy composites and coating: Trends and advances

    Directory of Open Access Journals (Sweden)

    P. Vijayan

    2016-06-01

    Full Text Available The introduction of self-healing functionality into epoxy matrix is an important and challenging topic. Various micro/nano containers loaded self-healing agents are developed and incorporated into epoxy matrix to impart self-healing ability. The current report reviews the major findings in the area of self-healing epoxy composites and coatings with special emphasis on these containers. The preparation and use of polymer micro/nano capsules, polymer fibers, hollow glass fibers/bubbles, inorganic nanotubes, inorganic meso- and nano-porous materials, carbon nanotubes etc. as self-healing containers are outlined. The nature of the container and its response to the external stimulations greatly influence the self-healing performance. The self-healing mechanism associated with each type of container and the role of container parameters on self-healing performance of self-healing epoxy systems are reviewed. Comparison of the efficiency offered by different types of containers is introduced. Finally, the selection of containers to develop cost effective and green self-healing systems are mentioned.

  16. Developing Flexible, High Performance Polymers with Self-Healing Capabilities

    Science.gov (United States)

    Jolley, Scott T.; Williams, Martha K.; Gibson, Tracy L.; Caraccio, Anne J.

    2011-01-01

    Flexible, high performance polymers such as polyimides are often employed in aerospace applications. They typically find uses in areas where improved physical characteristics such as fire resistance, long term thermal stability, and solvent resistance are required. It is anticipated that such polymers could find uses in future long duration exploration missions as well. Their use would be even more advantageous if self-healing capability or mechanisms could be incorporated into these polymers. Such innovative approaches are currently being studied at the NASA Kennedy Space Center for use in high performance wiring systems or inflatable and habitation structures. Self-healing or self-sealing capability would significantly reduce maintenance requirements, and increase the safety and reliability performance of the systems into which these polymers would be incorporated. Many unique challenges need to be overcome in order to incorporate a self-healing mechanism into flexible, high performance polymers. Significant research into the incorporation of a self-healing mechanism into structural composites has been carried out over the past decade by a number of groups, notable among them being the University of I1linois [I]. Various mechanisms for the introduction of self-healing have been investigated. Examples of these are: 1) Microcapsule-based healant delivery. 2) Vascular network delivery. 3) Damage induced triggering of latent substrate properties. Successful self-healing has been demonstrated in structural epoxy systems with almost complete reestablishment of composite strength being achieved through the use of microcapsulation technology. However, the incorporation of a self-healing mechanism into a system in which the material is flexible, or a thin film, is much more challenging. In the case of using microencapsulation, healant core content must be small enough to reside in films less than 0.1 millimeters thick, and must overcome significant capillary and surface

  17. Puncture Self-Healing Polymers for Aerospace Applications

    Science.gov (United States)

    Gordon, Keith L.; Penner, Ronald K.; Bogert, Phil B.; Yost, W. T.; Siochi, Emilie J.

    2011-01-01

    Space exploration launch costs on the order of $10K per pound provide ample incentive to seek innovative, cost-effective ways to reduce structural mass without sacrificing safety and reliability. Damage-tolerant structural systems can provide a route to avoiding weight penalty while enhancing vehicle safety and reliability. Self-healing polymers capable of spontaneous puncture repair show great promise to mitigate potentially catastrophic damage from events such as micrometeoroid penetration. Effective self-repair requires these materials to heal instantaneously following projectile penetration while retaining structural integrity. Poly(ethylene-co-methacrylic acid) (EMMA), also known as Surlyn is an ionomer-based copolymer that undergoes puncture reversal (self-healing) following high impact puncture at high velocities. However EMMA is not a structural engineering polymer, and will not meet the demands of aerospace applications requiring self-healing engineering materials. Current efforts to identify candidate self-healing polymer materials for structural engineering systems are reported. Rheology, high speed thermography, and high speed video for self-healing semi-crystalline and amorphous polymers will be reported.

  18. Enzymetically regulating the self-healing of protein hydrogels with high healing efficiency.

    Science.gov (United States)

    Gao, Yuzhou; Luo, Quan; Qiao, Shanpeng; Wang, Liang; Dong, Zeyuan; Xu, Jiayun; Liu, Junqiu

    2014-08-25

    Enzyme-mediated self-healing of dynamic covalent bond-driven protein hydrogels was realized by the synergy of two enzymes, glucose oxidase (GOX) and catalase (CAT). The reversible covalent attachment of glutaraldehyde to lysine residues of GOX, CAT, and bovine serum albumin (BSA) led to the formation and functionalization of the self-healing protein hydrogel system. The enzyme-mediated protein hydrogels exhibit excellent self-healing properties with 100% recovery. The self-healing process was reversible and effective with an external glucose stimulus at room temperature. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Impact of self-healing capability on network robustness

    Science.gov (United States)

    Shang, Yilun

    2015-04-01

    A wide spectrum of real-life systems ranging from neurons to botnets display spontaneous recovery ability. Using the generating function formalism applied to static uncorrelated random networks with arbitrary degree distributions, the microscopic mechanism underlying the depreciation-recovery process is characterized and the effect of varying self-healing capability on network robustness is revealed. It is found that the self-healing capability of nodes has a profound impact on the phase transition in the emergence of percolating clusters, and that salient difference exists in upholding network integrity under random failures and intentional attacks. The results provide a theoretical framework for quantitatively understanding the self-healing phenomenon in varied complex systems.

  20. Microencapsulation of self-healing agents containing a fluorescent dye

    Directory of Open Access Journals (Sweden)

    J. K. Lee

    2013-01-01

    Full Text Available Two different self-healing agent candidates, endo-dicyclopentadiene (endo-DCPD and 5-ethylidene-2-norbornene (ENB, containing a fluorescent dye surrounded by a melamine–urea–formaldehyde (MUF shell were microencapsulated by in-situ polymerization and the resulting microcapsules were characterized in this work. The microcapsules showed a narrow size distribution with a spherical shape and rough outer and smooth inner surfaces for both healing agent systems. Shell thicknesses of the microcapsules were ~880±80 nm for endo-DCPD and ~620±60 nm for ENB. The incorporation of a fluorescent dye as tracer into self-healing agents did not disturb the formation of microcapsules. The release of self-healing liquid into the induced crack from ruptured microcapsules in an epoxy coating layer was observed using a fluorescence microscopy. The use of a fluorescent dye is very effective in the observation of a damage site.

  1. Dessign and Implementation of Hardened Reconfiguration Controller for Self-Healing Systems on SRAM-Based FPGAs

    OpenAIRE

    DERAKHSHAN, NASER

    2013-01-01

    As digital systems become large and complex, their dependability is getting more important, particularly in mission-critical and safety‐critical applications. Among various available platforms for implementing a digital system, SRAM-based Field Programmable Gate Arrays (FPGAs) are increasingly adopted in embedded systems due to their flexibility in achieving multiple requirements such as low cost, high performance, and fast turnaround time compared to Fixed Application Specific Integrated Cir...

  2. Self-healing of polymer modified concrete

    Directory of Open Access Journals (Sweden)

    Abd_Elmoaty M. Abd_Elmoaty

    2011-06-01

    Full Text Available Self healing phenomenon of concrete has been observed in traditional, fibrous, self compacting concrete. This phenomenon occurred mainly due to the presence of unhydrated cement particles in the presence of water. Mechanism of polymer in concrete depends on creating a layer and net of polymer around cement particles which enhances the properties of polymer modified concrete. This mechanism may affect the self healing of this type of concrete. This work aims to study the presence of the self healing phenomenon in polymer modified concrete and the related parameters. An experimental investigation on self healing of polymer modified concrete was undertaken. In this research work, effect of polymer type, polymer dose, cement content, cement type, w/cm ratio and age of damage were studied. The healing process extended up to 60 days. Ultrasonic pulse velocity measurements were used to evaluate the healing process. Results indicated that, the self healing phenomenon existed in polymer modified concrete as in traditional concrete. The increase of polymer dose increases the healing degree at the same healing time. This increase depends on polymer type. Also, the decrease of w/cm ratio reduces the self healing degree while the use of Type V Portland cement improves the self healing process compared with Type I Portland cement. Cement content has an insignificant effect on healing process for both concrete with and without polymer. In addition, the increase of damage age decreases the efficiency of self healing process.

  3. Self-healing composites and applications thereof

    Science.gov (United States)

    Tee, Chee Keong; Wang, Chao; Cui, Yi; Bao, Zhenan

    2016-11-08

    A battery electrode includes an electrochemically active material and a binder covering the electrochemically active material. The binder includes a self-healing polymer and conductive additives dispersed in the self-healing polymer to provide an electrical pathway across at least a portion of the binder.

  4. Self-healing cable for extreme environments

    Science.gov (United States)

    Huston, Dryver R. (Inventor); Tolmie, Bernard R. (Inventor)

    2009-01-01

    Self-healing cable apparatus and methods disclosed. The self-healing cable has a central core surrounded by an adaptive cover that can extend over the entire length of the self-healing cable or just one or more portions of the self-healing cable. The adaptive cover includes an axially and/or radially compressible-expandable (C/E) foam layer that maintains its properties over a wide range of environmental conditions. A tape layer surrounds the C/E layer and is applied so that it surrounds and axially and/or radially compresses the C/E layer. When the self-healing cable is subjected to a damaging force that causes a breach in the outer jacket and the tape layer, the corresponding localized axially and/or radially compressed portion of the C/E foam layer expands into the breach to form a corresponding localized self-healed region. The self-healing cable is manufacturable with present-day commercial self-healing cable manufacturing tools.

  5. Microencapsulation of Self Healing Agents for Corrosion Control Coatings

    Science.gov (United States)

    Jolley, S. T.; Li, W.; Buhrow, J. W.; Calle, L. M.

    2011-01-01

    Corrosion, the environmentally induced degradation of materials, is a very costly problem that has a major impact on the global economy. Results from a 2-year breakthrough study released in 2002 by the U.S. Federal Highway Administration (FHWA) showed that the total annual estimated direct cost associated with metallic corrosion in nearly every U.S. industry sector was a staggering $276 billion, approximately 3.1% of the nation's Gross Domestic Product (GOP). Corrosion protective coatings are widely used to protect metallic structures from the detrimental effects of corrosion but their effectiveness can be seriously compromised by mechanical damage, such as a scratch, that exposes the metallic substrate. The incorporation of a self healing mechanism into a corrosion control coating would have the potential to significantly increase its effectiveness and useful lifetime. This paper describes work performed to incorporate a number of microcapsule-based self healing systems into corrosion control coatings. The work includes the preparation and evaluation of self-healing systems based on curable epoxy, acrylate, and siloxane resins, as well as, microencapsulated systems based on passive, solvent born, healing agent delivery. The synthesis and optimization of microcapsule-based self healing systems for thin coating (less than 100 micron) will be presented.

  6. Self-healing elastomer system

    Science.gov (United States)

    Keller, Michael W. (Inventor); Sottos, Nancy R. (Inventor); White, Scott R. (Inventor)

    2009-01-01

    A composite material includes an elastomer matrix, a set of first capsules containing a polymerizer, and a set of second capsules containing a corresponding activator for the polymerizer. The polymerizer may be a polymerizer for an elastomer. The composite material may be prepared by combining a first set of capsules containing a polymerizer, a second set of capsules containing a corresponding activator for the polymerizer, and a matrix precursor, and then solidifying the matrix precursor to form an elastomeric matrix.

  7. Self-healing sandwich structures incorporating an interfacial layer with vascular network

    International Nuclear Information System (INIS)

    Chen, Chunlin; Peters, Kara; Li, Yulong

    2013-01-01

    A self-healing capability specifically targeted for sandwich composite laminates based on interfacial layers with built-in vascular networks is presented. The self-healing occurs at the facesheet–core interface through an additional interfacial layer to seal facesheet cracks and rebond facesheet–core regions. The efficacy of introducing the self-healing system at the facesheet–core interface is evaluated through four-point bend and edgewise compression testing of representative foam core sandwich composite specimens with impact induced damage. The self-healing interfacial layer partially restored the specific initial stiffness, doubling the residual initial stiffness as compared to the control specimen after the impact event. The restoration of the ultimate specific skin strength was less successful. The results also highlight the critical challenge in self-healing of sandwich composites, which is to rebond facesheets which have separated from the core material. (paper)

  8. Self-Healing Nanocomposites for Reusable Composite Cryotanks

    Science.gov (United States)

    Eberly, Daniel; Ou, Runqing; Karcz, Adam; Skandan, Ganesh

    2013-01-01

    nanoparticle additives. Unique nanoparticles were used that have been surface-functionalized to be compatible with the resin. Both organic and inorganic components toughen the matrix and result in a more impact-resistant COPV. In one resin system containing an inorganic nanomaterial additive, a significant improvement in burst performance was observed after the COPV was cryo-impact-damaged and then self-healed, with a greater than 10% improvement in burst pressure after the self-healing process was performed. Initial cross-sectional analysis via microscopy showed good resin infiltration of the carbon fibers and without voids. To further enhance the capability between the nanomaterial additives and the resin, a surface modification was successfully performed. A second specialty epoxy resin was prepared using a surface modified nanomaterial additive, and COPVs were fabricated. Steps were taken to improve the mechanical properties of the COPVs by using a low-viscosity resin system that contained a different curing agent. This lower viscosity improves the processing of the COPV, and preliminary results show that the burst pressure of these new vessels is 20 to 25% higher than that of the original. The self-healing concept demonstrated in this research and development effort represents a platform technology, and the self-healing property is neither restricted to the particular epoxy system used here, nor to the COPV application. Self-healing is a direct result of a unique phase separated morphology created via the resin and is aided by the nanoparticles. The self-healing function can be introduced to other customer-specific resin systems in coating, bulk, or composite applications provided that the unique phase separated morphology can be enabled in those systems.

  9. A comprehensive review on self-healing of asphalt materials: Mechanism, model, characterization and enhancement.

    Science.gov (United States)

    Sun, Daquan; Sun, Guoqiang; Zhu, Xingyi; Guarin, Alvaro; Li, Bin; Dai, Ziwei; Ling, Jianming

    2018-05-09

    Self-healing has great potential to extend the service life of asphalt pavement, and this capability has been regarded as an important strategy when designing a sustainable infrastructure. This review presents a comprehensive summary of the state-of-the-art investigations concerning the self-healing mechanism, model, characterization and enhancement, ranging from asphalt to asphalt pavement. Firstly, the self-healing phenomenon as a general concept in asphalt materials is analyzed including its definition and the differences among self-healing and some viscoelastic responses. Additionally, the development of self-healing in asphalt pavement design is introduced. Next, four kinds of possible self-healing mechanism and corresponding models are presented. It is pointed out that the continuum thermodynamic model, considering the whole process from damage initiation to healing recovery, can be a promising study field. Further, a set of self-healing multiscale characterization methods from microscale to macroscale as well as computational simulation scale, are summed up. Thereinto, the computational simulation shows great potential in simulating the self-healing behavior of asphalt materials from mechanical and molecular level. Moreover, the factors influencing self-healing capability are discussed, but the action mechanisms of some factors remain unclear and need to be investigated. Finally, two extrinsic self-healing technologies, induction heating and capsule healing, are recommended as preventive maintenance applications in asphalt pavement. In future, more effective energy-based healing systems or novel material-based healing systems are expected to be developed towards designing sustainable long-life asphalt pavement. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Recent Advancements in Self-Healing Metallic Materials and Self-Healing Metal Matrix Composites

    Science.gov (United States)

    Kilicli, Volkan; Yan, Xiaojun; Salowitz, Nathan; Rohatgi, Pradeep K.

    2018-04-01

    Engineered self-healing materials inspired by natural biological organisms that can repair damage are receiving increasing interest in recent years. Most studies have been focused on self-healing polymers, concretes, and ceramics. Self-healing metallic materials pose challenges due to the high temperatures used in manufacturing and the chemistries involved. This article summarizes and evaluates the self-healing mechanisms used in metallic materials and reviews recent studies into self-healing in aluminum, zinc, and Sn-Bi alloys. Generalizations about the various classifications are drawn from the review highlighting major hurdles in the widespread practical application of metallic self-healing materials, as well as the potential directions for future studies.

  11. The microstructure of capsule containing self-healing materials: A micro-computed tomography study

    Energy Technology Data Exchange (ETDEWEB)

    Van Stappen, Jeroen, E-mail: Jeroen.Vanstappen@ugent.be [UGCT/PProGRess, Dept. of Geology, Ghent University, Krijgslaan 281 S8, B-9000 Ghent (Belgium); SIM vzw, Technologiepark 935, B-9052 Zwijnaarde (Belgium); Bultreys, Tom [UGCT/PProGRess, Dept. of Geology, Ghent University, Krijgslaan 281 S8, B-9000 Ghent (Belgium); Gilabert, Francisco A. [Mechanics of Materials and Structures, Dept. of Materials Science and Engineering, Ghent University, Technologiepark Zwijnaarde 903, B-9052 Zwijnaarde (Belgium); SIM vzw, Technologiepark 935, B-9052 Zwijnaarde (Belgium); Hillewaere, Xander K.D. [Polymer Chemistry Research Group, Dept. of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281 S4-bis, B-9000 Ghent (Belgium); SIM vzw, Technologiepark 935, B-9052 Zwijnaarde (Belgium); Gómez, David Garoz [Mechanics of Materials and Structures, Dept. of Materials Science and Engineering, Ghent University, Technologiepark Zwijnaarde 903, B-9052 Zwijnaarde (Belgium); SIM vzw, Technologiepark 935, B-9052 Zwijnaarde (Belgium); Van Tittelboom, Kim [Magnel Laboratory for Concrete Research, Dept. of Structural Engineering, Ghent University, Technologiepark Zwijnaarde 904, B-9052 Ghent (Belgium); Dhaene, Jelle [UGCT/Radiation Physics, Dept. of Physics and Astronomy, Ghent University, Proeftuinstraat 86, B-9000 Ghent (Belgium); De Belie, Nele [Magnel Laboratory for Concrete Research, Dept. of Structural Engineering, Ghent University, Technologiepark Zwijnaarde 904, B-9052 Ghent (Belgium); Van Paepegem, Wim [Mechanics of Materials and Structures, Dept. of Materials Science and Engineering, Ghent University, Technologiepark Zwijnaarde 903, B-9052 Zwijnaarde (Belgium); Du Prez, Filip E. [Polymer Chemistry Research Group, Dept. of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281 S4-bis, B-9000 Ghent (Belgium); Cnudde, Veerle [UGCT/PProGRess, Dept. of Geology, Ghent University, Krijgslaan 281 S8, B-9000 Ghent (Belgium)

    2016-09-15

    Autonomic self-healing materials are materials with built-in (micro-) capsules or vessels, which upon fracturing release healing agents in order to recover the material's physical and mechanical properties. In order to better understand and engineer these materials, a thorough characterization of the material's microstructural behavior is essential and often overlooked. In this context, micro-computed tomography (μCT) can be used to investigate the three dimensional distribution and (de)bonding of (micro-) capsules in their native state in a polymer system with self-healing properties. Furthermore, in-situ μCT experiments in a self-healing polymer and a self-healing concrete system can elucidate the breakage and leakage behavior of (micro-) capsules at the micrometer scale. While challenges related to image resolution and contrast complicate the characterization in specific cases, non-destructive 3D imaging with μCT is shown to contribute to the understanding of the link between the microstructure and the self-healing behavior of these complex materials. - Highlights: • μCT imaging allows for the analysis of microcapsule distribution patterns in self-healing materials. • μCT allows for qualitative and quantitative measurements of healing agent release from carriers in self-healing materials. • Experimental set-ups can be optimized by changing chemical compounds in the system to ensure maximum quality imaging.

  12. Software system safety

    Science.gov (United States)

    Uber, James G.

    1988-01-01

    Software itself is not hazardous, but since software and hardware share common interfaces there is an opportunity for software to create hazards. Further, these software systems are complex, and proven methods for the design, analysis, and measurement of software safety are not yet available. Some past software failures, future NASA software trends, software engineering methods, and tools and techniques for various software safety analyses are reviewed. Recommendations to NASA are made based on this review.

  13. Tritium permeation barrier based on self-healing composite materials

    International Nuclear Information System (INIS)

    Gao Jifeng; Zhang Dan; Suo Jinping

    2010-01-01

    Pores and cracks in ceramic coatings is one of the most important problems to be solved for the thermally sprayed tritium permeation barriers (TPBs) in fusion reactor. In this work, we developed a self-healing composite coating to address this problem. The coating composed of TiC + mixture(TiC/Al 2 O 3 ) + Al 2 O 3 was deposited on martensitic steels by means of atmospheric plasma spraying (APS). Before and after heat treatment, the morphology and phase of the coating were comparatively investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). In the experiment, NiAl + Al 2 O 3 , mixture(TiC/Al 2 O 3 ) + Al 2 O 3 and NiAl + TiC + mixture(TiC/Al 2 O 3 ) + Al 2 O 3 films were also fabricated and studied, respectively. The results showed that the TiC + mixture(TiC/Al 2 O 3 ) + Al 2 O 3 coating exhibited the best self-healing ability and good thermal shock resistance among the four samples after heat treatment under normal atmosphere. The SEM images analyzed by Image Pro software indicated that the porosity of the TiC + mixture(TiC/Al 2 O 3 ) + Al 2 O 3 coating decreased more than 90% in comparison with the sample before heat treatment. This self-healing coating made by thermal spraying might be a good candidate for tritium permeation barrier in fusion reactors.

  14. Dynamic reliability networks with self-healing units

    International Nuclear Information System (INIS)

    Jenab, K.; Seyed Hosseini, S.M.; Dhillon, B.S.

    2008-01-01

    This paper presents an analytical approach for dynamic reliability networks used for the failure limit strategy in maintenance optimization. The proposed approach utilizes the moment generating function (MGF) and the flow-graph concept to depict the functional and reliability diagrams of the system comprised of series, parallel or mix configuration of self-healing units. The self-healing unit is featured by the embedded failure detection and recovery mechanisms presented by self-loop in flow-graph networks. The newly developed analytical approach provides the probability of the system failure and time-to-failure data i.e., mean and standard deviation time-to-failure used for maintenance optimization

  15. Automated Manufacture of Damage Detecting, Self-Healing Composite Cryogenic Pressure Vessels, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — After successfully demonstrating the basic functionality of a damage-detecting, self-healing 'smart' material system in Phase I, Aurora and UMass Lowell aim to...

  16. Functionalized Agarose Self-Healing Ionogels Suitable for Supercapacitors.

    Science.gov (United States)

    Trivedi, Tushar J; Bhattacharjya, Dhrubajyoti; Yu, Jong-Sung; Kumar, Arvind

    2015-10-12

    Agarose has been functionalized (acetylated/carbanilated) in an ionic liquid (IL) medium of 1-butyl-3-methylimidazolium acetate at ambient conditions. The acetylated agarose showed a highly hydrophobic nature, whereas the carbanilated agarose could be dissolved in water as well as in the IL medium. Thermoreversible ionogels were obtained by cooling the IL sols of carbanilated agarose at room temperature. The ionogel prepared from a protic-aprotic mixed-IL system (1-butyl-3-methylimidazolium chloride and N-(2-hydroxyethyl)ammonium formate) demonstrated a superior self-healing property, as confirmed from rheological measurements. The superior self-healing property of such an ionogel has been attributed to the unique inter-intra hydrogen-bonding network of functional groups inserted in the agarose. The ionogel was tested as a flexible solid electrolyte for an activated-carbon-based supercapacitor cell. The measured specific capacitance was found to be comparable with that of a liquid electrolyte system at room temperature and was maintained for up to 1000 charge-discharge cycles. Such novel functionalized-biopolymer self-healing ionogels with flexibility and good conductivity are desirable for energy-storage devices and electronic skins with superior lifespans and robustness. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Development of Composites with a Self-Healing Function

    Directory of Open Access Journals (Sweden)

    Andrey ANISKEVICH

    2015-03-01

    Full Text Available This research aimed to realize experimentally the facilevascular self-healing system in epoxy glass fibre reinforced composite. Using flexiblepolytetrafluoroethylene tubes as removable preforms, the channels were embeddedinto both neat epoxy resin and unidirectional glass-fibre reinforced epoxy laminate.Room temperature curable epoxy resin with a surfactant and an amine-basedhardener were the components of the binary healing agent. The specimens oftapered double cantilever beam geometry were subjected to Mode I fracture tests.Fracture of specimens released the healing agent from channels and triggeredself-healing process of the crack. Tested neat epoxy resin specimensdemonstrated recovery of fracture toughness ca. 70 % after 24 h of self-healingat 50°C. Unidirectional laminate specimens (250×23×1.2 mm were made by vacuuminfusion method from two layers of glass yarns with 5 embedded channels aligningto reinforcing fibers. The channels were alternately filled with components of thehealing agent and then sealed. It was revealed that the embedded vascularchannels in specimens had very little effect on their elastic modulus. Theexperimental program included multiple three-point bending tests of specimensfor their initial damage and self-healing of specimens during their heat treatmentand following exposure at room temperature. Static and dynamic flexural moduli ofelasticity were determined by three-point bending and cantilever beam vibrationat all stages of the test program. The healing efficiency was evaluated as a relativechange of elastic modulus. The efficiency ca. 30 % was reached during 24 h at50°C and additionally increased up ca. 40 % after more than 3 weeks of roomtemperature exposure. The sealed healing agent was capable of maintaining thecapacity for self-healing for at least six months. The research resultsdemonstrated capacity of the macro-channel approach for self-healing realizationin multifunctional polymer composite materials

  18. Multifunctional Self-Healing and Morphing Composites

    National Research Council Canada - National Science Library

    Duenas, T; Bolanos, E; Murphy, E; Mal, A; Wudl, F; Schaffner, C; Wang, Y; Hahn, H. T; Ooi, T. K; Jha, A

    2006-01-01

    .... Proof of concept was demonstrated showing that a low volume-fraction (5-10%) of magnetic particles is sufficient for enabling self-healing of an approximate 150 micron x 5000 micron crack in a mendomer polymer using inductive heating...

  19. Wire Insulation Incorporating Self-Healing Polymers (WIISP), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NextGen and Virginia Tech are developing a self-healing material for wire insulation using a class of ionomeric polymers. These ionomers exhibit self-healing...

  20. The resilient hybrid fiber sensor network with self-healing function

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Shibo, E-mail: Shibo-Xu@tju.edu.cn; Liu, Tiegen; Ge, Chunfeng; Chen, Qinnan; Zhang, Hongxia [College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin 300072 (China); Key Laboratory of Opto-electronics Information Technology (Tianjin University), Ministry of Education, Tianjin 300072 (China)

    2015-03-15

    This paper presents a novel resilient fiber sensor network (FSN) with multi-ring architecture, which could interconnect various kinds of fiber sensors responsible for more than one measurands. We explain how the intelligent control system provides sensors with self-healing function meanwhile sensors are working properly, besides each fiber in FSN is under real-time monitoring. We explain the software process and emergency mechanism to respond failures or other circumstances. To improve the efficiency in the use of limited spectrum resources in some situations, we have two different structures to distribute the light sources rationally. Then, we propose a hybrid sensor working in FSN which is a combination of a distributed sensor and a FBG (Fiber Bragg Grating) array fused in a common fiber sensing temperature and vibrations simultaneously with neglectable crosstalk to each other. By making a failure to a working fiber in experiment, the feasibility and effectiveness of the network with a hybrid sensor has been demonstrated, hybrid sensors could not only work as designed but also survive from destructive failures with the help of resilient network and smart and quick self-healing actions. The network has improved the viability of the fiber sensors and diversity of measurands.

  1. The resilient hybrid fiber sensor network with self-healing function

    Science.gov (United States)

    Xu, Shibo; Liu, Tiegen; Ge, Chunfeng; Chen, Qinnan; Zhang, Hongxia

    2015-03-01

    This paper presents a novel resilient fiber sensor network (FSN) with multi-ring architecture, which could interconnect various kinds of fiber sensors responsible for more than one measurands. We explain how the intelligent control system provides sensors with self-healing function meanwhile sensors are working properly, besides each fiber in FSN is under real-time monitoring. We explain the software process and emergency mechanism to respond failures or other circumstances. To improve the efficiency in the use of limited spectrum resources in some situations, we have two different structures to distribute the light sources rationally. Then, we propose a hybrid sensor working in FSN which is a combination of a distributed sensor and a FBG (Fiber Bragg Grating) array fused in a common fiber sensing temperature and vibrations simultaneously with neglectable crosstalk to each other. By making a failure to a working fiber in experiment, the feasibility and effectiveness of the network with a hybrid sensor has been demonstrated, hybrid sensors could not only work as designed but also survive from destructive failures with the help of resilient network and smart and quick self-healing actions. The network has improved the viability of the fiber sensors and diversity of measurands.

  2. The resilient hybrid fiber sensor network with self-healing function

    International Nuclear Information System (INIS)

    Xu, Shibo; Liu, Tiegen; Ge, Chunfeng; Chen, Qinnan; Zhang, Hongxia

    2015-01-01

    This paper presents a novel resilient fiber sensor network (FSN) with multi-ring architecture, which could interconnect various kinds of fiber sensors responsible for more than one measurands. We explain how the intelligent control system provides sensors with self-healing function meanwhile sensors are working properly, besides each fiber in FSN is under real-time monitoring. We explain the software process and emergency mechanism to respond failures or other circumstances. To improve the efficiency in the use of limited spectrum resources in some situations, we have two different structures to distribute the light sources rationally. Then, we propose a hybrid sensor working in FSN which is a combination of a distributed sensor and a FBG (Fiber Bragg Grating) array fused in a common fiber sensing temperature and vibrations simultaneously with neglectable crosstalk to each other. By making a failure to a working fiber in experiment, the feasibility and effectiveness of the network with a hybrid sensor has been demonstrated, hybrid sensors could not only work as designed but also survive from destructive failures with the help of resilient network and smart and quick self-healing actions. The network has improved the viability of the fiber sensors and diversity of measurands

  3. Self-Healing Corrosion Protective Sol-Gel Coatings

    NARCIS (Netherlands)

    Abdolah Zadeh, M.

    2016-01-01

    Inspired by the state of the art and the recent advances in the field of self-healing corrosion protective coatings, the thesis entitled “Self-healing corrosion protective sol-gel coatings” addresses novel routes to self-healing corrosion protective sol-gel coatings via extrinsic and intrinsic

  4. Tritium permeation barrier based on self-healing composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Gao Jifeng; Zhang Dan [State Key Laboratory of Mould Technology, Institute of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Suo Jinping, E-mail: jpsuo@yahoo.com.cn [State Key Laboratory of Mould Technology, Institute of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2010-12-15

    Pores and cracks in ceramic coatings is one of the most important problems to be solved for the thermally sprayed tritium permeation barriers (TPBs) in fusion reactor. In this work, we developed a self-healing composite coating to address this problem. The coating composed of TiC + mixture(TiC/Al{sub 2}O{sub 3}) + Al{sub 2}O{sub 3} was deposited on martensitic steels by means of atmospheric plasma spraying (APS). Before and after heat treatment, the morphology and phase of the coating were comparatively investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). In the experiment, NiAl + Al{sub 2}O{sub 3}, mixture(TiC/Al{sub 2}O{sub 3}) + Al{sub 2}O{sub 3} and NiAl + TiC + mixture(TiC/Al{sub 2}O{sub 3}) + Al{sub 2}O{sub 3} films were also fabricated and studied, respectively. The results showed that the TiC + mixture(TiC/Al{sub 2}O{sub 3}) + Al{sub 2}O{sub 3} coating exhibited the best self-healing ability and good thermal shock resistance among the four samples after heat treatment under normal atmosphere. The SEM images analyzed by Image Pro software indicated that the porosity of the TiC + mixture(TiC/Al{sub 2}O{sub 3}) + Al{sub 2}O{sub 3} coating decreased more than 90% in comparison with the sample before heat treatment. This self-healing coating made by thermal spraying might be a good candidate for tritium permeation barrier in fusion reactors.

  5. Microencapsulation of Self-healing Concrete Properties

    Science.gov (United States)

    2012-08-01

    design and development. Other factors that can affect concrete and its lifespan include shrinkage , design flaws or poor quality of construction...possible shrinkage , design flaws or poor quality of construction materials, reinforced concrete will eventually develop cracks. Inevitable damage to...SELF-HEALING CONCRETE PROPERTIES N00244-l 0-G-0004 Sb. GRANT NUMBER Sc. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Sd. PROJECT NUMBER James Gilford III

  6. Self-Healing and Damage Resilience for Soft Robotics: A Review

    Directory of Open Access Journals (Sweden)

    R. Adam Bilodeau

    2017-10-01

    Full Text Available Advances in soft robotics will be crucial to the next generation of robot–human interfaces. Soft material systems embed safety at the material level, providing additional safeguards that will expedite their placement alongside humans and other biological systems. However, in order to function in unpredictable, uncontrolled environments alongside biological systems, soft robotic systems should be as robust in their ability to recover from damage as their biological counterparts. There exists a great deal of work on self-healing materials, particularly polymeric and elastomeric materials that can self-heal through a wide variety of tools and techniques. Fortunately, most emerging soft robotic systems are constructed from polymeric or elastomeric materials, so this work can be of immediate benefit to the soft robotics community. Though the field of soft robotics is still nascent as a whole, self-healing and damage resilient systems are beginning to be incorporated into three key support pillars that are enabling the future of soft robotics: actuators, structures, and sensors. This article reviews the state-of-the-art in damage resilience and self-healing materials and devices as applied to these three pillars. This review also discusses future applications for soft robots that incorporate self-healing capabilities.

  7. Software Intensive Systems

    National Research Council Canada - National Science Library

    Horvitz, E; Katz, D. J; Rumpf, R. L; Shrobe, H; Smith, T. B; Webber, G. E; Williamson, W. E; Winston, P. H; Wolbarsht, James L

    2006-01-01

    .... Additionally, recommend that DoN invest in software engineering, particularly as it complements commercial industry developments and promotes the application of systems engineering methodology...

  8. Layer-by-Layer Assembly of a Self-Healing Anticorrosion Coating on Magnesium Alloys.

    Science.gov (United States)

    Fan, Fan; Zhou, Chunyu; Wang, Xu; Szpunar, Jerzy

    2015-12-16

    Fabrication of self-healing anticorrosion coatings has attracted attention as it has the ability to extend the service life and prevent the substrate from corrosive attack. However, a coating system with a rapid self-healing ability and an improved corrosion resistance is rarely reported. In this work, we developed a self-healing anticorrosion coating on a magnesium alloy (AZ31). The coating comprises a cerium-based conversion layer, a graphene oxide layer, and a branched poly(ethylene imine) (PEI)/poly(acrylic acid) (PAA) multilayer. We incorporated the graphene oxide as corrosion inhibitors and used the PEI/PAA multilayers to provide the self-healing ability to the coating systems. X-ray diffraction (XRD) and Raman spectroscopy were used to characterize the composition of the multilayers, and scanning electron microscopy (SEM) was used to analyze the surface morphology. The electrochemical impedance spectroscopy (EIS) results illustrate the improved corrosion resistance of the coating. The proposed coating also has a rapid self-healing ability in the presence of water.

  9. Performance characteristics of a self-sealing/self-healing barrier

    International Nuclear Information System (INIS)

    McGregor, R.G.; Stegemann, J.A.

    1997-01-01

    Environment Canada and the Netherlands Energy Research Foundation are co-developers of a patented Self-Sealing/Self-Healing (SS/SH) Barrier system for containment of wastes which is licensed to Water Technology International Corporation. The SS/SH Barrier is intended for use as either a liner or cover for landfills, contaminated sites, secondary containment areas, etc., in the industrial, chemical, mining and municipal sectors, and also as a barrier to hydraulic flow for the transportation and construction industry. The SS/SH Barrier's most significant feature is its capability for self-repair in the event of a breach. By contrast, conventional barrier systems, such as clay, geomembrane, or geosynthetic clay liners can not be repaired without laborious excavation and reconstruction. Laboratory investigations have shown that the SS/SH Barrier concept will function with a variety of reactive materials. Self-Sealing/Self-Healing Barriers are cost competitive and consistently exhibit hydraulic conductivities ranging from 10 -9 to 10 -13 m/s, which decrease with time. These measurements meet or exceed the recommended hydraulic conductivity required by EPA for clay liners ( -9 m/s) used in landfills and hazardous waste sites. Results of mineralogical examination of the seal, diffusion testing, hydraulic conductivity measurement, and durability testing, including wet/dry, freeze/thaw cycling and leachate compatibility are also presented

  10. Self-healing Coatings for an Anti-corrosion barrier in Damaged Parts

    International Nuclear Information System (INIS)

    Cho, Soo Hyoun

    2009-01-01

    Polymer coatings are commonly applied to metal substrates to prevent corrosion in aggressive environments such as high humidity and under salt water. Once the polymer coating has been breached, for example due to cracking or scratches, it loses its effectiveness, and corrosion can rapidly propagate across the substrate. The self-healing system we will describe prevents corrosion by healing the damage through a healing reaction triggered by the actual damage event. This self-healing coating solution can be easily applied to most substrate materials, and our dual-capsule healing system provides a general approach to be compatible with most common polymer matrices. Specifically, we expect an excellent anti-corrosion property of the self-healing coatings in damaged parts coated on galvanized metal substrates.

  11. Development of self-healing polymers via amine–epoxy chemistry: II. Systematic evaluation of self-healing performance

    International Nuclear Information System (INIS)

    Zhang, He; Yang, Jinglei

    2014-01-01

    Part I of this study (H Zhang and J Yang 2014 Smart Mater. Struct. 23 065003) reported the preparation and characterization of epoxy microcapsules (EP-capsules) and amine loaded hollow glass bubbles (AM-HGBs), and the modeling of a two-part self-healing system. In part II, the self-healing performance of this material system is systematically investigated. Various factors including the ratio, the total concentration and the size of the two carriers are studied as well as the healing temperature and the post heat treatment process. The best healing performance is obtained at a ratio of 1:3 of EP-capsules to AM-HGBs. It is observed that a higher concentration of larger carriers, together with a higher healing temperature, enables better healing behavior. Healing efficiency of up to 93% is obtained in these systems. In addition, post heat treatment decreases the healing efficiency due to stoichiometric mismatch of healing agents caused by leakage of amine in the HGBs at elevated temperature. (paper)

  12. Development of self-healing polymers via amine-epoxy chemistry: II. Systematic evaluation of self-healing performance

    Science.gov (United States)

    Zhang, He; Yang, Jinglei

    2014-06-01

    Part I of this study (H Zhang and J Yang 2014 Smart Mater. Struct. 23 065003) reported the preparation and characterization of epoxy microcapsules (EP-capsules) and amine loaded hollow glass bubbles (AM-HGBs), and the modeling of a two-part self-healing system. In part II, the self-healing performance of this material system is systematically investigated. Various factors including the ratio, the total concentration and the size of the two carriers are studied as well as the healing temperature and the post heat treatment process. The best healing performance is obtained at a ratio of 1:3 of EP-capsules to AM-HGBs. It is observed that a higher concentration of larger carriers, together with a higher healing temperature, enables better healing behavior. Healing efficiency of up to 93% is obtained in these systems. In addition, post heat treatment decreases the healing efficiency due to stoichiometric mismatch of healing agents caused by leakage of amine in the HGBs at elevated temperature.

  13. Development of electrically insulating self-healing coatings in vanadium alloys for lithium fusion reactor

    International Nuclear Information System (INIS)

    1999-01-01

    Problems on electrically insulating self-healing coatings (SHC) on vanadium alloys for lithium fusion reactor systems are considered. In particular, the SHC stability and radiation resistance in lithium and effect of magnetic field on the efficiency of the TNR lithium systems are studied. New technological methods for application of self-healing coatings and study on their properties are developed. The vanadium-lithium materials testing in pile loops for solution of the above problems under conditions of the lithium TNR is described [ru

  14. A review on self-healing in reinforced concrete structures in view of serving conditions.

    NARCIS (Netherlands)

    Huang, H.; Ye, G.

    2014-01-01

    In this paper, different mechanisms of self-healing, i.e. self-healing based on adhesive agents, self-healing based on bacteria, self-healing based on autogenous self-healing were described. Their required conditions were summarized. The previous investigations showed that all mechanisms of

  15. Self-healing composites: in-situ repair solutions

    NARCIS (Netherlands)

    Coope, T.S.; Luterbacher, R.; Turkenburg, D.H.; Fischer, H.R.; Bond, I.P.

    2015-01-01

    Realising self-healing composites in a commercial environment remains a challenge for the transport sector. Herein, this research considers the design envelope and the implications of embedding self-healing agents into commercially relevant fibre reinforced polymer (FRP) composite applications. A

  16. Towards a fragment-based approach in gelator design: halogen effects leading to thixotropic, mouldable and self-healing systems in aryl-triazolyl amino acid-based gelators!

    Science.gov (United States)

    Srivastava, Bhartendu K; Manheri, Muraleedharan K

    2017-04-18

    A simple replacement of a H atom by Br transformed non-gelating aryl triazolyl amino acid benzyl ester into a versatile gelator, which formed shape-persistent, self-healing and mouldable gels. The 'bromo-aryl benzyl ester' fragment was then transplanted into another framework, which resulted in similar solvent preference and gelation efficiency.

  17. Security System Software

    Science.gov (United States)

    1993-01-01

    C Language Integration Production System (CLIPS), a NASA-developed expert systems program, has enabled a security systems manufacturer to design a new generation of hardware. C.CURESystem 1 Plus, manufactured by Software House, is a software based system that is used with a variety of access control hardware at installations around the world. Users can manage large amounts of information, solve unique security problems and control entry and time scheduling. CLIPS acts as an information management tool when accessed by C.CURESystem 1 Plus. It asks questions about the hardware and when given the answer, recommends possible quick solutions by non-expert persons.

  18. Local electrochemical evaluation of a self-healing coating based on encapsulated healing-agent

    NARCIS (Netherlands)

    González-García, Y.; García, S.J.; Fischer, H.R.; Hughes, A.E.; Mol, J.M.C.

    2011-01-01

    In this work local electrochemical techniques are introduced as powerful and complementary techniques for the in-situ evaluation of self-healing systems applied for the protection of metals against corrosion. Scanning vibrating electrode technique (SVET) and scanning electrochemical microscopy

  19. A probabilistic method for determining the volume fraction of pre-embedded capsules in self-healing materials

    International Nuclear Information System (INIS)

    Lv, Zhong; Chen, Huisu

    2014-01-01

    Autonomous healing of cracks using pre-embedded capsules containing healing agent is becoming a promising approach to restore the strength of damaged structures. In addition to the material properties, the size and volume fraction of capsules influence crack healing in the matrix. Understanding the crack and capsule interaction is critical in the development and design of structures made of self-healing materials. Assuming that the pre-embedded capsules are randomly dispersed we theoretically model flat ellipsoidal crack interaction with capsules and determine the probability of a crack intersecting the pre-embedded capsules i.e. the self-healing probability. We also develop a probabilistic model of a crack simultaneously meeting with capsules and catalyst carriers in two-component self-healing system matrix. Using a risk-based healing approach, we determine the volume fraction and size of the pre-embedded capsules that are required to achieve a certain self-healing probability. To understand the effect of the shape of the capsules on self-healing we theoretically modeled crack interaction with spherical and cylindrical capsules. We compared the results of our theoretical model with Monte-Carlo simulations of crack interaction with capsules. The formulae presented in this paper will provide guidelines for engineers working with self-healing structures in material selection and sustenance. (paper)

  20. Interfacial self-healing of nanocomposite hydrogels: Theory and experiment

    Science.gov (United States)

    Wang, Qiming; Gao, Zheming; Yu, Kunhao

    2017-12-01

    Polymers with dynamic bonds are able to self-heal their fractured interfaces and restore the mechanical strengths. It is largely elusive how to analytically model this self-healing behavior to construct the mechanistic relationship between the self-healing properties (e.g., healed interfacial strength and equilibrium healing time) and the material compositions and healing conditions. Here, we take a self-healable nanocomposite hydrogel as an example to illustrate an interfacial self-healing theory for hydrogels with dynamic bonds. In the theory, we consider the free polymer chains diffuse across the interface and reform crosslinks to bridge the interface. We analytically reveal that the healed strengths of nanocomposite hydrogels increase with the healing time in an error-function-like form. The equilibrium self-healing time of the full-strength recovery decreases with the temperature and increases with the nanoparticle concentration. We further analytically reveal that the healed interfacial strength decreases with increasing delaying time before the healing process. The theoretical results quantitatively match with our experiments on nanosilica hydrogels, and also agree well with other researchers' experiments on nanoclay hydrogels. We expect that this theory would open promising avenues for quantitative understanding of the self-healing mechanics of various polymers with dynamic bonds, and offer insights for designing high-performance self-healing polymers.

  1. CuAAC-Based Click Chemistry in Self-Healing Polymers.

    Science.gov (United States)

    Döhler, Diana; Michael, Philipp; Binder, Wolfgang H

    2017-10-17

    Click chemistry has emerged as a significant tool for materials science, organic chemistry, and bioscience. Based on the initial concept of Barry Sharpless in 2001, the copper(I)-catalyzed azide/alkyne cycloaddition (CuAAC) reaction has triggered a plethora of chemical concepts for linking molecules and building blocks under ambient conditions, forming the basis for applications in autonomous cross-linking materials. Self-healing systems on the other hand are often based on mild cross-linking chemistries that are able to react either autonomously or upon an external trigger. In the ideal case, self-healing takes place efficiently at low temperatures, independent of the substrate(s) used, by forming strong and stable networks, binding to the newly generated (cracked) interfaces to restore the original material properties. The use of the CuAAC in self-healing systems, most of all the careful design of copper-based catalysts linked to additives as well as the chemical diversity of substrates, has led to an enormous potential of applications of this singular reaction. The implementation of click-based strategies in self-healing systems therefore is highly attractive, as here chemical (and physical) concepts of molecular reactivity, molecular design, and even metal catalysis are connected to aspects of materials science. In this Account, we will show how CuAAC reactions of multivalent components can be used as a tool for self-healing materials, achieving cross-linking at low temperatures (exploiting concepts of autocatalysis or internal chelation within the bulk CuAAC and systematic optimization of the efficiency of the used Cu(I) catalysts). Encapsulation strategies to separate the click components by micro- and nanoencapsulation are required in this context. Consequently, the examples reported here describe chemical concepts to realize more efficient and faster click reactions in self-healing polymeric materials. Thus, enhanced chain diffusion in (hyper

  2. Self-Healing Superhydrophobic Materials Showing Quick Damage Recovery and Long-Term Durability.

    Science.gov (United States)

    Wang, Liming; Urata, Chihiro; Sato, Tomoya; England, Matt W; Hozumi, Atsushi

    2017-09-26

    Superhydrophobic coatings/materials are important for a wide variety of applications, but the majority of these man-made coatings/materials still suffer from poor durability because of their lack of self-healing ability. Here, we report novel superhydrophobic materials which can quickly self-heal from various severe types of damage. In this study, we used poly(dimethylsiloxane) (PDMS) infused with two liquids: trichloropropylsilane, which reacts with ambient moisture to self-assemble into grass-like microfibers (named silicone micro/nanograss) on the surfaces and low-viscosity silicone oil (SO), which remains within the PDMS matrices and acts as a self-healing agent. Because of the silicone micro/nanograss structures on the PDMS surfaces and the effective preserve/protection system of a large quantity of SO within the PDMS matrices, our superhydrophobic materials showed quick superhydrophobic recovery under ambient conditions (within 1-2 h) even after exposure to plasma (24 h), boiling water, chemicals, and outside environments. Such an ability is superior to the best self-healing superhydrophobic coatings/materials reported so far.

  3. Self-healing in fractured GaAs nanowires

    International Nuclear Information System (INIS)

    Wang Jun; Lu Chunsheng; Wang Qi; Xiao Pan; Ke Fujiu; Bai Yilong; Shen Yaogen; Wang Yanbo; Chen Bin; Liao Xiaozhou; Gao Huajian

    2012-01-01

    Molecular dynamics simulations are performed to investigate a spontaneous self-healing process in fractured GaAs nanowires with a zinc blende structure. The results show that such self-healing can indeed occur via rebonding of Ga and As atoms across the fracture surfaces, but it can be strongly influenced by several factors, including wire size, number of healing cycles, temperature, fracture morphology, oriented attachment and atomic diffusion. For example, it is found that the self-healing capacity is reduced by 46% as the lateral dimension of the wire increases from 2.3 to 9.2 nm, and by 64% after 24 repeated cycles of fracture and healing. Other factors influencing the self-healing behavior are also discussed.

  4. Multiple self-healing squamous epithelioma of Ferguson-Smith

    DEFF Research Database (Denmark)

    Broesby-Olsen, Sigurd; Bygum, Anette; Gerdes, Anne-Marie

    2008-01-01

    Multiple self-healing squamous epithelioma of Ferguson-Smith (MSSE) is a rare autosomal dominantly inherited disease, almost exclusively reported in patients of Scottish origin, with recurrent, histologically malignant tumours that undergo spontaneous regression. We report clinical observations...

  5. Unified Engineering Software System

    Science.gov (United States)

    Purves, L. R.; Gordon, S.; Peltzman, A.; Dube, M.

    1989-01-01

    Collection of computer programs performs diverse functions in prototype engineering. NEXUS, NASA Engineering Extendible Unified Software system, is research set of computer programs designed to support full sequence of activities encountered in NASA engineering projects. Sequence spans preliminary design, design analysis, detailed design, manufacturing, assembly, and testing. Primarily addresses process of prototype engineering, task of getting single or small number of copies of product to work. Written in FORTRAN 77 and PROLOG.

  6. Evolvable Neural Software System

    Science.gov (United States)

    Curtis, Steven A.

    2009-01-01

    The Evolvable Neural Software System (ENSS) is composed of sets of Neural Basis Functions (NBFs), which can be totally autonomously created and removed according to the changing needs and requirements of the software system. The resulting structure is both hierarchical and self-similar in that a given set of NBFs may have a ruler NBF, which in turn communicates with other sets of NBFs. These sets of NBFs may function as nodes to a ruler node, which are also NBF constructs. In this manner, the synthetic neural system can exhibit the complexity, three-dimensional connectivity, and adaptability of biological neural systems. An added advantage of ENSS over a natural neural system is its ability to modify its core genetic code in response to environmental changes as reflected in needs and requirements. The neural system is fully adaptive and evolvable and is trainable before release. It continues to rewire itself while on the job. The NBF is a unique, bilevel intelligence neural system composed of a higher-level heuristic neural system (HNS) and a lower-level, autonomic neural system (ANS). Taken together, the HNS and the ANS give each NBF the complete capabilities of a biological neural system to match sensory inputs to actions. Another feature of the NBF is the Evolvable Neural Interface (ENI), which links the HNS and ANS. The ENI solves the interface problem between these two systems by actively adapting and evolving from a primitive initial state (a Neural Thread) to a complicated, operational ENI and successfully adapting to a training sequence of sensory input. This simulates the adaptation of a biological neural system in a developmental phase. Within the greater multi-NBF and multi-node ENSS, self-similar ENI s provide the basis for inter-NBF and inter-node connectivity.

  7. Improving Kinetics of “Click-Crosslinking” for Self-Healing Nanocomposites by Graphene-Supported Cu-Nanoparticles

    Directory of Open Access Journals (Sweden)

    Neda Kargarfard

    2017-12-01

    Full Text Available Investigation of the curing kinetics of crosslinking reactions and the development of optimized catalyst systems is of importance for the preparation of self-healing nanocomposites, able to significantly extend their service lifetimes. Here we study different modified low molecular weight multivalent azides for a capsule-based self-healing approach, where self-healing is mediated by graphene-supported copper-nanoparticles, able to trigger “click”-based crosslinking of trivalent azides and alkynes. When monitoring the reaction kinetics of the curing reaction via reactive dynamic scanning calorimetry (DSC, it was found that the “click-crosslinking” reactivity decreased with increasing chain length of the according azide. Additionally, we could show a remarkable “click” reactivity already at 0 °C, highlighting the potential of click-based self-healing approaches. Furthermore, we varied the reaction temperature during the preparation of our tailor-made graphene-based copper(I catalyst to further optimize its catalytic activity. With the most active catalyst prepared at 700 °C and the optimized set-up of reactants on hand, we prepared capsule-based self-healing epoxy nanocomposites.

  8. Self-healing concrete by use of microencapsulated bacterial spores

    International Nuclear Information System (INIS)

    Wang, J.Y.; Soens, H.; Verstraete, W.; De Belie, N.

    2014-01-01

    Microcapsules were applied to encapsulate bacterial spores for self-healing concrete. The viability of encapsulated spores and the influence of microcapsules on mortar specimens were investigated first. Breakage of the microcapsules upon cracking was verified by Scanning Electron Microscopy. Self-healing capacity was evaluated by crack healing ratio and the water permeability. The results indicated that the healing ratio in the specimens with bio-microcapsules was higher (48%–80%) than in those without bacteria (18%–50%). The maximum crack width healed in the specimens of the bacteria series was 970 μm, about 4 times that of the non-bacteria series (max 250 μm). The overall water permeability in the bacteria series was about 10 times lower than that in non-bacteria series. Wet–dry cycles were found to stimulate self-healing in mortar specimens with encapsulated bacteria. No self-healing was observed in all specimens stored at 95%RH, indicating that the presence of liquid water is an essential component for self-healing

  9. Self-healing concrete by use of microencapsulated bacterial spores

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.Y. [Magnel Laboratory for Concrete Research, Faculty of Engineering and Architecture, Ghent University, TechnologieparkZwijnaarde 904, B-9052 Ghent (Belgium); Laboratory of Microbial Ecology and Technology (LabMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent (Belgium); Soens, H. [Devan Chemicals NV, Klein Frankrijk 18, 9600 Ronse (Belgium); Verstraete, W. [Laboratory of Microbial Ecology and Technology (LabMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent (Belgium); De Belie, N., E-mail: nele.debelie@ugent.be [Magnel Laboratory for Concrete Research, Faculty of Engineering and Architecture, Ghent University, TechnologieparkZwijnaarde 904, B-9052 Ghent (Belgium)

    2014-02-15

    Microcapsules were applied to encapsulate bacterial spores for self-healing concrete. The viability of encapsulated spores and the influence of microcapsules on mortar specimens were investigated first. Breakage of the microcapsules upon cracking was verified by Scanning Electron Microscopy. Self-healing capacity was evaluated by crack healing ratio and the water permeability. The results indicated that the healing ratio in the specimens with bio-microcapsules was higher (48%–80%) than in those without bacteria (18%–50%). The maximum crack width healed in the specimens of the bacteria series was 970 μm, about 4 times that of the non-bacteria series (max 250 μm). The overall water permeability in the bacteria series was about 10 times lower than that in non-bacteria series. Wet–dry cycles were found to stimulate self-healing in mortar specimens with encapsulated bacteria. No self-healing was observed in all specimens stored at 95%RH, indicating that the presence of liquid water is an essential component for self-healing.

  10. Autonomous stimulus triggered self-healing in smart structural composites

    International Nuclear Information System (INIS)

    Norris, C J; White, J A P; McCombe, G; Chatterjee, P; Bond, I P; Trask, R S

    2012-01-01

    Inspired by the ability of biological systems to sense and autonomously heal damage, this research has successfully demonstrated the first autonomous, stimulus triggered, self-healing system in a structural composite material. Both the sensing and healing mechanisms are reliant on microvascular channels incorporated within a laminated composite material. For the triggering mechanism, a single air filled vessel was pressurized, sealed and monitored. Upon drop weight impact (10 J), delamination and microcrack connectivity between the pressurized vessel and those open to ambient led to a pressure loss which, with the use of a suitable sensor, triggered a pump to deliver a healing agent to the damage zone. Using this autonomous healing approach, near full recovery of post-impact compression strength was achieved (94% on average). A simplified alternative system with healing agent continuously flowing through the vessels, akin to blood flow, was found to offer 100% recovery of the material’s virgin strength. Optical microscopy and ultrasonic C-scanning provided further evidence of large-scale infusion of matrix damage with the healing agent. The successful implementation of this bioinspired technology could substantially enhance the integrity and reliability of aerospace structures, whilst offering benefits through improved performance/weight ratios and extended lifetimes. (paper)

  11. Dynamic Self-Healing Mechanism for Transactional Business Process

    Directory of Open Access Journals (Sweden)

    Yuhai Zhao

    2015-01-01

    Full Text Available It is clear that transactional behavior consistency is a prerequisite and basis for construction of a reliable services-based business application. However, in previous works, maintaining transactional consistency during exception handling was ignored. Maintaining transactional consistency requires functionality for rolling back some operations and revoking uploaded data. Replacing only the failed service will eventually lead to overall business application failure. In this study, we take fully into account the behavioral consistency of transactional services and propose two effective self-healing mechanisms for service-based applications. If a service enters into potential failure condition, a rescheduling mechanism is triggered to maintain consistent transactional behavior and to ensure reliable execution; if a service fails during execution, the compensation operation is triggered and the system will take action to ensure transactional behavior consistency. Meanwhile, cost-benefit analysis with compensation support is proposed to minimize the dynamic reselection cost. Finally, the experimental analysis shows that the proposed strategies can effectively guarantee the reliability of Web-based applications system.

  12. Cementitious composite materials with improved self-healing potential

    Directory of Open Access Journals (Sweden)

    Cornelia BAERA

    2015-12-01

    Full Text Available Cement-based composites have proved, over the time, certain abilities of self-healing the damages (cracks and especially microcracs that occur within their structure. Depending on the level of damage and of the composite type in which this occurs, the self - healing process (SH can range from crack closing or crack sealing to the stage of partial or even complete recovery of material physical - mechanical properties. The aim of this paper is to present the general concept of Engineered Cementitious Composites (ECCs with their unique properties including their self-healing (SH capacity, as an innovative direction for a global sustainable infrastructure. The experimental steps initiated for the development in Romania of this unique category of materials, using materials available on the local market, are also presented.

  13. Thermally driven self-healing using copper nanofiber heater

    Science.gov (United States)

    Lee, Min Wook; Jo, Hong Seok; Yoon, Sam S.; Yarin, Alexander L.

    2017-07-01

    Nano-textured transparent heaters made of copper nanofibers (CuNFs) are used to facilitate accelerated self-healing of bromobutyl rubber (BIIR). The heater and BIIR layer are separately deposited on each side of a transparent flexible polyethylene terephthalate (PET) substrate. A pre-notched crack on the BIIR layer was bridged due to heating facilitated by CuNFs. In the corrosion test, a cracked BIIR layer covered a steel substrate. An accelerated self-healing of the crack due to the transparent copper nanofiber heater facilitated an anti-corrosion protective effect of the BIIR layer.

  14. Novel Diels-Alder based self-healing epoxies for aerospace composites

    Science.gov (United States)

    Coope, T. S.; Turkenburg, D. H.; Fischer, H. R.; Luterbacher, R.; van Bracht, H.; Bond, I. P.

    2016-08-01

    Epoxy resins containing Diels-Alder (DA) furan and maleimide moieties are presented with the capability to self-heal after exposure to an external heat source. A conventional epoxy amine system has been combined with furfuryl and maleimide functional groups in a two-step process, to avoid major side-reactions, and the concentration of a thermo-reversibly binding cross-linker was considered to balance thermoset and thermoplastic behaviours, and the subsequent self-healing performance. In the context of self-repair technologies an inbuilt ‘intrinsic’ self-healing system is deemed favourable as the healing agent can be placed in known ‘hot spot’ regions (i.e. skin-stringer run outs, ply drops and around drilled holes) where operational damage predominately occurs in load bearing aerospace structures. In this study, the mechanical and self-healing performance of furan functionalised epoxy resins containing varying amounts (10, 20, 30 or 40 pph) of bismaleimide were investigated using a bulk epoxy polymer tapered double cantilever beam test specimen geometry. Two forms, a thin film and a bulk material, were evaluated to account for future integration methods into fibre reinforced polymer (FRP) composites. The highest healing efficiency, with respect to the obtained initial load value, was observed from the 20 pph bulk material derivative. The polymers were successful in achieving consistent multiple (three) healing cycles when heated at 150 °C for 5 min. This novel investigated DA material exhibits favourable processing characteristics for FRP composites as preliminary studies have shown successful coextrution with reinforcing fibres to form free standing films and dry fibre impregnation.

  15. Software for microcircuit systems

    International Nuclear Information System (INIS)

    Kunz, P.F.

    1978-10-01

    Modern Large Scale Integration (LSI) microcircuits are meant to be programed in order to control the function that they perform. The basics of microprograming and new microcircuits have already been discussed. In this course, the methods of developing software for these microcircuits are explored. This generally requires a package of support software in order to assemble the microprogram, and also some amount of support software to test the microprograms and to test the microprogramed circuit itself. 15 figures, 2 tables

  16. Self-Healing Natural Rubber with Tailorable Mechanical Properties Based on Ionic Supramolecular Hybrid Network.

    Science.gov (United States)

    Xu, Chuanhui; Cao, Liming; Huang, Xunhui; Chen, Yukun; Lin, Baofeng; Fu, Lihua

    2017-08-30

    In most cases, the strength of self-healing supramolecular rubber based on noncovalent bonds is in the order of KPa, which is a challenge for their further applications. Incorporation of conventional fillers can effectively enhance the strength of rubbers, but usually accompanied by a sacrifice of self-healing capability due to that the filler system is independent of the reversible supramolecular network. In the present work, in situ reaction of methacrylic acid (MAA) and excess zinc oxide (ZnO) was realized in natural rubber (NR). Ionic cross-links in NR matrix were obtained by limiting the covalent cross-linking of NR molecules and allowing the in situ polymerization of MAA/ZnO. Because of the natural affinity between Zn 2+ ion-rich domains and ZnO, the residual nano ZnO participated in formation of a reversible ionic supramolecular hybrid network, thus having little obstructions on the reconstruction of ionic cross-links. Meanwhile, the well dispersed residual ZnO could tailor the mechanical properties of NR by changing the MAA/ZnO molar ratios. The present study thus provides a simple method to fabricate a new self-healing NR with tailorable mechanical properties that may have more potential applications.

  17. Simulation of the self-healing of dolomitic lime mortar

    NARCIS (Netherlands)

    Lubelli, B.; Nijland, T.G.; Hees, R.P.J. van

    2012-01-01

    A test procedure was set up to reproduce laboratory self-healing on lime-based (both pure calcium and magnesium-calcium) mortar specimens. After a few months of testing, during which time the specimens were submitted to wet-dry cycles, thin sections of the specimens were prepared and observed using

  18. Simulation of self-healing of dolomitic lime mortar

    NARCIS (Netherlands)

    Lubelli, B.; Nijland, T.G.; Van Hees, R.P.J.

    2011-01-01

    In the present research a test procedure was set up to reproduce self-healing on lime-based (both pure calcium and magnesium-calcium) mortar specimens in laboratory. After few months testing, during which the specimens were subjected to wet-dry cycles, thin sections of the specimens were prepared

  19. Self healing of damage in Fe-based alloys

    NARCIS (Netherlands)

    Zhang, S.

    2015-01-01

    Steel components can exhibit premature and low-ductility creep fracture, when exposed to high temperatures for long times. The failure arises from the formation, growth and coalescence of ultra-fine cracks and cavities. Self healing of damage is a promising new approach to enhance the lifetime of

  20. Congenital self-healing reticulohistiocytosis - an important diagnostic challenge

    DEFF Research Database (Denmark)

    Jensen, Marie Louise Slott; Bygum, Anette; Clemmensen, Ole

    2011-01-01

    Aim:  To present current and new knowledge on congenital self-healing reticulohistiocytosis, a benign variant of cutaneous Langerhans cell histiocytosis presenting with skin lesions in the neonatal period. Methods:  We describe and photo document two cases of this rare disease and review the lite......Aim:  To present current and new knowledge on congenital self-healing reticulohistiocytosis, a benign variant of cutaneous Langerhans cell histiocytosis presenting with skin lesions in the neonatal period. Methods:  We describe and photo document two cases of this rare disease and review...... the literature. Results:  Only few newborns have acute access to a neonatal dermatologist and we demonstrate how the spontaneous cutaneous involution may happen even prior to the first dermatological assessment. As no sole criterion can reliably distinguish the self-healing form from disseminated disease......, multidisciplinary assessment and follow up are essential. Conclusion:  Our data document how easily the diagnosis congenital self-healing reticulocytosis may be missed and emphasize the importance and value of instant clinical photographing at the neonatal unit and the use of teledermatology whenever congenital...

  1. Multifunctional Polymers and Composites for Self-Healing Applications

    Science.gov (United States)

    2006-09-30

    N,N’-dicyclohexylcarbodiimide (DCC) was obtained from Avocado . Reagent grade ether was purchased from Malinckrodt and anhydrous methylene chloride...several companies through sponsored research agreements to transition self-healing technology into the commercial market . These agreements include

  2. Proteinaceous Resin and Hydrophilic Encapsulation: A Self-Healing-Related Study

    Science.gov (United States)

    Zheng, Ting

    Inspired by living organisms, self-healing materials have been designed as smart materials. Their automatic healing nature is achieved through the use of capsule in which the healing agent is encapsulated. The occurrence of cracks leads to ripping of the capsule, along with crack propagation and release of the healing agent that wets the crack surface to eventually heal (bond) the crack. Such automatic repair of the crack significantly extends the service life of the material. A vast majority of existing self-healing systems have been designed for the epoxy matrix - the most common commercially used thermoset - that possesses low crack resistance. Currently, self-healing systems have not yet been introduced for fully protein-based materials, despite their great potential to replace currently used synthesis precursors for the latter and the eco-friendly nature of self-healing materials. This has been probably due to two major obstacles: poor mechanical properties of the protein-based matrix, and extreme difficulty associated with the encapsulation of hydrophilic healing agents suitable for the protein-based matrix. This study provides possible solutions towards addressing both these obstacles. To improve the inherent mechanical properties of protein-based resin, soy protein isolate (SPI) was chosen as the model in this study. Dialdehyde carboxymethyl cellulose (DCMC) was synthesized and used as the crosslinking agent to modify the SPI film. As-synthesized DCMC - a fully bio-based material - exhibited high mechanical strength, excellent thermal stability, and reduced moisture sensitivity. Good compatibility and effective crosslinking were believed to be the key reasons for such property enhancements. However, these were accompanied by poor crack resistance, where self-healing is a pertinent solution. A novel healing system for the protein matrix was designed in this work via the use of formaldehyde as a healing agent. Subsequently, the well-acknowledged challenge, e

  3. Software for microcircuit systems

    International Nuclear Information System (INIS)

    Kunz, P.F.

    1978-01-01

    Modern Large Scale Integration (LSI) microcircuits are meant to be programmed in order to control the function that they perform. In the previous paper the author has already discussed the basics of microprogramming and have studied in some detail two types of new microcircuits. In this paper, methods of developing software for these microcircuits are explored. This generally requires a package of support software in order to assemble the microprogram, and also some amount of support software to test the microprograms and to test the microprogrammed circuit itself. (Auth.)

  4. A review: Self-healing in cementitious materials and engineered cementitious composite as a self-healing material

    DEFF Research Database (Denmark)

    Wu, Min; Johannesson, Björn; Geiker, Mette

    2012-01-01

    .e. the use of hollow fibers, microencapsulation, expansive agents and mineral admixtures, bacteria and shape memory materials, are reviewed and summarized. A comparison study is conducted subsequently on different strategies to self-healing and on different healing agents used as well. Engineered...

  5. Recommendation systems in software engineering

    CERN Document Server

    Robillard, Martin P; Walker, Robert J; Zimmermann, Thomas

    2014-01-01

    With the growth of public and private data stores and the emergence of off-the-shelf data-mining technology, recommendation systems have emerged that specifically address the unique challenges of navigating and interpreting software engineering data.This book collects, structures and formalizes knowledge on recommendation systems in software engineering. It adopts a pragmatic approach with an explicit focus on system design, implementation, and evaluation. The book is divided into three parts: "Part I - Techniques" introduces basics for building recommenders in software engineering, including techniques for collecting and processing software engineering data, but also for presenting recommendations to users as part of their workflow.?"Part II - Evaluation" summarizes methods and experimental designs for evaluating recommendations in software engineering.?"Part III - Applications" describes needs, issues and solution concepts involved in entire recommendation systems for specific software engineering tasks, fo...

  6. Self-healing of lime based mortars : Microscopy observations on case studies

    NARCIS (Netherlands)

    Lubelli, B.; Nijland, T.G.; Van Hees, R.P.J.

    2011-01-01

    Lime mortars have, up to a certain extent, a self-healing capacity which may contribute to their durability. Self-healing in lime mortars consists of a process of dissolution, transport and re-precipitation of calcium compounds to heal cracks and fissures. The spontaneous occurrence of self-healing

  7. Self-healing of lime based mortars: Microscopy observations on case studies

    NARCIS (Netherlands)

    Lubelli, B.; Nijland, T.G.; Hees, R.P.J. van

    2011-01-01

    Lime mortars have, up to a certain extent, a self-healing capacity which may contribute to their durability. Self-healing in lime mortars consists of a process of dissolution, transport and re-precipitation of calcium compounds to heal cracks and fissures. The spontaneous occurrence of self-healing

  8. Self-healing of Bessel-like beams with longitudinally dependent cone angles

    CSIR Research Space (South Africa)

    Litvin, I

    2015-09-01

    Full Text Available non-diffracting propagation region. Here we show that such beams can self-heal. Moreover, in contrast to Bessel beams where the self-healing distance is constant, here the self-healing distance is dependent on where the obstruction is placed...

  9. Development of an autonomous setup for evaluating self healing capability of asphalt mixtures

    NARCIS (Netherlands)

    Qiu, J.; Molenaar, A.A.A.; Van de Ven, M.F.C.; Wu, S.

    2012-01-01

    It is a well known fact that asphalt mixtures have self healing capabilities. Yet most of the self healing investigations are carried out using complex and time consuming fatigue tests. In order to investigate the self healing capability in a simple and efficient manner, a beam on elastic foundation

  10. System support software for TSTA

    International Nuclear Information System (INIS)

    Claborn, G.W.; Mann, L.W.; Nielson, C.W.

    1987-01-01

    The software at the Tritium Systems Test Assembly (TSTA) is logically broken into two parts, the system support software and the subsystem software. The purpose of the system support software is to isolate the subsystem software from the physical hardware. In this sense the system support software forms the kernel of the software at TSTA. The kernel software performs several functions. It gathers data from CAMAC modules and makes that data available for subsystem processes. It services requests to send commands to CAMAC modules. It provides a system of logging functions and provides for a system-wide global program state that allows highly structured interaction between subsystem processes. The kernel's most visible function is to provide the Man-Machine Interface (MMI). The MMI allows the operators a window into the physical hardware and subsystem process state. Finally the kernel provides a data archiving and compression function that allows archival data to be accessed and plotted. Such kernel software as developed and implemented at TSTA is described

  11. Self-healing of drying shrinkage cracks in cement-based materials incorporating reactive MgO

    Science.gov (United States)

    Qureshi, T. S.; Al-Tabbaa, A.

    2016-08-01

    Excessive drying shrinkage is one of the major issues of concern for longevity and reduced strength performance of concrete structures. It can cause the formation of cracks in the concrete. This research aims to improve the autogenous self-healing capacity of traditional Portland cement (PC) systems, adding expansive minerals such as reactive magnesium oxide (MgO) in terms of drying shrinkage crack healing. Two different reactive grades (high ‘N50’and moderately high ‘92-200’) of MgO were added with PC. Cracks were induced in the samples with restraining end prisms through natural drying shrinkage over 28 days after casting. Samples were then cured under water for 28 and 56 days, and self-healing capacity was investigated in terms of mechanical strength recovery, crack sealing efficiency and improvement in durability. Finally, microstructures of the healing materials were investigated using FT-IR, XRD, and SEM-EDX. Overall N50 mixes show higher expansion and drying shrinkage compared to 92-200 mixes. Autogenous self-healing performance of the MgO containing samples were much higher compared to control (only PC) mixes. Cracks up to 500 μm were sealed in most MgO containing samples after 28 days. In the microstructural investigations, highly expansive Mg-rich hydro-carbonate bridges were found along with traditional calcium-based, self-healing compounds (calcite, portlandite, calcium silicate hydrates and ettringite).

  12. Skin-Inspired Multifunctional Autonomic-Intrinsic Conductive Self-Healing Hydrogels with Pressure Sensitivity, Stretchability, and 3D Printability.

    Science.gov (United States)

    Darabi, Mohammad Ali; Khosrozadeh, Ali; Mbeleck, Rene; Liu, Yuqing; Chang, Qiang; Jiang, Junzi; Cai, Jun; Wang, Quan; Luo, Gaoxing; Xing, Malcolm

    2017-08-01

    The advent of conductive self-healing (CSH) hydrogels, a class of novel materials mimicking human skin, may change the trajectory of the industrial process because of their potential applications in soft robots, biomimetic prostheses, and health-monitoring systems. Here, the development of a mechanically and electrically self-healing hydrogel based on physically and chemically cross-linked networks is reported. The autonomous intrinsic self-healing of the hydrogel is attained through dynamic ionic interactions between carboxylic groups of poly(acrylic acid) and ferric ions. A covalent cross-linking is used to support the mechanical structure of the hydrogel. Establishing a fair balance between the chemical and physical cross-linking networks together with the conductive nanostructure of polypyrrole networks leads to a double network hydrogel with bulk conductivity, mechanical and electrical self-healing properties (100% mechanical recovery in 2 min), ultrastretchability (1500%), and pressure sensitivity. The practical potential of CSH hydrogels is further revealed by their application in human motion detection and their 3D-printing performance. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Self-Healing Supramolecular Hydrogels Based on Reversible Physical Interactions

    Directory of Open Access Journals (Sweden)

    Satu Strandman

    2016-04-01

    Full Text Available Dynamic and reversible polymer networks capable of self-healing, i.e., restoring their mechanical properties after deformation and failure, are gaining increasing research interest, as there is a continuous need towards extending the lifetime and improving the safety and performance of materials particularly in biomedical applications. Hydrogels are versatile materials that may allow self-healing through a variety of covalent and non-covalent bonding strategies. The structural recovery of physical gels has long been a topic of interest in soft materials physics and various supramolecular interactions can induce this kind of recovery. This review highlights the non-covalent strategies of building self-repairing hydrogels and the characterization of their mechanical properties. Potential applications and future prospects of these materials are also discussed.

  14. Bioinspired self-healing materials: lessons from nature

    Science.gov (United States)

    Cremaldi, Joseph C

    2018-01-01

    Healing is an intrinsic ability in the incredibly biodiverse populations of the plant and animal kingdoms created through evolution. Plants and animals approach healing in similar ways but with unique pathways, such as damage containment in plants or clotting in animals. After analyzing the examples of healing and defense mechanisms found in living nature, eight prevalent mechanisms were identified: reversible muscle control, clotting, cellular response, layering, protective surfaces, vascular networks or capsules, exposure, and replenishable functional coatings. Then the relationship between these mechanisms, nature’s best (evolutionary) methods of mitigating and healing damage, and existing technology in self-healing materials are described. The goals of this top-level overview are to provide a framework for relating the behavior seen in living nature to bioinspired materials, act as a resource to addressing the limitations/problems with existing materials, and open up new avenues of insight and research into self-healing materials. PMID:29600152

  15. Software Build and Delivery Systems

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-10

    This presentation deals with the hierarchy of software build and delivery systems. One of the goals is to maximize the success rate of new users and developers when first trying your software. First impressions are important. Early successes are important. This also reduces critical documentation costs. This is a presentation focused on computer science and goes into detail about code documentation.

  16. Self-Healing Phase Change Salogels with Tunable Gelation Temperature.

    Science.gov (United States)

    Karimineghlani, Parvin; Palanisamy, Anbazhagan; Sukhishvili, Svetlana A

    2018-04-19

    Chemically cross-linked polymer matrices have demonstrated strong potential for shape stabilization of molten phase change materials (PCM). However, they are not designed to be fillable and removable from a heat exchange module for an easy replacement with new PCM matrices and lack self-healing capability. Here, a new category of shapeable, self-healing gels, "salogels", is introduced. The salogels reversibly disassemble in a high-salinity environment of a fluid inorganic PCM [lithium nitrate trihydrate (LNH)], at a preprogrammed temperature. LNH was employed as a high latent heat PCM and simultaneously as a solvent, which supported the formation of a network of polyvinyl alcohol (PVA) chains via physical cross-linking through poly(amidoamine) dendrimers of various generations. The existence of hydrogen bonding and the importance of low-hydration state of PVA for the efficient gelation were experimentally confirmed. The thermal behavior of PCM salogels was highly reversible and repeatable during multiple heating/cooling cycles. Importantly, the gel-sol transition temperature could be precisely controlled within a range of temperature above LNH's melting point by the choice of dendrimer generation and their concentration. Shape stabilization and self-healing properties of the salogels, taken together with tunability of their temperature-induced fluidization make these materials attractive for thermal energy storage applications that require on-demand removal and replacement of used inorganic PCM salt hydrates.

  17. A highly stretchable autonomous self-healing elastomer

    Science.gov (United States)

    Li, Cheng-Hui; Wang, Chao; Keplinger, Christoph; Zuo, Jing-Lin; Jin, Lihua; Sun, Yang; Zheng, Peng; Cao, Yi; Lissel, Franziska; Linder, Christian; You, Xiao-Zeng; Bao, Zhenan

    2016-06-01

    It is a challenge to synthesize materials that possess the properties of biological muscles—strong, elastic and capable of self-healing. Herein we report a network of poly(dimethylsiloxane) polymer chains crosslinked by coordination complexes that combines high stretchability, high dielectric strength, autonomous self-healing and mechanical actuation. The healing process can take place at a temperature as low as -20 °C and is not significantly affected by surface ageing and moisture. The crosslinking complexes used consist of 2,6-pyridinedicarboxamide ligands that coordinate to Fe(III) centres through three different interactions: a strong pyridyl-iron one, and two weaker carboxamido-iron ones through both the nitrogen and oxygen atoms of the carboxamide groups. As a result, the iron-ligand bonds can readily break and re-form while the iron centres still remain attached to the ligands through the stronger interaction with the pyridyl ring, which enables reversible unfolding and refolding of the chains. We hypothesize that this behaviour supports the high stretchability and self-healing capability of the material.

  18. pH-responsive self-healing injectable hydrogel based on N-carboxyethyl chitosan for hepatocellular carcinoma therapy.

    Science.gov (United States)

    Qu, Jin; Zhao, Xin; Ma, Peter X; Guo, Baolin

    2017-08-01

    Injectable hydrogels with pH-responsiveness and self-healing ability have great potential for anti-cancer drug delivery. Herein, we developed a series of polysaccharide-based self-healing hydrogels with pH-sensitivity as drug delivery vehicles for hepatocellular carcinoma therapy. The hydrogels were prepared by using N-carboxyethyl chitosan (CEC) synthesized via Michael reaction in aqueous solution and dibenzaldehyde-terminated poly(ethylene glycol) (PEGDA). Doxorubicin (Dox), as a model of water-soluble small molecule anti-cancer drug was encapsulated into the hydrogel in situ. Self-healing behavior of the hydrogels was investigated at microscopic and macroscopic levels, and the hydrogels showed rapid self-healing performance without any external stimulus owing to the dynamic covalent Schiff-base linkage between amine groups from CEC and benzaldehyde groups from PEGDA. The chemical structures, rheological property, in vitro gel degradation, morphology, gelation time and in vitro Dox release behavior from the hydrogels were characterized. Injectability was verified by in vitro injection and in vivo subcutaneous injection in a rat. pH-responsive behavior was verified by in vitro Dox release from hydrogels in PBS solutions with different pH values. Furthermore, the activity of Dox released from hydrogel matrix was evaluated by employing human hepatocellular liver carcinoma (HepG2). Cytotoxicity test of the hydrogels using L929 cells confirmed their good cytocompatibility. Together, these pH-responsive self-healing injectable hydrogels are excellent candidates as drug delivery vehicles for liver cancer treatment. STATEMENT OF SIGNIFICANCE: pH-responsive drug delivery system could release drug efficiently in targeted acid environment and minimalize the amount of drug release in normal physiological environment. pH-sensitive injectable hydrogels as smart anti-cancer drug delivery carriers show great potential application for cancer therapy. The hydrogels with self-healing

  19. System Software 7 Macintosh

    CERN Multimedia

    1991-01-01

    System 7 is a single-user graphical user interface-based operating system for Macintosh computers and was part of the classic Mac OS line of operating systems. It was introduced on May 13, 1991, by Apple Computer. It succeeded System 6, and was the main Macintosh operating system until it was succeeded by Mac OS 8 in 1997. Features added with the System 7 release included virtual memory, personal file sharing, QuickTime, QuickDraw 3D, and an improved user interface. This is the first real major evolution of the Macintosh system, bringing a significant improvement in the user interface, improved stability and many new features such as the ability to use multiple applications at the same time. "System 7" is the last operating system name of the Macintosh that contains the word "system". Macintosh operating systems were later called "Mac OS" (for Macintosh Operating System).

  20. Software Systems Stockroom

    Science.gov (United States)

    2009-11-01

    44  Figure 28: The Triples Report PHP Source .................................................................................. 46  iii...relational database management system (RDBMS). The RDBMS chosen for the S3 prototype is MySQL [9] due to its particular suitability for fronting database...backed websites. However, any RDBMS compliant with the Drupal content management system is suitable. S3 is developed primarily in the PHP

  1. Clay club initiative: self-healing of fractures in clay-rich host rocks

    International Nuclear Information System (INIS)

    Horseman, S.T.; Cuss, R.J.; Reeves, H.J.

    2004-01-01

    The capacity of fractures in argillaceous rocks to self-heal (or become, with the passage of time, less conductive to groundwater) is often cited as a primary factor favouring the choice of such materials as host rocks for deep disposal. The underlying processes which contribute to self-healing can be broadly subdivided into: (a) mechanical and hydro-mechanical processes linked to the change in the stress field, movement of pore water, swelling, softening, plastic deformation and creep, and (b) geochemical processes linked to chemical alterations, transport in aqueous solution and the precipitation of minerals. Since chemical alteration can cause profound changes to the mechanical properties of argillaceous rocks, it is often difficult to draw a firm line between these two subdivisions. Based on the deliberations of the recent Cluster Conference in Luxembourg, there would appear to be some support for the use of the term 'self-sealing' for processes affecting fracture conductivity in argillaceous rock that are largely mechanical or hydro-mechanical in their origin. There are four main areas in which the self-healing capacity of the host rock becomes relevant to repository design and performance assessment: - potential for radionuclide transport within the excavation damage zone (EDZ); - design and performance of repository sealing systems; - potential impact of gas migration; - long-term performance considering erosional unloading, seismicity and fault reactivation. The presence of an EDZ is acknowledged to be a particularly important issue in performance assessment. Interconnection of fractures in the EDZ could lead to the development of a preferential flow path extending along the emplacement holes, access tunnels and shafts of a repository towards overlying aquifers and the biosphere. In the preliminary French Safety Analyses, for example, the treatment of scenarios relating to early seal failure have highlighted the hydraulic role of the damaged zone as a

  2. The primary protection system software

    International Nuclear Information System (INIS)

    Tooley, P.A.

    1992-01-01

    This paper continues the detailed description of the Primary Protection System for Sizewell-B by providing an overview of design and implementation of the software, including the features of the design process which ensure that quality is delivered by the contractor. The Nuclear Electric software assessment activities are also described. The argument for the excellence of the software is made on the basis of a quality product delivered by the equipment supplier's design process, and the confirmation of this provided by the Nuclear Electric assessment process, which is as searching and complete an examination as is reasonably practicable to achieve. (author)

  3. Resilient Software Systems

    Science.gov (United States)

    2015-06-01

    and tools, called model-integrated computing ( MIC ) [3] relies on the use of domain-specific modeling languages for creating models of the system to be...hence giving reflective capabilities to it. We have followed the MIC method here: we designed a domain- specific modeling language for modeling...are produced one-off and not for the mass market , the scope for price reduction based on the market demands is non-existent. Processes to create

  4. SPINning parallel systems software

    International Nuclear Information System (INIS)

    Matlin, O.S.; Lusk, E.; McCune, W.

    2002-01-01

    We describe our experiences in using Spin to verify parts of the Multi Purpose Daemon (MPD) parallel process management system. MPD is a distributed collection of processes connected by Unix network sockets. MPD is dynamic processes and connections among them are created and destroyed as MPD is initialized, runs user processes, recovers from faults, and terminates. This dynamic nature is easily expressible in the Spin/Promela framework but poses performance and scalability challenges. We present here the results of expressing some of the parallel algorithms of MPD and executing both simulation and verification runs with Spin

  5. Self-Healing, High-Permittivity Silicone Dielectric Elastomer

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt; Yu, Liyun; Skov, Anne Ladegaard

    2016-01-01

    possesses high dielectric permittivity and consists of an interpenetrating polymer network of silicone elastomer and ionic silicone species that are cross-linked through proton exchange between amines and acids. The ionically cross-linked silicone provides self-healing properties after electrical breakdown...... or cuts made directly to the material due to the reassembly of the ionic bonds that are broken during damage. The dielectric elastomers presented in this paper pave the way to increased lifetimes and the ability of dielectric elastomers to survive millions of cycles in high-voltage conditions....

  6. Computer systems and software engineering

    Science.gov (United States)

    Mckay, Charles W.

    1988-01-01

    The High Technologies Laboratory (HTL) was established in the fall of 1982 at the University of Houston Clear Lake. Research conducted at the High Tech Lab is focused upon computer systems and software engineering. There is a strong emphasis on the interrelationship of these areas of technology and the United States' space program. In Jan. of 1987, NASA Headquarters announced the formation of its first research center dedicated to software engineering. Operated by the High Tech Lab, the Software Engineering Research Center (SERC) was formed at the University of Houston Clear Lake. The High Tech Lab/Software Engineering Research Center promotes cooperative research among government, industry, and academia to advance the edge-of-knowledge and the state-of-the-practice in key topics of computer systems and software engineering which are critical to NASA. The center also recommends appropriate actions, guidelines, standards, and policies to NASA in matters pertinent to the center's research. Results of the research conducted at the High Tech Lab/Software Engineering Research Center have given direction to many decisions made by NASA concerning the Space Station Program.

  7. Experimental research control software system

    International Nuclear Information System (INIS)

    Cohn, I A; Kovalenko, A G; Vystavkin, A N

    2014-01-01

    A software system, intended for automation of a small scale research, has been developed. The software allows one to control equipment, acquire and process data by means of simple scripts. The main purpose of that development is to increase experiment automation easiness, thus significantly reducing experimental setup automation efforts. In particular, minimal programming skills are required and supervisors have no reviewing troubles. Interactions between scripts and equipment are managed automatically, thus allowing to run multiple scripts simultaneously. Unlike well-known data acquisition commercial software systems, the control is performed by an imperative scripting language. This approach eases complex control and data acquisition algorithms implementation. A modular interface library performs interaction with external interfaces. While most widely used interfaces are already implemented, a simple framework is developed for fast implementations of new software and hardware interfaces. While the software is in continuous development with new features being implemented, it is already used in our laboratory for automation of a helium-3 cryostat control and data acquisition. The software is open source and distributed under Gnu Public License.

  8. Experimental research control software system

    Science.gov (United States)

    Cohn, I. A.; Kovalenko, A. G.; Vystavkin, A. N.

    2014-05-01

    A software system, intended for automation of a small scale research, has been developed. The software allows one to control equipment, acquire and process data by means of simple scripts. The main purpose of that development is to increase experiment automation easiness, thus significantly reducing experimental setup automation efforts. In particular, minimal programming skills are required and supervisors have no reviewing troubles. Interactions between scripts and equipment are managed automatically, thus allowing to run multiple scripts simultaneously. Unlike well-known data acquisition commercial software systems, the control is performed by an imperative scripting language. This approach eases complex control and data acquisition algorithms implementation. A modular interface library performs interaction with external interfaces. While most widely used interfaces are already implemented, a simple framework is developed for fast implementations of new software and hardware interfaces. While the software is in continuous development with new features being implemented, it is already used in our laboratory for automation of a helium-3 cryostat control and data acquisition. The software is open source and distributed under Gnu Public License.

  9. Virtual Exercise Training Software System

    Science.gov (United States)

    Vu, L.; Kim, H.; Benson, E.; Amonette, W. E.; Barrera, J.; Perera, J.; Rajulu, S.; Hanson, A.

    2018-01-01

    The purpose of this study was to develop and evaluate a virtual exercise training software system (VETSS) capable of providing real-time instruction and exercise feedback during exploration missions. A resistive exercise instructional system was developed using a Microsoft Kinect depth-camera device, which provides markerless 3-D whole-body motion capture at a small form factor and minimal setup effort. It was hypothesized that subjects using the newly developed instructional software tool would perform the deadlift exercise with more optimal kinematics and consistent technique than those without the instructional software. Following a comprehensive evaluation in the laboratory, the system was deployed for testing and refinement in the NASA Extreme Environment Mission Operations (NEEMO) analog.

  10. Electrosprayed Multi-Core Alginate Microcapsules as Novel Self-Healing Containers.

    Science.gov (United States)

    Hia, Iee Lee; Pasbakhsh, Pooria; Chan, Eng-Seng; Chai, Siang-Piao

    2016-10-03

    Alginate microcapsules containing epoxy resin were developed through electrospraying method and embedded into epoxy matrix to produce a capsule-based self-healing composite system. These formaldehyde free alginate/epoxy microcapsules were characterized via light microscope, field emission scanning electron microscope, fourier transform infrared spectroscopy and thermogravimetric analysis. Results showed that epoxy resin was successfully encapsulated within alginate matrix to form porous (multi-core) microcapsules with pore size ranged from 5-100 μm. The microcapsules had an average size of 320 ± 20 μm with decomposition temperature at 220 °C. The loading capacity of these capsules was estimated to be 79%. Under in situ healing test, impact specimens showed healing efficiency as high as 86% and the ability to heal up to 3 times due to the multi-core capsule structure and the high impact energy test that triggered the released of epoxy especially in the second and third healings. TDCB specimens showed one-time healing only with the highest healing efficiency of 76%. The single healing event was attributed by the constant crack propagation rate of TDCB fracture test. For the first time, a cost effective, environmentally benign and sustainable capsule-based self-healing system with multiple healing capabilities and high healing performance was developed.

  11. Self-healing of Bessel-like beams with longitudinally dependent cone angles

    International Nuclear Information System (INIS)

    Litvin, I; Burger, L; Forbes, A

    2015-01-01

    Bessel beams have been extensively studied, but to date have been created over a finite region inside the laboratory. Recently Bessel-like beams with longitudinally dependent cone angles have been introduced allowing for a potentially infinite quasi non-diffracting propagation region. Here we show that such beams can self-heal. Moreover, in contrast to Bessel beams where the self-healing distance is constant, here the self-healing distance is dependent on where the obstruction is placed in the field, with the distance increasing as the Bessel-like beam propagates farther. We outline the theoretical concept for this self-healing and confirm it experimentally. (paper)

  12. Reusable self-healing hydrogels realized via in situ polymerization.

    Science.gov (United States)

    Vivek, Balachandran; Prasad, Edamana

    2015-04-09

    In this work, a self-healing hydrogel has been prepared using in situ polymerization of acrylic acid and acrylamide in the presence of glycogen. The hydrogel was characterized using NMR, SEM, FT-IR, rheology, and dynamic light scattering (DLS) studies. The developed hydrogel exhibits self-healing properties at neutral pH, high swelling ability, high elasticity, and excellent mechanical strength. The hydrogel exhibits modulus values (G', G″) as high as 10(6) Pa and shows an exceptionally high degree of swelling ratio (∼3.5 × 10(3)). Further, the polymer based hydrogel adsorbs toxic metal ions (Cd(2+), Pb(2+), and Hg(2+)) and organic dyes (methylene blue and methyl orange) from contaminated water with remarkable efficiency (90-98%). The mechanistic analysis indicated the presence of pseudo-second-order reaction kinetics. The reusability of the hydrogel has been demonstrated by repeating the adsorption-desorption process over five cycles with identical results in the adsorption efficiency.

  13. Processing and performance of self-healing materials

    International Nuclear Information System (INIS)

    Tan, P S; Bhattacharyya, D; Zhang, M Q

    2009-01-01

    Two self-healing methods were implemented into composite materials with self-healing capabilities, using hollow glass fibres (HGF) and microencapsulated epoxy resin with mercaptan as the hardener. For the HGF approach, two perpendicular layers of HGF were put into an E-glass/epoxy composite, and were filled with coloured epoxy resin and hardener. The HGF samples had a novel ball indentation test method done on them. The samples were analysed using micro-CT scanning, confocal microscopy and penetrant dye. Micro-CT and confocal microscopy produced limited success, but their viability was established. Penetrant dye images showed resin obstructing flow of dye through damage regions, suggesting infiltration of resin into cracks. Three-point bend tests showed that overall performance could be affected by the flaws arising from embedding HGF in the material. For the microcapsule approach, samples were prepared for novel double-torsion tests used to generate large cracks. The samples were compared with pure resin samples by analysing them using photoelastic imaging and scanning electron microscope (SEM) on crack surfaces. Photoelastic imaging established the consolidation of cracks while SEM showed a wide spread of microcapsules with their distribution being affected by gravity. Further double-torsion testing showed that healing recovered approximately 24% of material strength.

  14. Assessment of Composite Delamination Self-Healing Under Cyclic Loading

    Science.gov (United States)

    O'Brien, T. Kevin

    2009-01-01

    Recently, the promise of self-healing materials for enhanced autonomous durability has been introduced using a micro-encapsulation technique where a polymer based healing agent is encapsulated in thin walled spheres and embedded into a base polymer along with a catalyst phase. For this study, composite skin-stiffener flange debonding specimens were manufactured from composite prepreg containing interleaf layers with a polymer based healing agent encapsulated in thin-walled spheres. Constant amplitude fatigue tests in three-point bending showed the effect of self-healing on the fatigue response of the skin-stiffener flange coupons. After the cycling that created debonding, fatigue tests were held at the mean load for 24 hours. For roughly half the specimens tested, when the cyclic loading was resumed a decrease in compliance (increase in stiffness) was observed, indicating that some healing had occurred. However, with continued cycling, the specimen compliance eventually increased to the original level before the hold, indicating that the damage had returned to its original state. As was noted in a prevoius study conducted with specimens tested under monotonically increasing loads to failure, healing achieved via the micro-encapsulation technique may be limited to the volume of healing agent available relative to the crack volume.

  15. Packaging of control system software

    International Nuclear Information System (INIS)

    Zagar, K.; Kobal, M.; Saje, N.; Zagar, A.; Sabjan, R.; Di Maio, F.; Stepanov, D.

    2012-01-01

    Control system software consists of several parts - the core of the control system, drivers for integration of devices, configuration for user interfaces, alarm system, etc. Once the software is developed and configured, it must be installed to computers where it runs. Usually, it is installed on an operating system whose services it needs, and also in some cases dynamically links with the libraries it provides. Operating system can be quite complex itself - for example, a typical Linux distribution consists of several thousand packages. To manage this complexity, we have decided to rely on Red Hat Package Management system (RPM) to package control system software, and also ensure it is properly installed (i.e., that dependencies are also installed, and that scripts are run after installation if any additional actions need to be performed). As dozens of RPM packages need to be prepared, we are reducing the amount of effort and improving consistency between packages through a Maven-based infrastructure that assists in packaging (e.g., automated generation of RPM SPEC files, including automated identification of dependencies). So far, we have used it to package EPICS, Control System Studio (CSS) and several device drivers. We perform extensive testing on Red Hat Enterprise Linux 5.5, but we have also verified that packaging works on CentOS and Scientific Linux. In this article, we describe in greater detail the systematic system of packaging we are using, and its particular application for the ITER CODAC Core System. (authors)

  16. Self healing in polymers and polymer composites. Concepts, realization and outlook: A review

    Directory of Open Access Journals (Sweden)

    2008-04-01

    Full Text Available Formation of microcracks is a critical problem in polymers and polymer composites during their service in structural applications. Development and coalescence of microcracks would bring about catastrophic failure of the materials and then reduce their lifetimes. Therefore, early sensing, diagnosis and repair of microcracks become necessary for removing the latent perils. In this context, the materials possessing self-healing function are ideal for long-term operation. Self-repairing polymers and polymer composites have attracted increasing research interests. Attempts have been made to develop solutions in this field. The present article reviews state-of-art of the achievements on the topic. According to the ways of healing, the smart materials are classified into two categories: (i intrinsic self-healing ones that are able to heal cracks by the polymers themselves, and (ii extrinsic in which healing agent has to be pre-embedded. The advances in this field show that selection and optimization of proper repair mechanisms are prerequisites for high healing efficiency. It is a challenging job to either invent new polymers with inherent crack repair capability or integrate existing materials with novel healing system.

  17. Software for graphic display systems

    International Nuclear Information System (INIS)

    Karlov, A.A.

    1978-01-01

    In this paper some aspects of graphic display systems are discussed. The design of a display subroutine library is described, with an example, and graphic dialogue software is considered primarily from the point of view of the programmer who uses a high-level language. (Auth.)

  18. Software metrics: Software quality metrics for distributed systems. [reliability engineering

    Science.gov (United States)

    Post, J. V.

    1981-01-01

    Software quality metrics was extended to cover distributed computer systems. Emphasis is placed on studying embedded computer systems and on viewing them within a system life cycle. The hierarchy of quality factors, criteria, and metrics was maintained. New software quality factors were added, including survivability, expandability, and evolvability.

  19. Automating software design system DESTA

    Science.gov (United States)

    Lovitsky, Vladimir A.; Pearce, Patricia D.

    1992-01-01

    'DESTA' is the acronym for the Dialogue Evolutionary Synthesizer of Turnkey Algorithms by means of a natural language (Russian or English) functional specification of algorithms or software being developed. DESTA represents the computer-aided and/or automatic artificial intelligence 'forgiving' system which provides users with software tools support for algorithm and/or structured program development. The DESTA system is intended to provide support for the higher levels and earlier stages of engineering design of software in contrast to conventional Computer Aided Design (CAD) systems which provide low level tools for use at a stage when the major planning and structuring decisions have already been taken. DESTA is a knowledge-intensive system. The main features of the knowledge are procedures, functions, modules, operating system commands, batch files, their natural language specifications, and their interlinks. The specific domain for the DESTA system is a high level programming language like Turbo Pascal 6.0. The DESTA system is operational and runs on an IBM PC computer.

  20. The economics of information systems and software

    CERN Document Server

    Veryard, Richard

    2014-01-01

    The Economics of Information Systems and Software focuses on the economic aspects of information systems and software, including advertising, evaluation of information systems, and software maintenance. The book first elaborates on value and values, software business, and scientific information as an economic category. Discussions focus on information products and information services, special economic properties of information, culture and convergence, hardware and software products, materiality and consumption, technological progress, and software flexibility. The text then takes a look at a

  1. Certification of digital system software

    International Nuclear Information System (INIS)

    Waclo, J.; Cook, B.; Adomaitis, D.

    1991-01-01

    The activities involved in the successful application of digital systems to Nuclear Protection functions is not achieved through happenstance. At Westinghouse there has been a longstanding program to utilize digital state of the art technology for protection system advancement. Thereby gaining the advantages of increased system reliability, performance, ease of operation and reduced maintenance costs. This paper describes the Westinghouse background and experience in the safety system software development process, including Verification and Validation, and its application to protection system qualification and the successful use for licensing the Eagle 21 Digital Process Protection System Upgrade. In addition, the lessons learned from this experience are discussed from the perspective of improving the development process through applying feedback of the measurements made on the process and the software product quality. The goal of this process optimization is to produce the highest possible software quality while recognizing the real world constraints of available resources, project schedule and the regulatory policies that are customary in the nuclear industry

  2. Self-healing guar gum and guar gum-multiwalled carbon nanotubes nanocomposite gels prepared in an ionic liquid.

    Science.gov (United States)

    Sharma, Mukesh; Mondal, Dibyendu; Mukesh, Chandrakant; Prasad, Kamalesh

    2013-10-15

    Guar gum is a galactomannan extracted from the seed of the leguminous shrub Cyamopsis tetragonoloba. It was found to form a soft viscoelastic gel in 1-butyl-3-methylimidazolium chloride, an ionic liquid at an optimized concentration of 10%w/v. A nanocomposite gel of the gum with enhanced strength could be prepared with 0.2%w/v of multiwalled carbon nanotubes (MWCNTs) in the ionic liquid. When the gels thus prepared were subjected to surface fractures or bisected completely, they found to self-heal at room temperature without any external interventions. The self-healing process could be repeated several times. These viscoelastic gel systems showed thixotropic nature and recovery of the storage modulus with time for several cycles was observed upon rheological investigations. The interaction took place between ionic liquid, guar gum and MWCNT was studied by SEM, TEM, FT-IR, powder XRD and rheometry. The results suggested that, upon standing at room temperature development of electrostatic interactions and the van der Waals interactions among the ionic liquid molecules facilitated the formation of reversible noncovalent bonds and eventually activated the self-healing in the gel systems through appropriate chain entanglements. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Development of Micro and Nanostructured Materials for Interfacial Self-Healing

    Science.gov (United States)

    Blaiszik, Benjamin James

    2009-01-01

    Damage in polymeric coatings, adhesives, microelectronic components, and composites spans many length scales. For small scale damage, autonomic self-healing can repair multiple damage modes without manual intervention. In autonomic self-healing materials, a healing response is triggered by damage to the material. Size scale considerations, such as…

  4. Self healing phenomena in concretes and masonry mortars: A microscopic study

    NARCIS (Netherlands)

    Nijland, T.G.; Larbi, J.A.; Hees, R.P.J. van; Lubelli, B.A.; Rooij, M.R. de

    2007-01-01

    A microscopic survey of over 1000 of samples of concrete and masonry mortars from structures in the Netherlands shows that, in practice, self healing occurs in historic lime and lime – puzzolana mortars, in contrast to modern cement bound concretes and mortars. Self healing may be effected by the

  5. Novel approach to make concrete structures self-healing using porous network concrete

    NARCIS (Netherlands)

    Sangadji, S.; Schlangen, E.

    2012-01-01

    Many researchers proposed self healing mechanism using hollow fibres and or microcapsule containing a modifying agent dispersed in the concrete to prolong its service life and make it more durable. A novel self healing concrete concept is proposed in this paper by using porous network concrete

  6. Investigation of self healing behaviour of asphalt mixes using beam on elastic foundation setup

    NARCIS (Netherlands)

    Qiu, J.; Molenaar, A.A.A.; Van de Ven, M.F.C.; Wu, S.; Yu, J.

    2012-01-01

    Self healing of asphalt mixes is known for more than four decades. However, it is a complex phenomenon which depends on the duration of the rest period, temperature, crack size, etc. In order to quantify the self healing behaviour of asphalt mixes, a test setup was proposed in this research using an

  7. Effect of blast furnace slag on self-healing of microcracks in cementitious materials

    International Nuclear Information System (INIS)

    Huang, Haoliang; Ye, Guang; Damidot, Denis

    2014-01-01

    The physico-chemical process of self-healing in blast furnace slag cement paste was investigated in this paper. With a high slag content i.e., 66% in cement paste and saturated Ca(OH) 2 solution as activator, it was found that the reaction products formed in cracks are composed of C-S-H, ettringite, hydrogarnet and OH–hydrotalcite. The fraction of C-S-H in the reaction products is much larger than the other minerals. Large amount of ettringite formed in cracks indicates the leaching of SO 4 2− ions from the bulk paste and consequently the recrystallization. Self-healing proceeds fast within 50 h and then slows down. According to thermodynamic modeling, when the newly formed reaction products are carbonated, the filling fraction of crack increases first and then decreases. Low soluble minerals such as silica gel, gibbsite and calcite are formed. Compared to Portland cement paste, the potential of self-healing in slag cement paste is higher when the percentage of slag is high. - Highlights: • Self-healing reaction products in slag cement paste were characterized. • Self-healing reaction products formed in time were quantified with image analysis. • Self-healing in slag cement paste was simulated with a reactive transport model. • Effect of carbonation on self-healing was investigated by thermodynamic modeling. • Effect of slag on self-healing was discussed based on experiments and simulation

  8. Rheo-mechanical model for self-healing asphalt pavement

    International Nuclear Information System (INIS)

    Gömze, A L; Gömze, L N

    2017-01-01

    Examining the rheological properties of different asphalt mixtures at different temperatures, pressures and deformation conditions on the combined rheo-tribometers the authors have found that the generally used Burgers-model doesn’t explain the deformation properties of asphalt mixtures and pavements under loading forces and loading pressures. To understand better the rheological and deformation properties of such complex materials like asphalt mixtures and pavements the authors used Malvern Mastersizer X laser granulometer, Bruker D8 Advance X-ray diffractometer, Hitachi TM 1000 Scanning Elektronmicroscope, Tristar 3000 specific surface tester and the combined rheo-tribometer developed and patented by the authors. After the complex investigation of different asphalt mixtures the authors have found a new, more complex rheological model for the asphalts including self-healing asphalt pavements. (paper)

  9. Effect of temperature on surface error and laser damage threshold for self-healing BK7 glass.

    Science.gov (United States)

    Wang, Chu; Wang, Hongxiang; Shen, Lu; Hou, Jing; Xu, Qiao; Wang, Jian; Chen, Xianhua; Liu, Zhichao

    2018-03-20

    Cracks caused during the lapping and polishing process can decrease the laser-induced damage threshold (LIDT) of the BK7 glass optical elements, which would shorten the lifetime and limit the output power of the high-energy laser system. When BK7 glass is heated under appropriate conditions, the surface cracks can exhibit a self-healing phenomenon. In this paper, based on thermodynamics and viscous fluid mechanics theory, the mechanisms of crack self-healing are explained. The heat-healing experiment was carried out, and the effect of water was analyzed. The multi-spatial-frequency analysis was used to investigate the effect of temperature on surface error for self-healing BK7 glass, and the lapped BK7 glass specimens before and after heat healing were detected by an interferometer and atomic force microscopy. The low-spatial-frequency error was analyzed by peak to valley and root mean square, the mid-spatial-frequency error was analyzed by power spectral density, and the high-spatial-frequency error was analyzed by surface roughness. The results showed that the optimal heating temperature for BK7 was 450°C, and when the heating temperature was higher than the glass transition temperature (555°C), the surface quality decreased a lot. The laser damage test was performed, and the specimen heated at 450°C showed an improvement in LIDT.

  10. Surface self-organization: From wear to self-healing in biological and technical surfaces

    International Nuclear Information System (INIS)

    Nosonovsky, Michael; Bhushan, Bharat

    2010-01-01

    Wear occurs at most solid surfaces that come in contact with other solid surfaces. While biological surfaces and tissues usually have the ability for self-healing, engineered self-healing materials only started to emerge recently. These materials are currently created using the trial-and-error approach and phenomenological models, so there is a need of a general first-principles theory of self-healing. We discuss the conditions under which the self-healing occurs and provide a general theoretical framework and criteria for self-healing using the concept of multiscale organization of entropy and non-equilibrium thermodynamics. The example of epicuticular wax regeneration of plant leaves is discussed as a case study.

  11. A Survey on Smart Agent-Based Microgrids for Resilient/Self-Healing Grids

    Directory of Open Access Journals (Sweden)

    Kaveh Dehghanpour

    2017-05-01

    Full Text Available This paper presents an overview of our body of work on the application of smart control techniques for the control and management of microgrids (MGs. The main focus here is on the application of distributed multi-agent system (MAS theory in multi-objective (MO power management of MGs to find the Pareto-front of the MO power management problem. In addition, the paper presents the application of Nash bargaining solution (NBS and the MAS theory to directly obtain the NBS on the Pareto-front. The paper also discusses the progress reported on the above issues from the literature. We also present a MG-based power system architecture for enhancing the resilience and self-healing of the system.

  12. Robust, Self-Healing Superhydrophobic Fabrics Prepared by One-Step Coating of PDMS and Octadecylamine

    Science.gov (United States)

    Xue, Chao-Hua; Bai, Xue; Jia, Shun-Tian

    2016-01-01

    A robust, self-healing superhydrophobic poly(ethylene terephthalate) (PET) fabric was fabricated by a convenient solution-dipping method using an easily available material system consisting of polydimethylsiloxane and octadecylamine (ODA). The surface roughness was formed by self-roughening of ODA coating on PET fibers without any lithography steps or adding any nanomaterials. The fabric coating was durable to withstand 120 cycles of laundry and 5000 cycles of abrasion without apparently changing the superhydrophobicity. More interestingly, the fabric can restore its super liquid-repellent property by 72 h at room temperature even after 20000 cycles of abrasion. Meanwhile, after being damaged chemically, the fabric can restore its superhydrophobicity automatically in 12 h at room temperature or by a short-time heating treatment. We envision that this simple but effective coating system may lead to the development of robust protective clothing for various applications. PMID:27264995

  13. eDNA: A Bio-Inspired Reconfigurable Hardware Cell Architecture Supporting Self-organisation and Self-healing

    DEFF Research Database (Denmark)

    Boesen, Michael Reibel; Madsen, Jan

    2009-01-01

    This paper presents the concept of a biological inspired reconfigurable hardware cell architecture which supports self-organisation and self-healing. Two fundamental processes in biology, namely fertilization-to-birth and cell self-healing have inspired the development of this cell architecture...... to simulate our self-organisation and self-healing algorithms and the results obtained from this looks promising....

  14. A cost-effective bacteria-based self-healing cementitious composite for low-temperature marine applications

    NARCIS (Netherlands)

    Palin, D.

    2017-01-01

    Bacteria-based self-healing concrete is an innovative self-healing materials approach, whereby bacteria embedded in concrete can form a crack healing mineral precipitate. Structures made from self-healing concrete promise longer service lives, with associated economic benefits [1]. Despite concretes

  15. Degradation failure model of self-healing metallized film pulse capacitor

    International Nuclear Information System (INIS)

    Sun Quan; Zhong Zheng; Zhou Jinglun; Zhao Jianyin; Wei Xiaofeng; Guo Liangfu; Zhou Pizhang; Li Yizheng; Chen Dehuai

    2004-01-01

    The high energy density self-healing metallized film pulse capacitor has been applied to all kinds of laser facilities for their power conditioning systems, whose reliability and expense are straightforwardly affected by the reliability level of the capacitors. Based on the related research in literature, this paper analyses the degradation mechanism of the capacitor, and presents a new degradation failure model--the Gauss-Poisson model. The Gauss-Poisson model divides degradation of capacitor into naturalness degradation and outburst one. Compared with traditional Weibull failure model, the new model is more precise in evaluating the lifetime of the capacitor, and the life tests for this model are simple in design, and lower in the cost of time or expense. The Gauss-Poisson model will be a fine and widely used degradation disable model. (author)

  16. High Confidence Software and Systems Research Needs

    Data.gov (United States)

    Networking and Information Technology Research and Development, Executive Office of the President — This White Paper presents a survey of high confidence software and systems research needs. It has been prepared by the High Confidence Software and Systems...

  17. Research of the self-healing technologies in the optical communication network of distribution automation

    Science.gov (United States)

    Wang, Hao; Zhong, Guoxin

    2018-03-01

    Optical communication network is the mainstream technique of the communication networks for distribution automation, and self-healing technologies can improve the in reliability of the optical communication networks significantly. This paper discussed the technical characteristics and application scenarios of several network self-healing technologies in the access layer, the backbone layer and the core layer of the optical communication networks for distribution automation. On the base of the contrastive analysis, this paper gives an application suggestion of these self-healing technologies.

  18. Space Flight Software Development Software for Intelligent System Health Management

    Science.gov (United States)

    Trevino, Luis C.; Crumbley, Tim

    2004-01-01

    The slide presentation examines the Marshall Space Flight Center Flight Software Branch, including software development projects, mission critical space flight software development, software technical insight, advanced software development technologies, and continuous improvement in the software development processes and methods.

  19. Software And Systems Engineering Risk Management

    Science.gov (United States)

    2010-04-01

    RSKM 2004 COSO Enterprise RSKM Framework 2006 ISO/IEC 16085 Risk Management Process 2008 ISO/IEC 12207 Software Lifecycle Processes 2009 ISO/IEC...1 Software And Systems Engineering Risk Management John Walz VP Technical and Conferences Activities, IEEE Computer Society Vice-Chair Planning...Software & Systems Engineering Standards Committee, IEEE Computer Society US TAG to ISO TMB Risk Management Working Group Systems and Software

  20. Fundamental Solution For The Self-healing Fracture Pulse

    Science.gov (United States)

    Nielsen, S.; Madariaga, R.

    We find the analytical solution for a fundamental fracture mode in the form of a self- similar, self-healing pulse. The existence of such a fracture mode was strongly sug- gested by recent numerical findings but, to our knwledge, no formal proof had been proposed up to date. We present a two dimensional, anti-plane solution for fixed rup- ture and healing velocities, that satisfies both wave equation and stress conditions; we argue that such a solution is plausible even in the absence of rate-weakening in the friction, as an alternative to the classic crack solution. In practice, the impulsive mode rather than the expanding crack mode is selected depending on details of fracture initiation, and is therafter self-maintained. We discuss stress concentration, fracture energy, rupture velocity and compare them to the case of a crack. The analytical study is complemented by various numerical examples and comparisons. On more general grounds, we argue that an infinity of marginally stable fracture modes may exist other than the crack solution or the impulseive fracture described here.

  1. Software Quality Assurance for Nuclear Safety Systems

    International Nuclear Information System (INIS)

    Sparkman, D R; Lagdon, R

    2004-01-01

    The US Department of Energy has undertaken an initiative to improve the quality of software used to design and operate their nuclear facilities across the United States. One aspect of this initiative is to revise or create new directives and guides associated with quality practices for the safety software in its nuclear facilities. Safety software includes the safety structures, systems, and components software and firmware, support software and design and analysis software used to ensure the safety of the facility. DOE nuclear facilities are unique when compared to commercial nuclear or other industrial activities in terms of the types and quantities of hazards that must be controlled to protect workers, public and the environment. Because of these differences, DOE must develop an approach to software quality assurance that ensures appropriate risk mitigation by developing a framework of requirements that accomplishes the following goals: (sm b ullet) Ensures the software processes developed to address nuclear safety in design, operation, construction and maintenance of its facilities are safe (sm b ullet) Considers the larger system that uses the software and its impacts (sm b ullet) Ensures that the software failures do not create unsafe conditions Software designers for nuclear systems and processes must reduce risks in software applications by incorporating processes that recognize, detect, and mitigate software failure in safety related systems. It must also ensure that fail safe modes and component testing are incorporated into software design. For nuclear facilities, the consideration of risk is not necessarily sufficient to ensure safety. Systematic evaluation, independent verification and system safety analysis must be considered for software design, implementation, and operation. The software industry primarily uses risk analysis to determine the appropriate level of rigor applied to software practices. This risk-based approach distinguishes safety

  2. Software for nuclear data acquisition systems

    International Nuclear Information System (INIS)

    Christensen, P.

    1983-01-01

    The situation for experimenters and system designers needing software for instrumentation is described. It is stated that software for a data acquisition system can be divided into programmes described as the foundation software, the applications programme, and the analysis programme. Special attention is given to CAMAC. Two examples from Risoe describing data transportation and archiving are given. Finally the supply of software and the problems of documentation are described. (author)

  3. Methyl methacrylate as a healing agent for self-healing cementitious materials

    International Nuclear Information System (INIS)

    Van Tittelboom, K; De Belie, N; Adesanya, K; Dubruel, P; Van Puyvelde, P

    2011-01-01

    Different types of healing agents have already been tested on their efficiency for use in self-healing cementitious materials. Generally, commercial healing agents are used while their properties are adjusted for manual crack repair and not for autonomous crack healing. Consequently, the amount of regain in properties due to self-healing of cracks is limited. In this research, a methyl methacrylate (MMA)-based healing agent was developed specifically for use in self-healing cementitious materials. Various parameters were optimized including the viscosity, curing time, strength, etc. After the desired properties were obtained, the healing agent was encapsulated and screened for its self-healing efficiency. The decrease in water permeability due to autonomous crack healing using MMA as a healing agent was similar to the results obtained for manually healed cracks. First results seem promising: however, further research needs to be undertaken in order to obtain an optimal healing agent ready for use in practice

  4. Multifunctional Shielding and Self-Healing HybridSil Smart Composites for Space, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NanoSonic has developed revolutionary multifunctional, super lightweight, self-healing and radiation shielding carbon fiber reinforced polymer (CFRP) composites as a...

  5. Analytical study on the self-healing property of Bessel beam

    Science.gov (United States)

    Chu, X.

    2012-10-01

    With the help of Babinet principle, an analytical expression for the self-healing of Bessel beam is derived by using the Gaussian absorption function to describe the obstacle. Based on the analytical expression, the self-healing properties of Bessel beam are studied. It shows that Bessel beam has the ability to reconstruct its beam shape disturbed by an obstacle. However, during the self-healing process, not only the intensity of the beam behind the obstacle but also the other part will be affected by the obstruction. Meanwhile, the highlight spot, which intensity is larger than that without the obstacle will appear, and the size and strength of the highlight spot is determined by the size of the obstacle. From the change of Poynting vector and Babinet principle, the physical interpretations for the self-healing ability, the effects of the obstruction on the other part and the appearance of highlight spot are given.

  6. Management information systems software evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Al-Tunisi, N.; Ghazzawi, A.; Gruyaert, F.; Clarke, D. [Saudi Aramco, Dhahran (Saudi Arabia). Process and Control Systems Dept.

    1995-11-01

    In November 1993, Saudi Aramco management endorsed a proposal to coordinate the development of the Management Information Systems (MISs) of four concurrent projects for its facilities Controls Modernization Program. The affected projects were the Ras Tanura Refinery Upgrade Project, the Abqaiq Plant Controls Modernization and the Shedgum and Uthmaniyah Gas plants Control Upgrade Projects. All of these projects had a significant requirement of MISs in their scope. Under the leadership of the Process and Control Systems Department, and MIS Coordination Team was formed with representatives of several departments. An MIS Applications Evaluation procedure was developed based on the Kepner Tregoe Decisions Analysis Process and general questionnaires were sent to over a hundred potential Vendors. The applications were divided into several categories, such as: Data Capture and Historization, Human User Interface, Trending, Reporting, Graphic Displays, Data Reconciliation, Statistical Analysis, Expert Systems, Maintenance Applications, Document Management and Operations Planning and Scheduling. For each of the MIS Application areas, detailed follow-up questionnaires were used to short list the candidate products. In May and June 1994, selected Vendors were invited to Saudi Arabia for an Exhibition which was open to all Saudi Aramco employees. In conjunction with this, the Vendors were subjected to a rigorous product testing exercise by independent teams of testers. The paper will describe the methods used and the lessons learned in this extensive software evaluation phase, which was a first for Saudi Aramco.

  7. Management information systems software evaluation

    International Nuclear Information System (INIS)

    Al-Tunisi, N.; Ghazzawi, A.; Gruyaert, F.; Clarke, D.

    1995-01-01

    In November 1993, Saudi Aramco management endorsed a proposal to coordinate the development of the Management Information Systems (MISs) of four concurrent projects for its facilities Controls Modernization Program. The affected projects were the Ras Tanura Refinery Upgrade Project, the Abqaiq Plant Controls Modernization and the Shedgum and Uthmaniyah Gas plants Control Upgrade Projects. All of these projects had a significant requirement of MISs in their scope. Under the leadership of the Process and Control Systems Department, and MIS Coordination Team was formed with representatives of several departments. An MIS Applications Evaluation procedure was developed based on the Kepner Tregoe Decisions Analysis Process and general questionnaires were sent to over a hundred potential Vendors. The applications were divided into several categories, such as: Data Capture and Historization, Human User Interface, Trending, Reporting, Graphic Displays, Data Reconciliation, Statistical Analysis, Expert Systems, Maintenance Applications, Document Management and Operations Planning and Scheduling. For each of the MIS Application areas, detailed follow-up questionnaires were used to short list the candidate products. In May and June 1994, selected Vendors were invited to Saudi Arabia for an Exhibition which was open to all Saudi Aramco employees. In conjunction with this, the Vendors were subjected to a rigorous product testing exercise by independent teams of testers. The paper will describe the methods used and the lessons learned in this extensive software evaluation phase, which was a first for Saudi Aramco

  8. Synthesis of a new hardener agent for self-healing epoxy resins

    Science.gov (United States)

    Raimondo, Marialuigia; Guadagno, Liberata; Naddeo, Carlo; Longo, Pasquale; Mariconda, Annaluisa; Agovino, Anna

    2014-05-01

    Actually, the development of smart composites capable of self-repair in aeronautical structures is still at the planning stage owing to complex issues to overcome. One of the critical points in the development of self-healing epoxy resin is related to the impossibility to employ primary amines as hardeners. In this paper, the synthesis of a new hardener for self-healing resins is shown together with applicability conditions/ranges.

  9. Electrical and Structural Origin of Self-Healing Phenomena in Pentacene Thin Films.

    Science.gov (United States)

    Kang, Evan S H; Zhang, Hongbin; Donner, Wolfgang; von Seggern, Heinz

    2017-04-01

    Self-healing induced by structural phase transformation is demonstrated using pentacene field-effect transistors. During the self-healing process, the electrical properties at the pentacene interfaces improve due to the phase transformation from monolayer phase to thin-film phase. Enhanced mobility is confirmed by first-principles calculations. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Test software for BESIII MDC electronics system

    International Nuclear Information System (INIS)

    Zhang Hongyu; Sheng Huayi; Zhu Haitao; Ji Xiaolu; Zhao Dongxu

    2006-01-01

    This paper presents the design of Test System Software for BESIII MDC Electronics. Two kinds of test systems, SBS VP7 based and PowerPC based systems, and their corresponding test software are introduced. The software is developed in LabVIEW 7.1 and Microsoft Visual C++ 6.0, some test functions of the software, as well as their user interfaces, are described in detail. The software has been applied in hardware debugging, performance test and long term stability test. (authors)

  11. Self-Healing Textile: Enzyme Encapsulated Layer-by-Layer Structural Proteins.

    Science.gov (United States)

    Gaddes, David; Jung, Huihun; Pena-Francesch, Abdon; Dion, Genevieve; Tadigadapa, Srinivas; Dressick, Walter J; Demirel, Melik C

    2016-08-10

    Self-healing materials, which enable an autonomous repair response to damage, are highly desirable for the long-term reliability of woven or nonwoven textiles. Polyelectrolyte layer-by-layer (LbL) films are of considerable interest as self-healing coatings due to the mobility of the components comprising the film. In this work mechanically stable self-healing films were fabricated through construction of a polyelectrolyte LbL film containing squid ring teeth (SRT) proteins. SRTs are structural proteins with unique self-healing properties and high elastic modulus in both dry and wet conditions (>2 GPa) due to their semicrystalline architecture. We demonstrate LbL construction of multilayers containing native and recombinant SRT proteins capable of self-healing defects. Additionally, we show these films are capable of utilizing functional biomolecules by incorporating an enzyme into the SRT multilayer. Urease was chosen as a model enzyme of interest to test its activity via fluorescence assay. Successful construction of the SRT films demonstrates the use of mechanically stable self-healing coatings, which can incorporate biomolecules for more complex protective functionalities for advanced functional fabrics.

  12. Lap shear strength and healing capability of self-healing adhesive containing epoxy/mercaptan microcapsules

    Energy Technology Data Exchange (ETDEWEB)

    Ghazali, Habibah; Ye, Lin [Centre for Advanced Materials Technology (CAMT), School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006 (Australia); Zhang, Ming-Qiu [Key Laboratory of Polymeric Composite and Functional Materials of Ministry of Education, Zhongshan University, Guangzhou 510275 (China)

    2016-03-09

    The aim of this work is to develop a self-healing polymeric adhesive formulation with epoxy/mercaptan microcapsules. Epoxy/mercaptan microcapsules were dispersed into a commercialize two-part epoxy adhesive for developing self-healing epoxy adhesive. The influence of different content of microcapsules on the shear strength and healing capability of epoxy adhesive were investigated using single-lap-joints with average thickness of adhesive layer of about 180 µm. This self-healing adhesive was used in bonding of 5000 series aluminum alloys adherents after mechanical and alkaline cleaning surface treatment. The adhesion strength was measured and presented as function of microcapsules loading. The results indicated that the virgin lap shear strength was increased by about 26% with addition of 3 wt% of self-healing microcapsules. 12% to 28% recovery of the shear strength is achieved after self-healing depending on the microcapsules content. Scanning electron microscopy was used to study fracture surface of the joints. The self-healing adhesives exhibit recovery of both cohesion and adhesion properties with room temperature healing.

  13. Lap shear strength and healing capability of self-healing adhesive containing epoxy/mercaptan microcapsules

    International Nuclear Information System (INIS)

    Ghazali, Habibah; Ye, Lin; Zhang, Ming-Qiu

    2016-01-01

    The aim of this work is to develop a self-healing polymeric adhesive formulation with epoxy/mercaptan microcapsules. Epoxy/mercaptan microcapsules were dispersed into a commercialize two-part epoxy adhesive for developing self-healing epoxy adhesive. The influence of different content of microcapsules on the shear strength and healing capability of epoxy adhesive were investigated using single-lap-joints with average thickness of adhesive layer of about 180 µm. This self-healing adhesive was used in bonding of 5000 series aluminum alloys adherents after mechanical and alkaline cleaning surface treatment. The adhesion strength was measured and presented as function of microcapsules loading. The results indicated that the virgin lap shear strength was increased by about 26% with addition of 3 wt% of self-healing microcapsules. 12% to 28% recovery of the shear strength is achieved after self-healing depending on the microcapsules content. Scanning electron microscopy was used to study fracture surface of the joints. The self-healing adhesives exhibit recovery of both cohesion and adhesion properties with room temperature healing.

  14. Software dependability in the Tandem GUARDIAN system

    Science.gov (United States)

    Lee, Inhwan; Iyer, Ravishankar K.

    1995-01-01

    Based on extensive field failure data for Tandem's GUARDIAN operating system this paper discusses evaluation of the dependability of operational software. Software faults considered are major defects that result in processor failures and invoke backup processes to take over. The paper categorizes the underlying causes of software failures and evaluates the effectiveness of the process pair technique in tolerating software faults. A model to describe the impact of software faults on the reliability of an overall system is proposed. The model is used to evaluate the significance of key factors that determine software dependability and to identify areas for improvement. An analysis of the data shows that about 77% of processor failures that are initially considered due to software are confirmed as software problems. The analysis shows that the use of process pairs to provide checkpointing and restart (originally intended for tolerating hardware faults) allows the system to tolerate about 75% of reported software faults that result in processor failures. The loose coupling between processors, which results in the backup execution (the processor state and the sequence of events) being different from the original execution, is a major reason for the measured software fault tolerance. Over two-thirds (72%) of measured software failures are recurrences of previously reported faults. Modeling, based on the data, shows that, in addition to reducing the number of software faults, software dependability can be enhanced by reducing the recurrence rate.

  15. Space Telescope Pointing Control System software

    Science.gov (United States)

    Dougherty, H.; Rodoni, C.; Rossini, R.; Tompetrini, K.; Nakashima, A.; Bradley, A.

    1982-01-01

    The Space Telescope Pointing Control System software is in the advanced development stage, having been tested on both the airbearing and the static simulator. The overall structure of the software is discussed, along with timing and sizing evaluations. The interaction between the controls analysts and software designer is described.

  16. Honeywell Modular Automation System Computer Software Documentation

    International Nuclear Information System (INIS)

    STUBBS, A.M.

    2000-01-01

    The purpose of this Computer Software Document (CSWD) is to provide configuration control of the Honeywell Modular Automation System (MAS) in use at the Plutonium Finishing Plant (PFP). This CSWD describes hardware and PFP developed software for control of stabilization furnaces. The Honeywell software can generate configuration reports for the developed control software. These reports are described in the following section and are attached as addendum's. This plan applies to PFP Engineering Manager, Thermal Stabilization Cognizant Engineers, and the Shift Technical Advisors responsible for the Honeywell MAS software/hardware and administration of the Honeywell System

  17. A Software Development Platform for Mechatronic Systems

    DEFF Research Database (Denmark)

    Guan, Wei

    Software has become increasingly determinative for development of mechatronic systems, which underscores the importance of demands for shortened time-to-market, increased productivity, higher quality, and improved dependability. As the complexity of systems is dramatically increasing, these demands...... present a challenge to the practitioners who adopt conventional software development approach. An effective approach towards industrial production of software for mechatronic systems is needed. This approach requires a disciplined engineering process that encompasses model-driven engineering and component......-based software engineering, whereby we enable incremental software development using component models to address the essential design issues of real-time embedded systems. To this end, this dissertation presents a software development platform that provides an incremental model-driven development process based...

  18. A NEW EXHAUST VENTILATION SYSTEM DESIGN SOFTWARE

    Directory of Open Access Journals (Sweden)

    H. Asilian Mahabady

    2007-09-01

    Full Text Available A Microsoft Windows based ventilation software package is developed to reduce time-consuming and boring procedure of exhaust ventilation system design. This program Assure accurate and reliable air pollution control related calculations. Herein, package is tentatively named Exhaust Ventilation Design Software which is developed in VB6 programming environment. Most important features of Exhaust Ventilation Design Software that are ignored in formerly developed packages are Collector design and fan dimension data calculations. Automatic system balance is another feature of this package. Exhaust Ventilation Design Software algorithm for design is based on two methods: Balance by design (Static pressure balance and design by Blast gate. The most important section of software is a spreadsheet that is designed based on American Conference of Governmental Industrial Hygienists calculation sheets. Exhaust Ventilation Design Software is developed so that engineers familiar with American Conference of Governmental Industrial Hygienists datasheet can easily employ it for ventilation systems design. Other sections include Collector design section (settling chamber, cyclone, and packed tower, fan geometry and dimension data section, a unit converter section (that helps engineers to deal with units, a hood design section and a Persian HTML help. Psychometric correction is also considered in Exhaust Ventilation Design Software. In Exhaust Ventilation Design Software design process, efforts are focused on improving GUI (graphical user interface and use of programming standards in software design. Reliability of software has been evaluated and results show acceptable accuracy.

  19. Software for Embedded Control Systems

    NARCIS (Netherlands)

    Broenink, Johannes F.; Hilderink, G.H.; Jovanovic, D.S.

    2001-01-01

    The research of our team deals with the realization of control schemes on digital computers. As such the emphasis is on embedded control software implementation. Applications are in the field of mechatronic devices, using a mechatronic design approach (the integrated and optimal design of a

  20. Tools for Embedded Computing Systems Software

    Science.gov (United States)

    1978-01-01

    A workshop was held to assess the state of tools for embedded systems software and to determine directions for tool development. A synopsis of the talk and the key figures of each workshop presentation, together with chairmen summaries, are presented. The presentations covered four major areas: (1) tools and the software environment (development and testing); (2) tools and software requirements, design, and specification; (3) tools and language processors; and (4) tools and verification and validation (analysis and testing). The utility and contribution of existing tools and research results for the development and testing of embedded computing systems software are described and assessed.

  1. Expert System Software Assistant for Payload Operations

    Science.gov (United States)

    Rogers, Mark N.

    1997-01-01

    The broad objective of this expert system software based application was to demonstrate the enhancements and cost savings that can be achieved through expert system software utilization in a spacecraft ground control center. Spacelab provided a valuable proving ground for this advanced software technology; a technology that will be exploited and expanded for future ISS operations. Our specific focus was on demonstrating payload cadre command and control efficiency improvements through the use of "smart" software which monitors flight telemetry, provides enhanced schematic-based data visualization, and performs advanced engineering data analysis.

  2. An overview on the research on self-healing concrete at Politecnico di Milano

    Directory of Open Access Journals (Sweden)

    Ferrara Liberato

    2017-01-01

    Full Text Available Self-healing cement based materials, by controlling and repairing cracks, could prevent “permeation of driving factors for deterioration”, thus extending the structure service life, and even provide partial recovery of engineering properties relevant to the application. The author’s group has undertaken a comprehensive investigation focusing on both experimental characterization and numerical modelling of the self-healing capacity of a broad category of cementitious composites, including high performance cementitious composites reinforced with different kinds of fibres. Both autogenous healing has been considered and self-healing engineered techniques, including the use of pre-saturated natural fibres and of crystalline admixtures. Tailored methodologies have been employed to characterize the healing capacity under different exposure conditions and for different time spans, ranging up to two years. The healing capacity has been quantified by means of suitably defined “healing indices”, based on the recovery of mechanical properties correlated to the amount of crack closure, measured by means of optical microscopy. A predictive modelling approach, based on modified micro-plane model, has been formulated. The whole investigation represents a step towards the reliable and consistent incorporation of self-healing concepts and effects into a durability-based design framework for engineering applications made of or retrofitted with self- healing concrete and cementitious composites.

  3. Honeywell modular automation system computer software documentation

    International Nuclear Information System (INIS)

    Cunningham, L.T.

    1997-01-01

    This document provides a Computer Software Documentation for a new Honeywell Modular Automation System (MAS) being installed in the Plutonium Finishing Plant (PFP). This system will be used to control new thermal stabilization furnaces in HA-21I

  4. Achieving Critical System Survivability Through Software Architectures

    National Research Council Canada - National Science Library

    Knight, John C; Strunk, Elisabeth A

    2006-01-01

    .... In a system with a survivability architecture, under adverse conditions such as system damage or software failures, some desirable function will be eliminated but critical services will be retained...

  5. Gas characterization system software acceptance test procedure

    International Nuclear Information System (INIS)

    Vo, C.V.

    1996-01-01

    This document details the Software Acceptance Testing of gas characterization systems. The gas characterization systems will be used to monitor the vapor spaces of waste tanks known to contain measurable concentrations of flammable gases

  6. Gas characterization system software acceptance test report

    International Nuclear Information System (INIS)

    Vo, C.V.

    1996-01-01

    This document details the results of software acceptance testing of gas characterization systems. The gas characterization systems will be used to monitor the vapor spaces of waste tanks known to contain measurable concentrations of flammable gases

  7. Software Reliability Issues Concerning Large and Safety Critical Software Systems

    Science.gov (United States)

    Kamel, Khaled; Brown, Barbara

    1996-01-01

    This research was undertaken to provide NASA with a survey of state-of-the-art techniques using in industrial and academia to provide safe, reliable, and maintainable software to drive large systems. Such systems must match the complexity and strict safety requirements of NASA's shuttle system. In particular, the Launch Processing System (LPS) is being considered for replacement. The LPS is responsible for monitoring and commanding the shuttle during test, repair, and launch phases. NASA built this system in the 1970's using mostly hardware techniques to provide for increased reliability, but it did so often using custom-built equipment, which has not been able to keep up with current technologies. This report surveys the major techniques used in industry and academia to ensure reliability in large and critical computer systems.

  8. Software engineering practices for control system reliability

    International Nuclear Information System (INIS)

    S. K. Schaffner; K. S White

    1999-01-01

    This paper will discuss software engineering practices used to improve Control System reliability. The authors begin with a brief discussion of the Software Engineering Institute's Capability Maturity Model (CMM) which is a framework for evaluating and improving key practices used to enhance software development and maintenance capabilities. The software engineering processes developed and used by the Controls Group at the Thomas Jefferson National Accelerator Facility (Jefferson Lab), using the Experimental Physics and Industrial Control System (EPICS) for accelerator control, are described. Examples are given of how their procedures have been used to minimized control system downtime and improve reliability. While their examples are primarily drawn from their experience with EPICS, these practices are equally applicable to any control system. Specific issues addressed include resource allocation, developing reliable software lifecycle processes and risk management

  9. Requirements engineering for software and systems

    CERN Document Server

    Laplante, Phillip A

    2014-01-01

    Solid requirements engineering has increasingly been recognized as the key to improved, on-time and on-budget delivery of software and systems projects. This book provides practical teaching for graduate and professional systems and software engineers. It uses extensive case studies and exercises to help students grasp concepts and techniques. With a focus on software-intensive systems, this text provides a probing and comprehensive review of recent developments in intelligent systems, soft computing techniques, and their diverse applications in manufacturing. The second edition contains 100% revised content and approximately 30% new material

  10. Biochemical process of ureolysis-based microbial CaCO3 precipitation and its application in self-healing concrete.

    Science.gov (United States)

    Xu, Jing; Wang, Xianzhi; Wang, Binbin

    2018-04-01

    Urea hydrolysis has already been considered as the most effective pathway for microbially induced CaCO 3 precipitation (MICP). The present work first studied the combination of several key factors including initial pH, temperature, and dosage of urea, which contribute to the biochemical process of MICP. Under an amiable condition of pH and temperature, the dosage of urea has a significant impact on the rate of urea degradation and CaCO 3 precipitation. A bacteria-based self-healing system was developed by loading healing agents on ceramsite carriers. The self-healing efficiency was evaluated by visual inspection on crack closure, compressive strength regain, and capillary water absorption. A preferable healing effectiveness was obtained when the bacteria and organic nutrients were co-immobilized in carriers. Image analysis showed that cracks up to 273 μm could be healed with a crack closure ratio of 86% in 28 days. The compressive strength regain increased 24% and the water absorption coefficient decreased 27% compared to the reference. The findings indicated a promising application of ureolysis-based MICP in restoring the mechanical properties and enhancing the durability of concrete.

  11. Self-healing phenomena on corroding steel in simulated pore water and mortar, substantiated via cyclic voltammetry and surface analysis

    Energy Technology Data Exchange (ETDEWEB)

    Koleva, D. A.; Breugel, K. van [Delft University of Technology, The Netherlands Faculty of CiTG, Department Materials and Environment, Delf (Netherlands); Hu, J. [School of Materials Science and Engineering, South China University of Technology, Guangzhou (China); Kolev, H. [Bulgarian Academy of Sciences, Institute of Catalysis, Sofia (Bulgaria)

    2013-07-01

    The application of polymeric nano-particles was investigated as an approach to control corrosion and/or self-heal corrosion damage on steel in simulated alkaline medium and reinforced mortar. The “self-healing agent”, present in the closed inner volume of PEO-b-PS vesicles was Ca-based and chosen as such due to the natural predominance of Ca in the investigated system. The vesicles’ concentration was 0.0024 wt.% in the model medium and 0.025 wt.% per cement weight for the case of mortar. Therefore, a “self-repair” or “self-healing” of the steel product layer solely due to the Ca- component is not realistic in view of these minimal concentrations. The most plausible mechanism is the nature of incorporation of the Ca-containing vesicles in the product layer, enhanced chloride binding effects and adsorption on active sites on the steel surface. A more uniform and stable surface layer, initial pitting formation and propagation, but consecutive “healing”, are evidenced by surface analysis and electrochemical response i.e. largely reduced anodic and corrosion currents and no further pit propagation are observed when Ca-containing vesicles are present in the model medium. Corrosion products-free steel/cement paste interface is relevant for the reinforced mortar, containing Ca-rich vesicles in contrast to vesicles-free and empty vesicles-containing matrix. Key words: corrosion; concrete; polymeric nano-particles; CVA; SEM; XRD; XPS.

  12. PENGARUH EFEKTIVITAS TERAPI SELF HEALING MENGGUNAKAN ENERGI REIKI TERHADAP KECEMASAN MENGHADAPI UJIAN SKRIPSI

    Directory of Open Access Journals (Sweden)

    Budiman Bahrien

    2017-06-01

    Full Text Available The educational process can become a source of stressor and anxiety, especially in the final stage of a college education (thesis exam for students. 5 of 15 College student Health Sciences Muhammadiyah Palembang experienced acute anxiety. In addition, 19 of the 67 students in STIKes Muhammadiyah who undergo remedial thesis examination have other physical complaints. Self healing using reiki energy can be utilized to reduce the anxiety state. This study investigates the effect of self healing reiki energy on anxiety. A quasi experimental design was used with the sample of forty respondents (20=intervention, 20=control group. One Way Anova was used to test the hypothesis. The results showed that there was a significant difference of the mean score of anxiety between the intervention and the control group during the post-test. Thus, treatment of self healing with Reiki energy is quite effective in reducing anxiety levels.

  13. Thermally induced self-healing epoxy/glass laminates with porous layers containing crystallized healing agent

    Directory of Open Access Journals (Sweden)

    T. Szmechtyk

    2018-07-01

    Full Text Available Porous glass fiber and paper layers were tested for application in thermally induced self healing epoxy laminates as healing porous layers. Both types of layers were impregnated using high purity bisphenol A diglycidyl ether (BADGE epoxy with ability to crystallize during storage under 25 °C. Absorption capacity of porous layers was evaluated. Differential scanning calorimetry was used to investigate BADGE healing agent recrystallization process. Healing porous glass layers (HPGL were selected for further tests. Liquid chromatography and Fourier transform infrared (FT IR spectroscopy provided information about average molecular mass of embedded healing agent and functional groups in HPGL layers. Self-healing efficiency of three different laminates with HPGL layers was calculated based on the results of three-point bending test and Charpy impact test. Also, flexural properties and impact strength of laminates were evaluated. The obtained results confirm competitive self healing ability of composites with HPGL.

  14. Self-healing of cracks in Ag joining layer for die-attachment in power devices

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chuantong, E-mail: chenchuantong@sanken.osaka-u.ac.jp; Nagao, Shijo; Suganuma, Katsuaki; Jiu, Jinting; Zhang, Hao; Sugahara, Tohru [Institute of Scientific and Industrial Research, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047 (Japan); Iwashige, Tomohito; Sugiura, Kazuhiko; Tsuruta, Kazuhiro [Research Division 3, Denso Corporation, Komenoki-cho, Minamiyama 500-1, Nissin, Aichi 470-0111 (Japan)

    2016-08-29

    Sintered silver (Ag) joining has attracted significant interest in power devices modules for its ability to form stable joints with a porous interconnection layer. A function for the self-healing of cracks in sintered porous Ag interlayers at high temperatures is discovered and reported here. A crack which was prepared on a Ag joining layer was closed after heating at 200 °C in air. The tensile strength of pre-cracked Ag joining layer specimens recovers to the value of non-cracked specimens after heating treatment. Transmission electron microscopy (TEM) was used to probe the self-healing mechanism. TEM images and electron diffraction patterns show that a large quantity of Ag nanoparticles formed at the gap with the size less than 10 nm, which bridges the crack in the self-healing process. This discovery provides additional motivation for the application of Ag as an interconnection material for power devices at high temperature.

  15. Biomimetics in materials science self-healing, self-lubricating, and self-cleaning materials

    CERN Document Server

    Nosonovsky, Michael

    2012-01-01

    Biomimetics in Materials Science provides a comprehensive theoretical and practical review of biomimetic materials with self-healing, self-lubricating and self-cleaning properties. These three topics are closely related and constitute rapidly developing areas of study. The field of self-healing materials requires a new conceptual understanding of this biomimetic technology, which is in contrast to traditional  engineering processes such as wear and fatigue.  Biomimetics in Materials Science is the first monograph to be devoted to these materials. A new theoretical framework for these processes is presented based on the concept of multi-scale structure of entropy and non-equilibrium thermodynamics, together with a detailed review of the available technology. The latter includes experimental, modeling, and simulation results obtained on self-healing/lubricating/cleaning materials since their emergence in the past decade. Describes smart, biomimetic materials in the context of nanotechnology, biotechnology, an...

  16. Facile preparation of self-healing superhydrophobic CeO2 surface by electrochemical processes

    Science.gov (United States)

    Nakayama, Katsutoshi; Hiraga, Takuya; Zhu, Chunyu; Tsuji, Etsushi; Aoki, Yoshitaka; Habazaki, Hiroki

    2017-11-01

    Herein we report simple electrochemical processes to fabricate a self-healing superhydrophobic CeO2 coating on Type 304 stainless steel. The CeO2 surface anodically deposited on flat stainless steel surface is hydrophilic, although high temperature-sintered and sputter-deposited CeO2 surface was reported to be hydrophobic. The anodically deposited hydrophilic CeO2 surface is transformed to hydrophobic during air exposure. Specific accumulation of contaminant hydrocarbon on the CeO2 surface is responsible for the transformation to hydrophobic state. The deposition of CeO2 on hierarchically rough stainless steel surface produces superhydrophobic CeO2 surface, which also shows self-healing ability; the surface changes to superhydrophilic after oxygen plasma treatment but superhydrophobic state is recovered repeatedly by air exposure. This work provides a facile method for preparing a self-healing superhydrophobic surface using practical electrochemical processes.

  17. Development of a fatigue analysis software system

    International Nuclear Information System (INIS)

    Choi, B. I.; Lee, H. J.; Han, S. W.; Kim, J. Y.; Hwang, K. H.; Kang, J. Y.

    2001-01-01

    A general purpose fatigue analysis software to predict fatigue lives of mechanical components and structures was developed. This software has some characteristic features including functions of searching weak regions on the free surface in order to reduce computing time significantly, a database of fatigue properties for various materials, and an expert system which can assist any users to get more proper results. This software can be used in the environment consists of commercial finite element packages. Using the software developed fatigue analyses for a SAE keyhole specimen and an automobile knuckle were carried out. It was observed that the results were agree well with those from commercial packages

  18. Software quality assurance: in large scale and complex software-intensive systems

    NARCIS (Netherlands)

    Mistrik, I.; Soley, R.; Ali, N.; Grundy, J.; Tekinerdogan, B.

    2015-01-01

    Software Quality Assurance in Large Scale and Complex Software-intensive Systems presents novel and high-quality research related approaches that relate the quality of software architecture to system requirements, system architecture and enterprise-architecture, or software testing. Modern software

  19. Trend Monitoring System (TMS) graphics software

    Science.gov (United States)

    Brown, J. S.

    1979-01-01

    A prototype bus communications systems, which is being used to support the Trend Monitoring System (TMS) and to evaluate the bus concept is considered. A set of FORTRAN-callable graphics subroutines for the host MODCOMP comuter, and an approach to splitting graphics work between the host and the system's intelligent graphics terminals are described. The graphics software in the MODCOMP and the operating software package written for the graphics terminals are included.

  20. Ensuring system security through formal software evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Howell, J A; Fuyat, C [Los Alamos National Lab., NM (United States); Elvy, M [Marble Associates, Boston, MA (United States)

    1992-01-01

    With the increasing use of computer systems and networks to process safeguards information in nuclear facilities, the issue of system and data integrity is receiving worldwide attention. Among the many considerations are validation that the software performs as intended and that the information is adequately protected. Such validations are often requested of the Safeguards Systems Group of the Los Alamos National Laboratory. This paper describes our methodology for performing these software evaluations.

  1. Self-healing effect of the protective inhibitor-containing coatings on Mg alloys

    Science.gov (United States)

    Gnedenkov, A. S.; Sinebryukhov, S. L.; Mashtalyar, D. V.; Gnedenkov, S. V.

    2017-09-01

    The method of self-healing coating formation on the surface of magnesium alloys on the base of plasma electrolytic oxidation (PEO) with subsequent impregnation of the obtained layer with inhibitor has been suggested. The protective and electrochemical properties of such coatings have been described. Localised Scanning Electrochemical Methods were used for determining the kinetics and mechanism of the self-healing process. The treatment with the solution containing inhibitor enables us to increase the protective properties of the PEO-coating in 30 times in the corrosion-active environment.

  2. Multiple self-healing squamous epithelioma er en arvelig tilstand med selvhelende hudkræft

    DEFF Research Database (Denmark)

    Broesby-Olsen, Sigurd; Frandsen, Stine Krog; Thomassen, Mads

    2012-01-01

    Multiple self-healing squamous epithelioma - Ferguson-Smith disease (MSSE) is an autosomal dominant inherited disease with multiple, recurrent, histologically malignant tumours that undergo spontaneous regression. The gene for MSSE has recently been identified as the transforming growth factor-be......-beta receptor 1 (TGFBR1). Although rare, MSSE constitutes an important model of tumour-biology research. The discovery of the genetic background for MSSE paves the way for further elucidating the mechanisms involved in this peculiar self-healing cancer syndrome....

  3. Software design for resilient computer systems

    CERN Document Server

    Schagaev, Igor

    2016-01-01

    This book addresses the question of how system software should be designed to account for faults, and which fault tolerance features it should provide for highest reliability. The authors first show how the system software interacts with the hardware to tolerate faults. They analyze and further develop the theory of fault tolerance to understand the different ways to increase the reliability of a system, with special attention on the role of system software in this process. They further develop the general algorithm of fault tolerance (GAFT) with its three main processes: hardware checking, preparation for recovery, and the recovery procedure. For each of the three processes, they analyze the requirements and properties theoretically and give possible implementation scenarios and system software support required. Based on the theoretical results, the authors derive an Oberon-based programming language with direct support of the three processes of GAFT. In the last part of this book, they introduce a simulator...

  4. Coordination Approaches for Complex Software Systems

    NARCIS (Netherlands)

    Bosse, T.; Hoogendoorn, M.; Treur, J.

    2006-01-01

    This document presents the results of a collaboration between the Vrije Universiteit Amsterdam, Department of Artificial Intelligence and Force Vision to investigate coordination approaches for complex software systems. The project was funded by Force Vision.

  5. Architecting Fault-Tolerant Software Systems

    NARCIS (Netherlands)

    Sözer, Hasan

    2009-01-01

    The increasing size and complexity of software systems makes it hard to prevent or remove all possible faults. Faults that remain in the system can eventually lead to a system failure. Fault tolerance techniques are introduced for enabling systems to recover and continue operation when they are

  6. Monitoring the restoration of interfacial contact for self healing thermal interface materials for LED and microelectronic applications

    NARCIS (Netherlands)

    Lafont, U.L.; Van Zeijl, H.W.; Van der Zwaag, S.

    2013-01-01

    While conventional self healing materials focus on the restoration of mechanical properties, newer generations of self healing materials focus on the restoration of other functional (i.e. non-mechanical) properties. Thermal conductivity is an example of an important functional property of a Thermal

  7. Advanced Languages for Systems Software

    Science.gov (United States)

    1994-01-01

    in performance. Specific examples of well-structured systems include the microkernel architecture of the Mach 3.0 operating system and the modular... microkernels as a first step towards building a completely modular operating system from a set of composable services. However, just as the idea of a...microprotocol in the x-kernel is a design principle, rather than a formally realized construct, the modularity of microkernels is largely a matter of

  8. Adaptive intrusion data system (AIDS) software routines

    International Nuclear Information System (INIS)

    Corlis, N.E.

    1980-07-01

    An Adaptive Intrusion Data System (AIDS) was developed to collect information from intrusion alarm sensors as part of an evaluation system to improve sensor performance. AIDS is a unique digital data-compression, storage, and formatting system; it also incorporates a capability for video selection and recording for assessment of the sensors monitored by the system. The system is software reprogrammable to numerous configurations that may be used for the collection of environmental, bilevel, analog, and video data. This report describes the software routines that control the different AIDS data-collection modes, the diagnostic programs to test the operating hardware, and the data format. Sample data printouts are also included

  9. Self-healing polyurethane/attapulgite nanocomposites based on disulfide bonds and shape memory effect

    International Nuclear Information System (INIS)

    Xu, Yurun; Chen, Dajun

    2017-01-01

    Nanocomposites with remarkable enhanced mechanical properties have attracted great research efforts recently. In this work, a series of self-healing polyurethane/attapulgite nanocomposites were prepared by solution blending. Introducing self-healing ability and attapulgite (AT) reinforcement simultaneously led to prolonged material lifetime and enhanced mechanical properties. Scanning electron microscope (SEM) observation indicated that AT could achieve a uniform dispersion in polyurethane matrix when AT content was relatively low. The influences on mechanical properties were evaluated by tensile test. Results showed that incorporating an appropriate content of AT would lead to an enhanced tensile properties. The interactions between AT and polyurethane matrix were studied by effective cross-linking density calculation and Fourier transform infrared (FTIR) analysis. Results indicated that rich hydrogen bonds were formed between AT and polyurethane matrix. Displacement data was utilized to evaluate the influence on shape memory effect. With the incorporation of AT, deformation of the sample under external force was restrained. Meanwhile, closure of the scratches still can be accomplished during healing process. Results of healing test suggested that incorporating 1% of AT would also promote self-healing property. - Highlights: • Composites with both self-healing and enhanced mechanical property are prepared. • Healing mechanism relies on disulfide exchange reaction and shape memory effect. • Mechanical enhancement is caused by rich hydrogen bonds introduced by attapulgite.

  10. A critical appraisal of the potential of self healing polymeric coatings

    NARCIS (Netherlands)

    García, S.J.; Fischer, H.R.; Zwaag, S. van der

    2011-01-01

    Several approaches and concepts to self healing materials have appeared in the literature over the last years, all presenting advantages and disadvantages, but definitely showing the great potential of this new class of materials to increase the lifetime of structures and to decrease maintenance

  11. Micromechanical properties of a new polymeric microcapsule for self-healing cementitious materials

    NARCIS (Netherlands)

    Lv, Leyang; Schlangen, H.E.J.G.; Yang, Z.; Xing, Feng

    2016-01-01

    Self-healing cementitious materials containing a microencapsulated healing agent are appealing due to their great application potential in improving the serviceability and durability of concrete structures. In this study, poly(phenol-formaldehyde) (PF) microcapsules that aim to provide a

  12. Micromechanical Properties of a New Polymeric Microcapsule for Self-Healing Cementitious Materials

    Directory of Open Access Journals (Sweden)

    Leyang Lv

    2016-12-01

    Full Text Available Self-healing cementitious materials containing a microencapsulated healing agent are appealing due to their great application potential in improving the serviceability and durability of concrete structures. In this study, poly(phenol–formaldehyde (PF microcapsules that aim to provide a self-healing function for cementitious materials were prepared by an in situ polymerization reaction. Size gradation of the synthesized microcapsules was achieved through a series of sieving processes. The shell thickness and the diameter of single microcapsules was accurately measured under environmental scanning electron microscopy (ESEM. The relationship between the physical properties of the synthesized microcapsules and their micromechanical properties were investigated using nanoindentation. The results of the mechanical tests show that, with the increase of the mean size of microcapsules and the decrease of shell thickness, the mechanical force required to trigger the self-healing function of microcapsules increased correspondingly from 68.5 ± 41.6 mN to 198.5 ± 31.6 mN, featuring a multi-sensitive trigger function. Finally, the rupture behavior and crack surface of cement paste with embedded microcapsules were observed and analyzed using X-ray computed tomography (XCT. The synthesized PF microcapsules may find potential application in self-healing cementitious materials.

  13. High-Temperature Self-Healing and Re-Adhering Geothermal Well Cement Composites

    Science.gov (United States)

    Pyatina, T.; Sugama, T.; Boodhan, Y.; Nazarov, L.

    2017-12-01

    Self-healing cementitious materials are particularly attractive for the cases where damaged areas are difficult to locate and reach. High-temperature geothermal wells with aggressive environments impose most difficult conditions on cements that must ensure durable zonal isolation under repeated thermal, chemical and mechanical stresses. The present work evaluates matrix and carbon steel (CS) - cement interface self-healing and re-adhering properties of various inorganic cementitious composites under steam, alkali carbonate or brine environments at 270-300oC applicable to geothermal wells. The composite materials included blends based on Ordinary Portland Cement (OPC) and natural zeolites and alkali or phosphate activated composites of Calcium Aluminate Cement (CAC) with fly ash, class F. Class G cement blend with crystalline silica was used as a baseline. Compressive-strength and bond-strength recoveries were examined to evaluate self-healing and re-adhering properties of the composites after repeated crush tests followed by 5-day healing periods in these environments. The optical and scanning electron microscopes, X-ray diffraction, Fourier Transform infrared, Raman spectroscopy and EDX measurements were used to identify phases participating in the strengths recoveries and cracks filling processes. Amorphous silica-rich- and small-size crystalline phases played an important role in the healing of the tested composites in all environments. Possible ways to enhance self-healing properties of cementitious composites under conditions of geothermal wells were identified.

  14. Thermally Self-Healing Polymeric Materials : The Next Step to Recycling Thermoset Polymers?

    NARCIS (Netherlands)

    Zhang, Youchun; Broekhuis, Antonius A.; Picchioni, Francesco

    2009-01-01

    We developed thermally self-healing polymeric materials on the basis of furan-functionalized, alternating thermosetting polyketones (PK-furan) and bis-maleimide by using the Diels-Alder (DA) and Retro-Diels-Alder (RDA) reaction sequence. PK-furan can be easily obtained under mild conditions by the

  15. Understanding the molecular mechanisms involved in the interfacial self-healing of supramolecular rubbers

    NARCIS (Netherlands)

    Bose, R.K.; Garcia Espallargas, S.J.; Van der Zwaag, S.

    2013-01-01

    Supramolecular rubbers based on 2-aminoethylimidazolidone and fatty acids with epoxy crosslinks have been shown to self-heal via multiple hydrogen bonding sites. In this work, several tools are used to investigate the molecular mechanisms taking place at the interface to understand cohesive healing

  16. Light triggered interfacial damage self-healing of poly(p-phenylene benzobisoxazole) fiber composites

    Science.gov (United States)

    Hu, Zhen; Shao, Qing; Huang, Yudong; Yu, Long; Zhang, Dayu; Xu, Xirong; Lin, Jing; Liu, Hu; Guo, Zhanhu

    2018-05-01

    The interfacial microcracks in the resin matrix composites are difficult to be detected and repaired. However, the self-healing concept provides opportunities to fabricate composites with unusual properties. In the present study, photothermal conversion Ag-Cu2S nanoparticles were immobilized onto poly(p-phenylene benzobisoxazole) (PBO) fibers via a polydopamine chemistry. Benefitting from the photothermal effects of Ag-Cu2S, the obtained PBO fibers (Ag-Cu2S-PBO) efficiently converted the light energy into heat under Xenon lamp irradiation. Then, single PBO fiber composites were prepared using thermoplastic polyurethane as the matrix. It was found that the interfacial damage caused by single fiber pull-out was simply self-healed by Xe light irradiation. This wonderful interfacial damage self-healing property was mainly attributed to the in situ heating generation via photothermal effects of Ag-Cu2S in the composite interface. This paper reports a novel strategy to construct advanced composites with light-triggered self-healing properties, which will provide inspiration for preparing high performance composite materials.

  17. Self-healing polyurethane/attapulgite nanocomposites based on disulfide bonds and shape memory effect

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yurun; Chen, Dajun, E-mail: cdj@dhu.edu.cn

    2017-07-01

    Nanocomposites with remarkable enhanced mechanical properties have attracted great research efforts recently. In this work, a series of self-healing polyurethane/attapulgite nanocomposites were prepared by solution blending. Introducing self-healing ability and attapulgite (AT) reinforcement simultaneously led to prolonged material lifetime and enhanced mechanical properties. Scanning electron microscope (SEM) observation indicated that AT could achieve a uniform dispersion in polyurethane matrix when AT content was relatively low. The influences on mechanical properties were evaluated by tensile test. Results showed that incorporating an appropriate content of AT would lead to an enhanced tensile properties. The interactions between AT and polyurethane matrix were studied by effective cross-linking density calculation and Fourier transform infrared (FTIR) analysis. Results indicated that rich hydrogen bonds were formed between AT and polyurethane matrix. Displacement data was utilized to evaluate the influence on shape memory effect. With the incorporation of AT, deformation of the sample under external force was restrained. Meanwhile, closure of the scratches still can be accomplished during healing process. Results of healing test suggested that incorporating 1% of AT would also promote self-healing property. - Highlights: • Composites with both self-healing and enhanced mechanical property are prepared. • Healing mechanism relies on disulfide exchange reaction and shape memory effect. • Mechanical enhancement is caused by rich hydrogen bonds introduced by attapulgite.

  18. Epithelial self-healing is recapitulated by a 3D biomimetic E-cadherin junction

    NARCIS (Netherlands)

    Cohen, Daniel J.; Gloerich, Martijn; Nelson, W. James

    2016-01-01

    Epithelial monolayers undergo self-healing when wounded. During healing, cells collectively migrate into the wound site, and the converging tissue fronts collide and form a stable interface. To heal, migrating tissues must form cell-cell adhesions and reorganize from the front-rear polarity

  19. Tough Self-Healing Elastomers by Molecular Enforced Integration of Covalent and Reversible Networks.

    Science.gov (United States)

    Wu, Jinrong; Cai, Li-Heng; Weitz, David A

    2017-10-01

    Self-healing polymers crosslinked by solely reversible bonds are intrinsically weaker than common covalently crosslinked networks. Introducing covalent crosslinks into a reversible network would improve mechanical strength. It is challenging, however, to apply this concept to "dry" elastomers, largely because reversible crosslinks such as hydrogen bonds are often polar motifs, whereas covalent crosslinks are nonpolar motifs. These two types of bonds are intrinsically immiscible without cosolvents. Here, we design and fabricate a hybrid polymer network by crosslinking randomly branched polymers carrying motifs that can form both reversible hydrogen bonds and permanent covalent crosslinks. The randomly branched polymer links such two types of bonds and forces them to mix on the molecular level without cosolvents. This enables a hybrid "dry" elastomer that is very tough with fracture energy 13500 Jm -2 comparable to that of natural rubber. Moreover, the elastomer can self-heal at room temperature with a recovered tensile strength 4 MPa, which is 30% of its original value, yet comparable to the pristine strength of existing self-healing polymers. The concept of forcing covalent and reversible bonds to mix at molecular scale to create a homogenous network is quite general and should enable development of tough, self-healing polymers of practical usage. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Modeling Self-Healing of Concrete Using Hybrid Genetic Algorithm-Artificial Neural Network.

    Science.gov (United States)

    Ramadan Suleiman, Ahmed; Nehdi, Moncef L

    2017-02-07

    This paper presents an approach to predicting the intrinsic self-healing in concrete using a hybrid genetic algorithm-artificial neural network (GA-ANN). A genetic algorithm was implemented in the network as a stochastic optimizing tool for the initial optimal weights and biases. This approach can assist the network in achieving a global optimum and avoid the possibility of the network getting trapped at local optima. The proposed model was trained and validated using an especially built database using various experimental studies retrieved from the open literature. The model inputs include the cement content, water-to-cement ratio (w/c), type and dosage of supplementary cementitious materials, bio-healing materials, and both expansive and crystalline additives. Self-healing indicated by means of crack width is the model output. The results showed that the proposed GA-ANN model is capable of capturing the complex effects of various self-healing agents (e.g., biochemical material, silica-based additive, expansive and crystalline components) on the self-healing performance in cement-based materials.

  1. Chloride transport under compressive load in bacteria-based self-healing concrete

    NARCIS (Netherlands)

    Binti Md Yunus, B.; Schlangen, E.; Jonkers, H.M.

    2015-01-01

    An experiment was carried out in this study to investigate the effect of compressive load on chloride penetration in self-healing concrete containing bacterial-based healing agent. Bacteria-based healing agent with the fraction of 2 mm – 4 mm of particles sizes were used in this contribution. ESEM

  2. Intrinsic self-healing thermoset through covalent and hydrogen bonding interactions

    NARCIS (Netherlands)

    Araya-Hermosilla, R.; Lima, G. M. R.; Raffa, P.; Fortunato, G.; Pucci, A.; Flores, Mario E.; Moreno-Villoslada, I.; Broekhuis, A. A.; Picchioni, F.

    The intrinsic self-healing ability of polyketone (PK) chemically modified into furan and/or OH groups containing derivatives is presented. Polymers bearing different ratios of both functional groups were cross-linked via furan/bis-maleimide (Diels-Alder adducts) and hydrogen bonding interactions

  3. Microcapsule-Type Self-Healing Protective Coating for Cementitious Composites with Secondary Crack Preventing Ability.

    Science.gov (United States)

    Kim, Dong-Min; Yu, Hwan-Chul; Yang, Hye-In; Cho, Yu-Jin; Lee, Kwang-Myong; Chung, Chan-Moon

    2017-01-26

    A microcapsule-type self-healing protective coating with secondary crack preventing capability has been developed using a silanol-terminated polydimethylsiloxane (STP)/dibutyltin dilaurate (DD) healing agent. STP undergoes condensation reaction in the presence of DD to give a viscoelastic substance. STP- and DD-containing microcapsules were prepared by in-situ polymerization and interfacial polymerization methods, respectively. The microcapsules were characterized by Fourier-transform infrared (FT-IR) spectroscopy, optical microscopy, and scanning electron microscopy (SEM). The microcapsules were integrated into commercial enamel paint or epoxy coating formulations, which were applied on silicon wafers, steel panels, and mortar specimens to make dual-capsule self-healing protective coatings. When the STP/DD-based coating was scratched, self-healing of the damaged region occurred, which was demonstrated by SEM, electrochemical test, and water permeability test. It was also confirmed that secondary crack did not occur in the healed region upon application of vigorous vibration to the self-healing coating.

  4. Microcapsule-Type Self-Healing Protective Coating for Cementitious Composites with Secondary Crack Preventing Ability

    Directory of Open Access Journals (Sweden)

    Dong-Min Kim

    2017-01-01

    Full Text Available A microcapsule-type self-healing protective coating with secondary crack preventing capability has been developed using a silanol-terminated polydimethylsiloxane (STP/dibutyltin dilaurate (DD healing agent. STP undergoes condensation reaction in the presence of DD to give a viscoelastic substance. STP- and DD-containing microcapsules were prepared by in-situ polymerization and interfacial polymerization methods, respectively. The microcapsules were characterized by Fourier-transform infrared (FT-IR spectroscopy, optical microscopy, and scanning electron microscopy (SEM. The microcapsules were integrated into commercial enamel paint or epoxy coating formulations, which were applied on silicon wafers, steel panels, and mortar specimens to make dual-capsule self-healing protective coatings. When the STP/DD-based coating was scratched, self-healing of the damaged region occurred, which was demonstrated by SEM, electrochemical test, and water permeability test. It was also confirmed that secondary crack did not occur in the healed region upon application of vigorous vibration to the self-healing coating.

  5. Design and testing of tubular polymeric capsules for self-healing of concrete

    Science.gov (United States)

    Araújo, M.; Van Tittelboom, K.; Feiteira, J.; Gruyaert, E.; Chatrabhuti, S.; Raquez, J.-M.; Šavija, B.; Alderete, N.; Schlangen, E.; De Belie, N.

    2017-10-01

    Polymeric healing agents have proven their efficiency to heal cracks in concrete in an autonomous way. However, the bottleneck for valorisation of self-healing concrete with polymeric healing agents is their encapsulation. In the present work, the suitability of polymeric materials such as poly(methyl methacrylate) (PMMA), polystyrene (PS) and poly(lactic acid) (PLA) as carriers for healing agents in self-healing concrete has been evaluated. The durability of the polymeric capsules in different environments (demineralized water, salt water and simulated concrete pore solution) and their compatibility with various healing agents have been assessed. Next, a numerical model was used to simulate capsule rupture when intersected by a crack in concrete and validated experimentally. Finally, two real-scale self-healing concrete beams were made, containing the selected polymeric capsules (with the best properties regarding resistance to concrete mixing and breakage upon crack formation) or glass capsules and a reference beam without capsules. The self-healing efficiency was determined after crack creation by 3-point-bending tests.

  6. A novel methodology for self-healing at the nanoscale in CNT/epoxy composites

    Science.gov (United States)

    Quigley, E.; Datta, S.; Chattopadhyay, A.

    2016-04-01

    Self-healing materials have the potential to repair induced damage and extend the service life of aerospace or civil components as well as prevent catastrophic failure. A novel technique to provide self-healing capabilities at the nanoscale in carbon nanotube/epoxy nanocomposites is presented in this paper. Carbon nanotubes (CNTs) functionalized with the healing agent (dicyclopentadiene) were used to fabricate self-healing CNT/epoxy nanocomposite films. The structure of CNTs was considered suitable for this application since they are nanosized, hollow, and provide a more consistent size distribution than polymeric nanocapsules. Specimens with different weight fractions of the functionalized CNTs were fabricated to explore the effect of weight fraction of functionalized CNTs on the extent of healing. Optical micrographs with different fluorescent filters showed partial or complete healing of damage approximately two to three weeks after damage was induced. Results indicate that by using CNTs to encapsulate a healing agent, crack growth in self-healing CNT/epoxy nanocomposites can be retarded, leading to safer materials that can autonomously repair itself.

  7. Influence of the Microwave Heating Time on the Self-Healing Properties of Asphalt Mixtures

    Directory of Open Access Journals (Sweden)

    Jose Norambuena-Contreras

    2017-10-01

    Full Text Available This paper aims to evaluate the influence of the microwave heating time on the self-healing properties of fibre-reinforced asphalt mixtures. To this purpose, self-healing properties of dense asphalt mixtures with four different percentages of steel wool fibres were evaluated as the three-point bending strength before and after healing via microwave heating at four different heating times. Furthermore, the thermal behaviour of asphalt mixtures during microwave heating was also evaluated. With the aim of quantifying the efficiency of the repair process, ten damage-healing cycles were done in the test samples. In addition, self-healing results were compared with the fibre spatial distribution inside asphalt samples evaluated by CT-scans. Crack-size change on asphalt samples during healing cycles was also evaluated through optical microscopy. It was found that the heating time is the most influential variable on the healing level reached by the asphalt mixtures tested by microwave radiation. CT-Scans results proved that fibre spatial distribution into the asphalt mixtures play an important role in the asphalt healing level. Finally, it was concluded that 40 s was the optimum heating time to reach the highest healing levels with the lowest damage on the asphalt samples, and that heating times over 30 s can seal the cracks, thus achieving the self-healing of asphalt mixtures via microwave heating.

  8. Clinical software for MR imaging system, 4

    International Nuclear Information System (INIS)

    Shimizu, Koji; Kasai, Akira; Okamura, Shoichi

    1992-01-01

    Magnetic resonance imaging continues to elicit new application software through the recent technological advances of MR equipment. This paper describes several applications of our newly developed clinical software. The fast SE sequence (RISE) has proved to reduce routine examination time and to improve image quality, and ultra-fast FE sequence (SMASH) was found to extend the diagnostic capabilities in the field of cardiac study. Diffusion/perfusion imaging achieved in our MR system showed significant promise for providing novel information regarding tissue characterization. Furthermore, Image quality and practicalities of MR angiography have been improved by advanced imaging sequences and sophisticated post-processing software. (author)

  9. X-ray computed microtomography of three-dimensional microcracks and self-healing in engineered cementitious composites

    International Nuclear Information System (INIS)

    Fan, Shuai; Li, Mo

    2015-01-01

    Concrete cracking and deterioration can potentially be addressed by innovative self-healing cementitious materials, which can autogenously regain transport properties and mechanical characteristics after the damage self-healing process. For the development of such materials, it is crucial, but challenging, to precisely characterize the extent and quality of self-healing due to a variety of factors. This study adopted x-ray computed microtomography (μCT) to derive three-dimensional morphological data on microcracks before and after healing in engineered cementitious composite (ECC). Scanning electron microscope and energy dispersive x-ray spectroscopy were also used to morphologically and chemically analyze the healing products. This work showed that the evolution of the microcrack 3D structure due to self-healing in cementitious materials can be directly and quantitatively characterized by μCT. A detailed description of the μCT image analysis method applied to ECC self-healing was presented. The results revealed that the self-healing extent and rate strongly depended on initial surface crack width, with smaller crack width favoring fast and robust self-healing. We also found that the self-healing mechanism in cementitious materials is dependent on crack depth. The region of a crack close to the surface (from 0 to around 50–150 μm below the surface) can be sealed quickly with crystalline precipitates. However, at greater depths the healing process inside the crack takes a significantly longer time to occur, with healing products more likely resulting from continued hydration and pozzolanic reactions. Finally, the μCT method was compared with other self-healing characterization methods, with discussions on its importance in generating new scientific knowledge for the development of robust self-healing cementitious materials. (paper)

  10. MPS [Multiparticle Spectrometer] data acquisition software system

    International Nuclear Information System (INIS)

    Saulys, A.C.; Etkin, A.; Foley, K.J.

    1989-01-01

    A description of the software for a FASTBUS based data acquisition system in use at the Brookhaven National Laboratory Multiparticle Spectrometer is presented. Data reading and formatting is done by the SLAC Scanner Processors (SSP's) resident in the FASTBUS system. A multiprocess software system on VAX computers is used to communicate with the SSP's, record the data, and monitor on-line the progress of high energy and heavy ion experiments. The structure and the performance of this system are discussed. 4 refs., 1 fig

  11. Automated software configuration in the MONSOON system

    Science.gov (United States)

    Daly, Philip N.; Buchholz, Nick C.; Moore, Peter C.

    2004-09-01

    MONSOON is the next generation OUV-IR controller project being developed at NOAO. The design is flexible, emphasizing code re-use, maintainability and scalability as key factors. The software needs to support widely divergent detector systems ranging from multi-chip mosaics (for LSST, QUOTA, ODI and NEWFIRM) down to large single or multi-detector laboratory development systems. In order for this flexibility to be effective and safe, the software must be able to configure itself to the requirements of the attached detector system at startup. The basic building block of all MONSOON systems is the PAN-DHE pair which make up a single data acquisition node. In this paper we discuss the software solutions used in the automatic PAN configuration system.

  12. Automated Cryocooler Monitor and Control System Software

    Science.gov (United States)

    Britchcliffe, Michael J.; Conroy, Bruce L.; Anderson, Paul E.; Wilson, Ahmad

    2011-01-01

    This software is used in an automated cryogenic control system developed to monitor and control the operation of small-scale cryocoolers. The system was designed to automate the cryogenically cooled low-noise amplifier system described in "Automated Cryocooler Monitor and Control System" (NPO-47246), NASA Tech Briefs, Vol. 35, No. 5 (May 2011), page 7a. The software contains algorithms necessary to convert non-linear output voltages from the cryogenic diode-type thermometers and vacuum pressure and helium pressure sensors, to temperature and pressure units. The control function algorithms use the monitor data to control the cooler power, vacuum solenoid, vacuum pump, and electrical warm-up heaters. The control algorithms are based on a rule-based system that activates the required device based on the operating mode. The external interface is Web-based. It acts as a Web server, providing pages for monitor, control, and configuration. No client software from the external user is required.

  13. Initial Self-Healing Temperatures of Asphalt Mastics Based on Flow Behavior Index

    Directory of Open Access Journals (Sweden)

    Chao Li

    2018-05-01

    Full Text Available Increasing temperature is a simple and convenient method to accelerate the self-healing process of bitumen. However, bitumen may not achieve the healing capability at lower temperature, and may be aged if temperature is too high. In addition, the bitumen is mixed with mineral filler and formed as asphalt mastic in asphalt concrete, so it is more accurate to study the initial self-healing from the perspective of asphalt mastic. The primary purpose of this research was to examine the initial self-healing temperature of asphalt mastic, which was determined by the flow behavior index obtained from the flow characteristics. Firstly, the texture and geometry characteristics of two fillers were analyzed, and then the initial self-healing temperature of nine types of asphalt mastic, pure bitumen (PB and styrene-butadiene-styrene (SBS modified bitumen were determined by the flow behavior index. Results demonstrate that the average standard deviation of gray-scale texture value of limestone filler (LF is 21.24% lower than that of steel slag filler (SSF, showing that the steel slag filler has a better particle distribution and geometry characteristics. Also the initial self-healing temperatures of asphalt mastics with 0.2, 0.4 and 0.6 LF-PB volume ratio are 46.5 °C, 47.2 °C and 49.4 °C, which are 1.4 °C, 0.8 °C and 0.4 °C higher than that of asphalt mastics with SSF-PB, but not suitable for the evaluation of asphalt mastic contained SBS modified bitumen because of unique structure and performance of SBS.

  14. Initial Self-Healing Temperatures of Asphalt Mastics Based on Flow Behavior Index.

    Science.gov (United States)

    Li, Chao; Wu, Shaopeng; Tao, Guanyu; Xiao, Yue

    2018-05-29

    Increasing temperature is a simple and convenient method to accelerate the self-healing process of bitumen. However, bitumen may not achieve the healing capability at lower temperature, and may be aged if temperature is too high. In addition, the bitumen is mixed with mineral filler and formed as asphalt mastic in asphalt concrete, so it is more accurate to study the initial self-healing from the perspective of asphalt mastic. The primary purpose of this research was to examine the initial self-healing temperature of asphalt mastic, which was determined by the flow behavior index obtained from the flow characteristics. Firstly, the texture and geometry characteristics of two fillers were analyzed, and then the initial self-healing temperature of nine types of asphalt mastic, pure bitumen (PB) and styrene-butadiene-styrene (SBS) modified bitumen were determined by the flow behavior index. Results demonstrate that the average standard deviation of gray-scale texture value of limestone filler (LF) is 21.24% lower than that of steel slag filler (SSF), showing that the steel slag filler has a better particle distribution and geometry characteristics. Also the initial self-healing temperatures of asphalt mastics with 0.2, 0.4 and 0.6 LF-PB volume ratio are 46.5 °C, 47.2 °C and 49.4 °C, which are 1.4 °C, 0.8 °C and 0.4 °C higher than that of asphalt mastics with SSF-PB, but not suitable for the evaluation of asphalt mastic contained SBS modified bitumen because of unique structure and performance of SBS.

  15. Software

    Energy Technology Data Exchange (ETDEWEB)

    Macedo, R.; Budd, G.; Ross, E.; Wells, P.

    2010-07-15

    addition to a description of the software application, the name of software providers were listed along with the new features available in each product. The survey included products developed by ADP Inc.; Energy Navigator Inc.; Enersight Canada; Entero Corporation; Envirosoft Corporation; Geologic Systems Ltd.; IHS; Jedex Equipment Ltd.; MJ Systems; OpenSpirit; Petro Management Group Ltd.; P2 Energy Solutions; Risk Advisory, A division of SAS; Seisware International Inc.; Sustainet Software International Inc.; and 3ESI.

  16. Concept of software interface for BCI systems

    Science.gov (United States)

    Svejda, Jaromir; Zak, Roman; Jasek, Roman

    2016-06-01

    Brain Computer Interface (BCI) technology is intended to control external system by brain activity. One of main part of such system is software interface, which carries about clear communication between brain and either computer or additional devices connected to computer. This paper is organized as follows. Firstly, current knowledge about human brain is briefly summarized to points out its complexity. Secondly, there is described a concept of BCI system, which is then used to build an architecture of proposed software interface. Finally, there are mentioned disadvantages of sensing technology discovered during sensing part of our research.

  17. Verification and validation of control system software

    International Nuclear Information System (INIS)

    Munro, J.K. Jr.; Kisner, R.A.; Bhadtt, S.C.

    1991-01-01

    The following guidelines are proposed for verification and validation (V ampersand V) of nuclear power plant control system software: (a) use risk management to decide what and how much V ampersand V is needed; (b) classify each software application using a scheme that reflects what type and how much V ampersand V is needed; (c) maintain a set of reference documents with current information about each application; (d) use Program Inspection as the initial basic verification method; and (e) establish a deficiencies log for each software application. The following additional practices are strongly recommended: (a) use a computer-based configuration management system to track all aspects of development and maintenance; (b) establish reference baselines of the software, associated reference documents, and development tools at regular intervals during development; (c) use object-oriented design and programming to promote greater software reliability and reuse; (d) provide a copy of the software development environment as part of the package of deliverables; and (e) initiate an effort to use formal methods for preparation of Technical Specifications. The paper provides background information and reasons for the guidelines and recommendations. 3 figs., 3 tabs

  18. Software fault tolerance in computer operating systems

    Science.gov (United States)

    Iyer, Ravishankar K.; Lee, Inhwan

    1994-01-01

    This chapter provides data and analysis of the dependability and fault tolerance for three operating systems: the Tandem/GUARDIAN fault-tolerant system, the VAX/VMS distributed system, and the IBM/MVS system. Based on measurements from these systems, basic software error characteristics are investigated. Fault tolerance in operating systems resulting from the use of process pairs and recovery routines is evaluated. Two levels of models are developed to analyze error and recovery processes inside an operating system and interactions among multiple instances of an operating system running in a distributed environment. The measurements show that the use of process pairs in Tandem systems, which was originally intended for tolerating hardware faults, allows the system to tolerate about 70% of defects in system software that result in processor failures. The loose coupling between processors which results in the backup execution (the processor state and the sequence of events occurring) being different from the original execution is a major reason for the measured software fault tolerance. The IBM/MVS system fault tolerance almost doubles when recovery routines are provided, in comparison to the case in which no recovery routines are available. However, even when recovery routines are provided, there is almost a 50% chance of system failure when critical system jobs are involved.

  19. Honeywell Modular Automation System Computer Software Documentation

    International Nuclear Information System (INIS)

    CUNNINGHAM, L.T.

    1999-01-01

    This document provides a Computer Software Documentation for a new Honeywell Modular Automation System (MAS) being installed in the Plutonium Finishing Plant (PFP). This system will be used to control new thermal stabilization furnaces in HA-211 and vertical denitration calciner in HC-230C-2

  20. Software for managing multicrate FASTBUS Systems

    International Nuclear Information System (INIS)

    Deiss, S.R.; Gustavson, D.B.

    1982-10-01

    The FASTBUS System Manager software that was designed and implemented on an LSI-11 system using PASCAL is described. Particular attention is given to the file structures, file access mechanisms, and basic routing algorithms. Portability to other machines and languages is described

  1. Software Intensive Systems Cost and Schedule Estimation

    Science.gov (United States)

    2013-06-13

    of labor counted in or across each activity. The activity data in  the SRDR is reported following the [ ISO   12207 ] processes for software development...Release  Table 19 ISO /IEC 12207 Development Activities System requirements analysis System architectural design A ct iv iti es in S RD R da ta... 12207 ]  ISO /IEC  12207 , International Standard on Information Technology  Software Lifecycle Processes, International Organization for  Standardization

  2. Model-integrating software components engineering flexible software systems

    CERN Document Server

    Derakhshanmanesh, Mahdi

    2015-01-01

    In his study, Mahdi Derakhshanmanesh builds on the state of the art in modeling by proposing to integrate models into running software on the component-level without translating them to code. Such so-called model-integrating software exploits all advantages of models: models implicitly support a good separation of concerns, they are self-documenting and thus improve understandability and maintainability and in contrast to model-driven approaches there is no synchronization problem anymore between the models and the code generated from them. Using model-integrating components, software will be

  3. Improving Software Systems By Flow Control Analysis

    Directory of Open Access Journals (Sweden)

    Piotr Poznanski

    2012-01-01

    Full Text Available Using agile methods during the implementation of the system that meets mission critical requirements can be a real challenge. The change in the system built of dozens or even hundreds of specialized devices with embedded software requires the cooperation of a large group of engineers. This article presents a solution that supports parallel work of groups of system analysts and software developers. Deployment of formal rules to the requirements written in natural language enables using formal analysis of artifacts being a bridge between software and system requirements. Formalism and textual form of requirements allowed the automatic generation of message flow graph for the (sub system, called the “big-picture-model”. Flow diagram analysis helped to avoid a large number of defects whose repair cost in extreme cases could undermine the legitimacy of agile methods in projects of this scale. Retrospectively, a reduction of technical debt was observed. Continuous analysis of the “big picture model” improves the control of the quality parameters of the software architecture. The article also tries to explain why the commercial platform based on UML modeling language may not be sufficient in projects of this complexity.

  4. Consys Linear Control System Design Software Package

    International Nuclear Information System (INIS)

    Diamantidis, Z.

    1987-01-01

    This package is created in order to help engineers, researchers, students and all who work on linear control systems. The software includes all time and frequency domain analysises, spectral analysises and networks, active filters and regulators design aids. The programmes are written on Hewlett Packard computer in Basic 4.0

  5. Software for Intelligent System Health Management (ISHM)

    Science.gov (United States)

    Trevino, Luis C.

    2004-01-01

    The slide presentation is a briefing in four areas: overview of health management paradigms; overview of the ARC-Houston Software Engineering Technology Workshop held on April 20-22, 2004; identified technologies relevant to technical themes of intelligent system health management; and the author's thoughts on these topics.

  6. Software system for reducing PAM-2 data

    Science.gov (United States)

    Pepin, T. J.

    1982-01-01

    A software system for reducing PAM-II data was constructed. The data reduction process concatenates data tapes; determines ephemeris; and inverts full sun extinction data. Tests of this data reduction process show that PAM-II data can be compared with data from other, similar satellites.

  7. Hotel software-comprehensive hotel systems

    OpenAIRE

    Šilhová, Lenka

    2010-01-01

    This bachelor's thesis deals with the usage of computer systems in the hotel industry. First part is focused on history, development and integration of technology into this field. Second part is dedicated to concrete products of the company Micros-Fidelio, which is the leader of hotel software market in the Czech Republic.

  8. Hydraulically amplified self-healing electrostatic actuators with muscle-like performance

    Science.gov (United States)

    Acome, E.; Mitchell, S. K.; Morrissey, T. G.; Emmett, M. B.; Benjamin, C.; King, M.; Radakovitz, M.; Keplinger, C.

    2018-01-01

    Existing soft actuators have persistent challenges that restrain the potential of soft robotics, highlighting a need for soft transducers that are powerful, high-speed, efficient, and robust. We describe a class of soft actuators, termed hydraulically amplified self-healing electrostatic (HASEL) actuators, which harness a mechanism that couples electrostatic and hydraulic forces to achieve a variety of actuation modes. We introduce prototypical designs of HASEL actuators and demonstrate their robust, muscle-like performance as well as their ability to repeatedly self-heal after dielectric breakdown—all using widely available materials and common fabrication techniques. A soft gripper handling delicate objects and a self-sensing artificial muscle powering a robotic arm illustrate the wide potential of HASEL actuators for next-generation soft robotic devices.

  9. The microstructure of self-healed PVA ECC under wet and dry cycles

    Directory of Open Access Journals (Sweden)

    Jia Huan Yu

    2010-06-01

    Full Text Available Self-healing of ECC (Engineered Cementitious Composites subjected to cyclic wetting and drying regimes is investigated in this paper. ECC structures subjected to outdoor environmental conditions such as wind and rain runoff can be simulated by accelerated test method of wetting and drying cycles. Uniaxial tensile tests of ECC M45 and ECC 2.8FA specimen are conducted respectively. It is found that crack width of ECC 2.8FA is around 10 μm with increased amount of fly ash, while the crack width of ECC M45 is around 100 μm. New insights about the microstructure and chemical composition analysis of ECC specimens initially cracked to 2% strain and then self-healed under wet-dry cycles are presented.

  10. Synthesis of durable microcapsules for self-healing anticorrosive coatings: A comparison of selected methods

    DEFF Research Database (Denmark)

    Nesterova, Tatyana; Dam-Johansen, Kim; Kiil, Søren

    2011-01-01

    -based anticorrosive coatings, based on incorporation of microcapsules, filled with reactive agents, into the coating matrix, is investigated. Upon small damages to the coating, the reagents are released from the capsules and react, thereby forming a cross-linked network, which heals the crack. However......Self-healing materials have the ability to ‘repair’ themselves upon exposure to an external stimulus. In the field of coatings, extensive laboratory research has been conducted on these so-called smart materials in the last decade. In the present work, a self-healing concept for epoxy......, for the concept to work, microcapsules have to be strong enough to remain intact during storage and coating formulation and application. Furthermore, the capsules must remain stable for many years in the dry coating. Laboratory experiments, using four out of several encapsulation methods available...

  11. Repeated self-healing of microvascular carbon fibre reinforced polymer composites

    International Nuclear Information System (INIS)

    Coope, T S; Trask, R S; Bond, I P; Wass, D F

    2014-01-01

    A self-healing, high performance, carbon fibre reinforced polymer (CFRP) composite is demonstrated by embedding a Lewis-acid catalytic curing agent within a laminate, manufactured using out of autoclave (OOA) composite manufacturing methods. Two configurations of healing agent delivery, pre-mixed and autonomous mixing, are investigated via injection of a healing agent through bio-inspired microvascular channels exposed on Mode I fractured crack planes. Healing is effected when an epoxy resin-solvent healing agent mixture reaches the boundary of embedded solid-state scandium(III) triflate (Sc(OTf) 3 ) catalyst, located on the crack plane, to initiate the ring-opening polymerisation (ROP) of epoxides. Tailored self-healing agents confer high healing efficiency values after multiple healing cycles (69–108%) to successfully mitigate against crack propagation within the composite microstructure. (paper)

  12. Atomic Origins of the Self-Healing Function in Cement–Polymer Composites

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Manh Thuong; Wang, Zheming; Rod, Kenton A.; Childers, Matthew I.; Fernandez, Carlos A.; Koech, Phillip K.; Bennett, Wendy D.; Rousseau, Roger J.; Glezakou, Vassiliki-Alexandra

    2018-01-09

    Motivated by recent advances in self-healing cement and epoxy polymer composites, we present a combined ab initio molecular dynamics and sum frequency generation (SFG) spectroscopy study of a calcium-silicate-hydrate/polymer interface. On stable, low-defect surfaces, the polymer only weakly adheres through coordination and hydrogen bonding interactions and can be easily mobilized towards defected surfaces. Conversely, on fractured surfaces, the polymer strongly anchors through ionic Ca-O bonds resulting from the deprotonation of polymer hydroxyl groups. In addition, polymer S-S groups are turned away from the cement/polymer interface, allowing for the self-healing function within the polymer. The overall elasticity and healing properties of these composites stem from a flexible hydrogen bonding network that can readily adapt to surface morphology. The theoretical vibrational signals associated with the proposed cement-polymer interfacial chemistry were confirmed experimentally by SFG spectroscopy.

  13. Autonomous self-healing structural composites with bio-inspired design.

    Science.gov (United States)

    D'Elia, Eleonora; Eslava, Salvador; Miranda, Miriam; Georgiou, Theoni K; Saiz, Eduardo

    2016-05-05

    Strong and tough natural composites such as bone, silk or nacre are often built from stiff blocks bound together using thin interfacial soft layers that can also provide sacrificial bonds for self-repair. Here we show that it is possible exploit this design in order to create self-healing structural composites by using thin supramolecular polymer interfaces between ceramic blocks. We have built model brick-and-mortar structures with ceramic contents above 95 vol% that exhibit strengths of the order of MPa (three orders of magnitude higher than the interfacial polymer) and fracture energies that are two orders of magnitude higher than those of the glass bricks. More importantly, these properties can be fully recovered after fracture without using external stimuli or delivering healing agents. This approach demonstrates a very promising route towards the design of strong, ideal self-healing materials able to self-repair repeatedly without degradation or external stimuli.

  14. Recycling and Self-Healing of Polybenzoxazines with Dynamic Sulfide Linkages.

    Science.gov (United States)

    Arslan, Mustafa; Kiskan, Baris; Yagci, Yusuf

    2017-07-12

    In this work, a recycling and self-healing strategy for polybenzoxazines through both S-S bond cleavage-reformation reaction and supramolecular attractions is described. Both recyclable and self-healable polybenzoxazines can be prepared from low cost chemicals with a simple procedure in only 30 minutes. For this purpose, inverse vulcanization of poly(propylene oxide)benzoxazine (PPOB) and diallybenzoxazine (B-al) with elemental sulfur was performed at 185 °C. The obtained cross-linked polymer films exhibited thermally driven recycling ability up to 5 cycles. Moreover, the self-healing ability of a test specimen was shown. Spectral characterizations, thermal stability and fracture toughness of the films were investigated after each recycling.

  15. Reliable Software Development for Machine Protection Systems

    CERN Document Server

    Anderson, D; Dragu, M; Fuchsberger, K; Garnier, JC; Gorzawski, AA; Koza, M; Krol, K; Misiowiec, K; Stamos, K; Zerlauth, M

    2014-01-01

    The Controls software for the Large Hadron Collider (LHC) at CERN, with more than 150 millions lines of code, resides amongst the largest known code bases in the world1. Industry has been applying Agile software engineering techniques for more than two decades now, and the advantages of these techniques can no longer be ignored to manage the code base for large projects within the accelerator community. Furthermore, CERN is a particular environment due to the high personnel turnover and manpower limitations, where applying Agile processes can improve both, the codebase management as well as its quality. This paper presents the successful application of the Agile software development process Scrum for machine protection systems at CERN, the quality standards and infrastructure introduced together with the Agile process as well as the challenges encountered to adapt it to the CERN environment.

  16. Software challenges in extreme scale systems

    International Nuclear Information System (INIS)

    Sarkar, Vivek; Harrod, William; Snavely, Allan E

    2009-01-01

    Computer systems anticipated in the 2015 - 2020 timeframe are referred to as Extreme Scale because they will be built using massive multi-core processors with 100's of cores per chip. The largest capability Extreme Scale system is expected to deliver Exascale performance of the order of 10 18 operations per second. These systems pose new critical challenges for software in the areas of concurrency, energy efficiency and resiliency. In this paper, we discuss the implications of the concurrency and energy efficiency challenges on future software for Extreme Scale Systems. From an application viewpoint, the concurrency and energy challenges boil down to the ability to express and manage parallelism and locality by exploring a range of strong scaling and new-era weak scaling techniques. For expressing parallelism and locality, the key challenges are the ability to expose all of the intrinsic parallelism and locality in a programming model, while ensuring that this expression of parallelism and locality is portable across a range of systems. For managing parallelism and locality, the OS-related challenges include parallel scalability, spatial partitioning of OS and application functionality, direct hardware access for inter-processor communication, and asynchronous rather than interrupt-driven events, which are accompanied by runtime system challenges for scheduling, synchronization, memory management, communication, performance monitoring, and power management. We conclude by discussing the importance of software-hardware co-design in addressing the fundamental challenges for application enablement on Extreme Scale systems.

  17. Inkjet Assisted Creation of Self-Healing Layers Between Composite Plies

    Science.gov (United States)

    2013-07-29

    technology into a prepreg manufacturing process. The approach consisted of depositing novel thermoplastic low-viscosity microdroplets with chemically and...mechanically comparable properties to epoxy matrix in aerospace grade composites onto fiber-reinforced epoxy prepregs before curing using an ink-jet... prepreg Cycom977-2. Double cantilever beam (DCB) and short beam shear (SBS) tests were used to evaluate the self-healing efficiency. It was shown

  18. An autonomic self-healing organogel with a photo-mediated modulus

    KAUST Repository

    Xiong, Yubing

    2016-11-15

    A new method is described for fabricating autonomic, self-healing, deformable organogels. We combined imidazolium-based poly(ionic liquid) (PIL) and azobenzene-grafted poly(carboxylic acid) (PAA-Azo) in N,N-dimethyl formamide. Further, complexing PIL with unirradiated (trans) or irradiated (cis) PAA-Azo tuned the elastic modulus of the organogel. © 2016 The Royal Society of Chemistry.

  19. Self-Configuration and Self-Healing for Cognitive Optical Networks

    OpenAIRE

    Tronco, Tania Regina; Feres, Mariana Massimino; Cesar, Amilcar Careli; Rocha, Mônica de Lacerda

    2013-01-01

    In this article we propose a fuzzy controller, as an inference engine for cognitive optical networks, to take decisions about routing of new demands of lightpaths, considering physical layer impairments (Fuzzy Controlled-PLIARWA algorithm), selfconfiguration, self-healing and cross-layer optimization functionalities. The proposed algorithm has been tested in a metropolitan-scaled network. The preliminary results obtained are promising in terms of modularity, flexibility, ...

  20. An autonomic self-healing organogel with a photo-mediated modulus

    KAUST Repository

    Xiong, Yubing; Chen, Zhijun; Wang, Hong; Ackermann, Lisa Maria; Klapper, Markus; Butt, Hans Jü rgen; Wu, Si

    2016-01-01

    A new method is described for fabricating autonomic, self-healing, deformable organogels. We combined imidazolium-based poly(ionic liquid) (PIL) and azobenzene-grafted poly(carboxylic acid) (PAA-Azo) in N,N-dimethyl formamide. Further, complexing PIL with unirradiated (trans) or irradiated (cis) PAA-Azo tuned the elastic modulus of the organogel. © 2016 The Royal Society of Chemistry.

  1. Abalone water-soluble matrix for self-healing biomineralization of tooth defects

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Zhenliang [Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou 350002 (China); Chen, Jingdi, E-mail: ibptcjd@fzu.edu.cn [Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou 350002 (China); Wang, Hailiang [The Affiliated Stomatological Hospital, Fujian Medical University, Fuzhou 350002 (China); Zhong, Shengnan; Hu, Yimin; Wang, Zhili [Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou 350002 (China); Zhang, Qiqing, E-mail: zhangqiq@126.com [Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou 350002 (China); Institute of Biomedical Engineering, Chinese Academy of Medical Science & Peking Union Medical College, Tianjin 300192 (China)

    2016-10-01

    Enamel cannot heal by itself if damaged. Hydroxyapatite (HAP) is main component of human enamel. Formation of enamel-like materials for healing enamel defects remains a challenge. In this paper, we successfully isolated the abalone water-soluble matrix (AWSM) with 1.53 wt% the abalone water-soluble protein (AWSPro) and 2.04 wt% the abalone water-soluble polysaccharide (AWSPs) from abandoned abalone shell, and self-healing biomineralization of tooth defects was successfully achieved in vitro. Based on X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), hot field emission scanning electron microscopy (HFESEM) and energy dispersive spectrometer (EDS) analysis, the results showed that the AWSM can efficiently induce remineralization of HAP. The enamel-like HAP was successfully achieved onto etched enamel's surface due to the presence of the AWSM. Moreover, the remineralized effect of eroded enamel was growing with the increase of the AWSM. This study provides a solution to the resource waste and environmental pollution caused by abandoned abalone shell, and we provides a new method for self-healing remineralization of enamel defects by AWSM and develops a novel dental material for potential clinical dentistry application. - Graphical abstract: In this paper, we successfully isolated the abalone water-soluble matrix (AWSM) with 1.53 wt% abalone water-soluble protein (AWSPro) and 2.04 wt% abalone water-soluble polysaccharide (AWSPs) from abandoned abalone shell, and self-healing biomineralization of tooth defects was successfully achieved in vitro by self-organized. Display Omitted - Highlights: • Provides a solution to the resource waste and environmental pollution caused by abandoned abalone shell. • The abalone shell water-soluble matrix contains protein and polysaccharide. • The abalone water-soluble matrix can efficiently induce remineralization of HAP by self-organized. • Achieved self-healing biomineralization of tooth defects in

  2. Epithelial self-healing is recapitulated by a 3D biomimetic E-cadherin junction

    OpenAIRE

    Cohen, Daniel J.; Gloerich, Martijn; Nelson, W. James

    2016-01-01

    Epithelial monolayers undergo self-healing when wounded. During healing, cells collectively migrate into the wound site, and the converging tissue fronts collide and form a stable interface. To heal, migrating tissues must form cell-cell adhesions and reorganize from the front-rear polarity characteristic of cell migration to the apicalbasal polarity of an epithelium. However, identifying the "stop signal" that induces colliding tissues to cease migrating and heal remains an open question. Ep...

  3. Hydrophobic Light-to-Heat Conversion Membranes with Self-Healing Ability for Interfacial Solar Heating

    KAUST Repository

    Zhang, Lianbin

    2015-07-01

    Self-healing hydrophobic light-to-heat conversion membranes for interfacial solar heating are fabricated by deposition of light-to-heat conversion material of polypyrrole onto porous stainless steel mesh, followed by hydrophobic fluoroalkylsilane modification. The mesh-based membranes spontaneously stay at the water–air interface, collect and convert solar light into heat, and locally heat only the water surface for an enhanced evaporation.

  4. Hydrophobic Light-to-Heat Conversion Membranes with Self-Healing Ability for Interfacial Solar Heating

    KAUST Repository

    Zhang, Lianbin; Tang, Bo; Wu, Jinbo; Li, Renyuan; Wang, Peng

    2015-01-01

    Self-healing hydrophobic light-to-heat conversion membranes for interfacial solar heating are fabricated by deposition of light-to-heat conversion material of polypyrrole onto porous stainless steel mesh, followed by hydrophobic fluoroalkylsilane modification. The mesh-based membranes spontaneously stay at the water–air interface, collect and convert solar light into heat, and locally heat only the water surface for an enhanced evaporation.

  5. Abalone water-soluble matrix for self-healing biomineralization of tooth defects

    International Nuclear Information System (INIS)

    Wen, Zhenliang; Chen, Jingdi; Wang, Hailiang; Zhong, Shengnan; Hu, Yimin; Wang, Zhili; Zhang, Qiqing

    2016-01-01

    Enamel cannot heal by itself if damaged. Hydroxyapatite (HAP) is main component of human enamel. Formation of enamel-like materials for healing enamel defects remains a challenge. In this paper, we successfully isolated the abalone water-soluble matrix (AWSM) with 1.53 wt% the abalone water-soluble protein (AWSPro) and 2.04 wt% the abalone water-soluble polysaccharide (AWSPs) from abandoned abalone shell, and self-healing biomineralization of tooth defects was successfully achieved in vitro. Based on X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), hot field emission scanning electron microscopy (HFESEM) and energy dispersive spectrometer (EDS) analysis, the results showed that the AWSM can efficiently induce remineralization of HAP. The enamel-like HAP was successfully achieved onto etched enamel's surface due to the presence of the AWSM. Moreover, the remineralized effect of eroded enamel was growing with the increase of the AWSM. This study provides a solution to the resource waste and environmental pollution caused by abandoned abalone shell, and we provides a new method for self-healing remineralization of enamel defects by AWSM and develops a novel dental material for potential clinical dentistry application. - Graphical abstract: In this paper, we successfully isolated the abalone water-soluble matrix (AWSM) with 1.53 wt% abalone water-soluble protein (AWSPro) and 2.04 wt% abalone water-soluble polysaccharide (AWSPs) from abandoned abalone shell, and self-healing biomineralization of tooth defects was successfully achieved in vitro by self-organized. Display Omitted - Highlights: • Provides a solution to the resource waste and environmental pollution caused by abandoned abalone shell. • The abalone shell water-soluble matrix contains protein and polysaccharide. • The abalone water-soluble matrix can efficiently induce remineralization of HAP by self-organized. • Achieved self-healing biomineralization of tooth defects in vitro.

  6. Multi-Level Formation of Complex Software Systems

    Directory of Open Access Journals (Sweden)

    Hui Li

    2016-05-01

    Full Text Available We present a multi-level formation model for complex software systems. The previous works extract the software systems to software networks for further studies, but usually investigate the software networks at the class level. In contrast to these works, our treatment of software systems as multi-level networks is more realistic. In particular, the software networks are organized by three levels of granularity, which represents the modularity and hierarchy in the formation process of real-world software systems. More importantly, simulations based on this model have generated more realistic structural properties of software networks, such as power-law, clustering and modularization. On the basis of this model, how the structure of software systems effects software design principles is then explored, and it could be helpful for understanding software evolution and software engineering practices.

  7. Vision for a self-healing power grid

    Energy Technology Data Exchange (ETDEWEB)

    Moslehi, Khosrow; Kumar, Ranjit

    2007-07-01

    Power system reliability has been thrust into the limelight by recent blackouts around the world. The social and economic costs of these failures can add up to billions of dollars every year. As the digital age prevails, more efficient manufacturing processes, based on computers and power electronics, have come to dominate industry. As the portion of electricity in the total energy consumption continues to grow, the value of power system reliability increases. This article discusses a vision for state-of-the-art solutions to improve power system reliability through improved monitoring and control. (auth)

  8. Software Defined Common Processing System (SDCPS), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Coherent Logix, Incorporated proposes the Software Defined Common Processing System (SDCPS) program to facilitate the development of a Software Defined Radio...

  9. Bio-reinforced self-healing concrete using magnetic iron oxide nanoparticles.

    Science.gov (United States)

    Seifan, Mostafa; Sarmah, Ajit K; Ebrahiminezhad, Alireza; Ghasemi, Younes; Samani, Ali Khajeh; Berenjian, Aydin

    2018-03-01

    Immobilization has been reported as an efficient technique to address the bacterial vulnerability for application in bio self-healing concrete. In this study, for the first time, magnetic iron oxide nanoparticles (IONs) are being practically employed as the protective vehicle for bacteria to evaluate the self-healing performance in concrete environment. Magnetic IONs were successfully synthesized and characterized using different techniques. The scanning electron microscope (SEM) images show the efficient adsorption of nanoparticles to the Bacillus cells. Microscopic observation illustrates that the incorporation of the immobilized bacteria in the concrete matrix resulted in a significant crack healing behavior, while the control specimen had no healing characteristics. Analysis of bio-precipitates revealed that the induced minerals in the cracks were calcium carbonate. The effect of magnetic immobilized cells on the concrete water absorption showed that the concrete specimens supplemented with decorated bacteria with IONs had a higher resistance to water penetration. The initial and secondary water absorption rates in bio-concrete specimens were 26% and 22% lower than the control specimens. Due to the compatible behavior of IONs with the concrete compositions, the results of this study proved the potential application of IONs for developing a new generation of bio self-healing concrete.

  10. Fracturing and Self-Healing in the Boom Clay: Evidences and Further Studies

    International Nuclear Information System (INIS)

    Bernier, Frederic

    2001-01-01

    The Boom Clay is considered as a potential host-rock for the disposal of Belgian radioactive waste. During the sinking of a new shaft to extend the underground facility HADES, an important fracturing has been evidenced around the excavation. Fracturing was already observed previously but to a lesser extent. The low support pressure imposed by the primary shaft lining, combined with the large time over which this support condition held, has favoured the decompression of the clay massif through delayed effects, and therefore the development of fracturing. In the frame of the overall performance of a radioactive waste repository, it is of prime importance to understand the fracturing process induced by excavation in Boom Clay, as well as the self-healing process. Some self-healing evidences have been observed around the HADES underground laboratory but need further investigation to be confirmed. This will be done in the SELFRAC EC project (Fractures and Self-healing within the Excavation Disturbed Zone in clays)

  11. Biomimetic Self-Organization and Self-Healing

    DEFF Research Database (Denmark)

    Lenau, Torben Anker; Hesselberg, Thomas

    2013-01-01

    of the important role of biophysics. Some physical applications include adhesion superhydrophobicity and self-cleaning, structural coloration, photonic devices, biomaterials and composite materials, sensor systems, robotics and locomotion, and ultra-lightweight structures. Explores biomimicry, a fast...... and vision sensors, Engineered Biomimicry explores a wide range of technologies informed by living natural systems. Engineered Biomimicry helps physicists, engineers and material scientists seek solutions in nature to the most pressing technical problems of our times, while providing a solid understanding...

  12. Self-healing phenomena in cement-based materials state-of-the-art report of RILEM Technical Committee 221-SHC Self-Healing Phenomena in Cement-Based Materials

    CERN Document Server

    Tittelboom, Kim; Belie, Nele; Schlangen, Erik

    2013-01-01

    Self-healing materials are man-made materials which have the built-in capability to repair damage. Failure in materials is often caused by the occurrence of small microcracks throughout the material. In self-healing materials phenomena are triggered to counteract these microcracks. These processes are ideally triggered by the occurrence of damage itself. Thus far, the self-healing capacity of cement-based materials has been considered as something "extra". This could be called passive self-healing, since it was not a designed feature of the material, but an inherent property of it. Centuries-old buildings have been said to have survived these centuries because of the inherent self-healing capacity of the binders used for cementing building blocks together. In this State-of-the-Art Report a closer look is taken at self-healing phenomena in cement-based materials. It is shown what options are available to design for this effect rather than have it occur as a "coincidental extra".

  13. Architecture of a software quench management system

    International Nuclear Information System (INIS)

    Jerzy M. Nogiec et al.

    2001-01-01

    Testing superconducting accelerator magnets is inherently coupled with the proper handling of quenches; i.e., protecting the magnet and characterizing the quench process. Therefore, software implementations must include elements of both data acquisition and real-time controls. The architecture of the quench management software developed at Fermilab's Magnet Test Facility is described. This system consists of quench detection, quench protection, and quench characterization components that execute concurrently in a distributed system. Collaboration between the elements of quench detection, quench characterization and current control are discussed, together with a schema of distributed saving of various quench-related data. Solutions to synchronization and reliability in such a distributed quench system are also presented

  14. Timing system control software in the SLC

    International Nuclear Information System (INIS)

    Thompson, K.; Phinney, N.

    1985-04-01

    A new timing system that allows precision (approx.1 to 2 ns) control of the trigger times of klystrons, beam position monitors, and other devices on a pulse-to-pulse basis at up to 360 Hz is in operation in the first third of the SLAC linear accelerator. The control software is divided between a central host VAX and local Intel 8086-based microprocessor clusters. Facilities exist to set up and adjust the timing of devices or groups of devices independently for beam pulses having different destinations and purposes, which are run in an interlaced fashion during normal machine operation. Upgrading of the system is currently underway, using a new version of the Programmable Delay Unit CAMAC module to allow pipelining of timing information for three machine pulses. An overview of the current state of the system is presented in this paper, with an emphasis on software control

  15. Self-healing liquid/solid state battery

    Science.gov (United States)

    Burke, Paul J.; Chung, Brice H.V.; Phadke, Satyajit R.; Ning, Xiaohui; Sadoway, Donald R.

    2018-02-27

    A battery system that exchanges energy with an external device is provided. The battery system includes a positive electrode having a first metal or alloy, a negative electrode having a second metal or alloy, and an electrolyte including a salt of the second metal or alloy. The positive electrode, the negative electrode, and the electrolyte are in a liquid phase at an operating temperature during at least one portion of operation. The positive electrode is entirely in a liquid phase in one charged state and includes a solid phase in another charged state. The solid phase of the positive electrode includes a solid intermetallic formed by the first and the second metals or alloys. Methods of storing electrical energy from an external circuit using such a battery system are also provided.

  16. Self-healing of quantum entanglement after an obstruction

    CSIR Research Space (South Africa)

    McLaren, M

    2014-02-01

    Full Text Available Quantum entanglement between photon pairs is fragile and can easily be masked by losses in transmission path and noise in the detection system. When observing the quantum entanglement between the spatial states of photon pairs produced by parametric...

  17. A Study on the Manufacturing Properties of Crack Self-Healing Capsules Using Cement Powder for Addition to Cement Composites

    OpenAIRE

    Choi, Yun-Wang; Oh, Sung-Rok; Choi, Byung-Keol

    2017-01-01

    We fabricated crack self-healing capsules using cement powder for mixing into cement composites and evaluated the properties of the capsule manufacturing process in this study. The manufacture of the self-healing capsules is divided into core production processing of granulating cement in powder form and a coating process for creating a wall on the surfaces of the granulated cement particles. The produced capsules contain unhardened cement and can be mixed directly with the cement composite m...

  18. Active self-healing encapsulation of vaccine antigens in PLGA microspheres

    Science.gov (United States)

    Desai, Kashappa-Goud H.; Schwendeman, Steven P.

    2013-01-01

    Herein, we describe the detailed development of a simple and effective method to microencapsulate vaccine antigens in poly(lactic-co-glycolic acid) (PLGA) by simple mixing of preformed active self-microencapsulating (SM) PLGA microspheres in a low concentration aqueous antigen solution at modest temperature (10-38 °C). Co-encapsulating protein-sorbing vaccine adjuvants and polymer plasticizers were used to “actively” load the protein in the polymer pores and facilitate polymer self-healing at temperature > hydrated polymer glass transition temperature, respectively. The microsphere formulation parameters and loading conditions to provide optimal active self-healing microencapsulation of vaccine antigen in PLGA was investigated. Active self-healing encapsulation of two vaccine antigens, ovalbumin and tetanus toxoid (TT), in PLGA microspheres was adjusted by preparing blank microspheres containing different vaccine adjuvant (aluminum hydroxide (Al(OH)3) or calcium phosphate). Active loading of vaccine antigen in Al(OH)3-PLGA microspheres was found to: a) increase proportionally with an increasing loading of Al(OH)3 (0.88-3 wt%) and addition of porosigen, b) decrease when the inner Al(OH)3/trehalose phase to 1 mL outer oil phase and size of microspheres was respectively > 0.2 mL and 63 μm, and c) change negligibly by PLGA concentration and initial incubation (loading) temperature. Encapsulation of protein sorbing Al(OH)3 in PLGA microspheres resulted in suppression of self-healing of PLGA pores, which was then overcome by improving polymer chain mobility, which in turn was accomplished by coincorporating hydrophobic plasticizers in PLGA. Active self-healing microencapsulation of manufacturing process-labile TT in PLGA was found to: a) obviate micronization- and organic solvent-induced TT degradation, b) improve antigen loading (1.4-1.8 wt% TT) and encapsulation efficiency (~ 97%), c) provide nearly homogeneous distribution and stabilization of antigen in polymer

  19. A software Event Summation System for MDSplus

    International Nuclear Information System (INIS)

    Davis, W.M.; Mastrovito, D.M.; Roney, P.G.; Sichta, P.

    2008-01-01

    The MDSplus data acquisition and management system uses software events for communication among interdependent processes anywhere on the network. Actions can then be triggered, such as a data-acquisition routine, or analysis or display programs waiting for data. A small amount of data, such as a shot number, can be passed with these events. Since programs sometimes need more than one data set, we developed a system on NSTX to declare composite events using logical AND and OR operations. The system is written in the IDL language, so it can be run on Linux, Macintosh or Windows platforms. Like MDSplus, the Experimental Physics and Industrial Control System (EPICS) is a core component of the NSTX software environment. The Event Summation System provides an IDL-based interface to EPICS. This permits EPICS-aware processes to be synchronized with MDSplus-aware processes, to provide, for example, engineering operators information about physics data acquisition and analysis. Reliability was a more important design consideration than performance for this system; the system's architecture includes features to support this. The system has run for weeks at a time without requiring manual intervention. Hundreds of incoming events per second can be handled reliably. All incoming and declared events are logged with a timestamp. The system can be configured easily through a single, easy-to-read text file

  20. Software quality assurance and software safety in the Biomed Control System

    International Nuclear Information System (INIS)

    Singh, R.P.; Chu, W.T.; Ludewigt, B.A.; Marks, K.M.; Nyman, M.A.; Renner, T.R.; Stradtner, R.

    1989-01-01

    The Biomed Control System is a hardware/software system used for the delivery, measurement and monitoring of heavy-ion beams in the patient treatment and biology experiment rooms in the Bevalac at the Lawrence Berkeley Laboratory (LBL). This paper describes some aspects of this system including historical background philosophy, configuration management, hardware features that facilitate software testing, software testing procedures, the release of new software quality assurance, safety and operator monitoring. 3 refs

  1. Self-healing bolted joint employing a shape memory actuator

    Science.gov (United States)

    Muntges, Daniel E.; Park, Gyuhae; Inman, Daniel J.

    2001-08-01

    This paper is a report of an initial investigation into the active control of preload in the joint using a shape memory actuator around the axis of the bolt shaft. Specifically, the actuator is a cylindrical Nitinol washer that expands axially when heated, according to the shape memory effect. The washer is actuated in response to an artificial decrease in torque. Upon actuation, the stress generated by its axial strain compresses the bolted members and creates a frictional force that has the effect of generating a preload and restoring lost torque. In addition to torque wrenches, the system in question was monitored in all stages of testing using piezoelectric impedance analysis. Impedance analysis drew upon research techniques developed at Center for Intelligent Material Systems and Structures, in which phase changes in the impedance of a self-sensing piezoceramic actuator correspond to changes in joint stiffness. Through experimentation, we have documented a successful actuation of the shape memory element. Due to complexity of constitutive modeling, qualitative analysis by the impedance method is used to illustrate the success. Additional considerations encountered in this initial investigation are made to guide further thorough research required for the successful commercial application of this promising technique.

  2. Self-Healing Many-Core Architecture: Analysis and Evaluation

    Directory of Open Access Journals (Sweden)

    Arezoo Kamran

    2016-01-01

    Full Text Available More pronounced aging effects, more frequent early-life failures, and incomplete testing and verification processes due to time-to-market pressure in new fabrication technologies impose reliability challenges on forthcoming systems. A promising solution to these reliability challenges is self-test and self-reconfiguration with no or limited external control. In this work a scalable self-test mechanism for periodic online testing of many-core processor has been proposed. This test mechanism facilitates autonomous detection and omission of faulty cores and makes graceful degradation of the many-core architecture possible. Several test components are incorporated in the many-core architecture that distribute test stimuli, suspend normal operation of individual processing cores, apply test, and detect faulty cores. Test is performed concurrently with the system normal operation without any noticeable downtime at the application level. Experimental results show that the proposed test architecture is extensively scalable in terms of hardware overhead and performance overhead that makes it applicable to many-cores with more than a thousand processing cores.

  3. Software for airborne radiation monitoring system

    International Nuclear Information System (INIS)

    Sheinfeld, M.; Kadmon, Y.; Tirosh, D.; Elhanany, I.; Gabovitch, A.; Barak, D.

    1997-01-01

    The Airborne Radiation Monitoring System monitors radioactive contamination in the air or on the ground. The contamination source can be a radioactive plume or an area contaminated with radionuclides. This system is composed of two major parts: Airborne Unit carried by a helicopter, and Ground Station carried by a truck. The Airborne software is intended to be the core of a computerized airborne station. The software is written in C++ under MS-Windows with object-oriented methodology. It has been designed to be user-friendly: function keys and other accelerators are used for vital operations, a help file and help subjects are available, the Human-Machine-Interface is plain and obvious. (authors)

  4. Novel software system development for finance

    OpenAIRE

    Maad, Soha

    2002-01-01

    This paper addresses the need for novel software system development (SSD) practices in finance. It proposes Empirical Modelling as a novel approach for SSD in finance. This approach aims at finding a suitable framework for studying both the traditional and the emerging computing culture to SSD in finance. First, the paper studies the change in the financial industry and identifies key issues of the application of computer-based technology in finance. These key issues are framed in a wider age...

  5. Creating the next generation control system software

    International Nuclear Information System (INIS)

    Schultz, D.E.

    1989-01-01

    A new 1980's style support package for future accelerator control systems is proposed. It provides a way to create accelerator applications software without traditional programming. Visual Interactive Applications (VIA) is designed to meet the needs of expanded accelerator complexes in a more cost effective way than past experience with procedural languages by using technology from the personal computer and artificial intelligence communities. 4 refs

  6. A hybrid optic-fiber sensor network with the function of self-diagnosis and self-healing

    Science.gov (United States)

    Xu, Shibo; Liu, Tiegen; Ge, Chunfeng; Chen, Cheng; Zhang, Hongxia

    2014-11-01

    We develop a hybrid wavelength division multiplexing optical fiber network with distributed fiber-optic sensors and quasi-distributed FBG sensor arrays which detect vibrations, temperatures and strains at the same time. The network has the ability to locate the failure sites automatically designated as self-diagnosis and make protective switching to reestablish sensing service designated as self-healing by cooperative work of software and hardware. The processes above are accomplished by master-slave processors with the help of optical and wireless telemetry signals. All the sensing and optical telemetry signals transmit in the same fiber either working fiber or backup fiber. We take wavelength 1450nm as downstream signal and wavelength 1350nm as upstream signal to control the network in normal circumstances, both signals are sent by a light emitting node of the corresponding processor. There is also a continuous laser wavelength 1310nm sent by each node and received by next node on both working and backup fibers to monitor their healthy states, but it does not carry any message like telemetry signals do. When fibers of two sensor units are completely damaged, the master processor will lose the communication with the node between the damaged ones.However we install RF module in each node to solve the possible problem. Finally, the whole network state is transmitted to host computer by master processor. Operator could know and control the network by human-machine interface if needed.

  7. MATLAB Software Versions and Licenses for the Peregrine System |

    Science.gov (United States)

    High-Performance Computing | NREL MATLAB Software Versions and Licenses for the Peregrine System MATLAB Software Versions and Licenses for the Peregrine System Learn about the MATLAB software Peregrine is R2017b. Licenses MATLAB is proprietary software. As such, users have access to a limited number

  8. Ground test accelerator control system software

    International Nuclear Information System (INIS)

    Burczyk, L.; Dalesio, R.; Dingler, R.; Hill, J.; Howell, J.A.; Kerstiens, D.; King, R.; Kozubal, A.; Little, C.; Martz, V.; Rothrock, R.; Sutton, J.

    1988-01-01

    This paper reports on the GTA control system that provides an environment in which the automation of a state-of-the-art accelerator can be developed. It makes use of commercially available computers, workstations, computer networks, industrial 110 equipment, and software. This system has built-in supervisory control (like most accelerator control systems), tools to support continuous control (like the process control industry), and sequential control for automatic start-up and fault recovery (like few other accelerator control systems). Several software tools support these levels of control: a real-time operating system (VxWorks) with a real-time kernel (VRTX), a configuration database, a sequencer, and a graphics editor. VxWorks supports multitasking, fast context-switching, and preemptive scheduling. VxWorks/VRTX is a network-based development environment specifically designed to work in partnership with the UNIX operating system. A data base provides the interface to the accelerator components. It consists of a run time library and a database configuration and editing tool. A sequencer initiates and controls the operation of all sequence programs (expressed as state programs). A graphics editor gives the user the ability to create color graphic displays showing the state of the machine in either text or graphics form

  9. Application software for new BEPC interlock system

    International Nuclear Information System (INIS)

    Tang Shuming; Na Xiangyin; Chen Jiansong; Yu Yulan

    1997-01-01

    New BEPC (Beijing electron Positron collider) interlock system has been built in order to improve the reliability of personnel safety and interlock functions. Moreover, the system updates BEPC operation message once every 6 seconds, which are displayed on TV screens at the major entrances. Since March of 1996, new BEPC interlock system has been operating reliably. The hardware of the system is based on Programmable Logic Controllers (PLC). A multimedia IBM/PC-586 as the host computer of the PLCs, monitors the PLC system via serial port COM2. The PC communicates with the central computer VAX-4500 of BEPC control system and gets operating massage of the accelerator through serial port COM3. The application software on the host computer has been developed. Visual C++ for MS-Windows 3.2 TM is selected as the work bench. It provides nice tools for building programs, such as APP STUDIO, CLASS WIZARD, APP WIZARD and debugger tool. The author describes the design idea and the structure of the application software. Error tolerance is taken into consideration. The author also presents a small database and its data structure for the application

  10. Integrating existing software toolkits into VO system

    Science.gov (United States)

    Cui, Chenzhou; Zhao, Yong-Heng; Wang, Xiaoqian; Sang, Jian; Luo, Ze

    2004-09-01

    Virtual Observatory (VO) is a collection of interoperating data archives and software tools. Taking advantages of the latest information technologies, it aims to provide a data-intensively online research environment for astronomers all around the world. A large number of high-qualified astronomical software packages and libraries are powerful and easy of use, and have been widely used by astronomers for many years. Integrating those toolkits into the VO system is a necessary and important task for the VO developers. VO architecture greatly depends on Grid and Web services, consequently the general VO integration route is "Java Ready - Grid Ready - VO Ready". In the paper, we discuss the importance of VO integration for existing toolkits and discuss the possible solutions. We introduce two efforts in the field from China-VO project, "gImageMagick" and "Galactic abundance gradients statistical research under grid environment". We also discuss what additional work should be done to convert Grid service to VO service.

  11. Software Engineering and Swarm-Based Systems

    Science.gov (United States)

    Hinchey, Michael G.; Sterritt, Roy; Pena, Joaquin; Rouff, Christopher A.

    2006-01-01

    We discuss two software engineering aspects in the development of complex swarm-based systems. NASA researchers have been investigating various possible concept missions that would greatly advance future space exploration capabilities. The concept mission that we have focused on exploits the principles of autonomic computing as well as being based on the use of intelligent swarms, whereby a (potentially large) number of similar spacecraft collaborate to achieve mission goals. The intent is that such systems not only can be sent to explore remote and harsh environments but also are endowed with greater degrees of protection and longevity to achieve mission goals.

  12. The VAXONLINE software system at Fermilab

    International Nuclear Information System (INIS)

    White, V.; Heinicke, P.; Berman, E.

    1987-06-01

    The VAXONLINE software system, started in late 1984, is now in use at 12 experiments at Fermilab, with at least one VAX or MicroVax. Data acquisition features now provide for the collection and combination of data from one or more sources, via a list-driven Event Builder program. Supported sources include CAMAC, FASTBUS, Front-end PDP-11's, Disk, Tape, DECnet, and other processors running VAXONLINE. This paper describes the functionality provided by the VAXONLINE system, gives performance figures, and discusses the ongoing program of enhancements

  13. Digital PIV (DPIV) Software Analysis System

    Science.gov (United States)

    Blackshire, James L.

    1997-01-01

    A software package was developed to provide a Digital PIV (DPIV) capability for NASA LaRC. The system provides an automated image capture, test correlation, and autocorrelation analysis capability for the Kodak Megaplus 1.4 digital camera system for PIV measurements. The package includes three separate programs that, when used together with the PIV data validation algorithm, constitutes a complete DPIV analysis capability. The programs are run on an IBM PC/AT host computer running either Microsoft Windows 3.1 or Windows 95 using a 'quickwin' format that allows simple user interface and output capabilities to the windows environment.

  14. The architecture of a reliable software monitoring system for embedded software systems

    International Nuclear Information System (INIS)

    Munson, J.; Krings, A.; Hiromoto, R.

    2006-01-01

    We develop the notion of a measurement-based methodology for embedded software systems to ensure properties of reliability, survivability and security, not only under benign faults but under malicious and hazardous conditions as well. The driving force is the need to develop a dynamic run-time monitoring system for use in these embedded mission critical systems. These systems must run reliably, must be secure and they must fail gracefully. That is, they must continue operating in the face of the departures from their nominal operating scenarios, the failure of one or more system components due to normal hardware and software faults, as well as malicious acts. To insure the integrity of embedded software systems, the activity of these systems must be monitored as they operate. For each of these systems, it is possible to establish a very succinct representation of nominal system activity. Furthermore, it is possible to detect departures from the nominal operating scenario in a timely fashion. Such departure may be due to various circumstances, e.g., an assault from an outside agent, thus forcing the system to operate in an off-nominal environment for which it was neither tested nor certified, or a hardware/software component that has ceased to operate in a nominal fashion. A well-designed system will have the property of graceful degradation. It must continue to run even though some of the functionality may have been lost. This involves the intelligent re-mapping of system functions. Those functions that are impacted by the failure of a system component must be identified and isolated. Thus, a system must be designed so that its basic operations may be re-mapped onto system components still operational. That is, the mission objectives of the software must be reassessed in terms of the current operational capabilities of the software system. By integrating the mechanisms to support observation and detection directly into the design methodology, we propose to shift

  15. Resilience Engineering in Critical Long Term Aerospace Software Systems: A New Approach to Spacecraft Software Safety

    Science.gov (United States)

    Dulo, D. A.

    Safety critical software systems permeate spacecraft, and in a long term venture like a starship would be pervasive in every system of the spacecraft. Yet software failure today continues to plague both the systems and the organizations that develop them resulting in the loss of life, time, money, and valuable system platforms. A starship cannot afford this type of software failure in long journeys away from home. A single software failure could have catastrophic results for the spaceship and the crew onboard. This paper will offer a new approach to developing safe reliable software systems through focusing not on the traditional safety/reliability engineering paradigms but rather by focusing on a new paradigm: Resilience and Failure Obviation Engineering. The foremost objective of this approach is the obviation of failure, coupled with the ability of a software system to prevent or adapt to complex changing conditions in real time as a safety valve should failure occur to ensure safe system continuity. Through this approach, safety is ensured through foresight to anticipate failure and to adapt to risk in real time before failure occurs. In a starship, this type of software engineering is vital. Through software developed in a resilient manner, a starship would have reduced or eliminated software failure, and would have the ability to rapidly adapt should a software system become unstable or unsafe. As a result, long term software safety, reliability, and resilience would be present for a successful long term starship mission.

  16. Data acquisition and test system software

    International Nuclear Information System (INIS)

    Bourgeois, N.A. Jr.

    1979-03-01

    Sandia Laboratories has been assigned the task by the Base and Installation Security Systems (BISS) Program Office to develop various aspects of perimeter security systems. One part of this effort involves the development of advanced signal processing techniques to reduce the false and nuisance alarms from sensor systems while improving the probability of intrusion detection. The need existed for both data acquisition hardware and software. Also, the hardware is used to implement and test the signal processing algorithms in real time. The hardware developed for this signal processing task is the Data Acquisition and Test System (DATS). The programs developed for use on DATS are described. The descriptions are taken directly from the documentation included within the source programs themselves

  17. Software Design Methods for Real-Time Systems

    Science.gov (United States)

    1989-12-01

    This module describes the concepts and methods used in the software design of real time systems . It outlines the characteristics of real time systems , describes...the role of software design in real time system development, surveys and compares some software design methods for real - time systems , and

  18. 14 CFR 417.123 - Computing systems and software.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Computing systems and software. 417.123... systems and software. (a) A launch operator must document a system safety process that identifies the... systems and software. (b) A launch operator must identify all safety-critical functions associated with...

  19. Data systems and computer science: Software Engineering Program

    Science.gov (United States)

    Zygielbaum, Arthur I.

    1991-01-01

    An external review of the Integrated Technology Plan for the Civil Space Program is presented. This review is specifically concerned with the Software Engineering Program. The goals of the Software Engineering Program are as follows: (1) improve NASA's ability to manage development, operation, and maintenance of complex software systems; (2) decrease NASA's cost and risk in engineering complex software systems; and (3) provide technology to assure safety and reliability of software in mission critical applications.

  20. The SOFIA Mission Control System Software

    Science.gov (United States)

    Heiligman, G. M.; Brock, D. R.; Culp, S. D.; Decker, P. H.; Estrada, J. C.; Graybeal, J. B.; Nichols, D. M.; Paluzzi, P. R.; Sharer, P. J.; Pampell, R. J.; Papke, B. L.; Salovich, R. D.; Schlappe, S. B.; Spriestersbach, K. K.; Webb, G. L.

    1999-05-01

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) will be delivered with a computerized mission control system (MCS). The MCS communicates with the aircraft's flight management system and coordinates the operations of the telescope assembly, mission-specific subsystems, and the science instruments. The software for the MCS must be reliable and flexible. It must be easily usable by many teams of observers with widely differing needs, and it must support non-intrusive access for education and public outreach. The technology must be appropriate for SOFIA's 20-year lifetime. The MCS software development process is an object-oriented, use case driven approach. The process is iterative: delivery will be phased over four "builds"; each build will be the result of many iterations; and each iteration will include analysis, design, implementation, and test activities. The team is geographically distributed, coordinating its work via Web pages, teleconferences, T.120 remote collaboration, and CVS (for Internet-enabled configuration management). The MCS software architectural design is derived in part from other observatories' experience. Some important features of the MCS are: * distributed computing over several UNIX and VxWorks computers * fast throughput of time-critical data * use of third-party components, such as the Adaptive Communications Environment (ACE) and the Common Object Request Broker Architecture (CORBA) * extensive configurability via stored, editable configuration files * use of several computer languages so developers have "the right tool for the job". C++, Java, scripting languages, Interactive Data Language (from Research Systems, Int'l.), XML, and HTML will all be used in the final deliverables. This paper reports on work in progress, with the final product scheduled for delivery in 2001. This work was performed for Universities Space Research Association for NASA under contract NAS2-97001.

  1. 78 FR 47015 - Software Requirement Specifications for Digital Computer Software Used in Safety Systems of...

    Science.gov (United States)

    2013-08-02

    ... NUCLEAR REGULATORY COMMISSION [NRC-2012-0195] Software Requirement Specifications for Digital Computer Software Used in Safety Systems of Nuclear Power Plants AGENCY: Nuclear Regulatory Commission... issuing a revised regulatory guide (RG), revision 1 of RG 1.172, ``Software Requirement Specifications for...

  2. Bioinspired engineering study of Plantae vascules for self-healing composite structures

    Science.gov (United States)

    Trask, R. S.; Bond, I. P.

    2010-01-01

    This paper presents the first conceptual study into creating a Plantae-inspired vascular network within a fibre-reinforced polymer composite laminate, which provides an ongoing self-healing functionality without incurring a mass penalty. Through the application of a ‘lost-wax’ technique, orthogonal hollow vascules, inspired by the ‘ray cell’ structures found in ring porous hardwoods, were successfully introduced within a carbon fibre-reinforced epoxy polymer composite laminate. The influence on fibre architecture and mechanical behaviour of single vascules (located on the laminate centreline) when aligned parallel and transverse to the local host ply was characterized experimentally using a compression-after-impact test methodology. Ultrasonic C-scanning and high-resolution micro-CT X-ray was undertaken to identify the influence of and interaction between the internal vasculature and impact damage. The results clearly show that damage morphology is influenced by vascule orientation and that a 10 J low-velocity impact damage event is sufficient to breach the vasculature; a prerequisite for any subsequent self-healing function. The residual compressive strength after a 10 J impact was found to be dependent upon vascule orientation. In general, residual compressive strength decreased to 70 per cent of undamaged strength when vasculature was aligned parallel to the local host ply and a value of 63 per cent when aligned transverse. This bioinspired engineering study has illustrated the potential that a vasculature concept has to offer in terms of providing a self-healing function with minimum mass penalty, without initiating premature failure within a composite structure. PMID:19955122

  3. Mechanically Robust 3D Nanostructure Chitosan-Based Hydrogels with Autonomic Self-Healing Properties.

    Science.gov (United States)

    Karimi, Ali Reza; Khodadadi, Azam

    2016-10-12

    Fabrication of hydrogels based on chitosan (CS) with superb self-healing behavior and high mechanical and electrical properties has become a challenging and fascinating topic. Most of the conventional hydrogels lack these properties at the same time. Our objectives in this research were to synthesize, characterize, and evaluate the general properties of chitosan covalently cross-linked with zinc phthalocyanine tetra-aldehyde (ZnPcTa) framework. Our hope was to access an unprecedented self-healable three-dimensional (3D) nanostructure that would harvest the superior mechanical and electrical properties associated with chitosan. The properties of cross-linker such as the structure, steric effect, and rigidity of the molecule played important roles in determining the microstructure and properties of the resulting hydrogels. The tetra-functionalized phthalocyanines favor a dynamic Schiff-base linkage with chitosan to form a 3D porous nanostructure. Based on this strategy, the self-healing ability, as demonstrated by rheological recovery and macroscopic and microscopic observations, is introduced through dynamic covalent Schiff-base linkage between NH 2 groups in CS and benzaldehyde groups at cross-linker ends. The hydrogel was characterized using FT-IR, NMR, UV/vis, and rheological measurements. In addition, cryogenic scanning electron microscopy (cryo-SEM) was employed as a technique to visualize the internal morphology of the hydrogels. Study of the surface morphology of the hydrogel showed a 3D porous nanostructure with uniform morphology. Furthermore, incorporating the conductive nanofillers, such as carbon nanotubes (CNTs), into the structure can modulate the mechanical and electrical properties of the obtained hydrogels. Interestingly, these hydrogel nanocomposites proved to have very good film-forming properties, high modulus and strength, acceptable electrical conductivity, and excellent self-healing properties at neutral pH. Such properties can be finely tuned

  4. Epithelial self-healing is recapitulated by a 3D biomimetic E-cadherin junction.

    Science.gov (United States)

    Cohen, Daniel J; Gloerich, Martijn; Nelson, W James

    2016-12-20

    Epithelial monolayers undergo self-healing when wounded. During healing, cells collectively migrate into the wound site, and the converging tissue fronts collide and form a stable interface. To heal, migrating tissues must form cell-cell adhesions and reorganize from the front-rear polarity characteristic of cell migration to the apical-basal polarity of an epithelium. However, identifying the "stop signal" that induces colliding tissues to cease migrating and heal remains an open question. Epithelial cells form integrin-based adhesions to the basal extracellular matrix (ECM) and E-cadherin-mediated cell-cell adhesions on the orthogonal, lateral surfaces between cells. Current biological tools have been unable to probe this multicellular 3D interface to determine the stop signal. We addressed this problem by developing a unique biointerface that mimicked the 3D organization of epithelial cell adhesions. This "minimal tissue mimic" (MTM) comprised a basal ECM substrate and a vertical surface coated with purified extracellular domain of E-cadherin, and was designed for collision with the healing edge of an epithelial monolayer. Three-dimensional imaging showed that adhesions formed between cells, and the E-cadherin-coated MTM resembled the morphology and dynamics of native epithelial cell-cell junctions and induced the same polarity transition that occurs during epithelial self-healing. These results indicate that E-cadherin presented in the proper 3D context constitutes a minimum essential stop signal to induce self-healing. That the Ecad:Fc MTM stably integrated into an epithelial tissue and reduced migration at the interface suggests that this biointerface is a complimentary approach to existing tissue-material interfaces.

  5. System Risk Balancing Profiles: Software Component

    Science.gov (United States)

    Kelly, John C.; Sigal, Burton C.; Gindorf, Tom

    2000-01-01

    The Software QA / V&V guide will be reviewed and updated based on feedback from NASA organizations and others with a vested interest in this area. Hardware, EEE Parts, Reliability, and Systems Safety are a sample of the future guides that will be developed. Cost Estimates, Lessons Learned, Probability of Failure and PACTS (Prevention, Avoidance, Control or Test) are needed to provide a more complete risk management strategy. This approach to risk management is designed to help balance the resources and program content for risk reduction for NASA's changing environment.

  6. Automated remedial assessment methodology software system

    International Nuclear Information System (INIS)

    Whiting, M.; Wilkins, M.; Stiles, D.

    1994-11-01

    The Automated Remedial Analysis Methodology (ARAM) software system has been developed by the Pacific Northwest Laboratory to assist the U.S. Department of Energy (DOE) in evaluating cleanup options for over 10,000 contaminated sites across the DOE complex. The automated methodology comprises modules for decision logic diagrams, technology applicability and effectiveness rules, mass balance equations, cost and labor estimating factors and equations, and contaminant stream routing. ARAM is used to select technologies for meeting cleanup targets; determine the effectiveness of the technologies in destroying, removing, or immobilizing contaminants; decide the nature and amount of secondary waste requiring further treatment; and estimate the cost and labor involved when applying technologies

  7. CRISP90 - SOFTWARE DESIGN ANALYZER SYSTEM

    Science.gov (United States)

    Tausworthe, R. C.

    1994-01-01

    The CRISP90 Software Design Analyzer System, an update of CRISP-80, is a set of programs forming a software design and documentation tool which supports top-down, hierarchic, modular, structured design and programming methodologies. The quality of a computer program can often be significantly influenced by the design medium in which the program is developed. The medium must foster the expression of the programmer's ideas easily and quickly, and it must permit flexible and facile alterations, additions, and deletions to these ideas as the design evolves. The CRISP90 software design analyzer system was developed to provide the PDL (Programmer Design Language) programmer with such a design medium. A program design using CRISP90 consists of short, English-like textual descriptions of data, interfaces, and procedures that are imbedded in a simple, structured, modular syntax. The display is formatted into two-dimensional, flowchart-like segments for a graphic presentation of the design. Together with a good interactive full-screen editor or word processor, the CRISP90 design analyzer becomes a powerful tool for the programmer. In addition to being a text formatter, the CRISP90 system prepares material that would be tedious and error prone to extract manually, such as a table of contents, module directory, structure (tier) chart, cross-references, and a statistics report on the characteristics of the design. Referenced modules are marked by schematic logic symbols to show conditional, iterative, and/or concurrent invocation in the program. A keyword usage profile can be generated automatically and glossary definitions inserted into the output documentation. Another feature is the capability to detect changes that were made between versions. Thus, "change-bars" can be placed in the output document along with a list of changed pages and a version history report. Also, items may be marked as "to be determined" and each will appear on a special table until the item is

  8. Nature's Mechanisms for Tough, Self-healing Polymers and Polymer Adhesives

    Science.gov (United States)

    Hansma, Paul

    2007-03-01

    Spider silk^2 and the natural polymer adhesives in abalone shells^3 and bone^4,5 can give us insights into nature's mechanisms for tough, self-healing polymers and polymer adhesives. The natural polymer adhesives in biomaterials have been optimized by evolution. An optimized polymer adhesive has five characteristics. 1) It holds together the strong elements of the composite. 2) It yields just before the strong elements would otherwise break. 3) It dissipates large amounts of energy as it yields. 4) It self heals after it yields. 5) It takes just a few percent by weight. Both natural polymer adhesives and silk rely on sacrificial bonds and hidden length for toughness and self-healing.^6 A relatively large energy, of order 100eV, is required to stretch a polymer molecule after a weak bond, a sacrificial bond, breaks and liberates hidden length, which was previously hidden, typically in a loop or folded domain, from whatever was stretching the polymer. The bond is called sacrificial if it breaks at forces well below the forces that could otherwise break the polymer backbone, typically greater than 1nN. In many biological cases, the breaking of sacrificial bonds has been found to be reversible, thereby also providing a ``self-healing'' property to the material.^2-4 Individual polymer adhesive molecules based on sacrificial bonds and hidden length can supply forces of order 300pN over distances of 100s of nanometers. Model calculations show that a few percent by weight of adhesives based on these principles could be optimized adhesives for high performance composite materials including nanotube and graphene sheet composites. ^2N. Becker, E. Oroudjev, S. Mutz et al., Nature Materials 2 (4), 278 (2003). ^3B. L. Smith, T. E. Schaffer, M. Viani et al., Nature 399 (6738), 761 (1999). ^4J. B. Thompson, J. H. Kindt, B. Drake et al., Nature 414 (6865), 773 (2001). ^5G. E. Fantner, T. Hassenkam, J. H. Kindt et al., Nature Materials 4, 612 (2005). ^6G. E. Fantner, E. Oroudjev, G

  9. Designing Networks that are Capable of Self-Healing and Adapting

    Science.gov (United States)

    2017-04-01

    from statistical mechanics, combinatorics, boolean networks, and numerical simulations, and inspired by design principles from biological networks, we... principles for self-healing networks, and applications, and construct an all-possible-paths model for network adaptation. 2015-11-16 UNIT CONVERSION...kg m –3 ) pound-force (lbf avoirdupois) 4.448 222 newton (N) Energy/Work/Power electron volt (eV) 1.602 177 × 10 –19 joule (J) erg 1 × 10 –7

  10. Scanning electron microscopy of the collodion membrane from a self-healing collodion baby*

    Science.gov (United States)

    de Almeida Jr., Hiram Larangeira; Isaacsson, Henrique; Guarenti, Isabelle Maffei; Silva, Ricardo Marques e; de Castro, Luis Antônio Suita

    2015-01-01

    Abstract Self-healing collodion baby is a well-established subtype of this condition. We examined a male newborn, who was covered by a collodion membrane. The shed membrane was examined with scanning electron microscopy. The outer surface showed a very compact keratin without the normal elimination of corneocytes. The lateral view of the specimen revealed a very thick, horny layer. The inner surface showed the structure of lower corneocytes with polygonal contour. With higher magnifications villous projections were seen in the cell membrane. PMID:26375232

  11. Self-healing of Fractures in Argillaceous Media from the Geomechanical Point of View

    International Nuclear Information System (INIS)

    Horseman, Steve

    2001-01-01

    Presently, there is no established theory describing fracture self-healing and self-sealing processes in mud-rocks (clays, mud-stones and shales) and no methodology to assess the conditions under which these processes might be important. The author suggests that the modified Cam-Clay approach provides a useful conceptual and theoretical framework for the analysis of the largely hydro-mechanical process of self-sealing. Three basic hypotheses are proposed and applied to the problem of fracture self-sealing in the repository EDZ and to the more general question of fault sealing. (author)

  12. Autonomous distributed self-organizing and self-healing hardware architecture - The eDNA concept

    DEFF Research Database (Denmark)

    Boesen, Michael Reibel; Madsen, Jan; Keymeulen, Didier

    2011-01-01

    This paper presents the current state of the autonomous distributed self-organizing and self-healing electronic DNA (eDNA) hardware architecture (patent pending). In its current prototype state, the eDNA architecture is capable of responding to multiple injected faults by autonomously reconfiguring...... itself to accommodate the fault and keep the application running. This paper will also disclose advanced features currently available in the simulation model only. These features are future work and will soon be implemented in hardware. Finally we will describe step-by-step how an application...

  13. Self-healing polymeric composite material design, failure analysis and future outlook: A review

    CSIR Research Space (South Africa)

    Mphahlele, Keletso

    2017-10-01

    Full Text Available , as well as the intrinsic organization of polymer chains [84,93–96]. Polymers 2017, 9, 535 10 of 22 Perhaps the two most studied interactions so far are those found in ionomers for ballistic [82,97] and coating applications and hydrogen bonding represented... by the well-defined ureidopyrimidinone constituent and the use of randomly branched oligomers equipped with self-complementary and complementary hydrogen bonding groups [82]. The self-healing method of ionomers originates from the intrinsic chemical structure...

  14. An adaptive self-healing ionic liquid nanocomposite membrane for olefin-paraffin separations.

    Science.gov (United States)

    Pitsch, Fee; Krull, Florian F; Agel, Friederike; Schulz, Peter; Wasserscheid, Peter; Melin, Thomas; Wessling, Matthias

    2012-08-16

    An adaptive self-healing ionic liquid nanocomposite membrane comprising a multi-layer support structure hosting the ionic salt [Ag](+) [Tf(2) N](-) is used for the separation of the olefin propylene and the paraffin propane. The ionic salt renders liquid like upon complexation with propylene, resulting in facilitated transport of propylene over propane at benchmark-setting selectivity and permeance levels. The contacting with acetylene causes the ionic salt to liquefy without showing evidence of forming explosive silver acetylide. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Software qualification for digital safety system in KNICS project

    International Nuclear Information System (INIS)

    Kwon, Kee-Choon; Lee, Dong-Young; Choi, Jong-Gyun

    2012-01-01

    In order to achieve technical self-reliance in the area of nuclear instrumentation and control, the Korea Nuclear Instrumentation and Control System (KNICS) project had been running for seven years from 2001. The safety-grade Programmable Logic Controller (PLC) and the digital safety system were developed by KNICS project. All the software of the PLC and digital safety system were developed and verified following the software development life cycle Verification and Validation (V and V) procedure. The main activities of the V and V process are preparation of software planning documentations, verification of the Software Requirement Specification (SRS), Software Design Specification (SDS) and codes, and a testing of the software components, the integrated software, and the integrated system. In addition, a software safety analysis and a software configuration management are included in the activities. For the software safety analysis at the SRS and SDS phases, the software Hazard Operability (HAZOP) was performed and then the software fault tree analysis was applied. The software fault tree analysis was applied to a part of software module with some critical defects identified by the software HAZOP in SDS phase. The software configuration management was performed using the in-house tool developed in the KNICS project. (author)

  16. Software Configuration Management Plan for the Sodium Removal System

    International Nuclear Information System (INIS)

    HILL, L.F.

    2000-01-01

    This document establishers the Software Configuration Management Plan (SCMP) for the software associated with the control system of the Sodium Removal System (SRS) located in the Interim Examination and Maintenance (IEM Cell) Facility of the FFTF Flux Test

  17. Control system software, simulation, and robotic applications

    Science.gov (United States)

    Frisch, Harold P.

    1991-01-01

    All essential existing capabilities needed to create a man-machine interaction dynamics and performance (MMIDAP) capability are reviewed. The multibody system dynamics software program Order N DISCOS will be used for machine and musculo-skeletal dynamics modeling. The program JACK will be used for estimating and animating whole body human response to given loading situations and motion constraints. The basic elements of performance (BEP) task decomposition methodologies associated with the Human Performance Institute database will be used for performance assessment. Techniques for resolving the statically indeterminant muscular load sharing problem will be used for a detailed understanding of potential musculotendon or ligamentous fatigue, pain, discomfort, and trauma. The envisioned capacity is to be used for mechanical system design, human performance assessment, extrapolation of man/machine interaction test data, biomedical engineering, and soft prototyping within a concurrent engineering (CE) system.

  18. Assessing waste management systems using reginalt software

    International Nuclear Information System (INIS)

    Meshkov, N.K.; Camasta, S.F.; Gilbert, T.L.

    1988-03-01

    A method for assessing management systems for low-level radioactive waste is being developed for US Department of Energy. The method is based on benefit-cost-risk analysis. Waste management is broken down into its component steps, which are generation, treatment, packaging, storage, transportation, and disposal. Several different alternatives available for each waste management step are described. A particular waste management system consists of a feasible combination of alternatives for each step. Selecting an optimal waste management system would generally proceed as follows: (1) qualitative considerations are used to narrow down the choice of waste management system alternatives to a manageable number; (2) the costs and risks for each of these system alternatives are evaluated; (3) the number of alternatives is further reduced by eliminating alternatives with similar risks but higher costs, or those with similar costs but higher risks; (4) a trade-off factor between cost and risk is chosen and used to compute the objective function (sum of the cost and risk); and (5) the selection of the optimal waste management system among the remaining alternatives is made by choosing the alternative with the smallest value for the objective function. The authors propose that the REGINALT software system, developed by EG and G Idaho, Inc., as an acid for managers of low-level commerical waste, be augmented for application to the managment of DOE-generated waste. Specific recommendations for modification of the REGINALT system are made. 51 refs., 3 figs., 2 tabs

  19. Software tools for microprocessor based systems

    International Nuclear Information System (INIS)

    Halatsis, C.

    1981-01-01

    After a short review of the hardware and/or software tools for the development of single-chip, fixed instruction set microprocessor-based sytems we focus on the software tools for designing systems based on microprogrammed bit-sliced microprocessors. Emphasis is placed on meta-microassemblers and simulation facilties at the register-transfer-level and architecture level. We review available meta-microassemblers giving their most important features, advantages and disadvantages. We also make extentions to higher-level microprogramming languages and associated systems specifically developed for bit-slices. In the area of simulation facilities we first discuss the simulation objectives and the criteria for chosing the right simulation language. We consertrate to simulation facilities already used in bit-slices projects and discuss the gained experience. We conclude by describing the way the Signetics meta-microassembler and the ISPS simulation tool have been employed in the design of a fast microprogrammed machine, called MICE, made out of ECL bit-slices. (orig.)

  20. 14 CFR 415.123 - Computing systems and software.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Computing systems and software. 415.123... Launch Vehicle From a Non-Federal Launch Site § 415.123 Computing systems and software. (a) An applicant's safety review document must describe all computing systems and software that perform a safety...

  1. AIRMaster: Compressed air system audit software

    International Nuclear Information System (INIS)

    Wheeler, G.M.; Bessey, E.G.; McGill, R.D.; Vischer, K.

    1997-01-01

    The project goal was to develop a software tool, AIRMaster, and a methodology for performing compressed air system audits. AIRMaster and supporting manuals are designed for general auditors or plant personnel to evaluate compressed air system operation with simple instrumentation during a short-term audit. AIRMaster provides a systematic approach to compressed air system audits, analyzing collected data, and reporting results. AIRMaster focuses on inexpensive Operation and Maintenance (O and M) measures, such as fixing air leaks and improving controls that can significantly improve performance and reliability of the compressed air system, without significant risk to production. An experienced auditor can perform an audit, analyze collected data, and produce results in 2--3 days. AIRMaster reduces the cost of an audit, thus freeing funds to implement recommendations. The AIRMaster package includes an Audit Manual, Software and User's manual, Analysis Methodology Manual, and a Case Studies summary report. It also includes a Self-Guided Tour booklet to help users quickly screen a plant for efficiency improvement potentials, and an Industrial Compressed Air Systems Energy Efficiency Guidebook. AIRMaster proved to be a fast and effective audit tool. In sever audits AIRMaster identified energy savings of 4,056,000 kWh, or 49.2% of annual compressor energy use, for a cost savings of $152,000. Total implementation costs were $94,700 for a project payback period of 0.6 years. Available airflow increased between 11% and 51% of plant compressor capacity, leading to potential capital benefits from 40% to 230% of first year energy savings

  2. Studying the Combination Effect of Additives and Micro Steel Fibers on Cracks of Self-Healing Concrete

    Directory of Open Access Journals (Sweden)

    Muhannad Hussien Muhsin

    2017-01-01

    Full Text Available In this study, the effect of the combination of micro steel fibers and additives (calcium hydroxide and sodium carbonate on the size of cracks formation and healing them were investigated. This study aims to apply the use of self-healing phenomenon to repair cracks and to enhance the service life of the concrete structures. Micro steel fibers straight type were used in this research with 0.2% and 0.4% by volume of concrete. A weight of 20 and 30 kg/m3 of Ca(OH2 and 2 and 3 kg/m3 of Na2CO3 were used as a partial cement replacement. The results confirm that the concrete cracks were significantly self-healed up to 30 days re-curing. Cracks width up to 0.2 mm were completely self-healed after re-curing for 90 days by using the combination of micro steel fiber of 0.4% by volume of concrete and 25 kg/m3 of Ca(OH2 and 2.5 kg/m3 of Na2CO3 as a partial replacement of cement. Products of Self-healing are observed by Scanning Electron Microscopy (SEM with Energy Dispersive X-Ray Analysis (EDX. It was found that self-healing occurred mainly due to precipitation of calcium carbonate.

  3. The Systems Biology Research Tool: evolvable open-source software

    OpenAIRE

    Wright, J; Wagner, A

    2008-01-01

    Abstract Background Research in the field of systems biology requires software for a variety of purposes. Software must be used to store, retrieve, analyze, and sometimes even to collect the data obtained from system-level (often high-throughput) experiments. Software must also be used to implement mathematical models and algorithms required for simulation and theoretical predictions on the system-level. Results We introduce a free, easy-to-use, open-source, integrated software platform calle...

  4. Synthesis of alumina ceramic encapsulation for self-healing materials on thermal barrier coating

    Science.gov (United States)

    Golim, O. P.; Prastomo, N.; Izzudin, H.; Hastuty, S.; Sundawa, R.; Sugiarti, E.; Thosin, K. A. Z.

    2018-03-01

    Durability of Thermal Barrier Coating or TBC can be optimized by inducing Self-Healing capabilities with intermetallic materials MoSi2. Nevertheless, high temperature operation causes the self-healing materials to become oxidized and lose its healing capabilities. Therefore, a method to introduce ceramic encapsulation for MoSi2 is needed to protect it from early oxidation. The encapsulation process is synthesized through a simple precipitation method with colloidal aluminum hydroxide as precursor and variations on calcination process. Semi-quantitative analysis on the synthesized sample is done by using X-ray diffraction (XRD) method. Meanwhile, qualitative analysis on the morphology of the encapsulation was carried out by using Scanning Electron Microscope (SEM) and Field Emission Scanning Electron Microscope (FESEM) equipped with dual Focus Ion Beam (FIB). The result of the experiment shows that calcination process significantly affects the final characteristic of encapsulation. The optimum encapsulation process was synthesized by colloidal aluminum hydroxide as a precursor, with a double step calcination process in low pressure until 900 °C.

  5. An Innovative Approach to Control Steel Reinforcement Corrosion by Self-Healing

    Directory of Open Access Journals (Sweden)

    Dessi A. Koleva

    2018-02-01

    Full Text Available The corrosion of reinforced steel, and subsequent reinforced concrete degradation, is a major concern for infrastructure durability. New materials with specific, tailor-made properties or the establishment of optimum construction regimes are among the many approaches to improving civil structure performance. Ideally, novel materials would carry self-repairing or self-healing capacities, triggered in the event of detrimental influence and/or damage. Controlling or altering a material’s behavior at the nano-level would result in traditional materials with radically enhanced properties. Nevertheless, nanotechnology applications are still rare in construction, and would break new ground in engineering practice. An approach to controlling the corrosion-related degradation of reinforced concrete was designed as a synergetic action of electrochemistry, cement chemistry and nanotechnology. This contribution presents the concept of the approach, namely to simultaneously achieve steel corrosion resistance and improved bulk matrix properties. The technical background and challenges for the application of polymeric nanomaterials in the field are briefly outlined in view of this concept, which has the added value of self-healing. The credibility of the approach is discussed with reference to previously reported outcomes, and is illustrated via the results of the steel electrochemical responses and microscopic evaluations of the discussed materials.

  6. Self-healing in single and multiple fiber(s reinforced polymer composites

    Directory of Open Access Journals (Sweden)

    Woldesenbet E.

    2010-06-01

    Full Text Available You Polymer composites have been attractive medium to introduce the autonomic healing concept into modern day engineering materials. To date, there has been significant research in self-healing polymeric materials including several studies specifically in fiber reinforced polymers. Even though several methods have been suggested in autonomic healing materials, the concept of repair by bleeding of enclosed functional agents has garnered wide attention by the scientific community. A self-healing fiber reinforced polymer composite has been developed. Tensile tests are carried out on specimens that are fabricated by using the following components: hollow and solid glass fibers, healing agent, catalysts, multi-walled carbon nanotubes, and a polymer resin matrix. The test results have demonstrated that single fiber polymer composites and multiple fiber reinforced polymer matrix composites with healing agents and catalysts have provided 90.7% and 76.55% restoration of the original tensile strength, respectively. Incorporation of functionalized multi-walled carbon nanotubes in the healing medium of the single fiber polymer composite has provided additional efficiency. Healing is found to be localized, allowing multiple healing in the presence of several cracks.

  7. An Innovative Approach to Control Steel Reinforcement Corrosion by Self-Healing

    Science.gov (United States)

    2018-01-01

    The corrosion of reinforced steel, and subsequent reinforced concrete degradation, is a major concern for infrastructure durability. New materials with specific, tailor-made properties or the establishment of optimum construction regimes are among the many approaches to improving civil structure performance. Ideally, novel materials would carry self-repairing or self-healing capacities, triggered in the event of detrimental influence and/or damage. Controlling or altering a material’s behavior at the nano-level would result in traditional materials with radically enhanced properties. Nevertheless, nanotechnology applications are still rare in construction, and would break new ground in engineering practice. An approach to controlling the corrosion-related degradation of reinforced concrete was designed as a synergetic action of electrochemistry, cement chemistry and nanotechnology. This contribution presents the concept of the approach, namely to simultaneously achieve steel corrosion resistance and improved bulk matrix properties. The technical background and challenges for the application of polymeric nanomaterials in the field are briefly outlined in view of this concept, which has the added value of self-healing. The credibility of the approach is discussed with reference to previously reported outcomes, and is illustrated via the results of the steel electrochemical responses and microscopic evaluations of the discussed materials. PMID:29461495

  8. Damage detection monitoring applications in self-healing concrete structures using embedded piezoelectric transducers and recovery

    International Nuclear Information System (INIS)

    Karaiskos, G; Tsangouri, E; Aggelis, D G; Van Hemelrijck, D; Deraemaeker, A

    2015-01-01

    The ageing, operational and ambient loadings have a great impact in the operational and maintenance cost of concrete structures. Their service life prolongation is of utmost importance and this can be efficiently achieved by using reliable and low-cost monitoring and self-healing techniques. In the present study, the ultrasonic pulse velocity (UPV) method using embedded small-size and low-cost piezoelectric PZT (lead zirconate titanate) ceramic transducers in concrete with self-healing properties is implemented for monitoring not only the setting and hardening phases of concrete since casting time, but also for the detection of damage initiation, propagation and recovery of integrity after healing. A couple of small-scale notched unreinforced concrete beams are subjected to mode-I fracture through three-point bending tests. After a 24-hour healing agent curing period, the beams are reloaded using the same loading scenario. The results demonstrate the excellent performance of the proposed monitoring technique during the hydration, damage generation and recovery periods. (paper)

  9. Polymer-Cement Composites with Self-Healing Ability for Geothermal and Fossil Energy Applications

    Energy Technology Data Exchange (ETDEWEB)

    Childers, M. Ian; Nguyen, Manh-Thuong; Rod, Kenton A.; Koech, Phillip K.; Um, Wooyong; Chun, Jaehun; Glezakou, Vassiliki-Alexandra; Linn, Diana; Roosendaal, Timothy J.; Wietsma, Thomas W.; Huerta, Nicolas John; Kutchko, Barbara G.; Fernandez, Carlos A.

    2017-05-18

    Sealing of wellbores in geothermal and tight oil/gas reservoirs by filling the annulus with cement is a well-established practice. Failure of the cement as a result of physical and/or chemical stress is a common problem with serious environmental and financial consequences. Numerous alternative cement blends have been proposed for the oil and gas industry. Most of these possess poor mechanical properties, or are not designed to work in high temperature environments. This work reports on a novel polymer-cement composite with remarkable self-healing ability that maintains the required properties of typical wellbore cements and may be stable at most geothermal temperatures. We combine for the first time experimental analysis of physical and chemical properties with density functional theory simulations to evaluate cement performance. The thermal stability and mechanical strength are attributed to the formation of a number of chemical interactions between the polymer and cement matrix including covalent bonds, hydrogen bonding, and van der Waals interactions. Self-healing was demonstrated by sealing fractures with 0.3–0.5 mm apertures, 2 orders of magnitude larger than typical wellbore fractures. This polymer-cement composite represents a major advance in wellbore cementing that could improve the environmental safety and economics of enhanced geothermal energy and tight oil/gas production.

  10. Self-healing Anticorrosion Coatings for Gas Pipelines and Storage Tanks

    Energy Technology Data Exchange (ETDEWEB)

    Luckachan, G. E.; Mittal, V. [The Petroleum Institute, Abudhabi (United Arab Emirates)

    2016-10-15

    In the present study, chitosan based self-healing anticorrosion coatings were prepared by layer by layer (lbl) addition of chitosan (Ch) and polyvinyl butyral (PVB) on mild carbon steel substrate. Chitosan coatings exhibited enhanced coating stability and corrosion resistance in aggressive environments by the application of a PVB top layer. Chitosan layer in the lbl coatings have been modified by using glutaraldehyde (Glu) and silica (SiO{sub 2}). Performance of different coatings was tested using electrochemical impedance spectroscopy and immersion test. The best anticorrosion performance was observed in case of 10 % Ch{sub S}iO{sub 2P}VB coatings, which withstand immersion test over 25 days in 0.5 M salt solution without visible corrosion. 10 % Ch{sub S}iO{sub 2} coatings without the PVB top layer didn't last more than 3days. Application of PVB top layer sealed the defects in the chitosan pre-layer and improved its hydrophobic nature as well. Raman spectra and SEM of steel surfaces after corrosion study and removal of PVB{sub C}h/Glu{sub P}VB coatings showed a passive layer of iron oxide, attributing to the self-healing nature of these coatings. Conducting particle like graphene reinforcement of chitosan in the lbl coatings enhanced corrosion resistance of chitosan coatings.

  11. Bacillus sphaericus LMG 22257 is physiologically suitable for self-healing concrete.

    Science.gov (United States)

    Wang, Jianyun; Jonkers, Henk M; Boon, Nico; De Belie, Nele

    2017-06-01

    The suitability of using a spore-forming ureolytic strain, Bacillus sphaericus, was evaluated for self-healing of concrete cracks. The main focus was on alkaline tolerance, calcium tolerance, oxygen dependence, and low-temperature adaptability. Experimental results show that B. sphaericus had a good tolerance. It can grow and germinate in a broad range of alkaline pH. The optimal pH range is 7 ∼ 9. High alkaline conditions (pH 10 ∼ 11) slow down but not stop the growth and germination. Oxygen was strictly needed during bacterial growth and germination, but not an essential factor during bacterial urea decomposition. B. sphaericus also had a good Ca tolerance, especially at a high bacterial concentration of 10 8  cells/mL; no significant influence was observed on bacterial ureolytic activity of the presence of 0.9M Ca 2+ . Furthermore, at a low temperature (10 °C), bacterial spores germinated and revived ureolytic activity with some retardation. However, this retardation can be counteracted by using a higher bacterial concentration and by supplementing yeast extract. It can be concluded that B. sphaericus is a suitable bacterium for application in bacteria-based self-healing concrete.

  12. On the development of polypyrrole coatings with self-healing properties for iron corrosion protection

    International Nuclear Information System (INIS)

    Paliwoda-Porebska, G.; Stratmann, M.; Rohwerder, M.; Potje-Kamloth, K.; Lu, Y.; Pich, A.Z.; Adler, H.-J.

    2005-01-01

    This paper presents studies on the efficacy and on the limits of polypyrrole (Ppy) doped with either MoO 4 2- or [PMo 12 O 40 ] 3- as self-healing corrosion protecting coatings. The kinetics of the cathodic delamination were studied by means of the Scanning Kelvin Probe (SKP). This method, in combination with cyclic voltammetry, UV-visible spectroscopy (UV-vis) and X-ray photoelectron spectroscopy (XPS), shows a potential driven anion release from the Ppy coating that results in an inhibition of the corrosion process taking place in the defect. Thus, an intelligent release of inhibitor occurs only when the potential at the interface decreases. Inhibitor anions are released only due to an active defect. However, the release mechanism can be easily negatively affected by the presence of small cations and/or by too high pH values at the buried interface. Hence, such a self-healing coating has to be carefully designed in order to ensure an effective performance

  13. Injectable self-healing carboxymethyl chitosan-zinc supramolecular hydrogels and their antibacterial activity.

    Science.gov (United States)

    Wahid, Fazli; Zhou, Ya-Ning; Wang, Hai-Song; Wan, Tong; Zhong, Cheng; Chu, Li-Qiang

    2018-04-07

    Injectable and self-healing hydrogels have found numerous applications in drug delivery, tissue engineering and 3D cell culture. Herein, we report an injectable self-healing carboxymethyl chitosan (CMCh) supramolecular hydrogels cross-linked by zinc ions (Zn 2+ ). Supramolecular hydrogels were obtained by simple addition of metal ions solution to CMCh solution at an appropriate pH value. The mechanical properties of these hydrogels were adjustable by the concentration of Zn 2+ . For example, the hydrogel with the highest concentration of Zn 2+ (CMCh-Zn4) showed strongest mechanical properties (storage modulus~11,000Pa) while hydrogel with the lowest concentration of Zn 2+ (CMCh-Zn1) showed weakest mechanical properties (storage modulus~220Pa). As observed visually and confirmed rheologically, the CMCh-Zn1 hydrogel with the lowest Zn 2+ concentration showed thixotropic property. CMCh-Zn1 hydrogel also presented injectable property. Moreover, the antibacterial properties of the prepared supramolecular hydrogels were studied against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) by agar well diffusion method. The results revealed Zn 2+ dependent antibacterial properties against both kinds of strains. The inhibition zones were ranging from ~11-24mm and ~10-22mm against S. aureus and E. coli, respectively. We believe that the prepared supramolecular hydrogels could be used as a potential candidate in biomedical fields. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Abalone water-soluble matrix for self-healing biomineralization of tooth defects.

    Science.gov (United States)

    Wen, Zhenliang; Chen, Jingdi; Wang, Hailiang; Zhong, Shengnan; Hu, Yimin; Wang, Zhili; Zhang, Qiqing

    2016-10-01

    Enamel cannot heal by itself if damaged. Hydroxyapatite (HAP) is main component of human enamel. Formation of enamel-like materials for healing enamel defects remains a challenge. In this paper, we successfully isolated the abalone water-soluble matrix (AWSM) with 1.53wt% the abalone water-soluble protein (AWSPro) and 2.04wt% the abalone water-soluble polysaccharide (AWSPs) from abandoned abalone shell, and self-healing biomineralization of tooth defects was successfully achieved in vitro. Based on X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), hot field emission scanning electron microscopy (HFESEM) and energy dispersive spectrometer (EDS) analysis, the results showed that the AWSM can efficiently induce remineralization of HAP. The enamel-like HAP was successfully achieved onto etched enamel's surface due to the presence of the AWSM. Moreover, the remineralized effect of eroded enamel was growing with the increase of the AWSM. This study provides a solution to the resource waste and environmental pollution caused by abandoned abalone shell, and we provides a new method for self-healing remineralization of enamel defects by AWSM and develops a novel dental material for potential clinical dentistry application. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. System software of the CERN proton synchrotron control system

    International Nuclear Information System (INIS)

    Carpenter, B.E.; Cailliau, R.; Cuisinier, G.; Remmer, W.

    1984-01-01

    The PS complex consists of 10 different interconnected accelerators or storage rings, mainly controlled by the same distributed system of NORD-10 and ND-100 minicomputers. After a brief outline of the hardware, this report gives a detailed description of the system software, which is based on the SINTRAN III operating system. It describes the general layout of the software, the network, CAMAC access, programming languages, program development, and microprocessor support. It concludes with reviews of performance, documentation, organization and methods, and future prospects. (orig.)

  16. Overview of recent work on self-healing in cementitious materials

    Directory of Open Access Journals (Sweden)

    Lv, Z.

    2014-12-01

    Full Text Available Cracks, especially microcracks, in concrete are of paramount importance to the durability and the service life of cementitious composite. However, the self-healing technology, including autogenous healing and autonomous healing, is expected to be one of effective tools to overcome this boring problem. In this paper, we focus on the autogenous healing of concrete material and a few of recent works of autonomous healing are also mentioned. The durability and the mechanical properties improved by the self-healing phenomenon are reviewed from experimental investigation and practical experience. Several aspects of researches, such as autogenous healing capability of an innovative concrete incorporated geo-materials, self-healing of engineered cementitious composite and fire-damaged concrete, effect of mineral and admixtures on mechanism and efficiency of self-healing concrete are summarized to evaluate the presented progresses in the past several years and to outline the perspective for the further developments. Moreover, a special emphasis is given on the analytical models and computer simulation method of the researches of self-healing in cementitious materials.Las fisuras, y sobre todo las microfisuras, tienen una gran repercusión en la durabilidad y en la vida útil de los materiales cementantes. Ante este problema, la tecnología de la autorreparación, tanto autógena como autónoma, se presenta como una solución eficaz. El artículo se centra en la reparación autógena del hormigón, así como en algunos trabajos recientes sobre la reparación autónoma. Se describen las mejoras de las propiedades de durabilidad y de resistencia que proporciona la técnica del hormigón autorreparable, tanto desde el punto de vista de la investigación experimental como del de la experiencia práctica. A fin de evaluar los avances logrados en los últimos años y de trazar las grandes líneas de desarrollo futuro, se resumen varios de los aspectos

  17. Physics detector simulation facility system software description

    International Nuclear Information System (INIS)

    Allen, J.; Chang, C.; Estep, P.; Huang, J.; Liu, J.; Marquez, M.; Mestad, S.; Pan, J.; Traversat, B.

    1991-12-01

    Large and costly detectors will be constructed during the next few years to study the interactions produced by the SSC. Efficient, cost-effective designs for these detectors will require careful thought and planning. Because it is not possible to test fully a proposed design in a scaled-down version, the adequacy of a proposed design will be determined by a detailed computer model of the detectors. Physics and detector simulations will be performed on the computer model using high-powered computing system at the Physics Detector Simulation Facility (PDSF). The SSCL has particular computing requirements for high-energy physics (HEP) Monte Carlo calculations for the simulation of SSCL physics and detectors. The numerical calculations to be performed in each simulation are lengthy and detailed; they could require many more months per run on a VAX 11/780 computer and may produce several gigabytes of data per run. Consequently, a distributed computing environment of several networked high-speed computing engines is envisioned to meet these needs. These networked computers will form the basis of a centralized facility for SSCL physics and detector simulation work. Our computer planning groups have determined that the most efficient, cost-effective way to provide these high-performance computing resources at this time is with RISC-based UNIX workstations. The modeling and simulation application software that will run on the computing system is usually written by physicists in FORTRAN language and may need thousands of hours of supercomputing time. The system software is the ''glue'' which integrates the distributed workstations and allows them to be managed as a single entity. This report will address the computing strategy for the SSC

  18. Characterization and kinetic study of Diels-Alder reaction: Detailed study on N-phenylmaleimide and furan based benzoxazine with potential self-healing application

    Directory of Open Access Journals (Sweden)

    Z. Stirn

    2016-07-01

    Full Text Available The Diels-Alder reaction between N-phenylmaleimide and benzoxazine bearing furan group was investigated for the purpose of successful appliance of self-healing in benzoxazine polymer networks. The reaction as a function of temperature/time was performed in molten state and in a solution, where also the kinetic study was performed. The Diels-Alder reaction leads to a mixture of two diastereomers: endo presented at lower cyclo-reversion temperature and exo at higher. Therefore, the conversion rates and exo/endo ratio were studied in detail for both systems. For instance, in molten state the Diels-Alder reaction was triggered by the temperature of the melting point at 60 °C with exo/endo ratio preferable to the endo adduct. The study of the kinetics in a solution revealed that the Diels-Alder reaction followed typical bimolecular reversible second-order reaction. The activation energies were close to the previous literature data; 48.4 and 51.9 kJ·mol–1 for Diels-Alder reaction, and 91.0 and 102.3 kJ·mol–1 for retro-Diels-Alder reaction, in acetonitrile and chloroform, respectively. The reaction equilibrium in a solution is much more affected by the retro-Diels-Alder reaction than in a molten state. This study shows detailed investigation of DA reaction and provides beneficial knowledge for further use in self-healing polymer networks.

  19. Evaluation of self-healing ability of Ce–V conversion coating on AZ31 magnesium alloy

    Directory of Open Access Journals (Sweden)

    Xiao Jiang

    2016-09-01

    Full Text Available This study investigated the influence of cerium nitrate in vanadate solutions on the properties of Ce–V conversion coatings on AZ31 magnesium alloys, and evaluated the self-healing behavior of the Ce–V conversion coating for AZ31 magnesium alloy. The results showed that the additions of cerium nitrate prevented pentavalent vanadium from reducing to tetravalent vanadium in the coatings during conversion reaction process. Adding appropriate cerium nitrate to vanadate solution led to a thicker coating with a more compact CeVO4 layer. The corrosion behavior of the Ce–V conversion coating was investigated by the electrochemical tests and the scratch immersion test in 3.5 wt.% NaCl solution. The self-healing ability of the coating was confirmed from all tests. The surface analysis revealed that the self-healing effect of the Ce–V conversion coating was only provided by the release and migration of vanadium compounds.

  20. Development of Self-Healing Coatings Based on Linseed Oil as Autonomous Repairing Agent for Corrosion Resistance

    Directory of Open Access Journals (Sweden)

    Karan Thanawala

    2014-11-01

    Full Text Available In recent years corrosion-resistant self-healing coatings have witnessed strong growth and their successful laboratory design and synthesis categorises them in the family of smart/multi-functional materials. Among various approaches for achieving self-healing, microcapsule embedment through the material matrix is the main one for self-healing ability in coatings. The present work focuses on optimizing the process parameters for developing microcapsules by in-situ polymerization of linseed oil as core and urea-formaldehyde as shell material. Characteristics of these microcapsules with respect to change in processing parameters such as stirring rate and reaction time were studied by using optical microscopy (OM, scanning electron microscopy (SEM and Fourier transform infrared spectroscopy (FT-IR. The effectiveness of these microcapsules in coatings was characterized by studying their adhesion, performance, and mechanical properties.

  1. Software on the Peregrine System | High-Performance Computing | NREL

    Science.gov (United States)

    on the Peregrine System Software on the Peregrine System NREL maintains a variety of applications environment modules for use on Peregrine. Applications View list of software applications by name and research area/discipline. Libraries View list of software libraries available for linking and loading

  2. The Utility of Open Source Software in Military Systems

    National Research Council Canada - National Science Library

    Esperon, Agustin I; Munoz, Jose P; Tanneau, Jean M

    2005-01-01

    .... The companies involved were THALES and GMV. The MILOS project aimed to demonstrate benefits of Open Source Software in large software based military systems, by casting off constraints inherent to traditional proprietary COTS and by taking...

  3. Analyzing Software Errors in Safety-Critical Embedded Systems

    Science.gov (United States)

    Lutz, Robyn R.

    1994-01-01

    This paper analyzes the root causes of safty-related software faults identified as potentially hazardous to the system are distributed somewhat differently over the set of possible error causes than non-safety-related software faults.

  4. Using CASE Software to Teach Undergraduates Systems Analysis and Design.

    Science.gov (United States)

    Wilcox, Russell E.

    1988-01-01

    Describes the design and delivery of a college course for information system students utilizing a Computer-Aided Software Engineering program. Discusses class assignments, cooperative learning, student attitudes, and the advantages of using this software in the course. (CW)

  5. A communication-channel-based representation system for software

    NARCIS (Netherlands)

    Demirezen, Zekai; Tanik, Murat M.; Aksit, Mehmet; Skjellum, Anthony

    We observed that before initiating software development the objectives are minimally organized and developers introduce comparatively higher organization throughout the design process. To be able to formally capture this observation, a new communication channel representation system for software is

  6. Engineering Software Suite Validates System Design

    Science.gov (United States)

    2007-01-01

    EDAptive Computing Inc.'s (ECI) EDAstar engineering software tool suite, created to capture and validate system design requirements, was significantly funded by NASA's Ames Research Center through five Small Business Innovation Research (SBIR) contracts. These programs specifically developed Syscape, used to capture executable specifications of multi-disciplinary systems, and VectorGen, used to automatically generate tests to ensure system implementations meet specifications. According to the company, the VectorGen tests considerably reduce the time and effort required to validate implementation of components, thereby ensuring their safe and reliable operation. EDASHIELD, an additional product offering from ECI, can be used to diagnose, predict, and correct errors after a system has been deployed using EDASTAR -created models. Initial commercialization for EDASTAR included application by a large prime contractor in a military setting, and customers include various branches within the U.S. Department of Defense, industry giants like the Lockheed Martin Corporation, Science Applications International Corporation, and Ball Aerospace and Technologies Corporation, as well as NASA's Langley and Glenn Research Centers

  7. Visual software system for memory interleaving simulation

    Directory of Open Access Journals (Sweden)

    Milenković Katarina

    2017-01-01

    Full Text Available This paper describes the visual software system for memory interleaving simulation (VSMIS, implemented for the purpose of the course Computer Architecture and Organization 1, at the School of Electrical Engineering, University of Belgrade. The simulator enables students to expand their knowledge through practical work in the laboratory, as well as through independent work at home. VSMIS gives users the possibility to initialize parts of the system and to control simulation steps. The user has the ability to monitor simulation through graphical representation. It is possible to navigate through the entire hierarchy of the system using simple navigation. During the simulation the user can observe and set the values of the memory location. At any time, the user can reset the simulation of the system and observe it for different memory states; in addition, it is possible to save the current state of the simulation and continue with the execution of the simulation later. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III44009

  8. Command and Control System Software Development

    Science.gov (United States)

    Velasquez, Ricky

    2017-01-01

    Kennedy Space Center has been the heart of human space flight for decades. From the Apollo Program to the Space Shuttle Program, and now to the coming Space Launch System (SLS) and Orion, NASA will be a leader in deep space exploration for mankind. Before any rockets blast off, there is significant work to be done in preparation for launch. People working on all aspects of spaceflight must contribute by developing new technology that has yet to participate in a successful launch, and which can work with technology already proven in flight. These innovations, whether hardware or software, must be tried and true, and includes the projects to which interns contribute to. For this internship, the objective was to create a data recording system for the developers of a LCS section that records certain messages in the traffic of the system. Developers would then be able to use these recordings for analysis later on, either manually or by an automated test. The tool would be of convenience to a developer as it would be used if the system's main data recorder was not available for tests.

  9. Static and fatigue tensile properties of cross-ply laminates containing vascules for self-healing applications

    International Nuclear Information System (INIS)

    Luterbacher, R; Trask, R S; Bond, I P

    2016-01-01

    The effect of including hollow channels (vascules) within cross-ply laminates on static tensile properties and fatigue performance is investigated. No change in mechanical properties or damage formation is observed when a single vascule is included in the 0/90 interface, representing 0.5% of the cross sectional area within the specimen. During tensile loading, matrix cracks develop in the 90° layers leading to a reduction of stiffness and strength (defined as the loss of linearity) and a healing agent is injected through the vascules in order to heal them and mitigate the caused degradation. Two different healing agents, a commercial low viscosity epoxy resin (RT151, Resintech) and a toughened epoxy blend (bespoke, in-house formulation) have been used to successfully recover stiffness under static loading conditions. The RT151 system recovered 75% of the initial failure strength, whereas the toughened epoxy blend achieved a recovery of 67%. Under fatigue conditions, post healing, a rapid decay of stiffness was observed as the healed damage re-opened within the first 2500 cycles. This was caused by the high fatigue loading intensity, which was near the static failure strength of the healing resin. However, the potential for ameliorating (via self-healing or autonomous repair) more diffuse transverse matrix damage via a vascular network has been shown. (paper)

  10. Optimization of process factors for self-healing vanadium-based conversion coating on AZ31 magnesium alloy

    Science.gov (United States)

    Li, Kun; Liu, Junyao; Lei, Ting; Xiao, Tao

    2015-10-01

    A self-healing vanadium-based conversion coating was prepared on AZ31 magnesium alloy. The optimum operating conditions including vanadia solution concentration, pH and treating temperature for obtaining the best corrosion protective vanadia coatings and improved localized corrosion resistance to the magnesium substrate were determined by an orthogonal experiment design. Surface morphology and composition of the resultant conversion coatings were investigated by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The self-healing behavior of the coating was investigated by cross-cut immersion test and electrochemical impedance spectroscopy (EIS) measurements in 3.5% NaCl solution.

  11. RT-Syn: A real-time software system generator

    Science.gov (United States)

    Setliff, Dorothy E.

    1992-01-01

    This paper presents research into providing highly reusable and maintainable components by using automatic software synthesis techniques. This proposal uses domain knowledge combined with automatic software synthesis techniques to engineer large-scale mission-critical real-time software. The hypothesis centers on a software synthesis architecture that specifically incorporates application-specific (in this case real-time) knowledge. This architecture synthesizes complex system software to meet a behavioral specification and external interaction design constraints. Some examples of these external constraints are communication protocols, precisions, timing, and space limitations. The incorporation of application-specific knowledge facilitates the generation of mathematical software metrics which are used to narrow the design space, thereby making software synthesis tractable. Success has the potential to dramatically reduce mission-critical system life-cycle costs not only by reducing development time, but more importantly facilitating maintenance, modifications, and extensions of complex mission-critical software systems, which are currently dominating life cycle costs.

  12. Systems and software quality the next step for industrialisation

    CERN Document Server

    Wieczorek, Martin; Bons, Heinz

    2014-01-01

    Software and systems quality is playing an increasingly important role in the growth of almost all - profit and non-profit - organisations. Quality is vital to the success of enterprises in their markets. Most small trade and repair businesses use software systems in their administration and marketing processes. Every doctor's surgery is managing its patients using software. Banking is no longer conceivable without software. Aircraft, trucks and cars use more and more software to handle their increasingly complex technical systems. Innovation, competition and cost pressure are always present i

  13. Tank monitor and control system (TMACS) software configuration management plan

    International Nuclear Information System (INIS)

    GLASSCOCK, J.A.

    1999-01-01

    This Software Configuration Management Plan (SCMP) describes the methodology for control of computer software developed and supported by the Systems Development and Integration (SD and I) organization of Lockheed Martin Services, Inc. (LMSI) for the Tank Monitor and Control System (TMACS). This plan controls changes to the software and configuration files used by TMACS. The controlled software includes the Gensym software package, Gensym knowledge base files developed for TMACS, C-language programs used by TMACS, the operating system on the production machine, language compilers, and all Windows NT commands and functions which affect the operating environment. The configuration files controlled include the files downloaded to the Acromag and Westronic field instruments

  14. System support software for TSTA [Tritium Systems Test Assembly

    International Nuclear Information System (INIS)

    Claborn, G.W.; Mann, L.W.; Nielson, C.W.

    1987-10-01

    The fact that Tritium Systems Test Assembly (TSTA) is an experimental facility makes it impossible and undesirable to try to forecast the exact software requirements. Thus the software had to be written in a manner that would allow modifications without compromising the safety requirements imposed by the handling of tritium. This suggested a multi-level approach to the software. In this approach (much like the ISO network model) each level is isolated from the level below and above by cleanly defined interfaces. For example, the subsystem support level interfaces with the subsystem hardware through the software support level. Routines in the software support level provide operations like ''OPEN VALVE'' and CLOSE VALVE'' to the subsystem level. This isolates the subsystem level from the actual hardware. This is advantageous because changes can occur in any level without the need for propagating the change to any other level. The TSTA control system consists of the hardware level, the data conversion level, the operator interface level, and the subsystem process level. These levels are described

  15. A measurement system for large, complex software programs

    Science.gov (United States)

    Rone, Kyle Y.; Olson, Kitty M.; Davis, Nathan E.

    1994-01-01

    This paper describes measurement systems required to forecast, measure, and control activities for large, complex software development and support programs. Initial software cost and quality analysis provides the foundation for meaningful management decisions as a project evolves. In modeling the cost and quality of software systems, the relationship between the functionality, quality, cost, and schedule of the product must be considered. This explicit relationship is dictated by the criticality of the software being developed. This balance between cost and quality is a viable software engineering trade-off throughout the life cycle. Therefore, the ability to accurately estimate the cost and quality of software systems is essential to providing reliable software on time and within budget. Software cost models relate the product error rate to the percent of the project labor that is required for independent verification and validation. The criticality of the software determines which cost model is used to estimate the labor required to develop the software. Software quality models yield an expected error discovery rate based on the software size, criticality, software development environment, and the level of competence of the project and developers with respect to the processes being employed.

  16. The contribution of instrumentation and control software to system reliability

    International Nuclear Information System (INIS)

    Fryer, M.O.

    1984-01-01

    Advanced instrumentation and control systems are usually implemented using computers that monitor the instrumentation and issue commands to control elements. The control commands are based on instrument readings and software control logic. The reliability of the total system will be affected by the software design. When comparing software designs, an evaluation of how each design can contribute to the reliability of the system is desirable. Unfortunately, the science of reliability assessment of combined hardware and software systems is in its infancy. Reliability assessment of combined hardware/software systems is often based on over-simplified assumptions about software behavior. A new method of reliability assessment of combined software/hardware systems is presented. The method is based on a procedure called fault tree analysis which determines how component failures can contribute to system failure. Fault tree analysis is a well developed method for reliability assessment of hardware systems and produces quantitative estimates of failure probability based on component failure rates. It is shown how software control logic can be mapped into a fault tree that depicts both software and hardware contributions to system failure. The new method is important because it provides a way for quantitatively evaluating the reliability contribution of software designs. In many applications, this can help guide designers in producing safer and more reliable systems. An application to the nuclear power research industry is discussed

  17. Modeling of Some Chaotic Systems with AnyLogic Software

    Directory of Open Access Journals (Sweden)

    Biljana Zlatanovska

    2018-05-01

    Full Text Available The chaotic systems are already known in the theory of chaos. In our paper will be analyzed the following chaotic systems: Rossler, Chua and Chen systems. All of them are systems of ordinary differential equations. By mathematical software Mathematica and MatLab, their graphical representation as continuous dynamical systems is already known. By computer simulations, via examples, the systems will be analyzed using AnyLogic software. We would like to present the way how ordinary differential equations are modeling with AnyLogic software, as one of the simplest software for use.

  18. Software Technology for Adaptable, Reliable Systems (STARS)

    Science.gov (United States)

    1994-03-25

    Tmeline(3), SECOMO(3), SEER(3), GSFC Software Engineering Lab Model(l), SLIM(4), SEER-SEM(l), SPQR (2), PRICE-S(2), internally-developed models(3), APMSS(1...3 " Timeline - 3 " SASET (Software Architecture Sizing Estimating Tool) - 2 " MicroMan 11- 2 * LCM (Logistics Cost Model) - 2 * SPQR - 2 * PRICE-S - 2

  19. One-Pot Automated Synthesis of Quasi Triblock Copolymers for Self-Healing Physically Crosslinked Hydrogels.

    Science.gov (United States)

    Voorhaar, Lenny; De Meyer, Bernhard; Du Prez, Filip; Hoogenboom, Richard

    2016-10-01

    The preparation of physically crosslinked hydrogels from quasi ABA-triblock copolymers with a water-soluble middle block and hydrophobic end groups is reported. The hydrophilic monomer N-acryloylmorpholine is copolymerized with hydrophobic isobornyl acrylate via a one-pot sequential monomer addition through reversible addition fragmentation chain-transfer (RAFT) polymerization in an automated parallel synthesizer, allowing systematic variation of polymer chain length and hydrophobic-hydrophilic ratio. Hydrophobic interactions between the outer blocks cause them to phase-separate into larger hydrophobic domains in water, forming physical crosslinks between the polymers. The resulting hydrogels are studied using rheology and their self-healing ability after large strain damage is shown. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Self-healing coatings based on halloysite clay polymer composites for protection of copper alloys.

    Science.gov (United States)

    Abdullayev, Elshad; Abbasov, Vagif; Tursunbayeva, Asel; Portnov, Vasiliy; Ibrahimov, Hikmat; Mukhtarova, Gulbaniz; Lvov, Yuri

    2013-05-22

    Halloysite clay nanotubes loaded with corrosion inhibitors benzotriazole (BTA), 2-mercaptobenzimidazole (MBI), and 2-mercaptobenzothiazole (MBT) were used as additives in self-healing composite paint coating of copper. These inhibitors form protective films on the metal surface and mitigate corrosion. Mechanisms involved in the film formation have been studied with optical and electron microscopy, UV-vis spectrometry, and adhesivity tests. Efficiency of the halloysite lumen loading ascended in the order of BTA halloysite formulations have shown the best protection. Inhibitors were kept in the tubes buried in polymeric paint layer for a long time and release was enhanced in the coating defects exposed to humid media with 20-50 h, sufficient for formation of protective layer. Anticorrosive performance of the halloysite-based composite acrylic and polyurethane coatings have been demonstrated for 110-copper alloy strips exposed to 0.5 M aqueous NaCl for 6 months.

  1. Dialing in the Ratio of Covalent and Coordination Cross-links in Self-healing Hydrogels

    DEFF Research Database (Denmark)

    Andersen, Amanda; Krogsgaard, Marie; Birkedal, Henrik

    ; it is of great interest to control the degree of which these are present; i.e. controlling the degree of catechol oxidation. Here, we report hydrogels in which the catechols participating in reversible (oxidation resistant catechol-analogue6) and irreversible oxidation cross-links are separated, enabling one...... to predefine the ratio of the two by altering the composition. The oxidation-resistant catechol-analogue was grafted onto polyallylamine,4 while the oxidation cross-links are introduced by addition of tannic acid that has the same useful properties as catechols.5,7,8 This affords hydrogels that retain self......-healing abilities even at high pH but that can be stiffened at will by dialing in the required degree of covalent crosslinking. This dial-in method thus harnesses two aspects of catechol-type chemistries to yield double network hydrogels in a straightforward and highly controllable manner....

  2. Microencapsulation of gallium-indium (Ga-In) liquid metal for self-healing applications.

    Science.gov (United States)

    Blaiszik, B J; Jones, A R; Sottos, N R; White, S R

    2014-01-01

    Microcapsules containing a liquid metal alloy core of gallium-indium (Ga-In) are prepared via in situ urea-formaldehyde (UF) microencapsulation. The capsule size, shape, thermal properties, and shell wall thickness are investigated. We prepare ellipsoidal capsules with major and minor diameter aspect ratios ranging from 1.64 to 1.08 and with major diameters ranging from 245 µm to 3 µm. We observe that as the capsule major diameter decreases, the aspect ratio approaches 1. The thermal properties of the prepared microcapsules are investigated by thermogravimetric (TGA) and differential scanning calorimetry (DSC). Microcapsules are shown to survive incorporation into an epoxy matrix and to trigger via mechanical damage to the cured matrix. Microcapsules containing liquid metal cores may have diverse applications ranging from self-healing to contrast enhancement or the demonstration of mechano-adaptive circuitry.

  3. Robust synthesis of epoxy resin-filled microcapsules for application to self-healing materials.

    Science.gov (United States)

    Bolimowski, Patryk A; Bond, Ian P; Wass, Duncan F

    2016-02-28

    Mechanically and thermally robust microcapsules containing diglycidyl ether bisphenol A-based epoxy resin and a high-boiling-point organic solvent were synthesized in high yield using in situ polymerization of urea and formaldehyde in an oil-in-water emulsion. Microcapsules were characterized in terms of their size and size distribution, shell surface morphology and thermal resistance to the curing cycles of commercially used epoxy polymers. The size distribution of the capsules and characteristics such as shell thickness can be controlled by the specific parameters of microencapsulation, including concentrations of reagents, stirrer speed and sonication. Selected microcapsules, and separated core and shell materials, were analysed using thermogravimetric analysis and differential scanning calorimetry. It is demonstrated that capsules lose minimal 2.5 wt% at temperatures no higher than 120°C. These microcapsules can be applied to self-healing carbon fibre composite structural materials, with preliminary results showing promising performance. © 2016 The Author(s).

  4. Self-healing of Micro-cracks in Engineered Cementitious Composites

    Directory of Open Access Journals (Sweden)

    Suryanto B.

    2015-12-01

    Full Text Available The performance of an Engineered Cementitious Composite (ECC to self-heal micro-cracks under a controlled laboratory environment is presented. Ten dog-bone shaped samples were prepared; five of them were preloaded to known strains and then left to heal in water in a temperature-controlled laboratory. Ultrasonic pulse velocity (UPV measurements were undertaken to monitor the crack-healing process. It was found that all samples exhibited recoveries in UPV and were able to recover to between 96.6% and 98% of their pre-test UPV values over a period of four weeks. An accelerated rate of healing was observed in the initial two-day period immediately following the preloading test.

  5. Wave-optics description of self-healing mechanism in Bessel beams.

    Science.gov (United States)

    Aiello, Andrea; Agarwal, Girish S

    2014-12-15

    Bessel beams' great importance in optics lies in that these propagate without spreading and can reconstruct themselves behind an obstruction placed across their path. However, a rigorous wave-optics explanation of the latter property is missing. In this work, we study the reconstruction mechanism by means of a wave-optics description. We obtain expressions for the minimum distance beyond the obstruction at which the beam reconstructs itself, which are in close agreement with the traditional one determined from geometrical optics. Our results show that the physics underlying the self-healing mechanism can be entirely explained in terms of the propagation of plane waves with radial wave vectors lying on a ring.

  6. Conformation-Directed Formation of Self-Healing Diblock Copolypeptide Hydrogels via Polyion Complexation.

    Science.gov (United States)

    Sun, Yintao; Wollenberg, Alexander L; O'Shea, Timothy Mark; Cui, Yanxiang; Zhou, Z Hong; Sofroniew, Michael V; Deming, Timothy J

    2017-10-25

    Synthetic diblock copolypeptides were designed to incorporate oppositely charged ionic segments that form β-sheet-structured hydrogel assemblies via polyion complexation when mixed in aqueous media. The observed chain conformation directed assembly was found to be required for efficient hydrogel formation and provided distinct and useful properties to these hydrogels, including self-healing after deformation, microporous architecture, and stability against dilution in aqueous media. While many promising self-assembled materials have been prepared using disordered or liquid coacervate polyion complex (PIC) assemblies, the use of ordered chain conformations in PIC assemblies to direct formation of new supramolecular morphologies is unprecedented. The promising attributes and unique features of the β-sheet-structured PIC hydrogels described here highlight the potential of harnessing conformational order derived from PIC assembly to create new supramolecular materials.

  7. Progressive retry for software error recovery in distributed systems

    Science.gov (United States)

    Wang, Yi-Min; Huang, Yennun; Fuchs, W. K.

    1993-01-01

    In this paper, we describe a method of execution retry for bypassing software errors based on checkpointing, rollback, message reordering and replaying. We demonstrate how rollback techniques, previously developed for transient hardware failure recovery, can also be used to recover from software faults by exploiting message reordering to bypass software errors. Our approach intentionally increases the degree of nondeterminism and the scope of rollback when a previous retry fails. Examples from our experience with telecommunications software systems illustrate the benefits of the scheme.

  8. Telemetry and Science Data Software System

    Science.gov (United States)

    Bates, Lakesha; Hong, Liang

    2011-01-01

    The Telemetry and Science Data Software System (TSDSS) was designed to validate the operational health of a spacecraft, ease test verification, assist in debugging system anomalies, and provide trending data and advanced science analysis. In doing so, the system parses, processes, and organizes raw data from the Aquarius instrument both on the ground and while in space. In addition, it provides a user-friendly telemetry viewer, and an instant pushbutton test report generator. Existing ground data systems can parse and provide simple data processing, but have limitations in advanced science analysis and instant report generation. The TSDSS functions as an offline data analysis system during I&T (integration and test) and mission operations phases. After raw data are downloaded from an instrument, TSDSS ingests the data files, parses, converts telemetry to engineering units, and applies advanced algorithms to produce science level 0, 1, and 2 data products. Meanwhile, it automatically schedules upload of the raw data to a remote server and archives all intermediate and final values in a MySQL database in time order. All data saved in the system can be straightforwardly retrieved, exported, and migrated. Using TSDSS s interactive data visualization tool, a user can conveniently choose any combination and mathematical computation of interesting telemetry points from a large range of time periods (life cycle of mission ground data and mission operations testing), and display a graphical and statistical view of the data. With this graphical user interface (GUI), the data queried graphs can be exported and saved in multiple formats. This GUI is especially useful in trending data analysis, debugging anomalies, and advanced data analysis. At the request of the user, mission-specific instrument performance assessment reports can be generated with a simple click of a button on the GUI. From instrument level to observatory level, the TSDSS has been operating supporting

  9. Software V ampersand V methods for digital plant protection system

    International Nuclear Information System (INIS)

    Kim, Hung-Jun; Han, Jai-Bok; Chun, Chong-Son; Kim, Sung; Kim, Kern-Joong.

    1997-01-01

    Careful thought must be given to software design in the development of digital based systems that play a critical role in the successful operation of nuclear power plants. To evaluate the software verification and validation methods as well as to verify its system performance capabilities for the upgrade instrumentation and control system in the Korean future nuclear power plants, the prototype Digital Plant, Protection System (DPPS) based on the Programmable Logic Controller (PLC) has been constructed. The system design description and features are briefly presented, and the software design and software verification and validation methods are focused. 6 refs., 2 figs

  10. A control system verifier using automated reasoning software

    International Nuclear Information System (INIS)

    Smith, D.E.; Seeman, S.E.

    1985-08-01

    An on-line, automated reasoning software system for verifying the actions of other software or human control systems has been developed. It was demonstrated by verifying the actions of an automated procedure generation system. The verifier uses an interactive theorem prover as its inference engine with the rules included as logical axioms. Operation of the verifier is generally transparent except when the verifier disagrees with the actions of the monitored software. Testing with an automated procedure generation system demonstrates the successful application of automated reasoning software for verification of logical actions in a diverse, redundant manner. A higher degree of confidence may be placed in the verified actions of the combined system

  11. Self-healing of mechanically-loaded self consolidating concretes with high volumes of fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Mustafa Sahmaran; Suleyman B. Keskin; Gozde Ozerkan; Ismail O. Yaman [University of Gaziantep, Gaziantep (Turkey). Department of Civil Engineering

    2008-11-15

    This article discusses the effects of self-healing on self consolidating concretes incorporating high volumes of fly ash (HVFA-SCC) when subjected to continuous water exposure. For this purpose, self consolidating concretes with fly ash replacement ratios of 0%, 35%, and 55% were prepared having a constant water-cementitious material ratio of 0.35. A uniaxial compression load was applied to generate microcracks in concrete where cylindrical specimens were pre-loaded up to 70% and 90% of the ultimate compressive load determined at 28 days. Later, the extent of damage was determined as percentage of loss in mechanical properties and percentage of increase in permeation properties. After pre-loading, concrete specimens were stored in water for a month and the mechanical and permeation properties are monitored at every two weeks. It was observed that HVFA-SCC mixtures initially lost 27% of their strength when pre-loaded up to 90% of their ultimate strength, and after 30 days of water curing that reduction was only 7%, indicating a substantial healing. On the other hand, for SCC specimens without fly ash that were pre-loaded to the same level, the loss in strength was initially 19%, and after a month of moist curing it was only 13%. Similar observations were also made on the permeation properties with greater effects. As the HVFA-SCCs studied have an important amount of unhydrated fly ash available in their microstructure, these observations are attributed to the self-healing of the pre-existing cracks, mainly by hydration of anhydrous fly ash particles on the crack surfaces.

  12. Summary of the International Conference on Software and System Processes

    DEFF Research Database (Denmark)

    Kuhrmann, Marco; O'Connor, Rory V.; Perry, Dewayne E.

    2016-01-01

    The International Conference on Software and Systems Process (ICSSP), continuing the success of Software Process Workshop (SPW), the Software Process Modeling and Simulation Workshop (ProSim) and the International Conference on Software Process (ICSP) conference series, has become the established...... premier event in the field of software and systems engineering processes. It provides a leading forum for the exchange of research outcomes and industrial best-practices in process development from software and systems disciplines. ICSSP 2016 was held in Austin, Texas, from 14-15 May 2016, co......-located with the 38th International Conference on Software Engineering (ICSE). The theme of mICSSP 2016 was studying "Process(es) in Action" by recognizing that the AS-Planned and AS-Practiced processes can be quite different in many ways including their ows, their complexity and the evolving needs of stakeholders...

  13. Integration of the Self-Healing eDNA Architecture in a Liquid Crystal Waveguide-based Fourier Transform Spectrometer

    DEFF Research Database (Denmark)

    Boesen, Michael Reibel; Keymeulen, D.; Madsen, Jan

    2011-01-01

    In this work we describe the first real world case study for the self-healing eDNA (electronic DNA) architecture by implementing the control and data processing of a Fourier Transform Spectrometer (FTS) on an eDNA prototype. For this purpose the eDNA prototype has been ported from a Xilinx Virtex 5...

  14. Self-healing anticorrosive organic coating based on an encapsulated water reactive silyl ester: synthesis and proof of concept

    NARCIS (Netherlands)

    García, S.J.; Fischer, H.R.; White, P.A.; Mardel, J.; González-García, Y.; Mol, J.M.C.; Hughes, A.E.

    2011-01-01

    In this paper a self-healing anticorrosive organic coating based on an encapsulated water reactive organic agent is presented. A reactive silyl ester is proposed as a new organic reactive healing agent and its synthesis, performance, incorporation into an organic coating and evaluation of

  15. Field application of self-healing concrete with natural fibres as linings for irrigation canals in Ecuador

    NARCIS (Netherlands)

    Sierra Beltran, M.G.; Jonkers, H.M.; Mors, R.M.; Mera-Ortiz, W.

    2015-01-01

    This paper describes the first field application of self-healing concrete with alkaliphilic spore-forming bacteria and reinforced with natural fibres. The application took place in the highlands in Ecuador in July 2014. The concrete was cast as linings for an irrigation canal that transports water

  16. Self-Healing Capability of Fiber-Reinforced Cementitious Composites for Recovery of Watertightness and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Tomoya Nishiwaki

    2014-03-01

    Full Text Available Various types of fiber reinforced cementitious composites (FRCCs were experimentally studied to evaluate their self-healing capabilities regarding their watertightness and mechanical properties. Cracks were induced in the FRCC specimens during a tensile loading test, and the specimens were then immersed in static water for self-healing. By water permeability and reloading tests, it was determined that the FRCCs containing synthetic fiber and cracks of width within a certain range (<0.1 mm exhibited good self-healing capabilities regarding their watertightness. Particularly, the high polarity of the synthetic fiber (polyvinyl alcohol (PVA series and hybrid fiber reinforcing (polyethylene (PE and steel code (SC series showed high recovery ratio. Moreover, these series also showed high potential of self-healing of mechanical properties. It was confirmed that recovery of mechanical property could be obtained only in case when crack width was sufficiently narrow, both the visible surface cracks and the very fine cracks around the bridging of the SC fibers. Recovery of the bond strength by filling of the very fine cracks around the bridging fibers enhanced the recovery of the mechanical property.

  17. Improving the self-healing properties of concrete materials by using composite actions with fiber reinforced polymers.

    Science.gov (United States)

    2013-06-01

    This research study is motivated by the need to reduce the costs of maintenance and repair of the aging transportation infrastructure in the US. The proposed approach is to use self-healing concrete. The objectives of this study were: (1) to evaluate...

  18. Novel antifouling self-healing poly(carboxybetaine methacrylamide-co-HEMA) nanocomposite hydrogels with superior mechanical properties

    NARCIS (Netherlands)

    Kostina, Nina Yu.; Sharifi, Shahriar; Pereira, Andres de los Santos; Michalek, Jiri; Grijpma, Dirk W.; Rodriguez-Emmenegger, Cesar

    2013-01-01

    Novel antifouling highly wettable hydrogels with superior mechanical and self-healing properties are presented. Hydrogels were prepared by UV-initiated copolymerisation of non-fouling zwitterionic carboxybetaine methacrylamide (CBMAA-3) and 2-hydroxyethyl methacrylate (HEMA) in the presence of

  19. Morphing Metal and Elastomer Bicontinuous Foams for Reversible Stiffness, Shape Memory, and Self-Healing Soft Machines.

    Science.gov (United States)

    Van Meerbeek, Ilse M; Mac Murray, Benjamin C; Kim, Jae Woo; Robinson, Sanlin S; Zou, Perry X; Silberstein, Meredith N; Shepherd, Robert F

    2016-04-13

    A metal-elastomer-foam composite that varies in stiffness, that can change shape and store shape memory, that self-heals, and that welds into monolithic structures from smaller components is presented. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Dilute self-healing hydrogels of silk-collagen-like block copolypeptides at neutral pH

    NARCIS (Netherlands)

    Golinska, M.D.; Wlodarczyk-Biegun, M.K.; Werten, M.W.T.; Cohen Stuart, M.A.; Wolf, de F.A.; Vries, de R.J.

    2014-01-01

    We report on self-healing, pH-responsive hydrogels that are entirely protein-based. The protein is a denovo designed recombinant triblock polypeptide of 66 kg/mol consisting of a silk-like middle block (GAGAGAGH)48, flanked by two long collagen-inspired hydrophilic random coil side blocks. The

  1. Design of Self-Healing Supramolecular Rubbers by Introducing Ionic Cross-Links into Natural Rubber via a Controlled Vulcanization.

    Science.gov (United States)

    Xu, Chuanhui; Cao, Liming; Lin, Baofeng; Liang, Xingquan; Chen, Yukun

    2016-07-13

    Introducing ionic associations is one of the most effective approaches to realize a self-healing behavior for rubbers. However, most of commercial rubbers are nonpolar rubbers without now available functional groups to be converted into ionic groups. In this paper, our strategy was based on a controlled peroxide-induced vulcanization to generate massive ionic cross-links via polymerization of zinc dimethacrylate (ZDMA) in natural rubber (NR) and exploited it as a potential self-healable material. We controlled vulcanization process to retard the formation of covalent cross-link network, and successfully generated a reversible supramolecular network mainly constructed by ionic cross-links. Without the restriction of covalent cross-linkings, the NR chains in ionic supramolecular network had good flexibility and mobility. The nature that the ionic cross-links was easily reconstructed and rearranged facilitating the self-healing behavior, thereby enabling a fully cut sample to rejoin and retain to its original properties after a suitable self-healing process at ambient temperature. This study thus demonstrates a feasible approach to impart an ionic association induced self-healing function to commercial rubbers without ionic functional groups.

  2. Contributions of hard and soft blocks in the self-healing of metal-ligand-containing block copolymers

    NARCIS (Netherlands)

    Bose, Ranjita K.; Enke, Marcel; Grande, Antonio M.; Zechel, Stefan; Schacher, Felix H.; Hager, Martin D.; Garcia, Santiago J.; Schubert, Ulrich S.; van der Zwaag, Sybrand

    2017-01-01

    The main aim of this work is to study the respective contribution of the hard and soft blocks of a metal-ligand containing block copolymer to the self-healing behavior. To this aim, different block copolymers containing terpyridine were synthesized using reversible addition-fragmentation chain

  3. Contributions of hard and soft blocks in the self-healing of metal-ligand-containing block copolymers

    NARCIS (Netherlands)

    Bose, R.K.; Enke, Marcel; Grande, A.M.; Zechel, Stefan; Schacher, Felix H.; Hager, Martin D.; Garcia Espallargas, Santiago J.; Schubert, Ulrich S.; van der Zwaag, S.

    2017-01-01

    The main aim of this work is to study the respective contribution of the hard and soft blocks of a metal-ligand containing block copolymer to the self-healing behavior. To this aim, different block copolymers containing terpyridine were synthesized using reversible addition-fragmentation chain

  4. Software Engineering Laboratory (SEL) data base reporting software user's guide and system description. Volume 1: Introduction and user's guide

    Science.gov (United States)

    1983-01-01

    Reporting software programs provide formatted listings and summary reports of the Software Engineering Laboratory (SEL) data base contents. The operating procedures and system information for 18 different reporting software programs are described. Sample output reports from each program are provided.

  5. SWEPP Gamma-Ray Spectrometer System software design description

    International Nuclear Information System (INIS)

    Femec, D.A.; Killian, E.W.

    1994-08-01

    To assist in the characterization of the radiological contents of contract-handled waste containers at the Stored Waste Examination Pilot Plant (SWEPP), the SWEPP Gamma-Ray Spectrometer (SGRS) System has been developed by the Radiation Measurements and Development Unit of the Idaho National Engineering Laboratory. The SGRS system software controls turntable and detector system activities. In addition to determining the concentrations of gamma-ray-emitting radionuclides, this software also calculates attenuation-corrected isotopic mass ratios of-specific interest. This document describes the software design for the data acquisition and analysis software associated with the SGRS system

  6. SWEPP Gamma-Ray Spectrometer System software design description

    Energy Technology Data Exchange (ETDEWEB)

    Femec, D.A.; Killian, E.W.

    1994-08-01

    To assist in the characterization of the radiological contents of contract-handled waste containers at the Stored Waste Examination Pilot Plant (SWEPP), the SWEPP Gamma-Ray Spectrometer (SGRS) System has been developed by the Radiation Measurements and Development Unit of the Idaho National Engineering Laboratory. The SGRS system software controls turntable and detector system activities. In addition to determining the concentrations of gamma-ray-emitting radionuclides, this software also calculates attenuation-corrected isotopic mass ratios of-specific interest. This document describes the software design for the data acquisition and analysis software associated with the SGRS system.

  7. Software Defined Common Processing System (SDCPS), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Coherent Logix, Incorporated (CLX) proposes the development of a Software Defined Common Processing System (SDCPS) that leverages the inherent advantages of an...

  8. Analyzing Software Requirements Errors in Safety-Critical, Embedded Systems

    Science.gov (United States)

    Lutz, Robyn R.

    1993-01-01

    This paper analyzes the root causes of safety-related software errors in safety-critical, embedded systems. The results show that software errors identified as potentially hazardous to the system tend to be produced by different error mechanisms than non- safety-related software errors. Safety-related software errors are shown to arise most commonly from (1) discrepancies between the documented requirements specifications and the requirements needed for correct functioning of the system and (2) misunderstandings of the software's interface with the rest of the system. The paper uses these results to identify methods by which requirements errors can be prevented. The goal is to reduce safety-related software errors and to enhance the safety of complex, embedded systems.

  9. Flight test of a resident backup software system

    Science.gov (United States)

    Deets, Dwain A.; Lock, Wilton P.; Megna, Vincent A.

    1987-01-01

    A new fault-tolerant system software concept employing the primary digital computers as host for the backup software portion has been implemented and flight tested in the F-8 digital fly-by-wire airplane. The system was implemented in such a way that essentially no transients occurred in transferring from primary to backup software. This was accomplished without a significant increase in the complexity of the backup software. The primary digital system was frame synchronized, which provided several advantages in implementing the resident backup software system. Since the time of the flight tests, two other flight vehicle programs have made a commitment to incorporate resident backup software similar in nature to the system described here.

  10. User and system considerations for the TCSTEK software library

    International Nuclear Information System (INIS)

    Gray, W.H.

    1979-08-01

    This report documents the idiosyncrasies of the Tektronix PLOT 10 Terminal Control System level 3.3 software as it currently exists on the ORNL Fusion Energy Division DECsystem-10 computer. It is intended to serve as a reference for future Terminal Control System updates in order that continuity between releases of Terminal Control System PLOT 10 software may be maintained

  11. 36 CFR 1194.21 - Software applications and operating systems.

    Science.gov (United States)

    2010-07-01

    ... operating systems. 1194.21 Section 1194.21 Parks, Forests, and Public Property ARCHITECTURAL AND... Standards § 1194.21 Software applications and operating systems. (a) When software is designed to run on a... shall not disrupt or disable activated features of any operating system that are identified as...

  12. User and system considerations for the TCSTEK software library

    Energy Technology Data Exchange (ETDEWEB)

    Gray, W.H.

    1979-08-01

    This report documents the idiosyncrasies of the Tektronix PLOT 10 Terminal Control System level 3.3 software as it currently exists on the ORNL Fusion Energy Division DECsystem-10 computer. It is intended to serve as a reference for future Terminal Control System updates in order that continuity between releases of Terminal Control System PLOT 10 software may be maintained.

  13. Digital image processing software system using an array processor

    International Nuclear Information System (INIS)

    Sherwood, R.J.; Portnoff, M.R.; Journeay, C.H.; Twogood, R.E.

    1981-01-01

    A versatile array processor-based system for general-purpose image processing was developed. At the heart of this system is an extensive, flexible software package that incorporates the array processor for effective interactive image processing. The software system is described in detail, and its application to a diverse set of applications at LLNL is briefly discussed. 4 figures, 1 table

  14. Ultrasensitive Wearable Soft Strain Sensors of Conductive, Self-healing, and Elastic Hydrogels with Synergistic "Soft and Hard" Hybrid Networks.

    Science.gov (United States)

    Liu, Yan-Jun; Cao, Wen-Tao; Ma, Ming-Guo; Wan, Pengbo

    2017-08-02

    Robust, stretchable, and strain-sensitive hydrogels have recently attracted immense research interest because of their potential application in wearable strain sensors. The integration of the synergistic characteristics of decent mechanical properties, reliable self-healing capability, and high sensing sensitivity for fabricating conductive, elastic, self-healing, and strain-sensitive hydrogels is still a great challenge. Inspired by the mechanically excellent and self-healing biological soft tissues with hierarchical network structures, herein, functional network hydrogels are fabricated by the interconnection between a "soft" homogeneous polymer network and a "hard" dynamic ferric (Fe 3+ ) cross-linked cellulose nanocrystals (CNCs-Fe 3+ ) network. Under stress, the dynamic CNCs-Fe 3+ coordination bonds act as sacrificial bonds to efficiently dissipate energy, while the homogeneous polymer network leads to a smooth stress-transfer, which enables the hydrogels to achieve unusual mechanical properties, such as excellent mechanical strength, robust toughness, and stretchability, as well as good self-recovery property. The hydrogels demonstrate autonomously self-healing capability in only 5 min without the need of any stimuli or healing agents, ascribing to the reorganization of CNCs and Fe 3+ via ionic coordination. Furthermore, the resulted hydrogels display tunable electromechanical behavior with sensitive, stable, and repeatable variations in resistance upon mechanical deformations. Based on the tunable electromechanical behavior, the hydrogels can act as a wearable strain sensor to monitor finger joint motions, breathing, and even the slight blood pulse. This strategy of building synergistic "soft and hard" structures is successful to integrate the decent mechanical properties, reliable self-healing capability, and high sensing sensitivity together for assembling a high-performance, flexible, and wearable strain sensor.

  15. Software reliability growth model for safety systems of nuclear reactor

    International Nuclear Information System (INIS)

    Thirugnana Murthy, D.; Murali, N.; Sridevi, T.; Satya Murty, S.A.V.; Velusamy, K.

    2014-01-01

    The demand for complex software systems has increased more rapidly than the ability to design, implement, test, and maintain them, and the reliability of software systems has become a major concern for our, modern society.Software failures have impaired several high visibility programs in space, telecommunications, defense and health industries. Besides the costs involved, it setback the projects. The ways of quantifying it and using it for improvement and control of the software development and maintenance process. This paper discusses need for systematic approaches for measuring and assuring software reliability which is a major share of project development resources. It covers the reliability models with the concern on 'Reliability Growth'. It includes data collection on reliability, statistical estimation and prediction, metrics and attributes of product architecture, design, software development, and the operational environment. Besides its use for operational decisions like deployment, it includes guiding software architecture, development, testing and verification and validation. (author)

  16. Compiling software for a hierarchical distributed processing system

    Science.gov (United States)

    Archer, Charles J; Blocksome, Michael A; Ratterman, Joseph D; Smith, Brian E

    2013-12-31

    Compiling software for a hierarchical distributed processing system including providing to one or more compiling nodes software to be compiled, wherein at least a portion of the software to be compiled is to be executed by one or more nodes; compiling, by the compiling node, the software; maintaining, by the compiling node, any compiled software to be executed on the compiling node; selecting, by the compiling node, one or more nodes in a next tier of the hierarchy of the distributed processing system in dependence upon whether any compiled software is for the selected node or the selected node's descendents; sending to the selected node only the compiled software to be executed by the selected node or selected node's descendent.

  17. A fault-tolerant software strategy for digital systems

    Science.gov (United States)

    Hitt, E. F.; Webb, J. J.

    1984-01-01

    Techniques developed for producing fault-tolerant software are described. Tolerance is required because of the impossibility of defining fault-free software. Faults are caused by humans and can appear anywhere in the software life cycle. Tolerance is effected through error detection, damage assessment, recovery, and fault treatment, followed by return of the system to service. Multiversion software comprises two or more versions of the software yielding solutions which are examined by a decision algorithm. Errors can also be detected by extrapolation from previous results or by the acceptability of results. Violations of timing specifications can reveal errors, or the system can roll back to an error-free state when a defect is detected. The software, when used in flight control systems, must not impinge on time-critical responses. Efforts are still needed to reduce the costs of developing the fault-tolerant systems.

  18. Model-driven dependability assessment of software systems

    CERN Document Server

    Bernardi, Simona; Petriu, Dorina C

    2013-01-01

    In this book, the authors present cutting-edge model-driven techniques for modeling and analysis of software dependability. Most of them are based on the use of UML as software specification language. From the software system specification point of view, such techniques exploit the standard extension mechanisms of UML (i.e., UML profiling). UML profiles enable software engineers to add non-functional properties to the software model, in addition to the functional ones. The authors detail the state of the art on UML profile proposals for dependability specification and rigorously describe the t

  19. Storage system software solutions for high-end user needs

    Science.gov (United States)

    Hogan, Carole B.

    1992-01-01

    Today's high-end storage user is one that requires rapid access to a reliable terabyte-capacity storage system running in a distributed environment. This paper discusses conventional storage system software and concludes that this software, designed for other purposes, cannot meet high-end storage requirements. The paper also reviews the philosophy and design of evolving storage system software. It concludes that this new software, designed with high-end requirements in mind, provides the potential for solving not only the storage needs of today but those of the foreseeable future as well.

  20. Training Requirements and Information Management System. Software user guide

    Energy Technology Data Exchange (ETDEWEB)

    Cillan, T.F.; Hodgson, M.A.

    1992-05-01

    This is the software user`s guide for the Training Requirements and Information Management System. This guide defines and describes the software operating procedures as they apply to the end user of the software program. This guide is intended as a reference tool for the user who already has an indepth knowledge of the Training Requirements and Information Management System functions and data reporting requirement.

  1. Advanced information processing system: Input/output network management software

    Science.gov (United States)

    Nagle, Gail; Alger, Linda; Kemp, Alexander

    1988-01-01

    The purpose of this document is to provide the software requirements and specifications for the Input/Output Network Management Services for the Advanced Information Processing System. This introduction and overview section is provided to briefly outline the overall architecture and software requirements of the AIPS system before discussing the details of the design requirements and specifications of the AIPS I/O Network Management software. A brief overview of the AIPS architecture followed by a more detailed description of the network architecture.

  2. Modernization of tank floor scanning system (TAFLOSS) software

    International Nuclear Information System (INIS)

    Mohd Fitri Abdul Rahman; Jaafar Abdullah; Susan Maria Sipaun

    2002-01-01

    Tank Floor Scanning System (TAFLOSS) is a portable nucleonic device based on the scattering and moderation phenomena of neutrons. TAFLOSS, which was developed by MINT, can precisely and non-destructively measure the gap and hydrogen content in the foundation of a gigantic industrial tank in a practical and cost-effective manner. In recording and analysing measured data, three different computer software were used. In analysing the initial data, a Disk Operating System (DOS) based software called MesTank 3.0 have been developed. The system also used commercial software such as Table Curve 2D and SURFER for graphics purposes. Table Curve 2D was used to plot and evaluate curve fitting, whereas SURFER software used to draw contours. It is not user friendly and time consuming to switch from a software to another software for different tasks of this system. Therefore, the main objective of the project is to develop new user-friendly software that combined the old and commercial software into a single package. The computer programming language that was used to develop the software is Microsoft Visual C++ ver. 6.0. The process of developing this software involved complex mathematical calculation, curve fitting and contour plot. This paper describes the initial development of a computer programme for analysing the initial data and plotting exponential curve fitting. (Author)

  3. ISWHM: Tools and Techniques for Software and System Health Management

    Science.gov (United States)

    Schumann, Johann; Mengshoel, Ole J.; Darwiche, Adnan

    2010-01-01

    This presentation presents status and results of research on Software Health Management done within the NRA "ISWHM: Tools and Techniques for Software and System Health Management." Topics include: Ingredients of a Guidance, Navigation, and Control System (GN and C); Selected GN and C Testbed example; Health Management of major ingredients; ISWHM testbed architecture; and Conclusions and next Steps.

  4. Software for MR imaging system VISTA-E50

    International Nuclear Information System (INIS)

    Nakatao, Shirou; Iino, Mitsutoshi; Fukuda, Kazuhiko

    1989-01-01

    VISTA-E50 has the advantages of high-quality imaging, fast scanning, high patient throughput and easy operation featured by AI (artificial intelligence) technologies, as well as merits of compact, light-weight, space- and energy-saving system. This paper presents system software and clinical application software of VISTA-E50, especially for each function and advantage. (author)

  5. Environmental Control System Software & Hardware Development

    Science.gov (United States)

    Vargas, Daniel Eduardo

    2017-01-01

    ECS hardware: (1) Provides controlled purge to SLS Rocket and Orion spacecraft. (2) Provide mission-focused engineering products and services. ECS software: (1) NASA requires Compact Unique Identifiers (CUIs); fixed-length identifier used to identify information items. (2) CUI structure; composed of nine semantic fields that aid the user in recognizing its purpose.

  6. New control system: ADA softwares organization

    International Nuclear Information System (INIS)

    David, L.

    1992-01-01

    On VAX/VMS, ADA compiler is integrated in a workshop of ACS software engineering which allows a coherent development by control of source and executable programs, by separation of applications in various levels of visibility and by management of existing links between different modules of a same application. (A.B.)

  7. Artificial intelligence and expert systems in-flight software testing

    Science.gov (United States)

    Demasie, M. P.; Muratore, J. F.

    1991-01-01

    The authors discuss the introduction of advanced information systems technologies such as artificial intelligence, expert systems, and advanced human-computer interfaces directly into Space Shuttle software engineering. The reconfiguration automation project (RAP) was initiated to coordinate this move towards 1990s software technology. The idea behind RAP is to automate several phases of the flight software testing procedure and to introduce AI and ES into space shuttle flight software testing. In the first phase of RAP, conventional tools to automate regression testing have already been developed or acquired. There are currently three tools in use.

  8. An Agent Based Software Approach towards Building Complex Systems

    Directory of Open Access Journals (Sweden)

    Latika Kharb

    2015-08-01

    Full Text Available Agent-oriented techniques represent an exciting new means of analyzing, designing and building complex software systems. They have the potential to significantly improve current practice in software engineering and to extend the range of applications that can feasibly be tackled. Yet, to date, there have been few serious attempts to cast agent systems as a software engineering paradigm. This paper seeks to rectify this omission. Specifically, points to be argued include:firstly, the conceptual apparatus of agent-oriented systems is well-suited to building software solutions for complex systems and secondly, agent-oriented approaches represent a genuine advance over the current state of the art for engineering complex systems. Following on from this view, the major issues raised by adopting an agentoriented approach to software engineering are highlighted and discussed in this paper.

  9. Advanced transport operating system software upgrade: Flight management/flight controls software description

    Science.gov (United States)

    Clinedinst, Winston C.; Debure, Kelly R.; Dickson, Richard W.; Heaphy, William J.; Parks, Mark A.; Slominski, Christopher J.; Wolverton, David A.

    1988-01-01

    The Flight Management/Flight Controls (FM/FC) software for the Norden 2 (PDP-11/70M) computer installed on the NASA 737 aircraft is described. The software computes the navigation position estimates, guidance commands, those commands to be issued to the control surfaces to direct the aircraft in flight based on the modes selected on the Advanced Guidance Control System (AGSC) mode panel, and the flight path selected via the Navigation Control/Display Unit (NCDU).

  10. The software design of area γ radiation monitoring system

    International Nuclear Information System (INIS)

    Song Chenxin; Deng Changming; Cheng Chang; Ren Yi; Meng Dan; Liu Yun

    2007-01-01

    This paper main introduction the system structure, software architecture, design ideas of the area γ radiation monitoring system. Detailed introduction some programming technology about the computer communication with the local display unit. (authors)

  11. The software design of area γ radiation monitoring system

    International Nuclear Information System (INIS)

    Song Chenxin; Deng Changming; Cheng Chang; Ren Yi; Meng Dan; Liu Yun

    2008-01-01

    This paper main introduction the system structure, software architecture, design ideas of the area γ radiation monitoring system. Detailed introduction some programming technology about the computer communication with the local display unit. (authors)

  12. Research and Development on Food Nutrition Statistical Analysis Software System

    OpenAIRE

    Du Li; Ke Yun

    2013-01-01

    Designing and developing a set of food nutrition component statistical analysis software can realize the automation of nutrition calculation, improve the nutrition processional professional’s working efficiency and achieve the informatization of the nutrition propaganda and education. In the software development process, the software engineering method and database technology are used to calculate the human daily nutritional intake and the intelligent system is used to evaluate the user’s hea...

  13. TAP II Beamforming System Software Final Report

    Science.gov (United States)

    1977-05-01

    recommended. Ten averages may be sufficient for some wave studies . 2.3.1.4 (U) The TYPE OF WEIGHTING WINDOW is selected according to the characteristics...and FIFF1T), the AP s ource code assembler (APAL), the AP Simulator ( APSIM ), and the AP software Debug program (IIWDBUG). UNCLASSIFiED...PROCESSING. Thia is a moderately complex pro gram uhich utilizes the AP-120B array processor. For detailed descrip- "tion of the process, study of the

  14. Statistical reliability assessment of software-based systems

    International Nuclear Information System (INIS)

    Korhonen, J.; Pulkkinen, U.; Haapanen, P.

    1997-01-01

    Plant vendors nowadays propose software-based systems even for the most critical safety functions. The reliability estimation of safety critical software-based systems is difficult since the conventional modeling techniques do not necessarily apply to the analysis of these systems, and the quantification seems to be impossible. Due to lack of operational experience and due to the nature of software faults, the conventional reliability estimation methods can not be applied. New methods are therefore needed for the safety assessment of software-based systems. In the research project Programmable automation systems in nuclear power plants (OHA), financed together by the Finnish Centre for Radiation and Nuclear Safety (STUK), the Ministry of Trade and Industry and the Technical Research Centre of Finland (VTT), various safety assessment methods and tools for software based systems are developed and evaluated. This volume in the OHA-report series deals with the statistical reliability assessment of software based systems on the basis of dynamic test results and qualitative evidence from the system design process. Other reports to be published later on in OHA-report series will handle the diversity requirements in safety critical software-based systems, generation of test data from operational profiles and handling of programmable automation in plant PSA-studies. (orig.) (25 refs.)

  15. Testing digital safety system software with a testability measure based on a software fault tree

    International Nuclear Information System (INIS)

    Sohn, Se Do; Hyun Seong, Poong

    2006-01-01

    Using predeveloped software, a digital safety system is designed that meets the quality standards of a safety system. To demonstrate the quality, the design process and operating history of the product are reviewed along with configuration management practices. The application software of the safety system is developed in accordance with the planned life cycle. Testing, which is a major phase that takes a significant time in the overall life cycle, can be optimized if the testability of the software can be evaluated. The proposed testability measure of the software is based on the entropy of the importance of basic statements and the failure probability from a software fault tree. To calculate testability, a fault tree is used in the analysis of a source code. With a quantitative measure of testability, testing can be optimized. The proposed testability can also be used to demonstrate whether the test cases based on uniform partitions, such as branch coverage criteria, result in homogeneous partitions that is known to be more effective than random testing. In this paper, the testability measure is calculated for the modules of a nuclear power plant's safety software. The module testing with branch coverage criteria required fewer test cases if the module has higher testability. The result shows that the testability measure can be used to evaluate whether partitions have homogeneous characteristics

  16. Simulation software support (S3) system a software testing and debugging tool

    International Nuclear Information System (INIS)

    Burgess, D.C.; Mahjouri, F.S.

    1990-01-01

    The largest percentage of technical effort in the software development process is accounted for debugging and testing. It is not unusual for a software development organization to spend over 50% of the total project effort on testing. In the extreme, testing of human-rated software (e.g., nuclear reactor monitoring, training simulator) can cost three to five times as much as all other software engineering steps combined. The Simulation Software Support (S 3 ) System, developed by the Link-Miles Simulation Corporation is ideally suited for real-time simulation applications which involve a large database with models programmed in FORTRAN. This paper will focus on testing elements of the S 3 system. In this paper system support software utilities are provided which enable the loading and execution of modules in the development environment. These elements include the Linking/Loader (LLD) for dynamically linking program modules and loading them into memory and the interactive executive (IEXEC) for controlling the execution of the modules. Features of the Interactive Symbolic Debugger (SD) and the Real Time Executive (RTEXEC) to support the unit and integrated testing will be explored

  17. Software reliability and safety in nuclear reactor protection systems

    International Nuclear Information System (INIS)

    Lawrence, J.D.

    1993-11-01

    Planning the development, use and regulation of computer systems in nuclear reactor protection systems in such a way as to enhance reliability and safety is a complex issue. This report is one of a series of reports from the Computer Safety and Reliability Group, Lawrence Livermore that investigates different aspects of computer software in reactor National Laboratory, that investigates different aspects of computer software in reactor protection systems. There are two central themes in the report, First, software considerations cannot be fully understood in isolation from computer hardware and application considerations. Second, the process of engineering reliability and safety into a computer system requires activities to be carried out throughout the software life cycle. The report discusses the many activities that can be carried out during the software life cycle to improve the safety and reliability of the resulting product. The viewpoint is primarily that of the assessor, or auditor

  18. Software reliability and safety in nuclear reactor protection systems

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, J.D. [Lawrence Livermore National Lab., CA (United States)

    1993-11-01

    Planning the development, use and regulation of computer systems in nuclear reactor protection systems in such a way as to enhance reliability and safety is a complex issue. This report is one of a series of reports from the Computer Safety and Reliability Group, Lawrence Livermore that investigates different aspects of computer software in reactor National Laboratory, that investigates different aspects of computer software in reactor protection systems. There are two central themes in the report, First, software considerations cannot be fully understood in isolation from computer hardware and application considerations. Second, the process of engineering reliability and safety into a computer system requires activities to be carried out throughout the software life cycle. The report discusses the many activities that can be carried out during the software life cycle to improve the safety and reliability of the resulting product. The viewpoint is primarily that of the assessor, or auditor.

  19. Software development for a switch-based data acquisition system

    Energy Technology Data Exchange (ETDEWEB)

    Booth, A. (Superconducting Super Collider Lab., Dallas, TX (United States)); Black, D.; Walsh, D. (Fermi National Accelerator Lab., Batavia, IL (United States))

    1991-12-01

    We report on the software aspects of the development of a switch-based data acquisition system at Fermilab. This paper describes how, with the goal of providing an integrated systems engineering'' environment, several powerful software tools were put in place to facilitate extensive exploration of all aspects of the design. These tools include a simulation package, graphics package and an Expert System shell which have been integrated to provide an environment which encourages the close interaction of hardware and software engineers. This paper includes a description of the simulation, user interface, embedded software, remote procedure calls, and diagnostic software which together have enabled us to provide real-time control and monitoring of a working prototype switch-based data acquisition (DAQ) system.

  20. Hardware control system using modular software under RSX-11D

    International Nuclear Information System (INIS)

    Kittell, R.S.; Helland, J.A.

    1978-01-01

    A modular software system used to control extensive hardware is described. The development, operation, and experience with this software are discussed. Included are the methods employed to implement this system while taking advantage of the Real-Time features of RSX-11D. Comparisons are made between this system and an earlier nonmodular system. The controlled hardware includes magnet power supplies, stepping motors, DVM's, and multiplexors, and is interfaced through CAMAC. 4 figures

  1. Mussel-inspired immobilization of BN nanosheets onto poly(p-phenylene benzobisoxazole) fibers: Multifunctional interface for photothermal self-healing

    Science.gov (United States)

    Shao, Qing; Hu, Zhen; Xu, Xirong; Yu, Long; Zhang, Dayu; Huang, Yudong

    2018-05-01

    The composites with interfacial self-healing ability are smart and promising materials in the future. Although some approaches have been used to heal the micro-cracks in composite materials, it is still a great challenge to develop a versatile strategy to fabricate multifunctional interface for self-healing. Here, boron nitride nanosheets (BN) are immobilized onto PBO fibers by facile polydopamine (PDA) chemistry. Benefiting from the photothermal effect of BN-PDA, the obtained surface layer displays interfacial self-healing properties under Xenon light irradiation.

  2. Software System for Vocal Rendering of Printed Documents

    Directory of Open Access Journals (Sweden)

    Marian DARDALA

    2008-01-01

    Full Text Available The objective of this paper is to present a software system architecture developed to render the printed documents in a vocal form. On the other hand, in the paper are described the software solutions that exist as software components and are necessary for documents processing as well as for multimedia device controlling used by the system. The usefulness of this system is for people with visual disabilities that can access the contents of documents without that they be printed in Braille system or to exist in an audio form.

  3. A Configurable, Object-Oriented, Transportation System Software Framework

    Energy Technology Data Exchange (ETDEWEB)

    KELLY,SUZANNE M.; MYRE,JOHN W.; PRICE,MARK H.; RUSSELL,ERIC D.; SCOTT,DAN W.

    2000-08-01

    The Transportation Surety Center, 6300, has been conducting continuing research into and development of information systems for the Configurable Transportation Security and Information Management System (CTSS) project, an Object-Oriented Framework approach that uses Component-Based Software Development to facilitate rapid deployment of new systems while improving software cost containment, development reliability, compatibility, and extensibility. The direction has been to develop a Fleet Management System (FMS) framework using object-oriented technology. The goal for the current development is to provide a software and hardware environment that will demonstrate and support object-oriented development commonly in the FMS Central Command Center and Vehicle domains.

  4. The achievement and assessment of safety in systems containing software

    International Nuclear Information System (INIS)

    Ball, A.; Dale, C.J.; Butterfield, M.H.

    1986-01-01

    In order to establish confidence in the safe operation of a reactor protection system, there is a need to establish, as far as it is possible, that: (i) the algorithms used are correct; (ii) the system is a correct implementation of the algorithms; and (iii) the hardware is sufficiently reliable. This paper concentrates principally on the second of these, as it applies to the software aspect of the more accurate and complex trip functions to be performed by modern reactor protection systems. In order to engineer safety into software, there is a need to use a development strategy which will stand a high chance of achieving a correct implementation of the trip algorithms. This paper describes three broad methodologies by which it is possible to enhance the integrity of software: fault avoidance, fault tolerance and fault removal. Fault avoidance is concerned with making the software as fault free as possible by appropriate choice of specification, design and implementation methods. A fault tolerant strategy may be advisable in many safety critical applications, in order to guard against residual faults present in the software of the installed system. Fault detection and removal techniques are used to remove as many faults as possible of those introduced during software development. The paper also discusses safety and reliability assessment as it applies to software, outlining the various approaches available. Finally, there is an outline of a research project underway in the UKAEA which is intended to assess methods for developing and testing safety and protection systems involving software. (author)

  5. Availability of software services for a hospital information system.

    Science.gov (United States)

    Sakamoto, N

    1998-03-01

    Hospital information systems (HISs) are becoming more important and covering more parts in daily hospital operations as order-entry systems become popular and electronic charts are introduced. Thus, HISs today need to be able to provide necessary services for hospital operations for a 24-h day, 365 days a year. The provision of services discussed here does not simply mean the availability of computers, in which all that matters is that the computer is functioning. It means the provision of necessary information for hospital operations by the computer software, and we will call it the availability of software services. HISs these days are mostly client-server systems. To increase availability of software services in these systems, it is not enough to just use system structures that are highly reliable in existing host-centred systems. Four main components which support availability of software services are network systems, client computers, server computers, and application software. In this paper, we suggest how to structure these four components to provide the minimum requested software services even if a part of the system stops to function. The network system should be double-protected in stratus using Asynchronous Transfer Mode (ATM) as its base network. Client computers should be fat clients with as much application logic as possible, and reference information which do not require frequent updates (master files, for example) should be replicated in clients. It would be best if all server computers could be double-protected. However, if that is physically impossible, one database file should be made accessible by several server computers. Still, at least the basic patients' information and the latest clinical records should be double-protected physically. Application software should be tested carefully before introduction. Different versions of the application software should always be kept and managed in case the new version has problems. If a hospital

  6. The software product assurance metrics study: JPL's software systems quality and productivity

    Science.gov (United States)

    Bush, Marilyn W.

    1989-01-01

    The findings are reported of the Jet Propulsion Laboratory (JPL)/Software Product Assurance (SPA) Metrics Study, conducted as part of a larger JPL effort to improve software quality and productivity. Until recently, no comprehensive data had been assembled on how JPL manages and develops software-intensive systems. The first objective was to collect data on software development from as many projects and for as many years as possible. Results from five projects are discussed. These results reflect 15 years of JPL software development, representing over 100 data points (systems and subsystems), over a third of a billion dollars, over four million lines of code and 28,000 person months. Analysis of this data provides a benchmark for gauging the effectiveness of past, present and future software development work. In addition, the study is meant to encourage projects to record existing metrics data and to gather future data. The SPA long term goal is to integrate the collection of historical data and ongoing project data with future project estimations.

  7. Systems and software variability management concepts, tools and experiences

    CERN Document Server

    Capilla, Rafael; Kang, Kyo-Chul

    2013-01-01

    The success of product line engineering techniques in the last 15 years has popularized the use of software variability as a key modeling approach for describing the commonality and variability of systems at all stages of the software lifecycle. Software product lines enable a family of products to share a common core platform, while allowing for product specific functionality being built on top of the platform. Many companies have exploited the concept of software product lines to increase the resources that focus on highly differentiating functionality and thus improve their competitiveness

  8. The Software Bus, an Object-Oriented Data Exchange System

    International Nuclear Information System (INIS)

    Akerbaek, T.; Louka, M.

    1996-01-01

    This document describes the Software Bus System, developed for object-oriented task to task communication in a TCP/IP based network. The Software Bus is a set of library functions, developed to be used for the Picasso-3 UIMS, and as a general purpose tool for dynamically interfacing programs at run-time. The Software Bus offers a high level object-oriented data exchange mechanism that relieves the application programmer of the low level TCP/IP-programming and communication protocol handling. The Software Bus is currently available under several UNIX platforms and a version for Windows NT is planned for late 1996. (author)

  9. Simulation-Aided Design of Tubular Polymeric Capsules for Self-Healing Concrete

    Science.gov (United States)

    Šavija, Branko; Feiteira, João; Araújo, Maria; Chatrabhuti, Sutima; Raquez, Jean-Marie; Van Tittelboom, Kim; Gruyaert, Elke; De Belie, Nele; Schlangen, Erik

    2016-01-01

    Polymeric capsules can have an advantage over glass capsules used up to now as proof-of-concept carriers in self-healing concrete. They allow easier processing and afford the possibility to fine tune their mechanical properties. Out of the multiple requirements for capsules used in this context, the capability of rupturing when crossed by a crack in concrete of a typical size is one of the most relevant, as without it no healing agent is released into the crack. This study assessed the fitness of five types of polymeric capsules to fulfill this requirement by using a numerical model to screen the best performing ones and verifying their fitness with experimental methods. Capsules made of a specific type of poly(methyl methacrylate) (PMMA) were considered fit for the intended application, rupturing at average crack sizes of 69 and 128 μm, respectively for a wall thickness of ~0.3 and ~0.7 mm. Thicker walls were considered unfit, as they ruptured for crack sizes much higher than 100 μm. Other types of PMMA used and polylactic acid were equally unfit for the same reason. There was overall good fitting between model output and experimental results and an elongation at break of 1.5% is recommended regarding polymers for this application. PMID:28772370

  10. Current challenges and future directions for bacterial self-healing concrete.

    Science.gov (United States)

    Lee, Yun Suk; Park, Woojun

    2018-04-01

    Microbially induced calcium carbonate precipitation (MICP) has been widely explored and applied in the field of environmental engineering over the last decade. Calcium carbonate is naturally precipitated as a byproduct of various microbial metabolic activities. This biological process was brought into practical use to restore construction materials, strengthen and remediate soil, and sequester carbon. MICP has also been extensively examined for applications in self-healing concrete. Biogenic crack repair helps mitigate the high maintenance costs of concrete in an eco-friendly manner. In this process, calcium carbonate precipitation (CCP)-capable bacteria and nutrients are embedded inside the concrete. These bacteria are expected to increase the durability of the concrete by precipitating calcium carbonate in situ to heal cracks that develop in the concrete. However, several challenges exist with respect to embedding such bacteria; harsh conditions in concrete matrices are unsuitable for bacterial life, including high alkalinity (pH up to 13), high temperatures during manufacturing processes, and limited oxygen supply. Additionally, many biological factors, including the optimum conditions for MICP, the molecular mechanisms involved in MICP, the specific microorganisms suitable for application in concrete, the survival characteristics of the microorganisms embedded in concrete, and the amount of MICP in concrete, remain unclear. In this paper, metabolic pathways that result in conditions favorable for calcium carbonate precipitation, current and potential applications in concrete, and the remaining biological challenges are reviewed.

  11. Nanocontainer-Enhanced Self-Healing for Corrosion-Resistant Ni Coating on Mg Alloy.

    Science.gov (United States)

    Xie, Zhi-Hui; Li, Dan; Skeete, Zakiya; Sharma, Anju; Zhong, Chuan-Jian

    2017-10-18

    The ability to manipulate the functionalization of Ni coating is of great importance in improving the corrosion resistance of magnesium (Mg) alloy for many industrial applications. In the present work, MCM-41 type mesoporous silica nanocontainers (MSNs) loaded with corrosion inhibitor (NaF) were synthesized and employed as smart reinforcements to enhance the integrity and corrosion inhibition of the Ni coating. The incorporation of the F-loaded MSNs (F@MSNs) to enhance the corrosion resistant capacity of a metallic coating is reported for the first time. The mesoporous structures of the as-prepared MSNs and F@MSNs were confirmed by transmission electron microscopy (TEM), small angle X-rays scattering (SAXS), and N 2 adsorption-desorption isotherms. The X-ray photoelectron spectroscopy (XPS) data demonstrated the successful immobilization of fluoride ion on the MSNs and formation of a magnesium fluoride (MgF 2 ) protective film at the corrosion sites of the Mg alloy upon soaking in a F@MSNs-containing NaCl solution. The results from potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) for both bare Mg alloy and Ni coatings with and without F@MSNs have revealed a clear decrease in corrosion rate in a corrosive solution for a long-time immersion due to the introduction of F@MSNs. These findings open new opportunities in the exploration of self-healing metallic coatings for highly enhanced anticorrosion protection of Mg alloy.

  12. Bioinspired Ultratough Hydrogel with Fast Recovery, Self-Healing, Injectability and Cytocompatibility.

    Science.gov (United States)

    Azevedo, Sara; Costa, Ana M S; Andersen, Amanda; Choi, Insung S; Birkedal, Henrik; Mano, João F

    2017-07-01

    Inspired by the mussel byssus adhesiveness, a highly hydrated polymeric structure is designed to combine, for the first time, a set of interesting features for load-bearing purposes. These characteristics include: i) a compressive strength and stiffness in the MPa range, ii) toughness and the ability to recover it upon successive cyclic loading, iii) the ability to quickly self-heal upon rupture, iv) the possibility of administration through minimally invasive techniques, such as by injection, v) the swelling ratio being adjusted to space-filling applications, and vi) cytocompatibility. Owing to these characteristics and the mild conditions employed, the encapsulation of very unstable and sensitive cargoes is possible, highlighting their potential to researchers in the biomedical field for the repair of load-bearing soft tissues, or to be used as an encapsulation platform for a variety of biological applications such as disease models for drug screening and therapies in a more realistic mechanical environment. Moreover, given the simplicity of this methodology and the enhanced mechanical performance, this strategy can be expanded to applications in other fields, such as agriculture and electronics. As such, it is anticipated that the proposed strategy will constitute a new, versatile, and cost-effective tool to produce engineered polymeric structures for both science and technology. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Piezoelectric and mechanical properties of fatigue resistant, self-healing PZT–ionomer composites

    International Nuclear Information System (INIS)

    James, N K; Lafont, U; Van der Zwaag, S; Groen, W A

    2014-01-01

    Piezoelectric ceramic–polymer composites with 0–3 connectivity were fabricated using lead zirconium titanate (PZT) powder dispersed in an ionomer (Zn ionomer) and its reference ethylene methacrylic acid copolymer (EMAA) polymer matrix. The PZT–Zn ionomer and PZT–EMAA composites were prepared by melt extrusion followed by hot pressing. The effects of poling conditions such as temperature, time and electric field on the piezoelectric properties of the composites were investigated. The experimentally observed piezoelectric charge coefficient and dielectric constant of the composites were compared with theoretical models. The results show that PZT–Zn ionomer composites have better piezoelectric properties compared to PZT–EMAA composites. The static and fatigue properties of the composites were investigated. The PZT–Zn ionomer composites were found to have excellent fatigue resistance even at strain levels of 4%. Due to the self-healing capabilities of the ionomer matrix, the loss of piezoelectric properties after high strain tensile cyclic loading could be partially recovered by thermal healing. (paper)

  14. Piezoelectric and mechanical properties of fatigue resistant, self-healing PZT-ionomer composites

    Science.gov (United States)

    James, N. K.; Lafont, U.; van der Zwaag, S.; Groen, W. A.

    2014-05-01

    Piezoelectric ceramic-polymer composites with 0-3 connectivity were fabricated using lead zirconium titanate (PZT) powder dispersed in an ionomer (Zn ionomer) and its reference ethylene methacrylic acid copolymer (EMAA) polymer matrix. The PZT-Zn ionomer and PZT-EMAA composites were prepared by melt extrusion followed by hot pressing. The effects of poling conditions such as temperature, time and electric field on the piezoelectric properties of the composites were investigated. The experimentally observed piezoelectric charge coefficient and dielectric constant of the composites were compared with theoretical models. The results show that PZT-Zn ionomer composites have better piezoelectric properties compared to PZT-EMAA composites. The static and fatigue properties of the composites were investigated. The PZT-Zn ionomer composites were found to have excellent fatigue resistance even at strain levels of 4%. Due to the self-healing capabilities of the ionomer matrix, the loss of piezoelectric properties after high strain tensile cyclic loading could be partially recovered by thermal healing.

  15. Whiskers growth and self-healing in Ti-based metallic glasses during ion irradiation

    Science.gov (United States)

    Zhang, Kun; Hu, Zheng; Zhao, Ziqiang; Wei, Bingchen; Li, Yansen; Wei, Yuhang

    2018-04-01

    Ti-based metallic glasses were subjected to a 20 MeV Cl4+ ion radiation under liquid-nitrogen cooling. Their responses, as well as effects of the electronic excitation and nucleus-nucleus collision were evaluated. The collision cascade during irradiation typically changes the structure by increasing the liquid-like zone/cluster, or the content of the free volume. However, along the ion incident depth, the structure change is inhomogeneous. Numerous whiskers appear and aggregate on the side of the irradiation surface, which are several micrometers away from the edge. This corresponds with the maximum collision depth obtained by the Monte Carlo simulation, where nuclear loss plays a dominant role. Moreover, the liquid-like zone continually forms, which add to the whiskers growth and subsequent self-healing. Results suggest that the irradiation-induced local shear stress combines with the well-localized liquid-like zone results in the observed phenomena. This study demonstrates that metallic glasses have high morphological instability under ion irradiation, which assets can pave new paths for their further applications.

  16. Self-Healing Characteristics of Damaged Rock Salt under Different Healing Conditions

    Directory of Open Access Journals (Sweden)

    Lin Li

    2013-08-01

    Full Text Available Salt deposits are commonly regarded as ideal hosts for geologic energy reservoirs. Underground cavern construction-induced damage in salt is reduced by self-healing. Thus, studying the influencing factors on such healing processes is important. This research uses ultrasonic technology to monitor the longitudinal wave velocity variations of stress-damaged rock salts during self-recovery experiments under different recovery conditions. The influences of stress-induced initial damage, temperature, humidity, and oil on the self-recovery of damaged rock salts are analyzed. The wave velocity values of the damaged rock salts increase rapidly during the first 200 h of recovery, and the values gradually increase toward stabilization after 600 h. The recovery of damaged rock salts is subjected to higher initial damage stress. Water is important in damage recovery. The increase in temperature improves damage recovery when water is abundant, but hinders recovery when water evaporates. The presence of residual hydraulic oil blocks the inter-granular role of water and restrains the recovery under triaxial compression. The results indicate that rock salt damage recovery is related to the damage degree, pore pressure, temperature, humidity, and presence of oil due to the sealing integrity of the jacket material.

  17. Polyampholyte hydrogel electrolytes for flexible and self-healing aqueous supercapacitor for low temperature applications

    Science.gov (United States)

    Chung, Hyun-Joong; Li, Xinda

    Quenched polyampholytes provide a novel class of tough hydrogel that has self-healing ability, strong adhesion, and mechanical flexibility. In this study, we show that the polyampholyte hydrogels can be utilized as an aqueous gel electrolyte material that is especially useful for low temperature operations; at -30 °C, energy density of 10.5 Wh/kg at a power density of 500 W/kg was achieved. The high performance at the low temperature is associated to the concept of non-freezable water near the hydrophilic polymer chains. A comparison between differential scanning calorimetry (DSC) measurements for polyampholytes that contained KOH and neat KOH solution revealed that increased amount of water molecules become non-freezable when the solution is contained in the hydrogel networks. In addition, the crosslinked network structure of the polyampholyte chains disrupts the crystalline growth of ice, resulting in `slush-like' ice formation. The interplay between the increased amount of unfrozen water and the limited growth of ice crystals leads to the enhanced supercapacitor performance at low temperatures.

  18. Microencapsulation of 2-octylcyanoacrylate tissue adhesive for self-healing acrylic bone cement.

    Science.gov (United States)

    Brochu, Alice B W; Chyan, William J; Reichert, William M

    2012-10-01

    Here, we report the first phase of developing self-healing acrylic bone cement: the preparation and characterization of polyurethane (PUR) microcapsules containing a medical cyanoacrylate tissue adhesive. Capsules were prepared by interfacial polymerization of a toluene-2,4-diisocyanate-based polyurethane prepolymer with 1,4-butanediol to encapsulate 2-octylcyanoacrylate (OCA). Various capsule characteristics, including: resultant morphology, average size and size distribution, shell thickness, content and reactivity of encapsulated agent, and shelf life are investigated and their reliance on solvent type and amount, surfactant type and amount, temperature, pH, agitation rate, reaction time, and mode of addition of the oil phase to the aqueous phase are presented. Capsules had average diameters ranging from 74 to 222 μm and average shell thicknesses ranging from 1.5 to 6 μm. The capsule content was determined via thermogravimetric analysis and subsequent analysis of the capsules following up to 8 weeks storage revealed minimal loss of core contents. Mechanical testing of OCA-containing capsules showed individual capsules withstood compressive forces up to a few tenths of Newtons, and the contents released from crushed capsules generated tensile adhesive forces of a few Newtons. Capsules were successfully mixed into the poly(methyl methacrylate) bone cement, surviving the mixing process, exposure to methyl methacrylate monomer, and the resulting exothermic matrix curing. Copyright © 2012 Wiley Periodicals, Inc.

  19. Formation and 'self-healing' of magnetic islands in finite-β Helias equilibria

    International Nuclear Information System (INIS)

    Hayashi, T.; Sato, T.; Merkel, P.; Nuehrenberg, J.; Schwenn, U.

    1994-01-01

    The behaviour of finite-pressure-induced magnetic islands is numerically analyzed for three-dimensional magnetohydrodynamic equilibria of the Helias configuration by using a three-dimensional equilibrium code. It is found that an island chain is generated on the 5/6 rational surface, when such a surface appears in the plasma region of the finite-β equilibrium. The island chain, however, is not so dangerous as to destroy the plasma confinement even if it appears in a vanishingly small shear region. Thus, a high β equilibrium with clear magnetic surfaces can be realized. Moreover, it is definitely confirmed that the finite pressure effect sometimes exhibits an unexpectedly good aspect, namely, that the vacuum islands are removed as β increases, which can be called 'self-healing' of islands. This property can be explained by the numerically discovered fact that the phases of islands induced by the finite-pressure effect are always locked in the same phase regardless of β. (author)

  20. A computational model for the flow of resin in self-healing composites

    Science.gov (United States)

    Hall, J.; Qamar, I. P. S.; Rendall, T. C. S.; Trask, R. S.

    2015-03-01

    To explore the flow characteristics of healing agent leaving a vascular network and infusing a damage site within a fibre reinforced polymer composite, a numerical model of healing agent flow from an orifice has been developed using smoothed particle hydrodynamics. As an initial validation the discharge coefficient for low Reynolds number flow from a cylindrical tank is calculated numerically, using two different viscosity formulations, and compared to existing experimental data. Results of this comparison are very favourable; the model is able to reproduce experimental results for the discharge coefficient in the high Reynolds number limit, together with the power-law behaviour for low Reynolds numbers. Results are also presented for a representative delamination geometry showing healing fluid behaviour and fraction filled inside the delamination for a variety of fluid viscosities. This work provides the foundations for the vascular self-healing community in calculating not only the flow rate through the network, but also, by simulating a representative damage site, the final location of the healing fluid within the damage site in order to assess the improvement in local and global mechanical properties and thus healing efficiency.

  1. A system for automatic evaluation of simulation software

    Science.gov (United States)

    Ryan, J. P.; Hodges, B. C.

    1976-01-01

    Within the field of computer software, simulation and verification are complementary processes. Simulation methods can be used to verify software by performing variable range analysis. More general verification procedures, such as those described in this paper, can be implicitly, viewed as attempts at modeling the end-product software. From software requirement methodology, each component of the verification system has some element of simulation to it. Conversely, general verification procedures can be used to analyze simulation software. A dynamic analyzer is described which can be used to obtain properly scaled variables for an analog simulation, which is first digitally simulated. In a similar way, it is thought that the other system components and indeed the whole system itself have the potential of being effectively used in a simulation environment.

  2. A Reusable Software Architecture for Small Satellite AOCS Systems

    DEFF Research Database (Denmark)

    Alminde, Lars; Bendtsen, Jan Dimon; Laursen, Karl Kaas

    2006-01-01

    This paper concerns the software architecture called Sophy, which is an abbreviation for Simulation, Observation, and Planning in HYbrid systems. We present a framework that allows execution of hybrid dynamical systems in an on-line distributed computing environment, which includes interaction...... with both hardware and on-board software. Some of the key issues addressed by the framework are automatic translation of mathematical specifications of hybrid systems into executable software entities, management of execution of coupled models in a parallel distributed environment, as well as interaction...... with external components, hardware and/or software, through generic interfaces. Sophy is primarily intended as a tool for development of model based reusable software for the control and autonomous functions of satellites and/or satellite clusters....

  3. Software Engineering Issues for Cyber-Physical Systems

    DEFF Research Database (Denmark)

    Al-Jaroodi, Jameela; Mohamed, Nader; Jawhar, Imad

    2016-01-01

    step; however, designing and implementing the right software to integrate and use them effectively is essential. The software facilitates better interfaces, more control and adds smart services, high flexibility and many other added values and features to the CPS. However, software development for CPS......Cyber-Physical Systems (CPS) provide many smart features for enhancing physical processes. These systems are designed with a set of distributed hardware, software, and network components that are embedded in physical systems and environments or attached to humans. Together they function seamlessly...... to offer specific functionalities or features that help enhance human lives, operations or environments. While different CPS components play important roles in a successful CPS development, the software plays the most important role among them. Acquiring and using high quality CPS components is the first...

  4. Testing methodology of embedded software in digital plant protection system

    International Nuclear Information System (INIS)

    Seong, Ah Young; Choi, Bong Joo; Lee, Na Young; Hwang, Il Soon

    2001-01-01

    It is necessary to assure the reliability of software in order to digitalize RPS(Reactor Protection System). Since RPS causes fatal damage on accidental cases, it is classified as Safety 1E class. Therefore we propose the effective testing methodology to assure the reliability of embedded software in the DPPS(Digital Plant Protection System). To test the embedded software effectively in DPPS, our methodology consists of two steps. The first is the re-engineering step that extracts classes from structural source program, and the second is the level of testing step which is composed of unit testing, Integration Testing and System Testing. On each testing step we test the embedded software with selected test cases after the test item identification step. If we use this testing methodology, we can test the embedded software effectively by reducing the cost and the time

  5. 78 FR 47011 - Software Unit Testing for Digital Computer Software Used in Safety Systems of Nuclear Power Plants

    Science.gov (United States)

    2013-08-02

    ... NUCLEAR REGULATORY COMMISSION [NRC-2012-0195] Software Unit Testing for Digital Computer Software... revised regulatory guide (RG), revision 1 of RG 1.171, ``Software Unit Testing for Digital Computer Software Used in Safety Systems of Nuclear Power Plants.'' This RG endorses American National Standards...

  6. 77 FR 50722 - Software Unit Testing for Digital Computer Software Used in Safety Systems of Nuclear Power Plants

    Science.gov (United States)

    2012-08-22

    ... NUCLEAR REGULATORY COMMISSION [NRC-2012-0195] Software Unit Testing for Digital Computer Software...) is issuing for public comment draft regulatory guide (DG), DG-1208, ``Software Unit Testing for Digital Computer Software used in Safety Systems of Nuclear Power Plants.'' The DG-1208 is proposed...

  7. SOFTM: a software maintenance expert system in Prolog

    DEFF Research Database (Denmark)

    Pau, L.; Negret, J. M.

    1988-01-01

    A description is given of a knowledge-based system called SOFTM, serving the following purposes: (1) assisting a software programmer or analyst in his application code maintenance tasks, (2) generating and updating automatically software correction documentation, (3) helping the end user register......, and on interfacing capabilities of Prolog II to a variety of other languages...

  8. Integrated analysis software for bulk power system stability

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T; Nagao, T; Takahashi, K [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

    1994-12-31

    This paper presents Central Research Inst.of Electric Power Industry - CRIEPI`s - own developed three softwares for bulk power network analysis and the user support system which arranges tremendous data necessary for these softwares with easy and high reliability. (author) 3 refs., 7 figs., 2 tabs.

  9. Software for ASS-500 based early warning system

    International Nuclear Information System (INIS)

    Lipinski, P.; Isajenko, K.

    1998-01-01

    The article describes the software for the management of early warning system based on ASS-500 station. The software can communicate with the central computer using TCP/IP protocol. This allows remote control of the station through modem or local area network connection. The article describes Windows based user interface of the program

  10. Conceptual design for controller software of mechatronic systems

    NARCIS (Netherlands)

    Broenink, Johannes F.; Hilderink, G.H.; Bakkers, André; Bradshaw, Alan; Counsell, John

    1998-01-01

    The method and software tool presented here, aims at supporting the development of control software for mechatronic systems. Heterogeneous distributed embedded processors are considered as target hardware. Principles of the method are that the implementation process is a stepwise refinement from

  11. Automated transportation management system (ATMS) software project management plan (SPMP)

    Energy Technology Data Exchange (ETDEWEB)

    Weidert, R.S., Westinghouse Hanford

    1996-05-20

    The Automated Transportation Management System (ATMS) Software Project Management plan (SPMP) is the lead planning document governing the life cycle of the ATMS and its integration into the Transportation Information Network (TIN). This SPMP defines the project tasks, deliverables, and high level schedules involved in developing the client/server ATMS software.

  12. Temperature Scanning Stress Relaxation of an Autonomous Self-Healing Elastomer Containing Non-Covalent Reversible Network Junctions

    Directory of Open Access Journals (Sweden)

    Amit Das

    2018-01-01

    Full Text Available In this work, we report about the mechanical relaxation characteristics of an intrinsically self-healable imidazole modified commercial rubber. This kind of self-healing rubber was prepared by melt mixing of 1-butyl imidazole with bromo-butyl rubber (bromine modified isoprene-isobutylene copolymer, BIIR. By this melt mixing process, the reactive allylic bromine of bromo-butyl rubber was converted into imidazole bromide salt. The resulting development of an ionic character to the polymer backbone leads to an ionic association of the groups which ultimately results to the formation of a network structure of the rubber chains. The modified BIIR thus behaves like a robust crosslinked rubber and shows unusual self-healing properties. The non-covalent reversible network has been studied in detail with respect to stress relaxation experiments, scanning electron microscopic and X-ray scattering.

  13. Mechanical Characterization of High-Performance Steel-Fiber Reinforced Cement Composites with Self-Healing Effect

    Science.gov (United States)

    Kim, Dong Joo; Kang, Seok Hee; Ahn, Tae-Ho

    2014-01-01

    The crack self-healing behavior of high-performance steel-fiber reinforced cement composites (HPSFRCs) was investigated. High-strength deformed steel fibers were employed in a high strength mortar with very fine silica sand to decreasing the crack width by generating higher interfacial bond strength. The width of micro-cracks, strongly affected by the type of fiber and sand, clearly produced the effects on the self-healing behavior. The use of fine silica sand in HPSFRCs with high strength deformed steel fibers successfully led to rapid healing owing to very fine cracks with width less than 20 μm. The use of very fine silica sand instead of normal sand produced 17%–19% higher tensile strength and 51%–58% smaller width of micro-cracks. PMID:28788471

  14. A Social Potential Fields Approach for Self-Deployment and Self-Healing in Hierarchical Mobile Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Eva González-Parada

    2017-01-01

    Full Text Available Autonomous mobile nodes in mobile wireless sensor networks (MWSN allow self-deployment and self-healing. In both cases, the goals are: (i to achieve adequate coverage; and (ii to extend network life. In dynamic environments, nodes may use reactive algorithms so that each node locally decides when and where to move. This paper presents a behavior-based deployment and self-healing algorithm based on the social potential fields algorithm. In the proposed algorithm, nodes are attached to low cost robots to autonomously navigate in the coverage area. The proposed algorithm has been tested in environments with and without obstacles. Our study also analyzes the differences between non-hierarchical and hierarchical routing configurations in terms of network life and coverage.

  15. A Social Potential Fields Approach for Self-Deployment and Self-Healing in Hierarchical Mobile Wireless Sensor Networks.

    Science.gov (United States)

    González-Parada, Eva; Cano-García, Jose; Aguilera, Francisco; Sandoval, Francisco; Urdiales, Cristina

    2017-01-09

    Autonomous mobile nodes in mobile wireless sensor networks (MWSN) allow self-deployment and self-healing. In both cases, the goals are: (i) to achieve adequate coverage; and (ii) to extend network life. In dynamic environments, nodes may use reactive algorithms so that each node locally decides when and where to move. This paper presents a behavior-based deployment and self-healing algorithm based on the social potential fields algorithm. In the proposed algorithm, nodes are attached to low cost robots to autonomously navigate in the coverage area. The proposed algorithm has been tested in environments with and without obstacles. Our study also analyzes the differences between non-hierarchical and hierarchical routing configurations in terms of network life and coverage.

  16. An autonomously electrically self-healing liquid metal-elastomer composite for robust soft-matter robotics and electronics.

    Science.gov (United States)

    Markvicka, Eric J; Bartlett, Michael D; Huang, Xiaonan; Majidi, Carmel

    2018-07-01

    Large-area stretchable electronics are critical for progress in wearable computing, soft robotics and inflatable structures. Recent efforts have focused on engineering electronics from soft materials-elastomers, polyelectrolyte gels and liquid metal. While these materials enable elastic compliance and deformability, they are vulnerable to tearing, puncture and other mechanical damage modes that cause electrical failure. Here, we introduce a material architecture for soft and highly deformable circuit interconnects that are electromechanically stable under typical loading conditions, while exhibiting uncompromising resilience to mechanical damage. The material is composed of liquid metal droplets suspended in a soft elastomer; when damaged, the droplets rupture to form new connections with neighbours and re-route electrical signals without interruption. Since self-healing occurs spontaneously, these materials do not require manual repair or external heat. We demonstrate this unprecedented electronic robustness in a self-repairing digital counter and self-healing soft robotic quadruped that continue to function after significant damage.

  17. Software architecture considerations for ion source control systems

    International Nuclear Information System (INIS)

    Sinclair, J.W.

    1997-09-01

    General characteristics of distributed control system software tools are examined from the perspective of ion source control system requirements. Emphasis is placed on strategies for building extensible, distributed systems in which the ion source element is one component of a larger system. Vsystem, a commercial software tool kit from Vista Control Systems was utilized extensively in the control system upgrade of the Holifield Radioactive Ion Beam Facility. Part of the control system is described and the characteristics of Vsystem are examined and compared with those of EPICS, the Experimental Physics and Industrial Control System

  18. Prototype Software for Automated Structural Analysis of Systems

    DEFF Research Database (Denmark)

    Jørgensen, A.; Izadi-Zamanabadi, Roozbeh; Kristensen, M.

    2004-01-01

    In this paper we present a prototype software tool that is developed to analyse the structural model of automated systems in order to identify redundant information that is hence utilized for Fault detection and Isolation (FDI) purposes. The dedicated algorithms in this software tool use a tri......-partite graph that represents the structural model of the system. A component-based approach has been used to address issues such as system complexity and recon¯gurability possibilities....

  19. Prototype Software for Automated Structural Analysis of Systems

    DEFF Research Database (Denmark)

    Jørgensen, A.; Izadi-Zamanabadi, Roozbeh; Kristensen, M.

    2004-01-01

    In this paper we present a prototype software tool that is developed to analyse the structural model of automated systems in order to identify redundant information that is hence utilized for Fault detection and Isolation (FDI) purposes. The dedicated algorithms in this software tool use a tri......-partite graph that represents the structural model of the system. A component-based approach has been used to address issues such as system complexity and reconfigurability possibilities....

  20. Capturing security requirements for software systems.

    Science.gov (United States)

    El-Hadary, Hassan; El-Kassas, Sherif

    2014-07-01

    Security is often an afterthought during software development. Realizing security early, especially in the requirement phase, is important so that security problems can be tackled early enough before going further in the process and avoid rework. A more effective approach for security requirement engineering is needed to provide a more systematic way for eliciting adequate security requirements. This paper proposes a methodology for security requirement elicitation based on problem frames. The methodology aims at early integration of security with software development. The main goal of the methodology is to assist developers elicit adequate security requirements in a more systematic way during the requirement engineering process. A security catalog, based on the problem frames, is constructed in order to help identifying security requirements with the aid of previous security knowledge. Abuse frames are used to model threats while security problem frames are used to model security requirements. We have made use of evaluation criteria to evaluate the resulting security requirements concentrating on conflicts identification among requirements. We have shown that more complete security requirements can be elicited by such methodology in addition to the assistance offered to developers to elicit security requirements in a more systematic way.

  1. Capturing security requirements for software systems

    Directory of Open Access Journals (Sweden)

    Hassan El-Hadary

    2014-07-01

    Full Text Available Security is often an afterthought during software development. Realizing security early, especially in the requirement phase, is important so that security problems can be tackled early enough before going further in the process and avoid rework. A more effective approach for security requirement engineering is needed to provide a more systematic way for eliciting adequate security requirements. This paper proposes a methodology for security requirement elicitation based on problem frames. The methodology aims at early integration of security with software development. The main goal of the methodology is to assist developers elicit adequate security requirements in a more systematic way during the requirement engineering process. A security catalog, based on the problem frames, is constructed in order to help identifying security requirements with the aid of previous security knowledge. Abuse frames are used to model threats while security problem frames are used to model security requirements. We have made use of evaluation criteria to evaluate the resulting security requirements concentrating on conflicts identification among requirements. We have shown that more complete security requirements can be elicited by such methodology in addition to the assistance offered to developers to elicit security requirements in a more systematic way.

  2. Spaceport Command and Control System Software Development

    Science.gov (United States)

    Mahlin, Jonathan Nicholas

    2017-01-01

    There is an immense challenge in organizing personnel across a large agency such as NASA, or even over a subset of that, like a center's Engineering directorate. Workforce inefficiencies and challenges are bound to grow over time without oversight and management. It is also not always possible to hire new employees to fill workforce gaps, therefore available resources must be utilized more efficiently. The goal of this internship was to develop software that improves organizational efficiency by aiding managers, making employee information viewable and editable in an intuitive manner. This semester I created an application for managers that aids in optimizing allocation of employee resources for a single division with the possibility of scaling upwards. My duties this semester consisted of developing frontend and backend software to complete this task. The application provides user-friendly information displays and documentation of the workforce to allow NASA to track diligently track the status and skills of its workforce. This tool should be able to prove that current employees are being effectively utilized and if new hires are necessary to fulfill skill gaps.

  3. Capturing security requirements for software systems

    Science.gov (United States)

    El-Hadary, Hassan; El-Kassas, Sherif

    2014-01-01

    Security is often an afterthought during software development. Realizing security early, especially in the requirement phase, is important so that security problems can be tackled early enough before going further in the process and avoid rework. A more effective approach for security requirement engineering is needed to provide a more systematic way for eliciting adequate security requirements. This paper proposes a methodology for security requirement elicitation based on problem frames. The methodology aims at early integration of security with software development. The main goal of the methodology is to assist developers elicit adequate security requirements in a more systematic way during the requirement engineering process. A security catalog, based on the problem frames, is constructed in order to help identifying security requirements with the aid of previous security knowledge. Abuse frames are used to model threats while security problem frames are used to model security requirements. We have made use of evaluation criteria to evaluate the resulting security requirements concentrating on conflicts identification among requirements. We have shown that more complete security requirements can be elicited by such methodology in addition to the assistance offered to developers to elicit security requirements in a more systematic way. PMID:25685514

  4. Traceability of Software Safety Requirements in Legacy Safety Critical Systems

    Science.gov (United States)

    Hill, Janice L.

    2007-01-01

    How can traceability of software safety requirements be created for legacy safety critical systems? Requirements in safety standards are imposed most times during contract negotiations. On the other hand, there are instances where safety standards are levied on legacy safety critical systems, some of which may be considered for reuse for new applications. Safety standards often specify that software development documentation include process-oriented and technical safety requirements, and also require that system and software safety analyses are performed supporting technical safety requirements implementation. So what can be done if the requisite documents for establishing and maintaining safety requirements traceability are not available?

  5. Using Software Architectures for Designing Distributed Embedded Systems

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak

    In this paper, we outline an on-going project of designing distributed embedded systems for closed-loop process control. The project is a joint effort between software architecture researchers and developers from two companies that produce commercial embedded process control systems. The project...... has a strong emphasis on software architectural issues and terminology in order to envision, design and analyze design alternatives. We present two results. First, we outline how focusing on software architecture, architectural issues and qualities are beneficial in designing distributed, embedded......, systems. Second, we present two different architectures for closed-loop process control and discuss benefits and reliabilities....

  6. Amine-modified magnetic iron oxide nanoparticle as a promising carrier for application in bio self-healing concrete.

    Science.gov (United States)

    Seifan, Mostafa; Ebrahiminezhad, Alireza; Ghasemi, Younes; Samani, Ali Khajeh; Berenjian, Aydin

    2018-01-01

    Self-healing mechanisms are a promising solution to address the concrete cracking issue. Among the investigated self-healing strategies, the biotechnological approach is distinguished itself by inducing the most compatible material with concrete composition. In this method, the potent bacteria and nutrients are incorporated into the concrete matrix. Once cracking occurs, the bacteria will be activated, and the induced CaCO 3 crystals will seal the concrete cracks. However, the effectiveness of a bio self-healing concrete strictly depends on the viability of bacteria. Therefore, it is required to protect the bacteria from the resulted shear forces caused by mixing and drying shrinkage of concrete. Due to the positive effects on mechanical properties and the high compatibility of metallic nanoparticles with concrete composition, for the first time, we propose 3-aminopropyltriethoxy silane-coated iron oxide nanoparticles (APTES-coated IONs) as a biocompatible carrier for Bacillus species. This study was aimed to investigate the effect of APTES-coated IONs on the bacterial viability and CaCO 3 yield for future application in the concrete structures. The APTES-coated IONs were successfully synthesized and characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results show that the presence of 100 μg/mL APTES-coated IONs could increase the bacterial viability. It was also found that the CaCO 3 -specific yield was significantly affected in the presence of APTES-coated IONs. The highest CaCO 3 -specific yield was achieved when the cells were decorated with 50 μg/mL of APTES-coated IONs. This study provides new insights for the application of APTES-coated IONs in designing bio self-healing strategies.

  7. A parametric study on hydraulic conductivity and self-healing properties of geotextile clay liners used in landfills.

    Science.gov (United States)

    Parastar, Fatemeh; Hejazi, Sayyed Mahdi; Sheikhzadeh, Mohammad; Alirezazadeh, Azam

    2017-11-01

    Nowadays, the raise of excessive generation of solid wastes is considered as a major environmental concern due to the fast global population growth. The contamination of groundwater from landfill leachate compromises every living creature. Geotextile clay liner (GCL) that has a sandwich structure with two fibrous sheets and a clay core can be considered as an engineered solution to prevent hazardous pollutants from entering into groundwater. The main objective of the present study is therefore to enhance the performance of GCL structures. By changing some structural factors such as clay type (sodium vs. calcium bentonite), areal density of clay, density of geotextile, geotextile thickness, texture type (woven vs. nonwoven), and needle punching density a series of GCL samples were fabricated. Water pressure, type of cover soil and overburden pressure were the environmental variables, while the response variables were hydraulic conductivity and self-healing rate of GCL. Rigid wall constant head permeability test was conducted on all the samples. The outlet water flow was measured and evaluated at a defined time period and the hydraulic conductivity was determined for each sample. In the final stage, self-healing properties of samples were investigated and an analytical model was used to explain the results. It was found that higher Montmorillonite content of clay, overburden pressure, needle punching density and areal density of clay poses better self-healing properties and less hydraulic conductivity, meanwhile, an increase in water pressure increases the hydraulic conductivity. Moreover, the observations were aligned with the analytical model and indicated that higher fiber inclusion as a result of higher needle-punching density produces closer contact between bentonite and fibers, reduces hydraulic conductivity and increases self-healing properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Novel antifouling self-healing poly(carboxybetaine methacrylamide-co-HEMA) nanocomposite hydrogels with superior mechanical properties

    Czech Academy of Sciences Publication Activity Database

    Kostina, Nina Yu.; Sharifi, S.; de los Santos Pereira, Andres; Michálek, Jiří; Grijpma, D. W.; Rodriguez-Emmenegger, Cesar

    2013-01-01

    Roč. 1, č. 41 (2013), s. 5644-5650 ISSN 2050-750X R&D Projects: GA AV ČR KAN200520804; GA ČR GA13-00939S; GA ČR GAP205/12/1702; GA ČR GAP106/12/1451; GA ČR GBP205/12/G118 Institutional support: RVO:61389013 Keywords : hydrogels * self- healing * antifouling Subject RIV: CD - Macromolecular Chemistry

  9. Multiple self-healing squamous epithelioma is caused by a disease-specific spectrum of mutations in TGFBR1

    DEFF Research Database (Denmark)

    Goudie, David R; D'Alessandro, Mariella; Merriman, Barry

    2011-01-01

    Multiple self-healing squamous epithelioma (MSSE), also known as Ferguson-Smith disease (FSD), is an autosomal-dominant skin cancer condition characterized by multiple squamous-carcinoma-like locally invasive skin tumors that grow rapidly for a few weeks before spontaneously regressing, leaving......-of-function TGFBR1 mutations and MSSE. This distinguishes MSSE from the Marfan syndrome-related disorders in which missense mutations in TGFBR1 lead to developmental defects with vascular involvement but no reported predisposition to cancer....

  10. Analytical Model for the Probability Characteristics of a Crack Penetrating Capsules in Capsule-Based Self-Healing Cementitious Materials

    Directory of Open Access Journals (Sweden)

    Zhong LV

    2017-08-01

    Full Text Available Autonomous crack healing using pre-embedded capsules containing healing agent is becoming a promising approach to restore the strength of damaged structures. In addition to the material properties, the size and volume fraction of capsules influence crack healing in the matrix. Understanding the crack and capsule interaction is critical in the development and design of structures made of capsule-based self-healing materials. Continuing our previous study, in this contribution a more practical rupturing mode of capsules characterizing the rupturing manner of capsules fractured by cracks in cementitious materials is presented, i.e., penetrating mode. With the underlying assumption that a crack penetrating capsules undoubtedly leads to crack healing, geometrical probability theory is employed to develop the quantitative relationship between crack size and capsule size, capsule concentration in capsule-based self-healing virtual cementitious material. Moreover, an analytical expression of probability of a crack penetrating with randomly dispersed capsules is developed in two-dimensional material matrix setup. The influences of the induced rupturing modes of capsules embedded on the self-healing efficiency are analyzed. Much attention is paid to compare the penetrating probability and the hitting probability, in order to assist the designer to make a choice of the optimal rupturing modes of capsules embedded. The accuracy of results of the theoretical model is also compared with Monte-Carlo numerical analysis of crack interacting with capsules. It shows that the developed probability characteristics of a crack interaction with capsules for different rupturing modes is helpful to provide guidelines for designer working with capsule-based self-healing cementitious materials.DOI: http://dx.doi.org/10.5755/j01.ms.23.3.16888

  11. Computer software design description for the integrated control and data acquisition system LDUA system

    International Nuclear Information System (INIS)

    Aftanas, B.L.

    1998-01-01

    This Computer Software Design Description (CSDD) document provides the overview of the software design for all the software that is part of the integrated control and data acquisition system of the Light Duty Utility Arm System (LDUA). It describes the major software components and how they interface. It also references the documents that contain the detailed design description of the components

  12. Diversity requirements for safety critical software-based automation systems

    International Nuclear Information System (INIS)

    Korhonen, J.; Pulkkinen, U.; Haapanen, P.

    1998-03-01

    System vendors nowadays propose software-based systems even for the most critical safety functions in nuclear power plants. Due to the nature and mechanisms of influence of software faults new methods are needed for the safety and reliability evaluation of these systems. In the research project 'Programmable automation systems in nuclear power plants (OHA)' various safety assessment methods and tools for software based systems are developed and evaluated. This report first discusses the (common cause) failure mechanisms in software-based systems, then defines fault-tolerant system architectures to avoid common cause failures, then studies the various alternatives to apply diversity and their influence on system reliability. Finally, a method for the assessment of diversity is described. Other recently published reports in OHA-report series handles the statistical reliability assessment of software based (STUK-YTO-TR 119), usage models in reliability assessment of software-based systems (STUK-YTO-TR 128) and handling of programmable automation in plant PSA-studies (STUK-YTO-TR 129)

  13. The Systems Biology Research Tool: evolvable open-source software

    Directory of Open Access Journals (Sweden)

    Wright Jeremiah

    2008-06-01

    Full Text Available Abstract Background Research in the field of systems biology requires software for a variety of purposes. Software must be used to store, retrieve, analyze, and sometimes even to collect the data obtained from system-level (often high-throughput experiments. Software must also be used to implement mathematical models and algorithms required for simulation and theoretical predictions on the system-level. Results We introduce a free, easy-to-use, open-source, integrated software platform called the Systems Biology Research Tool (SBRT to facilitate the computational aspects of systems biology. The SBRT currently performs 35 methods for analyzing stoichiometric networks and 16 methods from fields such as graph theory, geometry, algebra, and combinatorics. New computational techniques can be added to the SBRT via process plug-ins, providing a high degree of evolvability and a unifying framework for software development in systems biology. Conclusion The Systems Biology Research Tool represents a technological advance for systems biology. This software can be used to make sophisticated computational techniques accessible to everyone (including those with no programming ability, to facilitate cooperation among researchers, and to expedite progress in the field of systems biology.

  14. The art of software thermal management for embedded systems

    CERN Document Server

    Benson, Mark

    2014-01-01

    This book introduces Software Thermal Management (STM) as a means of reducing power consumption in a computing system, in order to manage heat, improve component reliability, and increase system safety.  Readers will benefit from this pragmatic guide to the field of STM for embedded systems and its catalog of software power management techniques.  Since thermal management is a key bottleneck in embedded systems design, this book focuses on power as the root cause of heat. Since software has an enormous impact on power consumption in an embedded system, this book guides readers to manage heat effectively by understanding, categorizing, and developing new ways to reduce dynamic power. Whereas most books on thermal management describe mechanisms to remove heat, this book focuses on ways to avoid generating heat in the first place.   • Explains fundamentals of software thermal management, application techniques and advanced optimization strategies; • Describes a novel method for managing dynamic power, e...

  15. Application of automated reasoning software: procedure generation system verifier

    International Nuclear Information System (INIS)

    Smith, D.E.; Seeman, S.E.

    1984-09-01

    An on-line, automated reasoning software system for verifying the actions of other software or human control systems has been developed. It was demonstrated by verifying the actions of an automated procedure generation system. The verifier uses an interactive theorem prover as its inference engine with the rules included as logic axioms. Operation of the verifier is generally transparent except when the verifier disagrees with the actions of the monitored software. Testing with an automated procedure generation system demonstrates the successful application of automated reasoning software for verification of logical actions in a diverse, redundant manner. A higher degree of confidence may be placed in the verified actions gathered by the combined system

  16. A study of software safety analysis system for safety-critical software

    International Nuclear Information System (INIS)

    Chang, H. S.; Shin, H. K.; Chang, Y. W.; Jung, J. C.; Kim, J. H.; Han, H. H.; Son, H. S.

    2004-01-01

    The core factors and requirements for the safety-critical software traced and the methodology adopted in each stage of software life cycle are presented. In concept phase, Failure Modes and Effects Analysis (FMEA) for the system has been performed. The feasibility evaluation of selected safety parameter was performed and Preliminary Hazards Analysis list was prepared using HAZOP(Hazard and Operability) technique. And the check list for management control has been produced via walk-through technique. Based on the evaluation of the check list, activities to be performed in requirement phase have been determined. In the design phase, hazard analysis has been performed to check the safety capability of the system with regard to safety software algorithm using Fault Tree Analysis (FTA). In the test phase, the test items based on FMEA have been checked for fitness guided by an accident scenario. The pressurizer low pressure trip algorithm has been selected to apply FTA method to software safety analysis as a sample. By applying CASE tool, the requirements traceability of safety critical system has been enhanced during all of software life cycle phases

  17. AVNG System Software-Attribute Verification System with Information Barriers for Mass Isotopic Measurements

    International Nuclear Information System (INIS)

    Elmont, T.H.; Langner, Diana C.; MacArthur, D.W.; Mayo, D.R.; Smith, M.K.; Modenov, A.

    2005-01-01

    This report describes the software development for the plutonium attribute verification system - AVNG. A brief synopsis of the technical solution for the measurement system is presented. The main tasks for the software development that is underway are formulated. The development tasks are shown in software structural flowcharts, measurement system state diagram and a description of the software. The current status of the AVNG software development is elucidated.

  18. Characterization and modeling of three-dimensional self-healing shape memory alloy-reinforced metal-matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Manuel, Michele Viola [University of Florida, Gainesville; Zhu, Pingping [Northwestern University, Evanston; Newman, John A. [NASA Langely Research Center (LaRC), Virginia; Wright, M Clara [NASA Kennedy Space Center, FL; Brinson, L Catherine [Northwestern University, Evanston; Kesler, Michael S. [ORNL

    2016-09-10

    In this paper, three-dimensional metal-matrix composites (MMCs) reinforced by shape memory alloy (SMA) wires are modeled and simulated, by adopting an SMA constitutive model accounting for elastic deformation, phase transformation and plastic behavior. A modeling method to create composites with pre-strained SMA wires is also proposed to improve the self-healing ability. Experimental validation is provided with a composite under three-point bending. This modeling method is applied in a series of finite element simulations to investigate the self-healing effects in pre-cracked composites, especially the role of the SMA reinforcement, the softening property of the matrix, and the effect of pre-strain in the SMA. The results demonstrate that SMA reinforcements provide stronger shape recovery ability than other, non-transforming materials. The softening property of the metallic matrix and the pre-strain in SMA are also beneficial to help crack closure and healing. This modeling approach can serve as an efficient tool to design SMA-reinforced MMCs with optimal self-healing properties that have potential applications in components needing a high level of reliability.

  19. Optimization of process factors for self-healing vanadium-based conversion coating on AZ31 magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Kun; Liu, Junyao [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Lei, Ting, E-mail: tlei@mail.csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Xiao, Tao [2nd Xiangya Hospital, Central South University, Changsha 410011 (China)

    2015-10-30

    Highlights: • The optimum operating conditions were determined by an orthogonal experiment. • The coating is composed of oxides and hydroxides of V{sup 5+}, V{sup 4+} and Mg(OH){sub 2}. • The self-healing performance was investigated by cross-cut immersion test. • The vanadia conversion coating provided active corrosion protection to AZ31 alloy. - Abstract: A self-healing vanadium-based conversion coating was prepared on AZ31 magnesium alloy. The optimum operating conditions including vanadia solution concentration, pH and treating temperature for obtaining the best corrosion protective vanadia coatings and improved localized corrosion resistance to the magnesium substrate were determined by an orthogonal experiment design. Surface morphology and composition of the resultant conversion coatings were investigated by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The self-healing behavior of the coating was investigated by cross-cut immersion test and electrochemical impedance spectroscopy (EIS) measurements in 3.5% NaCl solution.

  20. Optimization of process factors for self-healing vanadium-based conversion coating on AZ31 magnesium alloy

    International Nuclear Information System (INIS)

    Li, Kun; Liu, Junyao; Lei, Ting; Xiao, Tao

    2015-01-01

    Highlights: • The optimum operating conditions were determined by an orthogonal experiment. • The coating is composed of oxides and hydroxides of V"5"+, V"4"+ and Mg(OH)_2. • The self-healing performance was investigated by cross-cut immersion test. • The vanadia conversion coating provided active corrosion protection to AZ31 alloy. - Abstract: A self-healing vanadium-based conversion coating was prepared on AZ31 magnesium alloy. The optimum operating conditions including vanadia solution concentration, pH and treating temperature for obtaining the best corrosion protective vanadia coatings and improved localized corrosion resistance to the magnesium substrate were determined by an orthogonal experiment design. Surface morphology and composition of the resultant conversion coatings were investigated by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The self-healing behavior of the coating was investigated by cross-cut immersion test and electrochemical impedance spectroscopy (EIS) measurements in 3.5% NaCl solution.

  1. Dual Cross-Linked Biofunctional and Self-Healing Networks to Generate User-Defined Modular Gradient Hydrogel Constructs.

    Science.gov (United States)

    Wei, Zhao; Lewis, Daniel M; Xu, Yu; Gerecht, Sharon

    2017-08-01

    Gradient hydrogels have been developed to mimic the spatiotemporal differences of multiple gradient cues in tissues. Current approaches used to generate such hydrogels are restricted to a single gradient shape and distribution. Here, a hydrogel is designed that includes two chemical cross-linking networks, biofunctional, and self-healing networks, enabling the customizable formation of modular gradient hydrogel construct with various gradient distributions and flexible shapes. The biofunctional networks are formed via Michael addition between the acrylates of oxidized acrylated hyaluronic acid (OAHA) and the dithiol of matrix metalloproteinase (MMP)-sensitive cross-linker and RGD peptides. The self-healing networks are formed via dynamic Schiff base reaction between N-carboxyethyl chitosan (CEC) and OAHA, which drives the modular gradient units to self-heal into an integral modular gradient hydrogel. The CEC-OAHA-MMP hydrogel exhibits excellent flowability at 37 °C under shear stress, enabling its injection to generate gradient distributions and shapes. Furthermore, encapsulated sarcoma cells respond to the gradient cues of RGD peptides and MMP-sensitive cross-linkers in the hydrogel. With these superior properties, the dual cross-linked CEC-OAHA-MMP hydrogel holds significant potential for generating customizable gradient hydrogel constructs, to study and guide cellular responses to their microenvironment such as in tumor mimicking, tissue engineering, and stem cell differentiation and morphogenesis. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Soft Asphalt and Double Otta Seal—Self-Healing Sustainable Techniques for Low-Volume Gravel Road Rehabilitation

    Directory of Open Access Journals (Sweden)

    Audrius Vaitkus

    2018-01-01

    Full Text Available Increased traffic flow on low-volume gravel roads and deficiencies of national road infrastructure, are increasingly apparent in Lithuania. Gravel roads do not comply with requirements, resulting in low driving comfort, longer travelling time, faster vehicle amortization, and dustiness. The control of dustiness is one of the most important road maintenance activities on gravel roads. Another important issue is the assurance of required driving comfort and safety. Soft asphalt and Otta Seal technologies were proposed as a sustainable solution for the improvement of low-volume roads in Lithuania. Five gravel roads were constructed with soft asphalt, and 13 gravel roads were sealed with double Otta Seal, in 2012. The main aim of this research was to check soft asphalt and double Otta Seal’s ability to self-heal, on the basis of the results of the qualitative visual assessment of pavement defects and distress. The qualitative visual assessment was carried out twice a year following the opening of the rehabilitated road sections. The results confirmed soft asphalt and double Otta Seal’s ability to self-heal. The healing effect was more than 13% and 19% on roads with soft asphalt and double Otta Seal, respectively. In addition, on some roads, all cracks observed in spring self-healed during summer.

  3. A Study on the Manufacturing Properties of Crack Self-Healing Capsules Using Cement Powder for Addition to Cement Composites

    Directory of Open Access Journals (Sweden)

    Yun-Wang Choi

    2017-01-01

    Full Text Available We fabricated crack self-healing capsules using cement powder for mixing into cement composites and evaluated the properties of the capsule manufacturing process in this study. The manufacture of the self-healing capsules is divided into core production processing of granulating cement in powder form and a coating process for creating a wall on the surfaces of the granulated cement particles. The produced capsules contain unhardened cement and can be mixed directly with the cement composite materials because they are protected from moisture by the wall material. Therefore, the untreated cement is present in the form of a capsule within the cement composite, and hydration can be induced by moisture penetrating the crack surface in the event of cracking. In the process of granulating the cement, it is important to obtain a suitable consistency through the kneading agent and to maintain the moisture barrier performance of the wall material. We can utilize the results of this study as a basis for advanced self-healing capsule technology for cement composites.

  4. Customizable software architectures in the accelerator control system environment

    CERN Document Server

    Mejuev, I; Kadokura, E

    2001-01-01

    Tailoring is further evolution of an application after deployment in order to adapt it to requirements that were not accounted for in the original design. End-user customization has been extensively researched in applied computer science from HCI and software engineering perspectives. Customization allows coping with flexibility requirements, decreasing maintenance and development costs of software products. In general, dynamic or diverse software requirements constitute the need for implementing end-user customization in computer systems. In accelerator physics research the factor of dynamic requirements is especially important, due to frequent software and hardware modifications resulting in correspondingly high upgrade and maintenance costs. We introduce the results of feasibility study on implementing end-user tailorability in the software for accelerator control system, considering the design and implementation of a distributed monitoring application for the 12 GeV KEK Proton Synchrotron as an example. T...

  5. In Forming Software: Systems, Structuralism, Demythification

    Directory of Open Access Journals (Sweden)

    Edward A. Shanken

    2014-05-01

    Full Text Available In the mid-1960s, Marshall McLuhan prophesied that electronic media were creating an increasingly interconnected global village. Such pronouncements popularized the idea that the era of machine-age technology was drawing to a close, ushering in a new era of information technology. This shift finds parallels in a wave of major art performances and exhibitions between 1966-1970, including nine evenings: theatre and engineering at the New York Armory, spearheaded by Robert Rauschenberg, Billy Klüver, and Robert Whitman in 1966; The Machine: As Seen at the End of the Mechanical Age, curated by Pontus Hultén at the Museum of Modern Art in New York (MOMA in 1968; Cybernetic Serendipity, curated by Jasia Reichardt at the Institute of Contemporary Art in London in 1968; and Software, Information Technology: Its New Meaning for Art, curated by Jack Burnham at the Jewish Museum in New York.

  6. MEMbrain. A software emergency management system

    International Nuclear Information System (INIS)

    Drager, K.H.; Brokke, I.

    1998-01-01

    MEMbrain is the name of the EUREKA project EU904. MEM is an abbreviation for Major Emergency Management and brain refers to computer technology. MEMbrain is a strategic European project - the consortium includes partners from six countries, covering the European continent from North to South (Finland, Norway, Denmark, France, Portugal and Greece). The strategy for the project has been to develop a dynamic decision support tool based on: information, prediction, communication, on-line training. The project's results has resulted in a set of knowledge-based software tools supporting MEM activities e.g.; public protection management, man to man communication management, environment information management, resource management, as well as an implementation of an architecture to integrate such tools. (R.P.)

  7. Software control and system configuration management - A process that works

    Science.gov (United States)

    Petersen, K. L.; Flores, C., Jr.

    1983-01-01

    A comprehensive software control and system configuration management process for flight-crucial digital control systems of advanced aircraft has been developed and refined to insure efficient flight system development and safe flight operations. Because of the highly complex interactions among the hardware, software, and system elements of state-of-the-art digital flight control system designs, a systems-wide approach to configuration control and management has been used. Specific procedures are implemented to govern discrepancy reporting and reconciliation, software and hardware change control, systems verification and validation testing, and formal documentation requirements. An active and knowledgeable configuration control board reviews and approves all flight system configuration modifications and revalidation tests. This flexible process has proved effective during the development and flight testing of several research aircraft and remotely piloted research vehicles with digital flight control systems that ranged from relatively simple to highly complex, integrated mechanizations.

  8. From conventional software based systems to knowledge based systems

    International Nuclear Information System (INIS)

    Bologna, S.

    1995-01-01

    Even if todays nuclear power plants have a very good safety record, there is a continuous search for still improving safety. One direction of this effort address operational safety, trying to improve the handling of disturbances and accidents partly by further automation, partly by creating a better control room environment, providing the operator with intelligent support systems to help in the decision making process. Introduction of intelligent computerised operator support systems has proved to be an efficient way of improving the operators performance. A number of systems have been developed worldwide, assisting in tasks like process fault detection and diagnosis, selection and implementation of proper remedial actions. Unfortunately, the use of Knowledge Based Systems (KBSs), introduces a new dimension to the problem of the licensing process. KBSs, despite the different technology employed, are still nothing more than a computer program. Unfortunately, quite a few people building knowledge based systems seem to ignore the many good programming practices that have evolved over the years for producing traditional computer programs. In this paper the author will try to point out similarities and differences between conventional software based systems, and knowledge based systems, introducing also the concept of model based reasoning. (orig.) (25 refs., 2 figs.)

  9. Towards a lessons learned system for critical software

    International Nuclear Information System (INIS)

    Andrade, J.; Ares, J.; Garcia, R.; Pazos, J.; Rodriguez, S.; Rodriguez-Paton, A.; Silva, A.

    2007-01-01

    Failure can be a major driver for the advance of any engineering discipline and Software Engineering is no exception. But failures are useful only if lessons are learned from them. In this article we aim to make a strong defence of, and set the requirements for, lessons learned systems for safety-critical software. We also present a prototype lessons learned system that includes many of the features discussed here. We emphasize that, apart from individual organizations, lessons learned systems should target industrial sectors and even the Software Engineering community. We would like to encourage the Software Engineering community to use this kind of systems as another tool in the toolbox, which complements or enhances other approaches like, for example, standards and checklists

  10. The Fox Project: Advanced Development of Systems Software

    National Research Council Canada - National Science Library

    1999-01-01

    The long-term objectives of the Carnegie Mellon Fox Project are to improve the design and construction of systems software and to further the development of advanced programming language technology...

  11. The Fox Project: Advanced Development of Systems Software

    National Research Council Canada - National Science Library

    2000-01-01

    The long-term objectives of the Carnegie Mellon Fox Project are to improve the design and construction of systems software and to further the development of advanced programming language technology...

  12. Towards a lessons learned system for critical software

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, J. [University of A Coruna. Campus de Elvina, s/n. 15071, A Coruna (Spain)]. E-mail: jag@udc.es; Ares, J. [University of A Coruna. Campus de Elvina, s/n. 15071, A Coruna (Spain)]. E-mail: juanar@udc.es; Garcia, R. [University of A Coruna. Campus de Elvina, s/n. 15071, A Coruna (Spain)]. E-mail: rafael@udc.es; Pazos, J. [Technical University of Madrid. Campus de Montegancedo, s/n. 28660, Boadilla del Monte, Madrid (Spain)]. E-mail: jpazos@fi.upm.es; Rodriguez, S. [University of A Coruna. Campus de Elvina, s/n. 15071, A Coruna (Spain)]. E-mail: santi@udc.es; Rodriguez-Paton, A. [Technical University of Madrid. Campus de Montegancedo, s/n. 28660, Boadilla del Monte, Madrid (Spain)]. E-mail: arpaton@fi.upm.es; Silva, A. [Technical University of Madrid. Campus de Montegancedo, s/n. 28660, Boadilla del Monte, Madrid (Spain)]. E-mail: asilva@fi.upm.es

    2007-07-15

    Failure can be a major driver for the advance of any engineering discipline and Software Engineering is no exception. But failures are useful only if lessons are learned from them. In this article we aim to make a strong defence of, and set the requirements for, lessons learned systems for safety-critical software. We also present a prototype lessons learned system that includes many of the features discussed here. We emphasize that, apart from individual organizations, lessons learned systems should target industrial sectors and even the Software Engineering community. We would like to encourage the Software Engineering community to use this kind of systems as another tool in the toolbox, which complements or enhances other approaches like, for example, standards and checklists.

  13. The Utility of Open Source Software in Military Systems

    National Research Council Canada - National Science Library

    Esperon, Agustin I; Munoz, Jose P; Tanneau, Jean M

    2005-01-01

    The MILOS (Military Systems based on Open-source Software) project was a European research program in the Eurofinder framework, attached to the CEPA 6 and co-financed by the Ministry of Defence of France and Spain...

  14. Hardware-assisted software clock synchronization for homogeneous distributed systems

    Science.gov (United States)

    Ramanathan, P.; Kandlur, Dilip D.; Shin, Kang G.

    1990-01-01

    A clock synchronization scheme that strikes a balance between hardware and software solutions is proposed. The proposed is a software algorithm that uses minimal additional hardware to achieve reasonably tight synchronization. Unlike other software solutions, the guaranteed worst-case skews can be made insensitive to the maximum variation of message transit delay in the system. The scheme is particularly suitable for large partially connected distributed systems with topologies that support simple point-to-point broadcast algorithms. Examples of such topologies include the hypercube and the mesh interconnection structures.

  15. Development of design and analysis software for advanced nuclear system

    International Nuclear Information System (INIS)

    Wu Yican; Hu Liqin; Long Pengcheng; Luo Yuetong; Li Yazhou; Zeng Qin; Lu Lei; Zhang Junjun; Zou Jun; Xu Dezheng; Bai Yunqing; Zhou Tao; Chen Hongli; Peng Lei; Song Yong; Huang Qunying

    2010-01-01

    A series of professional codes, which are necessary software tools and data libraries for advanced nuclear system design and analysis, were developed by the FDS Team, including the codes of automatic modeling, physics and engineering calculation, virtual simulation and visualization, system engineering and safety analysis and the related database management etc. The development of these software series was proposed as an exercise of development of nuclear informatics. This paper introduced the main functions and key techniques of the software series, as well as some tests and practical applications. (authors)

  16. Qt based control system software for Low Energy Accelerator Facility

    International Nuclear Information System (INIS)

    Basu, A.; Singh, S.; Nagraju, S.B.V.; Gupta, S.; Singh, P.

    2012-01-01

    Qt based control system software for Low Energy Accelerating Facility (LEAF) is operational at Bhabha Atomic Research Centre (BARC), Trombay, Mumbai. LEAF is a 50 keV negative ion electrostatic accelerator based on SNICS ion source. Control system uses Nokia Trolltech's QT 4.x API for control system software. Ni 6008 USB based multifunction cards has been used for control and read back field equipments such as power supplies, pumps, valves etc. Control system architecture is designed to be client server. Qt is chosen for its excellent GUI capability and platform independent nature. Control system follows client server architecture. The paper will describe the control system. (author)

  17. Radioisotope thermoelectric generator transportation system subsystem 143 software development plan

    International Nuclear Information System (INIS)

    King, D.A.

    1994-01-01

    This plan describes the activities to be performed and the controls to be applied to the process of specifying, developing, and qualifying the data acquisition software for the Radioisotope Thermoelectric Generator (RTG) Transportation System Subsystem 143 Instrumentation and Data Acquisition System (IDAS). This plan will serve as a software quality assurance plan, a verification and validation (V and V) plan, and a configuration management plan

  18. A Reference Model for Software and System Inspections. White Paper

    Science.gov (United States)

    He, Lulu; Shull, Forrest

    2009-01-01

    Software Quality Assurance (SQA) is an important component of the software development process. SQA processes provide assurance that the software products and processes in the project life cycle conform to their specified requirements by planning, enacting, and performing a set of activities to provide adequate confidence that quality is being built into the software. Typical techniques include: (1) Testing (2) Simulation (3) Model checking (4) Symbolic execution (5) Management reviews (6) Technical reviews (7) Inspections (8) Walk-throughs (9) Audits (10) Analysis (complexity analysis, control flow analysis, algorithmic analysis) (11) Formal method Our work over the last few years has resulted in substantial knowledge about SQA techniques, especially the areas of technical reviews and inspections. But can we apply the same QA techniques to the system development process? If yes, what kind of tailoring do we need before applying them in the system engineering context? If not, what types of QA techniques are actually used at system level? And, is there any room for improvement.) After a brief examination of the system engineering literature (especially focused on NASA and DoD guidance) we found that: (1) System and software development process interact with each other at different phases through development life cycle (2) Reviews are emphasized in both system and software development. (Figl.3). For some reviews (e.g. SRR, PDR, CDR), there are both system versions and software versions. (3) Analysis techniques are emphasized (e.g. Fault Tree Analysis, Preliminary Hazard Analysis) and some details are given about how to apply them. (4) Reviews are expected to use the outputs of the analysis techniques. In other words, these particular analyses are usually conducted in preparation for (before) reviews. The goal of our work is to explore the interaction between the Quality Assurance (QA) techniques at the system level and the software level.

  19. Advanced Transport Operating System (ATOPS) utility library software description

    Science.gov (United States)

    Clinedinst, Winston C.; Slominski, Christopher J.; Dickson, Richard W.; Wolverton, David A.

    1993-01-01

    The individual software processes used in the flight computers on-board the Advanced Transport Operating System (ATOPS) aircraft have many common functional elements. A library of commonly used software modules was created for general uses among the processes. The library includes modules for mathematical computations, data formatting, system database interfacing, and condition handling. The modules available in the library and their associated calling requirements are described.

  20. Software for Intelligent System Health Management

    Science.gov (United States)

    Trevino, Luis C.

    2004-01-01

    This viewgraph presentation describes the characteristics and advantages of autonomy and artificial intelligence in systems health monitoring. The presentation lists technologies relevant to Intelligent System Health Management (ISHM), and some potential applications.