WorldWideScience

Sample records for repairing material systems

  1. Self-repair of cracks in brittle material systems

    Science.gov (United States)

    Dry, Carolyn M.

    2016-04-01

    One of the most effective uses for self repair is in material systems that crack because the cracks can allow the repair chemical to flow into the crack damage sites in all three dimensions. In order for the repair chemical to stay in the damage site and flow along to all the crack and repair there must be enough chemical to fill the entire crack. The repair chemical must be designed appropriately for the particular crack size and total volume of cracks. In each of the three examples of self repair in crackable brittle systems, the viscosity and chemical makeup and volume of the repair chemicals used is different for each system. Further the chemical delivery system has to be designed for each application also. Test results from self repair of three brittle systems are discussed. In "Self Repair of Concrete Bridges and Infrastructure" two chemicals were used due to different placements in bridges to repair different types of cracks- surface shrinkage and shear cracks, In "Airplane Wings and Fuselage, in Graphite" the composite has very different properties than the concrete bridges. In the graphite for airplane components the chemical also had to survive the high processing temperatures. In this composite the cracks were so definite and deep and thin that the repair chemical could flow easily and repair in all layers of the composite. In "Ceramic/Composite Demonstrating Self Repair" the self repair system not only repaired the broken ceramic but also rebounded the composite to the ceramic layer

  2. Materials directed to implants for repairing Central Nervous System

    Directory of Open Access Journals (Sweden)

    Canillas, M.

    2014-12-01

    Full Text Available Central Nervous System (CNS can be damaged by a wide range of injuries and disorders which entail permanent disability in some cases. Moreover, CNS repairing process presents some complications. The natural repair mechanism, which consists on the glial scar formation, is triggered by the inflammatory process. Molecules delivered during these processes, inflammation and glial scar formation as well as oxygen and glucose deficiencies due to the injury, create an inhibitory environment for axon regeneration and remyelination which is known as “secondary injury”. Biomaterials are taking up an even more important role in repairing CNS. Physicochemical properties of some ceramic materials have inspired different applications to repair CNS as substrates, electrodes or molecule vehicles. Based on their biocompatibility, capability to neutralize reactive species involved in the inflammatory processes and their versatile processing to obtain scaffolds with different shapes and sizes, ceramics are a succulent offer in nervous tissue engineering. Furthermore, their possibilities have been increased with polymeric-ceramics composites development, which have given rise to new interesting horizon.Existen diferentes tipos de lesiones o desordenes del Sistema Nervioso Central (SNC que pueden provocar graves secuelas e incluso en algunos casos una discapacidad permanente. Además, el proceso de reparación del SNC tiene algunas complicaciones. El mecanismo natural de reacción a una lesión, el cual consiste en la formación de una cicatriz glial, es desencadenado por un proceso inflamatorio. Las moléculas liberadas durante estos procesos, la inflamación y formación de la cicatriz glial, así como la deficiencia en oxígeno y glucosa debidos a la lesión, crean un ambiente que inhibe la regeneración axonal creando la llamada “lesión secundaria”. Los biomateriales están adquiriendo un papel cada vez más importante en la reparación de SNC. Las

  3. In Vitro Comparison of the Bond Strength between Ceramic Repair Systems and Ceramic Materials and Evaluation of the Wettability.

    Science.gov (United States)

    Kocaağaoğlu, Hasan; Manav, Taha; Albayrak, Haydar

    2017-04-01

    When fracture of an all-ceramic restoration occurs, it can be necessary to repair without removing the restoration. Although there are many studies about the repair of metal-ceramic restorations, there are few about all-ceramic restorations. The aim of this study was to evaluate the shear bond strength between ceramic repair systems and esthetic core materials and to evaluate the wettability of all-ceramic core materials. Disk-like specimens (N = 90) made of three dental ceramic infrastructure materials (zirconia ceramic, alumina ceramic, glass ceramic) were polished with silicon carbide paper, prepared for bonding (abrasion with 30 μm diamond rotary cutting instrument). Thirty specimens of each infrastructure were obtained. Each infrastructure group was divided into three subgroups; they were bonded using 3 repair systems: Bisco Intraoral Repair Kit, Cimara & Cimara Zircon Repair System, and Clearfil Repair System. After 1200 thermocycles, shear bond strength was measured in a universal testing machine at a 0.5 mm/min crosshead speed. In addition, the contact angle values of the infrastructures after surface treatments were examined for wettability. Data were analyzed by using ANOVA and Tukey post hoc tests. Although there were no significant differences among the repair systems (p > 0.05) in the glass ceramic and zirconia groups, a significant difference was found among the repair systems in alumina infrastructure (p 0.05); however, a statistically significant difference was found among the repair systems (p < 0.05). No difference was found among the infrastructures and repair systems in terms of contact angle values. Cimara & Cimara Zircon Repair System had higher bond strength values than the other repair systems. Although no difference was found among the infrastructures and repair systems, contact wettability angle was decreased by surface treatments compared with polished surfaces. © 2015 by the American College of Prosthodontists.

  4. Study of the performance of four repairing material systems for hydraulic structures of concrete dams

    Directory of Open Access Journals (Sweden)

    Kormann A. C. M.

    2003-01-01

    Full Text Available Four types of repairing materials are studied as function of either a conventional concrete or a reference-concrete (RefC, these are: polymer-modified cement mortar (PMor, steel fiber concrete (SFco, epoxy mortar (EMor and silica fume mortar (SFmo, to be applied in hydraulic structures surfaces subjected to a high velocity water flow. Besides the mechanical requests and wearing resistance of hydraulic concrete dam structures, especially the spillway surfaces, the high solar radiation, the environmental temperature and wet and dry cycles, contribute significantly to the reduction of their lifespan. RefC and the SFco were developed based on a usual concrete mixture used in slabs of spillways. The average RefC mixture used was 1: 1.61: 2.99: 0.376, with Pozzolan-modified Portland cement consumption of 425 kg/m³. EMor and PMor mixtures followed the information given by the manufacturers and lab experience. Tests on concrete samples were carried out in laboratory simulating normally found environmental situations in order to control the mechanical resistance and the aging imposed conditions, such as solar radiation and humidity. Also, physicochemical characterizing tests were made for all used materials. From the analyzed results, two of them presented a higher performance: the EMor and SFmo. SFco presented good adherence to the RefC and good mechanical performance. However, it also presented apparent metal corrosion in humidity tests, being indicated for use, with caution, as an intermediate layer in underwater repairs. In a general classification, considering all tests, including their field applications, the better performance material systems were EMor- SFmo> SFco> PMor.

  5. Energy-dissipating and self-repairing SMA-ECC composite material system

    International Nuclear Information System (INIS)

    Li, Xiaopeng; Li, Mo; Song, Gangbing

    2015-01-01

    Structural component ductility and energy dissipation capacity are crucial factors for achieving reinforced concrete structures more resistant to dynamic loading such as earthquakes. Furthermore, limiting post-event residual damage and deformation allows for immediate re-operation or minimal repairs. These desirable characteristics for structural ‘resilience’, however, present significant challenges due to the brittle nature of concrete, its deformation incompatibility with ductile steel, and the plastic yielding of steel reinforcement. Here, we developed a new composite material system that integrates the unique ductile feature of engineered cementitious composites (ECC) with superelastic shape memory alloy (SMA). In contrast to steel reinforced concrete (RC) and SMA reinforced concrete (SMA-RC), the SMA-ECC beams studied in this research exhibited extraordinary energy dissipation capacity, minimal residual deformation, and full self-recovery of damage under cyclic flexural loading. We found that the tensile strain capacity of ECC, tailored up to 5.5% in this study, allows it to work compatibly with superelastic SMA. Furthermore, the distributed microcracking damage mechanism in ECC is critical for sufficient and reliable recovery of damage upon unloading. This research demonstrates the potential of SMA-ECC for improving resilience of concrete structures under extreme hazard events. (paper)

  6. Outreach Materials for the Collision Repair Campaign

    Science.gov (United States)

    The Collision Repair Campaign offers outreach materials to help collision repair shops reduce toxic air exposure. Materials include a DVD, poster, training video, and materials in Spanish (materiales del outreach en español).

  7. Wellbore Seal Repair Using Nanocomposite Materials

    Energy Technology Data Exchange (ETDEWEB)

    Stormont, John [Univ. of New Mexico, Albuquerque, NM (United States)

    2016-08-31

    Nanocomposite wellbore repair materials have been developed, tested, and modeled through an integrated program of laboratory testing and numerical modeling. Numerous polymer-cement nanocomposites were synthesized as candidate wellbore repair materials using various combinations of base polymers and nanoparticles. Based on tests of bond strength to steel and cement, ductility, stability, flowability, and penetrability in opening of 50 microns and less, we identified Novolac epoxy reinforced with multi-walled carbon nanotubes and/or alumina nanoparticles to be a superior wellbore seal material compared to conventional microfine cements. A system was developed for testing damaged and repaired wellbore specimens comprised of a cement sheath cast on a steel casing. The system allows independent application of confining pressures and casing pressures while gas flow is measured through the specimens along the wellbore axis. Repair with the nanocomposite epoxy base material was successful in dramatically reducing the flow through flaws of various sizes and types, and restoring the specimen comparable to an intact condition. In contrast, repair of damaged specimens with microfine cement was less effective, and the repair degraded with application of stress. Post-test observations confirm the complete penetration and sealing of flaws using the nanocomposite epoxy base material. A number of modeling efforts have supported the material development and testing efforts. We have modeled the steel-repair material interface behavior in detail during slant shear tests, which we used to characterize bond strength of candidate repair materials. A numerical model of the laboratory testing of damaged wellbore specimens was developed. This investigation found that microannulus permeability can satisfactorily be described by a joint model. Finally, a wellbore model has been developed that can be used to evaluate the response of the wellbore system (casing, cement, and microannulus

  8. Composite Repair System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — GTL has developed an innovative composite repair methodology known as the Composite Repair System (CRS). In this phase I effort, CRS is being developed for the...

  9. DNA Repair Systems

    Indian Academy of Sciences (India)

    DNA molecule which makes it ideal for storage and propagation of genetic information. ... of these errors are broadly referred to as DNA repair. DNA can ... changes occur in the human genome per day. ..... nails, frequent physical and mental.

  10. Failure Modes in Concrete Repair Systems due to Ongoing Corrosion

    Directory of Open Access Journals (Sweden)

    Mladena Luković

    2017-01-01

    Full Text Available Corrosion of steel reinforcement is the main cause of deterioration in reinforced concrete structures. It can result in cracking and spalling of the concrete cover. After the damaged cover is repaired, reinforcement corrosion might continue and even accelerate. While the development of the corrosion cell is difficult to control, the damage can be possibly delayed and controlled by use of a suitable repair material. The lattice fracture model is used in this paper to investigate the performance of strain hardening cementitious composite (SHCC in concrete repair systems exposed to ongoing corrosion. Numerical results were verified by experimental tests when SHCC, nonreinforced material (repair mortar, and commercial repair mortar are used as repair materials. In experiments, reinforcement bars (surrounded by a repair material were exposed to accelerated corrosion tests. The influence of the substrate surface preparation, the type of repair material, the interface, and the substrate strength on the resulting damage and failure mode of repair systems are discussed. In general, SHCC repair enables distributed cracking with small crack widths, up to several times smaller compared to repair mortar. Furthermore, more warning signs prior to the final failure are present in the SHCC repair system.

  11. DNA Repair Systems

    Indian Academy of Sciences (India)

    Thanks to the pioneering research work of Lindahl, Sancar, Modrich and their colleagues, we now have an holistic awareness of how DNA damage occurs and how the damage is rectified in bacteria as well as in higher organisms including human beings. A comprehensive understanding of DNA repair has proven crucial ...

  12. Systems Maintenance Automated Repair Tasks (SMART)

    Science.gov (United States)

    Schuh, Joseph; Mitchell, Brent; Locklear, Louis; Belson, Martin A.; Al-Shihabi, Mary Jo Y.; King, Nadean; Norena, Elkin; Hardin, Derek

    2010-01-01

    SMART is a uniform automated discrepancy analysis and repair-authoring platform that improves technical accuracy and timely delivery of repair procedures for a given discrepancy (see figure a). SMART will minimize data errors, create uniform repair processes, and enhance the existing knowledge base of engineering repair processes. This innovation is the first tool developed that links the hardware specification requirements with the actual repair methods, sequences, and required equipment. SMART is flexibly designed to be useable by multiple engineering groups requiring decision analysis, and by any work authorization and disposition platform (see figure b). The organizational logic creates the link between specification requirements of the hardware, and specific procedures required to repair discrepancies. The first segment in the SMART process uses a decision analysis tree to define all the permutations between component/ subcomponent/discrepancy/repair on the hardware. The second segment uses a repair matrix to define what the steps and sequences are for any repair defined in the decision tree. This segment also allows for the selection of specific steps from multivariable steps. SMART will also be able to interface with outside databases and to store information from them to be inserted into the repair-procedure document. Some of the steps will be identified as optional, and would only be used based on the location and the current configuration of the hardware. The output from this analysis would be sent to a work authoring system in the form of a predefined sequence of steps containing required actions, tools, parts, materials, certifications, and specific requirements controlling quality, functional requirements, and limitations.

  13. Bioactive Polymeric Materials for Tissue Repair

    Directory of Open Access Journals (Sweden)

    Diane R. Bienek

    2017-01-01

    Full Text Available Bioactive polymeric materials based on calcium phosphates have tremendous appeal for hard tissue repair because of their well-documented biocompatibility. Amorphous calcium phosphate (ACP-based ones additionally protect against unwanted demineralization and actively support regeneration of hard tissue minerals. Our group has been investigating the structure/composition/property relationships of ACP polymeric composites for the last two decades. Here, we present ACP’s dispersion in a polymer matrix and the fine-tuning of the resin affects the physicochemical, mechanical, and biological properties of ACP polymeric composites. These studies illustrate how the filler/resin interface and monomer/polymer molecular structure affect the material’s critical properties, such as ion release and mechanical strength. We also present evidence of the remineralization efficacy of ACP composites when exposed to accelerated acidic challenges representative of oral environment conditions. The utility of ACP has recently been extended to include airbrushing as a platform technology for fabrication of nanofiber scaffolds. These studies, focused on assessing the feasibility of incorporating ACP into various polymer fibers, also included the release kinetics of bioactive calcium and phosphate ions from nanofibers and evaluate the biorelevance of the polymeric ACP fiber networks. We also discuss the potential for future integration of the existing ACP scaffolds into therapeutic delivery systems used in the precision medicine field.

  14. 21 CFR 870.3710 - Pacemaker repair or replacement material.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is an...

  15. Reward optimization of a repairable system

    Energy Technology Data Exchange (ETDEWEB)

    Castro, I.T. [Departamento de Matematicas, Facultad de Veterinaria, Universidad de Extremadura, Avenida de la Universidad, s/n. 10071 Caceres (Spain)]. E-mail: inmatorres@unex.es; Perez-Ocon, R. [Departamento de Estadistica e Investigacion Operativa, Facultad de Ciencias, Universidad de Granada, Avenida de Severo Ochoa, s/n. 18071 Granada (Spain)]. E-mail: rperezo@ugr.es

    2006-03-15

    This paper analyzes a system subject to repairable and non-repairable failures. Non-repairable failures lead to replacement of the system. Repairable failures, first lead to repair but they lead to replacement after a fixed number of repairs. Operating and repair times follow phase type distributions (PH-distributions) and the pattern of the operating times is modelled by a geometric process. In this context, the problem is to find the optimal number of repairs, which maximizes the long-run average reward per unit time. To this end, the optimal number is determined and it is obtained by efficient numerical procedures.

  16. Reward optimization of a repairable system

    International Nuclear Information System (INIS)

    Castro, I.T.; Perez-Ocon, R.

    2006-01-01

    This paper analyzes a system subject to repairable and non-repairable failures. Non-repairable failures lead to replacement of the system. Repairable failures, first lead to repair but they lead to replacement after a fixed number of repairs. Operating and repair times follow phase type distributions (PH-distributions) and the pattern of the operating times is modelled by a geometric process. In this context, the problem is to find the optimal number of repairs, which maximizes the long-run average reward per unit time. To this end, the optimal number is determined and it is obtained by efficient numerical procedures

  17. An Overview of Corroded Pipe Repair Techniques Using Composite Materials

    OpenAIRE

    K. S. Lim; S. N. A. Azraai; N. M. Noor; N. Yahaya

    2015-01-01

    Polymeric composites are being increasingly used as repair material for repairing critical infrastructures such as building, bridge, pressure vessel, piping and pipeline. Technique in repairing damaged pipes is one of the major concerns of pipeline owners. Considerable researches have been carried out on the repair of corroded pipes using composite materials. This article attempts a short review of the subject matter to provide insight into various techniques used in repa...

  18. Novel Repair Concept for Composite Materials by Repetitive Geometrical Interlock Elements

    Directory of Open Access Journals (Sweden)

    David Zaremba

    2011-12-01

    Full Text Available Material adapted repair technologies for fiber-reinforced polymers with thermosetting matrix systems are currently characterized by requiring major efforts for repair preparation and accomplishment in all industrial areas of application. In order to allow for a uniform distribution of material and geometrical parameters over the repair zone, a novel composite interlock repair concept is introduced, which is based on a repair zone with undercuts prepared by water-jet technology. The presented numerical and experimental sensitivity analyses make a contribution to the systematic development of the interlock repair technology with respect to material and geometrical factors of influence. The results show the ability of the novel concept for a reproducible and automatable composite repair.

  19. Effect of Moisture Exchange on Interface Formation in the Repair System Studied by X-ray Absorption

    NARCIS (Netherlands)

    Lukovic, M.; Ye, G.

    2015-01-01

    In concrete repair systems, material properties of the repair material and the interface are greatly influenced by the moisture exchange between the repair material and the substrate. If the substrate is dry, it can absorb water from the repair material and reduce its effective water-to-cement ratio

  20. Autogenous Metallic Pipe Leak Repair in Potable Water Systems.

    Science.gov (United States)

    Tang, Min; Triantafyllidou, Simoni; Edwards, Marc A

    2015-07-21

    Copper and iron pipes have a remarkable capability for autogenous repair (self-repair) of leaks in potable water systems. Field studies revealed exemplars that metallic pipe leaks caused by nails, rocks, and erosion corrosion autogenously repaired, as confirmed in the laboratory experiments. This work demonstrated that 100% (N = 26) of 150 μm leaks contacting representative bulk potable water in copper pipes sealed autogenously via formation of corrosion precipitates at 20-40 psi, pH 3.0-11.0, and with upward and downward leak orientations. Similar leaks in carbon steel pipes at 20 psi self-repaired at pH 5.5 and 8.5, but two leaks did not self-repair permanently at pH 11.0 suggesting that water chemistry may control the durability of materials that seal the leaks and therefore the permanence of repair. Larger 400 μm holes in copper pipes had much lower (0-33%) success of self-repair at pH 3.0-11.0, whereas all 400 μm holes in carbon steel pipes at 20 psi self-repaired at pH 4.0-11.0. Pressure tests indicated that some of the repairs created at 20-40 psi ambient pressure could withstand more than 100 psi without failure. Autogenous repair has implications for understanding patterns of pipe failures, extending the lifetime of decaying infrastructure, and developing new plumbing materials.

  1. Comparison of shrinkage related properties of various patch repair materials

    Science.gov (United States)

    Kristiawan, S. A.; Fitrianto, R. S.

    2017-02-01

    A patch repair material has been developed in the form of unsaturated polyester resin (UPR)-mortar. The performance and durability of this material are governed by its compatibility with the concrete being repaired. One of the compatibility issue that should be tackled is the dimensional compatibility as a result of differential shrinkage between the repair material and the concrete substrate. This research aims to evaluate such shrinkage related properties of UPR-mortar and to compare with those of other patch repair materials. The investigation includes the following aspects: free shrinkage, resistance to delamination and cracking. The results indicate that UPR-mortar poses a lower free shrinkage, lower risk of both delamination and cracking tendency in comparison to other repair materials.

  2. Service water system repair/replacement guidelines: Planning and implementation

    International Nuclear Information System (INIS)

    Frederick, G.J.; Gandy, D.W.; Peterson, A.G. Jr.; Findlan, S.J.

    1993-11-01

    Service water system failures have prompted concerns related to extended power plant operating life and plant availability. Selection and procurement of materials for repair or replacement of piping and components may be the most important factors in improving service water system reliability. The authors examined factors that contribute to reduced SWS reliability. The factors include material selection inadequacies, water treatment problems, operational/maintenance practices, fabrication procedures, environmental degradation mechanisms, and coating problems. The authors investigated material selection for replacement and repair, taking into account fabrication practices, environmental concerns, and cost comparisons of materials. They examined specific components such as piping, pumps, valves, and heat exchangers with regard to material selection and fabrication practice. Although proper material selection is essential in upgrading and maintaining the designed functions of a SWS, it is critical to address SWS repair/replacement activities with a systemwide approach. Degradation of materials in SWS applications are plant specific, depending on factors unique to each site such as geographic location, existing materials, operating procedures, and environment. All these characteristics must be addressed in making repair/replacement decisions. Criteria that must be integrated for successful long-term operation of SWS include the following: Materials selection (upgrade or in-kind replacement), Evaluation of root cause or nature of the failure mechanism, Scope of the repair/replacement activities, Material compatibility of the existing materials, Operational and maintenance procedures, Code or jurisdictional requirements, Economic considerations, Water treatment programs, System design improvements or modifications

  3. Material Systems

    DEFF Research Database (Denmark)

    Jensen, Mads Brath; Mortensen, Henrik Rubæk; Mullins, Michael

    2009-01-01

    This paper describes and reflects upon the results of an investigative project which explores the setting up of a material system - a parametric and generative assembly consisting of and taking into consideration material properties, manufacturing constraints and geometric behavior. The project...... approaches the subject through the construction of a logic-driven system aiming to explore the possibilities of a material system that fulfills spatial, structural and performative requirements concurrently and how these are negotiated in situations where they might be conflicting....

  4. Comparison of the Osteogenic Potential of Mineral Trioxide Aggregate and Endosequence Root Repair Material in a 3-dimensional Culture System.

    Science.gov (United States)

    Rifaey, Hisham S; Villa, Max; Zhu, Qiang; Wang, Yu-Hsiung; Safavi, Kamran; Chen, I-Ping

    2016-05-01

    The ability to promote osteoblast differentiation is a desirable property of root-end filling materials. Several in vitro studies compare the cytotoxicity and physical properties between mineral trioxide aggregate (MTA) and Endosequence root repair material (ERRM), but not their osteogenic potential. Three-dimensional cultures allow cells to better maintain their physiological morphology and better resemble in vivo cellular response than 2-dimensional cultures. Here we examined the osteogenic potential of MTA and ERRM by using a commercially available 3-dimensional Alvetex scaffold. Mandibular osteoblasts were derived from 3-week-old male transgenic reporter mice where mature osteoblasts express green fluorescent protein (GFP) driven by a 2.3-kilobase type I collagen promoter (Col(I)-2.3). Mandibular osteoblasts were grown on Alvetex in direct contact with MTA, ERRM, or no material (negative control) for 14 days. Osteoblast differentiation was evaluated by expression levels of osteogenic genes by using quantitative polymerase chain reaction and by the spatial dynamics of Col(I)-2.3 GFP-positive mature osteoblasts within the Alvetex scaffolds by using 2-photon microscopy. ERRM significantly increased alkaline phosphatase (Alp) and bone sialoprotein (Bsp) expression compared with MTA and negative control groups. Both MTA and ERRM increased osterix (Osx) mRNA significantly compared with the negative control group. The percentage of Col(I)-2.3 GFP-positive cells over total cells within Alvetex was the highest in the ERRM group, followed by MTA and by negative controls. ERRM promotes osteoblast differentiation better than MTA and controls with no material in a 3-dimensional culture system. Alvetex scaffolds can be used to test endodontic materials. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. Moisture movement in cement-based repair systems monitored by X-ray absorption

    NARCIS (Netherlands)

    Lukovic, M.; Ye, G.; Schlangen, H.E.J.G.; van Breugel, K.

    2017-01-01

    In concrete repair systems, material properties in the repair material and interface are greatly influenced by the initial moisture content of the concrete (or mortar) substrate. In order to quantify moisture profiles inside the repair system, X-ray absorption was used. Preliminary studies are

  6. Biodegradable Magnesium Alloys Developed as Bone Repair Materials: A Review

    Directory of Open Access Journals (Sweden)

    Chen Liu

    2018-01-01

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

  7. Using repair priorities in systems with redundacies

    NARCIS (Netherlands)

    Sleptchenko, A.V.; Adan, I.J.B.F.; Van Houtum, G.-J.

    2014-01-01

    In this paper, we present and analyze a mathematical model for the computation of the system availability for a system of parallel machines with redundancies and repair priorities. Using the presented models, we show that the repair priorities have a strong effect on the performance of the system.

  8. Stochastic Modelling Of The Repairable System

    Directory of Open Access Journals (Sweden)

    Andrzejczak Karol

    2015-11-01

    Full Text Available All reliability models consisting of random time factors form stochastic processes. In this paper we recall the definitions of the most common point processes which are used for modelling of repairable systems. Particularly this paper presents stochastic processes as examples of reliability systems for the support of the maintenance related decisions. We consider the simplest one-unit system with a negligible repair or replacement time, i.e., the unit is operating and is repaired or replaced at failure, where the time required for repair and replacement is negligible. When the repair or replacement is completed, the unit becomes as good as new and resumes operation. The stochastic modelling of recoverable systems constitutes an excellent method of supporting maintenance related decision-making processes and enables their more rational use.

  9. RESTORING A DAMAGED 16-YEAR -OLD INSULATING POLYMER CONCRETE DIKE OVERLAY: REPAIR MATERIALS AND TECHNOLOGIES.

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA,T.

    2007-01-01

    The objective of this program was to design and formulate organic polymer-based material systems suitable for repairing and restoring the overlay panels of insulating lightweight polymer concrete (ILPC) from the concrete floor and slope wall of a dike at KeySpan liquefied natural gas (LNG) facility in Greenpoint, Brooklyn, NY, just over sixteen years ago. It also included undertaking a small-scale field demonstration to ensure that the commercial repairing technologies were applicable to the designed and formulated materials.

  10. Diverless pipeline repair system for deep water

    Energy Technology Data Exchange (ETDEWEB)

    Spinelli, Carlo M. [Eni Gas and Power, Milan (Italy); Fabbri, Sergio; Bachetta, Giuseppe [Saipem/SES, Venice (Italy)

    2009-07-01

    SiRCoS (Sistema Riparazione Condotte Sottomarine) is a diverless pipeline repair system composed of a suite of tools to perform a reliable subsea pipeline repair intervention in deep and ultra deep water which has been on the ground of the long lasting experience of Eni and Saipem in designing, laying and operating deep water pipelines. The key element of SiRCoS is a Connection System comprising two end connectors and a repair spool piece to replace a damaged pipeline section. A Repair Clamp with elastomeric seals is also available for pipe local damages. The Connection System is based on pipe cold forging process, consisting in swaging the pipe inside connectors with suitable profile, by using high pressure seawater. Three swaging operations have to be performed to replace the damaged pipe length. This technology has been developed through extensive theoretical work and laboratory testing, ending in a Type Approval by DNV over pipe sizes ranging from 20 inches to 48 inches OD. A complete SiRCoS system has been realised for the Green Stream pipeline, thoroughly tested in workshop as well as in shallow water and is now ready, in the event of an emergency situation.The key functional requirements for the system are: diverless repair intervention and fully piggability after repair. Eni owns this technology and is now available to other operators under Repair Club arrangement providing stand-by repair services carried out by Saipem Energy Services. The paper gives a description of the main features of the Repair System as well as an insight into the technological developments on pipe cold forging reliability and long term duration evaluation. (author)

  11. Regression Models for Repairable Systems

    Czech Academy of Sciences Publication Activity Database

    Novák, Petr

    2015-01-01

    Roč. 17, č. 4 (2015), s. 963-972 ISSN 1387-5841 Institutional support: RVO:67985556 Keywords : Reliability analysis * Repair models * Regression Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.782, year: 2015 http://library.utia.cas.cz/separaty/2015/SI/novak-0450902.pdf

  12. Assessment of repair welding technologies of irradiated materials

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-15

    Damages on reactor internals of stainless steels caused by stress corrosion cracking and fatigue were identified in aged BWR plants. Repair-welding is one of the practical countermeasure candidates to restore the soundness of components and structures. The project of 'Assessment of Repair welding Technologies of Irradiated Materials' has been carried out to develop the technical guideline regarding the repair-welding of reactor internals. In FY 2011, we investigated the fatigue strength of stainless steel SUS316L irradiated by YAG laser welding. Furthermore, revision of the technical guideline regarding the repair-welding of reactor internals was discussed. Diagram of tungsten inert gas (TIG) weld cracking caused by entrapped Helium was modified. Helium concentration for evaluation-free of TIG weld cracking caused by entrapped Helium was revised to 0.007appm from 0.01appm. (author)

  13. Repair-welding technology of irradiated materials - WIM project

    International Nuclear Information System (INIS)

    Nakata, K.; Oishi, M.

    1998-01-01

    A new project on the development of repair-welding technology for core internals and reactor (pressure) vessel, consigned by the Ministry of International Trade and Industry (MITI), has been started from October 1997. The objective of the project is classified into three points as follows: (1) to develop repair-welding techniques for neutron irradiated materials, (2) to prove the availability of the techniques for core internals and reactor (pressure) vessel, and (3) to recommend the updated repair-welding for the Technical Rules and Standards. Total planning, neutron irradiation, preparation of welding equipment are now in progress. The materials are austenitic stainless steels and a low alloy steel. Neutron irradiation is performed using test reactors. In order to suppress the helium aggregation along grain boundaries, low heat input welding techniques, such as laser, low heat input TIG and friction weldings, will be applied. (author)

  14. Thermal segregation of asphalt material in road repair

    Directory of Open Access Journals (Sweden)

    Juliana Byzyka

    2017-08-01

    Full Text Available This paper presents results from a field study of asphaltic pavement patching operations performed by three different contractors working in a total of ten sites. It forms part of an ongoing research programme towards improving the performance of pothole repairs. Thermal imaging technology was used to record temperatures of the patching material throughout the entire exercise, from the stage of material collection, through transportation to repair site, patch forming, and compaction. Practical complications occurring during patch repairs were also identified. It was found that depending on the weather conditions, duration of the travel and poor insulation of the transported hot asphalt mix, its temperature can drop as high as 116.6 °C over the period that the reinstatement team travel to the site and prepare the patch. This impacting is on the durability and performance of the executed repairs. Cold spots on the asphalt mat and temperature differentials between the new hot-fill asphalt mix and existing pavement were also identified as poorly compacted areas that were prone to premature failure. For example, over the five-minute period, the temperature at one point reduced by 33% whereas the temperatures of nearby areas decreased by 65% and 71%. A return visit to the repair sites, three months later, revealed that locations where thermal segregation was noted, during the patching operation, had failed prematurely.

  15. Skull repair materials applied in cranioplasty: History and progress

    Institute of Scientific and Technical Information of China (English)

    Qingsheng Yu; Lin Chen; Zhiye Qiu; Yuqi Zhang; Tianxi Song; Fuzhai Cui

    2017-01-01

    The skull provides protection and mechanical support, and acts as a container for the brain and its accessory organs. Some defects in the skull can fatally threaten human life. Many efforts have been taken to repair defects in the skull, among which cranioplasty is the most prominent technique. To repair the injury, numerous natural and artificial materials have been adopted by neurosurgeons. Many cranioprostheses have been tried in the past decades, from autoplast to bioceramics. Neurosurgeons have been evaluating their advantages andshortages through clinical practice. Among those prostheses, surgeons gradually prefer bionic ones due to their marvelous osteoconductivity, osteoinductivity, biocompatibility,and biodegradability. Autogeneic bone has been widely recognized as the"gold standard" for renovating large-sized bone defects. However, the access to this technique is restricted by limited availability and complications associated with its use. Many metal and polymeric materials with mechanical characteristics analogous to natural bones were consequently applied to cranioplasty. But most of them were unsatisfactory concerning osteoconductiion and biodegradability owe to their intrinsic properties. With the microstructures almost identical to natural bones, mineralized collagen hasbiological performance nearly identical to autogeneic bone, such as osteoconduction. Implants made of mineralized collagen can integrate themselves into the newly formed bones through a process called"creeping substitution". In this review, the authors retrospect the evolution of skull repair material applied in cranioplasty. The ultimate skull repair material should have microstructure and bioactive qualities that enable osteogenesis induction and intramembranous ossification.

  16. ADHESIVE SYSTEM AFFECTS REPAIR BOND STRENGTH OF RESIN COMPOSITE

    Directory of Open Access Journals (Sweden)

    Özgür IRMAK

    2017-10-01

    Full Text Available Purpose: This study evaluated the effects of different adhesive systems on repair bond strength of aged resin composites. Materials and Methods: Ninety composite discs were built and half of them were subjected to thermal aging. Aged and non-aged specimens were repaired with resin composite using three different adhesive systems; a two-step self-etch adhesive, a two-step total-etch adhesive and a one-step self-etch adhesive; then they were subjected to shear forces. Data were analyzed statistically. Results: Adhesive type and aging significantly affected the repair bond strengths (p<0.0001. No statistical difference was found in aged composite groups repaired with two-step self- etch or two-step total-etch adhesive. One-step self-etch adhesive showed lower bond strength values in aged composite repair (p<0.0001. Conclusion: In the repair of aged resin composite, two-step self-etch and two-step total-etch adhesives exhibited higher shear bond strength values than that of one-step self-etch adhesive.

  17. Systems with randomly failing repairable components

    DEFF Research Database (Denmark)

    Der Kiureghian, Armen; Ditlevsen, Ove Dalager; Song, Junho

    2005-01-01

    Closed-form expressions are derived for the steady-state availability, mean rate of failure, mean duration of downtime and reliability of a general system with randomly and independently failing repairable components. Component failures are assumed to be homogeneous Poisson events in time and rep...

  18. DNA repair protocols: prokaryotic systems

    National Research Council Canada - National Science Library

    Vaughan, Patrick

    2000-01-01

    .... All authored papers, comments, opinions, conclusions, or recommendations are those of the author(s), and do not necessarily reflect the views of the publisher. This publication is printed on acid-free paper. ANSI Z39.48-1984 (American Standards Institute) Permanence of Paper for Printed Library Materials. ∞ Cover design by Patricia F. Cleary. For addi...

  19. A model system for DNA repair studies

    International Nuclear Information System (INIS)

    Lange, C.S.; Perlmutter, E.

    1984-01-01

    The search for the ''lethal lesion:'' which would yield a molecular explanation of biological survival curves led to attempts to correlate unrepaired DNA lesions with loss of reproductive integrity. Such studies have shown the crucial importance of DNA repair systems. The unrepaired DSB has been sought for such correlation, but in such study the DNA was too large, polydisperse, and/or structurally complex to permit precise measurement of break induction and repair. Therefore, an analog of higher order systems but with a genome of readily measurable size, is needed. Bacteriophage T4 is such an analog. Both its biological (PFU) and molecular (DNA) survival curves are exponentials. Its aerobic /sub PFU/D/sub 37///sub DNA/D/sub 37/ ratio, (410 +- 4.5Gy/540 +- 25 Gy) indicates that 76 +- 4% of lethality at low multiplicity infection (moi 1) the survival is greater than can be explained if the assumption of no parental DSB repair were valid. Both T4 and its host have DSB repair systems which can be studied by the infectious center method. Results of such studies are discussed

  20. Method of tissue repair using a composite material

    Energy Technology Data Exchange (ETDEWEB)

    Hutchens, Stacy A.; Woodward, Jonathan; Evans, Barbara R.; O' Neill, Hugh M.

    2016-03-01

    A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

  1. Method of tissue repair using a composite material

    Science.gov (United States)

    Hutchens, Stacy A; Woodward, Jonathan; Evans, Barbara R; O'Neill, Hugh M

    2014-03-18

    A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

  2. Design of self-growing, self-sensing, and self-repairing materials for engineering applications

    Science.gov (United States)

    Dry, Carolyn M.

    2001-04-01

    Like natural biological building systems these materials are inexpensive, and self-form through interaction of the materials. They sense and self-repair, respond to changes in the environment. The volume and scale, cost and end use are all considered from the start. The purpose of the particular system we will describe is an engineered bridge. The materials form as bone does from the innate attributes of the material without much labor. They sense the environment, respond to it, and repair any damage. This composite bridge is designed from a self-forming polymer and concrete system. Internal release of chemicals, their properties and location account for responsiveness to change and for repair. The choice of matrix additives also allow for the responsiveness. Bridge frames were fabricated for dynamic testing. The results showed that self repair and response to loads could be accomplished by careful placement of chemicals for later release and by use of chemicals which could alter such attributes as stiffness, flexure and permanent deformation. Internal viewing sensors could determine the state of the frames after testing.

  3. Assessment of repair welding technologies of irradiated materials

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-08-15

    Damages of reactor internals of stainless steels caused by SCC and fatigue were identified in aged BWR plants. Repair-welding is one of the practical countermeasure candidates to restore the soundness of components and structures. The project of 'Assessment of Repair welding Technologies of Irradiated Materials' is being carried out to develop the technical guideline regarding the repair-welding of reactor internals. In fiscal 2011, we investigated the weldability of stainless steel 316L irradiated by welding (TIG) tungsten inert gas. Furthermore, the tensile properties and stress corrosion cracking (SCC) susceptibility of the welds were investigated. Cross-sectional observation of heat affected zone (HAZ) of the bead on plate TIG weldments (heat input 4 kJ/cm) of irradiated SUS316L stainless steel containing 0.026 ~ 0.12appm helium showed degradation of grain boundaries due to helium accumulation. Degree of the degradation depended on the amount of helium. No deterioration of grain boundaries was observed by bead on plate welding with one pass one layer when helium content was 0.039appm. The tensile strengths of welds in non-irradiated and irradiated material were similar. However, the elongation of a weldment by irradiated SUS316L containing 0.124appm Helium was lower than non-irradiated. It was estimated to cause the effects of helium bubbles. The SCC susceptibility of the HAZ was no significant difference compared with other locations. (author)

  4. Morphologic study of three collagen materials for body wall repair.

    Science.gov (United States)

    Soiderer, Emily E; Lantz, Gary C; Kazacos, Evelyn A; Hodde, Jason P; Wiegand, Ryan E

    2004-05-15

    The search for ideal prostheses for body wall repair continues. Synthetic materials such as polypropylene mesh (PPM) are associated with healing complications. A porcine-derived collagen-based material (CBM), small intestinal submucosa (SIS), has been studied for body wall repair. Renal capsule matrix (RCM) and urinary bladder submucosa (UBS) are CBMs not previously evaluated in this application. This is the first implant study using RCM. Full-thickness muscle/fascia ventral abdominal wall defects were repaired with SIS, RCM, UBS, and PPM in rats with omentum and omentectomy. A random complete block design was used to allot implant type to each of 96 rats. Healing was evaluated at 4 and 8 weeks. Adhesion tenacity and surface area were scored. Implant site dimensions were measured at implantation and necropsy. Inflammation, vascularization, and fibrosis were histopathologically scored. Data were compared by analysis of variance (P response in contrast to the organized healing of CBM implants. CBM mean scores were lower than PPM scores for adhesion tenacity, surface area, and inflammation at each follow-up time for rats with omentums (P fibrotic response to PPM was unique and more intense compared to CBMs. These CBM implants appear morphologically acceptable and warrant continued investigation.

  5. A geometric process repair model for a repairable cold standby system with priority in use and repair

    International Nuclear Information System (INIS)

    Zhang Yuanlin; Wang Guanjun

    2009-01-01

    In this paper, a deteriorating cold standby repairable system consisting of two dissimilar components and one repairman is studied. For each component, assume that the successive working times form a decreasing geometric process while the consecutive repair times constitute an increasing geometric process, and component 1 has priority in use and repair. Under these assumptions, we consider a replacement policy N based on the number of repairs of component 1 under which the system is replaced when the number of repairs of component 1 reaches N. Our problem is to determine an optimal policy N* such that the average cost rate (i.e. the long-run average cost per unit time) of the system is minimized. The explicit equation of the average cost rate of the system is derived and the corresponding optimal replacement policy N* can be determined analytically or numerically. Finally, a numerical example with Weibull distribution is given to illustrate some theoretical results in this paper.

  6. Analysis for a two-dissimilar-component cold standby repairable system with repair priority

    International Nuclear Information System (INIS)

    Leung, Kit Nam Francis; Zhang Yuanlin; Lai, Kin Keung

    2011-01-01

    In this paper, a cold standby repairable system consisting of two dissimilar components and one repairman is studied. Assume that working time distributions and repair time distributions of the two components are both exponential, and Component 1 has repair priority when both components are broken down. After repair, Component 1 follows a geometric process repair while Component 2 obeys a perfect repair. Under these assumptions, using the perfect repair model, the geometric process repair model and the supplementary variable technique, we not only study some important reliability indices, but also consider a replacement policy T, under which the system is replaced when the working age of Component 1 reaches T. Our problem is to determine an optimal policy T* such that the long-run average loss per unit time (i.e. average loss rate) of the system is minimized. The explicit expression for the average loss rate of the system is derived, and the corresponding optimal replacement policy T* can be found numerically. Finally, a numerical example for replacement policy T is given to illustrate some theoretical results and the model's applicability. - Highlights: → A two-dissimilar-component cold standby system with repair priority is formulated. → The successive up/repair times of Component 1 form a decreasing/increasing geometric process. → Not only some reliability indices but also a replacement policy are studied.

  7. In-Space Repair and Refurbishment of Thermal Protection System Structures for Reusable Launch Vehicles

    Science.gov (United States)

    Singh, M.

    2007-01-01

    Advanced repair and refurbishment technologies are critically needed for the thermal protection system of current space transportation systems as well as for future launch and crew return vehicles. There is a history of damage to these systems from impact during ground handling or ice during launch. In addition, there exists the potential for in-orbit damage from micrometeoroid and orbital debris impact as well as different factors (weather, launch acoustics, shearing, etc.) during launch and re-entry. The GRC developed GRABER (Glenn Refractory Adhesive for Bonding and Exterior Repair) material has shown multiuse capability for repair of small cracks and damage in reinforced carbon-carbon (RCC) material. The concept consists of preparing an adhesive paste of desired ceramic with appropriate additives and then applying the paste to the damaged/cracked area of the RCC composites with an adhesive delivery system. The adhesive paste cures at 100-120 C and transforms into a high temperature ceramic during reentry conditions. A number of plasma torch and ArcJet tests were carried out to evaluate the crack repair capability of GRABER materials for Reinforced Carbon-Carbon (RCC) composites. For the large area repair applications, Integrated Systems for Tile and Leading Edge Repair (InSTALER) have been developed and evaluated under various ArcJet testing conditions. In this presentation, performance of the repair materials as applied to RCC is discussed. Additionally, critical in-space repair needs and technical challenges are reviewed.

  8. In-Space Repair of Reinforced Carbon-Carbon Thermal Protection System Structures

    Science.gov (United States)

    Singh, Mrityunjay

    2006-01-01

    Advanced repair and refurbishment technologies are critically needed for the thermal protection system of current space transportation system as well as for future Crew Exploration Vehicles (CEV). The damage to these components could be caused by impact during ground handling or due to falling of ice or other objects during launch. In addition, in-orbit damage includes micrometeoroid and orbital debris impact as well as different factors (weather, launch acoustics, shearing, etc.) during launch and re-entry. The GRC developed GRABER (Glenn Refractory Adhesive for Bonding and Exterior Repair) material has shown multiuse capability for repair of small cracks and damage in reinforced carbon-carbon (RCC) material. The concept consists of preparing an adhesive paste of desired ceramic with appropriate additives and then applying the paste to the damaged/cracked area of the RCC composites with adhesive delivery system. The adhesive paste cures at 100-120 C and transforms into a high temperature ceramic during simulated entry conditions. A number of plasma torch and ArcJet tests were carried out to evaluate the crack repair capability of GRABER materials for Reinforced Carbon-Carbon (RCC) composites. For the large area repair applications, integrated system for tile and leading edge repair (InSTALER) have been developed. In this presentation, critical in-space repair needs and technical challenges as well as various issues and complexities will be discussed along with the plasma performance and post test characterization of repaired RCC materials.

  9. A modelling study of drying shrinkage damage in concrete repair systems

    NARCIS (Netherlands)

    Lukovic, M.; Savija, B.; Schlangen, E.; Ye, G.; van Breugel, K.

    2014-01-01

    Differential shrinkage between repair material and concrete substrate is considered to be the main cause of premature failure of repair systems (Martinola, Sadouki et al. 2001, Beushausen and Alexander 2007). Magnitude of induced stresses depends on many factors, for example the amount of restraint,

  10. A 3D Lattice Modelling Study of Drying Shrinkage Damage in Concrete Repair Systems

    NARCIS (Netherlands)

    Lukovic, M.; Savija, B.; Schlangen, H.E.J.G.; Ye, G.; van Breugel, K.

    2016-01-01

    Differential shrinkage between repair material and concrete substrate is considered to be the main cause of premature failure of repair systems. The magnitude of induced stresses depends on many factors, for example the degree of restraint, moisture gradients caused by curing and drying conditions,

  11. ANALYTICAL MODEL OF DAMAGED AIRCRAFT SKIN BONDED REPAIRS ASSUMING THE MATERIAL PROPERTIES DEGRADATION

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available The search of optimal variants for composite repair patches allows to increase the service life of a damaged air- plane structure. To sensibly choose the way of repair, it is necessary to have a computational complex to predict the stress- strain condition of "structure-adhesive-patch" system and to take into account the damage growth considering the material properties change. The variant of the computational complex based on inclusion method is proposed.For calculation purposes the repair bonded joint is divided into two areas: a metal plate with patch-shaped hole and a "patch-adhesive layer-skin" composite plate (inclusion.Calculation stages:Evaluation of the patch influence to the skin stress-strain condition, stress distribution between skin and patch in the case of no damage. Calculation of the stress-strain condition is performed separately for the skin with hole and for the inclusion; solutions are coupled based on strain compatibility.Definition of the damage growth parameters at new stress-strain condition due to bonded patch existence. Skincrack stress intensity factors are found to identify the crack growth velocity. Patch is modelled as a set of "springs" bridging the crack.Degradation analysis of elasticity properties for the patch material.Repair effectiveness is evaluated with respect to crack growth velocity reduction in the initial material in compari- son with the case of the patch absence.Calculation example for the crack repair effectiveness depending on number of loading cycles for the 7075-T6 aluminum skin is given. Repair patches are carbon-epoxy, glass-epoxy and boron-epoxy material systems with quasi- isotropic layup and GLARE hybrid metal-polymeric material.The analysis shows the high effectiveness of the carbon-epoxy patch. Due to low stiffness, the glass-epoxy patchdemonstrates the least effectiveness. GLARE patch containing the fiberglass plies oriented across the crack has the same effectiveness as the carbon and

  12. A 3D Lattice Modelling Study of Drying Shrinkage Damage in Concrete Repair Systems

    Directory of Open Access Journals (Sweden)

    Mladena Luković

    2016-07-01

    Full Text Available Differential shrinkage between repair material and concrete substrate is considered to be the main cause of premature failure of repair systems. The magnitude of induced stresses depends on many factors, for example the degree of restraint, moisture gradients caused by curing and drying conditions, type of repair material, etc. Numerical simulations combined with experimental observations can be of great use when determining the influence of these parameters on the performance of repair systems. In this work, a lattice type model was used to simulate first the moisture transport inside a repair system and then the resulting damage as a function of time. 3D simulations were performed, and damage patterns were qualitatively verified with experimental results and cracking tendencies in different brittle and ductile materials. The influence of substrate surface preparation, bond strength between the two materials, and thickness of the repair material were investigated. Benefits of using a specially tailored fibre reinforced material, namely strain hardening cementitious composite (SHCC, for controlling the damage development due to drying shrinkage in concrete repairs was also examined.

  13. Space Transportation System (STS)-133/External Tank (ET)-137 Intertank (IT) Stringer Cracking Issue and Repair Assessment: Proximate Cause Determination and Material Characterization Study

    Science.gov (United States)

    Piascik, Robert S.

    2011-01-01

    Several cracks were detected in stringers located beneath the foam on the External Tank (ET) following the launch scrub of Space Transportation System (STS)-133 on November 5, 2010. The stringer material was aluminum-lithium (AL-Li) 2090-T83 fabricated from sheets that were nominally 0.064 inches thick. The mechanical properties of the stringer material were known to vary between different material lots, with the stringers from ET-137 (predominately lots 620853 and 620854) having the highest yield and ultimate stresses. Subsequent testing determined that these same lots also had the lowest fracture toughness properties. The NASA Engineering and Safety Center (NESC) supported the Space Shuttle Program (SSP)-led investigation. The objective of this investigation was to develop a database of test results to provide validation for structural analysis models, independently confirm test results obtained from other investigators, and determine the proximate cause of the anomalous low fracture toughness observed in stringer lots 620853 and 620854. This document contains the outcome of the investigation.

  14. Finite-Element Modeling of a Damaged Pipeline Repaired Using the Wrap of a Composite Material

    Science.gov (United States)

    Lyapin, A. A.; Chebakov, M. I.; Dumitrescu, A.; Zecheru, G.

    2015-07-01

    The nonlinear static problem of FEM modeling of a damaged pipeline repaired by a composite material and subjected to internal pressure is considered. The calculation is carried out using plasticity theory for the pipeline material and considering the polymeric filler and the composite wrap. The level of stresses in various zones of the structure is analyzed. The most widespread alloy used for oil pipelines is selected as pipe material. The contribution of each component of the pipeline-filler-wrap system to the level of stresses is investigated. The effect of the number of composite wrap layers is estimated. The results obtained allow one to decrease the costs needed for producing test specimens.

  15. Effect of Moisture Exchange on Interface Formation in the Repair System Studied by X-ray Absorption

    Directory of Open Access Journals (Sweden)

    Mladena Lukovic

    2015-12-01

    Full Text Available In concrete repair systems, material properties of the repair material and the interface are greatly influenced by the moisture exchange between the repair material and the substrate. If the substrate is dry, it can absorb water from the repair material and reduce its effective water-to-cement ratio (w/c. This further affects the hydration rate of cement based material. In addition to the change in hydration rate, void content at the interface between the two materials is also affected. In this research, the influence of moisture exchange on the void content in the repair system as a function of initial saturation level of the substrate is investigated. Repair systems with varying level of substrate saturation are made. Moisture exchange in these repair systems as a function of time is monitored by the X-ray absorption technique. After a specified curing age (3 d, the internal microstructure of the repair systems was captured by micro-computed X-ray tomography (CT-scanning. From reconstructed images, different phases in the repair system (repair material, substrate, voids can be distinguished. In order to quantify the void content, voids were thresholded and their percentage was calculated. It was found that significantly more voids form when the substrate is dry prior to application of the repair material. Air, initially filling voids and pores of the dry substrate, is being released due to the moisture exchange. As a result, air voids remain entrapped in the repair material close to the interface. These voids are found to form as a continuation of pre-existing surface voids in the substrate. Knowledge about moisture exchange and its effects provides engineers with the basis for recommendations about substrate preconditioning in practice.

  16. Effect of Moisture Exchange on Interface Formation in the Repair System Studied by X-ray Absorption.

    Science.gov (United States)

    Lukovic, Mladena; Ye, Guang

    2015-12-22

    In concrete repair systems, material properties of the repair material and the interface are greatly influenced by the moisture exchange between the repair material and the substrate. If the substrate is dry, it can absorb water from the repair material and reduce its effective water-to-cement ratio (w/c). This further affects the hydration rate of cement based material. In addition to the change in hydration rate, void content at the interface between the two materials is also affected. In this research, the influence of moisture exchange on the void content in the repair system as a function of initial saturation level of the substrate is investigated. Repair systems with varying level of substrate saturation are made. Moisture exchange in these repair systems as a function of time is monitored by the X-ray absorption technique. After a specified curing age (3 d), the internal microstructure of the repair systems was captured by micro-computed X-ray tomography (CT-scanning). From reconstructed images, different phases in the repair system (repair material, substrate, voids) can be distinguished. In order to quantify the void content, voids were thresholded and their percentage was calculated. It was found that significantly more voids form when the substrate is dry prior to application of the repair material. Air, initially filling voids and pores of the dry substrate, is being released due to the moisture exchange. As a result, air voids remain entrapped in the repair material close to the interface. These voids are found to form as a continuation of pre-existing surface voids in the substrate. Knowledge about moisture exchange and its effects provides engineers with the basis for recommendations about substrate preconditioning in practice.

  17. Artificial-Crack-Behavior Test Evaluation of the Water-Leakage Repair Materials Used for the Repair of Water-Leakage Cracks in Concrete Structures

    OpenAIRE

    Soo-Yeon Kim; Sang-Keun Oh; Byoungil Kim

    2016-01-01

    There are no existing standard test methods at home and abroad that can verify the performance of water leakage repair materials, and it is thus very difficult to perform quality control checks in the field of water leakage repair. This study determined that the key factors that have the greatest impact on the water leakage repair materials are the micro-behaviors of cracks, and proposed an artificial-crack-behavior test method for the performance verification of the repair materials. The per...

  18. Piezoelectric materials as stimulatory biomedical materials and scaffolds for bone repair.

    Science.gov (United States)

    Tandon, Biranche; Blaker, Jonny J; Cartmell, Sarah H

    2018-04-16

    The process of bone repair and regeneration requires multiple physiological cues including biochemical, electrical and mechanical - that act together to ensure functional recovery. Myriad materials have been explored as bioactive scaffolds to deliver these cues locally to the damage site, amongst these piezoelectric materials have demonstrated significant potential for tissue engineering and regeneration, especially for bone repair. Piezoelectric materials have been widely explored for power generation and harvesting, structural health monitoring, and use in biomedical devices. They have the ability to deform with physiological movements and consequently deliver electrical stimulation to cells or damaged tissue without the need of an external power source. Bone itself is piezoelectric and the charges/potentials it generates in response to mechanical activity are capable of enhancing bone growth. Piezoelectric materials are capable of stimulating the physiological electrical microenvironment, and can play a vital role to stimulate regeneration and repair. This review gives an overview of the association of piezoelectric effect with bone repair, and focuses on state-of-the-art piezoelectric materials (polymers, ceramics and their composites), the fabrication routes to produce piezoelectric scaffolds, and their application in bone repair. Important characteristics of these materials from the perspective of bone tissue engineering are highlighted. Promising upcoming strategies and new piezoelectric materials for this application are presented. Electrical stimulation/electrical microenvironment are known effect the process of bone regeneration by altering the cellular response and are crucial in maintaining tissue functionality. Piezoelectric materials, owing to their capability of generating charges/potentials in response to mechanical deformations, have displayed great potential for fabricating smart stimulatory scaffolds for bone tissue engineering. The growing

  19. A biocompatible hybrid material with simultaneous calcium and strontium release capability for bone tissue repair

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, J. Carlos [CICECO — Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro (Portugal); Wacha, András [Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar Tudósok körútja 2, Budapest 1117 (Hungary); Gomes, Pedro S. [Laboratory for Bone Metabolism and Regeneration, Faculdade de Medicina Dentária, Universidade do Porto (Portugal); Alves, Luís C. [C2TN, Instituto Superior Técnico, Universidade de Lisboa, E.N.10, 2695-066 Bobadela LRS (Portugal); Fernandes, M. Helena Vaz [CICECO — Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro (Portugal); Salvado, Isabel M. Miranda, E-mail: isabelmsalvado@ua.pt [CICECO — Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro (Portugal); Fernandes, M. Helena R. [Laboratory for Bone Metabolism and Regeneration, Faculdade de Medicina Dentária, Universidade do Porto (Portugal)

    2016-05-01

    The increasing interest in the effect of strontium in bone tissue repair has promoted the development of bioactive materials with strontium release capability. According to literature, hybrid materials based on the system PDMS–SiO{sub 2} have been considered a plausible alternative as they present a mechanical behavior similar to the one of the human bone. The main purpose of this study was to obtain a biocompatible hybrid material with simultaneous calcium and strontium release capability. A hybrid material, in the system PDMS–SiO{sub 2}–CaO–SrO, was prepared with the incorporation of 0.05 mol of titanium per mol of SiO{sub 2}. Calcium and strontium were added using the respective acetates as sources, following a sol–gel technique previously developed by the present authors. The obtained samples were characterized by FT-IR, solid-state NMR, and SAXS, and surface roughness was analyzed by 3D optical profilometry. In vitro studies were performed by immersion of the samples in Kokubo's SBF for different periods of time, in order to determine the bioactive potential of these hybrids. Surfaces of the immersed samples were observed by SEM, EDS and PIXE, showing the formation of calcium phosphate precipitates. Supernatants were analyzed by ICP, revealing the capability of the material to simultaneously fix phosphorus ions and to release calcium and strontium, in a concentration range within the values reported as suitable for the induction of the bone tissue repair. The material demonstrated to be cytocompatible when tested with MG63 osteoblastic cells, exhibiting an inductive effect on cell proliferation and alkaline phosphatase activity. - Highlights: • A hybrid PDMS–SiO{sub 2}–CaO–SrO material was prepared with the incorporation of Ti. • Sr was released in concentrations suitable for the induction of bone tissue repair. • The material demonstrated to be cytocompatible when tested with osteoblastic cells.

  20. Two intelligent materials, both of which are self-forming and self-repairing; one also self-senses and recycles

    Science.gov (United States)

    Dry, Carolyn M.

    1996-04-01

    Two self-forming and repair polymer cementitious composites were developed over a decade apart by the author. Both relied on a nature based paradigm as a model for building, in particular bone formation, repair, and degradation. For the first composite, the proposed material accreted from the ocean, made from a fluids based chemistry, that of seawater. The land based system was not built in-situ but relied on a man made supply of materials which were self-forming, self-repairing and dissolving. But in both cases a fluid based chemistry was necessary for self-building, repair and recycling of a bone-like composite material.

  1. Development of implants composed of bioactive materials for bone repair

    Science.gov (United States)

    Xiao, Wei

    The purpose of this Ph.D. research was to address the clinical need for synthetic bioactive materials to heal defects in non-loaded and loaded bone. Hollow hydroxyapatite (HA) microspheres created in a previous study were evaluated as a carrier for controlled release of bone morphogenetic protein-2 (BMP2) in bone regeneration. New bone formation in rat calvarial defects implanted with BMP2-loaded microspheres (43%) was significantly higher than microspheres without BMP2 (17%) at 6 weeks postimplantation. Then hollow HA microspheres with a carbonate-substituted composition were prepared to improve their resorption rate. Hollow HA microspheres with 12 wt. % of carbonate showed significantly higher new bone formation (73 +/- 8%) and lower residual HA (7 +/- 2%) than stoichiometric HA microspheres (59 +/- 2% new bone formation; 21 +/- 3% residual HA). The combination of carbonate-substituted hollow HA microspheres and clinically-safe doses of BMP2 could provide promising implants for healing non-loaded bone defects. Strong porous scaffolds of bioactive silicate (13-93) glass were designed with the aid of finite-element modeling, created by robocasting and evaluated for loaded bone repair. Scaffolds with a porosity gradient to mimic human cortical bone showed a compressive strength of 88 +/- 20 MPa, a flexural strength of 34 +/- 5 MPa and the ability to support bone infiltration in vivo. The addition of a biodegradable polylactic acid (PLA) layer to the external surface of these scaffolds increased their load-bearing capacity in four-point bending by 50% and dramatically enhanced their work of fracture, resulting in a "ductile" mechanical response. These bioactive glass-PLA composites, combining bioactivity, high strength, high work of fracture and an internal architecture conducive to bone infiltration, could provide optimal implants for structural bone repair.

  2. DNA repair systems as targets of cadmium toxicity

    International Nuclear Information System (INIS)

    Giaginis, Constantinos; Gatzidou, Elisavet; Theocharis, Stamatios

    2006-01-01

    Cadmium (Cd) is a heavy metal and a potent carcinogen implicated in tumor development through occupational and environmental exposure. Recent evidence suggests that proteins participating in the DNA repair systems, especially in excision and mismatch repair, are sensitive targets of Cd toxicity. Cd by interfering and inhibiting these DNA repair processes might contribute to increased risk for tumor formation in humans. In the present review, the information available on the interference of Cd with DNA repair systems and their inhibition is summarized. These actions could possibly explain the indirect contribution of Cd to mutagenic effects and/or carcinogenicity

  3. Mountain Plains Learning Experience Guide: Automotive Repair. Course: Brake Systems.

    Science.gov (United States)

    Schramm, C.; Osland, Walt

    One of twelve individualized courses included in an automotive repair curriculum, this course covers theory, operation, and repair of drum brakes, disc brakes, and brake system components. The course is comprised of six units: (1) Fundamentals of Brake Systems, (2) Master Cylinder, (3) Drum Brakes, (4) Disc Brakes, (5) Power Brakes, and (6)…

  4. Closed loop two-echelon repairable item systems

    NARCIS (Netherlands)

    Spanjers, L.; van Ommeren, Jan C.W.; Zijm, Willem H.M.

    In this paper we consider closed loop two-echelon repairable item systems with repair facilities both at a number of local service centers (called bases) and at a central location (the depot). The goal of the system is to maintain a number of production facilities (one at each base) in optimal

  5. Closed-loop two-echelon repairable item systems

    NARCIS (Netherlands)

    Spanjers, L.; Zijm, Willem H.M.; van Ommeren, Jan C.W.

    2003-01-01

    In this paper we consider closed loop two-echelon repairable item systems with repair facilities both at a number of local service centers (called bases) and at a central location (the depot). The goal of the system is to maintain a number of production facilities (one at each base) in optimal

  6. Reducing costs of repairable inventory supply systems via dynamic scheduling

    NARCIS (Netherlands)

    Tiemessen, H.G.H.; Houtum, van G.J.J.A.N.

    2013-01-01

    We study a system consisting of one repair shop and one stockpoint, where spare parts of multiple critical repairables are kept on stock to serve an installed base of technical systems. Part requests are met from stock if possible, and backordered otherwise. The objective is to minimize aggregate

  7. Component-Level Electronic-Assembly Repair (CLEAR) System Architecture

    Science.gov (United States)

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

    2011-01-01

    This document captures the system architecture for a Component-Level Electronic-Assembly Repair (CLEAR) capability needed for electronics maintenance and repair of the Constellation Program (CxP). CLEAR is intended to improve flight system supportability and reduce the mass of spares required to maintain the electronics of human rated spacecraft on long duration missions. By necessity it allows the crew to make repairs that would otherwise be performed by Earth based repair depots. Because of practical knowledge and skill limitations of small spaceflight crews they must be augmented by Earth based support crews and automated repair equipment. This system architecture covers the complete system from ground-user to flight hardware and flight crew and defines an Earth segment and a Space segment. The Earth Segment involves database management, operational planning, and remote equipment programming and validation processes. The Space Segment involves the automated diagnostic, test and repair equipment required for a complete repair process. This document defines three major subsystems including, tele-operations that links the flight hardware to ground support, highly reconfigurable diagnostics and test instruments, and a CLEAR Repair Apparatus that automates the physical repair process.

  8. Reliable pipeline repair system for very large pipe size

    Energy Technology Data Exchange (ETDEWEB)

    Charalambides, John N.; Sousa, Alexandre Barreto de [Oceaneering International, Inc., Houston, TX (United States)

    2004-07-01

    The oil and gas industry worldwide has been mainly depending on the long-term reliability of rigid pipelines to ensure the transportation of hydrocarbons, crude oil, gas, fuel, etc. Many other methods are also utilized onshore and offshore (e.g. flexible lines, FPSO's, etc.), but when it comes to the underwater transportation of very high volumes of oil and gas, the industry commonly uses large size rigid pipelines (i.e. steel pipes). Oil and gas operators learned to depend on the long-lasting integrity of these very large pipelines and many times they forget or disregard that even steel pipelines degrade over time and more often that that, they are also susceptible to various forms of damage (minor or major, environmental or external, etc.). Over the recent years the industry had recognized the need of implementing an 'emergency repair plan' to account for such unforeseen events and the oil and gas operators have become 'smarter' by being 'pro-active' in order to ensure 'flow assurance'. When we consider very large diameter steel pipelines such as 42' and 48' nominal pipe size (NPS), the industry worldwide does not provide 'ready-made', 'off-the-shelf' repair hardware that can be easily shipped to the offshore location and effect a major repair within acceptable time frames and avoid substantial profit losses due to 'down-time' in production. The typical time required to establish a solid repair system for large pipe diameters could be as long as six or more months (depending on the availability of raw materials). This paper will present in detail the Emergency Pipeline Repair Systems (EPRS) that Oceaneering successfully designed, manufactured, tested and provided to two major oil and gas operators, located in two different continents (Gulf of Mexico, U.S.A. and Arabian Gulf, U.A.E.), for two different very large pipe sizes (42'' and 48'' Nominal Pipe Sizes

  9. Repairing method for reactor primary system pipeline

    International Nuclear Information System (INIS)

    Hosokawa, Hideyuki; Uetake, Naoto; Hara, Teruo.

    1997-01-01

    Pipelines after decontamination of radioactive nuclides deposited on the pipelines in a nuclear power plant during operation or pipelines to replace pipelines deposited with radioactive nuclide are connected to each system of the nuclear power plant. They are heated in a gas phase containing oxygen to form an oxide film on the surface of the pipelines. The thickness of the oxide film formed in the gas phase is 1nm or greater, preferably 100nm. The concentration of oxygen in the gas phase containing oxygen must be 0.1% or greater. The heating is conducted by circulating a heated gas to the inside of the pipelines or disposing a movable heater such as a high frequency induction heater inside of the pipelines to form the oxide film. Then, redeposition of radioactive nuclide can be suppressed and since the oxide film is formed in the gas phase, a large scaled facilities are not necessary, thereby enabling to repair pipelines of reactor primary system at low cost. (N.H.)

  10. Capacitated two-echelon inventory models for repairable item systems

    NARCIS (Netherlands)

    Avsar, Z.M.; Zijm, Willem H.M.; Gershwin, S.B.; Dallery, Y.; Papadopoulos, C.; Smith, J.M.

    2002-01-01

    In this paper, we consider two-echelon maintenance systems with repair facilities both at a number of local service centers (called bases) and at a central location. Each repair facility may be considered to be a job shop and is modeled as a (limited capacity) open queuing network, while any

  11. Analysis of a carbon composite overwrap pipeline repair system

    Energy Technology Data Exchange (ETDEWEB)

    Duell, J.M.; Wilson, J.M. [Department of Mechanical Engineering, University of Tulsa, Tulsa, OK 74104 (United States); Kessler, M.R. [Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011 (United States)], E-mail: mkessler@iastate.edu

    2008-11-15

    A relatively new method has been developed to stop external corrosion and structurally reinforce steel pipes by external wrapping of damaged sections using fibre reinforced polymer (FRP) materials. Several different defect geometries representing corrosion patches on steel pipe were characterized using finite-element analysis, by changing the circumferential length of the defect. Pipe vessels containing these defects along with the composite structural repairs were modeled and the results were compared to field tests to determine the effectiveness of the repairs. It was found that the defect width around the circumference had little impact on the ultimate rupture pressure of the repaired vessel, but influenced the stress state in the underlying pipe substrate.

  12. Application of Interfacial Propagation and Kinking Crack Concept to ECC/Concrete Overlay Repair System

    Directory of Open Access Journals (Sweden)

    Yaw ChiaHwan

    2014-01-01

    Full Text Available Research on the application of ultraductile engineered cementitious composite (ECC as overlay in the repair of deteriorated concrete structures is performed in this paper. Also, interfacial crack kinking and trapping mechanism experimentally observed in ECC/concrete overlay repair system are described by comparison of toughness and energy release rate. The mechanism involves cycles of extension, kinking, and arrest of interfacial crack into the overlay. Experimental testing of overlay repair system reveals significant improvements in load carrying capacity and ductility over conventional concrete overlay. The commonly observed overlay system failure mode of delamination or spalling is eliminated when ECC is applied. These failure modes are suppressed when ECC is used as an ideal and durable candidate overlay repair material.

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

    Science.gov (United States)

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

    2010-12-06

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

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

    Directory of Open Access Journals (Sweden)

    Ser Tong Quek

    2010-12-01

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

  15. A photoactivated nanofiber graft material for augmented Achilles tendon repair.

    Science.gov (United States)

    Ni, Tao; Senthil-Kumar, Prabhu; Dubbin, Karen; Aznar-Cervantes, Salvador D; Datta, Néha; Randolph, Mark A; Cenis, José L; Rutledge, Gregory C; Kochevar, Irene E; Redmond, Robert W

    2012-10-01

    Suture repair of Achilles tendon rupture can cause infection, inflammation and scarring, while prolonged immobilization promotes adhesions to surrounding tissues and joint stiffness. Early mobilization can reduce complications provided the repair is strong enough to resist re-rupture. We have developed a biocompatible, photoactivated tendon wrap from electrospun silk (ES) to provide additional strength to the repair that could permit early mobilization, and act as a barrier to adhesion formation. ES nanofiber mats were prepared by electrospinning. New Zealand white rabbits underwent surgical transection of the Achilles tendon and repair by: (a) SR: standard Kessler suture + epitendinous suture (5-0 vicryl). (b) ES/PTB: a single stay suture and a section of ES mat, stained with 0.1% Rose Bengal (RB), wrapped around the tendon and bonded with 532 nm light (0.3 W/cm(2) , 125 J/cm(2) ). (c) SR + ES/PTB: a combination of (a) and (b). Gross appearance, extent of adhesion formation and biomechanical properties of the repaired tendon were evaluated at Days 7, 14, or 28 post-operatively (n = 8 per group at each time point). Ultimate stress (US) and Young's modulus (E) in the SR group were not significantly different from the ES/PTB group at Days 7 (US, P = 0.85; E, P = 1), 14 (US, P = 0.054; E, P = 1), and 28 (US, P = 0.198; E, P = 0.12) post-operatively. Adhesions were considerably greater in the SR group compared to the ES/PTB group at Days 7 (P = 0.002), 14 (P tendon repair site provides considerable benefit in Achilles tendon repair. Lasers Surg. Med. 44: 645-652, 2012. © 2012 Wiley Periodicals, Inc. Copyright © 2012 Wiley Periodicals, Inc.

  16. Review of Repair Materials for Fire-Damaged Reinforced Concrete Structures

    Science.gov (United States)

    Zahid, MZA Mohd; Abu Bakar, BH; Nazri, FM; Ahmad, MM; Muhamad, K.

    2018-03-01

    Reinforced concrete (RC) structures perform well during fire and may be repaired after the fire incident because their low heat conductivity prevents the loss or degradation of mechanical strength of the concrete core and internal reinforcing steel. When an RC structure is heated to more than 500 °C, mechanical properties such as compressive strength, stiffness, and tensile strength start to degrade and deformations occur. Although the fire-exposed RC structure shows no visible damage, its residual strength decreases compared with that in the pre-fire state. Upon thorough assessment, the fire-damaged RC structure can be repaired or strengthened, instead of subjecting to partial or total demolition followed by reconstruction. The structure can be repaired using several materials, such as carbon fiber-reinforced polymer, glass fiber-reinforced polymer, normal strength concrete, fiber-reinforced concrete, ferrocement, epoxy resin mortar, and high-performance concrete. Selecting an appropriate repair material that must be compatible with the substrate or base material is a vital step to ensure successful repair. This paper reviews existing repair materials and factors affecting their performance. Of the materials considered, ultra-high-performance fiber-reinforced concrete (UHPFRC) exhibits huge potential for repairing fire-damaged RC structures but lack of information available. Hence, further studies must be performed to assess the potential of UHPFRC in rehabilitating fire-damaged RC structures.

  17. Repair systems for deteriorated bridge piles : final report.

    Science.gov (United States)

    2017-04-01

    The objective of this research project is to develop a durable repair system for deteriorated steel bridge piles that : can be implemented without the need for dewatering. A rigorous survey of the relevant practice nationwide was : conducted to infor...

  18. Dacryoscintigraph evaluation of the repaired lacrimal drainage system

    International Nuclear Information System (INIS)

    Hoehn, J.G.; Vitale, P.; Elliott, R.A. Jr.

    1976-01-01

    We have used dacryoscintigraphy to study the efficiency of the lacrimal system following the repair of a divided lower canaliculus in 4 children. This test has been reliable in evaluating lacrimal function and suggests that a canaliculus can be repaired and splinted satisfactorily. Our experience with dacryoscintigraphy confirms that it is a safe comfortable, and reliable method for studying the patency of the lacrimal drainage system

  19. INNOVATIVE HYBRIDSIL POLY(SILOXANE IMIDE) COMPOSITE REPAIR MATERIALS AND METHODS, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Through the proposed STTR program, NanoSonic and Virginia Tech will create an innovative low viscosity, high Tg copolymer injection repair material and methodology...

  20. Assessing Worker Exposures during Composite Material and Fiberglass Repair: A Special

    Science.gov (United States)

    2015-01-01

    OEEL, without regard to the use of respirators, shall have shower facilities or other suitable decontamination available [32]. 6.4.2 Dust Removal...use mechanically fastened aluminum or stainless steel patches to repair composite material damage, or repair the composite material damage using...world CBRN environment. If the vacuum mechanism of ventilated tools becomes contaminated with radioactive particulates or chemical/biological agents

  1. Web-ADARE: A Web-Aided Data Repairing System

    KAUST Repository

    Gu, Binbin

    2017-03-08

    Data repairing aims at discovering and correcting erroneous data in databases. In this paper, we develop Web-ADARE, an end-to-end web-aided data repairing system, to provide a feasible way to involve the vast data sources on the Web in data repairing. Our main attention in developing Web-ADARE is paid on the interaction problem between web-aided repairing and rule-based repairing, in order to minimize the Web consultation cost while reaching predefined quality requirements. The same interaction problem also exists in crowd-based methods but this is not yet formally defined and addressed. We first prove in theory that the optimal interaction scheme is not feasible to be achieved, and then propose an algorithm to identify a scheme for efficient interaction by investigating the inconsistencies and the dependencies between values in the repairing process. Extensive experiments on three data collections demonstrate the high repairing precision and recall of Web-ADARE, and the efficiency of the generated interaction scheme over several baseline ones.

  2. Web-ADARE: A Web-Aided Data Repairing System

    KAUST Repository

    Gu, Binbin; Li, Zhixu; Yang, Qiang; Xie, Qing; Liu, An; Liu, Guanfeng; Zheng, Kai; Zhang, Xiangliang

    2017-01-01

    Data repairing aims at discovering and correcting erroneous data in databases. In this paper, we develop Web-ADARE, an end-to-end web-aided data repairing system, to provide a feasible way to involve the vast data sources on the Web in data repairing. Our main attention in developing Web-ADARE is paid on the interaction problem between web-aided repairing and rule-based repairing, in order to minimize the Web consultation cost while reaching predefined quality requirements. The same interaction problem also exists in crowd-based methods but this is not yet formally defined and addressed. We first prove in theory that the optimal interaction scheme is not feasible to be achieved, and then propose an algorithm to identify a scheme for efficient interaction by investigating the inconsistencies and the dependencies between values in the repairing process. Extensive experiments on three data collections demonstrate the high repairing precision and recall of Web-ADARE, and the efficiency of the generated interaction scheme over several baseline ones.

  3. Self-repairing of material damage. Sonsho wo jiko shufuku yokushisuru zairyo

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, S [National Research Inst. for Metals, Tsukuba (Japan)

    1994-07-01

    In order to control the damage like crack or void formed during the use of structural material by the material itself, it is required to self-detect the damage, to self-judge the state of damage, and to self-control or self-repair the damage finally. Based on the parameter of length, the repair and control is classified into the 1mm-scale functional fine wire and thin film utilization type, 1[mu]m-scale microcapsule type, and 1nm-scale trace element utilization type. For the damage repair and control of functional fine wire and thin film utilization type, the damage is repaired and controlled by pasting thin film or by embedding fine wire of functional material, such as shape memory alloy, Ti-Ni, and piezoelectric ceramics PZT (lead zirconate titanate), on the material surface or inside the material. For the damage repair and control of microcapsule type, is illustrated the control mechanism of high temperature fatigue crack propagation by Y2O3 particles dispersed in the Fe-20Cr alloy. Furthermore, the formation mechanism of self-repairing film by the trace element is also illustrated. 13 refs., 5 figs.

  4. Rapid Repair of CB Hardened Systems

    National Research Council Canada - National Science Library

    Rappoport, Leonid

    2004-01-01

    .... The adhesive chemistry utilized can quickly, easily and dependably bond the like and unlike substrates together, including Kevlar, polyfluorinated materials, polyolefins, PVC and other materials...

  5. Artificial-Crack-Behavior Test Evaluation of the Water-Leakage Repair Materials Used for the Repair of Water-Leakage Cracks in Concrete Structures

    Directory of Open Access Journals (Sweden)

    Soo-Yeon Kim

    2016-09-01

    Full Text Available There are no existing standard test methods at home and abroad that can verify the performance of water leakage repair materials, and it is thus very difficult to perform quality control checks in the field of water leakage repair. This study determined that the key factors that have the greatest impact on the water leakage repair materials are the micro-behaviors of cracks, and proposed an artificial-crack-behavior test method for the performance verification of the repair materials. The performance of the 15 kinds of repair materials that are currently being used in the field of water leakage repair was evaluated by applying the proposed test method. The main aim of such a test method is to determine if there is water leakage by injecting water leakage repair materials into a crack behavior test specimen with an artificial 5-mm crack width, applying a 2.5 mm vertical behavior load at 100 cycles, and applying 0.3 N/mm2 constant water pressure. The test results showed that of the 15 kinds of repair materials, only two effectively sealed the crack and thus stopped the water leakage. The findings of this study confirmed the effectiveness of the proposed artificial-crack-behavior test method and suggest that it can be used as a performance verification method for checking the responsiveness of the repair materials being used in the field of water leakage repair to the repetitive water leakage behaviors that occur in concrete structures. The study findings further suggest that the use of the proposed test method makes it possible to quantify the water leakage repair quality control in the field.

  6. A bivariate optimal replacement policy for a multistate repairable system

    International Nuclear Information System (INIS)

    Zhang Yuanlin; Yam, Richard C.M.; Zuo, Ming J.

    2007-01-01

    In this paper, a deteriorating simple repairable system with k+1 states, including k failure states and one working state, is studied. It is assumed that the system after repair is not 'as good as new' and the deterioration of the system is stochastic. We consider a bivariate replacement policy, denoted by (T,N), in which the system is replaced when its working age has reached T or the number of failures it has experienced has reached N, whichever occurs first. The objective is to determine the optimal replacement policy (T,N)* such that the long-run expected profit per unit time is maximized. The explicit expression of the long-run expected profit per unit time is derived and the corresponding optimal replacement policy can be determined analytically or numerically. We prove that the optimal policy (T,N)* is better than the optimal policy N* for a multistate simple repairable system. We also show that a general monotone process model for a multistate simple repairable system is equivalent to a geometric process model for a two-state simple repairable system in the sense that they have the same structure for the long-run expected profit (or cost) per unit time and the same optimal policy. Finally, a numerical example is given to illustrate the theoretical results

  7. Biomechanical characteristics of single-row repair in comparison to double-row repair with consideration of the suture configuration and suture material

    OpenAIRE

    Baums, M. H.; Buchhorn, G. H.; Spahn, G.; Poppendieck, B.; Schultz, W.; Klinger, H.-M.

    2008-01-01

    The aim of the study was to evaluate the time zero mechanical properties of single- versus double-row configuration for rotator cuff repair in an animal model with consideration of the stitch technique and suture material. Thirty-two fresh-frozen sheep shoulders were randomly assigned to four repair groups: suture anchor single-row repair coupled with (1) braided, nonabsorbable polyester suture sized USP No. 2 (SRAE) or (2) braided polyblend polyethylene suture sized No. 2 (SRAH). The double-...

  8. Cold standby repairable system with working vacations and vacation interruption

    Institute of Scientific and Technical Information of China (English)

    Baoliang Liu; Lirong Cui; Yanqing Wen

    2015-01-01

    This paper studies a cold standby repairable system with working vacations and vacation interruption. The repairman’s multiple vacations policy, the working vacations policy and the vacation interruption are considered simultaneously. The lifetime of components fol ows a phase-type (PH) distribution. The repair time in the regular repair period and the working vacation period fol ow other two PH distributions at different rates. For this sys-tem, the vector-valued Markov process governing the system is constructed. We obtain several important performance measures for the system in transient and stationary regimes applying matrix-analytic methods. Final y, a numerical example is given to il ustrate the results obtained.

  9. Potential of Carbon Nanotube Reinforced Cement Composites as Concrete Repair Material

    Directory of Open Access Journals (Sweden)

    Tanvir Manzur

    2016-01-01

    Full Text Available Carbon nanotubes (CNTs are a virtually ideal reinforcing agent due to extremely high aspect ratios and ultra high strengths. It is evident from contemporary research that utilization of CNT in producing new cement-based composite materials has a great potential. Consequently, possible practical application of CNT reinforced cementitious composites has immense prospect in the field of applied nanotechnology within construction industry. Several repair, retrofit, and strengthening techniques are currently available to enhance the integrity and durability of concrete structures with cracks and spalling, but applicability and/or reliability is/are often limited. Therefore, there is always a need for innovative high performing concrete repair materials with good mechanical, rheological, and durability properties. Considering the mechanical properties of carbon nanotubes (CNTs and the test results of CNT reinforced cement composites, it is apparent that such composites could be used conveniently as concrete repair material. With this end in view, the applicability of multiwalled carbon nanotube (MWNT reinforced cement composites as concrete repair material has been evaluated in this study in terms of setting time, bleeding, and bonding strength (slant shear tests. It has been found that MWNT reinforced cement mortar has good prospective as concrete repair material since such composites exhibited desirable behavior in setting time, bleeding, and slant shear.

  10. Inducible DNA-repair systems in yeast: competition for lesions.

    Science.gov (United States)

    Mitchel, R E; Morrison, D P

    1987-03-01

    DNA lesions may be recognized and repaired by more than one DNA-repair process. If two repair systems with different error frequencies have overlapping lesion specificity and one or both is inducible, the resulting variable competition for the lesions can change the biological consequences of these lesions. This concept was demonstrated by observing mutation in yeast cells (Saccharomyces cerevisiae) exposed to combinations of mutagens under conditions which influenced the induction of error-free recombinational repair or error-prone repair. Total mutation frequency was reduced in a manner proportional to the dose of 60Co-gamma- or 254 nm UV radiation delivered prior to or subsequent to an MNNG exposure. Suppression was greater per unit radiation dose in cells gamma-irradiated in O2 as compared to N2. A rad3 (excision-repair) mutant gave results similar to wild-type but mutation in a rad52 (rec-) mutant exposed to MNNG was not suppressed by radiation. Protein-synthesis inhibition with heat shock or cycloheximide indicated that it was the mutation due to MNNG and not that due to radiation which had changed. These results indicate that MNNG lesions are recognized by both the recombinational repair system and the inducible error-prone system, but that gamma-radiation induction of error-free recombinational repair resulted in increased competition for the lesions, thereby reducing mutation. Similarly, gamma-radiation exposure resulted in a radiation dose-dependent reduction in mutation due to MNU, EMS, ENU and 8-MOP + UVA, but no reduction in mutation due to MMS. These results suggest that the number of mutational MMS lesions recognizable by the recombinational repair system must be very small relative to those produced by the other agents. MNNG induction of the inducible error-prone systems however, did not alter mutation frequencies due to ENU or MMS exposure but, in contrast to radiation, increased the mutagenic effectiveness of EMS. These experiments demonstrate

  11. Balancing flexibility and inventory in repair inventory systems

    NARCIS (Netherlands)

    Haas, de H.F.M.; Martin, H.H.

    1995-01-01

    In repair inventory systems, failed units are exchanged for serviceable units upon failure. The probability that serviceable units are available to support the exchange process can be used as a measure for the performance of the system. This measure is commonly called the expected fill rate. The

  12. Effective Measurement of Reliability of Repairable USAF Systems

    Science.gov (United States)

    2012-09-01

    ix I. Introduction ...RELIABILITY OF REPAIRABLE USAF SYSTEMS I. Introduction General Issue The United States relies on complex systems to protect and project the national...Under Secretary of Defense for Acquisition, Technology, and Logistics, Implementing a Lifecycle Mangement Framework, Washington DC, DC: DoD, 2008

  13. Closed loop two-echelon repairable item systems

    NARCIS (Netherlands)

    Spanjers, L.; van Ommeren, Jan C.W.; Zijm, Willem H.M.; Liberopoulos, G.; Papadopoulos, C.T.; Tan, B.; MacGregor Smith, J.; Gershwin, S.B.

    2006-01-01

    In this paper we consider closed loop two-echelon epairable item systems with repair facilities both at a number of local service centers (called bases) and at a central location (the depot). The goal of the system is to maintain a number of production facilities (one at each base) in optimal

  14. Mountain Plains Learning Experience Guide: Automotive Repair. Course: Emission Systems.

    Science.gov (United States)

    Schramm, C.; Osland, Walt

    One of twelve individualized courses included in an automotive repair curriculum, this course covers the theory, testing, and servicing of automotive emission control systems. The course is comprised of one unit, Fundamentals of Emission Systems. The unit begins with a Unit Learning Experience Guide that gives directions for unit completion. The…

  15. ARCHER-Advanced System for RPVH Inspection and Repair

    International Nuclear Information System (INIS)

    Tomasic, Tomislav; Vukovic, Igor; Bakic, Ante

    2014-01-01

    array eddy current probes. Surface flaws, discovered by eddy current examination of J-groove weld, define the scope of the automated surface repair module (ASR module) performed by the grinding method. Specially developed grinding procedure, based on the surface probing and UT results, ensures the treatment doesn't affect the originally designed structural integrity basis. When compared with the other repairing methods, ASR module significantly reduces the inspection time and radiation exposure of the personnel, and does not introduce residual stress into the structural material. The paper describes the system's capabilities and features, and its advantages compared to other systems for performing the RPVH inspection and repair activities on PWR and VVER reactors. (authors)

  16. Flexible Software Solution for Information System of Maintenance and Repair in Armenian NPP Medzamor

    International Nuclear Information System (INIS)

    Stoilova Yordanova, V.; Manchev, B.

    2016-01-01

    Achieving high performance in maintenance and repair activities in nuclear facilities and good results in this area is not possible without proper planning. This includes long-term, medium-term and annual planning. A computerized information maintenance management system is a tool widely used by nuclear operators to achieve safe, reliable, stable and predictable plant operation. Development and implementation of such a system in the Armenian NPP Medzamor (ANPP) was initiated by the European Commission (EC) in August 2013 based on the decision of ANPP management to improve practice in terms of planning and carrying out maintenance and repair of plant structures, systems and components (SSCs). The main purpose for the development and deployment of information maintenance management system in ANPP is creation of a systematic approach to the distribution of tasks between the maintenance personnel as well as the timing and methods of their implementation - on which systems, structures and components, maintenance frequency, while the ultimate goal is to optimize the use of resources for maintenance and to ensure plant safe operation and reliability. In November 2013 a contract between European Commission and consortium Risk Engineering -David Holding was signed, including the following supplies: Hardware for the information system of ANPP (called us Archimed MRO); Specification, design and development of the software of Archimed MRO, installation of the system, data migration, training of ANPP staff operating the system, and 9 months trial operation. In the process of specifying the functionality of the system the main purpose was to provide modern information tools to help improve the work of ANPP personnel in the following areas: Optimization of ANPP maintenance program; Planning of maintenance, repair and overhaul (MRO) activities; Effective management of the processes of MRO; Analysis of the MRO results (trend analysis, recurrence of repairs, quality of the repairs

  17. Iterative Repair Planning for Spacecraft Operations Using the Aspen System

    Science.gov (United States)

    Rabideau, G.; Knight, R.; Chien, S.; Fukunaga, A.; Govindjee, A.

    2000-01-01

    This paper describes the Automated Scheduling and Planning Environment (ASPEN). ASPEN encodes complex spacecraft knowledge of operability constraints, flight rules, spacecraft hardware, science experiments and operations procedures to allow for automated generation of low level spacecraft sequences. Using a technique called iterative repair, ASPEN classifies constraint violations (i.e., conflicts) and attempts to repair each by performing a planning or scheduling operation. It must reason about which conflict to resolve first and what repair method to try for the given conflict. ASPEN is currently being utilized in the development of automated planner/scheduler systems for several spacecraft, including the UFO-1 naval communications satellite and the Citizen Explorer (CX1) satellite, as well as for planetary rover operations and antenna ground systems automation. This paper focuses on the algorithm and search strategies employed by ASPEN to resolve spacecraft operations constraints, as well as the data structures for representing these constraints.

  18. MANAGEMENT PROCEDURE OF SUPPLIES OF UNITS, MATERIALS AND CONSTITUENT PARTS FOR REPAIR AND MAINTENANCE SUPPORT OF TRANSPORT AND PRODUCTION MACHINES

    Directory of Open Access Journals (Sweden)

    Victor Yurievich Stroganov

    2017-05-01

    Full Text Available This article considers a question of creation of schemes and sequence of passing of the main stages of process of execution of repair and maintenance works order taking into account formation of stocks of necessary spare parts, materials and constituent parts. Models of an input stream are offered for inventory control system, which are rather adequately described by autoregressive models of order two.

  19. Repair mechanisms inducible to the DNA in I.M.M.S. biological systems

    International Nuclear Information System (INIS)

    Guzman, J.; Arceo, C.; Cortinas, C.; Rosa, M.E. De la; Olvera, O.; Cruces, M.; Pimentel, E.

    1990-03-01

    Given the characteristics of the MMS and the relative antecedents to the repair mechanisms in eucariontes are sought to determine the effect of the MMS on the genetic material and their repair in Drosophila melanogaster. (Author)

  20. Weld repair of helium degraded reactor vessel material

    International Nuclear Information System (INIS)

    Kanne, W.R. Jr.; Lohmeier, D.A.; Louthan, M.R. Jr.; Rankin, D.T.; Franco-Ferreira, E.A.; Bruck, G.J.; Madeyski, A.; Shogan, R.P.; Lessmann, G.G.

    1990-01-01

    Welding methods for modification or repair of irradiated nuclear reactor vessels are being evaluated at the Savannah River Site. A low-penetration weld overlay technique has been developed to minimize the adverse effects of irradiation induced helium on the weldability of metals and alloys. This technique was successfully applied to Type 304 stainless steel test plates that contained 3 to 220 appm helium from tritium decay. Conventional welding practices caused significant cracking and degradation in the test plates. Optical microscopy of weld surfaces and cross sections showed that large surface toe cracks formed around conventional welds in the test plates but did not form around overlay welds. Scattered incipient underbead cracks (grain boundary separations) were associated with both conventional and overlay test welds. Tensile and bend tests were used to assess the effect of base metal helium content on the mechanical integrity of the low-penetration overlay welds. The axis of tensile specimens was perpendicular to the weld-base metal interface. Tensile specimens were machined after studs were resistance welded to overlay surfaces

  1. Repair of uv damaged DNA in systemic lupus erythematosus. [Mice

    Energy Technology Data Exchange (ETDEWEB)

    Beighlie, D J; Teplitz, R L

    1975-06-01

    The NZB NZW hybrid mouse is an animal model of human systemic lupus erythematosus (SLE). Two breeding schemes were devised using NZB, NZW, B/W, and CBA mice, which permit definitive decisions regarding genetic and/or viral origin of the disease. It is proposed that at least two factors must be involved: a genetic abnormality producing hyper-responsiveness to nucleic acid antigens, and a DNA repair defect which results in liberation of DNA and RNA when cells are lethally injured. Evidence is presented for a DNA repair deficit in human SLE lymphocytes following in vitro irradiation with ultraviolet (uv) light. Lymphocytes from adult New Zealand and control mice were found to lack normal amounts of endonuclease necessary for repairing uv damage.

  2. Availability, reliability and downtime of systems with repairable components

    DEFF Research Database (Denmark)

    Kiureghian, Armen Der; Ditlevsen, Ove Dalager; Song, J.

    2007-01-01

    Closed-form expressions are derived for the steady-state availability, mean rate of failure, mean duration of downtime and lower bound reliability of a general system with randomly and independently failing repairable components. Component failures are assumed to be homogeneous Poisson events in ...

  3. Materials management information systems.

    Science.gov (United States)

    1996-01-01

    The hospital materials management function--ensuring that goods and services get from a source to an end user--encompasses many areas of the hospital and can significantly affect hospital costs. Performing this function in a manner that will keep costs down and ensure adequate cash flow requires effective management of a large amount of information from a variety of sources. To effectively coordinate such information, most hospitals have implemented some form of materials management information system (MMIS). These systems can be used to automate or facilitate functions such as purchasing, accounting, inventory management, and patient supply charges. In this study, we evaluated seven MMISs from seven vendors, focusing on the functional capabilities of each system and the quality of the service and support provided by the vendor. This Evaluation is intended to (1) assist hospitals purchasing an MMIS by educating materials managers about the capabilities, benefits, and limitations of MMISs and (2) educate clinical engineers and information system managers about the scope of materials management within a healthcare facility. Because software products cannot be evaluated in the same manner as most devices typically included in Health Devices Evaluations, our standard Evaluation protocol was not applicable for this technology. Instead, we based our ratings on our observations (e.g., during site visits), interviews we conducted with current users of each system, and information provided by the vendor (e.g., in response to a request for information [RFI]). We divided the Evaluation into the following sections: Section 1. Responsibilities and Information Requirements of Materials Management: Provides an overview of typical materials management functions and describes the capabilities, benefits, and limitations of MMISs. Also includes the supplementary article, "Inventory Cost and Reimbursement Issues" and the glossary, "Materials Management Terminology." Section 2. The

  4. DNA Damage Repair System in Plants: A Worldwide Research Update.

    Science.gov (United States)

    Gimenez, Estela; Manzano-Agugliaro, Francisco

    2017-10-30

    Living organisms are usually exposed to various DNA damaging agents so the mechanisms to detect and repair diverse DNA lesions have developed in all organisms with the result of maintaining genome integrity. Defects in DNA repair machinery contribute to cancer, certain diseases, and aging. Therefore, conserving the genomic sequence in organisms is key for the perpetuation of life. The machinery of DNA damage repair (DDR) in prokaryotes and eukaryotes is similar. Plants also share mechanisms for DNA repair with animals, although they differ in other important details. Plants have, surprisingly, been less investigated than other living organisms in this context, despite the fact that numerous lethal mutations in animals are viable in plants. In this manuscript, a worldwide bibliometric analysis of DDR systems and DDR research in plants was made. A comparison between both subjects was accomplished. The bibliometric analyses prove that the first study about DDR systems in plants (1987) was published thirteen years later than that for other living organisms (1975). Despite the increase in the number of papers about DDR mechanisms in plants in recent decades, nowadays the number of articles published each year about DDR systems in plants only represents 10% of the total number of articles about DDR. The DDR research field was done by 74 countries while the number of countries involved in the DDR & Plant field is 44. This indicates the great influence that DDR research in the plant field currently has, worldwide. As expected, the percentage of studies published about DDR systems in plants has increased in the subject area of agricultural and biological sciences and has diminished in medicine with respect to DDR studies in other living organisms. In short, bibliometric results highlight the current interest in DDR research in plants among DDR studies and can open new perspectives in the research field of DNA damage repair.

  5. Robotics in the nuclear environment-inspection and repairs inside the primary coolant system

    International Nuclear Information System (INIS)

    Guillet, J.; Marcel Tortolano

    2005-01-01

    The increase in the lifetime of the power plants and the ageing of materials require the intervention inside the components to carry out controls and possibly repairs in the event of discovered defects. Within this framework, EDF is investigating the feasibility of robotized repairs of the components and pipes of the main primary coolant system of a nuclear power plant. For several years, EDF R and D has engaged projects whose subject of study is the possibility of repairing components such as the main vessel; the pressurizer or the primary coolant pipes with the help of robots and dedicated tools. INTERVENTIONS INSIDE PRIMARY COOLANT PIPES: Studies undertaken by EDF highlighted that certain zones, particularly in pipe connections, can be affected by thermal fatigue which causes crackling defects or crackings. In anticipation of this phenomenon which would affect primary pipes and to avoid their replacements, EDF R and D has been studying the feasibility of examining and repairing these zones using robots. Robotized repair consists in introducing into the pipe while passing by the vessel, a 6 degrees of freedom manipulator mounted on a mobile carrier. This robot implements and carries out the trajectories of the different processes of repair: - Precise localization of the defects, - Elimination (possibly sampling) of the defects by machining, - Control that the defects were eliminated, - Weld metal buildup if the repair cavity is too deep, - Grinding followed by a new control of the surface. These studies and tests were conducted in the laboratory of EDF R and D in Chatou. The sequence of operations included machining by grinding and milling, profilometric control, dye penetrant testing, TIG welding and ultrasonic examinations. The results of the tests, executed on full scale models of components, are satisfactory and show the advantages of robotics compared with classical methods. ROBOTIZED INTERVENTIONS IN THE REACTOR VESSEL: Another difficult issue is the

  6. Integrated material accountancy system

    International Nuclear Information System (INIS)

    Calabozo, M.; Buiza, A.

    1991-01-01

    In this paper we present the system that we are actually using for Nuclear Material Accounting and Manufacturing Management in our UO 2 Fuel Fabrication Plant located at Juzbado, Salamanca, Spain. The system is based mainly on a real time data base which gather data for all the operations performed in our factory from UO 2 powder reception to fuel assemblies shipment to the customers. The accountancy is just an important part of the whole integrated system covering all the aspects related to manufacturing: planning, traceability, Q.C. analysis, production control and accounting data

  7. Evaluation of temporary non-code repairs in safety class 3 piping systems

    International Nuclear Information System (INIS)

    Godha, P.C.; Kupinski, M.; Azevedo, N.F.

    1996-01-01

    Temporary non-ASME Code repairs in safety class 3 pipe and piping components are permissible during plant operation in accordance with Nuclear Regulatory Commission Generic Letter 90-05. However, regulatory acceptance of such repairs requires the licensee to undertake several timely actions. Consistent with the requirements of GL 90-05, this paper presents an overview of the detailed evaluation and relief request process. The technical criteria encompasses both ductile and brittle piping materials. It also lists appropriate evaluation methods that a utility engineer can select to perform a structural integrity assessment for design basis loading conditions to support the use of temporary non-Code repair for degraded piping components. Most use of temporary non-code repairs at a nuclear generating station is in the service water system which is an essential safety related system providing the ultimate heat sink for various plant systems. Depending on the plant siting, the service water system may use fresh water or salt water as the cooling medium. Various degradation mechanisms including general corrosion, erosion/corrosion, pitting, microbiological corrosion, galvanic corrosion, under-deposit corrosion or a combination thereof continually challenge the pressure boundary structural integrity. A good source for description of corrosion degradation in cooling water systems is provided in a cited reference

  8. Recommendations for optimised repair welding operations in steam systems exposed to creep; Rekommendationer foer optimering av svetsreparationer i kryppaakaenda aangsystem

    Energy Technology Data Exchange (ETDEWEB)

    Storesund, Jan; Samuelson, Aake; Klasen, Bjoern; Jensen, Carsten

    2002-03-01

    Recommendations for optimised repair welding in creep exposed steam systems have been produced on basis of different parts of the project which involve a literature survey, case studies, metallographical investigations and finite element simulations. The separate parts are compiled in the present report where the results also are coupled to each other. Two of the project parts are reported in appendices in the present report and the other ones in three separate work reports. The studies have shown evidence of the complexity associated with repair welding and many alternatives may be offered for a given situation. The importance of the factors which may influence the life time of the repair have been investigated and are described in order to facilitate the decision-making process for the given situation. From the obtained results there are also more general recommendations to be given: Make sure that system stresses not are acting at the repair. Avoid welding methods that could result in strongly creep soft HAZs. Select a weld metal for the repair which is slightly creep hard compared to the remaining aged material. Selection of a wide and 'medium' deep excavation geometry as well as a repair around the whole circumference is to be preferred. Repairs of welds that not include excavation of the whole width of the original weld should be avoided. Replica testing is recommended in addition to the common practice in the quality and condition-monitoring control of the repair.

  9. Microtensile Bond Strength of New Ceramic/Polymer Materials Repaired with Composite Resin

    Science.gov (United States)

    2015-06-30

    also have been shown to have higher enamel wear rates than composite-resin CAD/CAM restorations (Mӧrmann et al, 2013). As material choices, cost, and...although the longevity of these repairs has not been validated by clinical studies. Paradigm MZ100 showed the least amount of opposing enamel wear...ability to absorb shock, resist staining and stop crack propagation. Further manufacturer claims are that ceramic/polymer materials are easily

  10. Geopolymers as potential repair material in tiles conservation

    Science.gov (United States)

    Geraldes, Catarina F. M.; Lima, Augusta M.; Delgado-Rodrigues, José; Mimoso, João Manuel; Pereira, Sílvia R. M.

    2016-03-01

    The restoration materials currently used to fill gaps in historical architectural tiles (e.g. lime or organic resin pastes) usually show serious drawbacks in terms of compatibility, effectiveness or durability. The existing solutions do not fully protect Portuguese faïence tiles ( azulejos) in outdoor conditions and frequently result in further deterioration. Geopolymers can be a potential solution for tile lacunae infill, given the chemical-mineralogical similitude to the ceramic body, and also the durability and versatile range of physical properties that can be obtained through the manipulation of their formulation and curing conditions. This work presents and discusses the viability of the use of geopolymeric pastes to fill lacunae in tiles or to act as "cold" cast ceramic tile surrogates reproducing missing tile fragments. The formulation of geopolymers, namely the type of activators, the alumino-silicate source, the quantity of water required for adequate workability and curing conditions, was studied. The need for post-curing desalination was also considered envisaging their application in the restoration of outdoor historical architectural tiles frequently exposed to adverse environmental conditions. The possible advantages and disadvantages of the use of geopolymers in the conservation of tiles are also discussed. The results obtained reveal that geopolymers pastes are a promising material for the restoration of tiles, when compared to other solutions currently in use.

  11. Natural Materials, Systems & Extremophiles

    Science.gov (United States)

    2012-03-06

    system. Linked: FY11 AFRL/RX pgm • Structural Coloration – new area, several PIs moving in and out; MURI (Harvard) • Biopolymers – Mainly silk but...looking at other biopolymers . The silk work is well integrated with AFRL; many exchanges of personnel & material. Some PIs moving out with...it pertains to marking items. • Silk – DARPA has contributed to my existing program. ARO has a single grantee. ONR funds a single investigator. NSF

  12. Optimal Inspection and Repair Strategies for Structural Systems

    DEFF Research Database (Denmark)

    Sommer, A. M.; Nowak, A. S.; Thoft-Christensen, Palle

    1992-01-01

    and a design variable as optimization variables. A model for estimating the total expected costs for structural systems is given including the costs associated with the loss of individual structural members as well as the costs associated with the loss of at least one element of a particular group......A model for reliability-based repair and maintenance strategies of structural systems is described. The total expected costs in the lifetime of the structure are minimized with the number of inspections, the number and positions of the inspected points, the inspection efforts, the repair criteria...... of structural members and the costs associated with the simultaneous loss of all members of a specific group of structural members. The approach is based on the pre-posteriori analysis from the classical decision theory. Special emphasis is given to the problem of selecting the number of points in the structure...

  13. Development of management system for plant repairing work

    International Nuclear Information System (INIS)

    Terauchi, Makoto

    1999-01-01

    In the fast breeder reactor, ''Monju'', in order to conduct nuclear plant repairing works securely and effectively, development of a computer system to assist management business on plant repairing work was begun on 1993. The system has been applied to about 5,000 times of operational management through past four times of plant inspection and to daily inspections and maintenance, and is daily used at working places of ''Monju'' such as issue/management of about 110,000 times of operational prohibition tag in isolated management. And, by automation of issue/management on working sheets and operational prohibition tag and others conducted hitherto by hand, the management business has been largely rationalized. (G.K.)

  14. Space Shuttle Thermal Protection System Repair Flight Experiment Induced Contamination Impacts

    Science.gov (United States)

    Smith, Kendall A.; Soares, Carlos E.; Mikatarian, Ron; Schmidl, Danny; Campbell, Colin; Koontz, Steven; Engle, Michael; McCroskey, Doug; Garrett, Jeff

    2006-01-01

    NASA s activities to prepare for Flight LF1 (STS-114) included development of a method to repair the Thermal Protection System (TPS) of the Orbiter s leading edge should it be damaged during ascent by impacts from foam, ice, etc . Reinforced Carbon-Carbon (RCC) is used for the leading edge TPS. The repair material that was developed is named Non- Oxide Adhesive eXperimental (NOAX). NOAX is an uncured adhesive material that acts as an ablative repair material. NOAX completes curing during the Orbiter s descent. The Thermal Protection System (TPS) Detailed Test Objective 848 (DTO 848) performed on Flight LF1 (STS-114) characterized the working life, porosity void size in a micro-gravity environment, and the on-orbit performance of the repairs to pre-damaged samples. DTO 848 is also scheduled for Flight ULF1.1 (STS-121) for further characterization of NOAX on-orbit performance. Due to the high material outgassing rates of the NOAX material and concerns with contamination impacts to optically sensitive surfaces, ASTM E 1559 outgassing tests were performed to determine NOAX condensable outgassing rates as a function of time and temperature. Sensitive surfaces of concern include the Extravehicular Mobility Unit (EMU) visor, cameras, and other sensors in proximity to the experiment during the initial time after application. This paper discusses NOAX outgassing characteristics, how the amount of deposition on optically sensitive surfaces while the NOAX is being manipulated on the pre-damaged RCC samples was determined by analysis, and how flight rules were developed to protect those optically sensitive surfaces from excessive contamination where necessary.

  15. The necessity of a theory of biology for tissue engineering: metabolism-repair systems.

    Science.gov (United States)

    Ganguli, Suman; Hunt, C Anthony

    2004-01-01

    Since there is no widely accepted global theory of biology, tissue engineering and bioengineering lack a theoretical understanding of the systems being engineered. By default, tissue engineering operates with a "reductionist" theoretical approach, inherited from traditional engineering of non-living materials. Long term, that approach is inadequate, since it ignores essential aspects of biology. Metabolism-repair systems are a theoretical framework which explicitly represents two "functional" aspects of living organisms: self-repair and self-replication. Since repair and replication are central to tissue engineering, we advance metabolism-repair systems as a potential theoretical framework for tissue engineering. We present an overview of the framework, and indicate directions to pursue for extending it to the context of tissue engineering. We focus on biological networks, both metabolic and cellular, as one such direction. The construction of these networks, in turn, depends on biological protocols. Together these concepts may help point the way to a global theory of biology appropriate for tissue engineering.

  16. Investigation on Failures of Composite Beam and Substrate Concrete due to Drying Shrinkage Property of Repair Materials

    Science.gov (United States)

    Pattnaik, Rashmi Ranjan

    2017-06-01

    A Finite Element Analysis (FEA) and an experimental study was conducted on composite beam of repair material and substrate concrete to investigate the failures of the composite beam due to drying shrinkage property of the repair materials. In FEA, the stress distribution in the composite beam due to two concentrate load and shrinkage of repair materials were investigated in addition to the deflected shape of the composite beam. The stress distributions and load deflection shapes of the finite element model were investigated to aid in analysis of the experimental findings. In the experimental findings, the mechanical properties such as compressive strength, split tensile strength, flexural strength, and load-deflection curves were studied in addition to slant shear bond strength, drying shrinkage and failure patterns of the composite beam specimens. Flexure test was conducted to simulate tensile stress at the interface between the repair material and substrate concrete. The results of FEA were used to analyze the experimental results. It was observed that the repair materials with low drying shrinkage are showing compatible failure in the flexure test of the composite beam and deform adequately in the load deflection curves. Also, the flexural strength of the composite beam with low drying shrinkage repair materials showed higher flexural strength as compared to the composite beams with higher drying shrinkage value of the repair materials even though the strength of those materials were more.

  17. On some steady-state characteristics of systems with gradual repair

    International Nuclear Information System (INIS)

    Finkelstein, Maxim; Ludick, Zani

    2014-01-01

    We consider a repairable system with continuous output that alternates between states of operation and repair. The output of the system in the operating state is represented by a continuous, decreasing function of time. We assume that during the repair state, the system can produce output that is modelled by an increasing stochastic process. The repair action gradually restores the output of the system to its initial level and it returns to the operating state. We obtain and analyse expressions for the generalized availability and related characteristics of systems with gradual repair and consider several meaningful examples

  18. The development of a remote repair system for deep water pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Frazer, Ian; Giles, John [Stolt Offshore MS Ltd., Aberdeen (United Kingdom)

    2000-07-01

    The ability to maintain a high level of flexibility within the contingency plans for sub sea pipeline repair is a critical issue normally achieved by basing the repair plans on diver intervention. This allows the pipeline operator flexibility to respond to particular repair situations as they occur, minimize up front planning and optimize the investment in repair equipment and stock. However for deep water pipelines all intervention must be performed by remote methods, which require the development of suitable equipment and more detailed repair procedures. This paper describes the development of a remotely operated pipeline repair system capable of working down to 3000 m and allowing a relatively high level of flexibility with minimum investment in repair stock. The repair system is based upon the Modular Advanced Tie-In System (MATIS) which has been successfully developed for the tie-in of deep water flow lines. The MATIS repair system is based on the use of standard flanges to replace a damaged section of pipe with a spool piece in a similar manner to a hyperbaric welded repair. Various repair scenarios are discussed in the paper together with the equipment and the procedures used to perform the repair. The paper will also discuss the other remote repair options such as hot tapping and friction stitch welding. (author)

  19. Modelling open pit shovel-truck systems using the Machine Repair Model

    Energy Technology Data Exchange (ETDEWEB)

    Krause, A.; Musingwini, C. [CBH Resources Ltd., Sydney, NSW (Australia). Endeaver Mine

    2007-08-15

    Shovel-truck systems for loading and hauling material in open pit mines are now routinely analysed using simulation models or off-the-shelf simulation software packages, which can be very expensive for once-off or occasional use. The simulation models invariably produce different estimations of fleet sizes due to their differing estimations of cycle time. No single model or package can accurately estimate the required fleet size because the fleet operating parameters are characteristically random and dynamic. In order to improve confidence in sizing the fleet for a mining project, at least two estimation models should be used. This paper demonstrates that the Machine Repair Model can be modified and used as a model for estimating truck fleet size in an open pit shovel-truck system. The modified Machine Repair Model is first applied to a virtual open pit mine case study. The results compare favourably to output from other estimation models using the same input parameters for the virtual mine. The modified Machine Repair Model is further applied to an existing open pit coal operation, the Kwagga Section of Optimum Colliery as a case study. Again the results confirm those obtained from the virtual mine case study. It is concluded that the Machine Repair Model can be an affordable model compared to off-the-shelf generic software because it is easily modelled in Microsoft Excel, a software platform that most mines already use.

  20. Repair process and a repaired component

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, III, Herbert Chidsey; Simpson, Stanley F.

    2018-02-20

    Matrix composite component repair processes are disclosed. The matrix composite repair process includes applying a repair material to a matrix composite component, securing the repair material to the matrix composite component with an external securing mechanism and curing the repair material to bond the repair material to the matrix composite component during the securing by the external securing mechanism. The matrix composite component is selected from the group consisting of a ceramic matrix composite, a polymer matrix composite, and a metal matrix composite. In another embodiment, the repair process includes applying a partially-cured repair material to a matrix composite component, and curing the repair material to bond the repair material to the matrix composite component, an external securing mechanism securing the repair material throughout a curing period, In another embodiment, the external securing mechanism is consumed or decomposed during the repair process.

  1. Rutting Performance of Cold-Applied Asphalt Repair Materials for Airfield Pavements

    Science.gov (United States)

    2017-06-23

    this study. Cold mix asphalt materials, further denoted cold mixes , were selected to reasonably represent available products on the market and were...pavement repair, primarily because of the small quantities involved and/or the unavailability of hot- mixed asphalt. These cold-applied mixtures have...poorer rutting resistance than hot mix asphalt because additives, often solvent, are required to provide adequate workability for them to be placed

  2. Biomechanical characteristics of single-row repair in comparison to double-row repair with consideration of the suture configuration and suture material.

    Science.gov (United States)

    Baums, M H; Buchhorn, G H; Spahn, G; Poppendieck, B; Schultz, W; Klinger, H-M

    2008-11-01

    The aim of the study was to evaluate the time zero mechanical properties of single- versus double-row configuration for rotator cuff repair in an animal model with consideration of the stitch technique and suture material. Thirty-two fresh-frozen sheep shoulders were randomly assigned to four repair groups: suture anchor single-row repair coupled with (1) braided, nonabsorbable polyester suture sized USP No. 2 (SRAE) or (2) braided polyblend polyethylene suture sized No. 2 (SRAH). The double-row repair was coupled with (3) USP No. 2 (DRAE) or (4) braided polyblend polyethylene suture No. 2 (DRAH). Arthroscopic Mason-Allen stitches were used (single-row) and combined with medial horizontal mattress stitches (double-row). Shoulders were cyclically loaded from 10 to 180 N. Displacement to gap formation of 5- and 10-mm at the repair site, cycles to failure, and the mode of failure were determined. The ultimate tensile strength was verified in specimens that resisted to 3,000 cycles. DRAE and DRAH had a lower frequency of 5- (P = 0.135) and 10-mm gap formation (P = 0.135). All DRAE and DRAH resisted 3,000 cycles while only three SRAE and one SRAH resisted 3,000 cycles (P row specimens was significantly higher than in others (P 0.05). Double-row suture anchor repair with arthroscopic Mason-Allen/medial mattress stitches provides initial strength superior to single-row repair with arthroscopic Mason-Allen stitches under isometric cyclic loading as well as under ultimate loading conditions. Our results support the concept of double-row fixation with arthroscopic Mason-Allen/medial mattress stitches in rotator cuff tears with improvement of initial fixation strength and ultimate tensile load. Use of new polyblend polyethylene suture material seems not to increase the initial biomechanical aspects of the repair construct.

  3. DNA repair

    International Nuclear Information System (INIS)

    Setlow, R.

    1978-01-01

    Some topics discussed are as follows: difficulty in extrapolating data from E. coli to mammalian systems; mutations caused by UV-induced changes in DNA; mutants deficient in excision repair; other postreplication mechanisms; kinds of excision repair systems; detection of repair by biochemical or biophysical means; human mutants deficient in repair; mutagenic effects of UV on XP cells; and detection of UV-repair defects among XP individuals

  4. Chemistry and Bioactivity of NeoMTA Plus™ versus MTA Angelus® Root Repair Materials

    Directory of Open Access Journals (Sweden)

    Sawsan T. Abu Zeid

    2017-01-01

    Full Text Available Objectives. To analyse the chemistry and bioactivity of NeoMTA Plus in comparison with the conventional root repair materials. Method and Materials. Unhydrated and hydrated (initial and final sets materials were analysed by Fourier transform infrared (FTIR spectroscopy and X-ray diffraction (XRD. For bioactivity study, small holes of dentin discs were filled with either materials, immersed in PBS for 15 days, and analysed with FTIR and scanning electron microscope with energy dispersive X-ray (SEM/EDX. The calculation of crystallinity and carbonate/phosphate (CO3/PO4 ratio of surface precipitates (from FTIR and calcium/phosphate (Ca/P ratio (from EDX was statistically analysed using t-test or ANOVA, respectively, at 0.05 significance. Results. Both materials are tricalcium silicate-based that finally react to be calcium silicate hydrate. NeoMTA Plus has relatively high aluminium and sulfur content, with tantalum oxide as an opacifier instead of zirconium oxide in MTA Angelus. NeoMTA Plus showed better apatite formation, higher crystallinity and Ca/P but lower CO3/PO4 ratio than MTA Angelus. SEM showed globular structure with a small particle size in NeoMTA Plus while spherical structure with large particle size in MTA Angelus. Conclusion. Due to fast setting, higher crystallinity, and better bioactivity of NeoMTA Plus, it can be used as a pulp and root repair material.

  5. Planning of Maintenance and Repair of Complicated Technical Systems

    Directory of Open Access Journals (Sweden)

    N. I. Liseychikov

    2004-01-01

    Full Text Available It is expedient to use mathematical models for substantiation of operational material consumption at maintenance of complicated technical systems. The appropriate tasks have been considered: minimization of operational material consumption; determination of maximum scope of work to be executed while maintaining one system; optimization of operational material consumption while organizing maintenance of a system group; planning of technical maintenance and determination of a number of systems to be maintained. Formalization and solution of the above problems have been accomplished.

  6. Molecular mechanism of short-patch repair of radiation-damaged DNA by in vitro reconstituted systems

    International Nuclear Information System (INIS)

    Matsumoto, Y.; Kim, K.; Biade, S.

    1995-01-01

    Objective: Short-patch excision repair is the major pathway to correct DNA damage such as modified bases, apurinic/apyrimidinic (AP) sites and single-strand breaks. Recently this repair reaction was demonstrated to proceed by two alternative pathways: DNA polymerase β (pol β)-dependent pathway and proliferating cell nuclear antigen (PCNA)-dependent pathway. In this work, we focused to compare substrate specificity of these two repair pathways and elucidate their roles in cellular responses to radiation damage. Materials and Methods: Three protein fractions, AP endonuclease, pol β, and BE-1B, which are required for the pol β-dependent pathway, and five protein fractions, AP endonuclease, BE-1B (these two are common to the pol β-dependent pathway), PCNA, pol δ, and BE-2, which are essential for the PCNA-dependent pathway were obtained from Xenopus laevis ovaries through column chromatography. The circular DNA containing either one of the following three lesions: a natural AP site, its synthetic analog, 3-hydroxy-2-hydroxymethyltetrahydrofuran (tetrahydrofuran), and 5-iododeoxyuridine (IdU), was prepared by in vitro ligation of oligonucleotides to a gapped circular DNA. The IdU-containing DNA was irradiated with 312 nm UV light prior to repair reaction. In addition, DNA carrying a single-strand break was obtained by Cs-137 irradiation. Repair reactions of these substrate DNAs were conducted with either the reconstituted system for the pol β-dependent pathway or the one for the PCNA-dependent pathway. After the reaction, repaired and unrepaired DNAs were separated by gel electrophoresis and quantitated. Results: The pol β-dependent reconstituted system was able to repair natural AP sites but not tetrahydrofuran sites or UV-irradiated IdU. The single-strand breaks generated by γ-irradiation were partially repaired by thepol β-dependent pathway. The PCNA-dependent system was able to repair natural AP sites, tetrahydrofuran sites, and most of the single

  7. Availability estimation of repairable systems using reliability graph with general gates (RGGG)

    International Nuclear Information System (INIS)

    Goh, Gyoung Tae

    2009-02-01

    By performing risk analysis, we may obtain sufficient information about the system to redesign it and lower the probability of the occurrence of an accident or mitigate the ensuing consequences. The concept of reliability is widely used to express risk of systems. The reliability is used for non-repairable systems. But nuclear power plant systems are repairable systems. With repairable systems, repairable components can improve the availability of a system because faults that are generated in components can be recovered. Hence, the availability of the system is more proper concept in case of repairable systems. Reliability graph with general gate (RGGG) is one of the system reliability analysis methods. The RGGG is a very intuitiveness method as compared with other methods. But the RGGG has not been applied to repairable systems yet. The objective of this study is to extend the RGGG in order to enable one to analyze repairable system. Determining the probability table for each node is a critical process to calculate the system availability in the RGGG method. Therefore finding the proper algorithms and making probability tables in various situations are the major a part of this study. The other part is an example of applying RGGG method to a real system. We find the proper algorithms and probability tables for independent repairable systems, dependent series repairable systems, and k-out-of-m (K/M) redundant parallel repairable systems in this study. We can evaluate the availability of real system using these probability tables. An example for a real system is shown in the latter part of this study. For the purpose of this analysis, the charging pumps subsystem of the chemical and volume control system (CVCS) was selected. The RGGG method extended for repairable systems has the same characteristic of intuitiveness as the original RGGG method and we can confirm that the availability analysis result from the repairable RGGG method is exact

  8. Nerve autografts and tissue-engineered materials for the repair of peripheral nerve injuries: a 5-year bibliometric analysis

    Directory of Open Access Journals (Sweden)

    Yuan Gao

    2015-01-01

    Full Text Available With advances in biomedical methods, tissue-engineered materials have developed rapidly as an alternative to nerve autografts for the repair of peripheral nerve injuries. However, the materials selected for use in the repair of peripheral nerve injuries, in particular multiple injuries and large-gap defects, must be chosen carefully. Various methods and materials for protecting the healthy tissue and repairing peripheral nerve injuries have been described, and each method or material has advantages and disadvantages. Recently, a large amount of research has been focused on tissue-engineered materials for the repair of peripheral nerve injuries. Using the keywords "pe-ripheral nerve injury", "autotransplant", "nerve graft", and "biomaterial", we retrieved publications using tissue-engineered materials for the repair of peripheral nerve injuries appearing in the Web of Science from 2010 to 2014. The country with the most total publications was the USA. The institutions that were the most productive in this field include Hannover Medical School (Germany, Washington University (USA, and Nantong University (China. The total number of publications using tissue-engineered materials for the repair of peripheral nerve injuries grad-ually increased over time, as did the number of Chinese publications, suggesting that China has made many scientific contributions to this field of research.

  9. Reliability analysis for a circular consecutive-2-out-of-n:F repairable system with priority in repair

    International Nuclear Information System (INIS)

    Zhang Yuanlin; Zuo, Ming J.; Yam, Richard C.M.

    2000-01-01

    A circular consecutive-2-out-of-n:F repairable system with one repairman is studied in this paper. When there are more than one failed component, priorities are assigned to the failed components. Both the working time and the repair time of each component is assumed to be exponentially distributed. Every component after repair is as good as new. By using the definition of generalized transition probability and the concept of critical component, we derive the state transition probability matrix of the system. Methodologies are then presented for the derivation of system reliability indexes such as availability, rate of occurrence of failure, mean time between failures, reliability, and mean time to first failure

  10. Polyethylene glycol as a promising synthetic material for repair of spinal cord injury

    Directory of Open Access Journals (Sweden)

    Xian-bin Kong

    2017-01-01

    Full Text Available Polyethylene glycol is a synthetic, biodegradable, and water-soluble polyether. Owing to its good biological and material properties, polyethylene glycol shows promise in spinal cord tissue engineering applications. Although studies have examined repairing spinal cord injury with polyethylene glycol, these compelling findings have not been recently reviewed or evaluated as a whole. Thus, we herein review and summarize the findings of studies conducted both within and beyond China that have examined the repair of spinal cord injury using polyethylene glycol. The following summarizes the results of studies using polyethylene glycol alone as well as coupled with polymers or hydrogels: (1 polyethylene glycol as an adjustable biomolecule carrier resists nerve fiber degeneration, reduces the inflammatory response, inhibits vacuole and scar formation, and protects nerve membranes in the acute stage of spinal cord injury. (2 Polyethylene glycol-coupled polymers not only promote angiogenesis but also carry drugs or bioactive molecules to the injury site. Because such polymers cross both the blood-spinal cord and blood-brain barriers, they have been widely used as drug carriers. (3 Polyethylene glycol hydrogels have been used as supporting substrates for the growth of stem cells after injury, inducing cell migration, proliferation, and differentiation. Simultaneously, polyethylene glycol hydrogels isolate or reduce local glial scar invasion, promote and guide axonal regeneration, cross the transplanted area, and re-establish synaptic connections with target tissue, thereby promoting spinal cord repair. On the basis of the reviewed studies, we conclude that polyethylene glycol is a promising synthetic material for use in the repair of spinal cord injury

  11. Polyethylene glycol as a promising synthetic material for repair of spinal cord injury

    Institute of Scientific and Technical Information of China (English)

    Xian-bin Kong; Qiu-yan Tang; Xu-yi Chen; Yue Tu; Shi-zhong Sun; Zhong-lei Sun

    2017-01-01

    Polyethylene glycol is a synthetic, biodegradable, and water-soluble polyether. Owing to its good biological and material properties, polyethylene glycol shows promise in spinal cord tissue engineering applications. Although studies have examined repairing spinal cord injury with polyethylene glycol, these compellingfindings have not been recently reviewed or evaluated as a whole. Thus, we herein review and summarize the findings of studies conducted both within and beyond China that have examined the repair of spinal cord injury using polyethylene glycol. The following summarizes the results of studies using polyethylene glycol alone as well as coupled with polymers or hydrogels: (1) polyethylene glycol as an adjustable bio-molecule carrier resists nerve fiber degeneration, reduces the inflammatory response, inhibits vacuole and scar formation, and protects nerve membranes in the acute stage of spinal cord injury. (2) Polyethylene glycol-coupled polymers not only promote angiogenesis but also carry drugs or bioactive molecules to the injury site. Because such polymers cross both the blood-spinal cord and blood-brain barriers, they have been widely used as drug carriers. (3) Polyethylene glycol hydrogels have been used as supporting sub-strates for the growth of stem cells after injury, inducing cell migration, proliferation, and differentiation. Simultaneously, polyethylene glycol hydrogels isolate or reduce local glial scar invasion, promote and guide axonal regeneration, cross the transplanted area, and re-establish synaptic connections with target tissue, thereby promoting spinal cord repair. On the basis of the reviewed studies, we conclude that polyethylene glycol is a promising synthetic material for use in the repair of spinal cord injury.

  12. Development and Evaluation of Cement-Based Materials for Repair of Corrosion-Damaged Reinforced Concrete Slabs

    OpenAIRE

    Liu, Rongtang; Olek, J.

    2001-01-01

    In this study, the results of an extensive laboratory investigation conducted to evaluate the properties of concrete mixes used as patching materials to repair reinforced concrete slabs damaged by corrosion are reported. Seven special concrete mixes containing various combinations of chemical or mineral admixtures were developed and used as a patching material to improve the durability of the repaired slabs. Physical and mechanical properties of these mixes, such as compressive strength, stat...

  13. [Preparation of sodium alginate-nanohydroxyapatite composite material for bone repair and its biocompatibility].

    Science.gov (United States)

    Wang, Yanmei; He, Jiacai; Li, Quanli; Shen, Jijia

    2014-02-01

    To prepare sodium alginate-nanohydroxyapatite composite material and to explore its feasibility as a bone repair material. Sodium alginate-nanohydroxyapatite composite material was prepared using chemical cross-linking and freeze-drying technology. The composite was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) and its porosity was measured by liquid displacement method. The fifth passage of bone marrow stromal stem cells (BMSCs) were incubated on the composite material and then growth was observed by inverted microscope and SEM. BMSCs were cultured with liquid extracts of the material, methyl thiazolyl tetrazolium (MTT) assay was used to calculate the relative growth rate (RGR) on 1, 3, 5 d and to evaluate the cytotoxicity. Fresh dog blood was added into the liquid extracts to conduct hemolysis test, the spectrophotometer was used to determine the optical density (OD) and to calculate the hemolysis rate. Sodium alginate-nanohydroxyapatite composite material displayed porosity, the porous pore rate was (88.6 +/- 4.5)%. BMSCs showed full stretching and vigorous growth under inverted microscope and SEM. BMSCs cultured with liquid extracts of the material had good activities. The toxicity of composite material was graded as 1. Hemolysis test results showed that the hemolysis rate of the composite material was 1.28%, thus meeting the requirement of medical biomaterials. The composite material fabricated in this study has high porosity and good biocompatibility.

  14. Direct Self-Repairing Control for Quadrotor Helicopter Attitude Systems

    Directory of Open Access Journals (Sweden)

    Huiliao Yang

    2014-01-01

    Full Text Available A quadrotor helicopter with uncertain actuator faults, such as loss of effectiveness and lock-in-place, is studied in this paper. An adaptive fuzzy sliding mode controller based on direct self-repairing control is designed for such nonlinear system to track the desired output signal, when any actuator of this quadrotor helicopter is loss of effectiveness or stuck at some place. Moreover, using the Lyapunov stability theory, the stability of the whole system and the convergence of the tracking error can be guaranteed. Finally, the availability of the proposed method is verified by simulation on 3-DOF hover to ensure that the system performance under faulty conditions can be quickly recovered to its normal level. And this proposed method is also proved to be better than that of LQR through simulation.

  15. Evaluation of Uniform Cost Accounting System to Fully Capture Depot Level Repair Costs.

    Science.gov (United States)

    1985-12-01

    RD-RI65 522 EVALUATION OF UNIFORM COST ACCOUNTING SYSTEM TO FULLY i/I CAPTURE DEPOT LEVEL REPAIR COSTS (U) NAVAL POSTGRADUATE SCHOOL MONTEREY CA D R...8217.LECTE B ,- THESIS EVALUATION OF UNIFORM COST ACCOUNTING SYSTEM 0TO FULLY CAPTURE DEPOT LEVEL REPAIR COSTS Jby __jDavid Richmond O’Brien lj,,, December...Include Security Classification) EVALUATION OF UNIFORM COST ACCOUNTING SYSTEM TO FULLY CAPTURE DEPOT LEVEL REPAIR COSTS 12 PERSONAL AUTHOR(S) O’Brien- David

  16. Efficacy of ceramic repair material on the bond strength of composite resin to zirconia ceramic.

    Science.gov (United States)

    Kirmali, Omer; Kapdan, Alper; Harorli, Osman Tolga; Barutcugil, Cagatay; Ozarslan, Mehmet Mustafa

    2015-01-01

    The aim of this study was to evaluate the shear bond strength of composite resin in five different repair systems. Sixty specimens (7 mm in diameter and 3 mm in height) of zirconia ceramic were fabricated. All specimen surfaces were prepared with a 30 µm fine diamond rotary cutting instrument with water irrigation for 10 s and dried with oil-free air. Specimens were then randomly divided into six groups for the following different intra-oral repair systems (n = 10): Group 1, control group; Group 2, Cojet system (3M ESPE, Seefeld, Germany); Group 3, Cimara® System (Voco, Cuxhaven, Germany); Group 4, Z-Prime Plus System (Bisco Inc., Schaumburg, IL); Group 5, Clearfil™ System (Kuraray, Osaka, Japan); and Group 6, Z-Bond System (Danville, CA). After surface conditioning, a composite resin Grandio (Voco, Cuxhaven, Germany) was applied to the zirconia surface using a cylindrical mold (5 mm in diameter and 3 mm in length) and incrementally filled up, according to the manufacturer's instructions of each intra-oral system. Each specimen was subjected to a shear load at a crosshead speed of 1 mm/min until fracture. One-way analysis of variance (ANOVA) and Tukey post-hoc tests were used to analyze the bond strength values. There were significant differences between Groups 2-6 and Group 1. The highest bond strength values were obtained with Group 2 (17.26 ± 3.22) and Group 3 (17.31 ± 3.62), while the lowest values were observed with Group 1 (8.96 ± 1.62) and Group 6 (12.85 ± 3.95). All repair systems tested increased the bond strength values between zirconia and composite resin that used surface grinding with a diamond bur.

  17. Guardians of the mycobacterial genome: A review on DNA repair systems in Mycobacterium tuberculosis.

    Science.gov (United States)

    Singh, Amandeep

    2017-12-01

    The genomic integrity of Mycobacterium tuberculosis is continuously threatened by the harsh survival conditions inside host macrophages, due to immune and antibiotic stresses. Faithful genome maintenance and repair must be accomplished under stress for the bacillus to survive in the host, necessitating a robust DNA repair system. The importance of DNA repair systems in pathogenesis is well established. Previous examination of the M. tuberculosis genome revealed homologues of almost all the major DNA repair systems, i.e. nucleotide excision repair (NER), base excision repair (BER), homologous recombination (HR) and non-homologous end joining (NHEJ). However, recent developments in the field have pointed to the presence of novel proteins and pathways in mycobacteria. Homologues of archeal mismatch repair proteins were recently reported in mycobacteria, a pathway previously thought to be absent. RecBCD, the major nuclease-helicase enzymes involved in HR in E. coli, were implicated in the single-strand annealing (SSA) pathway. Novel roles of archeo-eukaryotic primase (AEP) polymerases, previously thought to be exclusive to NHEJ, have been reported in BER. Many new proteins with a probable role in DNA repair have also been discovered. It is now realized that the DNA repair systems in M. tuberculosis are highly evolved and have redundant backup mechanisms to mend the damage. This review is an attempt to summarize our current understanding of the DNA repair systems in M. tuberculosis.

  18. Nano-modified cement composites and its applicability as concrete repair material

    Science.gov (United States)

    Manzur, Tanvir

    Nanotechnology or Nano-science, considered the forth industrial revolution, has received considerable attention in the past decade. The physical properties of a nano-scaled material are entirely different than that of bulk materials. With the emerging nanotechnology, one can build material block atom by atom. Therefore, through nanotechnology it is possible to enhance and control the physical properties of materials to a great extent. Composites such as concrete materials have very high strength and Young's modulus but relatively low toughness and ductility due to their covalent bonding between atoms and lacking of slip systems in the crystal structures. However, the strength and life of concrete structures are determined by the microstructure and mass transfer at nano scale. Cementitious composites are amenable to manipulation through nanotechnology due to the physical behavior and size of hydration products. Carbon nanotubes (CNT) are nearly ideal reinforcing agent due to extremely high aspect ratios and ultra high strengths. So there is a great potential to utilize CNT in producing new cement based composite materials. It is evident from the review of past literature that mechanical properties of nanotubes reinforced cementitious composites have been highly variable. Some researches yielded improvement in performance of CNT-cement composites as compared to plain cement samples, while other resulted in inconsequential changes in mechanical properties. Even in some cases considerable less strengths and modulus were obtained. Another major difficulty of producing CNT reinforced cementitious composites is the attainment of homogeneous dispersion of nanotubes into cement but no standard procedures to mix CNT within the cement is available. CNT attract more water to adhere to their surface due to their high aspect ratio which eventually results in less workability of the cement mix. Therefore, it is extremely important to develop a suitable mixing technique and an

  19. Injectable systems and implantable conduits for peripheral nerve repair

    International Nuclear Information System (INIS)

    Lin, Yen-Chih; Marra, Kacey G

    2012-01-01

    Acute sensory problems following peripheral nerve injury include pain and loss of sensation. Approximately 360 000 people in the United States suffer from upper extremity paralytic syndromes every year. Restoration of sufficient functional recovery after long-gap peripheral nerve damage remains a clinical challenge. Potential nerve repair therapies have increased in the past decade as the field of tissue engineering expands. The following review describes the use of biomaterials in nerve tissue engineering. Namely, the use of both synthetic and natural biomaterials, including non-degradable and degradable nerve grafts, is addressed. The enhancement of axonal regeneration can be achieved by further modification of the nerve guides. These approaches include injectable hydrogel fillers, controlled drug delivery systems, and cell incorporation. Hydrogels are a class of liquid–gel biomaterials with high water content. Injectable and gelling hydrogels can serve as growth factor delivery vehicles and cell carriers for tissue engineering applications. While natural hydrogels and polymers are suitable for short gap nerve repair, the use of polymers for relatively long gaps remains a clinical challenge. (paper)

  20. Extending minimal repair models for repairable systems: A comparison of dynamic and heterogeneous extensions of a nonhomogeneous Poisson process

    International Nuclear Information System (INIS)

    Asfaw, Zeytu Gashaw; Lindqvist, Bo Henry

    2015-01-01

    For many applications of repairable systems, the minimal repair assumption, which leads to nonhomogeneous Poisson processes (NHPP), is not adequate. We review and study two extensions of the NHPP, the dynamic NHPP and the heterogeneous NHPP. Both extensions are motivated by specific aspects of potential applications. It has long been known, however, that the two paradigms are essentially indistinguishable in an analysis of failure data. We investigate the connection between the two approaches for extending NHPP models, both theoretically and numerically in a data example and a simulation study. - Highlights: • Review of dynamic extension of a minimal repair model (LEYP), introduced by Le Gat. • Derivation of likelihood function and comparison to NHPP model with heterogeneity. • Likelihood functions and conditional intensities are similar for the models. • ML estimation is considered for both models using a power law baseline. • A simulation study illustrates and confirms findings of the theoretical study

  1. A deteriorating two-system with two repair modes and sojourn times phase-type distributed

    International Nuclear Information System (INIS)

    Montoro-Cazorla, Delia; Perez-Ocon, Rafael

    2006-01-01

    We study a two-unit cold standby system in steady-state. The online unit goes through a finite number of stages of successive degradation preceding the failure. The units are reparable, there is a repairman and two types of maintenance are considered, preventive and corrective. The preventive repair aims to improve the degradation of a unit being operative. The corrective repair is necessary when the unit fails. We will assume that the preventive repair will be interrupted in favour of a corrective repair in order to increase the availability of the system. The random operational and repair times follow phase-type distributions. For this system, the stationary probability vector, the replacement times, and the involved costs are calculated. An optimisation problem is illustrated by a numerical example. In this, the optimal degradation stage for the preventive repair of the online unit is determined by taking into account the system availability and the incurred costs

  2. A deteriorating two-system with two repair modes and sojourn times phase-type distributed

    Energy Technology Data Exchange (ETDEWEB)

    Montoro-Cazorla, Delia [Departamento de Estadistica e I.O., Escuela Politecnica de Linares, Universidad de Jaen, 23700 Linares, Jaen (Spain); Perez-Ocon, Rafael [Departamento de Estadistica e I.O., Facultad de Ciencias, Universidad de Granada, Granada 18071 (Spain)]. E-mail: rperezo@ugr.es

    2006-01-01

    We study a two-unit cold standby system in steady-state. The online unit goes through a finite number of stages of successive degradation preceding the failure. The units are reparable, there is a repairman and two types of maintenance are considered, preventive and corrective. The preventive repair aims to improve the degradation of a unit being operative. The corrective repair is necessary when the unit fails. We will assume that the preventive repair will be interrupted in favour of a corrective repair in order to increase the availability of the system. The random operational and repair times follow phase-type distributions. For this system, the stationary probability vector, the replacement times, and the involved costs are calculated. An optimisation problem is illustrated by a numerical example. In this, the optimal degradation stage for the preventive repair of the online unit is determined by taking into account the system availability and the incurred costs.

  3. Turbine repair process, repaired coating, and repaired turbine component

    Science.gov (United States)

    Das, Rupak; Delvaux, John McConnell; Garcia-Crespo, Andres Jose

    2015-11-03

    A turbine repair process, a repaired coating, and a repaired turbine component are disclosed. The turbine repair process includes providing a turbine component having a higher-pressure region and a lower-pressure region, introducing particles into the higher-pressure region, and at least partially repairing an opening between the higher-pressure region and the lower-pressure region with at least one of the particles to form a repaired turbine component. The repaired coating includes a silicon material, a ceramic matrix composite material, and a repaired region having the silicon material deposited on and surrounded by the ceramic matrix composite material. The repaired turbine component a ceramic matrix composite layer and a repaired region having silicon material deposited on and surrounded by the ceramic matrix composite material.

  4. DNA repair systems and the pathogenesis of Mycobacterium tuberculosis: varying activities at different stages of infection.

    Science.gov (United States)

    Gorna, Alina E; Bowater, Richard P; Dziadek, Jaroslaw

    2010-05-25

    Mycobacteria, including most of all MTB (Mycobacterium tuberculosis), cause pathogenic infections in humans and, during the infectious process, are exposed to a range of environmental insults, including the host's immune response. From the moment MTB is exhaled by infected individuals, through an active and latent phase in the body of the new host, until the time they reach the reactivation stage, MTB is exposed to many types of DNA-damaging agents. Like all cellular organisms, MTB has efficient DNA repair systems, and these are believed to play essential roles in mycobacterial pathogenesis. As different stages of infection have great variation in the conditions in which mycobacteria reside, it is possible that different repair systems are essential for progression to specific phases of infection. MTB possesses homologues of DNA repair systems that are found widely in other species of bacteria, such as nucleotide excision repair, base excision repair and repair by homologous recombination. MTB also possesses a system for non-homologous end-joining of DNA breaks, which appears to be widespread in prokaryotes, although its presence is sporadic within different species within a genus. However, MTB does not possess homologues of the typical mismatch repair system that is found in most bacteria. Recent studies have demonstrated that DNA repair genes are expressed differentially at each stage of infection. In the present review, we focus on different DNA repair systems from mycobacteria and identify questions that remain in our understanding of how these systems have an impact upon the infection processes of these important pathogens.

  5. DNA repair in B. subtilis: an inducible dimer-specific W-reactivation system

    International Nuclear Information System (INIS)

    Fields, P.I.; Yasbin, R.E.

    1982-01-01

    The W-reactivation system of Bacillus subtilis can repair pyrimidine dimers in bacteriophage DNA. This inducible repair system can be activated by treatment of the bacteria with uv, alkylating agents, cross-linking agents and gamma irradiation. However, bacteriophage treated with agents other than those that cause pyrimidine dimers to be produced was not repaired by this unique form of W-reactivation. In contrast, the W-reactivation system of Escherichia coli can repair a variety of damages placed in the bacteriophage DNA

  6. 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...

  7. Performance of shcc with bacteria for concrete patch repair

    NARCIS (Netherlands)

    Sierra Beltran, M.G.; Jonkers, H.M.; Schlangen, E.

    2014-01-01

    The overall performance of concrete patch repair systems depends on the durability of and compatibility between the concrete substrate and the repair material. This paper investigates the performance of a new type of SHCC material with embedded bacteria as a repair material. The bacteria are a

  8. Repairable system analysis in presence of covariates and random effects

    International Nuclear Information System (INIS)

    Giorgio, M.; Guida, M.; Pulcini, G.

    2014-01-01

    This paper aims to model the failure pattern of repairable systems in presence of explained and unexplained heterogeneity. The failure pattern of each system is described by a Power Law Process. Part of the heterogeneity among the patterns is explained through the use of a covariate, and the residual unexplained heterogeneity (random effects) is modeled via a joint probability distribution on the PLP parameters. The proposed approach is applied to a real set of failure time data of powertrain systems mounted on 33 buses employed in urban and suburban routes. Moreover, the joint probability distribution on the PLP parameters estimated from the data is used as an informative prior to make Bayesian inference on the future failure process of a generic system belonging to the same population and employed in an urban or suburban route under randomly chosen working conditions. - Highlights: • We describe the failure process of buses powertrain system subject to heterogeneity. • Heterogeneity due to different service types is explained by a covariate. • Random effect is modeled through a joint pdf on failure process parameters. • The powertrain reliability under new future operating conditions is estimated

  9. The Design of Intelligent Repair Welding Mechanism and Relative Control System of Big Gear

    Directory of Open Access Journals (Sweden)

    Hong-Yu LIU

    2014-10-01

    Full Text Available Effective repair of worn big gear has large influence on ensuring safety production and enhancing economic benefits. A kind of intelligent repair welding method was put forward mainly aimed at the big gear restriction conditions of high production cost, long production cycle and high- intensity artificial repair welding work. Big gear repair welding mechanism was designed in this paper. The work principle and part selection of big gear repair welding mechanism was introduced. The three dimensional mode of big gear repair welding mechanism was constructed by Pro/E three dimensional design software. Three dimensional motions can be realized by motor controlling ball screw. According to involute gear feature, the complicated curve motion on curved gear surface can be transformed to linear motion by orientation. By this way, the repair welding on worn gear area can be realized. In the design of big gear repair welding mechanism control system, Siemens S7-200 series hardware was chosen. Siemens STEP7 programming software was chosen as system design tool. The entire repair welding process was simulated by experiment simulation. It provides a kind of practical and feasible method for the intelligent repair welding of big worn gear.

  10. Repair systems with exchangeable items and the longest queue mechanism

    NARCIS (Netherlands)

    Ravid, R.; Boxma, O.J.; Perry, D.

    2013-01-01

    We consider a repair facility consisting of one repairman and two arrival streams of failed items, from bases 1 and 2. The arrival processes are independent Poisson processes, and the repair times are independent and identically exponentially distributed. The item types are exchangeable, and a

  11. Repair systems with exchangeable items and the longest queue mechanism

    NARCIS (Netherlands)

    Ravid, R.; Boxma, O.J.; Perry, D.

    2011-01-01

    We consider a repair facility consisting of one repairman and two arrival streams of failed items, from bases 1 and 2. The arrival processes are independent Poisson processes, and the repair times are independent and identically exponentially distributed. The item types are exchangeable, and a

  12. Life forms employ different repair strategies of repair single- and double strand DNA breaks caused by different qualities of radiation: criticality of RecA mediated repair system

    International Nuclear Information System (INIS)

    Sharan, R.N.

    2013-01-01

    Different qualities of radiation, either through direct or indirect pathway, induce qualitative different spectrum of damages in DNA, which are also different in in vitro and in vivo systems. The single- and double strand breaks of DNA are of special interest as they lead to serious biological consequences. The implications of such damage to DNA and their processing by various inherent repair pathways together decide the fate of the living form

  13. Material reliability of Ni alloy electrodeposition for steam generator tube repair

    International Nuclear Information System (INIS)

    Kim, Dong Jin; Kim, Myong Jin; Kim, Joung Soo; Kim, Hong Pyo

    2007-01-01

    Due to the occasional occurrences of Stress Corrosion Cracking (SCC) in steam generator tubing (Alloy 600), degraded tubes are removed from service by plugging or are repaired for re-use. Since electrodeposition inside a tube dose not entail parent tube deformation, residual stress in the tube can be minimized. In this work, tube restoration via electrodeposition inside a steam generator tubing was performed after developing the following: an anode probe to be installed inside a tube, a degreasing condition to remove dirt and grease, an activation condition for surface oxide elimination, a tightly adhered strike layer forming condition between the electroforming layer and the Alloy 600 tube, and the condition for an electroforming layer. The reliability of the electrodeposited material, with a variation of material properties, was evaluated as a function of the electrodeposit position in the vertical direction of a tube using the developed anode. It has been noted that the variation of the material properties along the electrodeposit length was acceptable in a process margin. To improve the reliability of a material property, the causes of the variation occurrence were presumed, and an attempt to minimize the variation has been made. A Ni alloy electrodeposition process is suggested as a Primary Water Stress Corrosion Cracking (PWSCC) mitigation method for various components, including steam generator tubes. The Ni alloy electrodeposit formed inside a tube by using the installed assembly shows proper material properties as well as an excellent SCC resistance

  14. Integrated analysis of mismatch repair system in malignant astrocytomas.

    Directory of Open Access Journals (Sweden)

    Irene Rodríguez-Hernández

    Full Text Available Malignant astrocytomas are the most aggressive primary brain tumors with a poor prognosis despite optimal treatment. Dysfunction of mismatch repair (MMR system accelerates the accumulation of mutations throughout the genome causing uncontrolled cell growth. The aim of this study was to characterize the MMR system defects that could be involved in malignant astrocytoma pathogenesis. We analyzed protein expression and promoter methylation of MLH1, MSH2 and MSH6 as well as microsatellite instability (MSI and MMR gene mutations in a set of 96 low- and high-grade astrocytomas. Forty-one astrocytomas failed to express at least one MMR protein. Loss of MSH2 expression was more frequent in low-grade astrocytomas. Loss of MLH1 expression was associated with MLH1 promoter hypermethylation and MLH1-93G>A promoter polymorphism. However, MSI was not related with MMR protein expression and only 5% of tumors were MSI-High. Furthermore, the incidence of tumors carrying germline mutations in MMR genes was low and only one glioblastoma was associated with Lynch syndrome. Interestingly, survival analysis identified that tumors lacking MSH6 expression presented longer overall survival in high-grade astrocytoma patients treated only with radiotherapy while MSH6 expression did not modify the prognosis of those patients treated with both radiotherapy and chemotherapy. Our findings suggest that MMR system alterations are a frequent event in malignant astrocytomas and might help to define a subgroup of patients with different outcome.

  15. The Development of Biomimetic Spherical Hydroxyapatite/Polyamide 66 Biocomposites as Bone Repair Materials

    Directory of Open Access Journals (Sweden)

    Xuesong Zhang

    2014-01-01

    Full Text Available A novel biomedical material composed of spherical hydroxyapatite (s-HA and polyamide 66 (PA biocomposite (s-HA/PA was prepared, and its composition, mechanical properties, and cytocompatibility were characterized and evaluated. The results showed that HA distributed uniformly in the s-HA/PA matrix. Strong molecule interactions and chemical bonds were presented between the s-HA and PA in the composites confirmed by IR and XRD. The composite had excellent compressive strength in the range between 95 and 132 MPa, close to that of natural bone. In vitro experiments showed the s-HA/PA composite could improve cell growth, proliferation, and differentiation. Therefore, the developed s-HA/PA composites in this study might be used for tissue engineering and bone repair.

  16. Inspection indications, stress corrosion cracks and repair of process piping in nuclear materials production reactors

    International Nuclear Information System (INIS)

    Louthan, M.R. Jr.; West, S.L.; Nelson, D.Z.

    1991-01-01

    Ultrasonic inspection of Schedule 40 Type 304 stainless steel piping in the process water system of the Savannah River Site reactors has provided indications of discontinuities in less than 10% of the weld heat affected zones. Pipe sections containing significant indications are replaced with Type 304L components. Post removal metallurgical evaluation showed that the indications resulted from stress corrosion cracking in weld heat-affected zones and that the overall weld quality was excellent. The evaluation also revealed weld fusion zone discontinuities such as incomplete penetration, incomplete fusion, inclusions, underfill at weld roots and hot cracks. Service induced extension of these discontinuities was generally not significant although stress corrosion cracking in one weld fusion zone was noted. One set of UT indications was caused by metallurgical discontinuities at the fusion boundary of an extra weld. This extra weld, not apparent on the outer pipe surface, was slightly overlapping and approximately parallel to the weld being inspected. This extra weld was made during a pipe repair, probably associated with initial construction processes. The two nearly parallel welds made accurate assessment of the UT signal difficult. The implications of these observations to the inspection and repair of process water systems of nuclear reactors is discussed

  17. An optimal replacement policy for a repairable system based on its repairman having vacations

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Li [School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092 (China); Xu Jian, E-mail: xujian@tongji.edu.c [School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092 (China)

    2011-07-15

    This paper studies a cold standby repairable system with two different components and one repairman who can take multiple vacations. If there is a component which fails and the repairman is on vacation, the failed component will wait for repair until the repairman is available. In the system, assume that component 1 has priority in use. After repair, component 1 follows a geometric process repair, while component 2 can be repaired as good as new after failures. Under these assumptions, a replacement policy N based on the failed times of component 1 is studied. The system will be replaced if the failure times of component 1 reach N. The explicit expression of the expected cost rate is given, so that the optimal replacement time N{sup *} is determined. Finally, a numerical example is given to illustrate the theoretical results of the model.

  18. Modeling imperfectly repaired system data via grey differential equations with unequal-gapped times

    International Nuclear Information System (INIS)

    Guo Renkuan

    2007-01-01

    In this paper, we argue that grey differential equation models are useful in repairable system modeling. The arguments starts with the review on GM(1,1) model with equal- and unequal-spaced stopping time sequence. In terms of two-stage GM(1,1) filtering, system stopping time can be partitioned into system intrinsic function and repair effect. Furthermore, we propose an approach to use grey differential equation to specify a semi-statistical membership function for system intrinsic function times. Also, we engage an effort to use GM(1,N) model to model system stopping times and the associated operating covariates and propose an unequal-gapped GM(1,N) model for such analysis. Finally, we investigate the GM(1,1)-embed systematic grey equation system modeling of imperfectly repaired system operating data. Practical examples are given in step-by-step manner to illustrate the grey differential equation modeling of repairable system data

  19. Information system revives materials management

    International Nuclear Information System (INIS)

    Hansen, T.

    1995-01-01

    Through a change in philosophy and the development of a new, more efficient information management system, Arizona Public Service Co. (APSW) has, in less than two years, reduced material and service costs by 10 percent. The utility plans to cut these costs form 1993 figures by 25 percent before 2000. The utility is breaking new ground with ongoing implementation of new business processes and the new Materials Logistics Information System (MLIS), which has been co-developed with Texas Instruments Software Division (TISD)

  20. Effect of the Interposition of Calcium Phosphate Materials on Tendon-Bone Healing During Repair of Chronic Rotator Cuff Tear.

    Science.gov (United States)

    Zhao, Song; Peng, Lingjie; Xie, Guoming; Li, Dingfeng; Zhao, Jinzhong; Ning, Congqin

    2014-08-01

    The current nature of tendon-bone healing after rotator cuff (RC) repair is still the formation of granulation tissue at the tendon-bone interface rather than the formation of fibrocartilage, which is the crucial structure in native tendon insertion and can be observed after knee ligament reconstruction. The interposition of calcium phosphate materials has been found to be able to enhance tendon-bone healing in knee ligament reconstruction. However, whether the interposition of these kinds of materials can enhance tendon-bone healing or even change the current nature of tendon-bone healing after RC repair still needs to be explored. The interposition of calcium phosphate materials during RC repair would enhance tendon-bone healing or change its current nature of granulation tissue formation into a more favorable process. Controlled laboratory study. A total of 144 male Sprague-Dawley rats underwent unilateral detachment of the supraspinatus tendon, followed by delayed repair after 3 weeks. The animals were allocated into 1 of 3 groups: (1) repair alone, (2) repair with Ca5(PO4)2SiO4 (CPS) bioceramic interposition, or (3) repair with hydroxyapatite (HA) bioceramic interposition at the tendon-bone interface. Animals were sacrificed at 2, 4, or 8 weeks postoperatively, and microcomputed tomography (micro-CT) was used to quantify the new bone formation at the repair site. New fibrocartilage formation and collagen organization at the tendon-bone interface was evaluated by histomorphometric analysis. Biomechanical testing of the supraspinatus tendon-bone complex was performed. Statistical analysis was performed using 1-way analysis of variance. Significance was set at P repair, CPS bioceramic significantly increased the area of fibrocartilage at the tendon-bone interface compared with the control and HA groups. Moreover, CPS and HA bioceramics had significantly improved collagen organization. Biomechanical tests indicated that the CPS and HA groups have greater ultimate

  1. Single-Molecule Methods for Nucleotide Excision Repair: Building a System to Watch Repair in Real Time.

    Science.gov (United States)

    Kong, Muwen; Beckwitt, Emily C; Springall, Luke; Kad, Neil M; Van Houten, Bennett

    2017-01-01

    Single-molecule approaches to solving biophysical problems are powerful tools that allow static and dynamic real-time observations of specific molecular interactions of interest in the absence of ensemble-averaging effects. Here, we provide detailed protocols for building an experimental system that employs atomic force microscopy and a single-molecule DNA tightrope assay based on oblique angle illumination fluorescence microscopy. Together with approaches for engineering site-specific lesions into DNA substrates, these complementary biophysical techniques are well suited for investigating protein-DNA interactions that involve target-specific DNA-binding proteins, such as those engaged in a variety of DNA repair pathways. In this chapter, we demonstrate the utility of the platform by applying these techniques in the studies of proteins participating in nucleotide excision repair. © 2017 Elsevier Inc. All rights reserved.

  2. Genetic characterization of cells of homocystinuria patients with disrupted DNA repair system

    International Nuclear Information System (INIS)

    Sinel'shchikova, T.A.; L'vova, G.N.; Shoniya, N.N.; Zasukhina, G.D.

    1986-01-01

    Fibroblasts obtained from biopsy material and lymphocytes of patients with homocystinuria were investigated for repair activity according to the following criteria: rejoined DNA breaks, induced by 4-nitroquinoline-1-oxide and γ-radiation; indices of reactivation and induced mutagenesis of smallpox vaccine virus treated with these mutagens. In lymphocytes a defect of DNA repair was observed according to all criteria investigated. During passage of fibroblast cultures, inhibition of repair activity of cells was preserved according to γ-type. Increase in the number of spontaneous and γ-induced mutations of virus was noted according to degree of passage of fibroblasts

  3. Nuclear material statistical accountancy system

    International Nuclear Information System (INIS)

    Argentest, F.; Casilli, T.; Franklin, M.

    1979-01-01

    The statistical accountancy system developed at JRC Ispra is refered as 'NUMSAS', ie Nuclear Material Statistical Accountancy System. The principal feature of NUMSAS is that in addition to an ordinary material balance calcultation, NUMSAS can calculate an estimate of the standard deviation of the measurement error accumulated in the material balance calculation. The purpose of the report is to describe in detail, the statistical model on wich the standard deviation calculation is based; the computational formula which is used by NUMSAS in calculating the standard deviation and the information about nuclear material measurements and the plant measurement system which are required as data for NUMSAS. The material balance records require processing and interpretation before the material balance calculation is begun. The material balance calculation is the last of four phases of data processing undertaken by NUMSAS. Each of these phases is implemented by a different computer program. The activities which are carried out in each phase can be summarised as follows; the pre-processing phase; the selection and up-date phase; the transformation phase, and the computation phase

  4. Availability and mean life time prediction of multistage degraded system with partial repairs

    International Nuclear Information System (INIS)

    Pham, Hoang; Suprasad, A.; Misra, R.B.

    1997-01-01

    In some environments, components might not always fail fully, but can degrade, and there can be multiple stages of degradation. In such cases, the efficiency of the system may decrease. After a certain stage of degradation the efficiency of the system may decrease to an unacceptable limit and can be considered as a total failure. However, the system can fail randomly from any stage. and can be repaired. Further, the repair action cannot bring the system to the good stage, but can make it operational and the failure rate of the system will, therefore, remain the same as before the failure. In this study, we present a model for predicting the reliability, availability, mean life time, and mean time to first failure of multistage degraded systems with partial repairs. In the analysis, state dependent transition rates for the degradation process, as well as repair processes, are considered. A numerical example is provided to illustrate the results

  5. Reliability analysis of repairable safety systems of a reprocessing plant allowing for tolerable system downtimes

    International Nuclear Information System (INIS)

    Schaefer, H.

    1987-01-01

    GRS has been engaged in safety analysises of the German Reprocessing Plant for several years. The development and verification of appropriate reliability analysis methods, the generation of data as well as the search for an adequate structural presentation of the results to form a basis of recommendations for technical or administrative measures or contributions to risk oriented evaluations have been or are in the process of being established. In contrast to NPP-studies, the reliability assessment of safety systems of a reprocessing plant is applied to repairable and often relatively small systems allowing for tolerable system downtimes. A sketch of the diverse cooling systems of a vessel containing a selfheating solution is given. The interruption of the cooling function for about one day might be tolerable before boiling will be reached. This interval is suitable for transfer of the solution to a spare vessel or for repairing the failed components, thus restoring the cooling function

  6. Targeting DNA repair systems in antitubercular drug development.

    Science.gov (United States)

    Minias, Alina; Brzostek, Anna; Dziadek, Jaroslaw

    2018-01-28

    Infections with Mycobacterium tuberculosis, the causative agent of tuberculosis, are difficult to treat using currently available chemotherapeutics. Clinicians agree on the urgent need for novel drugs to treat tuberculosis. In this mini review, we summarize data that prompts the consideration of DNA repair-associated proteins as targets for the development of new antitubercular compounds. We discuss data, including gene expression data, that highlight the importance of DNA repair genes during the pathogenic cycle as well as after exposure to antimicrobials currently in use. Specifically, we report experiments on determining the essentiality of DNA repair-related genes. We report the availability of protein crystal structures and summarize discovered protein inhibitors. Further, we describe phenotypes of available gene mutants of M. tuberculosis and model organisms Mycobacterium bovis and Mycobacterium smegmatis. We summarize experiments regarding the role of DNA repair-related proteins in pathogenesis and virulence performed both in vitro and in vivo during the infection of macrophages and animals. We detail the role of DNA repair genes in acquiring mutations, which influence the rate of drug resistance acquisition. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  7. Degradability of injectable calcium sulfate/mineralized collagen-based bone repair material and its effect on bone tissue regeneration

    International Nuclear Information System (INIS)

    Chen, Zonggang; Kang, Lingzhi; Meng, Qing-Yuan; Liu, Huanye; Wang, Zhaoliang; Guo, Zhongwu; Cui, Fu-Zhai

    2014-01-01

    The nHAC/CSH composite is an injectable bone repair material with controllable injectability and self-setting properties prepared by introducing calcium sulfate hemihydrate (CSH) into mineralized collagen (nHAC). When mixed with water, the nHAC/CSH composites can be transformed into mineralized collagen/calcium sulfate dihydrate (nHAC/CSD) composites. The nHAC/CSD composites have good biocompatibility and osteogenic capability. Considering that the degradation behavior of bone repair material is another important factor for its clinical applications, the degradability of nHAC/CSD composites was studied. The results showed that the degradation ratio of the nHAC/CSD composites with lower nHAC content increased with the L/S ratio increase of injectable materials, but the variety of L/S ratio had no significant effect on the degradation ratio of the nHAC/CSD composites with higher nHAC content. Increasing nHAC content in the composites could slow down the degradation of nHAC/CSD composite. Setting accelerator had no significant effect on the degradability of nHAC/CSD composites. In vivo histological analysis suggests that the degradation rate of materials can match the growth rate of new mandibular bone tissues in the implanted site of rabbit. The regulable degradability of materials resulting from the special prescriptions of injectable nHAC/CSH composites will further improve the workability of nHAC/CSD composites. - Highlights: • The nHAC/CSH composite can be as an injectable bone repair material. • The L/S ratio and nHAC content have a significant effect on material degradability. • The degradability of bone materials can be regulated to match tissue repair. • The regulable degradability will further improve the workability of bone materials

  8. Degradability of injectable calcium sulfate/mineralized collagen-based bone repair material and its effect on bone tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zonggang, E-mail: chenzg@sdu.edu.cn [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Kang, Lingzhi [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Meng, Qing-Yuan [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu, Huanye [Department of Prosthodontics, School of Stomatology, China Medical University, Shenyang 110001 (China); Wang, Zhaoliang [Jinan Military General Hospital of PLA, Jinan 250031 (China); Guo, Zhongwu, E-mail: zwguo@sdu.edu.cn [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Cui, Fu-Zhai, E-mail: cuifz@mail.tsinghua.edu.cn [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2014-12-01

    The nHAC/CSH composite is an injectable bone repair material with controllable injectability and self-setting properties prepared by introducing calcium sulfate hemihydrate (CSH) into mineralized collagen (nHAC). When mixed with water, the nHAC/CSH composites can be transformed into mineralized collagen/calcium sulfate dihydrate (nHAC/CSD) composites. The nHAC/CSD composites have good biocompatibility and osteogenic capability. Considering that the degradation behavior of bone repair material is another important factor for its clinical applications, the degradability of nHAC/CSD composites was studied. The results showed that the degradation ratio of the nHAC/CSD composites with lower nHAC content increased with the L/S ratio increase of injectable materials, but the variety of L/S ratio had no significant effect on the degradation ratio of the nHAC/CSD composites with higher nHAC content. Increasing nHAC content in the composites could slow down the degradation of nHAC/CSD composite. Setting accelerator had no significant effect on the degradability of nHAC/CSD composites. In vivo histological analysis suggests that the degradation rate of materials can match the growth rate of new mandibular bone tissues in the implanted site of rabbit. The regulable degradability of materials resulting from the special prescriptions of injectable nHAC/CSH composites will further improve the workability of nHAC/CSD composites. - Highlights: • The nHAC/CSH composite can be as an injectable bone repair material. • The L/S ratio and nHAC content have a significant effect on material degradability. • The degradability of bone materials can be regulated to match tissue repair. • The regulable degradability will further improve the workability of bone materials.

  9. Strength and Density of Geopolymer Mortar Cured at Ambient Temperature for Use as Repair Material

    Science.gov (United States)

    Warid Wazien, A. Z.; Bakri Abdullah, Mohd Mustafa Al; Abd. Razak, Rafiza; Mohd Remy Rozainy, M. A. Z.; Faheem Mohd Tahir, Muhammad

    2016-06-01

    Geopolymers produced by synthesizing aluminosilicate source materials with an alkaline activator solution promised an excellent properties akin to the existing construction material. This study focused on the effect of various binder to sand ratio on geopolymer mortar properties. Mix design of geopolymer mortar was produced using NaOH concentration of 12 molars, ratio of fly ash/alkaline activator and ratio Na2SiO3/NaOH of 2.0 and 2.5 respectively. Samples subsequently ware cured at ambient temperature. The properties of geopolymer mortar were analysed in term of compressive strength and density at different period which are on the 3rd and 7th day of curing. Experimental results revealed that the addition of sand slightly increase the compressive strength of geopolymer. The optimum compressive strength obtained was up to 31.39 MPa on the 7th day. The density of geopolymer mortar was in the range between 2.0 g/cm3 to 2.23 g/cm3. Based on this findings, the special properties promoted by geopolymer mortar display high potential to be implemented in the field of concrete patch repair.

  10. Specimen preparation for nano-scale investigation of cementitious repair material.

    Science.gov (United States)

    Azarsa, Pejman; Gupta, Rishi

    2018-04-01

    Cementitious Repair Materials (CRMs) in the construction industry have been used for many decades now and has become a very important part of activities in cement world. The performance of some of these CRMs when applied to retrofitting concrete structural elements is also well documented. However, the characterization of some of the CRMs at the micro- and nano level is not fully documented. The first step to studying materials at the microscopic level is to be able to fabricate proper specimens for microscopy. In this study, a special and newly developed class of CRM was selected and fabricated by Focused Ion Beam (FIB) using well-known "Lift-out" technique. The prepared specimen was later examined using various analytical techniques such as energy dispersive x-ray analysis using one of the highest and most stable Scanning Transmission Electron Holography Microscopy (STEHM) around the world. This process enabled understanding of the composition, morphology, and spatial distribution of various phases of the CRM. It was observed that the microstructure consisted of a very fine, compact, and homogenous amorphous structure. X-ray analysis indicated that there was considerable deviation between the Si/Ca ratios for the hydrated product. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Mechatronic systems and materials III

    CERN Document Server

    Gosiewski, Zdzislaw

    2009-01-01

    This very interesting volume is divided into 24 sections; each of which covers, in detail, one aspect of the subject-matter: I. Industrial robots; II. Microrobotics; III. Mobile robots; IV. Teleoperation, telerobotics, teleoperated semi-autonomous systems; V. Sensors and actuators in mechatronics; VI. Control of mechatronic systems; VII. Analysis of vibration and deformation; VIII. Optimization, optimal design; IX. Integrated diagnostics; X. Failure analysis; XI. Tribology in mechatronic systems; XII. Analysis of signals; XIII. Measurement techniques; XIV. Multifunctional and smart materials;

  12. Imaging systems and materials characterization

    International Nuclear Information System (INIS)

    Murr, L.E.

    2009-01-01

    This paper provides a broad background for the historical development and modern applications of light optical metallography, scanning and transmission electron microscopy, field-ion microscopy and several forms of scanning probe microscopes. Numerous case examples illustrating especially synergistic applications of these imaging systems are provided to demonstrate materials characterization especially in the context of structure-property-performance issues which define materials science and engineering

  13. Bond strength of the porcelain repair system to all-ceramic copings and porcelain.

    Science.gov (United States)

    Lee, Sang J; Cheong, Chan Wook; Wright, Robert F; Chang, Brian M

    2014-02-01

    only onto the veneering ceramic surface were not statistically significant from those of 50% surface area of composite bonded onto all-ceramic cores. No statistically significant differences in the bond strength of a porcelain repair system to alumina and zirconia copings were observed. Increasing the surface of veneering ceramics to a porcelain repair system improved the repair material's bond strength. © 2013 by the American College of Prosthodontists.

  14. Reliability analysis of Markov history-dependent repairable systems with neglected failures

    International Nuclear Information System (INIS)

    Du, Shijia; Zeng, Zhiguo; Cui, Lirong; Kang, Rui

    2017-01-01

    Markov history-dependent repairable systems refer to the Markov repairable systems in which some states are changeable and dependent on recent evolutional history of the system. In practice, many Markov history-dependent repairable systems are subjected to neglected failures, i.e., some failures do not affect system performances if they can be repaired promptly. In this paper, we develop a model based on the theory of aggregated stochastic processes to describe the history-dependent behavior and the effect of neglected failures on the Markov history-dependent repairable systems. Based on the developed model, instantaneous and steady-state availabilities are derived to characterize the reliability of the system. Four reliability-related time distributions, i.e., distribution for the k th working period, distribution for the k th failure period, distribution for the real working time in an effective working period, distribution for the neglected failure time in an effective working period, are also derived to provide a more comprehensive description of the system's reliability. Thanks to the power of the theory of aggregated stochastic processes, closed-form expressions are obtained for all the reliability indexes and time distributions. Finally, the developed indexes and analysis methods are demonstrated by a numerical example. - Highlights: • Markovian history-dependent repairable systems with neglected failures is modeled. • Aggregated stochastic processes are used to derive reliability indexes and time distributions. • Closed-form expressions are derived for the considered indexes and distributions.

  15. Experimental Study of Leaching and Penetration of Nitrite ions in Nitrite-type Repair Materials on the Surface of Concrete

    Directory of Open Access Journals (Sweden)

    Masumi Inoue

    2017-01-01

    Full Text Available This study aimed to clarify the leaching properties of nitrite ions in nitrite-type repair materials exposed to rainfall. Repaired concrete specimens were prepared for leaching tests using a lithium nitrite solution, and the amounts of leaching and penetration of nitrite ions were measured under simulated rainfall. The results demonstrated that the amount of leaching could be controlled by using polymer cement paste and mortar surface coatings containing lithium nitrite solution, and by using polymer cement mortar surface coatings following direct lithium nitrite solution coatings. Furthermore, the amount of nitrite ion leaching in all cases was lower than the discharge standard value established by the water pollution control law.

  16. Geomechanical Modeling of CO2 Injection Site to Predict Wellbore Stresses and Strains for the Design of Wellbore Seal Repair Materials

    Science.gov (United States)

    Sobolik, S. R.; Gomez, S. P.; Matteo, E. N.; Stormont, J.

    2015-12-01

    This paper will present the results of large-scale three-dimensional calculations simulating the hydrological-mechanical behavior of a CO2injection reservoir and the resulting effects on wellbore casings and sealant repair materials. A critical aspect of designing effective wellbore seal repair materials is predicting thermo-mechanical perturbations in local stress that can compromise seal integrity. The DOE-NETL project "Wellbore Seal Repair Using Nanocomposite Materials," is interested in the stress-strain history of abandoned wells, as well as changes in local pressure, stress, and temperature conditions that accompany carbon dioxide injection or brine extraction. Two distinct computational models comprise the current modeling effort. The first is a field scale model that uses the stratigraphy, material properties, and injection history from a pilot CO2injection operation in Cranfield, MS to develop a stress-strain history for wellbore locations from 100 to 400 meters from an injection well. The results from the field scale model are used as input to a more detailed model of a wellbore casing. The 3D wellbore model examines the impacts of various loading scenarios on a casing structure. This model has been developed in conjunction with bench-top experiments of an integrated seal system in an idealized scaled wellbore mock-up being used to test candidate seal repair materials. The results from these models will be used to estimate the necessary mechanical properties needed for a successful repair material. This material is based upon work supported by the US Department of Energy (DOE) National Energy Technology Laboratory (NETL) under Grant Number DE-FE0009562. This project is managed and administered by the Storage Division of the NETL and funded by DOE/NETL and cost-sharing partners. This work was funded in part by the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science

  17. On-Orbit Health Monitoring and Repair Assessment of Thermal Protection Systems, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR project delivers On-orbit health MoNItoring and repair assessment of THERMal protection systems (OMNI_THERM). OMNI_THERM features impedance-based...

  18. Self-Repairing Flight Control System for Online Health Monitoring and Recovery, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In this SBIR project, a reliable self-repairing Flight Control System (FCS) will be developed. To achieve this goal, an artificial Neural Network based Sensor...

  19. Evaluation of histological scoring systems for tissue-engineered, repaired and osteoarthritic cartilage

    NARCIS (Netherlands)

    Rutgers, M.; van Pelt, M.J.; Dhert, W.J.A.; Creemers, L.B.; Saris, D.B.F.

    2010-01-01

    Osteoarthritis and Cartilage Volume 18, Issue 1, January 2010, Pages 12-23 -------------------------------------------------------------------------------- Review Evaluation of histological scoring systems for tissue-engineered, repaired and osteoarthritic cartilage M. Rutgers†, M.J.P. van Pelt†,

  20. Systemic EP4 Inhibition Increases Adhesion Formation in a Murine Model of Flexor Tendon Repair.

    Directory of Open Access Journals (Sweden)

    Michael B Geary

    Full Text Available Flexor tendon injuries are a common clinical problem, and repairs are frequently complicated by post-operative adhesions forming between the tendon and surrounding soft tissue. Prostaglandin E2 and the EP4 receptor have been implicated in this process following tendon injury; thus, we hypothesized that inhibiting EP4 after tendon injury would attenuate adhesion formation. A model of flexor tendon laceration and repair was utilized in C57BL/6J female mice to evaluate the effects of EP4 inhibition on adhesion formation and matrix deposition during flexor tendon repair. Systemic EP4 antagonist or vehicle control was given by intraperitoneal injection during the late proliferative phase of healing, and outcomes were analyzed for range of motion, biomechanics, histology, and genetic changes. Repairs treated with an EP4 antagonist demonstrated significant decreases in range of motion with increased resistance to gliding within the first three weeks after injury, suggesting greater adhesion formation. Histologic analysis of the repair site revealed a more robust granulation zone in the EP4 antagonist treated repairs, with early polarization for type III collagen by picrosirius red staining, findings consistent with functional outcomes. RT-PCR analysis demonstrated accelerated peaks in F4/80 and type III collagen (Col3a1 expression in the antagonist group, along with decreases in type I collagen (Col1a1. Mmp9 expression was significantly increased after discontinuing the antagonist, consistent with its role in mediating adhesion formation. Mmp2, which contributes to repair site remodeling, increases steadily between 10 and 28 days post-repair in the EP4 antagonist group, consistent with the increased matrix and granulation zones requiring remodeling in these repairs. These findings suggest that systemic EP4 antagonism leads to increased adhesion formation and matrix deposition during flexor tendon healing. Counter to our hypothesis that EP4 antagonism

  1. Shear Bond Strength of a Novel Porcelain Repair System for ...

    African Journals Online (AJOL)

    2018-04-04

    Apr 4, 2018 ... Each fracture type was examined under a stereomicroscope .... fracture types. Statistical analysis. The normal distribution of data was examined using the Kolmogorov–Smirnov test. Shear bond strength data of repaired CAD/CAM .... adhesives to enamel, dentine, and porcelain surfaces can be compared.

  2. Damage induced by continued corrosion in concrete repair systems

    NARCIS (Netherlands)

    Luckovic, M.; Savija, B.; Schlangen, E.

    2014-01-01

    Corrosion of steel reinforcement is the main cause of deterioration in reinforced concrete structures. After the repair, corrosion of the steel might continue and even accelerate. While the development of the corrosion cell depends on many parameters and is difficult to control, the occurrence of

  3. Failure Modes in Concrete Repair Systems due to Ongoing Corrosion

    NARCIS (Netherlands)

    Lukovic, M.; Šavija, B.; Ye, G.; Schlangen, H.E.J.G.; van Breugel, K.

    2017-01-01

    Corrosion of steel reinforcement is the main cause of deterioration in reinforced concrete structures. It can result in cracking and spalling of the concrete cover. After the damaged cover is repaired, reinforcement corrosion might continue and even accelerate. While the development of the corrosion

  4. Nucleotide excision repair II: From yeast to mammals

    NARCIS (Netherlands)

    J.H.J. Hoeijmakers (Jan)

    1993-01-01

    textabstractAn intricate network of repair systems safeguards the integrity of genetic material, by eliminating DNA lesions induced by numerous environmental and endogenous genotoxic agents. Nucleotide excision repair (NER) is one of the most versatile DNA repair systems. Deficiencies in this

  5. Non-parametric estimation of the availability in a general repairable system

    International Nuclear Information System (INIS)

    Gamiz, M.L.; Roman, Y.

    2008-01-01

    This work deals with repairable systems with unknown failure and repair time distributions. We focus on the estimation of the instantaneous availability, that is, the probability that the system is functioning at a given time, which we consider as the most significant measure for evaluating the effectiveness of a repairable system. The estimation of the availability function is not, in general, an easy task, i.e., analytical techniques are difficult to apply. We propose a smooth estimation of the availability based on kernel estimator of the cumulative distribution functions (CDF) of the failure and repair times, for which the bandwidth parameters are obtained by bootstrap procedures. The consistency properties of the availability estimator are established by using techniques based on the Laplace transform

  6. Non-parametric estimation of the availability in a general repairable system

    Energy Technology Data Exchange (ETDEWEB)

    Gamiz, M.L. [Departamento de Estadistica e I.O., Facultad de Ciencias, Universidad de Granada, Granada 18071 (Spain)], E-mail: mgamiz@ugr.es; Roman, Y. [Departamento de Estadistica e I.O., Facultad de Ciencias, Universidad de Granada, Granada 18071 (Spain)

    2008-08-15

    This work deals with repairable systems with unknown failure and repair time distributions. We focus on the estimation of the instantaneous availability, that is, the probability that the system is functioning at a given time, which we consider as the most significant measure for evaluating the effectiveness of a repairable system. The estimation of the availability function is not, in general, an easy task, i.e., analytical techniques are difficult to apply. We propose a smooth estimation of the availability based on kernel estimator of the cumulative distribution functions (CDF) of the failure and repair times, for which the bandwidth parameters are obtained by bootstrap procedures. The consistency properties of the availability estimator are established by using techniques based on the Laplace transform.

  7. Biomechanical evaluation of potential damage to hernia repair materials due to fixation with helical titanium tacks.

    Science.gov (United States)

    Lerdsirisopon, Sopon; Frisella, Margaret M; Matthews, Brent D; Deeken, Corey R

    2011-12-01

    This study aimed to determine whether the strength and extensibility of hernia repair materials are negatively influenced by the application of helical titanium tacks. This study evaluated 14 meshes including bare polypropylene, macroporous polytetrafluoroethylene, absorbable barrier, partially absorbable mesh, and expanded polytetrafluoroethylene materials. Each mesh provided 15 specimens, which were prepared in 7.5 × 7.5-cm squares. Of these, 5 "undamaged" specimens were subjected to ball-burst testing to determine their biomechanical properties before application of helical titanium tacks (ProTack). To 10 "damaged" specimens 7 tacks were applied 1 cm apart in a 3.5-cm-diameter circle using a tacking force of 25 to 28 N. The tacks were removed from five of the specimens before ball-burst testing and left intact in the remaining five specimens. The application of tacks had no effect on the tensile strength of Dualmesh, ProLite Ultra, Infinit, Ultrapro, C-QUR Lite (6 in.). Most of the meshes did not exhibit significantly different tensile strengths between removal of tacks and tacks left intact. Exceptions included C-QUR, Prolene, Ultrapro, and Bard Soft Mesh, which were weaker with removal of tacks than with tacks left intact during the test. Damage due to the application of helical titanium tacks also caused increased strain at a stress of 16 N/cm for all the meshes except C-QUR Lite (>6 in.) and Physiomesh. Many of the meshes evaluated in this study exhibited damage in the form of reduced tensile strength and increased extensibility after the application of tacks compared with the corresponding "undamaged" meshes. Meshes with smaller interstices and larger filaments were influenced negatively by the application of helical titanium tacks, whereas mesh designs with larger interstices and smaller filaments tended to maintain their baseline mechanical properties.

  8. Control and repair system for radioactive nuclear fuel elements

    International Nuclear Information System (INIS)

    Shallenberger, J.M.; Hornak, L.P.; Desmarchais, W.E.

    1975-01-01

    Irradiated fuel, especially such containing Pu-239, are put in a shielding container for inspection or repair. This container consists of an inner and outer tube of, for example, stainless steel, between which there is a gap filled with water, mineral oil, or polyethylene. At the upper end of the shielding container a rotating sleeve is positioned, by means of a bearing. It contains, for instance, an access opening and an inspection opening which are shielded by means of plexiglass. The access hole is opened only for repair work. In oder to prevent radiation from escaping to the environment during withdrawal and inspection of the fuel elements a second shielding container or shielding tube may be put over the sleeve. (DG/PB) [de

  9. Stochastic behavior of a cold standby system with maximum repair time

    Directory of Open Access Journals (Sweden)

    Ashish Kumar

    2015-09-01

    Full Text Available The main aim of the present paper is to analyze the stochastic behavior of a cold standby system with concept of preventive maintenance, priority and maximum repair time. For this purpose, a stochastic model is developed in which initially one unit is operative and other is kept as cold standby. There is a single server who visits the system immediately as and when required. The server takes the unit under preventive maintenance after a maximum operation time at normal mode if one standby unit is available for operation. If the repair of the failed unit is not possible up to a maximum repair time, failed unit is replaced by new one. The failure time, maximum operation time and maximum repair time distributions of the unit are considered as exponentially distributed while repair and maintenance time distributions are considered as arbitrary. All random variables are statistically independent and repairs are perfect. Various measures of system effectiveness are obtained by using the technique of semi-Markov process and RPT. To highlight the importance of the study numerical results are also obtained for MTSF, availability and profit function.

  10. Supercapacitors materials, systems and applications

    CERN Document Server

    Lu, Max; Frackowiak, Elzbieta

    2013-01-01

    Written by an international group of leading experts from both academia and industry, this is the first comprehensive book on the topic for 10 years. Taking into account the commercial interest in these systems and the scientific and technological developments over the past decade, all important materials and systems are covered, with several chapters devoted to topics of direct industrial relevance.The book starts by providing an introduction to the general principles of electrochemistry, the properties of electrochemical capacitors, and electrochemical characterization techniques. There

  11. Reliability analysis of a repairable k-out-of-n system with some components being suspended when the system is down

    International Nuclear Information System (INIS)

    Li Xiaohu; Zuo, Ming J.; Yam, Richard C.M.

    2006-01-01

    A k-out-of-n system with independent exponential components is investigated. It is assumed that some working components are suspended as soon as the system is down, repair starts immediately when a component fails and repair times are independent and exponentially distributed. Formulas for various reliability indices of the system including mean time between failures, mean working time in a failure-repair cycle, and mean down time in a failure-repair cycle are derived

  12. Control of a maintenance system when failure and repair times have phase type distributions

    Science.gov (United States)

    Decassiamenesesrodrigues, Rita

    1990-09-01

    In the model of machine repair discussed there are M + R identical machines, M operating, and R spares. All machines are independent of one another. When an operating machine fails, it is sent to a single server repair station and immediately replaced by a spare machine, if one is available. The server has two available service types to choose from. There are waiting costs, repair costs, lost production costs, and switch-over costs. The following decision problem is treated: to obtain a stationary policy which determines the service type as a function of the state of the system in order to minimize the long-run average cost when failure and repair times have second-order Coxian distribution. This control problem is represented by a semi-Markov decision process. The policy-iteration algorithm and the value-iteration algorithm are used to obtain the optimal policy. Numerical results are given for these two optimization methods.

  13. Reliability analysis of repairable multi-state system with common bus performance sharing

    International Nuclear Information System (INIS)

    Yu, Huan; Yang, Jun; Mo, Huadong

    2014-01-01

    In this paper, an instantaneous availability model for repairable multi-state system (MSS) with common bus performance sharing is proposed. The repairable MSS consists of some multi-state units and a common bus performance redistribution system. Each unit in the system has several performance levels and must satisfy its individual random demand. A unit can transmit the surplus performance to other units in real time through the common bus performance redistribution system, if it has a performance that exceeds its demand. The entire system fails if the demand of any unit is not satisfied. A new method based on the combination of the stochastic process method and the universal generating function technique is suggested to evaluate the instantaneous availability and the mean instantaneous performance deficiency of the proposed repairable MSS. Two examples are given for applications in the end

  14. Optimal preventive maintenance and repair policies for multi-state systems

    International Nuclear Information System (INIS)

    Sheu, Shey-Huei; Chang, Chin-Chih; Chen, Yen-Luan; George Zhang, Zhe

    2015-01-01

    This paper studies the optimal preventive maintenance (PM) policies for multi-state systems. The scheduled PMs can be either imperfect or perfect type. The improved effective age is utilized to model the effect of an imperfect PM. The system is considered as in a failure state (unacceptable state) once its performance level falls below a given customer demand level. If the system fails before a scheduled PM, it is repaired and becomes operational again. We consider three types of major, minimal, and imperfect repair actions, respectively. The deterioration of the system is assumed to follow a non-homogeneous continuous time Markov process (NHCTMP) with finite state space. A recursive approach is proposed to efficiently compute the time-dependent distribution of the multi-state system. For each repair type, we find the optimal PM schedule that minimizes the average cost rate. The main implication of our results is that in determining the optimal scheduled PM, choosing the right repair type will significantly improve the efficiency of the system maintenance. Thus PM and repair decisions must be made jointly to achieve the best performance

  15. Repair system and mitomycin mutagenesis in Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Otsuji, N; Murayama, I [Kyushu Univ., Fukuoka (Japan). Faculty of Pharmaceutical Sciences

    1974-03-01

    Ultraviolet light sensitive mutants of E. coli defective at the uvrA, uvrB or uvrC locus showed increased sensitivity to the lethal effects of monofunctional mitomycin, 7-methoxymitosene (7-MMT) or decarbamoyl mitomycin C (DCMTC), as well as mitomycin C (MTC). (1) Treatment of wild type bacteria with these monofunctional mitomycins resulted in the production of single-strand breaks in DNA, which were repaired upon incubation in a growth medium. Such breaks in DNA were not produced in the UvrA and the UvrB mutants. In the UvrC mutant, single-strand breaks were produced by 7-MMT or by DCMTC, but these breaks were not repaired upon incubation. (2) Exposure of E. coli to MTC caused cross-linkage between DNA strands, which converted to a normally denaturable form during further incubation after treatment. This was not occurred in the UvrB strain. In the UvrC mutant, a portion of the cross-links was removed upon incubation. (3) 7-MMT and DCMTC induced mutation in UV sensitive UvrB and UvrC mutants with much higher frequency than in wild type bacteria, while MTC did not induce mutation in these Uvr-strains.

  16. Repair system and mitomycin mutagenesis in Escherichia coli

    International Nuclear Information System (INIS)

    Otsuji, Nozomu; Murayama, Ichiko

    1974-01-01

    Ultraviolet light sensitive mutants of E. coli defective at the uvrA, uvrB or uvrC locus showed increased sensitivity to the lethal effects of monofunctional mitomycin, 7-methoxymitosene (7-MMT) or decarbamoyl mitomycin C (DCMTC), as well as mitomycin C (MTC). (1) Treatment of wild type bacteria with these monofunctional mitomycins resulted in the production of single-strand breaks in DNA, which were repaired upon incubation in a growth medium. Such breaks in DNA were not produced in the UvrA and the UvrB mutants. In the UvrC mutant, single-strand breaks were produced by 7-MMT or by DCMTC, but these breaks were not repaired upon incubation. (2) Exposure of E. coli to MTC caused cross-linkage between DNA strands, which converted to a normally denaturable form during further incubation after treatment. This was not occurred in the UvrB strain. In the UvrC mutant, a portion of the cross-links was removed upon incubation. (3) 7-MMT and DCMTC induced mutation in UV sensitive UvrB and UvrC mutants with much higher frequency than in wild type bacteria, while MTC did not induce mutation in these Uvr-strains. (author)

  17. Material control system simulator program reference manual

    Energy Technology Data Exchange (ETDEWEB)

    Hollstien, R.B.

    1978-01-24

    A description is presented of a Material Control System Simulator (MCSS) program for determination of material accounting uncertainty and system response to particular adversary action sequences that constitute plausible material diversion attempts. The program is intended for use in situations where randomness, uncertainty, or interaction of adversary actions and material control system components make it difficult to assess safeguards effectiveness against particular material diversion attempts. Although MCSS may be used independently in the design or analysis of material handling and processing systems, it has been tailored toward the determination of material accountability and the response of material control systems to adversary action sequences.

  18. Material control system simulator program reference manual

    International Nuclear Information System (INIS)

    Hollstien, R.B.

    1978-01-01

    A description is presented of a Material Control System Simulator (MCSS) program for determination of material accounting uncertainty and system response to particular adversary action sequences that constitute plausible material diversion attempts. The program is intended for use in situations where randomness, uncertainty, or interaction of adversary actions and material control system components make it difficult to assess safeguards effectiveness against particular material diversion attempts. Although MCSS may be used independently in the design or analysis of material handling and processing systems, it has been tailored toward the determination of material accountability and the response of material control systems to adversary action sequences

  19. Long-term behaviors of phosphate-based rapid repairing material for concrete shafts in coal mines.

    Science.gov (United States)

    Lei, Feng; Zhen-Ya, Zhang; Xiao-Dong, Wen; Chao, Xin; Dong-Yuan, Hu

    2018-04-01

    Concrete structures in shaft linings are apt to deteriorate prematurely and therefore prompt restoration is required. In considering this, desulphurization fly ash and machine-made tuff sand are employed to fabricate a phosphate-based rapid repairing material. The long-term efficiency of the material is evaluated based on combined factors, so drying shrinkage, interfacial bonding strength, corrosion resistance, and combustibility of the specimens are tested and researched in this paper. Experimental results showed that, under a dry circumstance, the material goes through a minor expansion at an early stage. It goes into a stage of rapid contraction after one day and a stable contraction after seven days. After 28 days, the total deformation is 67 micro-strains. On the other hand, the fabricated material manifests an excellent mechanical property. The one hour bending strength and compressive strength were 9.2 MPa and 32.6 MPa, respectively. A long-term mine water flushing simulation demonstrates that only 10% bending strength is lost and the corrosion resistance coefficient stays above 0.8, so a very good corrosion resistance is thus achieved. What is more, this repairing material retains its stability even at a high temperature of 1000°C, revealing its good thermo-stability. All these prominent properties make it a good prospective material for real restoration applications.

  20. Self-repair in a Bidirectionally Coupled Astrocyte-Neuron (AN System based on Retrograde Signaling

    Directory of Open Access Journals (Sweden)

    John eWade

    2012-09-01

    Full Text Available In this paper we demonstrate that retrograde signaling via astrocytes may underpin self-repair in the brain. Faults manifest themselves in silent or near silent neurons caused by low transmission probability synapses; the enhancement of the transmission probability of a healthy neighbouring synapse by retrograde signaling can enhance the transmission probability of the faulty synapse (repair. Our model of self-repair is based on recent research showing that retrograde signaling via astrocytes can increase the probability of neurotransmitter release at damaged or low transmission probability synapses. The model demonstrates that astrocytes are capable of bidirectional communication with neurons which leads to modulation of synaptic activity, and that indirect signaling through retrograde messengers such as endocannabinoids leads to modulation of synaptic transmission probability. Although our model operates at the level of cells, it provides a new research direction on brain-like self-repair which can be extended to networks of astrocytes and neurons. It also provides a biologically inspired basis for developing highly adaptive, distributed computing systems that can, at fine levels of granularity, fault detect, diagnose and self-repair autonomously, without the traditional constraint of a central fault detect/repair unit.

  1. Fieldable Nuclear Material Identification System

    International Nuclear Information System (INIS)

    Radle, James E.; Archer, Daniel E.; Carter, Robert J.; Mullens, James Allen; Mihalczo, John T.; Britton, Charles L. Jr.; Lind, Randall F.; Wright, Michael C.

    2010-01-01

    The Fieldable Nuclear Material Identification System (FNMIS), funded by the NA-241 Office of Dismantlement and Transparency, provides information to determine the material attributes and identity of heavily shielded nuclear objects. This information will provide future treaty participants with verifiable information required by the treaty regime. The neutron interrogation technology uses a combination of information from induced fission neutron radiation and transmitted neutron imaging information to provide high confidence that the shielded item is consistent with the host's declaration. The combination of material identification information and the shape and configuration of the item are very difficult to spoof. When used at various points in the warhead dismantlement sequence, the information complimented by tags and seals can be used to track subassembly and piece part information as the disassembly occurs. The neutron transmission imaging has been developed during the last seven years and the signature analysis over the last several decades. The FNMIS is the culmination of the effort to put the technology in a usable configuration for potential treaty verification purposes.

  2. Performance evaluation of multi-state degraded systems with minimal repairs and imperfect preventive maintenance

    International Nuclear Information System (INIS)

    Soro, Isaac W.; Nourelfath, Mustapha; Ait-Kadi, Daoud

    2010-01-01

    In this paper, we develop a model for evaluating the availability, the production rate and the reliability function of multi-state degraded systems subjected to minimal repairs and imperfect preventive maintenance. The status of the system is considered to degrade with use. These degradations may lead to decrease in the system efficiency. It is assumed that the system can consecutively degrade into several discrete states, which are characterized by different performance rates, ranging from perfect functioning to complete failure. The latter is observed when the degradation level reaches a certain critical threshold such as the system efficiency may decrease to an unacceptable limit. In addition, the system can fail randomly from any operational or acceptable state and can be repaired. This repair action brings the system to its previous operational state without affecting its failure rate (i.e., minimal repair). The used preventive maintenance policy suggests that if the system reaches the last acceptable degraded state, it is brought back to one of the states with higher efficiency. Considering customer demand as constant, the system is modeled as a continuous-time Markov process to assess its instantaneous and stationary performance measures. A numerical example is given to illustrate the proposed model.

  3. Effects of caffeine or maternal repair systems in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Osgood, C.; Zimmering, S.

    1979-01-01

    Drosophila melanogaster females were treated with 1% caffeine, mated with X-rayed males and the frequencies of induced sex-chromosome loss, translocations between the major autosomes and between the Y-chromosome and the major autosomes determined. In a reversal of the results obtained previously with 0.2% caffeine by Mendelson and Sobels, treatment of females with 1% caffeine led to a decrease in sex-chromosome loss, confirming preliminary data of Zimmering and Osgood and in increase in autosome-autosome translocations. It is suggested that the higher concentration of caffeine inhibits replication permitting more time available for chromosome-type restitutions by means of caffeine-insensitive repair mechanisms. In contrast with results for autosome-autosome translocation, the fequency of Y-autosome translocations was depressed below controls suggesting an isolation (by any one of several means) of Y-chromosome breaks from those in the autosomes. (Auth.)

  4. Bayesian analysis of repairable systems showing a bounded failure intensity

    International Nuclear Information System (INIS)

    Guida, Maurizio; Pulcini, Gianpaolo

    2006-01-01

    The failure pattern of repairable mechanical equipment subject to deterioration phenomena sometimes shows a finite bound for the increasing failure intensity. A non-homogeneous Poisson process with bounded increasing failure intensity is then illustrated and its characteristics are discussed. A Bayesian procedure, based on prior information on model-free quantities, is developed in order to allow technical information on the failure process to be incorporated into the inferential procedure and to improve the inference accuracy. Posterior estimation of the model-free quantities and of other quantities of interest (such as the optimal replacement interval) is provided, as well as prediction on the waiting time to the next failure and on the number of failures in a future time interval is given. Finally, numerical examples are given to illustrate the proposed inferential procedure

  5. Injectable calcium sulfate/mineralized collagen-based bone repair materials with regulable self-setting properties.

    Science.gov (United States)

    Chen, Zonggang; Liu, Huanye; Liu, Xi; Cui, Fu-Zhai

    2011-12-15

    An injectable and self-setting bone repair materials (nano-hydroxyapatite/collagen/calcium sulfate hemihydrate, nHAC/CSH) was developed in this study. The nano-hydroxyapatite/collagen (nHAC) composite, which is the mineralized fibril by self-assembly of nano-hydrocyapatite and collagen, has the same features as natural bone in both main hierarchical microstructure and composition. It is a bioactive osteoconductor due to its high level of biocompatibility and appropriate degradation rate. However, this material lacks handling characteristics because of its particle or solid-preformed block shape. Herein, calcium sulfate hemihydrate (CSH) was introduced into nHAC to prepare an injectable and self-setting in situ bone repair materials. The morphology of materials was observed using SEM. Most important and interesting of all, calcium sulfate dihydrate (CSD), which is not only the reactant of preparing CSH but also the final solidified product of CSH, was introduced into nHAC as setting accelerator to regulate self-setting properties of injectable nHAC/CSH composite, and thus the self-setting time of nHAC/CSH composite can be regulated from more than 100 min to about 30 min and even less than 20 min by adding various amount of setting accelerator. The compressive properties of bone graft substitute after final setting are similar to those of cancellous bone. CSD as an excellent setting accelerator has no significant effect on the mechanical property and degradability of bone repair materials. In vitro biocompatibility and in vivo histology studies demonstrated that the nHAC/CSH composite could provide more adequate stimulus for cell adhesion and proliferation, embodying favorable cell biocompatibility and a strong ability to accelerate bone formation. It can offer a satisfactory biological environment for growing new bone in the implants and for stimulating bone formation. Copyright © 2011 Wiley Periodicals, Inc.

  6. The role of the bacterial mismatch repair system in SOS-induced mutagenesis: a theoretical background

    International Nuclear Information System (INIS)

    Belov, O.V.; Kapralov, M.I.; Chuluunbaatar, O.; Sweilam, N.H.

    2012-01-01

    A theoretical study is performed of the possible role of the methyl-directed mismatch repair system in the ultraviolet-induced mutagenesis of Escherichia coli bacterial cells. For this purpose, a mathematical model of the bacterial mismatch repair system is developed. Within this model, the key pathways of this type of repair are simulated on the basis of modern experimental data related to its mechanisms. Here we have modelled in detail five main pathways of DNA misincorporation removal with different DNA exonucleases. Using our calculations, we have tested the hypothesis that the bacterial mismatch repair system is responsible for the removal of the nucleotides misincorporated by DNA polymerase V (the UmuD' 2 C complex) during ultraviolet-induced SOS response. For the theoretical analysis of the mutation frequency, we have combined the proposed mathematical approach with the model of SOS-induced mutagenesis in the E.coli bacterial cell developed earlier. Our calculations support the hypothesis that methyl-directed mismatch repair influences the mutagenic effect of ultraviolet radiation

  7. The bases for optimisation of scheduled repairs and tests of safety systems to improve the NPP productive efficiency

    International Nuclear Information System (INIS)

    Bilej, D.V.; Vasil'chenko, S.V.; Vlasenko, N.I.; Vasil'chenko, V.N.; Skalozubov, V.I.

    2004-01-01

    In the frames of risk-informed approaches the paper proposed the theoretical bases for methods of optimisation of scheduled repairs and tests of safety systems at nuclear power plants. The optimisation criterion is the objective risk function minimising. This function depends on the scheduled repairs/tests periodicity and the allowed time to bring the system channel to a state of non-operability. The main optimisation direct is to reduce the repair time with the purpose of enhancement of productive efficiency

  8. Evaluation of the sealing ability of bone cement as furcation perforation repair material when compared with mineral trioxide aggregate and calcium phosphate cement: An in-vitro study

    Directory of Open Access Journals (Sweden)

    Rashmi Chordiya

    2010-01-01

    Full Text Available Aim: This study was undertaken to compare the sealing ability of bone cement as furcation perforation repair material when compared with mineral trioxide aggregate and calcium phosphate cement. Materials and Methods: A total of 70 sound mandibular molars were selected for this study. The sample teeth were randomly divided into five groups: group I - n=20, perforation repair material used, mineral trioxide aggregate; group II - n=20, perforation repair material used, calcium phosphate cement; group III - n=20, perforation repair material used, bone cement; group IV - positive control, n=5, the furcation were not repaired with any material; group V - negative control, n=5, furcation area intact, no perforation done. The teeth were immersed in silver nitrate solution for 2 hours and then rinsed with photographic developer solution for 6 hours. They were then sectioned in a longitudinal direction and examined under a stereomicroscope. In each section the actual values of dye leakage were calculated from outer margins of perforation to the level of pulpal floor and were then subjected to statistical analysis. Results: An unpaired ′t′ test revealed that different groups exhibited significantly different dye penetrations (P<0.01. Conclusion: Furcation perforation repaired with MTA showed minimum microleakage (mean 54.5%, calcium phosphate cement showed maximum microleakage (100%, and bone cement showed moderate dye leakage (87.8%.

  9. RESTART simulation of non-Markov consecutive-k-out-of-n: F repairable systems

    International Nuclear Information System (INIS)

    Villen-Altamirano, Jose

    2010-01-01

    The reliability of consecutive-k-out-of-n: F repairable systems and (k-1)-step Markov dependence is studied. The model analyzed in this paper is more general than those of previous studies given that repair time and component lifetimes are random variables that follow a general distribution. The system has one repair service which adopts a priority repair rule based on system failure risk. Since crude simulation has proved to be inefficient for highly dependable systems, the RESTART method was used for the estimation of steady-state unavailability, MTBF and unreliability. Probabilities up to the order of 10 -16 have been accurately estimated with little computational effort. In this method, a number of simulation retrials are performed when the process enters regions of the state space where the chance of occurrence of a rare event (e.g., a system failure) is higher. The main difficulty for the application of this method is to find a suitable function, called the importance function, to define the regions. Given the simplicity involved in changing some model assumptions with RESTART, the importance function used in this paper could be useful for dependability estimation of many systems.

  10. Intelligent material systems - The dawn of a new materials age

    International Nuclear Information System (INIS)

    Rogers, C.A.

    1993-01-01

    The intelligent material system solution to such engineering problems as the design of a robotic arm borrows directly from biological analogs; materials that behave much as muscles do during contraction can be employed as induced strain actuators which work against the intrinsic structural impedance of the component. Unlike actual human arms, which are jointed, the intelligent structure may be a continuum. The adaptation of structural impedance may be regarded as the most fundamental and consequential concept in the field of intelligent material systems

  11. Material control system simulator user's manual

    International Nuclear Information System (INIS)

    Hollstien, R.B.

    1978-01-01

    This report describes the use of a Material Control System Simulator (MCSS) program for determination of material accounting uncertainty and system response to particular adversary action sequences that constitute plausible material diversion attempts. The program is intended for use in situations where randomness, uncertainty, or interaction of adversary actions and material control system components make it difficult to assess safeguards effectiveness against particular material diversion attempts

  12. Materials for spaceborne laser systems

    International Nuclear Information System (INIS)

    Gusarov, A.

    2006-01-01

    Advanced laser systems are attracting a growing interest for space missions, in particular for LIDAR (LIght Detection And Ranging) applications. An important issue for the LIDARs is the very strict requirements on the optical performance and more specifically the need for a high optical output power combined with a nearly perfect output beam quality. These features are traditionally in conflict with each other. Thermally induced phase distortions indeed corrupt the beam quality of high-power solid-state lasers and it becomes increasingly difficult to maintain a good beam quality while increasing the output power. A possible solution of the problem is to use the optical phase conjugation, which provides a method to dynamically correct for those aberrations. A process by which phase-conjugated waves can be generated is the SBS (stimulated Brillouin scattering). SBS mirrors commonly used in terrestrial application are based on liquids or gases, which are not 'space-friendly' and often toxic. The solid-state alternative seems the most appropriate for space. Such PCMs (Phase-Conjugating Mirrors) have been the subject of many research efforts in recent years and a significant progress in improving their characteristics has been achieved. However, the issue of space qualification remains open. To address it, the European Space Agency initiated in 2004 the research project named Solid-State Phase Conjugation, Radiation Testing and Evaluation for Core Laser Technologies with the TRT (Thales Research and Technology), France, as the prime contractor, and the CSL (Centre Spatial de Liege) and SCKCEN as the subcontractors. The project is to be completed in 2006. To qualify a PCM for a spaceborne laser system, one has to address a number of specific issues. Such a component must be mechanically rugged to sustain vibrations during the launch phase, provide a low out-gassing to prevent optical surfaces contamination in vacuum, be highly reliable to operate properly without

  13. Self repairing composites for drone air vehicles

    Science.gov (United States)

    Dry, Carolyn

    2015-04-01

    The objective of this effort was to demonstrate the feasibility of impact-initiated delivery of repair chemicals through hollow fiber architectures embedded within graphite fiber reinforced polymer matrix composites, representative of advanced drone aircraft component material systems. Self-repairing structures through coupon and elements were demonstrated, and evaluated.

  14. Repair mechanisms inducible to the DNA in I.M.M.S. biological systems; Mecanismos de reparacion inducible del ADN en sistemas biologicos I.M.M.S

    Energy Technology Data Exchange (ETDEWEB)

    Guzman, J; Arceo, C; Cortinas, C; Rosa, M.E. De la; Olvera, O; Cruces, M; Pimentel, E

    1990-03-15

    Given the characteristics of the MMS and the relative antecedents to the repair mechanisms in eucariontes are sought to determine the effect of the MMS on the genetic material and their repair in Drosophila melanogaster. (Author)

  15. [Studies on the repair of damaged DNA in bacteriophage, bacterial and mammalian systems]: Final report

    International Nuclear Information System (INIS)

    Friedberg, E.C.

    1987-08-01

    This study sought to exploit the use of uv radiation as a source of genomic damage. We explored the molecular mechanism of the repair of DNA damage at a number of different levels of biological organization, by investigating bacteriophage, bacterial, yeast and mammalian cells. Not only have observations obtained in one biological system suggested specific experimental approaches in others, but we have also learned that some biochemical pathways for DNA repair are unique to specific organisms. Our studies are summarized in terms of 4 major areas of research activity that span the past 16 years. 86 refs

  16. Prediction of Repair Work Duration for Gas Transport Systems Based on Small Data Samples

    DEFF Research Database (Denmark)

    Lesnykh, Valery; Litvin, Yuri; Kozin, Igor

    2016-01-01

    Prediction of the duration of a repair and maintenance project of a gas transport system is an important part of planning activities. There exist numerous sources of uncertainties that may result in time overruns possibly leading to multiple negative consequences. Our experience in planning...... this work suggests that accepting the stochastic nature of the project duration is a constructive step towards the preparedness to contingencies and defining penalties for repair companies. To support this approach, one needs to construct probability distributions of the durations of the projects...

  17. A new technique for repair of a dislocated sternoclavicular joint using a sternal tension cable system.

    Science.gov (United States)

    Janson, Jacques T; Rossouw, Gawie J

    2013-02-01

    An unstable anterior or posterior sternoclavicular joint dislocation can cause severe morbidity with poor shoulder movement and strength. These dislocations need to be repaired, which can be challenging. Many different procedures have been described to obtain a stable joint fixation with varying results. We report a new technique for repairing a sternoclavicular joint dislocation by using a figure-of-eight sternal cable system. This procedure is relatively simple and reproducible to create a stable and functional sternoclavicular joint. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  18. Development of Laboratory Testing Criteria for Evaluating Cementitious, Rapid-Setting Pavement Repair Materials

    Science.gov (United States)

    2011-04-01

    Squadron, Engineer (RED HORSE) squadrons, and Prime BEEF (Base Engineer Emergency Force) units. Additional users of this report include Army, Navy...approved AFRL 10 2007 PavePatch 3000 Conspec Co. Fail Not approved AFRL 11 2007 Premium Patch 200 Pre-Blend Products, Inc. Fail Expeditionary spall...damaged pavement. A small patch is not limited to spall repair as it may replace pavement damaged within a slab, such as a small utility cut . Large

  19. Injecting a liquid bacteria-based repair system to make porous network conrete healed

    NARCIS (Netherlands)

    Sangadji, S.; Wiktor, V.A.C.; Jonkers, H.M.; Schlangen, H.E.J.G.

    2013-01-01

    Bacteria induced calcite precipitation has been proven to be effective in making concrete structure self-healing. In Microlab TU Delft, the concept has been enhanced by developing a liquid bacteria-based concrete repair system. The solution contains calcite precipitating bacteria, nutrients and

  20. Designing Biomimetic, Dissipative Material Systems

    Energy Technology Data Exchange (ETDEWEB)

    Balazs, Anna C. [Univ. of Pittsburgh, PA (United States). Chemical Engineering Dept.; Whitesides, George M. [Harvard Univ., Cambridge, MA (United States). Dept. of Chemistry and Chemical Biology; Brinker, C. Jeffrey [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Chemical and Nuclear Engineering. Dept. of Chemistry. Dept. of Molecular Genetics and Microbiology. Center for Micro-Engineered Materials; Aranson, Igor S. [UChicago, LLC., Argonne, IL (United States); Chaikin, Paul [New York Univ. (NYU), NY (United States). Dept. of Physics; Dogic, Zvonimir [Brandeis Univ., Waltham, MA (United States). Dept. of Physics; Glotzer, Sharon [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Chemical Engineering. Dept. of Materials Science and Engineering. Dept. of Macromolecular Science and Engineering Physics; Hammer, Daniel [Univ. of Pennsylvania, Philadelphia, PA (United States). School of Engineering and Applied Science; Irvine, Darrell [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Materials Science and Engineering and Biological Engineering; Little, Steven R. [Univ. of Pittsburgh, PA (United States). Chemical Engineering Dept.; Olvera de la Cruz, Monica [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering; Parikh, Atul N. [Univ. of California, Davis, CA (United States). Dept. of Biomedical Engineering. Dept. of Chemical Engineering and Materials Science; Stupp, Samuel [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering. Dept. of Chemistry. Dept. of Medicine. Dept. of Biomedical Engineering; Szostak, Jack [Harvard Univ., Cambridge, MA (United States). Dept. of Chemistry and Chemical Biology

    2016-01-21

    Throughout human history, new materials have been the foundation of transformative technologies: from bronze, paper, and ceramics to steel, silicon, and polymers, each material has enabled far-reaching advances. Today, another new class of materials is emerging—one with both the potential to provide radically new functions and to challenge our notion of what constitutes a “material”. These materials would harvest, transduce, or dissipate energy to perform autonomous, dynamic functions that mimic the behaviors of living organisms. Herein, we discuss the challenges and benefits of creating “dissipative” materials that can potentially blur the boundaries between living and non-living matter.

  1. Six types Monte Carlo for estimating the current unavailability of Markov system with dependent repair

    International Nuclear Information System (INIS)

    Xiao Gang; Li Zhizhong

    2004-01-01

    Based on integral equaiton describing the life-history of Markov system, six types of estimators of the current unavailability of Markov system with dependent repair are propounded. Combining with the biased sampling of state transition time of system, six types of Monte Carlo for estimating the current unavailability are given. Two numerical examples are given to deal with the variances and efficiencies of the six types of Monte Carlo methods. (authors)

  2. An artificial neural network for modeling reliability, availability and maintainability of a repairable system

    International Nuclear Information System (INIS)

    Rajpal, P.S.; Shishodia, K.S.; Sekhon, G.S.

    2006-01-01

    The paper explores the application of artificial neural networks to model the behaviour of a complex, repairable system. A composite measure of reliability, availability and maintainability parameters has been proposed for measuring the system performance. The artificial neural network has been trained using past data of a helicopter transportation facility. It is used to simulate behaviour of the facility under various constraints. The insights obtained from results of simulation are useful in formulating strategies for optimal operation of the system

  3. Materials Selection for Aerospace Systems

    Science.gov (United States)

    Arnold, Steven M.; Cebon, David; Ashby, Mike

    2012-01-01

    A systematic design-oriented, five-step approach to material selection is described: 1) establishing design requirements, 2) material screening, 3) ranking, 4) researching specific candidates and 5) applying specific cultural constraints to the selection process. At the core of this approach is the definition performance indices (i.e., particular combinations of material properties that embody the performance of a given component) in conjunction with material property charts. These material selection charts, which plot one property against another, are introduced and shown to provide a powerful graphical environment wherein one can apply and analyze quantitative selection criteria, such as those captured in performance indices, and make trade-offs between conflicting objectives. Finding a material with a high value of these indices maximizes the performance of the component. Two specific examples pertaining to aerospace (engine blades and pressure vessels) are examined, both at room temperature and elevated temperature (where time-dependent effects are important) to demonstrate the methodology. The discussion then turns to engineered/hybrid materials and how these can be effectively tailored to fill in holes in the material property space, so as to enable innovation and increases in performance as compared to monolithic materials. Finally, a brief discussion is presented on managing the data needed for materials selection, including collection, analysis, deployment, and maintenance issues.

  4. Reference material systems: a sourcebook for material assessment

    Energy Technology Data Exchange (ETDEWEB)

    Bhagat, N. (ed.)

    1976-12-01

    A reference set of data related to material systems and a framework for carrying out the material technologies assessment are presented. While the bulk of renewables have been considered in this report, the nonrenewable materials dealt with here include structural materials only, such as steel, aluminum, cement and concrete, and bricks. The complete data set is supposed to include material flows, energy requirements, capital and labor inputs, and environmental effects for each process that a resource must go through to become a useful material for an end use. Although effort has been made to obtain as much information as possible, considerable gaps in data, apparent throughout this report, could not be avoided. A new material technology can be evaluated by substituting that technology for appropriate elements of the reference materials system and calculating the net change in material resource, energy, capital and labor requirements, and environmental impacts. This combination of information thus serves as a means of evaluating the potential benefits to be gained by research in various material technologies.

  5. Motorcycle Repair.

    Science.gov (United States)

    Hein, Jim; Bundy, Mike

    This motorcycle repair curriculum guide contains the following ten areas of study: brake systems, clutches, constant mesh transmissions, final drives, suspension, mechanical starting mechanisms, electrical systems, fuel systems, lubrication systems, and overhead camshafts. Each area consists of one or more units of instruction. Each instructional…

  6. Present status of DNA repair mechanisms in uv irradiated yeast taken as a model eukaryotic system

    International Nuclear Information System (INIS)

    Moustacchi, E.; Waters, R.; Heude, M.; Chanet, R.

    1975-01-01

    The repair mechanisms of altered DNA are generally less well understood for eukaryotes than they are for prokaryotes and bacteriophages. For mammalian cell lines cultured in vitro the specific labelling of DNA has allowed the biochemical analysis of some of the steps of the repair processes whereas the determination of their genetic controls is, with a few exceptions, obviously difficult. On the other hand, with fungi and more specifically with yeast taken as a model unicellular eukaryotic system, the genetic approach has been extensively explored: radiosensitive mutants are readily detected and genetically analyzed, double and multiple mutants can be constructed and from their responses to irradiation the number of repair pathways involved can be suggested. The lack of thymidine kinase in these organisms has hampered for a certain time the biochemical analysis of repair. However, the recent isolation of yeast strains capable of taking up and incorporating thymidine 5'-monophosphate into their DNA opens new possibilities for the future. In spite of this difficulty, attempts to measure the induction and removal of uv-induced pyrimidine dimers were performed by several groups during the last three years. The two main repair pathways described for E. coli, i.e., the excision-resynthesis and post-replicative recombinational repair pathways, do exist in yeast. The existence of the former pathway is supported not only by indirect evidence but also by biochemical analysis. The rad 1 and rad 2 mutants for instance have been shown to be blocked in the excision of uv-induced pyrimidine dimers. Other loci are epistatic to rad 1 and rad 2 (rad 3 , rad 4 ) and are likely to act on this excision pathway. The genetic control of the mitochondrial response to a uv treatment involves nuclear genes and mitochondrial determinants

  7. Minicomputer based, controlled materials information system

    International Nuclear Information System (INIS)

    Roberts, N.; Jessen, T.; Meadors, O.; Seibel, D.

    1976-01-01

    The LLL, Materials Management Group and Data Processing Services have developed a transaction-oriented, minicomputer system for the management of the Laboratory's controlled materials. The system consists of a multi-vendor hardware system designed for ease of operation, maximum reliability, and quick response and the requirements imposed on the hardware and software systems are discussed

  8. Statistical evaluation of failures and repairs of the V-1 measuring and control system

    International Nuclear Information System (INIS)

    Laurinec, R.; Korec, J.; Mitosinka, J.; Zarnovican, V.

    1984-01-01

    A failure record card system was introduced for evaluating the reliability of the measurement and control equipment of the V-1 nuclear power plant. The SPU-800 microcomputer system is used for recording data on magnetic tape and their transmission to the central data processing department. The data are used for evaluating the reliability of components and circuits and a selection is made of the most failure-prone components, and the causes of failures are evaluated as are failure identification, repair and causes of outages. The system provides monthly, annual and total assessment data since the system was commissioned. The results of the statistical evaluation of failures are used for planning preventive maintenance and for determining optimal repair intervals. (E.S.)

  9. [The correlations between aging of the human body, oxidative stress and reduced efficiency of repair systems].

    Science.gov (United States)

    Michalak, Aleksandra; Krzeszowiak, Jakub; Markiewicz-Górka, Iwona

    2014-12-15

    The article presents an current knowledge overview about the importance of oxidative stress and reduced efficiency of repair processes during the aging process of the human body. Oxidative damage to cellular macromolecules (proteins, lipids, nucleic acids), are formed under the influence of reactive oxygen species (ROS). They are the part of important mechanism which is responsible for the process of aging and the development of many diseases. The most important effects result from DNA damage, due to the mutations formation, which can lead to the development of tumors. However, a well-functioning repair systems (i.a. homologous recombination) remove the damage and prevent harmful changes in the cells. Lipid peroxidation products also cause oxidative modification of nucleic acids (and proteins). Proteins and fats also have repair systems, but much simpler than those responsible for the repair of nucleic acids. Unfortunately, with increasing age, they are more weakened, which contributes to increase numbers of cell damage, and consequently development of diseases specific to old age: cancer, neurodegenerative diseases or atherosclerosis.

  10. Formal definition of coherency and computation of minimal cut sequences for binary dynamic and repairable systems

    International Nuclear Information System (INIS)

    Chaux, Pierre-Yves

    2013-01-01

    Preventive risk assessment of a complex system rely on a dynamic models which describe the link between the system failure and the scenarios of failure and repair events from its components. The qualitative analyses of a binary dynamic and repairable system is aiming at computing and analyse the scenarios that lead to the system failure. Since such systems describe a large set of those, only the most representative ones, called Minimal Cut Sequences (MCS), are of interest for the safety engineer. The lack of a formal definition for the MCS has generated multiple definitions either specific to a given model (and thus not generic) or informal. This work proposes i) a formal framework and definition for the MCS while staying independent of the reliability model used, ii) the methodology to compute them using property extracted from their formal definition, iii) an extension of the formal framework for multi-states components in order to perform the qualitative analyses of Boolean logic Driven Markov Processes (BDMP) models. Under the hypothesis that the scenarios implicitly described by any reliability model can always be represented by a finite automaton, this work is defining the coherency for dynamic and repairable systems as the way to give a minimal representation of all scenarios that are leading to the system failure. (author)

  11. RNA damage in biological conflicts and the diversity of responding RNA repair systems

    Science.gov (United States)

    Burroughs, A. Maxwell; Aravind, L.

    2016-01-01

    RNA is targeted in biological conflicts by enzymatic toxins or effectors. A vast diversity of systems which repair or ‘heal’ this damage has only recently become apparent. Here, we summarize the known effectors, their modes of action, and RNA targets before surveying the diverse systems which counter this damage from a comparative genomics viewpoint. RNA-repair systems show a modular organization with extensive shuffling and displacement of the constituent domains; however, a general ‘syntax’ is strongly maintained whereby systems typically contain: a RNA ligase (either ATP-grasp or RtcB superfamilies), nucleotidyltransferases, enzymes modifying RNA-termini for ligation (phosphatases and kinases) or protection (methylases), and scaffold or cofactor proteins. We highlight poorly-understood or previously-uncharacterized repair systems and components, e.g. potential scaffolding cofactors (Rot/TROVE and SPFH/Band-7 modules) with their respective cognate non-coding RNAs (YRNAs and a novel tRNA-like molecule) and a novel nucleotidyltransferase associating with diverse ligases. These systems have been extensively disseminated by lateral transfer between distant prokaryotic and microbial eukaryotic lineages consistent with intense inter-organismal conflict. Components have also often been ‘institutionalized’ for non-conflict roles, e.g. in RNA-splicing and in RNAi systems (e.g. in kinetoplastids) which combine a distinct family of RNA-acting prim-pol domains with DICER-like proteins. PMID:27536007

  12. Systems and methods for treating material

    Science.gov (United States)

    Scheele, Randall D; McNamara, Bruce K

    2014-10-21

    Systems for treating material are provided that can include a vessel defining a volume, at least one conduit coupled to the vessel and in fluid communication with the vessel, material within the vessel, and NF.sub.3 material within the conduit. Methods for fluorinating material are provided that can include exposing the material to NF.sub.3 to fluorinate at least a portion of the material. Methods for separating components of material are also provided that can include exposing the material to NF.sub.3 to at least partially fluorinate a portion of the material, and separating at least one fluorinated component of the fluorinated portion from the material. The materials exposed to the NF.sub.3 material can include but are not limited to one or more of U, Ru, Rh, Mo, Tc, Np, Pu, Sb, Ag, Am, Sn, Zr, Cs, Th, and/or Rb.

  13. In-situ change and repairing method of armour tile made of carbon fiber composite material in divertor

    International Nuclear Information System (INIS)

    Ishiyama, Shintaro.

    1994-01-01

    A joint portion of a damaged armour tile of a carbon fiber composite material and a divertor substrate is locally heated spontaneously to re-melt the soldering. Then, the damaged tile is removed and the portion where the tile is removed is heated again to melt the soldering, then a tile for exchange is joined. Alternatively, a thermosetting type adhesive is coated on the surface of the damaged armour tile made of carbon fiber composite material on the divertor, and a tile for repairing is adhered thereon then the joint surface is locally heated to cure the adhesive. For local heating, for example, high frequency heating or dielectric heating is used. It is preferably conducted by remote handling by using robot arms under vacuum in an vacuum vessel of the thermonuclear device. The operations of the heating and pressurization for the joint surface are preferably repeated for several times. (N.H.)

  14. Generalized renewal process for repairable systems based on finite Weibull mixture

    International Nuclear Information System (INIS)

    Veber, B.; Nagode, M.; Fajdiga, M.

    2008-01-01

    Repairable systems can be brought to one of possible states following a repair. These states are: 'as good as new', 'as bad as old' and 'better than old but worse than new'. The probabilistic models traditionally used to estimate the expected number of failures account for the first two states, but they do not properly apply to the last one, which is more realistic in practice. In this paper, a probabilistic model that is applicable to all of the three after-repair states, called generalized renewal process (GRP), is applied. Simplistically, GRP addresses the repair assumption by introducing the concept of virtual age into the stochastic point processes to enable them to represent the full spectrum of repair assumptions. The shape of measured or design life distributions of systems can vary considerably, and therefore frequently cannot be approximated by simple distribution functions. The scope of the paper is to prove that a finite Weibull mixture, with positive component weights only, can be used as underlying distribution of the time to first failure (TTFF) of the GRP model, on condition that the unknown parameters can be estimated. To support the main idea, three examples are presented. In order to estimate the unknown parameters of the GRP model with m-fold Weibull mixture, the EM algorithm is applied. The GRP model with m mixture components distributions is compared to the standard GRP model based on two-parameter Weibull distribution by calculating the expected number of failures. It can be concluded that the suggested GRP model with Weibull mixture with an arbitrary but finite number of components is suitable for predicting failures based on the past performance of the system

  15. A decision dependent stochastic process model for repairable systems with applications

    Directory of Open Access Journals (Sweden)

    Paul F. Zantek

    2015-12-01

    This paper mathematically formalizes the notion of how management actions impact the functioning of a repairable system over time by developing a new stochastic process model for such systems. The proposed model is illustrated using both simulated and real data. The proposed model compares favorably to other models for well-known data on Boeing airplanes. The model is further illustrated and compared to other models on failure time and maintenance data stemming from the South Texas Project nuclear power plant.

  16. Multi-echelon Repair Inventory Systems: Select Issues in Modular Electronic Equipment

    OpenAIRE

    Amik Garg; S. G. Deshmukh

    2010-01-01

    Flow of modules/printed circuit boards (PCBs) in a multi-echelon repair inventory system pertaining to modular electronic equipment for large maintenance organisations having large inventory in range and depth, like defence has been critically examined using a case study. Desirable features of the proposed system are identified and a general framework suggested for examining its feasibility and implementation in an organisation. An analytical model with an objective to reduce number of echelo...

  17. Automated accounting systems for nuclear materials

    International Nuclear Information System (INIS)

    Erkkila, B.

    1994-01-01

    History of the development of nuclear materials accounting systems in USA and their purposes are considered. Many present accounting systems are based on mainframe computers with multiple terminal access. Problems of future improvement accounting systems are discussed

  18. Non-periodic preventive maintenance with reliability thresholds for complex repairable systems

    International Nuclear Information System (INIS)

    Lin, Zu-Liang; Huang, Yeu-Shiang; Fang, Chih-Chiang

    2015-01-01

    In general, a non-periodic condition-based PM policy with different condition variables is often more effective than a periodic age-based policy for deteriorating complex repairable systems. In this study, system reliability is estimated and used as the condition variable, and three reliability-based PM models are then developed with consideration of different scenarios which can assist in evaluating the maintenance cost for each scenario. The proposed approach provides the optimal reliability thresholds and PM schedules in advance by which the system availability and quality can be ensured and the organizational resources can be well prepared and managed. The results of the sensitivity anlysis indicate that PM activities performed at a high reliability threshold can not only significantly improve the system availability but also efficiently extend the system lifetime, although such a PM strategy is more costly than that for a low reliabiltiy threshold. The optimal reliability threshold increases along with the number of PM activities to prevent future breakdowns caused by severe deterioration, and thus substantially reduces repair costs. - Highlights: • The PM problems for repairable deteriorating systems are formulated. • The structural properties of the proposed PM models are investigated. • The corresponding algorithms to find the optimal PM strategies are provided. • Imperfect PM activities are allowed to reduce the occurences of breakdowns. • Provide managers with insights about the critical factors in the planning stage

  19. Optimisation of integrated energy and materials systems

    International Nuclear Information System (INIS)

    Gielen, D.J.; Okken, P.A.

    1994-06-01

    To define cost-effective long term CO2 reduction strategies an integrated energy and materials system model for the Netherlands for the period 2000-2040 is developed. The model is based upon the energy system model MARKAL, which configures an optimal mix of technologies to satisfy the specified energy and product/materials service demands. This study concentrates on CO 2 emission reduction in the materials system. For this purpose, the energy system model is enlarged with a materials system model including all steps 'from cradle to grave'. The materials system model includes 29 materials, 20 product groups and 30 waste materials. The system is divided into seven types of technologies; 250 technologies are modeled. The results show that the integrated optimisation of the energy system and the materials system can significantly reduce the emission reduction costs, especially at higher reduction percentages. The reduction is achieved through shifts in materials production and waste handling and through materials substitution in products. Shifts in materials production and waste management seem cost-effective, while the cost-effectiveness of shifts in product composition is sensitive due to the cost structure of products. For the building sector, transportation applications and packaging, CO 2 policies show a significant impact on prices, and shifts in product composition could occur. For other products, the reduction through materials substitution seems less promising. The impact on materials consumption seems most significant for cement (reduced), timber and aluminium (both increased). For steel and plastics, the net effect is balanced, but shifts between applications do occur. The MARKAL-approach is feasible to study integrated energy and materials systems. The progress compared to other environmental system analysis instruments is much more insight in the interaction of technologies on a national scale and in time

  20. Reliability Analysis of 6-Component Star Markov Repairable System with Spatial Dependence

    Directory of Open Access Journals (Sweden)

    Liying Wang

    2017-01-01

    Full Text Available Star repairable systems with spatial dependence consist of a center component and several peripheral components. The peripheral components are arranged around the center component, and the performance of each component depends on its spatial “neighbors.” Vector-Markov process is adapted to describe the performance of the system. The state space and transition rate matrix corresponding to the 6-component star Markov repairable system with spatial dependence are presented via probability analysis method. Several reliability indices, such as the availability, the probabilities of visiting the safety, the degradation, the alert, and the failed state sets, are obtained by Laplace transform method and a numerical example is provided to illustrate the results.

  1. Development of laser cladding system to repair wall thinning of 1-inch heat exchanger tube

    International Nuclear Information System (INIS)

    Terada, Takaya

    2013-01-01

    We developed a laser cladding system to repair the inner wall wastage of heat exchanger tubes. Our system, which is designed to repair thinning tube walls within 100 mm from the edge of a heat exchanger tube, consists of a fiber laser, a composite-type optical fiberscope, a coupling device, a laser processing head, and a wire-feeding device. All of these components were reconfigured from the technologies of FBR maintenance. The laser processing head, which has a 15-mm outer diameter, was designed to be inserted into a 1-inch heat exchanger tube. We mounted a heatproof broadband mirror for laser cladding and fiberscope observation with visible light inside the laser processing head. The wire-feeding device continuously supplied 0.4-mm wire to the laser irradiation spot with variable feeding speeds from 0.5 to 20 mm/s. We are planning to apply our proposed system to the maintenance of aging industrial plants. (author)

  2. A shock and wear system under environmental conditions subject to internal failures, repair, and replacement

    International Nuclear Information System (INIS)

    Montoro-Cazorla, Delia; Pérez-Ocón, Rafael

    2012-01-01

    A system in a random environment is considered. The influence of the external conditions is governed by a Markovian arrival process. The internal structure of failure and repair are governed by phase-type distributions. The maintenance is performed by policy N. Under these assumptions, the Markov process governing the system is constructed, and it is studied in transient and stationary regime, calculating the availability and the rate of occurrence of failures. The renewal process due to the replacements of the system is studied, and expressions for the number of replacements and for the number of repairs between replacements are calculated. This paper extends other previously published since it incorporates a shock arrival process with dependence among the interarrival times and the renewal process associated to the replacements. A numerical application illustrates the calculations.

  3. Armor systems including coated core materials

    Science.gov (United States)

    Chu, Henry S [Idaho Falls, ID; Lillo, Thomas M [Idaho Falls, ID; McHugh, Kevin M [Idaho Falls, ID

    2012-07-31

    An armor system and method involves providing a core material and a stream of atomized coating material that comprises a liquid fraction and a solid fraction. An initial layer is deposited on the core material by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is less than the liquid fraction of the stream of atomized coating material on a weight basis. An outer layer is then deposited on the initial layer by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is greater than the liquid fraction of the stream of atomized coating material on a weight basis.

  4. Rare event simulation for highly dependable systems with fast repairs

    NARCIS (Netherlands)

    Reijsbergen, D.P.; de Boer, Pieter-Tjerk; Scheinhardt, Willem R.W.; Haverkort, Boudewijn R.H.M.

    2010-01-01

    Stochastic model checking has been used recently to assess, among others, dependability measures for a variety of systems. However, the employed numerical methods, as, e.g., supported by model checking tools such as PRISM and MRMC, suffer from the state-space explosion problem. The main alternative

  5. Rare event simulation for highly dependable systems with fast repairs

    NARCIS (Netherlands)

    Reijsbergen, D.P.; de Boer, Pieter-Tjerk; Scheinhardt, Willem R.W.; Haverkort, Boudewijn R.H.M.

    Probabilistic model checking has been used recently to assess, among others, dependability measures for a variety of systems. However, the numerical methods employed, such as those supported by model checking tools such as PRISM and MRMC, suffer from the state-space explosion problem. The main

  6. Automated TIG welding system with visual sensor for repairing nuclear plants

    International Nuclear Information System (INIS)

    Inoue, Katsunori; Watanabe, Hiroshi; Kondoh, Yoshihide.

    1986-01-01

    An automated TIG welding system has been developed. This system is to be used for repairing nuclear plants, whose work environment is highly radioactive, so should have the automatic self control function and the remote controllable function. For this purpose, the visual sensor, a TV camera and an image processor, is installed and the image processing technique is applied to the all-position TIG welding system. In this system, all controls are made with microprocessors and every necessary information is displayed on the screen of the remote control unit. The excellent performance was obtained as the application of this system to the practical field. (author)

  7. PAMTRAK: A personnel and material tracking system

    International Nuclear Information System (INIS)

    Anspach, D.A.; Anspach, J.P.; Crain, B. Jr.

    1996-01-01

    There is a need for an automated system for protecting and monitoring sensitive or classified parts and material. Sandia has developed a real-time personnel and material tracking system (PAMTRAK) that has been installed at selected DOE facilities. It safeguards sensitive parts and material by tracking tags worn by personnel and by monitoring sensors attached to the parts or material. It includes remote control and alarm display capabilities and a complementary program in Keyhole to display measured material attributes remotely. This paper describes the design goals, the system components, current installations, and the benefits a site can expect when using PAMTRAK

  8. Rapid road repair vehicle

    Science.gov (United States)

    Mara, Leo M.

    1998-01-01

    Disclosed is a rapid road repair vehicle capable of moving over a surface to be repaired at near normal posted traffic speeds to scan for and find an the high rate of speed, imperfections in the pavement surface, prepare the surface imperfection for repair by air pressure and vacuum cleaning, applying a correct amount of the correct patching material to effect the repair, smooth the resulting repaired surface, and catalog the location and quality of the repairs for maintenance records of the road surface. The rapid road repair vehicle can repair surface imperfections at lower cost, improved quality, at a higher rate of speed than was was heretofor possible, with significantly reduced exposure to safety and health hazards associated with this kind of road repair activities in the past.

  9. Improved cladding nano-structured materials with self-repairing capabilities

    International Nuclear Information System (INIS)

    Popa-Simil, L.

    2012-01-01

    When designing nuclear reactors or the materials that go into them, one of the key challenges is finding materials that can withstand an outrageously extreme environment. In addition to constant bombardment by radiation, reactor materials may be subjected to extremes in temperature, physical stress, and corrosive conditions. A limitation in fuel burnup is and usage of the nuclear fuel material is related to the structural material radiation damage, that makes the fuel be removed with low-burnup and immobilized in the waste storage pools. The advanced burnup brings cladding material embitterment due to radiation damage effects corroborated with corrosion effects makes the fuel pellet life shorter. The novel nano-clustered structured sintered material may mitigate simultaneously the radiation damage and corrosion effects driving to more robust structural materials that may make the nuclear reactor safer and more reliable. The development of nano-clustered sinter alloys provides new avenues for further examination of the role of grain boundaries and engineered material interfaces in self-healing of radiation-induced defects driving to the design of highly radiation-tolerant materials for the next generation of nuclear energy applications. (authors)

  10. Computerized reactor pressure vessel materials information system

    International Nuclear Information System (INIS)

    Strosnider, J.; Monserrate, C.; Kenworthy, L.D.; Tether, C.D.

    1980-10-01

    A computerized information system for storage and retrieval of reactor pressure vessel materials data was established, as part of Task Action Plan A-11, Reactor Vessel Materials Toughness. Data stored in the system are necessary for evaluating the resistance of reactor pressure vessels to flaw-induced fracture. This report includes (1) a description of the information system; (2) guidance on accessing the system; and (3) a user's manual for the system

  11. Uncertain multiobjective redundancy allocation problem of repairable systems based on artificial bee colony algorithm

    Institute of Scientific and Technical Information of China (English)

    Guo Jiansheng; Wang Zutong; Zheng Mingfa; Wang Ying

    2014-01-01

    Based on the uncertainty theory, this paper is devoted to the redundancy allocation problem in repairable parallel-series systems with uncertain factors, where the failure rate, repair rate and other relative coefficients involved are considered as uncertain variables. The availability of the system and the corresponding designing cost are considered as two optimization objectives. A crisp multiobjective optimization formulation is presented on the basis of uncertainty theory to solve this resultant problem. For solving this problem efficiently, a new multiobjective artificial bee colony algorithm is proposed to search the Pareto efficient set, which introduces rank value and crowding distance in the greedy selection strategy, applies fast non-dominated sort procedure in the exploitation search and inserts tournament selection in the onlooker bee phase. It shows that the proposed algorithm outperforms NSGA-II greatly and can solve multiobjective redundancy allocation problem efficiently. Finally, a numerical example is provided to illustrate this approach.

  12. Radial Internal Material Handling System (RIMS) for Circular Habitat Volumes

    Science.gov (United States)

    Howe, Alan S.; Haselschwardt, Sally; Bogatko, Alex; Humphrey, Brian; Patel, Amit

    2013-01-01

    On planetary surfaces, pressurized human habitable volumes will require a means to carry equipment around within the volume of the habitat, regardless of the partial gravity (Earth, Moon, Mars, etc.). On the NASA Habitat Demonstration Unit (HDU), a vertical cylindrical volume, it was determined that a variety of heavy items would need to be carried back and forth from deployed locations to the General Maintenance Work Station (GMWS) when in need of repair, and other equipment may need to be carried inside for repairs, such as rover parts and other external equipment. The vertical cylindrical volume of the HDU lent itself to a circular overhead track and hoist system that allows lifting of heavy objects from anywhere in the habitat to any other point in the habitat interior. In addition, the system is able to hand-off lifted items to other material handling systems through the side hatches, such as through an airlock. The overhead system consists of two concentric circle tracks that have a movable beam between them. The beam has a hoist carriage that can move back and forth on the beam. Therefore, the entire system acts like a bridge crane curved around to meet itself in a circle. The novelty of the system is in its configuration, and how it interfaces with the volume of the HDU habitat. Similar to how a bridge crane allows coverage for an entire rectangular volume, the RIMS system covers a circular volume. The RIMS system is the first generation of what may be applied to future planetary surface vertical cylinder habitats on the Moon or on Mars.

  13. A systems approach to inventory management of repairables in the Navy

    OpenAIRE

    Apple, Chris Leon

    1985-01-01

    Approved for public release; distribution is unlimited This thesis develops an inventory model for repairable items which integrates the shipboard protection level into the wholesale stock level computations. It uses mean supply response time (MSRT) as its measure of effectiveness and provides methods for computing either the required wholesale stock level given a MSRT goal or for minimizing the system MSRT subject to budgetary constraints. Examples are provided which demons...

  14. Novel Combinatory Approaches to Repair Visual System after Optic Nerve Damage

    Science.gov (United States)

    2014-09-01

    Novel Combinatory Approaches to Repair Visual System After Optic Nerve Damage 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...biological functions such as metabolism, growth, cell cycle, and survival ( Cardone et al., 1998; Diehl, Cheng, Roussel, & Sherr, 1998; Hers, Vincent...of injured adult sensory neurons. The Journal of Neuroscience, 21, 7161–7170. Cardone , M. H., Roy, N., Stennicke, H. R., Salvesen, G. S., Franke, T. F

  15. New materials options for nuclear systems

    International Nuclear Information System (INIS)

    Jones, R.H.; Garner, F.A.; Bruemmer, S.M.; Gelles, D.S.

    1989-01-01

    Development of new materials for nuclear reactor systems is continuing to produce options for improved reactor designs. Materials with reduced environment-induced crack growth is a key materials issue for the light water reactor (LWR) industry while the development of low activation ferritic, austenitic and vanadium alloys has been an active area for materials development for fusion reactor structural applications. Development of advanced materials such as metal matrix and ceramic matrix composites for reactor systems have received a limited amount of attention. (author)

  16. An application of modulated poisson processes to the reliability analysis of repairable systems

    Energy Technology Data Exchange (ETDEWEB)

    Saldanha, Pedro L.C. [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil). Coordenacao de Reatores]. E-mail: saldanha@cnen.gov.br; Melo, P.F. Frutuoso e [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear]. E-mail: frutuoso@con.ufrj.br; Noriega, Hector C. [Universidad Austral de Chile (UACh), Valdivia (Chile). Faculdad de Ciencias de la Ingeniaria]. E-mail: hnoriega@uach.cl

    2005-07-01

    This paper discusses the application of the modulated power law process (MPLP) model to the rate of occurrence of failures of active repairable systems in reliability engineering. Traditionally, two ways of modeling repairable systems, in what concerns maintenance policies, are: a pessimistic approach (non-homogeneous process - NHPP), and a very optimistic approach (renewal processes - RP). It is important to build a generalized model that might consider characteristics and properties both of the NHPP and of the RP models as particular cases. In practice, by considering the pattern of times between failures, the MPLP appears to be more realistic to represent the occurrence of failures of repairable systems in order to define whether they can be modeled by a homogeneous or a non-homogeneous process. The study has shown that the model can be used to make decisions concerning the evaluation of the qualified life of plant equipment. By controlling and monitoring two of the three parameters of the MPLP model during the equipment operation, it is possible to check whether and how the equipment is following the basis of its qualification process, and so identify how the effects of time, degradation and operation modes are influencing the equipment performance. The discussion is illustrated by an application to the service water pumps of a typical PWR plant. (author)

  17. Aircraft Propeller Hub Repair

    Energy Technology Data Exchange (ETDEWEB)

    Muth, Thomas R [ORNL; Peter, William H [ORNL

    2015-02-13

    The team performed a literature review, conducted residual stress measurements, performed failure analysis, and demonstrated a solid state additive manufacturing repair technique on samples removed from a scrapped propeller hub. The team evaluated multiple options for hub repair that included existing metal buildup technologies that the Federal Aviation Administration (FAA) has already embraced, such as cold spray, high velocity oxy-fuel deposition (HVOF), and plasma spray. In addition the team helped Piedmont Propulsion Systems, LLC (PPS) evaluate three potential solutions that could be deployed at different stages in the life cycle of aluminum alloy hubs, in addition to the conventional spray coating method for repair. For new hubs, a machining practice to prevent fretting with the steel drive shaft was recommended. For hubs that were refurbished with some material remaining above the minimal material condition (MMC), a silver interface applied by an electromagnetic pulse additive manufacturing method was recommended. For hubs that were at or below the MMC, a solid state additive manufacturing technique using ultrasonic welding (UW) of thin layers of 7075 aluminum to the hub interface was recommended. A cladding demonstration using the UW technique achieved mechanical bonding of the layers showing promise as a viable repair method.

  18. Structural materials for fusion reactor blanket systems

    International Nuclear Information System (INIS)

    Bloom, E.E.; Smith, D.L.

    1984-01-01

    Consideration of the required functions of the blanket and the general chemical, mechanical, and physical properties of candidate tritium breeding materials, coolants, structural materials, etc., leads to acceptable or compatible combinations of materials. The presently favored candidate structural materials are the austenitic stainless steels, martensitic steels, and vanadium alloys. The characteristics of these alloy systems which limit their application and potential performance as well as approaches to alloy development aimed at improving performance (temperature capability and lifetime) will be described. Progress towards understanding and improving the performance of structural materials has been substantial. It is possible to develop materials with acceptable properties for fusion applications

  19. Climate control systems using pozzolan materials

    KAUST Repository

    Almadhoun, Mahmoud Nassar Mahmoud

    2016-01-01

    A system and method for conditioning air is provided that optimizes the use of sustainable and locally sourced materials with agrarian, residential, and industrial applications. The system can be formed with a porous siliceous, or siliceous

  20. Development of nuclear material accountancy control system

    International Nuclear Information System (INIS)

    Hirosawa, Naonori; Kashima, Sadamitsu; Akiba, Mitsunori

    1992-01-01

    PNC is developing a wide area of nuclear fuel cycle. Therefore, much nuclear material with a various form exists at each facility in the Works, and the controls of the inventory changes and the physical inventories of nuclear material are important. Nuclear material accountancy is a basic measure in safeguards system based on Non-Proliferation Treaty (NPT). In the light of such importance of material accountancy, the data base of nuclear material control and the material accountancy report system for all facilities has been developed by using the computer. By this system, accountancy report to STA is being presented certainly and timely. Property management and rapid corresponding to various inquiries can be carried out by the data base system which has free item searching procedure. (author)

  1. CMB-8 material balance system

    International Nuclear Information System (INIS)

    Langner, D.; Canada, T.; Ensslin, N.; Atwell, T.; Baxman, H.; Cowder, L.; Speir, L.; Lyssel, T.V.; Sampson, T.

    1980-08-01

    We describe the automated nondestructive assay (NDA) system installed at the Los Alamos Scientific Laboratory (LASL) Group CMB-8 uranium recovery facility. A random driver (RD) is used to measure the 235 U content of various solids while a uranium solution assay system (USAS) measures the 235 U or total uranium content of solutions over a concentration range of a few ppM to 400 g/l. Both instruments are interfaced to and controlled by a single minicomputer. The measurement principles, mechanical specifications, system software description, and operational instructions are described

  2. A New Approach for Analyzing the Reliability of the Repair Facility in a Series System with Vacations

    Directory of Open Access Journals (Sweden)

    Renbin Liu

    2012-01-01

    Full Text Available Based on the renewal process theory we develop a decomposition method to analyze the reliability of the repair facility in an n-unit series system with vacations. Using this approach, we study the unavailability and the mean replacement number during (0,t] of the repair facility. The method proposed in this work is novel and concise, which can make us see clearly the structures of the facility indices of a series system with an unreliable repair facility, two convolution relations. Special cases and numerical examples are given to show the validity of our method.

  3. Operational advanced materials control and accountability system

    International Nuclear Information System (INIS)

    Malanify, J.J.; Bearse, R.C.; Christensen, E.L.

    1980-01-01

    An accountancy system based on the Dynamic Materials Accountability (DYMAC) System has been in operation at the Plutonium Processing Facility at the Los Alamos Scientific Laboratory (LASL) since January 1978. This system, now designated the Plutonium Facility/Los Alamos Safeguards System (PF/LASS), has enhanced nuclear material accountability and process control at the LASL facility. The nondestructive assay instruments and the central computer system are operating accurately and reliably. As anticipated, several uses of the system have developed in addition to safeguards, notably scrap control and quality control. The successes of this experiment strongly suggest that implementation of DYMAC-based systems should be attempted at other facilities. 20 refs

  4. Interactions of radiation repair systems in escherichia colt with antineoplastic anthracyclines

    International Nuclear Information System (INIS)

    Kacinski, B.M.; Rupp, W.D.

    1984-01-01

    The authors have studied the interactions of several anthracylines with the UVR DN*a repair system of E. coli. The authors found that doxorubicin is quite toxic for uvr- but not for uvr+strains. They also found that exposure of cells carrying a multicopy plasmid to this agent yielded plasmid DNA molecules with lesions which were recognized and cleaved by purified E. coli UVRABC DNA repair endonuclease. A derivative of doxorubicin was not measurably toxic for either uvr+ or uvr- strains but nevertheless produced lesions which were substrates for the UVRABC endonuclease. The authors propose that anthracycline toxicity in uvr- E. coli may correlate with clinical toxicity while anthracylcine antineopolastic activity may correlate with their ability to produce UVRABC endonuclease-sensitive DNA damage

  5. Bioactive Molecule-loaded Drug Delivery Systems to Optimize Bone Tissue Repair.

    Science.gov (United States)

    Oshiro, Joao Augusto; Sato, Mariana Rillo; Scardueli, Cassio Rocha; Lopes de Oliveira, Guilherme Jose Pimentel; Abucafy, Marina Paiva; Chorilli, Marlus

    2017-01-01

    Bioactive molecules such as peptides and proteins can optimize the repair of bone tissue; however, the results are often unpredictable when administered alone, owing to their short biological half-life and instability. Thus, the development of bioactive molecule-loaded drug delivery systems (DDS) to repair bone tissue has been the subject of intense research. DDS can optimize the repair of bone tissue owing to their physicochemical properties, which improve cellular interactions and enable the incorporation and prolonged release of bioactive molecules. These characteristics are fundamental to favor bone tissue homeostasis, since the biological activity of these factors depends on how accessible they are to the cell. Considering the importance of these DDS, this review aims to present relevant information on DDS when loaded with osteogenic growth peptide and bone morphogenetic protein. These are bioactive molecules that are capable of modulating the differentiation and proliferation of mesenchymal cells in bone tissue cells. Moreover, we will present different approaches using these peptide and protein-loaded DDS, such as synthetic membranes and scaffolds for bone regeneration, synthetic grafts, bone cements, liposomes, and micelles, which aim at improving the therapeutic effectiveness, and we will compare their advantages with commercial systems. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  6. THE WORK SIMULATION OF FLOW RATE FOR CARRIAGES' REPAIR AS A MULTIPHASE, MULTIPLEX AND MULTIDISCIPLINARY SYSTEM OF MASS SERVICE

    Directory of Open Access Journals (Sweden)

    V. V. Myamlin

    2011-04-01

    Full Text Available The algorithm of computer simulation of the flexible flow for repair of cars as a multiphase polychannel manyobject queuing system is presented. The basic operators of the model are given and their work is described.

  7. Surgical modification for preventing a gothic arch after aortic arch repair without the use of foreign material.

    Science.gov (United States)

    Seo, Dong-Man; Park, Jiyoung; Goo, Hyun Woo; Kim, Young Hwue; Ko, Jae-Kon; Jhang, Won Kyoung

    2015-04-01

    Systemic hypertension is the main late complication after arch reconstruction in patients with arch obstruction. Gothic arch geometry is suspected to be one of its possible causes. Accordingly, we evaluated here if a modified arch repair technique using an autologous pulmonary patch is effective in preventing gothic arch development. Fifty infants who underwent arch repair with either a modified (n = 17) or conventional (n = 33) technique between January 2006 and August 2012 by a single surgeon were retrospectively reviewed. Arch geometry was compared using three categories (gothic, crenel or roman), classified by the height/width (H/W) ratio and the arch angle measured in computed tomography. No gothic arch geometry was observed in the modified group, whereas it was observed in 9 cases in the conventional group (P = 0.005). Moreover, reintervention for arch restenosis was performed only in the conventional group (n = 4; P = 0.29). No associated complications were observed, although the selective cerebral perfusion time was longer in the modified group than in the conventional group (28.5 ± 6.2 vs 17.1 ± 9.9 min; P gothic arch geometry, but also as equally safe in terms of early clinical outcomes as conventional arch reconstruction techniques. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  8. Modernizing computerized nuclear material accounting systems

    International Nuclear Information System (INIS)

    Erkkila, B.H.; Claborn, J.

    1995-01-01

    DOE Orders and draft orders for nuclear material control and accountability address a complete material control and accountability (MC and A) program for all DOE contractors processing, using, or storing nuclear materials. A critical element of an MC and A program is the accounting system used to track and record all inventories of nuclear material and movements of materials in those inventories. Most DOE facilities use computerized accounting systems to facilitate the task of accounting for all their inventory of nuclear materials. Many facilities still use a mixture of a manual paper system with a computerized system. Also, facilities may use multiple systems to support information needed for MC and A. For real-time accounting it is desirable to implement a single integrated data base management system for a variety of users. In addition to accountability needs, waste management, material management, and production operations must be supported. Information in these systems can also support criticality safety and other safety issues. Modern networked microcomputers provide extensive processing and reporting capabilities that single mainframe computer systems struggle with. This paper describes an approach being developed at Los Alamos to address these problems

  9. Role of the immune system in cardiac tissue damage and repair following myocardial infarction.

    Science.gov (United States)

    Saparov, Arman; Ogay, Vyacheslav; Nurgozhin, Talgat; Chen, William C W; Mansurov, Nurlan; Issabekova, Assel; Zhakupova, Jamilya

    2017-09-01

    The immune system plays a crucial role in the initiation, development, and resolution of inflammation following myocardial infarction (MI). The lack of oxygen and nutrients causes the death of cardiomyocytes and leads to the exposure of danger-associated molecular patterns that are recognized by the immune system to initiate inflammation. At the initial stage of post-MI inflammation, the immune system further damages cardiac tissue to clear cell debris. The excessive production of reactive oxygen species (ROS) by immune cells and the inability of the anti-oxidant system to neutralize ROS cause oxidative stress that further aggravates inflammation. On the other hand, the cells of both innate and adaptive immune system and their secreted factors are critically instrumental in the very dynamic and complex processes of regulating inflammation and mediating cardiac repair. It is important to decipher the balance between detrimental and beneficial effects of the immune system in MI. This enables us to identify better therapeutic targets for reducing the infarct size, sustaining the cardiac function, and minimizing the likelihood of heart failure. This review discusses the role of both innate and adaptive immune systems in cardiac tissue damage and repair in experimental models of MI.

  10. Elastocaloric cooling materials and systems

    Science.gov (United States)

    Takeuchi, Ichiro

    2015-03-01

    We are actively pursuing applications of thermoelastic (elastocaloric) cooling using shape memory alloys. Latent heat associated with martensitic transformation of shape memory alloys can be used to run cooling cycles with stress-inducing mechanical drives. The coefficient of performance of thermoelastic cooling materials can be as high as 11 with the directly measured DT of around 17 °C. Depending on the stress application mode, the number of cycles to fatigue can be as large as of the order of 105. Efforts to design and develop thermoelastic alloys with long fatigue life will be discussed. The current project at the University of Maryland is focused on development of building air-conditioners, and at Maryland Energy and Sensor Technologies, smaller scale commercial applications are being pursued. This work is carried out in collaboration with Jun Cui, Yiming Wu, Suxin Qian, Yunho Hwang, Jan Muehlbauer, and Reinhard Radermacher, and it is funded by the ARPA-E BEETIT program and the State of Maryland.

  11. Meniscal repair devices.

    Science.gov (United States)

    Barber, F A; Herbert, M A

    2000-09-01

    Meniscal repair devices not requiring accessory incisions are attractive. Many factors contribute to their clinical effectiveness including their biomechanical characteristics. This study compared several new meniscal repair devices with standard meniscal suture techniques. Using a porcine model, axis-of-insertion loads were applied to various meniscal sutures and repair devices. A single device or stitch was placed in a created meniscal tear and a load applied. Both loads and modes of failure were recorded. The load-to-failure data show stratification into 4 distinct statistical groups. Group A, 113 N for a double vertical stitch; group B, 80 N for a single vertical stitch; group C, 57 N for the BioStinger, 56 N for a horizontal mattress stitch, and 50 N for the T-Fix stitch; and group D, 33 N for the Meniscus Arrow (inserted by hand or gun), 32 N for the Clearfix screw, 31 N for the SDsorb staple, 30 N for the Mitek meniscal repair system, and 27 N for the Biomet staple. The failure mechanism varied. Sutures broke away from the knot. The Meniscus Arrow and BioStinger pulled through the inner rim with the crossbar intact. The Clearfix screw failed by multiple mechanisms, whereas 1 leg of the SDsorb staple always pulled out of the outer rim. The Mitek device usually failed by pullout from the inner rim. The Biomet staple always broke at the crosshead or just below it. Although the surgeon should be aware of the material properties of the repair technique chosen for a meniscal repair, this information is only an indication of device performance and may not correlate with clinical healing results.

  12. Calcium Carbonate Formation in Water Distribution Systems and Autogenous Repair of Leaks by Inert Particle Clogging

    OpenAIRE

    Richards, Colin Scott

    2016-01-01

    The formation of calcium carbonate (CaCO3) (i.e. scale) in potable water systems has long been a concern in water treatment and distribution. A literature review reveals that CaCO3 scaling issues are re-emerging due to climate change, temperature increases in hot water systems and lower use of scaling and corrosion inhibitors. Moreover, we have gathered insights that suggest CaCO3 coatings can be beneficial and stop pipeline leaks via self-repair or clogging. Ironically, the actions we are ta...

  13. An Inducible, Isogenic Cancer Cell Line System for Targeting the State of Mismatch Repair Deficiency

    Science.gov (United States)

    Bailis, Julie M.; Gordon, Marcia L.; Gurgel, Jesse L.; Komor, Alexis C.; Barton, Jacqueline K.; Kirsch, Ilan R.

    2013-01-01

    The DNA mismatch repair system (MMR) maintains genome stability through recognition and repair of single-base mismatches and small insertion-deletion loops. Inactivation of the MMR pathway causes microsatellite instability and the accumulation of genomic mutations that can cause or contribute to cancer. In fact, 10-20% of certain solid and hematologic cancers are MMR-deficient. MMR-deficient cancers do not respond to some standard of care chemotherapeutics because of presumed increased tolerance of DNA damage, highlighting the need for novel therapeutic drugs. Toward this goal, we generated isogenic cancer cell lines for direct comparison of MMR-proficient and MMR-deficient cells. We engineered NCI-H23 lung adenocarcinoma cells to contain a doxycycline-inducible shRNA designed to suppress the expression of the mismatch repair gene MLH1, and compared single cell subclones that were uninduced (MLH1-proficient) versus induced for the MLH1 shRNA (MLH1-deficient). Here we present the characterization of these MMR-inducible cell lines and validate a novel class of rhodium metalloinsertor compounds that differentially inhibit the proliferation of MMR-deficient cancer cells. PMID:24205301

  14. DNA Mismatch Repair System: Repercussions in Cellular Homeostasis and Relationship with Aging

    Directory of Open Access Journals (Sweden)

    Juan Cristóbal Conde-Pérezprina

    2012-01-01

    Full Text Available The mechanisms that concern DNA repair have been studied in the last years due to their consequences in cellular homeostasis. The diverse and damaging stimuli that affect DNA integrity, such as changes in the genetic sequence and modifications in gene expression, can disrupt the steady state of the cell and have serious repercussions to pathways that regulate apoptosis, senescence, and cancer. These altered pathways not only modify cellular and organism longevity, but quality of life (“health-span”. The DNA mismatch repair system (MMR is highly conserved between species; its role is paramount in the preservation of DNA integrity, placing it as a necessary focal point in the study of pathways that prolong lifespan, aging, and disease. Here, we review different insights concerning the malfunction or absence of the DNA-MMR and its impact on cellular homeostasis. In particular, we will focus on DNA-MMR mechanisms regulated by known repair proteins MSH2, MSH6, PMS2, and MHL1, among others.

  15. Ultraviolet rays hardening type material which can do the repair of FRP it is easy; Kantan ni FRP no hoshu ga dekiru shigaisen kokagata zairyo

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-09-15

    The seat-shaped ultraviolet rays (UV) hardening type material which the reinforcement of the fiber strengthening plastic (FRP) and the repair and the corrosion partial repair of the steel rice are made easily in is developed, is sold in late April. The same product is the seat, which made soak an UV hardening type plastic in the fiberglass. Though a un-saturation polyester plastic was adopted, as for many FRP repair materials, a tolerance to the medicine, shock, heat rose by adopting plastic, and the adhesion power became strong, too. And, because it is a seat-shaped, a hand lei rise which takes a plastic and hardening medicine in its hand and to mix is compared with the way of repairing it, and the strength of the repair point becomes uniform with constructing it easily in a short time, too. The car and the port business world are wide except for the construction, and the same company plans sales promotion. (translated by NEDO)

  16. Rotator cuff repair in the Brazilian Unified Health System: Brazilian trends from 2003 to 2015

    Directory of Open Access Journals (Sweden)

    Eduardo Angeli Malavolta

    Full Text Available ABSTRACT OBJECTIVE: To assess the historical trend of rotator cuff repairs in Brazil between 2003 and 2015, using the database of the Brazilian Unified Health System's (Sistema Único de Saúde [SUS] Department of Informatics (DataSUS. METHODS: Historical series using DataSUS. Surgeries performed between 2003 and 2015 were included and data relating to cuff tear repair were assessed, including decompression procedures were included. The numerator was the total number of rotator cuff repair and the denominator, the total population of the assessed locality. Population data were based on information from the Instituto Brasileiro de Geografia e Estatística (IBGE. RESULTS: During the period, 50,207 surgeries were performed. The rate was presented as number of procedures per 100,000 inhabitants, and increased from 0.83 to 2.81, a growth of 238%. In 2015, the South region had the highest rate, 6.32, followed by the Southeast, 3.62, while the North had the lowest rate, 0.13. The growing trend can be observed in the Southeast, South, and Midwest, while the rate is stable in the North and Northeast. CONCLUSION: The rate of rotator cuff repairs in Brazil performed through the SUS increased from 0.83 to 2.81 between 2003 and 2015, representing a growth of 238%, but remains lower than that of developed countries. A trend of growth can be observed in the Southeast, South, and Midwest, while the rate is stable in the North and Northeast.

  17. Y-12 Integrated Materials Management System

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-06-03

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

  18. Y-12 Integrated Materials Management System

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  19. Techniques for remote maintenance of in-cell material-handling system in the HFEF/N main cell

    International Nuclear Information System (INIS)

    Tobias, D.A.; Frickey, C.A.

    1975-01-01

    Operations in the main cell of HFEF/N have required development of remote handling equipment and unique techniques for maintaining the in-cell material-handling system. Specially designed equipment is used to remove a disabled crane or electromechanical manipulator bridge from its support rails and place it on floor stands for repair or maintenance. Support areas for the main cell, such as the spray chamber and hot repair area, provide essential decontamination, repair, and staging areas for the in-cell material-handling-system equipment and tools. A combined engineering and technical effort in upgrading existing master-slave manipulators has definitely reduced the requirements for their maintenance. The cell is primarily for postirradiation examination of LMFBR materials and fuel elements

  20. On Using Materiality in Information Systems Development

    DEFF Research Database (Denmark)

    Carugati, Andrea

    This research brief presents a discussion on the use of the concept of materiality and material knowing in information systems development (ISD). The discussion addresses some of the practical problems still plaguing ISD, augmenting existing ISD methodologies with contributions from systems theory...... as scaffold of knowledge. Through the example taken from a case study of a complex and innovative systems development we outline two design principles to be embedded in modular fashion in ISD processes: (1) whenever possible start ISD efforts by developing a graphical simulator of the material environment...

  1. Efficiency analysis system of material management

    Directory of Open Access Journals (Sweden)

    Bogusław Śliwczyński

    2012-12-01

    Full Text Available Background: Significant scope of enterprise's efficiency management is improving of material management process both the strategic and operational level. The complexity of material flow processes can lead to a threat such as distraction and disintegration of analysis focusing on many different factors influenced on effective sourcing and procurement management, transport and warehousing processes, inventory management, working capital and cash flow management. Material and methods: The presented article focuses on multidimensional and multi-criteria analysis of material management efficiency that is considered as decision support system. Authors have presented results of the research regarding ineffective material management confirm insufficient analytical supporting in various decisions of procurement operations. Results and conclusions: Based on research results authors presented in the article model of efficiency analysis system of material management.

  2. MHSS: a material handling system simulator

    Energy Technology Data Exchange (ETDEWEB)

    Pomernacki, L.; Hollstien, R.B.

    1976-04-07

    A Material Handling System Simulator (MHSS) program is described that provides specialized functional blocks for modeling and simulation of nuclear material handling systems. Models of nuclear fuel fabrication plants may be built using functional blocks that simulate material receiving, storage, transport, inventory, processing, and shipping operations as well as the control and reporting tasks of operators or on-line computers. Blocks are also provided that allow the user to observe and gather statistical information on the dynamic behavior of simulated plants over single or replicated runs. Although it is currently being developed for the nuclear materials handling application, MHSS can be adapted to other industries in which material accountability is important. In this paper, emphasis is on the simulation methodology of the MHSS program with application to the nuclear material safeguards problem. (auth)

  3. Information systems for materials performance

    International Nuclear Information System (INIS)

    Roberge, P.

    1999-01-01

    The rapid development of accessible computing power in the 1980s has led to the use of machine intelligence in every sphere of engineering. The incredible progress in computing power and availability has also created a tremendous wealth of information available at the touch of few buttons. However, such wealth can easily provoke what is commonly described as 'information overload'. The massive number of connections produced by a single search of the web, for example, can greatly overwhelm users of this new technology. The rapidity of Web searches is due to the synergy between progress made in network connectivity protocols, intelligent search strategies and supporting hardware. This paper will attempt to define the basic elements of machine intelligence in the context of corrosion engineering and examine what has been done or could be done to introduce artificial thinking into daily operations. This paper will also review some modem software systems commonly used for information processing and internet searches. (author)

  4. Ceramic material suitable for repair of a space vehicle component in a microgravity and vacuum environment, method of making same, and method of repairing a space vehicle component

    Science.gov (United States)

    Riedell, James A. (Inventor); Easler, Timothy E. (Inventor)

    2009-01-01

    A precursor of a ceramic adhesive suitable for use in a vacuum, thermal, and microgravity environment. The precursor of the ceramic adhesive includes a silicon-based, preceramic polymer and at least one ceramic powder selected from the group consisting of aluminum oxide, aluminum nitride, boron carbide, boron oxide, boron nitride, hafnium boride, hafnium carbide, hafnium oxide, lithium aluminate, molybdenum silicide, niobium carbide, niobium nitride, silicon boride, silicon carbide, silicon oxide, silicon nitride, tin oxide, tantalum boride, tantalum carbide, tantalum oxide, tantalum nitride, titanium boride, titanium carbide, titanium oxide, titanium nitride, yttrium oxide, zirconium diboride, zirconium carbide, zirconium oxide, and zirconium silicate. Methods of forming the ceramic adhesive and of repairing a substrate in a vacuum and microgravity environment are also disclosed, as is a substrate repaired with the ceramic adhesive.

  5. Impact of DNA mismatch repair system alterations on human fertility and related treatments.

    Science.gov (United States)

    Hu, Min-hao; Liu, Shu-yuan; Wang, Ning; Wu, Yan; Jin, Fan

    2016-01-01

    DNA mismatch repair (MMR) is one of the biological pathways, which plays a critical role in DNA homeostasis, primarily by repairing base-pair mismatches and insertion/deletion loops that occur during DNA replication. MMR also takes part in other metabolic pathways and regulates cell cycle arrest. Defects in MMR are associated with genomic instability, predisposition to certain types of cancers and resistance to certain therapeutic drugs. Moreover, genetic and epigenetic alterations in the MMR system demonstrate a significant relationship with human fertility and related treatments, which helps us to understand the etiology and susceptibility of human infertility. Alterations in the MMR system may also influence the health of offspring conceived by assisted reproductive technology in humans. However, further studies are needed to explore the specific mechanisms by which the MMR system may affect human infertility. This review addresses the physiological mechanisms of the MMR system and associations between alterations of the MMR system and human fertility and related treatments, and potential effects on the next generation.

  6. Biopolymer-based hydrogels as injectable materials for tissue repair scaffolds

    International Nuclear Information System (INIS)

    Fiejdasz, Sylwia; Szczubiałka, Krzysztof; Lewandowska-Łańcucka, Joanna; Nowakowska, Maria; Osyczka, Anna M

    2013-01-01

    The progress in tissue regeneration is strongly dependent on the development of biocompatible materials with properties resembling those of a native tissue. Also, the application of noninvasive methods of delivering the scaffold into the tissue defect is of great importance. In this study we present a group of biopolymer-based materials as potential injectable scaffolds. In contrast to other studies involving collagen neutralization or additional incubation of gel in genipin solution, we propose collagen and collagen–chitosan gels crosslinked in situ with genipin. Since some parameters of the cells should be considered in the microscale, the steady-state fluorescence anisotropy was applied to study the microenvironment of the gels. To our knowledge we are the first to report on microrheological properties, such as gel time and microviscosity, for this group of hydrogels. Rapid gelation at physiological temperatures found makes these materials of special interest in applications requiring gel injectability. Physico-chemical investigation showed the influence of the crosslinking agent concentration and chitosan addition on the crosslinking degree, swelling ratio, gel microviscosity, and the degradation rate. Strong correlation was revealed between the surface wettability and the viability of cultured mesenchymal stem cells. Cytotoxicity studies indicated that the collagen–chitosan hydrogels showed the best biocompatibility. (paper)

  7. Ability of Bacillus subtilis protoplasts to repair irradiated bacteriophage deoxyribonucleic acid via acquired and natural enzymatic systems

    International Nuclear Information System (INIS)

    Yasbin, R.E.; Andersen, B.J.; Sutherland, B.M.

    1981-01-01

    A novel form of enzyme therapy was achieved by utilizing protoplasts of Bacillus subtilis. Photoreactivating enzyme of Escherichia coli was successfully inserted into the protoplasts of B. subtilis treated with polyethylene glycol. This enzyme was used to photoreactivate ultraviolet-damaged bacteriophage deoxyribonucleic acid (DNA). Furthermore, in polyethylene glycol-treated protoplasts, ultraviolet-irradiated transfecting bacteriophage DNA was shown to be a functional substrate for the host DNA excision repair system. Previous results (R.E. Yasbin, J.D. Fernwalt, and P.I. Fields, J. Bacteriol.; 137: 391-396) showed that ultraviolet-irradiated bacteriophage DNA could not be repaired via the excision repair system of competent cells. Therefore, the processing of bacteriophage DNA by protoplasts and by competent cells must be different. This sensitive protoplast assay can be used to identify and to isolate various types of DNA repair enzymes

  8. Structural Materials for Efficient Energy Production Systems

    International Nuclear Information System (INIS)

    Gomez Briceno, D.

    2009-01-01

    Increasing the efficiency of electric power production systems implies increasing the operating temperature above those of systems currently in operation. The viability of new systems depends completely on the availability of structural materials that withstand the operating conditions specified in the design: adequate features under mechanical stress at high temperatures and compatibility with the medium. In the case of nuclear systems (fission, fusion), an important requirement is their response to irradiation induced damage. In spite of the significant differences that exist in the design of nuclear power plants, fusion reactors, innovative fission systems, supercritical fossil plants, biomass plants, solar concentration thermal plants, etc., all of them have as a common characteristic the use of resistant materials at high temperatures. The qualification of existing materials for the new and more demanding operating conditions and the development of new materials is one of the challenges faced by the electric power production industry. The science of materials and the understanding of the basic processes that take place in structural materials on exposure to the operating conditions of energy production systems are the tools that are available to obtain safe and economically viable solutions. (Authors) 4 refs.

  9. Performance analysis of nuclear materials accounting systems

    International Nuclear Information System (INIS)

    Cobb, D.D.; Shipley, J.P.

    1979-01-01

    Techniques for analyzing the level of performance of nuclear materials accounting systems in terms of the four performance measures, total amount of loss, loss-detection time, loss-detection probability, and false-alarm probability, are presented. These techniques are especially useful for analyzing the expected performance of near-real-time (dynamic) accounting systems. A conservative estimate of system performance is provided by the CUSUM (cumulative summation of materials balances) test. Graphical displays, called performance surfaces, are developed as convenient tools for representing systems performance, and examples from a recent safeguards study of a nuclear fuels reprocessing plant are given. 6 refs

  10. Reliability modelling of repairable systems using Petri nets and fuzzy Lambda-Tau methodology

    International Nuclear Information System (INIS)

    Knezevic, J.; Odoom, E.R.

    2001-01-01

    A methodology is developed which uses Petri nets instead of the fault tree methodology and solves for reliability indices utilising fuzzy Lambda-Tau method. Fuzzy set theory is used for representing the failure rate and repair time instead of the classical (crisp) set theory because fuzzy numbers allow expert opinions, linguistic variables, operating conditions, uncertainty and imprecision in reliability information to be incorporated into the system model. Petri nets are used because unlike the fault tree methodology, the use of Petri nets allows efficient simultaneous generation of minimal cut and path sets

  11. Involvement of the DNA mismatch repair system in cisplatin sensitivity of testicular germ cell tumours

    DEFF Research Database (Denmark)

    Rudolph, Christiane; Melau, Cecilie; Nielsen, John E.

    2017-01-01

    in the majority of tumours, although the underlying mechanism largely remains to be elucidated. The aim of this study was to investigate the role of the DNA mismatch repair (MMR) system in the cisplatin sensitivity of TGCT. MethodsThe expression pattern of key MMR proteins, including MSH2, MSH6, MLH1 and PMS2...... proteins, in particular MSH2 and MLH1, which are involved in the recognition of cisplatin adducts and in activation of the DNA damage response pathway to initiate apoptosis....

  12. Buried waste containment system materials. Final Report

    International Nuclear Information System (INIS)

    Weidner, J.R.; Shaw, P.G.

    1997-10-01

    This report describes the results of a test program to validate the application of a latex-modified cement formulation for use with the Buried Waste Containment System (BWCS) process during a proof of principle (POP) demonstration. The test program included three objectives. One objective was to validate the barrier material mix formulation to be used with the BWCS equipment. A basic mix formula for initial trials was supplied by the cement and latex vendors. The suitability of the material for BWCS application was verified by laboratory testing at the Idaho National Engineering and Environmental Laboratory (INEEL). A second objective was to determine if the POP BWCS material emplacement process adversely affected the barrier material properties. This objective was met by measuring and comparing properties of material prepared in the INEEL Materials Testing Laboratory (MTL) with identical properties of material produced by the BWCS field tests. These measurements included hydraulic conductivity to determine if the material met the US Environmental Protection Agency (EPA) requirements for barriers used for hazardous waste sites, petrographic analysis to allow an assessment of barrier material separation and segregation during emplacement, and a set of mechanical property tests typical of concrete characterization. The third objective was to measure the hydraulic properties of barrier material containing a stop-start joint to determine if such a feature would meet the EPA requirements for hazardous waste site barriers

  13. Structural materials for innovative nuclear systems (SMINS)

    International Nuclear Information System (INIS)

    2008-01-01

    Structural materials research is a field of growing relevance in the nuclear sector, especially for the different innovative reactor systems being developed within the Generation IV International Forum (GIF), for critical and subcritical transmutation systems, and of interest to the Global Nuclear Energy Partnership (GNEP). Under the auspices of the NEA Nuclear Science Committee (NSC) the Workshop on Structural Materials for Innovative Nuclear Systems (SMINS) was organised in collaboration with the Forschungszentrum Karlsruhe in Germany. The objectives of the workshop were to exchange information on structural materials research issues and to discuss ongoing programmes, both experimental and in the field of advanced modelling. These proceedings include the papers and the poster session materials presented at the workshop, representing the international state of the art in this domain. (author)

  14. Corrosion evaluation of service water system materials

    International Nuclear Information System (INIS)

    Stein, A.A.; Felder, C.M.; Martin, R.L.

    1994-01-01

    The availability and reliability of the service water system is critical for safe operation of a nuclear power plant. Degradation of the system piping and components has forced utilities to re-evaluate the corrosion behavior of current and alternative system materials, to support assessments of the remaining service life of the service water system, selection of replacement materials, implementation of corrosion protection methods and corrosion monitoring programs, and identification of maintenance and operational constraints consistent with the materials used. TU Electric and Stone and Webster developed a service water materials evaluation program for the Comanche Peak Steam Electric Station. Because of the length of exposure and the generic interest in this program by the nuclear power industry, EPRI joined TU to co-sponsor the test program. The program was designed to evaluate the corrosion behavior of current system materials and candidate replacement materials and to determine the operational and design changes which could improve the corrosion performance of the system. Although the test program was designed to be representative of service water system materials and environments targeted to conditions at Comanche Peak, these conditions are typical of and relevant to other fresh water cooled nuclear service water systems. Testing was performed in raw water and water treated with biocide under typical service water operating conditions including continuous flow, intermittent flow, and stagnant conditions. The test program evaluated the 300 Series and 6% molybdenum stainless steels, copper-nickel, titanium, carbon steel, and a formed-in-place nonmetallic pipe lining to determine susceptibility to general, crevice, and microbiologically influenced corrosion and pitting attack. This report presents the results of the test program after 4 years of exposure

  15. Double Retort System for Materials Compatibility Testing

    International Nuclear Information System (INIS)

    V. Munne; EV Carelli

    2006-01-01

    With Naval Reactors (NR) approval of the Naval Reactors Prime Contractor Team (NRPCT) recommendation to develop a gas cooled reactor directly coupled to a Brayton power conversion system as the Space Nuclear Power Plant (SNPP) for Project Prometheus (References a and b) there was a need to investigate compatibility between the various materials to be used throughout the SNPP. Of particular interest was the transport of interstitial impurities from the nickel-base superalloys, which were leading candidates for most of the piping and turbine components to the refractory metal alloys planned for use in the reactor core. This kind of contamination has the potential to affect the lifetime of the core materials. This letter provides technical information regarding the assembly and operation of a double retort materials compatibility testing system and initial experimental results. The use of a double retort system to test materials compatibility through the transfer of impurities from a source to a sink material is described here. The system has independent temperature control for both materials and is far less complex than closed loops. The system is described in detail and the results of three experiments are presented

  16. Standards for pipelines repairs approval through composite sleeves materials; Criterios para aceitacao de reparos em dutos atraves de luvas de material composito

    Energy Technology Data Exchange (ETDEWEB)

    Bayer, Richard Foerster; Bifulco, Antonio C.; Vilani, Eduardo C. [Rust Engenharia Ltda., Diadema, SP (Brazil)

    2005-07-01

    The current paper presents the standards that define the test demanded by the technical specifications set for the evaluation of composite sleeves repairs for steel industrial ducts and pipelines, as well as their forecasted results. Practical comments are given about the adhesion, tensile strength, interlaminate shear resistance, impact, hardness, circumferential elasticity modulus, axial elasticity modulus, and the poison ratio rests, as well as the interpretation of those demands are also discussed. Explains the repair project and the procedure to be followed importance, and why qualified personnel are necessary to install it. The repair project and the procedure, as well as the repair construction effectiveness are verified by hydrostatics testes in tubular specimens. (author)

  17. Materials handbook for fusion energy systems

    Science.gov (United States)

    Davis, J. W.; Marchbanks, M. F.

    A materials data book for use in the design and analysis of components and systems in near term experimental and commercial reactor concepts has been created by the Office of Fusion Energy. The handbook is known as the Materials Handbook for Fusion Energy Systems (MHFES) and is available to all organizations actively involved in fusion related research or system designs. Distribution of the MHFES and its data pages is handled by the Hanford Engineering Development Laboratory (HEDL), while its direction and content is handled by McDonnell Douglas Astronautics Company — St. Louis (MDAC-STL). The MHFES differs from other handbooks in that its format is geared more to the designer and structural analyst than to the materials scientist or materials engineer. The format that is used organizes the handbook by subsystems or components rather than material. Within each subsystem is information pertaining to material selection, specific material properties, and comments or recommendations on treatment of data. Since its inception a little more than a year ago, over 80 copies have been distributed to over 28 organizations consisting of national laboratories, universities, and private industries.

  18. Handbook of adhesive bonded structural repair

    CERN Document Server

    Wegman, Raymond F

    1992-01-01

    Provides repair methods for adhesive bonded and composite structures; identifies suitable materials and equipment for repairs; describes damage evaluation criteria and techniques, and methods of inspection before and after repair.

  19. Ureolytic/Non-Ureolytic Bacteria Co-Cultured Self-Healing Agent for Cementitious Materials Crack Repair

    Directory of Open Access Journals (Sweden)

    Hyeong Min Son

    2018-05-01

    Full Text Available The present study investigated the CaCO3 precipitation performance of ureolytic and non-ureolytic bacteria co-cultured as a self-healing agent for cementitious materials crack repair. Three different inoculum ratios of ureolytic Sporosarcina pasteurii and non-ureolytic Bacillus thuringiensis (10:0, 8:2, or 5:5 were used. The effect of coculturing ureolytic and non-ureolytic bacteria on microbial metabolism was investigated by measuring the rate of growth in urea-containing medium and the rate of NH4+ and CaCO3 production in urea–calcium lactate medium. The self-healing efficiency of co-cultured bacteria was examined by exposing cement mortar specimens with predefined cracks to media containing single urease-producing or co-cultured bacteria. The obtained results provide new findings, where CaCO3 precipitation is improved by co-culturing ureolytic and non-ureolytic bacteria, owing to the relatively faster growth rate of non-ureolytic bacteria. The crack filling rate correlated with the width of crack, in particular, specimens with a smaller crack width showed the faster filling effect, indicating that the crack width can be a dominant factor influencing the CaCO3 precipitation capacity of co-cultured bacteria.

  20. Climate control systems using pozzolan materials

    KAUST Repository

    Almadhoun, Mahmoud Nassar Mahmoud

    2016-02-18

    A system and method for conditioning air is provided that optimizes the use of sustainable and locally sourced materials with agrarian, residential, and industrial applications. The system can be formed with a porous siliceous, or siliceous and aluminous material that is sufficiently porous, to allow conditioning fluid to flow there through. The material can also be formed into a structure that includes one or more passageways configured to allow air to be conditioned to also pass there through. The structure can be configured to cause the conditioning fluid passing through the porous portions of the structure to intersect and mix with air passing there through. The structure may include a plurality of passageways and intersections and may include a plurality of air inlets and outlets for air passage. The system may additionally include a means for storing, collecting, and driving conditioning fluid through the system and a means for collecting solar radiation to drive airflow and regenerate conditioning fluid.

  1. [The quality of patient care under the German DRG system using as example the inguinal hernia repair].

    Science.gov (United States)

    Rudroff, C; Schweins, M; Heiss, M M

    2008-02-01

    The DRG system in Germany was introduced to improve and at the same time simplify the reimbursement of costs in German hospitals. Cost effectiveness and economic efficiency were the declared goals. Structural changes and increased competition among different hospitals were the consequences. The effect on the qualitiy of patient care has been discussed with some concern. Furthermore, doubts have been expressed about the correct representation of the various diagnoses and treatments in the coding system and the financial revenue. Inguinal hernia repair serves as an example to illustrate some common problems with the reimbursement in the DRG system. Virtual patients were grouped using a "Web Grouper" and analysed using the cost accounting from the G-DRG-Browser of the InEK. Additionally, the reimbursement for ambulant hernia repair was estimated. The DRG coding did not differentiate the various operative procedures for inguinal hernia repair. They all generated the same revenues. For example, the increased costs for bilateral inguinal hernia repair are not represented in the payment. Furthermore, no difference is made between primary and recurrent inguinal hernia. In the case of a short-term hospital stay, part of the revenue is retained. In the case of ambulatory treatment of inguinal hernia, the reimbursement is by far not a real compensation for the actual costs. The ideal patient in the DRG system suffers from a primary inguinal hernia, undergoes an open hernia repair without mesh, and remains for 2-3 days in hospital. Minimally invasive procedures, repair of bilateral inguinal hernia and ambulant operation are by far less profitable--if at all. The current revenues for inguinal hernia repair require improvement and adjustment to reality in order to accomplish the goals which the DRG system in Germany aims at.

  2. A Mobile Robotic System for the Inspection and Repair of SG Tubes in NPPs

    Directory of Open Access Journals (Sweden)

    Yong-Chil Seo

    2016-04-01

    Full Text Available The reliability and performance of a steam generator (SG is one of the serious concerns in the operation of pressurized water nuclear power plants. Because of high levels of radiation, robotic systems have been used to inspect and repair SG tubes. In this paper, we present a mobile robotic system that positions the inspection and repair tools while hanging down from the tube sheets where the tubes are fixed. All of the driving mechanisms of the mobile robot are actuated by electric motors to start its works, providing that the electric power is prepared without the additional need for an on-site air services. A special tube-holding mechanism with a high holding force has been developed to prevent falling from the tube sheets, even in the case of an electric power failure. We have also developed a quick installation guide device that guides the mobile robot to desired initial positions in the tube sheet exactly and quickly, which helps to reduce the radiation exposure of human workers during the installation work. This paper also provides on-site experimental results and lessons learned.

  3. Repair of walls of coke ovens with a volume of 41. 6 m/sup 3/

    Energy Technology Data Exchange (ETDEWEB)

    Pyatnitsa, V.A.; Bulyga, N.I.

    1988-11-01

    Discusses repair of coke oven walls and the heating system of a battery with coke ovens 7.0 m high in the Avdeevka plant. The following problems are evaluated: types of wall deformation and wear, distribution of wear zones, zones with maximum wear, coke oven repair without cooling and with cooling, repair of cracks in oven walls, effects of wall temperature (in schemes without cooling) on repair, behavior of walls in zones of temperature differences, sequence of repair operations, repair of heating channels, specific problems of wall repair at the machine side and at the pusher side of a coke oven battery, methods for reducing repair time, materials used for coke oven repair.

  4. Nuclear Space Power Systems Materials Requirements

    International Nuclear Information System (INIS)

    Buckman, R.W. Jr.

    2004-01-01

    High specific energy is required for space nuclear power systems. This generally means high operating temperatures and the only alloy class of materials available for construction of such systems are the refractory metals niobium, tantalum, molybdenum and tungsten. The refractory metals in the past have been the construction materials selected for nuclear space power systems. The objective of this paper will be to review the past history and requirements for space nuclear power systems from the early 1960's through the SP-100 program. Also presented will be the past and present status of refractory metal alloy technology and what will be needed to support the next advanced nuclear space power system. The next generation of advanced nuclear space power systems can benefit from the review of this past experience. Because of a decline in the refractory metal industry in the United States, ready availability of specific refractory metal alloys is limited

  5. Development of radioactive materials inspection system

    International Nuclear Information System (INIS)

    Yang Lu; Wang Guobao; Chen Yuhua; Li Latu; Zhang Sujing

    2005-01-01

    Radioactive materials inspection system which is applied to inspect the horror activities of radioactive materials and its illegal transfer. The detector sections are made of highly stable and credible material. It has high sensitivity to radioactive materials. The inspect lowest limit of inspection is the 2-3 times to the background, the energy range is 30 keV-2.5 MeV and the response time is 0.5 s. Inspection message can be transmitted through wired or wireless web to implement remote control. The structure of the system is small, light and convenient. It is ideal for protecting society and public from the harm of the radiation. (authors)

  6. Advanced materials for space nuclear power systems

    International Nuclear Information System (INIS)

    Titran, R.H.; Grobstein, T.L.

    1991-01-01

    Research on monolithic refractory metal alloys and on metal matrix composites is being conducted at the NASA Lewis Research Center, Cleveland, Ohio, in support of advanced space power systems. The overall philosophy of the research is to develop and characterize new high-temperature power conversion and radiator materials and to provide spacecraft designers with material selection options and design information. Research on three candidate materials (carbide strengthened niobium alloy PWC-11 for fuel cladding, graphite fiber reinforced copper matrix composites (Gr/Cu) for heat rejection fins, and tungsten fiber reinforced niobium matrix composites (W/NB) for fuel containment and structural supports) considered for space power system applications is discussed. Each of these types of materials offers unique advantages for space power applications

  7. Structural materials challenges for fusion power systems

    International Nuclear Information System (INIS)

    Kurtz, Richard J.

    2009-01-01

    Full text: Structural materials in a fusion power system must function in an extraordinarily demanding environment that includes various combinations of high temperatures, reactive chemicals, time-dependent thermal and mechanical stresses, and intense damaging radiation. The fusion neutron environment produces displacement damage equivalent to displacing every atom in the material about 150 times during its expected service life, and changes in chemical composition by transmutation reactions, which includes creation of reactive and insoluble gases. Fundamental materials challenges that must be resolved to effectively harness fusion power include (1) understanding the relationships between material strength, ductility and resistance to cracking, (2) development of materials with extraordinary phase stability, high-temperature strength and resistance to radiation damage, (3) establishment of the means to control corrosion of materials exposed to aggressive environments, (4) development of technologies for large-scale fabrication and joining, and (5) design of structural materials that provide for an economically attractive fusion power system while simultaneously achieving safety and environmental acceptability goals. The most effective approach to solve these challenges is a science-based effort that couples development of physics-based, predictive models of materials behavior with key experiments to validate the models. The U.S. Fusion Materials Sciences program is engaged in an integrated effort of theory, modeling and experiments to develop structural materials that will enable fusion to reach its safety, environmental and economic competitiveness goals. In this presentation, an overview of recent progress on reduced activation ferritic/martensitic steels, nanocomposited ferritic alloys, and silicon carbide fiber reinforced composites for fusion applications will be given

  8. US national material control and accounting system

    International Nuclear Information System (INIS)

    Smith, C.N.

    1984-01-01

    The State System of Accounting and Control (SSAC) for fuel cycle facilities in the licensed, commercial sector of the US nuclear community, and details of the material control and accounting measures dealing with the national safeguards program are discussed. The concept and role of the Fundamental Nuclear Material Control (FNMC) Plan is discussed. Also, the relationship between the national safeguards program and the international safeguards program of the US SSAC are described

  9. Sensor-based material tagging system

    International Nuclear Information System (INIS)

    Vercellotti, L.C.; Cox, R.W.; Ravas, R.J.; Schlotterer, J.C.

    1991-01-01

    Electronic identification tags are being developed for tracking material and personnel. In applying electronic identification tags to radioactive materials safeguards, it is important to measure attributes of the material to ensure that the tag remains with the material. The addition of a microcontroller with an on-board analog-to-digital converter to an electronic identification tag application-specific integrated-circuit has been demonstrated as means to provide the tag with sensor data. Each tag is assembled into a housing, which serves as a scale for measuring the weight of a paint-can-sized container and its contents. Temperature rise of the can above ambient is also measured, and a piezoelectric detector detects disturbances and immediately puts the tag into its alarm and beacon mode. Radiation measurement was also considered, but the background from nearby containers was found to be excessive. The sensor-based tagging system allows tracking of the material in cans as it is stored in vaults or is moved through the manufacturing process. The paper presents details of the sensor-based material tagging system and describes a demonstration system

  10. An assessment of composite repair system in offshore platform for corroded circumferential welds in super duplex steel pipe

    Directory of Open Access Journals (Sweden)

    Silvio de Barros

    2018-04-01

    Full Text Available The main aim of this study is to assess the effectiveness of a composite repair system in severely corroded circumferential welds in super duplex stainless steel pipes as a preventive measure against the premature corrosion damage at the welds. Artificial defects were fabricated on the super duplex steel tube in order to reproduce the localized corrosion damage defects found in real welded joints. Three kinds of through thickness defects were considered: 25%, 50% and 96% of the perimeter of the pipe. The performance of the repaired pipe was assessed by hydrostatic tests as per ISO 24817 standard. The results showed that the composite repair system can sustain the designed failure pressure even for the pipe damaged with through-wall defect up to 96% of the perimeter of the pipe. Hence, the composite repair system can be used as a preliminary tool to protect the unexpected or premature failure at the welds and maintain an adequate level of mechanical strength for a given operating pressure. This composite repair system can assure that the pipe will not leak until a planned maintenance of the line. Nevertheless, further work is still desirable to improve the confidence in the long-term performance of bonded composite

  11. Atucha I nuclear power plant: repair works in QK02W01 moderator system heat exchanger

    International Nuclear Information System (INIS)

    Olivieri, Luis E.; Zanni, Pablo A.

    2000-01-01

    Atucha I nuclear power plant moderator system operates with highly radioactive heavy water, a pressure of 115 Bar and temperatures of about 200 C degrees. In March 2000, an increasing leakage of heavy water to the conventional thermal circuit was detected, conducting the plant to a shut down. The development of a number of actions and measures were taken, in order to plug this leakage. The leakage was found in a heat exchanger, which is located in a place of difficult access, with a high radiological yield and which, according to design, it was not considered to be mechanically repaired. It is a U bend tubes heat exchanger, weighting about 20 tons, and with a heavy water flow of 800 tons/h on the primary circuit, and 950 tons/h of ordinary water on the secondary side. Foreseeing this event, it had been designed and constructed special equipment and procedures, by means of a contract, with the Company INVAP SA. Repair works were carried out within a period of eighty-six (86) days, from which, forty five days were used to repair the component itself. A considerable amount of time was used to prepare simulators and the training of personnel. Due to the high radiological yield and the strict care of radiological standards, it was necessary the participation of 300 persons, integrating a collective dose of 4,86 Sv-m. It was necessary the construction of platforms and auxiliary stairs so as to make the work place accessible, as well as lifting and movement devices for heavy components, since this area does not have such kind of facilities. Welding and cutting machines remote controlled as well as manipulators which operated in front of the exchanger tube sheet were used. The aim was the reduction of dose values as much as possible. Special shielding were developed and in some cases it was necessary the adoption of drastic measures such as the cutting of bolts or pipes. The failure was detected and the tube was plugged. Also were plugged those tubes with wall thickness

  12. [A medical consumable material management information system].

    Science.gov (United States)

    Tang, Guoping; Hu, Liang

    2014-05-01

    Medical consumables material is essential supplies to carry out medical work, which has a wide range of varieties and a large amount of usage. How to manage it feasibly and efficiently that has been a topic of concern to everyone. This article discussed about how to design a medical consumable material management information system that has a set of standardized processes, bring together medical supplies administrator, suppliers and clinical departments. Advanced management mode, enterprise resource planning (ERP) applied to the whole system design process.

  13. A method for the calculation of the cumulative failure probability distribution of complex repairable systems

    International Nuclear Information System (INIS)

    Caldarola, L.

    1976-01-01

    A method is proposed for the analytical evaluation of the cumulative failure probability distribution of complex repairable systems. The method is based on a set of integral equations each one referring to a specific minimal cut set of the system. Each integral equation links the unavailability of a minimal cut set to its failure probability density distribution and to the probability that the minimal cut set is down at the time t under the condition that it was down at time t'(t'<=t). The limitations for the applicability of the method are also discussed. It has been concluded that the method is applicable if the process describing the failure of a minimal cut set is a 'delayed semi-regenerative process'. (Auth.)

  14. A real-time expert system for self-repairing flight control

    Science.gov (United States)

    Gaither, S. A.; Agarwal, A. K.; Shah, S. C.; Duke, E. L.

    1989-01-01

    An integrated environment for specifying, prototyping, and implementing a self-repairing flight-control (SRFC) strategy is described. At an interactive workstation, the user can select paradigms such as rule-based expert systems, state-transition diagrams, and signal-flow graphs and hierarchically nest them, assign timing and priority attributes, establish blackboard-type communication, and specify concurrent execution on single or multiple processors. High-fidelity nonlinear simulations of aircraft and SRFC systems can be performed off-line, with the possibility of changing SRFC rules, inference strategies, and other heuristics to correct for control deficiencies. Finally, the off-line-generated SRFC can be transformed into highly optimized application-specific real-time C-language code. An application of this environment to the design of aircraft fault detection, isolation, and accommodation algorithms is presented in detail.

  15. Evolution and Adaptation in Pseudomonas aeruginosa Biofilms Driven by Mismatch Repair System-Deficient Mutators

    DEFF Research Database (Denmark)

    Luján, Adela M.; Maciá, María D.; Yang, Liang

    2011-01-01

    , which are rarely eradicated despite intensive antibiotic therapy. Current knowledge indicates that three major adaptive strategies, biofilm development, phenotypic diversification, and mutator phenotypes [driven by a defective mismatch repair system (MRS)], play important roles in P. aeruginosa chronic...... infections, but the relationship between these strategies is still poorly understood. We have used the flow-cell biofilm model system to investigate the impact of the mutS associated mutator phenotype on development, dynamics, diversification and adaptation of P. aeruginosa biofilms. Through competition...... diversification, evidenced by biofilm architecture features and by a wider range and proportion of morphotypic colony variants, respectively. Additionally, morphotypic variants generated in mutator biofilms showed increased competitiveness, providing further evidence for mutator-driven adaptive evolution...

  16. Building an adaptive agent to monitor and repair the electrical power system of an orbital satellite

    Science.gov (United States)

    Tecuci, Gheorghe; Hieb, Michael R.; Dybala, Tomasz

    1995-01-01

    Over several years we have developed a multistrategy apprenticeship learning methodology for building knowledge-based systems. Recently we have developed and applied our methodology to building intelligent agents. This methodology allows a subject matter expert to build an agent in the same way in which the expert would teach a human apprentice. The expert will give the agent specific examples of problems and solutions, explanations of these solutions, or supervise the agent as it solves new problems. During such interactions, the agent learns general rules and concepts, continuously extending and improving its knowledge base. In this paper we present initial results on applying this methodology to build an intelligent adaptive agent for monitoring and repair of the electrical power system of an orbital satellite, stressing the interaction with the expert during apprenticeship learning.

  17. Sensitivity analysis of repairable redundant system with switching failure and geometric reneging

    Directory of Open Access Journals (Sweden)

    Chandra Shekhar

    2017-09-01

    Full Text Available This study deals with the performance modeling and reliability analysis of a redundant machining system composed of several functional machines. To analyze the more realistic scenarios, the concepts of switching failure and geometric reneging are included. The time-to-breakdown and repair time of operating and standby machines are assumed to follow the exponential distribution. For the quantitative assessment of the machine interference problem, various performance measures such as mean-time-to-failure, reliability, reneging rate, etc. have been formulated. To show the practicability of the developed model, a numerical illustration has been presented. For the practical justification and validity of the results established, the sensitivity analysis of reliability indices has been presented by varying different system descriptors.

  18. Lethal effects of solar radiation in proficient and deficient bacteria in repair systems

    International Nuclear Information System (INIS)

    Sousa Neto, A. de.

    1980-01-01

    A study of the lethal action of solar radiation on strains of E.coli K12, proficient or deficient in repair systems, as well as the wild type strain gene products are involved in repair of damage induced by solar radiation. The inactivation of the various bacterial strains (normalized to a dose equivalent to radiation at a wavelength 254 nm) suggests that the more energetic wavelengths of the solar spectrum (290-320 nm) could be responsible for the primary damage that occurs in the DNA. The reduction in the shoulder of the survival curve in wild type strains in indicative of induction of sub-lethal damage in this region of the curve. Analysing solar inactivation curves of the bacterial strains (normalised by spore dosimetry) together with those of the same strains irradiated with UV at 254 nm, it was evident that 254 nm is not the ideal wavelength for comparison. This analysis also indicated that in addition to damage to DNA, other factors are involved in the solar radiation inactivation of wild type strains. (author)

  19. An Injury Paradigm to Investigate Central Nervous System Repair in Drosophila

    Science.gov (United States)

    Kato, Kentaro; Hidalgo, Alicia

    2013-01-01

    An experimental method has been developed to investigate the cellular responses to central nervous system (CNS) injury using the fruit-fly Drosophila. Understanding repair and regeneration in animals is a key question in biology. The damaged human CNS does not regenerate, and understanding how to promote the regeneration is one of main goals of medical neuroscience. The powerful genetic toolkit of Drosophila can be used to tackle the problem of CNS regeneration. A lesion to the CNS ventral nerve cord (VNC, equivalent to the vertebrate spinal cord) is applied manually with a tungsten needle. The VNC can subsequently be filmed in time-lapse using laser scanning confocal microscopy for up to 24 hr to follow the development of the lesion over time. Alternatively, it can be cultured, then fixed and stained using immunofluorescence to visualize neuron and glial cells with confocal microscopy. Using appropriate markers, changes in cell morphology and cell state as a result of injury can be visualized. With ImageJ and purposely developed plug-ins, quantitative and statistical analyses can be carried out to measure changes in wound size over time and the effects of injury in cell proliferation and cell death. These methods allow the analysis of large sample sizes. They can be combined with the powerful genetics of Drosophila to investigate the molecular mechanisms underlying CNS regeneration and repair. PMID:23567253

  20. Space Transportation System (STS)-117 External Tank (ET)-124 Hail Damage Repair Assessment

    Science.gov (United States)

    Wilson, Timmy R.; Gentz, Steven J.; Barth, Timothy S.; Minute, Stephen A.; Flowers, Cody P.; Hamilton, David A.; Null, Cynthia H.; Schafer, Charles F.

    2009-01-01

    Severe thunderstorms with associated hail and high winds struck the STS-117 stack on February 26, 2007. Peak winds were recorded at 62 knots with hail sizes ranging from 0.3 inch to 0.8 inch in diameter. As a result of the storm, the North Carolina Foam Institute (NCFI) type 24-124 Thermal Protection System (TPS) foam on the liquid oxygen (LO2) ogive acreage incurred significant impact damage. The NCFI on the ET intertank and the liquid hydrogen (LH2) acreage sustained hail damage. The Polymer Development Laboratory (PDL)-1034 foam of the LO2 ice frost ramps (IFRs) and the Super-Lightweight Ablator (SLA) of the LO2 cable tray also suffered minor damage. NASA Engineering and Safety Center (NESC) was asked to assess the technical feasibility of repairing the ET TPS, the reasonableness of conducting those repairs with the vehicle in a vertical, integrated configuration at the Kennedy Space Center (KSC) Vehicle Assemble Building (VAB), and to address attendant human factors considerations including worker fatigue and the potential for error. The outcome of the assessment is recorded in this document.

  1. Availability of K-out-of-N:G systems with non-identical components subject to repair priorities

    International Nuclear Information System (INIS)

    Khatab, A.; Nahas, N.; Nourelfath, M.

    2009-01-01

    In this paper, a K-out-of-N:G system with N categories of components is studied. Each component category is characterized by its own failure and repair rates. There are R repair facilities, and repair priorities are specified between the N non-identical components. An algorithm for automatic construction of the system state transition diagram is presented. The stationary availability of each component and that of the system are evaluated by using a multi-dimensional Markov model. We show how this model can be represented as a network of stochastic automata with state-dependent transitions that can be implemented via generalized tensor (or Kronecker) algebra. For the efficiency assessment, an analog Monte Carlo simulation model is developed. Experiments are then conducted and simulation results are compared to those obtained by the proposed approach

  2. Dynamic reliability assessment and prediction for repairable systems with interval-censored data

    International Nuclear Information System (INIS)

    Peng, Yizhen; Wang, Yu; Zi, YanYang; Tsui, Kwok-Leung; Zhang, Chuhua

    2017-01-01

    The ‘Test, Analyze and Fix’ process is widely applied to improve the reliability of a repairable system. In this process, dynamic reliability assessment for the system has been paid a great deal of attention. Due to instrument malfunctions, staff omissions and imperfect inspection strategies, field reliability data are often subject to interval censoring, making dynamic reliability assessment become a difficult task. Most traditional methods assume this kind of data as multiple normal distributed variables or the missing mechanism as missing at random, which may cause a large bias in parameter estimation. This paper proposes a novel method to evaluate and predict the dynamic reliability of a repairable system subject to interval-censored problem. First, a multiple imputation strategy based on the assumption that the reliability growth trend follows a nonhomogeneous Poisson process is developed to derive the distributions of missing data. Second, a new order statistic model that can transfer the dependent variables into independent variables is developed to simplify the imputation procedure. The unknown parameters of the model are iteratively inferred by the Monte Carlo expectation maximization (MCEM) algorithm. Finally, to verify the effectiveness of the proposed method, a simulation and a real case study for gas pipeline compressor system are implemented. - Highlights: • A new multiple imputation strategy was developed to derive the PDF of missing data. • A new order statistic model was developed to simplify the imputation procedure. • The parameters of the order statistic model were iteratively inferred by MCEM. • A real cases study was conducted to verify the effectiveness of the proposed method.

  3. Development of a rocking R/C shear wall system implementing repairable structural fuses

    Science.gov (United States)

    Parsafar, Saeed; Moghadam, Abdolreza S.

    2017-09-01

    In the last decades, the concept of earthquake resilient structural systems is becoming popular in which the rocking structure is considered as a viable option for buildings in regions of high seismicity. To this end, a novel wall-base connection based on the " repairable structure" approach is proposed and evaluated. The proposed system is made of several steel plates and high strength bolts act as a friction connection. To achieve the desired rocking motion in the proposed system, short-slotted holes are used in vertical directions for connecting the steel plates to the shear wall (SW). The experimental and numerical studies were performed using a series of displacement control quasi-static cyclic tests on a reference model and four different configurations of the proposed connection installed at the wall corners. The seismic response of the proposed system is compared to the conventional SW in terms of energy dissipation and damage accumulation. In terms of energy dissipation, the proposed system depicted better performance with 95% more energy dissipation capability compared to conventional SW. In terms of damage accumulation, the proposed SW system is nearly undamaged compared to the conventional wall system, which was severely damaged at the wall-base region. Overall, the introduced concept presents a feasible solution for R/C structures when a low-damage design is targeted, which can improve the seismic performance of the structural system significantly.

  4. Joint optimisation of spare part inventory, maintenance frequency and repair capacity for k-out-of-N systems

    NARCIS (Netherlands)

    de Smidt-Destombes, Karin S.; van der Heijden, Matthijs C.; van Harten, Aart

    2009-01-01

    To achieve a high system availability at minimal costs, relevant decisions include the choice of preventive maintenance frequency, spare part inventory levels and spare part repair capacity. We develop heuristics for the joint optimisation of these variables for (a) a single k-out-of-N system under

  5. Thermoelectric Energy Conversion: Materials, Devices, and Systems

    International Nuclear Information System (INIS)

    Chen, Gang

    2015-01-01

    This paper will present a discussion of challenges, progresses, and opportunities in thermoelectric energy conversion technology. We will start with an introduction to thermoelectric technology, followed by discussing advances in thermoelectric materials, devices, and systems. Thermoelectric energy conversion exploits the Seebeck effect to convert thermal energy into electricity, or the Peltier effect for heat pumping applications. Thermoelectric devices are scalable, capable of generating power from nano Watts to mega Watts. One key issue is to improve materials thermoelectric figure- of-merit that is linearly proportional to the Seebeck coefficient, the square of the electrical conductivity, and inversely proportional to the thermal conductivity. Improving the figure-of-merit requires good understanding of electron and phonon transport as their properties are often contradictory in trends. Over the past decade, excellent progresses have been made in the understanding of electron and phonon transport in thermoelectric materials, and in improving existing and identify new materials, especially by exploring nanoscale size effects. Taking materials to real world applications, however, faces more challenges in terms of materials stability, device fabrication, thermal management and system design. Progresses and lessons learnt from our effort in fabricating thermoelectric devices will be discussed. We have demonstrated device thermal-to-electrical energy conversion efficiency ∼10% and solar-thermoelectric generator efficiency at 4.6% without optical concentration of sunlight (Figure 1) and ∼8-9% efficiency with optical concentration. Great opportunities exist in advancing materials as well as in using existing materials for energy efficiency improvements and renewable energy utilization, as well as mobile applications. (paper)

  6. Semi Automated Ferrous Material Scouring System (SAFMSS)

    Science.gov (United States)

    2016-03-14

    Mapping System GPR Ground Penetrating Radar IP Intellectual Property MEC Munitions and Explosives of Concern MPPEH Material Potentially Presenting...the development phase and well aware of the complexity, components and parameters of the system, developed an estimate of $800,000 for the price of...compared the weekly rental fee and the purchase price of excavators. Table 5 below lists the purchase price and weekly rental fee for three different

  7. Left cardiac chambers reverse remodeling after percutaneous mitral valve repair with the MitraClip system.

    Science.gov (United States)

    Scandura, Salvatore; Ussia, Gian Paolo; Capranzano, Piera; Caggegi, Anna; Sarkar, Kunal; Cammalleri, Valeria; Mangiafico, Sarah; Chiarandà, Marta; Immè, Sebastiano; Di Pasqua, Fabio; Pistritto, Anna Maria; Millan, Giovanni; Tamburino, Corrado

    2012-10-01

    Successful mitral valve surgical repair, decreasing volume overload, has been shown to provide reverse left ventricular (LV) and/or left atrial remodeling in most patients. Percutaneous mitral valve repair with the MitraClip system (Abbott, Abbott Park, IL) has been associated with favorable clinical outcomes in patients with mitral regurgitation at high risk of surgery. However, specific data on left cardiac chambers reverse remodeling after such procedures are limited. This was a prospective observational study of consecutive patients at high risk of surgery, with moderate-to-severe or severe mitral regurgitation undergoing MitraClip system implantation. Follow-up echocardiography was performed at 6 months. The evaluated parameters were the LV end-diastolic and end-systolic volume indexes, LV sphericity index, LV ejection fraction, and left atrial volume index. Reverse LV remodeling was defined as a decrease of 10% in the LV end-diastolic volume index. The study population included 44 patients: 14 with degenerative and 30 with functional mitral regurgitation. At 6 months of follow-up, significant reductions in the median and interquartile range of the sphericity index (from 0.57 [interquartile range 0.54-0.62] to 0.54 [interquartile range 0.50-0.58]; P interquartile range 63.0-102.2] to 60.7 mL/m(2) [50.8-84.4]; P interquartile range 28.2-70.5] to 28.9 mL/m(2) [interquartile range 22.2-55.8]; P interquartile range 30.0-55.0%] to 46.0% [interquartile range 35.0-58.0%]; P < .001) from baseline to 6 months. Minor differences in the left atrial volume index were observed. Reverse remodeling, according to the specified definition, was observed in 77.3% of the patients. The present study reports positive LV reshape effects after mitral valve repair with the MitraClip system, showing significant improvements in LV size and function. Copyright © 2012 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.

  8. SYSTEM ORGANIZATION OF MATERIAL PROVIDING OF BUILDING

    Directory of Open Access Journals (Sweden)

    A. V. Rаdkеvich

    2014-04-01

    Full Text Available Purpose. Development of scientific-methodical bases to the design of rational management of material streams in the field of building providing taking into account intersystem connections with the enterprises of building industry. Methodology. The analysis of last few years of functioning of building industry in Ukraine allows distinguishing a number of problems that negatively influence the steady development of building, as the component of the state economics system. Therefore the research of existent organization methods of the system of building objects providing with material resources is extremely necessary. In connection with this the article justifies the use of method of hierarchies analysis (Saati method for finding the optimal task solution of fixing the enterprises of building industry after building objects. Findings. Results give an opportunity to guidance of building organization to estimate and choose advantageous suppliers - enterprises of building industry, to conduct their rating, estimation taking into account basic descriptions, such as: quality, price, reliability of deliveries, specialization, financial status etc. Originality. On the basis of Saati method the methodologies of organization are improved, planning and managements of the reliable system of providing of building necessary material resources that meet the technological requirements of implementation of building and installation works. Practical value. Contribution to the decisions of many intricate organizational problems that are accompanied by the problems of development of building, provided due to organization of the reliable system of purchase of material resources.

  9. Design of POLCA material control systems

    NARCIS (Netherlands)

    Riezebos, J.

    2010-01-01

    POLCA is a material control system designed for make-to-order or engineer-to-order companies. These firms have to cope with a high variety of customised products, and strong pressure to provide short throughput times. POLCA constrains the amount of work in progress on the shop floor in order to

  10. Advanced physical protection systems for nuclear materials

    International Nuclear Information System (INIS)

    Jones, O.E.

    1975-10-01

    Because of the increasing incidence of terrorism, there is growing concern that nuclear materials and facilities need improved physical protection against theft, diversion, or sabotage. Physical protection systems for facilities or transportation which have balanced effectiveness include information systems, access denial systems, adequate and timely response, recovery capability, and use denial methods for despoiling special nuclear materials (SNM). The role of these elements in reducing societal risk is described; however, it is noted that, similar to nuclear war, the absolute risks of nuclear theft and sabotage are basically unquantifiable. Sandia Laboratories has a major Energy Research and Development Administration (ERDA) role in developing advanced physical protection systems for improving the security of both SNM and facilities. These activities are surveyed. A computer simulation model is being developed to assess the cost-effectiveness of alternative physical protection systems under various levels of threat. Improved physical protection equipment such as perimeter and interior alarms, secure portals, and fixed and remotely-activated barriers is being developed and tested. In addition, complete prototype protection systems are being developed for representative nuclear facilities. An example is shown for a plutonium storage vault. The ERDA safe-secure transportation system for highway shipments of all significant quantities of government-owned SNM is described. Adversary simulation as a tool for testing and evaluating physical protection systems is discussed. A list of measures is given for assessing overall physical protection system performance. (auth)

  11. Advanced physical protection systems for nuclear materials

    International Nuclear Information System (INIS)

    Jones, O.E.

    1976-01-01

    Because of the increasing incidence of terrorism, there is growing concern that nuclear materials and facilities need improved physical protection against theft, diversion, or sabotage. Physical protection systems for facilities or transportation which have balanced effectiveness include information systems, access denial systems, adequate and timely response, recovery capability, and use denial methods for despoiling special nuclear materials (SNM). The role of these elements in reducing societal risk is described; however, it is noted that, similar to nuclear war, the absolute risks of nuclear theft and sabotage are basically unquantifiable. Sandia Laboratories has a major US Energy Research and Development Administration (ERDA) role in developing advanced physical protection systems for improving the security of both SNM and facilities. These activities are surveyed in this paper. A computer simulation model is being developed to assess the cost-effectiveness of alternative physical protection systems under various levels of threat. Improved physical protection equipment such as perimeter and interior alarms, secure portals, and fixed and remotely activated barriers is being developed and tested. In addition, complete prototype protection systems are being developed for representative nuclear facilities. An example is shown for a plutonium storage vault. The ERDA safe-secure transportation system for highway shipments of all significant quantities of government-owned SNM is described. Adversary simulation as a tool for testing and evaluating physical protection systems is discussed. Finally, a list of measures is given for assessing overall physical protection system performance. (author)

  12. Passive sensor systems for nuclear material monitoring

    International Nuclear Information System (INIS)

    Simpson, M.L.; Boatner, L.A.; Holcomb, D.E.; McElhaney, S.A.; Mihalczo, J.T.; Muhs, J.D.; Roberts, M.R.; Hill, N.W.

    1993-01-01

    Passive fiber optic sensor systems capable of confirming the presence of special nuclear materials in storage or process facilities are being developed at Oak Ridge National Laboratory (ORNL). These sensors provide completely passive, remote measurement capability. No power supplies, amplifiers, or other active components that could degrade system reliability are required at the sensor location. ORNL, through its research programs in scintillator materials, has developed a variety of materials for use in alpha-, beta-, gamma-, and neutron-sensitive scintillator detectors. In addition to sensors for measuring radiation flux, new sensor materials have been developed which are capable of measuring weight, temperature, and source location. An example of a passive sensor for temperature measurement is the combination of a thermophosphor (e.g., rare-earth activated Y 2 O 3 ) with 6 LiF (95% 6 Li). This combination results in a new class of scintillators for thermal neutrons that absorb energy from the radiation particles and remit the energy as a light pulse, the decay rate of which, over a specified temperature range, is temperature dependent. Other passive sensors being developed include pressure-sensitive triboluminescent materials, weight-sensitive silicone rubber fibers, scintillating fibers, and other materials for gamma and neutron detection. The light from the scintillator materials of each sensor would be sent through optical fibers to a monitoring station, where the attribute quantity could be measured and compared with previously recorded emission levels. Confirmatory measurement applications of these technologies are being evaluated to reduce the effort, costs, and employee exposures associated with inventorying stockpiles of highly enriched uranium at the Oak Ridge Y-12 Plant

  13. Materials used in refrigerated storage system

    Energy Technology Data Exchange (ETDEWEB)

    Abakians, H

    1970-09-01

    Applications of cryogenic technology have increased at a phenomenal rate during the past decade. With the installation of a number of refrigerated storage tanks in Iran, e.g., LPG storage at Bandar Mah Shahr and Kharg Is., and ammonia storage at Bandar Shahpour, it is appropriate to review the materials used in constructing low temperature storage systems. In order to have an economical fully refrigerated storage installation without assuming the risk of brittle fracture, appropriate notch-tough material should be selected for the important and highly stressed components. In general, the lower the operating temperature, the more expensive is the material to be used. Hence, care should be taken to select the required material in such a manner that it will be suitable for the operating temperature and not lower. The most economical materials for low temperatures are steels. Ordinary carbon steel can be used down to -20$F and the Killed carbon steel down to -50$F. Nickel steels (2 1/4%) can be used down to -75$ to 100$F, Nickel steels (3 1/2%) down to -150$F, and 9% nickel steels down to 1,320$F. Stainless and aluminum alloys can be used down to -423$F. Tabular data give some commonly used materials in low temperature and cryogenic services with their lowest allowable temperature, tensile strength, and relative cost.

  14. Failure mechanism dependence and reliability evaluation of non-repairable system

    International Nuclear Information System (INIS)

    Chen, Ying; Yang, Liu; Ye, Cui; Kang, Rui

    2015-01-01

    Reliability study of electronic system with the physics-of-failure method has been promoted due to the increase knowledge of electronic failure mechanisms. System failure initiates from independent failure mechanisms, have effect on or affect by other failure mechanisms and finally result in system failure. Failure mechanisms in a non-repairable system have many kinds of correlation. One failure mechanism developing to a certain degree will trigger, accelerate or inhibit another or many other failure mechanisms, some kind of failure mechanisms may have the same effect on the failure site, component or system. The destructive effect will be accumulated and result in early failure. This paper presents a reliability evaluation method considering correlativity among failure mechanisms, which includes trigger, acceleration, inhibition, accumulation, and competition. Based on fundamental rule of physics of failure, decoupling methods of these correlations are discussed. With a case, reliability of electronic system is evaluated considering failure mechanism dependence. - Highlights: • Five types of failure mechanism correlations are described. • Decoupling methods of these correlations are discussed. • A reliability evaluation method considering mechanism dependence is proposed. • Results are quite different to results under failure independence assumption

  15. Reliability Analysis of a Cold Standby System with Imperfect Repair and under Poisson Shocks

    Directory of Open Access Journals (Sweden)

    Yutian Chen

    2014-01-01

    Full Text Available This paper considers the reliability analysis of a two-component cold standby system with a repairman who may have vacation. The system may fail due to intrinsic factors like aging or deteriorating, or external factors such as Poisson shocks. The arrival time of the shocks follows a Poisson process with the intensity λ>0. Whenever the magnitude of a shock is larger than the prespecified threshold of the operating component, the operating component will fail. The paper assumes that the intrinsic lifetime and the repair time on the component are an extended Poisson process, the magnitude of the shock and the threshold of the operating component are nonnegative random variables, and the vacation time of the repairman obeys the general continuous probability distribution. By using the vector Markov process theory, the supplementary variable method, Laplace transform, and Tauberian theory, the paper derives a number of reliability indices: system availability, system reliability, the rate of occurrence of the system failure, and the mean time to the first failure of the system. Finally, a numerical example is given to validate the derived indices.

  16. Propagated failure analysis for non-repairable systems considering both global and selective effects

    International Nuclear Information System (INIS)

    Wang Chaonan; Xing Liudong; Levitin, Gregory

    2012-01-01

    This paper proposes an algorithm for the reliability analysis of non-repairable binary systems subject to competing failure propagation and failure isolation events with both global and selective failure effects. A propagated failure that originates from a system component causes extensive damage to the rest of the system. Global effect happens when the propagated failure causes the entire system to fail; whereas selective effect happens when the propagated failure causes only failure of a subset of system components. In both cases, the failure propagation that originates from some system components (referred to as dependent components) can be isolated because of functional dependence between the dependent components and a component that prevents the failure propagation (trigger components) when the failure of the trigger component happens before the occurrence of the propagated failure. Most existing studies focus on the analysis of propagated failures with global effect. However, in many cases, propagated failures affect only a subset of system components not the entire system. Existing approaches for analyzing propagated failures with selective effect are limited to series-parallel systems. This paper proposes a combinatorial method for the propagated failure analysis considering both global and selective effects as well as the competition with the failure isolation in the time domain. The proposed method is not limited to series-parallel systems and has no limitation on the type of time-to-failure distributions for the system components. The method is verified using the Markov-based method. An example of computer memory systems is analyzed to demonstrate the application of the proposed method.

  17. Test System for Thermoelectric Modules and Materials

    Science.gov (United States)

    Hejtmánek, J.; Knížek, K.; Švejda, V.; Horna, P.; Sikora, M.

    2014-10-01

    We present a design for a complex measuring device that enables its user to assess the parameters of power-generating thermoelectric modules (TEMs) (or bulk thermoelectric materials) under a wide range of temperatures ( T cold = 25°C to 90°C, T hot TEM, the actual heat flow through the module, and its mechanical load, which can be varied during the measurement. Key components of our testing setup are (i) a measuring chamber where the TEM/material is compressed between thermally shielded heating blocks equipped with a mechanical loading system and water-cooled copper-based cooler, (ii) an electrical load system, (iii) a type K thermocouple array connected to a data acquisition computer, and (iv) a thermostatic water-based cooling system with electronically controlled flow rate and temperature of cooling water. Our testing setup represents a useful tool able to assess, e.g., the thermoelectric parameters of newly developed TEMs and materials or to evaluate the thermoelectric parameters of commercially available modules and materials for comparison with values declared by the manufacturer.

  18. The on-line repair, improvement and expansion of a working multicomputer control system for the CERN SPS accelerator

    International Nuclear Information System (INIS)

    Altaber, J.; Beck, F.; Collins, M.; Crowley-Milling, M.C.; Rausch, R.

    1979-01-01

    The 400 GeV proton synchrotron at CERN was first commissioned in 1976. Those of its features which are pertinent to the design of the control system are summarized. The paper then proceeds as follows: changes to the control system (changes to applications programs, equipment handling routines, system software changes); hardware increases and repairs; changes to the character of the system (hardware changes, microprocessors); conclusions. (U.K.)

  19. Repairing rabbit radial defects by combining bone marrow stroma stem cells with bone scaffold material comprising a core-cladding structure.

    Science.gov (United States)

    Wu, H; Liu, G H; Wu, Q; Yu, B

    2015-10-05

    We prepared a bone scaffold material comprising a PLGA/β-TCP core and a Type I collagen cladding, and recombined it with bone marrow stroma stem cells (BMSCs) to evaluate its potential for use in bone tissue engineering by in vivo and in vitro experiments. PLGA/β-TCP without a cladding was used for comparison. The adherence rate of the BMSCs to the scaffold was determined by cell counting. Cell proliferation rate was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. The osteogenic capability was evaluated by alkaline phosphatase activity. The scaffold materials were recombined with the BMSCs and implanted into a large segmental rabbit radial defect model to evaluate defect repair. Osteogenesis was assessed in the scaffold materials by histological and double immunofluorescence labeling, etc. The adherence number, proliferation number, and alkaline phosphatase expression of the cells on the bone scaffold material with core-cladding structure were significantly higher than the corresponding values in the PLGA/β-TCP composite scaffold material (P structure completely degraded at the bone defect site and bone formation was completed. The rabbit large sentimental radial defect was successfully repaired. The degradation and osteogenesis rates matched well. The bone scaffold with core-cladding structure exhibited better osteogenic activity and capacity to repair a large segmental bone defect compared to the PLGA/β-TCP composite scaffold. The bone scaffold with core-cladding structure has excellent physical properties and biocompatibility. It is an ideal scaffold material for bone tissue engineering.

  20. In vitro Repair of Oxidative DNA Damage by Human Nucleotide Excision Repair System: Possible Explanation for Neurodegeneration in Xeroderma Pigmentosum Patients

    Science.gov (United States)

    Reardon, Joyce T.; Bessho, Tadayoshi; Kung, Hsiang Chuan; Bolton, Philip H.; Sancar, Aziz

    1997-08-01

    Xeroderma pigmentosum (XP) patients fail to remove pyrimidine dimers caused by sunlight and, as a consequence, develop multiple cancers in areas exposed to light. The second most common sign, present in 20-30% of XP patients, is a set of neurological abnormalities caused by neuronal death in the central and peripheral nervous systems. Neural tissue is shielded from sunlight-induced DNA damage, so the cause of neurodegeneration in XP patients remains unexplained. In this study, we show that two major oxidative DNA lesions, 8-oxoguanine and thymine glycol, are excised from DNA in vitro by the same enzyme system responsible for removing pyrimidine dimers and other bulky DNA adducts. Our results suggest that XP neurological disease may be caused by defective repair of lesions that are produced in nerve cells by reactive oxygen species generated as by-products of an active oxidative metabolism.

  1. Materials handbook for fusion energy systems

    International Nuclear Information System (INIS)

    Davis, J.W.

    1988-01-01

    The objective of this work is to provide a consistent and authoritative source of material property data for use by the fusion community in concept evaluation, design, and performance/verification studies of the various fusion energy systems. A second objective is the early identification of areas in the materials data base where insufficient information or voids exist. The effort during this reporting period has focused on two areas: (1) publication of data pages, and (2) automation of the data pages. The data pages contained new engineering information on lithium and stainless steel along with additional Supporting Documentation pages on annealed and cold worked stainless steel. These pages were distributed in May. In the area of automation, work is proceeding on schedule toward the formation of an electronic materials data base for the MFE computer network

  2. Automatized system of radioactive material analysis

    International Nuclear Information System (INIS)

    Pchelkin, V.A.; Sviderskij, M.F.; Litvinov, V.A.; Lavrikov, S.A.

    1979-01-01

    An automatized system has been developed for the identification of substance, element and isotope content of radioactive materials on the basis of data obtained for studying physical-chemical properties of substances (with the help of atomic-absorption spectrometers, infrared spectrometer, mass-spectrometer, derivatograph etc.). The system is based on the following principles: independent operation of each device; a possibility of increasing the number of physical instruments and devices; modular properties of engineering and computer means; modular properties and standardization of mathematical equipment, high reliability of the system; continuity of programming languages; a possibility of controlling the devices with the help of high-level language, typification of the system; simple and easy service; low cost. Block-diagram of the system is given

  3. Real-Time Multifault Rush Repairing Strategy Based on Utility Theory and Multiagent System in Distribution Networks

    Directory of Open Access Journals (Sweden)

    Zhao Hao

    2016-01-01

    Full Text Available The problem of multifault rush repair in distribution networks (DNs is a multiobjective dynamic combinatorial problem with topology constraints. The problem consists of archiving an optimal faults’ allocation strategy to squads and an admissible multifault rush repairing strategy with coordinating switch operations. In this article, the utility theory is introduced to solve the first problem and a new discrete bacterial colony chemotaxis (DBCC algorithm is proposed for the second problem to determine the optimal sequence for each squad to repair faults and the corresponding switch operations. The above solution is called the two-stage approach. Additionally, a double mathematical optimization model based on the fault level is proposed in the second stage to minimize the outage loss and total repairing time. The real-time adjustment multiagent system (RA-MAS is proposed to provide facility to achieve online multifault rush repairing strategy in DNs when there are emergencies after natural disasters. The two-stage approach is illustrated with an example from a real urban distribution network and the simulation results show the effectiveness of the two-stage approach.

  4. Materials and fabrication requirements for APWR systems

    International Nuclear Information System (INIS)

    Boothby, R.M.; Hippsley, C.A.; Gorton, O.K.; Garwood, S.J.

    1995-01-01

    Materials specifications for advanced pressurized water-cooled reactor (APWR) systems are generally based on existing designs, with improved materials and fabrication procedures being developed to counter known degradation effects. In this paper, materials ageing and degradation mechanisms in PWR primary circuit pressure boundary components (i.e. the reactor pressure vessel (RPV), control rod drive mechanisms (CRDMs), coolant piping, coolant pump casing, pressurizer, and steam generators) are reviewed. Important degradation mechanisms include irradiation embrittlement of the RPV, thermal ageing embrittlement of ferritic (e.g. the pressurizer) and cast austenitic (e.g. coolant pump casing and pipe elbows) steel components and environmentally assisted cracking of steam generator tubing and CRDM penetrations. Improved materials specifications and component design and fabrication issues affecting the integrity of the pressure boundary are discussed in the light of these materials problems. Improved fabrication procedures adopted for Sizewell B, such as the utilization of ring forgings to eliminate axial welds in the RPV and steam generator shells and the use of one-piece castings for coolant pump casings, provide a benchmark against which other APWR designs may be judged. (author)

  5. Composite repairs qualification according to ISO/TS 24817

    Energy Technology Data Exchange (ETDEWEB)

    Meniconi, Luiz C.M.; Perrut, Valber A. [Petroleo Brasileiro S.A. (PETROBRAS/CENPES), Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2009-07-01

    Composite repairs for metallic pipes from three different suppliers were evaluated according to ISO Technical Specification TS 24817. The intended application scenarios are offshore production plants, but the design methodology is also applicable to onshore pipelines and pipework. The evaluation covered all the relevant mechanical properties and established the maximum application temperatures for each repair system. The tests also considered the application of composite repair sleeves to metallic pipes with through thickness defects, by measuring the strain energy release rates of the composite-metal interfaces. The test campaigns aimed to verify the applicability of the recently published ISO document, and to implement it as the routine procedure for composite repairs evaluation within PETROBRAS. The tests also addressed the influence of metallic pipe surface preparation on the final properties of the repair sleeves, especially in relation to the long term behavior of leaking pipes repaired by means of composite materials. (author)

  6. On the interaction between maintenance, spare part inventories and repair capacity for a k-out-of-N-system with wear-out

    NARCIS (Netherlands)

    de Smidt-Destombes, Karin S.; van der Heijden, Matthijs C.; van Harten, Aart

    2006-01-01

    In this paper we consider a k-out-of-N system with identical, repairable components under a condition-based maintenance policy. Maintenance consists of replacing all failed and/or aged components. Next, the replaced components have to be repaired. The system availability can be controlled by the

  7. On the interaction between maintenance, spare part inventories and repair capacity for a k-out-of-N system with wear-out

    NARCIS (Netherlands)

    Smidt-Destombes, K.S. de; Heijden, M.C. van der; Harten, A. van

    2006-01-01

    In this paper we consider a k-out-of-N system with identical, repairable components under a condition-based maintenance policy. Maintenance consists of replacing all failed and/or aged components. Next, the replaced components have to be repaired. The system availability can be controlled by the

  8. Development of biodegradable polycaprolactone film as an internal fixation material to enhance tendon repair: an in vitro study.

    Science.gov (United States)

    Hu, Jian-Zhong; Zhou, Yong-Chun; Huang, Li-Hua; Lu, Hong-Bin

    2013-08-19

    Current tendon repair techniques do not provide sufficient tensile strength at the repair site, and thus early active motion rehabilitation after tendon repair is discouraged. To enhance the post-operative tensile strength, we proposed and tested an internal fixation technique using a polycaprolactone (PCL) biofilm. PCL was chosen for its good biocompatibility, excellent mechanical strength, and an appropriate degradation time scale. PCL biofilms were prepared by a modified melt-molding/leaching technique, and the physical and mechanical properties and in vitro degradation rate were assessed. The pore size distribution of the biofilm and the paratenon of native tendons were observed using scanning electron microscopy. Next, we determined whether this biofilm could enhance the tensile strength of repaired tendons. We performed tensile tests on rabbit Achilles tendons that were first lacerated and then repaired: 1) using modified Kessler suture combined with running peripheral suture ('control' group), or 2) using biofilm to wrap the tendon and then fixation with sutures ('biofilm' group). The influence of different repair techniques on tendon tensile strength was evaluated by mechanical testing. The novel biofilm had supple texture and a smooth surface. The mean thickness of the biofilm was 0.25 mm. The mean porosity of the biofilm was 45.3%. The paratenon of the rabbit Achilles tendon had pores with diameters ranging from 1 to 9 μm, which were similar to the 4-12 μm diameter pores in the biofilm cross-section. The weight loss of the biofilms at 4 weeks was only 0.07%. The molecular weight of PCL biofilms did not change after immersion in phosphate buffered saline for 4 weeks. The failure loads of the biofilm were similar before (48 ± 9 N) and after immersion (47 ± 7 N, P > 0.1). The biofilm group had ~70% higher mean failure loads and 93% higher stiffness compared with the control group. We proposed and tested an internal fixation technique

  9. Participatory Design Research as a Practice for Systemic Repair: Doing Hand-in-Hand Math Research with Families

    Science.gov (United States)

    Booker, Angela; Goldman, Shelley

    2016-01-01

    Success and failure in formal mathematics education has been used to legitimize stratification. We describe participatory design research as a methodology for systemic repair. The analysis describes epistemic authority--exercising the right or the power to know--as a form of agency in processes of mathematical problem solving and learning. We…

  10. Early passage bone marrow stromal cells express genes involved in nervous system development supporting their relevance for neural repair

    NARCIS (Netherlands)

    Nandoe Tewarie, R.D.S.; Bossers, K.; Ritfeld, G.J.; Blits, B.; Grotenhuis, J.A.; Verhaagen, J.; Oudega, M.

    2011-01-01

    PURPOSE: The assessment of the capacity of bone marrow stromal cells (BMSC) to repair the nervous system using gene expression profiling. The evaluation of effects of long-term culturing on the gene expression profile of BMSC. METHODS: Fourty four k whole genome rat microarrays were used to study

  11. FACADE SYSTEM MADE OF POROUS MATERIALS

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2012-10-01

    Full Text Available The proposed multi-component façade system is made of porous concretes employed both as bearing structures and for heat insulation and fireproofing purposes. The authors also provide their recommendations in respect of the mounting of the proposed façade system. The façade system considered in the article is composed of wall foam concrete blocks reinforced by basalt fibers (bearing elements of the structure, cellular concrete polystyrene (thermal insulation, and porous concrete (fireproofing and thermal insulation. Retained shuttering (in the fireproofing sections represents chrysolite cement sheets attached to the structures composed of glass-fiber plastic elements. The application of insulating porous concrete as a fireproofing material is based on the principle of adjustable stress-strained states of materials in the environment of variable pressure. This technology was developed at Moscow State University of Civil Engineering, and it was initially designated for the manufacturing of tailor-made products. The above concrete is also designated for retained shuttering and modified cavity masonry walls. Porous concrete that expands inside the fireproofing cavity ensures a tight contact both with the basic material and thermal insulation plates. The use of materials of the same origin (Portland cement means the formation of strong transition zones connecting the system components in the course of its hardening and further operation. The results of the thermotechnical calculation demonstrate that the thermal resistance registered on the surface of the wall that is 3 meters high (that has a 0.4 m fireproofing cavity is equal to 3.98 sq. m. C/Wt. The value of the coefficient of thermotechnical heterogeneity (r is equal to 0.86 with account for the thickness and thermal conductivity of point and linear elements. If the thermotechnical heterogeneity is taken into consideration, the thermal resistance of the proposed wall is equal to 3.42 m2 С/Wt.

  12. MULTI-AGENT APPROACH TO BUILDING AN INTELLIGENT VEHICLE MAINTENANCE AND REPAIR SYSTEM

    Directory of Open Access Journals (Sweden)

    V. Pavlenko

    2017-12-01

    Full Text Available To ensure the reliability of the car, early detection and prevention of the occurrence and development of failures is required in order to reduce the costs of maintenance and repair. Multi-agent technologies make it possible to raise the level of technical reliability of cars and minimize the costs of performing repair and maintenance operations.

  13. Nuclear data information system for nuclear materials

    International Nuclear Information System (INIS)

    Fujita, Mitsutane; Noda, Tetsuji; Utsumi, Misako

    1996-01-01

    The conceptual system for nuclear material design is considered and some trials on WWW server with functions of the easily accessible simulation of nuclear reactions are introduced. Moreover, as an example of the simulation on the system using nuclear data, transmutation calculation was made for candidate first wall materials such as 9Cr-2W steel, V-5Cr-5Ti and SiC in SUS316/Li 2 O/H 2 O(SUS), 9Cr-2W/Li 2 O/H 2 O(RAF), V alloy/Li/Be(V), and SiC/Li 2 ZrO 3 /He(SiC) blanket/shield systems based on ITER design model. Neutron spectrum varies with different blanket/shield compositions. The flux of low energy neutrons decreases in order of V< SiC< RAF< SUS blanket/shield systems. Fair amounts of W depletion in 9Cr-2W steel and the increase of Cr content in V-5Cr-5Ti were predicted in SUS or RAF systems. Concentration change in W and Cr is estimated to be suppressed if Li coolant is used in place of water. Helium and hydrogen production are not strongly affected by the different blanket/shield compositions. (author)

  14. Developing Higher-Order Materials Knowledge Systems

    Science.gov (United States)

    Fast, Anthony Nathan

    2011-12-01

    Advances in computational materials science and novel characterization techniques have allowed scientists to probe deeply into a diverse range of materials phenomena. These activities are producing enormous amounts of information regarding the roles of various hierarchical material features in the overall performance characteristics displayed by the material. Connecting the hierarchical information over disparate domains is at the crux of multiscale modeling. The inherent challenge of performing multiscale simulations is developing scale bridging relationships to couple material information between well separated length scales. Much progress has been made in the development of homogenization relationships which replace heterogeneous material features with effective homogenous descriptions. These relationships facilitate the flow of information from lower length scales to higher length scales. Meanwhile, most localization relationships that link the information from a from a higher length scale to a lower length scale are plagued by computationally intensive techniques which are not readily integrated into multiscale simulations. The challenge of executing fully coupled multiscale simulations is augmented by the need to incorporate the evolution of the material structure that may occur under conditions such as material processing. To address these challenges with multiscale simulation, a novel framework called the Materials Knowledge System (MKS) has been developed. This methodology efficiently extracts, stores, and recalls microstructure-property-processing localization relationships. This approach is built on the statistical continuum theories developed by Kroner that express the localization of the response field at the microscale using a series of highly complex convolution integrals, which have historically been evaluated analytically. The MKS approach dramatically improves the accuracy of these expressions by calibrating the convolution kernels in these

  15. Multipurpose expert-robot system model for control, diagnosis, maintenance, and repairs at the steam generators of the NPP

    International Nuclear Information System (INIS)

    Popa, I.

    1994-01-01

    The paper presents the model concept for a multipurpose expert-robot system for control, diagnosis, forecast, maintenance, and repairs at the steam generators of CANDU type nuclear power plants. The system has two separate parts: the expert system and the robot (manipulator) system. These parts compose a hierarchic structure with the expert system on the upper level. The expert system has a blackboard architecture, to which tree interfaces with the robot system, with the control system of the NPP and with the methods and techniques of control, maintenance and repairs system of the steam generator are added. Due to complex nature of its activities the expert-robot system model combines the deterministic type reasons with probabilistic, fuzzy, and neural-networks type ones. The information that enter the expert system comes from the robot system, from process, from user, and human expert. The information that enter robot system comes from the expert system, from the human operator (when connected) and from process. Control maintenance and repair operations take place by means of the robot system that can be monitored either directly by the expert system or by the human operator who follows its activity. All these activities are performed in parallel with the adequate information of the expert system directly, by the human operator, about the status parameters and, possibly, operating parameters of the steam generator components. The expert-robot system can work independently, but it can be connected and integrated in the control system of NPP, to take over and develop some of its functions. The activities concerning diagnosis and characterization of the state of steam generator components subsequent to control, as well as the forecast of their future behavior, are performed by means of the expert system. Due to these characteristics the expert-robot system can be used successfully in personnel training activities. (Author)

  16. Model System for Live Imaging of Neuronal Responses to Injury and Repair

    Directory of Open Access Journals (Sweden)

    Mathieu Gravel

    2011-11-01

    Full Text Available Although it has been well established that induction of growth-associated protein-43 (GAP-43 during development coincides with axonal outgrowth and early synapse formation, the existence of neuronal plasticity and neurite outgrowth in the adult central nervous system after injuries is more controversial. To visualize the processes of neuronal injury and repair in living animals, we generated reporter mice for bioluminescence and fluorescence imaging bearing the luc (luciferase and gfp (green fluorescent protein reporter genes under the control of the murine GAP-43 promoter. Reporter functionality was first observed during the development of transgenic embryos. Using in vivo bioluminescence and fluorescence imaging, we visualized induction of the GAP-43 signals from live embryos starting at E10.5, as well as neuronal responses to brain and peripheral nerve injuries (the signals peaked at 14 days postinjury. Moreover, three-dimensional analysis of the GAP-43 bioluminescent signal confirmed that it originated from brain structures affected by ischemic injury. The analysis of fluorescence signal at cellular level revealed colocalization between endogenous protein and the GAP-43-driven gfp transgene. Taken together, our results suggest that the GAP-43-luc/gfp reporter mouse represents a valid model system for real-time analysis of neurite outgrowth and the capacity of the adult nervous system to regenerate after injuries.

  17. Single-Molecule Methods for Nucleotide Excision Repair: Building a System to Watch Repair in Real Time

    OpenAIRE

    Kong, Muwen; Beckwitt, Emily C.; Springall, Luke; Kad, Neil M.; Van Houten, Bennett

    2017-01-01

    Single-molecule approaches to solving biophysical problems are powerful tools that allow static and dynamic real-time observations of specific molecular interactions of interest in the absence of ensemble-averaging effects. Here, we provide detailed protocols for building an experimental system that employs atomic force microscopy and a single-molecule DNA tightrope assay based on oblique angle illumination fluorescence microscopy. Together with approaches for engineering site-specific lesion...

  18. Target system materials and engineering problems

    International Nuclear Information System (INIS)

    Fischer, W.E.

    1989-01-01

    This paper discusses the common problems of target design. As a model for the discussion, the author considers a spallation source which is fed by a high power proton beam of the order of one megawatt. The materials used for the target station and particularly for the spallation target itself depend on whether the source is built for pulsed, modulated or continuous operation. The difference of materials used is mainly determined by the neutronics considerations. Depending on the choice of materials for the target systems, the characters of material problems met, are of somewhat different nature. It is recognized that for each target version quite specific difficulties have to be overcome. On the other hand, there is a whole set of problems which is common to all target versions. These are: heat load in region of proton beam interactions; thermal stress and cycling; and radiation damage. It is shown that solutions to the whole package of problems up to a beam power of 0 (1MW) have been found. The whole effort concentrates onto the region of the first few centimeters of beam penetration. Two solutions have been proposed: (1) Keep the power of proton beam limited and produce neutrons elsewhere in the target. and (2) Dilute the power by moving mechanically the target and the window. 8 refs., 11 figs

  19. Optoelectronic inventory system for special nuclear material

    International Nuclear Information System (INIS)

    Sieradzki, F.H.

    1994-01-01

    In support of the Department of Energy's Dismantlement Program, the Optoelectronics Characterization and Sensor Development Department 2231 at Sandia National Laboratories/New Mexico has developed an in situ nonintrusive Optoelectronic Inventory System (OIS) that has the potential for application wherever periodic inventory of selected material is desired. Using a network of fiber-optic links, the OIS retrieves and stores inventory signatures from data storage devices (which are permanently attached to material storage containers) while inherently providing electromagnetic pulse immunity and electrical noise isolation. Photovoltaic cells (located within the storage facility) convert laser diode optic power from a laser driver to electrical energy. When powered and triggered, the data storage devices sequentially output their digital inventory signatures through light-emitting diode/photo diode data links for retrieval and storage in a mobile data acquisition system. An item's exact location is determined through fiber-optic network and software design. The OIS provides an on-demand method for obtaining acceptable inventory reports while eliminating the need for human presence inside the material storage facility. By using modularization and prefabricated construction with mature technologies and components, an OIS installation with virtually unlimited capacity can be tailored to the customer's requirements

  20. Radiographic and histological study of perennial bone defect repair in rat calvaria after treatment with blocks of porous bovine organic graft material.

    Science.gov (United States)

    Marins, Lucele Vieira; Cestari, Tania Mary; Sottovia, André Dotto; Granjeiro, José Mauro; Taga, Rumio

    2004-03-01

    Over the last few years, various bone graft materials of bovine origin to be used in oromaxillofacial surgeries have entered the market. In the present study, we determined the capacity of a block organic bone graft material (Gen-ox, Baumer SA, Brazil) prepared from bovine cancellous bone to promote the repair of critical size bone injuries in rat calvaria. A transosseous defect measuring approximately 8mm in diameter was performed with a surgical trephine in the parietal bone of 25 rats. In 15 animals, the defects were filled with a block of graft material measuring 8mm in diameter and soaked in the animal's own blood, and in the other 10 animals the defects were only filled with blood clots. The calvariae of rats receiving the material were collected 1, 3 and 6 months after surgery, and those of animals receiving the blood clots were collected immediately and 6 months after surgery. During surgery, the graft material was found to be of easy handling and to adapt perfectly to the receptor bed after soaking in blood. The results showed that, in most animals treated, the material was slowly resorbed and served as a space filling and maintenance material, favoring angiogenesis, cell migration and adhesion, and bone neoformation from the borders of the lesion. However, a foreign body-type granulomatous reaction, with the presence of numerous giant cells preventing local bone neoformation, was observed in two animals of the 1-month subgroup and in one animal of the 3-month subgroup. These cases were interpreted as resulting from the absence of demineralization and the lack of removal of potential antigen factors during production of the biomaterial. We conclude that, with improvement in the quality control of the material production, block organic bone matrix will become a good alternative for bone defect repair in the oromaxillofacial region due to its high osteoconductive capacity.

  1. Materials accounting system for an IBM PC

    International Nuclear Information System (INIS)

    Bearse, R.C.; Thomas, R.J.; Henslee, S.P.; Jackson, B.G.; Tracy, D.B.; Pace, D.M.

    1986-01-01

    We have adapted the Los Alamos MASS accounting system for use on an IBM PC/AT at the Fuels Manufacturing Facility (FMF) at Argonne National Laboratory-West (ANL-WEST) in Idaho Falls, Idaho. Cost of hardware and proprietary software was less than $10,000 per station. The system consists of three stations between which accounting information is transferred using floppy disks accompanying special nuclear material shipments. The programs were implemented in dBASEIII and were compiled using the proprietary software CLIPPER. Modifications to the inventory can be posted in just a few minutes, and operator/computer interaction is nearly instantaneous. After the records are built by the user, it takes 4 to 5 seconds to post the results to the database files. A version of this system was specially adapted and is currently in use at the FMF facility at Argonne National Laboratory in Idaho Falls. Initial satisfaction is adequate and software and hardware problems are minimal

  2. Electrochemical and materials aspects of tribocorrosion systems

    International Nuclear Information System (INIS)

    Landolt, D

    2006-01-01

    Tribocorrosion involves mechanical and chemical/electrochemical interactions between surfaces in relative motion in the presence of a corrosive environment. Tribocorrosion phenomena are encountered in many technological areas where they cause damage to installations, machines and devices. Often tribocorrosion damage is a problem for safety or for human health. In other applications tribocorrosion phenomena are put to good use in manufacturing. The chemo-mechanical mechanisms of tribocorrosion are still incompletely understood, they involve the properties of contacting material surfaces, the mechanics of the contact and the corrosion conditions. Electrochemical methods are widely used for the study of tribocorrosion reactions. To yield information about synergistic and antagonistic mechanisms they must be applied in situ under strictly controlled mechanical conditions, using materials with well-characterized surface properties. Recent progress in modelling and understanding of tribocorrosion systems is discussed and some challenges and opportunities for future research are identified

  3. The zebrafish as a gerontology model in nervous system aging, disease, and repair.

    Science.gov (United States)

    Van Houcke, Jessie; De Groef, Lies; Dekeyster, Eline; Moons, Lieve

    2015-11-01

    Considering the increasing number of elderly in the world's population today, developing effective treatments for age-related pathologies is one of the biggest challenges in modern medical research. Age-related neurodegeneration, in particular, significantly impacts important sensory, motor, and cognitive functions, seriously constraining life quality of many patients. Although our understanding of the causal mechanisms of aging has greatly improved in recent years, animal model systems still have much to tell us about this complex process. Zebrafish (Danio rerio) have gained enormous popularity for this research topic over the past decade, since their life span is relatively short but, like humans, they are still subject to gradual aging. In addition, the extensive characterization of its well-conserved molecular and cellular physiology makes the zebrafish an excellent model to unravel the underlying mechanisms of aging, disease, and repair. This review provides a comprehensive overview of the progress made in zebrafish gerontology, with special emphasis on nervous system aging. We review the evidence that classic hallmarks of aging can also be recognized within this small vertebrate, both at the molecular and cellular level. Moreover, we illustrate the high level of similarity with age-associated human pathologies through a survey of the functional deficits that arise as zebrafish age. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Genetic defects in DNA repair system and enhancement of intergenote transformation efficiency in Bacillus subtilis Marburg

    International Nuclear Information System (INIS)

    Matsumoto, K.; Takahashi, H.; Saito, H.; Ikeda, Y.

    1978-01-01

    Mechanisms of inefficiency in heterospecies transformation were studied with a transformation system consisting of Bacillus subtilis 168TI (trpC2thy) as recipient and of DNA prepared from partially hybrid strains of B. subtilis which had incorporated trp + DNA of B. amyloliquefaciens 203 (formerly, B. megaterium 203) in the chromosome (termed intergenote). The intergenote transformation was not so efficient as the corresponding homospecies transformation and the efficiency appeared to relate inversely with the length of heterologous portion in the intergenote. When a variety of ultraviolet light (UV) sensitive mutants, deficient in host-cell reactivation capacity, were used as recipients for the intergenote transformation, 2 out of 16 mutants exhibited significantly enhanced transformation efficiency of the trpC marker. Genetic studies by transformation showed that the trait relating to the enhancement of intergenote-transformation efficiency was always associated with the UV sensitivity, suggesting that these two traits are determined by a single gene. The efficiency of intergenote transformation was highly affected also by DNA concentration; the lower the concentration, the less the efficiency. When, however, the UV sensitive mutant was used as recipient, the effect of DNA concentration was largely diminished, suggesting the reduction of DNA-inactivating activity in the UV sensitive recipient. These results were discussed in relation to a possible excision-repair system selectively correcting the mismatched DNA in the course of intergenote transformation. (orig.) [de

  5. Evolution and adaptation in Pseudomonas aeruginosa biofilms driven by mismatch repair system-deficient mutators.

    Directory of Open Access Journals (Sweden)

    Adela M Luján

    Full Text Available Pseudomonas aeruginosa is an important opportunistic pathogen causing chronic airway infections, especially in cystic fibrosis (CF patients. The majority of the CF patients acquire P. aeruginosa during early childhood, and most of them develop chronic infections resulting in severe lung disease, which are rarely eradicated despite intensive antibiotic therapy. Current knowledge indicates that three major adaptive strategies, biofilm development, phenotypic diversification, and mutator phenotypes [driven by a defective mismatch repair system (MRS], play important roles in P. aeruginosa chronic infections, but the relationship between these strategies is still poorly understood. We have used the flow-cell biofilm model system to investigate the impact of the mutS associated mutator phenotype on development, dynamics, diversification and adaptation of P. aeruginosa biofilms. Through competition experiments we demonstrate for the first time that P. aeruginosa MRS-deficient mutators had enhanced adaptability over wild-type strains when grown in structured biofilms but not as planktonic cells. This advantage was associated with enhanced micro-colony development and increased rates of phenotypic diversification, evidenced by biofilm architecture features and by a wider range and proportion of morphotypic colony variants, respectively. Additionally, morphotypic variants generated in mutator biofilms showed increased competitiveness, providing further evidence for mutator-driven adaptive evolution in the biofilm mode of growth. This work helps to understand the basis for the specific high proportion and role of mutators in chronic infections, where P. aeruginosa develops in biofilm communities.

  6. NAXE Mutations Disrupt the Cellular NAD(P)HX Repair System and Cause a Lethal Neurometabolic Disorder of Early Childhood.

    Science.gov (United States)

    Kremer, Laura S; Danhauser, Katharina; Herebian, Diran; Petkovic Ramadža, Danijela; Piekutowska-Abramczuk, Dorota; Seibt, Annette; Müller-Felber, Wolfgang; Haack, Tobias B; Płoski, Rafał; Lohmeier, Klaus; Schneider, Dominik; Klee, Dirk; Rokicki, Dariusz; Mayatepek, Ertan; Strom, Tim M; Meitinger, Thomas; Klopstock, Thomas; Pronicka, Ewa; Mayr, Johannes A; Baric, Ivo; Distelmaier, Felix; Prokisch, Holger

    2016-10-06

    To safeguard the cell from the accumulation of potentially harmful metabolic intermediates, specific repair mechanisms have evolved. APOA1BP, now renamed NAXE, encodes an epimerase essential in the cellular metabolite repair for NADHX and NADPHX. The enzyme catalyzes the epimerization of NAD(P)HX, thereby avoiding the accumulation of toxic metabolites. The clinical importance of the NAD(P)HX repair system has been unknown. Exome sequencing revealed pathogenic biallelic mutations in NAXE in children from four families with (sub-) acute-onset ataxia, cerebellar edema, spinal myelopathy, and skin lesions. Lactate was elevated in cerebrospinal fluid of all affected individuals. Disease onset was during the second year of life and clinical signs as well as episodes of deterioration were triggered by febrile infections. Disease course was rapidly progressive, leading to coma, global brain atrophy, and finally to death in all affected individuals. NAXE levels were undetectable in fibroblasts from affected individuals of two families. In these fibroblasts we measured highly elevated concentrations of the toxic metabolite cyclic-NADHX, confirming a deficiency of the mitochondrial NAD(P)HX repair system. Finally, NAD or nicotinic acid (vitamin B3) supplementation might have therapeutic implications for this fatal disorder. Copyright © 2016 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  7. Nanostructural Materials for Energy Storage Systems

    Directory of Open Access Journals (Sweden)

    Bronislaw Buczek

    2011-01-01

    Full Text Available The aim of this study was to assess of carbonaceous monoliths used for adsorption cooling systems. The carbonaceous monoliths prepared from coal precursors are obtained. The porous structure of monoliths was evaluated on the basis of nitrogen adsorption-desorption data. The investigated monoliths have significantly developed microporous structure. The large specific area of carbonaceous monoliths (about 2000 m2/g and volume of micropores are observed. Methanol adsorption isotherms and heat of wetting using methanol was determined. Results show that monoliths materials are high adsorption capacity of methanol and heat of wetting, which can improve of heat exchange and efficiency in processes of refrigeration and air conditioning.

  8. Application of a System-Based Inventory Model to Marine Corps Repairable Parts

    National Research Council Canada - National Science Library

    Barnett, Craig

    2001-01-01

    ... isolation of the inventories and because of mathematical flaws in the Marine Corps' sparing methodology The Marine Corps is seeking to centralize the management of secondary repairables and is considering...

  9. Economic Analysis for Setting Appropriate Repair Cycles on the Fixed Materials and Facilities in the Public Rental Housing

    Directory of Open Access Journals (Sweden)

    Sung-Min Choi

    2016-01-01

    Full Text Available Currently, repair and maintenance cycles that follow the completion of construction facilities lead to the necessitation of subsequent data on the analysis of study and plan for maintenance. As such, an index of evaluation was drafted and a plan of maintenance cycle was computed using the investigation data derived from surveying target housing units in permanent rental environmental conditions, with a minimum age of 20 years, and their maintenance history. Optimal maintenance and replacement methods were proposed based on this data. Economic analysis was conducted through the Risk-Weighted Life Cycle Cost (RWLCC method in order to determine the cost analysis of maintenance life cycle methods used for repair. Current maintenance cycle methods that have been used for 20 years were also compared with alternative maintenance cycles.

  10. The effect of caffeine on repair systems in oocytes of Drosophila melanogaster

    International Nuclear Information System (INIS)

    Mendelson, D.

    1976-01-01

    Genetic analysis was performed to locate the factors involved in the defective repair mechanism in the oocytes of Ubx e 4 /Payne ca females. The results demonstrate that at least three third-chromosome factors may be involved in the control of maternal repair, the two most effective ones being located on the right arm of the third chromosome, one near the Ubx locus and the other near the ca locus

  11. Integration mockup and process material management system

    Science.gov (United States)

    Verble, Adas James, Jr.

    1992-01-01

    Work to define and develop a full scale Space Station Freedom (SSF) mockup with the flexibility to evolve into future designs, to validate techniques for maintenance and logistics and verify human task allocations and support trade studies is described. This work began in early 1985 and ended in August, 1991. The mockups are presently being used at MSFC in Building 4755 as a technology and design testbed, as well as for public display. Micro Craft also began work on the Process Material Management System (PMMS) under this contract. The PMMS simulator was a sealed enclosure for testing to identify liquids, gaseous, particulate samples, and specimen including, urine, waste water, condensate, hazardous gases, surrogate gasses, liquids, and solids. The SSF would require many trade studies to validate techniques for maintenance and logistics and verify system task allocations; it was necessary to develop a full scale mockup which would be representative of current SSF design with the ease of changing those designs as the SSF design evolved and changed. The tasks defined for Micro Craft were to provide the personnel, services, tools, and materials for the SSF mockup which would consist of four modules, nodes, interior components, and part task mockups of MSFC responsible engineering systems. This included the Engineering Control and Life Support Systems (ECLSS) testbed. For the initial study, the mockups were low fidelity, soft mockups of graphics art bottle, and other low cost materials, which evolved into higher fidelity mockups as the R&D design evolved, by modifying or rebuilding, an important cost saving factor in the design process. We designed, fabricated, and maintained the full size mockup shells and support stands. The shells consisted of cylinders, end cones, rings, longerons, docking ports, crew airlocks, and windows. The ECLSS required a heavier cylinder to support the ECLSS systems test program. Details of this activity will be covered. Support stands were

  12. DNA repair genes

    International Nuclear Information System (INIS)

    Morimyo, Mitsuoki

    1995-01-01

    Fission yeast S. pombe is assumed to be a good model for cloning of human DNA repair genes, because human gene is normally expressed in S. pombe and has a very similar protein sequence to yeast protein. We have tried to elucidate the DNA repair mechanisms of S. pombe as a model system for those of mammals. (J.P.N.)

  13. Drug-Loadable Calcium Alginate Hydrogel System for Use in Oral Bone Tissue Repair.

    Science.gov (United States)

    Chen, Luyuan; Shen, Renze; Komasa, Satoshi; Xue, Yanxiang; Jin, Bingyu; Hou, Yepo; Okazaki, Joji; Gao, Jie

    2017-05-06

    This study developed a drug-loadable hydrogel system with high plasticity and favorable biological properties to enhance oral bone tissue regeneration. Hydrogels of different calcium alginate concentrations were prepared. Their swelling ratio, degradation time, and bovine serum albumin (BSA) release rate were measured. Human periodontal ligament cells (hPDLCs) and bone marrow stromal cells (BMSCs) were cultured with both calcium alginate hydrogels and polylactic acid (PLA), and then we examined the proliferation of cells. Inflammatory-related factor gene expressions of hPDLCs and osteogenesis-related gene expressions of BMSCs were observed. Materials were implanted into the subcutaneous tissue of rabbits to determine the biosecurity properties of the materials. The materials were also implanted in mandibular bone defects and then scanned using micro-CT. The calcium alginate hydrogels caused less inflammation than the PLA. The number of mineralized nodules and the expression of osteoblast-related genes were significantly higher in the hydrogel group compared with the control group. When the materials were implanted in subcutaneous tissue, materials showed favorable biocompatibility. The calcium alginate hydrogels had superior osteoinductive bone ability to the PLA. The drug-loadable calcium alginate hydrogel system is a potential bone defect reparation material for clinical dental application.

  14. Croatian National System of Nuclear Materials Control

    International Nuclear Information System (INIS)

    Biscan, R.

    1998-01-01

    In the process of economic and technological development of Croatia by using or introducing nuclear power or in the case of international co-operation in the field of peaceful nuclear activities, including international exchange of nuclear material, Croatia should establish and implement National System of Nuclear Materials Control. Croatian National System of accounting for and control of all nuclear material will be subjected to safeguards under requirements of Agreement and Additional Protocol between the Republic of Croatia and the International Atomic Energy Agency (IAEA) for the Application of Safeguards in Connection with the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). The decision by NPT parties at the 1995 NPT Review and Extension Conference to endorse the Fullscope IAEA Safeguards Standard (FSS) as a necessary precondition of nuclear supply means that states are obliged to ensure that the recipient country has a FSS agreement in place before any nuclear transfer can take place (Ref. 1). The FSS standard of nuclear supply is a central element of the Nuclear Suppliers Group (NSG) Guidelines which the NSG adopted in 1992 and should be applied to members and non-members of the NSG. The FSS standard of nuclear supply in general allows for NPT parties or countries which have undertaken the same obligations through other treaty arrangements, to receive favourable treatment in nuclear supply arrangements. However, the Iraqi experience demonstrate that trade in nuclear and dual-use items, if not properly monitored, can contribute to a nuclear weapons program in countries acting contrary to their non-proliferation obligation. Multilateral nuclear export control mechanisms, including the FSS supply standard, provide the basis for co-ordination and standardisation of export control measures. (author)

  15. Cell and biomolecule delivery for tissue repair and regeneration in the central nervous system.

    Science.gov (United States)

    Elliott Donaghue, Irja; Tam, Roger; Sefton, Michael V; Shoichet, Molly S

    2014-09-28

    Tissue engineering frequently involves cells and scaffolds to replace damaged or diseased tissue. It originated, in part, as a means of effecting the delivery of biomolecules such as insulin or neurotrophic factors, given that cells are constitutive producers of such therapeutic agents. Thus cell delivery is intrinsic to tissue engineering. Controlled release of biomolecules is also an important tool for enabling cell delivery since the biomolecules can enable cell engraftment, modulate inflammatory response or otherwise benefit the behavior of the delivered cells. We describe advances in cell and biomolecule delivery for tissue regeneration, with emphasis on the central nervous system (CNS). In the first section, the focus is on encapsulated cell therapy. In the second section, the focus is on biomolecule delivery in polymeric nano/microspheres and hydrogels for the nerve regeneration and endogenous cell stimulation. In the third section, the focus is on combination strategies of neural stem/progenitor cell or mesenchymal stem cell and biomolecule delivery for tissue regeneration and repair. In each section, the challenges and potential solutions associated with delivery to the CNS are highlighted. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. The development of robotic system for inspecting and repairing NPP primary coolant system of high-level radioactive environment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Ho; Kim, Ki Ho; Jung, Seung Ho; Kim, Byung Soo; Hwang, Suk Yeoung; Kim, Chang Hoi; Seo, Yong Chil; Lee, Young Kwang; Lee, Yong Bum; Cho, Jai Wan; Lee, Jae Kyung; Lee, Yong Deok

    1997-07-01

    This project aims at developing a robotic system to automatically handle inspection and maintenance of NPP safety-related facilities in high-level radioactive environment. This robotic system under development comprises two robots depending on application fields - a mobile robot and multi-functional robot. The mobile robot is designed to be used in the area of primary coolant system during the operation of NPP. This robot enables to overcome obstacles and perform specified tasks in unstructured environment. The multi-functional robot is designed for performing inspection and maintenance tasks of steam generator and nuclear reactor vessel during the overhaul periods of NPP. Nuclear facilities can be inspected and repaired all the time by use of both the mobile robot and the multi-functional robot. Human operator, by teleoperation, monitors the movements of such robots located at remote task environment via video cameras and controls those remotely generating desired commands via master manipulator. We summarize the technology relating to the application of the mobile robot to primary coolant system environment, the applicability of the mobile robot through 3D graphic simulation, the design of the mobile robot, the design of its radiation-hardened controller. We also describe the mechanical design, modeling, and control system of the multi-functional robot. Finally, we present the design of the force-reflecting master and the modeling of virtual task environment for a training simulator. (author). 47 refs., 16 tabs., 43 figs.

  17. The development of robotic system for inspecting and repairing NPP primary coolant system of high-level radioactive environment

    International Nuclear Information System (INIS)

    Kim, Seung Ho; Kim, Ki Ho; Jung, Seung Ho; Kim, Byung Soo; Hwang, Suk Yeoung; Kim, Chang Hoi; Seo, Yong Chil; Lee, Young Kwang; Lee, Yong Bum; Cho, Jai Wan; Lee, Jae Kyung; Lee, Yong Deok.

    1997-07-01

    This project aims at developing a robotic system to automatically handle inspection and maintenance of NPP safety-related facilities in high-level radioactive environment. This robotic system under development comprises two robots depending on application fields - a mobile robot and multi-functional robot. The mobile robot is designed to be used in the area of primary coolant system during the operation of NPP. This robot enables to overcome obstacles and perform specified tasks in unstructured environment. The multi-functional robot is designed for performing inspection and maintenance tasks of steam generator and nuclear reactor vessel during the overhaul periods of NPP. Nuclear facilities can be inspected and repaired all the time by use of both the mobile robot and the multi-functional robot. Human operator, by teleoperation, monitors the movements of such robots located at remote task environment via video cameras and controls those remotely generating desired commands via master manipulator. We summarize the technology relating to the application of the mobile robot to primary coolant system environment, the applicability of the mobile robot through 3D graphic simulation, the design of the mobile robot, the design of its radiation-hardened controller. We also describe the mechanical design, modeling, and control system of the multi-functional robot. Finally, we present the design of the force-reflecting master and the modeling of virtual task environment for a training simulator. (author). 47 refs., 16 tabs., 43 figs

  18. Improving the Repair Planning System for Mining Equipment on the Basis of Non-destructive Evaluation Data

    Science.gov (United States)

    Drygin, Michael; Kuryshkin, Nicholas

    2017-11-01

    The article tells about forming a new concept of scheduled preventive repair system of the equipment at coal mining enterprises, based on the use of modem non-destructive evaluation methods. The approach to the solution for this task is based on the system-oriented analysis of the regulatory documentation, non-destructive evaluation methods and means, experimental studies with compilation of statistics and subsequent grapho-analytical analysis. The main result of the work is a feasible explanation of using non-destructive evaluation methods within the current scheduled preventive repair system, their high efficiency and the potential of gradual transition to condition-based maintenance. In practice wide use of nondestructive evaluation means w;ill allow to reduce significantly the number of equipment failures and to repair only the nodes in pre-accident condition. Considering the import phase-out policy, the solution for this task will allow to adapt the SPR system to Russian market economy conditions and give the opportunity of commercial move by reducing the expenses for maintenance of Russian-made and imported equipment.

  19. Materials issues in accelerator driven-systems

    International Nuclear Information System (INIS)

    Al Mazouzi, A.

    2008-01-01

    Full text of publication follows. Nuclear energy has to cope with critical topics to resolve the economical question of increasing energy demand and, in particular, the public acceptability demands: - increasing the absolute safety of the installations; - managing more efficiently the nuclear waste; In that respect, the development of a new type of nuclear installation coping with above constraints of technological as well as socio-economical nature may be of high importance for the future of sustainable energy provision. An accelerator-driven system (ADS) - a subcritical core, operated as a waste burner for minor actinides (MAs) and long-lived fission products (LLFPs) or as nuclear amplifier for energy production, fed with primary neutrons by a spallation source - has the potential to cope with above constraints and to pave the way to a more environmentally safe and acceptable nuclear energy production. Within the framework of EUROTRANS, the European community has launched a broad R and D programme in collaboration with partners from Europe and abroad (USA, Japan), to address the technical, technological and fundamental issues related to the realisation of an experimental machine that is intended to allow: - continuation, and extension of the present knowledge towards ADS, in the field of reactor materials, fuel and reactor physics research; - enhancement and triggering of new R and D activities such as nuclear waste transmutation, ADS technology, liquid metal embrittlement, The present lecture will cover the main aspects of the design of an experimental XT-ADS taking as example the work that has been performed at SCK.CEN within MYRRHA project. The safety aspect of such machine will be addressed on terms of structural material performance, with emphasis on issues related to the interaction between structural materials (austenitic and ferritic martensitic steels) and the liquid metal coolant (lead-alloys). Finally, a discussion will be given on the open issues and

  20. Dependability estimation for non-Markov consecutive-k-out-of-n: F repairable systems by fast simulation

    International Nuclear Information System (INIS)

    Xiao Gang; Li Zhizhong; Li Ting

    2007-01-01

    A model of consecutive-k-out-of-n: F repairable system with non-exponential repair time distribution and (k-1)-step Markov dependence is introduced in this paper along with algorithms of three Monte Carlo methods, i.e. importance sampling, conditional expectation estimation and combination of the two methods, to estimate dependability of the non-Markov model including reliability, transient unavailability, MTTF, and MTBF. A numerical example is presented to demonstrate the efficiencies of above methods. The results show that combinational method has the highest efficiency for estimation of unreliability and unavailability, while conditional expectation estimation is the most efficient method for estimation of MTTF and MTBF. Conditional expectation estimation seems to have overall higher speedups in estimating dependability of such systems

  1. Comparison of the Mismatch Repair System between Primary and Metastatic Colorectal Cancers Using Immunohistochemistry

    Directory of Open Access Journals (Sweden)

    Jiyoon Jung

    2017-03-01

    Full Text Available Background Colorectal cancer (CRC is one of the most common malignancies worldwide. Approximately 10%–15% of the CRC cases have defective DNA mismatch repair (MMR genes. Although the high level of microsatellite instability status is a predictor of favorable outcome in primary CRC, little is known about its frequency and importance in secondary CRC. Immunohistochemical staining (IHC for MMR proteins (e.g., MLH1, MSH2, MSH6, and PMS2 has emerged as a useful technique to complement polymerase chain reaction (PCR analyses. Methods In this study, comparison between the MMR system of primary CRCs and paired liver and lung metastatic lesions was done using IHC and the correlation with clinical outcomes was also examined. Results Based on IHC, 7/61 primary tumors (11.4% showed deficient MMR systems, while 13/61 secondary tumors (21.3% showed deficiencies. In total, 44 cases showed proficient expression in both the primary and metastatic lesions. Three cases showed deficiencies in both the primary and paired metastatic lesions. In 10 cases, proficient expression was found only in the primary lesions, and not in the corresponding metastatic lesions. In four cases, proficient expression was detected in the secondary tumor, but not in the primary tumor. Conclusions Although each IHC result and the likely defective genes were not exactly matched between the primary and the metastatic tumors, identical results for primary and metastatic lesions were obtained in 77% of the cases (47/61. These data are in agreement with the previous microsatellite detection studies that used PCR and IHC.

  2. Ranking of small scale proposals for water system repair using the Rapid Impact Assessment Matrix (RIAM)

    Energy Technology Data Exchange (ETDEWEB)

    Shakib-Manesh, T.E.; Hirvonen, K.O.; Jalava, K.J.; Ålander, T.; Kuitunen, M.T., E-mail: markku.kuitunen@jyu.fi

    2014-11-15

    Environmental impacts of small scale projects are often assessed poorly, or not assessed at all. This paper examines the usability of the Rapid Impact Assessment Matrix (RIAM) as a tool to prioritize project proposals for small scale water restoration projects in relation to proposals' potential to improve the environment. The RIAM scoring system was used to assess and rank the proposals based on their environmental impacts, the costs of the projects to repair the harmful impacts, and the size of human population living around the sites. A four-member assessment group (The expert panel) gave the RIAM-scores to the proposals. The assumed impacts of the studied projects at the Eastern Finland water systems were divided into the ecological and social impacts. The more detailed assessment categories of the ecological impacts in this study were impacts on landscape, natural state, and limnology. The social impact categories were impacts to recreational use of the area, fishing, industry, population, and economy. These impacts were scored according to their geographical and social significance, their magnitude of change, their character, permanence, reversibility, and cumulativeness. The RIAM method proved to be an appropriate and recommendable method for the small-scale assessment and prioritizing of project proposals. If the assessments are well documented, the RIAM can be a method for easy assessing and comparison of the various kinds of projects. In the studied project proposals there were no big surprises in the results: the best ranks were received by the projects, which were assumed to return watersheds toward their original state.

  3. Ranking of small scale proposals for water system repair using the Rapid Impact Assessment Matrix (RIAM)

    International Nuclear Information System (INIS)

    Shakib-Manesh, T.E.; Hirvonen, K.O.; Jalava, K.J.; Ålander, T.; Kuitunen, M.T.

    2014-01-01

    Environmental impacts of small scale projects are often assessed poorly, or not assessed at all. This paper examines the usability of the Rapid Impact Assessment Matrix (RIAM) as a tool to prioritize project proposals for small scale water restoration projects in relation to proposals' potential to improve the environment. The RIAM scoring system was used to assess and rank the proposals based on their environmental impacts, the costs of the projects to repair the harmful impacts, and the size of human population living around the sites. A four-member assessment group (The expert panel) gave the RIAM-scores to the proposals. The assumed impacts of the studied projects at the Eastern Finland water systems were divided into the ecological and social impacts. The more detailed assessment categories of the ecological impacts in this study were impacts on landscape, natural state, and limnology. The social impact categories were impacts to recreational use of the area, fishing, industry, population, and economy. These impacts were scored according to their geographical and social significance, their magnitude of change, their character, permanence, reversibility, and cumulativeness. The RIAM method proved to be an appropriate and recommendable method for the small-scale assessment and prioritizing of project proposals. If the assessments are well documented, the RIAM can be a method for easy assessing and comparison of the various kinds of projects. In the studied project proposals there were no big surprises in the results: the best ranks were received by the projects, which were assumed to return watersheds toward their original state

  4. Advanced materials for thermal protection system

    Science.gov (United States)

    Heng, Sangvavann; Sherman, Andrew J.

    1996-03-01

    Reticulated open-cell ceramic foams (both vitreous carbon and silicon carbide) and ceramic composites (SiC-based, both monolithic and fiber-reinforced) were evaluated as candidate materials for use in a heat shield sandwich panel design as an advanced thermal protection system (TPS) for unmanned single-use hypersonic reentry vehicles. These materials were fabricated by chemical vapor deposition/infiltration (CVD/CVI) and evaluated extensively for their mechanical, thermal, and erosion/ablation performance. In the TPS, the ceramic foams were used as a structural core providing thermal insulation and mechanical load distribution, while the ceramic composites were used as facesheets providing resistance to aerodynamic, shear, and erosive forces. Tensile, compressive, and shear strength, elastic and shear modulus, fracture toughness, Poisson's ratio, and thermal conductivity were measured for the ceramic foams, while arcjet testing was conducted on the ceramic composites at heat flux levels up to 5.90 MW/m2 (520 Btu/ft2ṡsec). Two prototype test articles were fabricated and subjected to arcjet testing at heat flux levels of 1.70-3.40 MW/m2 (150-300 Btu/ft2ṡsec) under simulated reentry trajectories.

  5. Radioactive materials system of the ININ (SMATRAD)

    International Nuclear Information System (INIS)

    Rivero G, E.; Ledezma F, L.E.; Valdivia R, D.

    2007-01-01

    The radioactive iodine (I-131) it is an isotope created starting from the iodine with the purpose of emitting radiation for medicinal use. When a small dose of I-131 is ingested, this is absorbed in the sanguine torrent in the gastrointestinal tract (Gl) and it is concentrated by the blood on the thyroid gland, where it begins to destroy the cells. This treatment makes that the activity of the thyroid decreases in great measure and in some cases it can transform an hyperactive thyroid in a hypoactive thyroid which requires additional treatments. The sodium iodide I-131 is one of the products elaborated and marketed by the ININ in the Radiopharmaceuticals and Radioisotopes production plant, dependent of the Radioactive Material Department of the Nuclear Applications in the Health Management. The Plant is the only one in its type that exists in the country, it has Sanitary License and Good Practice of Production Certificate, emitted by the Secretary of Health, and licenses for the handling and the transportation of radioactive material, sent by the National Commission of Nuclear Safety and Safeguards. Also, the quality system of the plant is certified under the ISO 9001:2000 standard. (Author)

  6. Selected technological problems of repair of hydraulic drive systems for shearer loaders with the example of A2V-107 pumps and SHT-630W motors

    Energy Technology Data Exchange (ETDEWEB)

    Kusak, E.; Paluch, J.

    1983-07-01

    Major elements of hydraulic drive systems as well as their wear and repair characteristics are described. Types of wear and standardized repair methods are comparatively evaluated. The evaluations are aimed at development of standardized procedures for use in large repair shops. The following stages of repair operations of A2V-107 pumps and SHT-630W motors are analyzed: disassembling hydraulic systems, washing and cleaning, classification of equipment elements (elements for scrapping and for regeneration), regeneration, assembling and final tests. The following regeneration methods are discussed: cutting, burnishing, bushing (e.g. the Heli Coil method), regeneration using copper, tin or zinc dusts and a temperature from 950 to 1,000 K under inert atmosphere, heat treatments. Methods are reviewed for comparative evaluations of repair efficiency and repair quality as well as documents used for recording repair in the shops. Economic aspects of using standardized procedures for repair of hydraulic equipment for shearer loaders are discussed and recommendations are made. (6 refs.)

  7. PMS2 gene mutation results in DNA mismatch repair system failure in a case of adult granulosa cell tumor

    OpenAIRE

    Wang, Wen-Chung; Lee, Ya-Ting; Lai, Yen-Chein

    2017-01-01

    Background Granulosa cell tumors are rare ovarian malignancies. Their characteristics include unpredictable indolent growth with malignant potential and late recurrence. Approximately 95% are of adult type. Recent molecular studies have characterized the FOXL2 402C?>?G mutation in adult granulosa cell tumor. Our previous case report showed that unique FOXL2 402C?>?G mutation and defective DNA mismatch repair system are associated with the development of adult granulosa cell tumor. Findings In...

  8. Repair of damaged DNA in vivo: Final technical report

    International Nuclear Information System (INIS)

    Hanawalt, P.C.

    1987-09-01

    This contract was initiated in 1962 with the US Atomic Energy Commission to carry out basic research on the effects of radiation on the process of DNA replication in bacteria. Within the first contract year we discovered repair replication at the same time that Setlow and Carrier discovered pyrimidine dimer excision. These discoveries led to the elucidation of the process of excision-repair, one of the most important mechanisms by which living systems, including humans, respond to structural damage in their genetic material. We improved methodology for distinguishing repair replication from semiconservative replication and instructed others in these techniques. Painter then was the first to demonstrate repair replication in ultraviolet irradiated human cells. He, in turn, instructed James Cleaver who discovered that skin fibroblasts from patients with xeroderma pigmentosum were defective in excision-repair. People with this genetic defect are extremely sensitive to sunlight and they develop carcinomas and melanomas of the skin with high frequency. The existence of this hereditary disease attests to the importance of DNA repair in man. We certainly could not survive in the normal ultraviolet flux from the sun if our DNA were not continuously monitored for damage and repaired. Other hereditary diseases such as ataxia telangiectasia, Cockayne's syndrome, Blooms syndrome and Fanconi's anemia also involve deficiencies in DNA damage processing. The field of DNA repair has developed rapidly as we have learned that most environmental chemical carcinogens as well as radiation produce repairable damage in DNA. 251 refs

  9. Material control system simulator user's manual

    Energy Technology Data Exchange (ETDEWEB)

    Hollstien, R.B.

    1978-01-24

    This report describes the use of a Material Control System Simulator (MCSS) program for determination of material accounting uncertainty and system response to particular adversary action sequences that constitute plausible material diversion attempts. The program is intended for use in situations where randomness, uncertainty, or interaction of adversary actions and material control system components make it difficult to assess safeguards effectiveness against particular material diversion attempts.

  10. Application of BIM technology in green building material management system

    Science.gov (United States)

    Zhineng, Tong

    2018-06-01

    The current green building materials management system in China's construction industry is not perfect, and there are still many shortcomings. Active construction of green building materials management system based on BIM technology, combined with the characteristics of green building materials and its relationship with BIM technology application, is urgently needed to better realize the scientific management of green building materials.

  11. Efficacy and safety of Elevate® system on apical and anterior compartment prolapse repair with personal technique modification

    Directory of Open Access Journals (Sweden)

    Daniele Castellani

    Full Text Available ABSTRACT Aim: To evaluate the effectiveness and safety of Anterior Elevate® mesh kit system (AES in woman with symptomatic stage 3 or 4 anterior and/or apical pelvic organ prolapse (POP. Materials and Methods: This retrospective, monocentric, single surgeon study enrolled between May 2010 and January 2013 fifty-six woman experiencing symptomatic anterior vaginal prolapse with or without apical descent (POP-Q stage 3 or 4. All women received a AES and 7 (12.5% received a concomitant transvaginal hysterectomy. Primary endpoint was anatomic correction of prolapse; success was defined as POP-Q stage ≤ 1 or asymptomatic stage 2. Secondary endpoints were quality-of-life (QOL results and patients' safety outcomes, which were assessed by 3 validated self-reporting questionnaires at baseline and annually: ICIQ-UI short form, ICIQ-VS and P-QOL. All patients completed 2-years and 28 women 3-years of follow-up. Surgical approach was modified in women with uterus, moving the two-propylene strips anteriorly around the cervix itself crossing one another, so the left will take place in the right side and the right on the opposite. This modification was made in order to better support the uterus. Results: Vaginal mesh exposure was present in 3 (5,3% patients. Very good anatomical outcomes were seen, with one (1,8% failure at 6-months, 4 (7,1% at 1-year, 6 at 2-years (10,7%. Statistically significant improvements were seen in the ICIQ-VS and P-QOL questionnaires throughout follow-up. Conclusion: Our data suggest that AES is a minimally-invasive transvaginal procedure to repair anterior and apical POP, with good evidence related to mid-term safety and efficacy.

  12. Repair of X-ray-induced single-strand breaks by a cell-free system

    International Nuclear Information System (INIS)

    Seki, Shuji; Ikeda, Shogo; Tsutui, Ken; Teraoka, Hirobumi

    1990-01-01

    Repair of X-ray-induced single-strand breaks of DNA was studied in vitro using an exonuclease purified from mouse ascites sarcoma (SR-C3H/He) cells. X-ray-dose-dependent unscheduled DNA synthesis was primed by the exonuclease. Repair of X-ray-induced single-strand breaks in pUC19 plasmid DNA was demonstrated by agarose gel electrophoresis after incubating the damaged DNA with the exonuclease, DNA polymerase (Klenow fragment of DNA polymerase I or DNA polymerase β purified from SR-C3H/He cells), four deoxynucleoside triphosphates, ATP and DNA ligase (T4 DNA ligase or DNA ligase I purified from calf thymus). The present results suggested that the exonuclease is involved in the initiation of repair of X-ray-induced single-strand breaks in removing 3' ends of X-ray-damaged DNA. (author)

  13. Lightweight Open-Cell Scaffolds from Sea Urchin Spines with Superior Material Properties for Bone Defect Repair.

    Science.gov (United States)

    Cao, Lei; Li, Xiaokang; Zhou, Xiaoshu; Li, Yong; Vecchio, Kenneth S; Yang, Lina; Cui, Wei; Yang, Rui; Zhu, Yue; Guo, Zheng; Zhang, Xing

    2017-03-22

    Sea urchin spines (Heterocentrotus mammillatus), with a hierarchical open-cell structure similar to that of human trabecular bone and superior mechanical property (compressive strength ∼43.4 MPa) suitable for machining to shape, were explored for potential applications of bone defect repair. Finite element analyses reveal that the compressive stress concentrates along the dense growth rings and dissipates through strut structures of the stereoms, indicating that the exquisite mesostructures play an important role in high strength-to-weight ratios. The fracture strength of magnesium-substituted tricalcium phosphate (β-TCMP) scaffolds produced by hydrothermal conversion of urchin spines is about 9.3 MPa, comparable to that of human trabecular bone. New bone forms along outer surfaces of β-TCMP scaffolds after implantation in rabbit femoral defects for one month and grows into the majority of the inner open-cell spaces postoperation in three months, showing tight interface between the scaffold and regenerative bone tissue. Fusion of beagle lumbar facet joints using a Ti-6Al-4V cage and β-TCMP scaffold can be completed within seven months with obvious biodegradation of the β-TCMP scaffold, which is nearly completely degraded and replaced by newly formed bone ten months after implantation. Thus, sea urchin spines suitable for machining to shape have advantages for production of biodegradable artificial grafts for bone defect repair.

  14. Technology of Double Thermal Insulation for the Repair and Energy Optimization of Existing Thermal Insulation Composite Systems

    Science.gov (United States)

    Belániová, Barbora; Antošová, Naďa

    2017-06-01

    The theme of improvement thermal proprieties of external cladding according to the New EU Directive is still a hot topic, which needs to be answered necessarily till December 2020. Maintenance and repair of existing ETICS became to also an actual open theme in search solutions for existing constructions. The aim of the research in this review is to analyze influence of layers the alternative thermal materials in technology "double thermal insulation". Humidity and temperature conditions will be further examined in connection with the development and colonization of microorganisms on surface construction.

  15. Outcomes of Endovascular Aneurysm Repair using the Ovation Stent Graft System in Adverse Anatomy.

    Science.gov (United States)

    Greaves, Nicholas S; Moore, Aiden; Seriki, Dare; Ghosh, Jonathan

    2018-04-01

    The aim was the evaluation of mid-term efficacy and safety outcome measures for the Ovation (Endologix, Santa Rosa, CA, USA) stent graft system in the management of infrarenal abdominal aortic aneurysms (iAAA) with adverse anatomy. A retrospective observational study of all patients undergoing elective iAAA repair was carried out from 2012 to 2017 using Ovation Prime or iX stent grafts with a minimum of 3 months follow-up at a single UK vascular centre. Post-operative surveillance involved computed tomography scans at 3 months and 1 year, with duplex ultrasound yearly thereafter. Outcome measures were established with retrospective analysis of pre- and post-operative imaging, and included peri-operative mortality, major adverse events, limb complications, aneurysm diameter change, and endoleak rates. All patients were within Ovation instructions for use (IFU), and assessment was made to determine whether aneurysms had anatomical features considered adverse for other commonly used stent graft platforms. Ovation stent grafts were implanted in 52 patients (79% male, mean age 75.7 years) with a mean aneurysm diameter of 62.5 mm (range 55-107 mm). There was 100% technical deployment success. The 30 day mortality was 0% and there was no aneurysm related mortality during follow-up (median 24 months, range 3-48 months). There were no type I or III endoleaks, but 19% developed type II endoleaks with one patient requiring re-intervention. No iliac limb occlusions were identified but one case required relining for limb kinking. All 52 cases were within the IFU for Ovation but only 12% met the IFU criteria for the Cook and Medtronic devices. The mid-term experience with Ovation demonstrates safe, durable treatment of iAAAs, including those with unfavourable anatomy, frequently off IFU for other commonly used devices. Copyright © 2017 European Society for Vascular Surgery. Published by Elsevier B.V. All rights reserved.

  16. The effect of caffeine on repair systems in oocytes of Drosophila melanogaster

    International Nuclear Information System (INIS)

    Mendelson, D.

    1976-01-01

    Irradiated males were mated to females that had received treatment with caffeine or honey (by feeding), and the frequencies of sex-chromosome losses and chromosome rearrangements induced in mature spermatozoa of the males were compared. Caffeine treatment led to an enhancement of the frequencies of sex-chromosome loss and a decrease in those of rearrangements. These findings can be interpreted on the assumption that caffeine inhibits repair and misrepair processes that are active in the oocytes. Caffeine treatment administered to one of the female stocks used in these studies was without any effect, presumably because of the absence of a caffeine-sensitive repair mechanism in the oocytes

  17. Geothermal systems materials: a workshop/symposium

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    Sixteen papers are included. A separate abstract was prepared for each. Summaries of workshops on the following topics are also included in the report: non-metallic materials, corrosion, materials selection, fluid chemistry, and failure analysis. (MHR)

  18. Simulation based analysis and an application to an offshore oil and gas production system of the Natvig measures of component importance in repairable systems

    International Nuclear Information System (INIS)

    Natvig, Bent; Eide, Kristina A.; Gasemyr, Jorund; Huseby, Arne B.; Isaksen, Stefan L.

    2009-01-01

    In the present paper the Natvig measures of component importance for repairable systems, and its extended version are analyzed for two three-component systems and a bridge system. The measures are also applied to an offshore oil and gas production system. According to the extended version of the Natvig measure a component is important if both by failing it strongly reduces the expected system uptime and by being repaired it strongly reduces the expected system downtime. The results include a study of how different distributions affect the ranking of the components. All numerical results are computed using discrete event simulation. In a companion paper [Huseby AB, Eide KA, Isaksen SL, Natvig B, Gasemyr, J. Advanced discrete event simulation methods with application to importance measure estimation. 2009, submitted for publication] the advanced simulation methods needed in these calculations are described.

  19. DNA repair protocols

    DEFF Research Database (Denmark)

    Bjergbæk, Lotte

    In its 3rd edition, this Methods in Molecular Biology(TM) book covers the eukaryotic response to genomic insult including advanced protocols and standard techniques in the field of DNA repair. Offers expert guidance for DNA repair, recombination, and replication. Current knowledge of the mechanisms...... that regulate DNA repair has grown significantly over the past years with technology advances such as RNA interference, advanced proteomics and microscopy as well as high throughput screens. The third edition of DNA Repair Protocols covers various aspects of the eukaryotic response to genomic insult including...... recent advanced protocols as well as standard techniques used in the field of DNA repair. Both mammalian and non-mammalian model organisms are covered in the book, and many of the techniques can be applied with only minor modifications to other systems than the one described. Written in the highly...

  20. Nonterrestrial material processing and manufacturing of large space systems

    Science.gov (United States)

    Von Tiesenhausen, G.

    1979-01-01

    Nonterrestrial processing of materials and manufacturing of large space system components from preprocessed lunar materials at a manufacturing site in space is described. Lunar materials mined and preprocessed at the lunar resource complex will be flown to the space manufacturing facility (SMF), where together with supplementary terrestrial materials, they will be final processed and fabricated into space communication systems, solar cell blankets, radio frequency generators, and electrical equipment. Satellite Power System (SPS) material requirements and lunar material availability and utilization are detailed, and the SMF processing, refining, fabricating facilities, material flow and manpower requirements are described.

  1. PMS2 gene mutation results in DNA mismatch repair system failure in a case of adult granulosa cell tumor.

    Science.gov (United States)

    Wang, Wen-Chung; Lee, Ya-Ting; Lai, Yen-Chein

    2017-03-27

    Granulosa cell tumors are rare ovarian malignancies. Their characteristics include unpredictable indolent growth with malignant potential and late recurrence. Approximately 95% are of adult type. Recent molecular studies have characterized the FOXL2 402C > G mutation in adult granulosa cell tumor. Our previous case report showed that unique FOXL2 402C > G mutation and defective DNA mismatch repair system are associated with the development of adult granulosa cell tumor. In this study, the DNA sequences of four genes, MSH2, MLH1, MSH6, and PMS2, in the DNA mismatch repair system were determined via direct sequencing to elucidate the exact mechanism for the development of this granulosa cell tumor. The results showed that two missense germline mutations, T485K and N775L, inactivate the PMS2 gene. The results of this case study indicated that although FOXL2 402C > G mutation determines the development of granulosa cell tumor, PMS2 mutation may be the initial driver of carcinogenesis. Immunohistochemistry-based tumor testing for mismatch repair gene expression may be necessary for granulosa cell tumors to determine their malignant potential or if they are part of Lynch syndrome.

  2. Endoscopic augmentation of the lower esophageal sphincter for the treatment of gastroesophageal reflux disease: Multicenter study of the gatekeeper reflux repair system

    NARCIS (Netherlands)

    Fockens, P.; Bruno, M. J.; Gabbrielli, A.; Odegaard, S.; Hatlebakk, J.; Allescher, H. D.; Rösch, T.; Rhodes, M.; Bastid, C.; Rey, J.; Boyer, J.; Muehldorffer, S.; van den Hombergh, U.; Costamagna, G.

    2004-01-01

    Background and Study Aims: The safety and effectiveness of the Gatekeeper Reflux Repair System (Medtronic Europe, Tolochenaz, Switzerland) in the treatment of gastroesophageal reflux disease (GERD) was evaluated. This new, reversible treatment modality involves the endoscopic introduction of

  3. Laparoscopic Inguinal Hernia Repair in a Developing Nation: Short ...

    African Journals Online (AJOL)

    bilateral hernias, and recurrent hernias), there are data demonstrating an ... no reports of laparoscopic inguinal hernia repair from the. Anglophone ... MATERIALS AND METHODS .... inguinal hernia repair has advantages over open repair for.

  4. Clustered DNA lesions containing 5-formyluracil and AP site: repair via the BER system.

    Directory of Open Access Journals (Sweden)

    Ekaterina A Belousova

    Full Text Available Lesions in the DNA arise under ionizing irradiation conditions or various chemical oxidants as a single damage or as part of a multiply damaged site within 1-2 helical turns (clustered lesion. Here, we explored the repair opportunity of the apurinic/apyrimidinic site (AP site composed of the clustered lesion with 5-formyluracil (5-foU by the base excision repair (BER proteins. We found, that if the AP site is shifted relative to the 5-foU of the opposite strand, it could be repaired primarily via the short-patch BER pathway. In this case, the cleavage efficiency of the AP site-containing DNA strand catalyzed by human apurinic/apyrimidinic endonuclease 1 (hAPE1 decreased under AP site excursion to the 3'-side relative to the lesion in the other DNA strand. DNA synthesis catalyzed by DNA polymerase lambda was more accurate in comparison to the one catalyzed by DNA polymerase beta. If the AP site was located exactly opposite 5-foU it was expected to switch the repair to the long-patch BER pathway. In this situation, human processivity factor hPCNA stimulates the process.

  5. Complex catalysts from self-repairing ensembles to highly reactive air-based oxidation systems

    Science.gov (United States)

    Craig L. Hill; Laurent Delannoy; Dean C. Duncan; Ira A. Weinstock; Roman F. Renneke; Richard S. Reiner; Rajai H. Atalla; Jong Woo Han; Daniel A. Hillesheim; Rui Cao; Travis M. Anderson; Nelya M. Okun; Djamaladdin G. Musaev; Yurii V. Geletii

    2007-01-01

    Progress in four interrelated catalysis research efforts in our laboratory are summarized: (1) catalytic photochemical functionalization of unactivated CeH bonds by polyoxometalates (POMs); (2) self-repairing catalysts; (3) catalysts for air-based oxidations under ambient conditions; and (4) terminal oxo complexes of the late-transition metal elements and their...

  6. The development of remote repairing system, decontamination and in-cell remote inspection equipment

    International Nuclear Information System (INIS)

    Ishibashi, Yuzo; Toyoda, Osamu; Haginoya, Isao; Yamamoto, Ryuichi; Tanaka, Yasumasa

    1993-01-01

    PNC has been developing remote repair and inspection technologies for in-cell components in reprocessing Plants. In this report, several remote technologies such as remote dismantling and removal, decontamination, remote pipe maintenance and remote in-cell inspection equipment are described. (author)

  7. DNA repair in human cells

    International Nuclear Information System (INIS)

    Regan, J.D.; Carrier, W.L.; Kusano, I.; Furuno-Fukushi, I.; Dunn, W.C. Jr.; Francis, A.A.; Lee, W.H.

    1982-01-01

    Our primary objective is to elucidate the molecular events in human cells when cellular macromolecules such as DNA are damaged by radiation or chemical agents. We study and characterize (i) the sequence of DNA repair events, (ii) the various modalities of repair, (iii) the genetic inhibition of repair due to mutation, (iv) the physiological inhibition of repair due to mutation, (v) the physiological inhibition of repair due to biochemical inhibitors, and (vi) the genetic basis of repair. Our ultimate goals are to (i) isolate and analyze the repair component of the mutagenic and/or carcinogenic event in human cells, and (ii) elucidate the magnitude and significance of this repair component as it impinges on the practical problems of human irradiation or exposure to actual or potential chemical mutagens and carcinogens. The significance of these studies lies in (i) the ubiquitousness of repair (most organisms, including man, have several complex repair systems), (ii) the belief that mutagenic and carcinogenic events may arise only from residual (nonrepaired) lesions or that error-prone repair systems may be the major induction mechanisms of the mutagenic or carcinogenic event, and (iii) the clear association of repair defects and highly carcinogenic disease states in man [xeroderma pigmentosum (XP)

  8. Augmented Automated Material Accounting Statistics System (AMASS)

    International Nuclear Information System (INIS)

    Lumb, R.F.; Messinger, M.; Tingey, F.H.

    1983-01-01

    This paper describes an extension of the AMASS methodology which was previously presented at the 1981 INMM annual meeting. The main thrust of the current effort is to develop procedures and a computer program for estimating the variance of an Inventory Difference when many sources of variability, other than measurement error, are admitted in the model. Procedures also are included for the estimation of the variances associated with measurement error estimates and their effect on the estimated limit of error of the inventory difference (LEID). The algorithm for the LEID measurement component uncertainty involves the propagated component measurement variance estimates as well as their associated degrees of freedom. The methodology and supporting computer software is referred to as the augmented Automated Material Accounting Statistics System (AMASS). Specifically, AMASS accommodates five source effects. These are: (1) measurement errors (2) known but unmeasured effects (3) measurement adjustment effects (4) unmeasured process hold-up effects (5) residual process variation A major result of this effort is a procedure for determining the effect of bias correction on LEID, properly taking into account all the covariances that exist. This paper briefly describes the basic models that are assumed; some of the estimation procedures consistent with the model; data requirements, emphasizing availability and other practical considerations; discusses implications for bias corrections; and concludes by briefly describing the supporting computer program

  9. Involvement of the DNA mismatch repair system in cisplatin sensitivity of testicular germ cell tumours.

    Science.gov (United States)

    Rudolph, Christiane; Melau, Cecilie; Nielsen, John E; Vile Jensen, Kristina; Liu, Dekang; Pena-Diaz, Javier; Rajpert-De Meyts, Ewa; Rasmussen, Lene Juel; Jørgensen, Anne

    2017-08-01

    Testicular germ cell tumours (TGCT) are highly sensitive to cisplatin-based chemotherapy, but patients with tumours containing differentiated teratoma components are less responsive to this treatment. The cisplatin sensitivity in TGCT has previously been linked to the embryonic phenotype in the majority of tumours, although the underlying mechanism largely remains to be elucidated. The aim of this study was to investigate the role of the DNA mismatch repair (MMR) system in the cisplatin sensitivity of TGCT. The expression pattern of key MMR proteins, including MSH2, MSH6, MLH1 and PMS2, were investigated during testis development and in the pathogenesis of TGCT, including germ cell neoplasia in situ (GCNIS). The TGCT-derived cell line NTera2 was differentiated using retinoic acid (10 μM, 6 days) after which MMR protein expression and activity, as well as cisplatin sensitivity, were investigated in both undifferentiated and differentiated cells. Finally, the expression of MSH2 was knocked down by siRNA in NTera2 cells after which the effect on cisplatin sensitivity was examined. MMR proteins were expressed in proliferating cells in the testes, while in malignant germ cells MMR protein expression was found to coincide with the expression of the pluripotency factor OCT4, with no or low expression in the more differentiated yolk sac tumours, choriocarcinomas and teratomas. In differentiated NTera2 cells we found a significantly (p cisplatin sensitivity, compared to undifferentiated NTera2 cells. Also, we found that partial knockdown of MSH2 expression in undifferentiated NTera2 cells resulted in a significantly (p cisplatin sensitivity. This study reports, for the first time, expression of the MMR system in fetal gonocytes, from which GCNIS cells are derived. Our findings in primary TGCT specimens and TGCT-derived cells suggest that a reduced sensitivity to cisplatin in differentiated TGCT components could result from a reduced expression of MMR proteins, in

  10. ARTIFICIAL NEURAL NETWORKS BASED GEARS MATERIAL SELECTION HYBRID INTELLIGENT SYSTEM

    Institute of Scientific and Technical Information of China (English)

    X.C. Li; W.X. Zhu; G. Chen; D.S. Mei; J. Zhang; K.M. Chen

    2003-01-01

    An artificial neural networks(ANNs) based gear material selection hybrid intelligent system is established by analyzing the individual advantages and weakness of expert system (ES) and ANNs and the applications in material select of them. The system mainly consists of tow parts: ES and ANNs. By being trained with much data samples,the back propagation (BP) ANN gets the knowledge of gear materials selection, and is able to inference according to user input. The system realizes the complementing of ANNs and ES. Using this system, engineers without materials selection experience can conveniently deal with gear materials selection.

  11. Materials science for solar energy conversion systems

    CERN Document Server

    Granqvist, CG

    1991-01-01

    Rapid advances in materials technology are creating many novel forms of coatings for energy efficient applications in solar energy. Insulating heat mirrors, selective absorbers, transparent insulation and fluorescent concentrators are already available commercially. Radiative cooling, electrochromic windows and polymeric light pipes hold promise for future development, while chemical and photochemical processes are being considered for energy storage. This book investigates new material advances as well as applications, costs, reliability and industrial production of existing materials. Each c

  12. Design of online testing system of material radiation resistance

    International Nuclear Information System (INIS)

    Wan Junsheng; He Shengping; Gao Xinjun

    2014-01-01

    The capability of radiation resistance is important for some material used in some specifically engineering fields. It is the same principal applied in all existing test system that compares the performance parameter after radiation to evaluate material radiation resistance. A kind of new technique on test system of material radiation resistance is put forward in this paper. Experimentation shows that the online test system for material radiation resistance works well and has an extending application outlook. (authors)

  13. Veritex(TM) Patches for Structural Repair and Re-Use, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Cornerstone Research Group, Inc. (CRG) proposes to develop a bonded composite patch repair and re-use system based on CRG's VeritexTM materials. VeritexTM is a...

  14. Development and applications of Bacillus subtilis test systems for mutagens, involving DNA-repair deficiency and suppressible auxotrophic mutations

    International Nuclear Information System (INIS)

    Tanooka, H.

    1977-01-01

    A mutagen-tester of Bacillus subtilis was constructed and tested with known carcinogens. The parental strain HA101 of Okubo and Yanagida carrying suppressible nonsense mutations in his and met genes was transformed to carry an excision-repair deficiency mutation. The constructed strain TKJ5211 showed a 20-30-fold higher sensitivity for His + reversion than the parental strain when treated with UV and UV-mimetic chemicals but unchanged mutation frequency with X-rays and methyl methanesulfonate. The tester strain was used in a spot test of 30 selected chemicals and also for testing with liver homogenate activation. The results showed an almost equivalent but somewhat broader detection spectrum than the Salmonella typhimurium TA100 system. Another test method used a pair of B. subtilis strains differing in their DNA-repair capacity, i.e. the most UV-sensitive mutant HJ-15 and a wild-type strain, to detect repair-dependent DNA damage produced by chemicals. Spores could be used in either test

  15. The Influence of Hepatitis C Virus Therapy on the DNA Base Excision Repair System of Peripheral Blood Mononuclear Cells.

    Science.gov (United States)

    Czarny, Piotr; Merecz-Sadowska, Anna; Majchrzak, Kinga; Jabłkowski, Maciej; Szemraj, Janusz; Śliwiński, Tomasz; Karwowski, Bolesław

    2017-07-01

    Hepatitis C virus (HCV) can infect extrahepatic tissues, including lymphocytes, creating reservoir of the virus. Moreover, HCV proteins can interact with DNA damage response proteins of infected cells. In this article we investigated the influence of the virus infection and a new ombitasvir/paritaprevir/ritonavir ± dasabuvir ± ribavirin (OBV/PTV/r ± DSV ± RBV) anti-HCV therapy on the PBMCs (peripheral blood mononuclear cells, mainly lymphocytes) DNA base excision repair (BER) system. BER protein activity was analyzed in the nuclear and mitochondrial extracts (NE and ME) of PBMC isolated from patients before and after therapy, and from subjects without HCV, using modeled double-strand DNA, with 2'-deoxyuridine substitution as the DNA damage. The NE and ME obtained from patients before therapy demonstrated lower efficacy of 2'-deoxyuridine removal and DNA repair polymerization than those of the control group or patients after therapy. Moreover, the extracts from the patients after therapy had similar activity to those from the control group. However, the efficacy of apurinic/apyrimidinic site excision in NE did not differ between the studied groups. We postulate that infection of lymphocytes by the HCV can lead to a decrease in the activity of BER enzymes. However, the use of novel therapy results in the improvement of glycosylase activity as well as the regeneration of endonuclease and other crucial repair enzymes.

  16. Refinement of Foam Backfill Technology for Expedient Airfield Damage Repair- Phase I: Laboratory Evaluation of Foam Materials

    Science.gov (United States)

    2016-11-01

    trend is expected, because the foam materials are primarily composed of the same compounds ; only minor differences in the formula- tions are present...process. Fracture of this nature may be expected during use of this material in the field. ERDC TR-16-16 33 Figure 22. Foam-iT! SLOW specimens...Slow were produced with flat bottoms. However, this material was fairly brittle, as indicated by the fracturing observed on one of the specimens shown

  17. Discrete event simulation methods applied to advanced importance measures of repairable components in multistate network flow systems

    International Nuclear Information System (INIS)

    Huseby, Arne B.; Natvig, Bent

    2013-01-01

    Discrete event models are frequently used in simulation studies to model and analyze pure jump processes. A discrete event model can be viewed as a system consisting of a collection of stochastic processes, where the states of the individual processes change as results of various kinds of events occurring at random points of time. We always assume that each event only affects one of the processes. Between these events the states of the processes are considered to be constant. In the present paper we use discrete event simulation in order to analyze a multistate network flow system of repairable components. In order to study how the different components contribute to the system, it is necessary to describe the often complicated interaction between component processes and processes at the system level. While analytical considerations may throw some light on this, a simulation study often allows the analyst to explore more details. By producing stable curve estimates for the development of the various processes, one gets a much better insight in how such systems develop over time. These methods are particulary useful in the study of advanced importancez measures of repairable components. Such measures can be very complicated, and thus impossible to calculate analytically. By using discrete event simulations, however, this can be done in a very natural and intuitive way. In particular significant differences between the Barlow–Proschan measure and the Natvig measure in multistate network flow systems can be explored

  18. Multiobjective optimization of availability and cost in repairable systems design via genetic algorithms and discrete event simulation

    Directory of Open Access Journals (Sweden)

    Isis Didier Lins

    2009-04-01

    Full Text Available This paper attempts to provide a more realistic approach to the characterization of system reliability when handling redundancy allocation problems: it considers repairable series-parallel systems comprised of components subjected to corrective maintenance actions with failure-repair cycles modeled by renewal processes. A multiobjective optimization approach is applied since increasing the number of redundancies not only enlarges system reliability but also its associated costs. Then a multiobjective genetic algorithm is coupled with discrete event simulation and its solutions present the compromise between system reliability and cost. Two examples are provided. In the first one, the proposed algorithm is validated by comparison with results obtained from a system devised as to allow for analytical solutions of the objective functions. The second case analyzes a repairable system subjected to perfect repairs. Results from both examples show that the proposed method can be a valuable tool for the decision maker when choosing the system design.Esse artigo utiliza uma abordagem mais realista para a caracterização da confiabilidade de sistemas em problemas de alocação de redundâncias: são considerados sistemas série-paralelo formados por componentes sujeitos a ações de manutenção corretiva com ciclos de falha-reparo modelados por processos de renovação. É aplicada uma abordagem de otimização multiobjetivo, pois o aumento de redundâncias eleva a confiabilidade do sistema e também os seus custos. Assim, um algoritmo genético multiobjetivo é integrado com simulação discreta de eventos e suas soluções apresentam o compromisso entre confiabilidade e custo do sistema. Dois exemplos são fornecidos. No primeiro, o algoritmo proposto é validado através da comparação com resultados obtidos de um sistema criado de forma a permitir soluções analíticas das funções-objetivo. No segundo, analisa-se um sistema reparável sujeito a

  19. Chapter 8: Materials for Exploration Systems

    Science.gov (United States)

    Curreri, Peter A.

    2017-01-01

    Materials science and processing research in space can be thought of as a field of study that began with the sounding rocket experiments in the 1950s. Material science studies of the lunar surface materials returned during the Apollo missions enabled the study of lunar resource utilization. The study of materials science and processing in space continued with over 30 years of microgravity materials processing research which continues today in the International Space Station. These studies are the technical foundation that could enable lower cost human exploration through the use of in-situ propellant production, the production of energy from space resources, and the eventual establishment of a substantial portion of humanity living self sufficiently off Earth.

  20. Optimal interface between principal deterrent systems and material accounting

    International Nuclear Information System (INIS)

    Deiermann, P.J.; Opelka, J.H.

    1983-01-01

    The purpose of this study is to find an optimal blend between three safeguards systems for special nuclear material (SNM), the material accounting system and the physical security and material control systems. The latter two are denoted as principal deterrent systems. The optimization methodology employed is a two-stage decision algorithm, first an explicit maximization of expected diverter benefits and subsequently a minimization of expected defender costs for changes in material accounting procedures and incremental improvements in the principal deterrent systems. The probability of diverter success function dependent upon the principal deterrents and material accounting system variables is developed. Within the range of certainty of the model, existing material accounting, material control and physical security practices are justified

  1. A simulation model for material accounting systems

    International Nuclear Information System (INIS)

    Coulter, C.A.; Thomas, K.E.

    1987-01-01

    A general-purpose model that was developed to simulate the operation of a chemical processing facility for nuclear materials has been extended to describe material measurement and accounting procedures as well. The model now provides descriptors for material balance areas, a large class of measurement instrument types and their associated measurement errors for various classes of materials, the measurement instruments themselves with their individual calibration schedules, and material balance closures. Delayed receipt of measurement results (as for off-line analytical chemistry assay), with interim use of a provisional measurement value, can be accurately represented. The simulation model can be used to estimate inventory difference variances for processing areas that do not operate at steady state, to evaluate the timeliness of measurement information, to determine process impacts of measurement requirements, and to evaluate the effectiveness of diversion-detection algorithms. Such information is usually difficult to obtain by other means. Use of the measurement simulation model is illustrated by applying it to estimate inventory difference variances for two material balance area structures of a fictitious nuclear material processing line

  2. Storage and processing system for fissile materials

    International Nuclear Information System (INIS)

    Bubowskij, B.G.; Bogatyrew, W.K.; Wladykow, G.M.; Swiridenko, W.J.

    1976-01-01

    The invention concerns the construction of a radiation protection wall by which the reflection of neutrons in a container arranged in the vicinity of the wall is reduced. The radiation protection wall has a coating of neutron-retarding material on top of which there is a layer of neutron absorbing material, the former having a surface structured with regular projections and recesses spaced at 1/8 to 3 neutron ranges. The recesses may be filled with porous material or take up neutron radiation detectors. Other construction features are described. (UWI) [de

  3. Nuclear material measurement system in Brazil

    International Nuclear Information System (INIS)

    Almeida, S.G. de.

    1988-01-01

    The description of the activities developed at the Safeguards Laboratory of Brazilian Nuclear Energy Commission is done. The methods and techniques used for measuring and evaluating nuclear materials and facilities are presented. (E.G.) [pt

  4. Electrode materials and lithium battery systems

    Science.gov (United States)

    Amine, Khalil [Downers Grove, IL; Belharouak, Ilias [Westmont, IL; Liu, Jun [Naperville, IL

    2011-06-28

    A material comprising a lithium titanate comprising a plurality of primary particles and secondary particles, wherein the average primary particle size is about 1 nm to about 500 nm and the average secondary particle size is about 1 .mu.m to about 4 .mu.m. In some embodiments the lithium titanate is carbon-coated. Also provided are methods of preparing lithium titanates, and devices using such materials.

  5. Molecular dialogues between the ischemic brain and the peripheral immune system: Dualistic roles in injury and repair

    Science.gov (United States)

    An, Chengrui; Shi, Yejie; Li, Peiying; Hu, Xiaoming; Gan, Yu; Stetler, Ruth A.; Leak, Rehana K.; Gao, Yanqin; Sun, Bao-Liang; Zheng, Ping; Chen, Jun

    2014-01-01

    Immune and inflammatory responses actively modulate the pathophysiological processes of acute brain injuries such as stroke. Soon after the onset of stroke, signals such as brain-derived antigens, danger-associated molecular patterns (DAMPs), cytokines, and chemokines are released from the injured brain into the systemic circulation. The injured brain also communicates with peripheral organs through the parasympathetic and sympathetic branches of the autonomic nervous system. Many of these diverse signals not only activate resident immune cells in the brain, but also trigger robust immune responses in the periphery. Peripheral immune cells then migrate toward the site of injury and release additional cytokines, chemokines, and other molecules, causing further disruptive or protective effects in the ischemic brain. Bidirectional communication between the injured brain and the peripheral immune system is now known to regulate the progression of stroke pathology as well as tissue repair. In the end, this exquisitely coordinated crosstalk helps determine the fate of animals after stroke. This article reviews the literature on ischemic brain-derived signals through which peripheral immune responses are triggered, and the potential impact of these peripheral responses on brain injury and repair. Pharmacological strategies and cell-based therapies that target the dialogue between the brain and peripheral immune system show promise as potential novel treatments for stroke. PMID:24374228

  6. Molecular dialogs between the ischemic brain and the peripheral immune system: dualistic roles in injury and repair.

    Science.gov (United States)

    An, Chengrui; Shi, Yejie; Li, Peiying; Hu, Xiaoming; Gan, Yu; Stetler, Ruth A; Leak, Rehana K; Gao, Yanqin; Sun, Bao-Liang; Zheng, Ping; Chen, Jun

    2014-04-01

    Immune and inflammatory responses actively modulate the pathophysiological processes of acute brain injuries such as stroke. Soon after the onset of stroke, signals such as brain-derived antigens, danger-associated molecular patterns (DAMPs), cytokines, and chemokines are released from the injured brain into the systemic circulation. The injured brain also communicates with peripheral organs through the parasympathetic and sympathetic branches of the autonomic nervous system. Many of these diverse signals not only activate resident immune cells in the brain, but also trigger robust immune responses in the periphery. Peripheral immune cells then migrate toward the site of injury and release additional cytokines, chemokines, and other molecules, causing further disruptive or protective effects in the ischemic brain. Bidirectional communication between the injured brain and the peripheral immune system is now known to regulate the progression of stroke pathology as well as tissue repair. In the end, this exquisitely coordinated crosstalk helps determine the fate of animals after stroke. This article reviews the literature on ischemic brain-derived signals through which peripheral immune responses are triggered, and the potential impact of these peripheral responses on brain injury and repair. Pharmacological strategies and cell-based therapies that target the dialog between the brain and peripheral immune system show promise as potential novel treatments for stroke. Published by Elsevier Ltd.

  7. Material control test and evaluation system at the ICPP

    International Nuclear Information System (INIS)

    Johnson, C.E.

    1979-01-01

    The US DOE is evaluating process monitoring as part of a total nuclear material safeguards system. A monitoring system is being installed at the Idaho Chemical Processing Plant to test and evaluate material control and surveillance concepts in an operating nuclear fuel reprocessing plant. Process monitoring for nuclear material control complements conventional safeguards accountability and physical protection to assure adherence to approved safeguards procedures and verify containment of nuclear materials within the processing plant

  8. Clinical Outcomes and Complications of Percutaneous Achilles Repair System Versus Open Technique for Acute Achilles Tendon Ruptures.

    Science.gov (United States)

    Hsu, Andrew R; Jones, Carroll P; Cohen, Bruce E; Davis, W Hodges; Ellington, J Kent; Anderson, Robert B

    2015-11-01

    Limited incision techniques for acute Achilles tendon ruptures have been developed in recent years to improve recovery and reduce postoperative complications compared with traditional open repair. The purpose of this retrospective cohort study was to analyze the clinical outcomes and postoperative complications between acute Achilles tendon ruptures treated using a percutaneous Achilles repair system (PARS [Arthrex, Inc, Naples, FL]) versus open repair and evaluate the overall outcomes for operatively treated Achilles ruptures. Between 2005 and 2014, 270 consecutive cases of operatively treated acute Achilles tendon ruptures were reviewed (101 PARS, 169 open). Patients with Achilles tendinopathy, insertional ruptures, chronic tears, or less than 3-month follow-up were excluded. Operative treatment consisted of a percutaneous technique (PARS) using a 2-cm transverse incision with FiberWire (Arthrex, Inc, Naples, FL) sutures or open repair using a 5- to 8-cm posteromedial incision with FiberWire in a Krackow fashion reinforced with absorbable sutures. Patient demographics were recorded along with medical comorbidities, activity at injury, time from injury to surgery, length of follow-up, return to baseline activities by 5 months, and postoperative complications. The most common activity during injury for both groups was basketball (PARS: 39%, open: 47%). A greater number of patients treated with PARS were able to return to baseline physical activities by 5 months compared with the open group (PARS: 98%, open: 82%; P = .0001). There were no significant differences (P > .05) between groups in rates of rerupture (P = 1.0), sural neuritis (P = .16), wound dehiscence (P = .74), superficial (P = .29) and/or deep infection (P = .29), or reoperation (P = .13). There were no deep vein thromboses (DVTs) or reruptures in either group. In the PARS group, there were no cases of sural neuritis, 3 cases (3%) of superficial wound dehiscence, and 2 reoperations (2%) for superficial

  9. Technology assessment of solar-energy systems. Materials resource and hazardous materials impacts of solar deployment

    Science.gov (United States)

    Schiffman, Y. M.; Tahami, J. E.

    1982-04-01

    The materials-resource and hazardous-materials impacts were determined by examining the type and quantity of materials used in the manufacture, construction, installation, operation and maintenance of solar systems. The materials requirements were compared with US materials supply and demand data to determine if potential problems exist in terms of future availability of domestic supply and increased dependence on foreign sources of supply. Hazardous materials were evaluated in terms of public and occupational health hazards and explosive and fire hazards. It is concluded that: although large amounts of materials would be required, the US had sufficient industrial capacity to produce those materials; (2) postulated growth in solar technology deployment during the period 1995-2000 could cause some production shortfalls in the steel and copper industry; the U.S. could increase its import reliance for certain materials such as silver, iron ore, and copper; however, shifts to other materials such as aluminum and polyvinylchloride could alleviate some of these problems.

  10. Repair in Mourao power plant spillway: application of recycled material concrete admixtures - stage one; Reparos no vertedouro da UHE Mourao: aplicacao de concretos com adicao de material reciclado - 1a. parte

    Energy Technology Data Exchange (ETDEWEB)

    Galvao, Jose Carlos Alves; Portella, Kleber Franke; Joukoski, Alex; Mendes, Roberto [Instituto de Tecnologia para o Desenvolvimento (LACTEC), Curitiba, PR (Brazil)], Emails: jose.galvao@lactec.org.br, portella@lactec.org.br, alex@lactec.org.br; roberto.mendes@lactec.org.br; Ferreira, Elizeu Santos [Companhia Paranaense de Energia (COPEL), Curitiba, PR (Brazil)], Email: elizeu.sf@copel.com

    2009-10-15

    The Mourao hydroelectric power plant located in the city of Campo Mourao, in the state of Parana, southern region of Brazil, was inaugurated in 1964, with 7500 kW of installed power. Defects in the spillway surface of the dam had been identified throughout the time. With the purpose of recovering the concrete hydraulic surface, repair materials were proposed in this paper, considering technology development and environment conservation. Concrete mixtures containing recycled materials - low-density polyethylene (LDPE), polyethylene terephthalate (PET) and waste tires - had its performance tested in laboratory. Mechanical properties, such as compressive strength, tensile strength and adherence were evaluated using cylindrical concrete specimens. Results were appraised and the best compositions were selected to be tested on spillway surface of Mourao dam. (author)

  11. Development of total medical material distribution management system.

    Science.gov (United States)

    Uto, Y; Kumamoto, I

    1994-07-01

    Since September 1992, attempts have been made at Kagoshima University Hospital to develop the Medical Material Distribution Management System which helps to realize optimal hospital management as a subsystem of the Total Hospital Information System of Kagoshima University (THINK). As this system has been established, it has become possible for us to have an accurate grasp of the flow and stock of medical materials at our hospital. Furthermore, since September 1993, the Medical Material Distribution Management System has been improved and the Total Medical Material Distribution Management System has been smoothly introduced into the site of clinical practice. This system enables automatic demands for fees for treatment with specific instruments and materials covered by health insurance. It was difficult to predict the effect of this system, because no similar system had been developed in Japan. However, more satisfactory results than expected have been obtained since its introduction.

  12. Materials And Processes Technical Information System (MAPTIS) LDEF materials data base

    Science.gov (United States)

    Funk, Joan G.; Strickland, John W.; Davis, John M.

    1993-01-01

    A preliminary Long Duration Exposure Facility (LDEF) Materials Data Base was developed by the LDEF Materials Special Investigation Group (MSIG). The LDEF Materials Data Base is envisioned to eventually contain the wide variety and vast quantity of materials data generated from LDEF. The data is searchable by optical, thermal, and mechanical properties, exposure parameters (such as atomic oxygen flux) and author(s) or principal investigator(s). Tne LDEF Materials Data Base was incorporated into the Materials and Processes Technical Information System (MAPTIS). MAPTIS is a collection of materials data which has been computerized and is available to engineers, designers, and researchers in the aerospace community involved in the design and development of spacecraft and related hardware. The LDEF Materials Data Base is described and step-by-step example searches using the data base are included. Information on how to become an authorized user of the system is included.

  13. Application of Rapid Prototyping Technique and Intraoperative Navigation System for the Repair and Reconstruction of Orbital Wall Fractures

    Science.gov (United States)

    Cha, Jong Hyun; Lee, Yong Hae; Ruy, Wan Chul; Roe, Young; Moon, Myung Ho

    2016-01-01

    Background Restoring the orbital cavity in large blow out fractures is a challenge for surgeons due to the anatomical complexity. This study evaluated the clinical outcomes and orbital volume after orbital wall fracture repair using a rapid prototyping (RP) technique and intraoperative navigation system. Methods This prospective study was conducted on the medical records and radiology records of 12 patients who had undergone a unilateral blow out fracture reconstruction using a RP technique and an intraoperative navigation system from November 2014 to March 2015. The surgical results were assessed by an ophthalmic examination and a comparison of the preoperative and postoperative orbital volume ratio (OVR) values. Results All patients had a successful treatment outcome without complications. Volumetric analysis revealed a significant decrease in the mean OVR from 1.0952±0.0662 (ranging from 0.9917 to 1.2509) preoperatively to 0.9942±0.0427 (ranging from 0.9394 to 1.0680) postoperatively. Conclusion The application of a RP technique for the repair of orbital wall fractures is a useful tool that may help improve the clinical outcomes by understanding the individual anatomy, determining the operability, and restoring the orbital cavity volume through optimal implant positioning along with an intraoperative navigation system. PMID:28913272

  14. Bioinspired Infrared Sensing Materials and Systems.

    Science.gov (United States)

    Shen, Qingchen; Luo, Zhen; Ma, Shuai; Tao, Peng; Song, Chengyi; Wu, Jianbo; Shang, Wen; Deng, Tao

    2018-05-11

    Bioinspired engineering offers a promising alternative approach in accelerating the development of many man-made systems. Next-generation infrared (IR) sensing systems can also benefit from such nature-inspired approach. The inherent compact and uncooled operation of biological IR sensing systems provides ample inspiration for the engineering of portable and high-performance artificial IR sensing systems. This review overviews the current understanding of the biological IR sensing systems, most of which are thermal-based IR sensors that rely on either bolometer-like or photomechanic sensing mechanism. The existing efforts inspired by the biological IR sensing systems and possible future bioinspired approaches in the development of new IR sensing systems are also discussed in the review. Besides these biological IR sensing systems, other biological systems that do not have IR sensing capabilities but can help advance the development of engineered IR sensing systems are also discussed, and the related engineering efforts are overviewed as well. Further efforts in understanding the biological IR sensing systems, the learning from the integration of multifunction in biological systems, and the reduction of barriers to maximize the multidiscipline collaborations are needed to move this research field forward. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Computerized real-time materials accountability system for safeguards material control

    International Nuclear Information System (INIS)

    Spencer, W.F.; Affel, R.G.; Austin, H.C.; Nichols, J.P.; Stoutt, B.H.; Wachter, J.W.

    1975-01-01

    A real-time, computer-based system is described which provides safeguards material control at the Oak Ridge National Laboratory. Originally installed in 1972 to provide computerized real-time fissile materials accountability for criticality control purposes, the system has been expanded to provide accountability of all source and nuclear materials (SNM) and to utilize the on-line inventory files in support of the Laboratory physical protection and surveillance procedures. (auth)

  16. Status Report on Structural Materials for Advanced Nuclear Systems

    International Nuclear Information System (INIS)

    Allen, T.R.; Balbaud-Celerier, F.; Asayama, T.; Pouchon, M.; Busby, J.T.; Maloy, S.; Park, J.Y.; Fazio, C.; Dai, Y.; Agostini, P.; Chevalier, J.P.; Marrow, J.

    2013-01-01

    Materials performance is critical to the safe and economic operation of any nuclear system. As the international community pursues the development of Generation IV reactor concepts and accelerator-driven transmutation systems, it will be increasingly necessary to develop advanced materials capable of tolerating the more challenging environments of these new systems. The international community supports numerous materials research programmes, with each country determining its individual focus on a case-by-case basis. In many instances, similar alloys of materials systems are being studied in several countries, providing the opportunity for collaborative and cross-cutting research that benefits different systems. This report is a snapshot of the current materials programmes supporting the development of advanced concepts. The descriptions of the research are grouped by concept, and national programmes are described within each concept. The report provides an overall sense of the importance of materials research worldwide and the opportunities for synergy among the countries represented in this overview. (authors)

  17. Meningocele repair

    Science.gov (United States)

    ... is surgery to repair birth defects of the spine and spinal membranes. Meningocele and myelomeningocele ... is covered by a sterile dressing. Your child may then be transferred to a neonatal intensive ...

  18. Intelligent Materials Tracking System for Construction Projects Management

    Directory of Open Access Journals (Sweden)

    Narimah Kasim

    2015-05-01

    Full Text Available An essential factor adversely affecting the performance of construction projects is the improper handling of materials during site activities. In addition, paper-based reports are mostly used to record and exchange information related to the material components within the supply chain, which is problematic and inefficient. Generally, technologies (such as wireless systems and RFID are not being adequately used to overcome human errors and are not well integrated with project management systems to make tracking and management of materials easier and faster. Findings from a literature review and surveys showed that there is a lack of positive examples of such tools having been used effectively. Therefore, this research focused on the development of a materials tracking system that integrates RFID-based materials management with resources modelling to improve on-site materials tracking. Rapid prototyping was used to develop the system and testing of the system was carried out to examine the functionality and working appropriately. The proposed system is intended to promote the employment of RFID for automatic materials tracking with integration of resource modelling (Microsoft (R Office Project in the project management system in order to establish which of the tagged components are required resources for certain project tasks. In conclusion, the system provides an automatic and easy tracking method for managing materials during materials delivery and inventory management processes in construction projects.

  19. Automated material accounting statistics system (AMASS)

    International Nuclear Information System (INIS)

    Messinger, M.; Lumb, R.F.; Tingey, F.H.

    1981-01-01

    In this paper the modeling and statistical analysis of measurement and process data for nuclear material accountability is readdressed under a more general framework than that provided in the literature. The result of this effort is a computer program (AMASS) which uses the algorithms and equations of this paper to accomplish the analyses indicated. The actual application of the method to process data is emphasized

  20. Incorrect modeling of the failure process of minimally repaired systems under random conditions: The effect on the maintenance costs

    International Nuclear Information System (INIS)

    Pulcini, Gianpaolo

    2015-01-01

    This note investigates the effect of the incorrect modeling of the failure process of minimally repaired systems that operates under random environmental conditions on the costs of a periodic replacement maintenance. The motivation of this paper is given by a recently published paper, where a wrong formulation of the expected cost for unit time under a periodic replacement policy is obtained. This wrong formulation is due to the incorrect assumption that the intensity function of minimally repaired systems that operate under random conditions has the same functional form as the failure rate of the first failure time. This produced an incorrect optimization of the replacement maintenance. Thus, in this note the conceptual differences between the intensity function and the failure rate of the first failure time are first highlighted. Then, the correct expressions of the expected cost and of the optimal replacement period are provided. Finally, a real application is used to measure how severe can be the economical consequences caused by the incorrect modeling of the failure process.

  1. Workshop on materials control and accounting system design

    International Nuclear Information System (INIS)

    Pillay, K.K.S.

    1989-01-01

    The chapter describes the workshop aimed at reinforcing, through participation in the design exercise, the concepts of nuclear materials control and accountability. Topics include: workshop format; key elements of a materials management and accounting (MC and A) system; and MC and A system design including safeguards organization and management, material access areas, key measurement points, nuclear materials measurements, physical inventory, material balance closings, and internal controls. Appended to this chapter is a detailed description of a facility that produces metallic plutonium and the safeguards requirements for this facility

  2. [Research of repairing rabbit knee joint cartilage defect by compound material of fibrin glue and decalcified bone matrix (DBM) and chondrocytes].

    Science.gov (United States)

    He, Jie; Yang, Xiang; Yue, Peng-ju; Wang, Guan-yu; Guo, Ting; Zhao, Jian-ning

    2009-07-01

    To investigate the feasibility and effectivity of using compound material of fibrin glue and DBM as scaffolds for cartilage tissue engineering. Chondrocytes isolated from articular cartilage were seeded into prepared scaffolds, after incubation for 4 weeks in vitro. Chondrocytes and fibrin glue and DBM constructs were implanted in the joint cave of rabbit. The specimens were excised at the 4th, 8th, 12th week, examined grossly analyzed by haematoxylin cosine, toluidine blues staining and type II collagen immunohistochemistry reaction. Wakitani score was counted to evaluate the repairing effect. Grossly analysis showed some ivory tissue filled the caves after 4 weeks and the caves were full filled with smooth surface after 12 weeks. The microscope showed a good deal of chondrocytes appeared after 8 weeks and more type II collagen than 4 weeks. Twelve weeks later, cartilage lacuna could be observed. The cells arrangement and the amount of type II collagen both showed the same as the natural one. Complicated material of fibrin glue and DBM as scaffolds can be used as scaffolds for cartilage tissue engineering.

  3. Endovascular repair of arterial iliac vessel wall lesions with a self-expandable nitinol stent graft system.

    Directory of Open Access Journals (Sweden)

    Birger Mensel

    Full Text Available To assess the therapeutic outcome after endovascular repair of iliac arterial lesions (IALs using a self-expandable Nitinol stent graft system.Between July 2006 and March 2013, 16 patients (13 males, mean age: 68 years with a self-expandable Nitinol stent graft. A total of 19 lesions were treated: nine true aneurysms, two anastomotic aneurysms, two dissections, one arteriovenous fistula, two type 1B endoleaks after endovascular aneurysm repair, one pseudoaneurysm, and two perforations after angioplasty. Pre-, intra-, and postinterventional imaging studies and the medical records were analyzed for technical and clinical success and postinterventional complications.The primary technical and clinical success rate was 81.3% (13/16 patients and 75.0% (12/16, respectively. Two patients had technical failure due to persistent type 1A endoleak and another patient due to acute stent graft thrombosis. One patient showed severe stent graft kinking on the first postinterventional day. In two patients, a second intervention was performed. The secondary technical and clinical success rate was 87.5% (14/16 and 93.8% (15/16. The minor complication rate was 6.3% (patient with painful hematoma at the access site. The major complication rate was 6.3% (patient with ipsilateral deep vein thrombosis. During median follow-up of 22.4 months, an infection of the aneurysm sac in one patient and a stent graft thrombosis in another patient were observed.Endovascular repair of various IALs with a self-expandable Nitinol stent graft is safe and effective.

  4. 30 CFR 56.6801 - Vehicle repair.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Vehicle repair. 56.6801 Section 56.6801 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Vehicle repair. Vehicles containing explosive material and oxidizers shall not be taken into a repair...

  5. Accounting systems for special nuclear material control. Technical report

    International Nuclear Information System (INIS)

    Korstad, P.A.

    1980-05-01

    Nuclear material accounting systems were examined and compared to financial double-entry accounting systems. Effective nuclear material accounting systems have been designed using the principles of double-entry financial accounting. The modified double-entry systems presently employed are acceptable if they provide adequate control over the recording and summarizing of transactions. Strong internal controls, based on principles of financial accounting, can help protect nuclear materials and produce accurate, reliable accounting data. An electronic data processing system can more accurately maintain large volumes of data and provide management with more current, reliable information

  6. AREA 2: Novel Materials for Robust Repair of Leaky Wellbores in CO2 Storage Formations

    Energy Technology Data Exchange (ETDEWEB)

    Balhoff, Matthew [Univ. of Texas, Austin, TX (United States); Tavassoli, Shayan [Univ. of Texas, Austin, TX (United States); Fei Ho, Jostine [Univ. of Texas, Austin, TX (United States)

    2016-01-31

    The potential leakage of hydrocarbon fluids or CO2 out of subsurface formations through wells with fractured cement or debonded microannuli is a primary concern in oil and gas production and CO2 storage. The presence of fractures in a cement annulus with apertures on the order of 10–300 microns can pose a significant leakage danger with effective permeability in the range of 0.1–1 mD (millidarcy). Leakage pathways with small apertures are often difficult to repair using conventional oilfield cement, thus a low-viscosity sealant that can be easily placed into these fractures while providing an effective seal is desired. The development of a novel application using pH-triggered polymeric sealants could potentially be the solution to plugging these fractures and that was the research aim of this study. The application is based on the transport and reaction of a low-pH poly(acrylic acid) polymer through fractures in strongly alkaline cement. The pH-sensitive microgels viscosify upon neutralization with cement to become highly swollen gels with substantial yield stress that can block fluid flow. Experiments in a cement fracture determined the effects of the viscosification and gel deposition via real-time visual observation and measurements of pressure gradient and effluent pH. While the pH-triggered gelling mechanism and rheology measurements of the neutralized polymer gel show promising results, the polymer solution in contact with cement undergoes an undesirable reaction known as polymer syneresis. Syneresis is caused by the release of calcium cation from cement that collapses the polymer network. Syneresis produces an unstable calcium-precipitation byproduct that is detrimental to the strength and stability of the gel in place. As a result, gel-sealed leakage pathways that subjected to various degrees of syneresis often failed to hold back pressures. Several chemicals were studied to inhibit polymer syneresis and tested for pretreatment of

  7. Management review of nuclear material control and accounting systems

    International Nuclear Information System (INIS)

    1975-06-01

    Section 70.58, ''Fundamental Nuclear Material Controls,'' of 10 CFR Part 70, ''Special Nuclear Materials,'' requires, in paragraph 70.58(c), that certain licensees authorized to possess more than one effective kilogram of special nuclear material establish a management system to provide for the development, revision, implementation, and enforcement of nuclear material control and accounting procedures. Such a system must provide for a review of the nuclear material control system at least every 12 months. This guide describes the purpose and scope, personnel qualifications, depth of detail, and procedures that are acceptable to the NRC staff for the management review of nuclear material control systems required under paragraph 70.58(c) of 10 CFR Part 70. (U.S.)

  8. Clamp wins pipe repair prize

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2001-04-01

    This paper describes the permanent pipeline repair system, developed by Tekmar, which is powered by seawater hydraulics and is easily installed and tested by any workclass remotely operated vehicle (rov). Details are given of the two main components of the system, namely, the diverless high pressure split repair clamp and the rov-operated tool to install it.

  9. Hungarian national nuclear material control and accounting system

    International Nuclear Information System (INIS)

    Lendvai, O.

    1985-01-01

    The Hungarian system for nuclear materials control and accounting is briefly described. Sections include a historical overview, a description of nuclear activities and an outline of the organizational structure of the materials management system. Subsequent sections discuss accounting, verification and international relations

  10. Smart Materials Systems Through Mesoscale Patterning

    National Research Council Canada - National Science Library

    Aksay, Ilhan

    2001-01-01

    ...) self-assembled monolayers, and (3) 3-dimensional co-assembly. The two novel systems developed for use in sensor and actuator technologies were piezoelectric shell transducers and 1-3 piezocomposite hydrophones...

  11. Corrosion behaviour of materials selected for FMIT lithium system

    Energy Technology Data Exchange (ETDEWEB)

    Bazinet, G.D.; Brehm, W.F.

    1983-09-01

    The corrosion behavior of selected materials in a liquid lithium environment was studied in support of system and component designs for the Fusion Materials Irradiation Test (FMIT) Facility. Testing conditions ranged from about 3700 to about6500 hours of exposure to flowing lithium at temperatures from 230/sup 0/ to 270/sup 0/C and static lithium at temperatures from 200/sup 0/ to 500/sup 0/C. Principal areas of investigation included lithium corrosion/erosion effects on FMIT lithium system baseline and candidate materials. Material coupons and full-size prototypic components were evaluated to determine corrosion rates, fatigue crack growth rates, structural compatibility, and component acceptability for the lithium system. Based on the results of these studies, concerns regarding system materials and component designs were satisfactorily resolved to support a 20-year design life requirement for the FMIT lithium system.

  12. Corrosion behaviour of materials selected for FMIT lithium system

    International Nuclear Information System (INIS)

    Bazinet, G.D.; Brehm, W.F.

    1983-01-01

    The corrosion behavior of selected materials in a liquid lithium environment was studied in support of system and component designs for the Fusion Materials Irradiation Test (FMIT) Facility. Testing conditions ranged from about 3700 to about6500 hours of exposure to flowing lithium at temperatures from 230 0 to 270 0 C and static lithium at temperatures from 200 0 to 500 0 C. Principal areas of investigation included lithium corrosion/erosion effects on FMIT lithium system baseline and candidate materials. Material coupons and full-size prototypic components were evaluated to determine corrosion rates, fatigue crack growth rates, structural compatibility, and component acceptability for the lithium system. Based on the results of these studies, concerns regarding system materials and component designs were satisfactorily resolved to support a 20-year design life requirement for the FMIT lithium system

  13. System to detect nuclear materials by active neutron method

    International Nuclear Information System (INIS)

    Koroev, M.; Korolev, Yu.; Lopatin, Yu.; Filonov, V.

    1999-01-01

    The report presents the results of the development of the system to detect nuclear materials by active neutron method measuring delayed neutrons. As the neutron source the neutron generator was used. The neutron generator was controlled by the system. The detectors were developed on the base of the helium-3 counters. Each detector consist of 6 counters. Using a number of such detectors it is possible to verify materials stored in different geometry. There is an spectrometric scintillator detector in the system which gives an additional functional ability to the system. The system could be used to estimate the nuclear materials in waste, to detect the unauthorized transfer of the nuclear materials, to estimate the material in tubes [ru

  14. DNA repair

    International Nuclear Information System (INIS)

    Van Zeeland, A.A.

    1984-01-01

    In this chapter a series of DNA repair pathways are discussed which are available to the cell to cope with the problem of DNA damaged by chemical or physical agents. In the case of microorganisms our knowledge about the precise mechanism of each DNA repair pathway and the regulation of it has been improved considerably when mutants deficient in these repair mechanisms became available. In the case of mammalian cells in culture, until recently there were very little repair deficient mutants available, because in almost all mammalian cells in culture at least the diploid number of chromosomes is present. Therefore the frequency of repair deficient mutants in such populations is very low. Nevertheless because replica plating techniques are improving some mutants from Chinese hamsters ovary cells and L5178Y mouse lymphoma cells are now available. In the case of human cells, cultures obtained from patients with certain genetic diseases are available. A number of cells appear to be sensitive to some chemical or physical mutagens. These include cells from patients suffering from xeroderma pigmentosum, Ataxia telangiectasia, Fanconi's anemia, Cockayne's syndrome. However, only in the case of xeroderma pigmentosum cells, has the sensitivity to ultraviolet light been clearly correlated with a deficiency in excision repair of pyrimidine dimers. Furthermore the work with strains obtained from biopsies from man is difficult because these cells generally have low cloning efficiencies and also have a limited lifespan in vitro. It is therefore very important that more repair deficient mutants will become available from established cell lines from human or animal origin

  15. The system of nuclear material control of Kazakhstan

    International Nuclear Information System (INIS)

    Yeligbayeva, G.Zh.

    2001-01-01

    Full text: The State system for nuclear material control consists of three integral components. The efficiency of each is to guarantee the non-proliferation regime in Kazakhstan. The components are the following: accounting, export and import control and physical protection of nuclear materials. First, the implementation of the goals of accounting and control bring into force, by the organization of the system for accounting and measurement of nuclear materials to determine present quantity. Organizing the accounting for nuclear material at facilities will ensure the efficiency of accountancy and reporting information. This defines the effectiveness of the state system for the accounting for the Kazakhstan's nuclear materials. Currently, Kazakhstan's nuclear material is fully safeguarded in designated secure locations. Kazakhstan has a nuclear power plant, 4 research reactors and a fuel fabrication plant. The governmental information system for nuclear materials control consist of two level: Governmental level - KAEA collects reports from facilities and prepares the reports for International Atomic Energy Agency, keeping of supporting documents and other necessary information, a data base of export and import, a data base of nuclear material inventory. Facility level - registration and processing information from key measurement points, formation the facility's nuclear materials accounting database. All facilities have computerized systems. Currently, all facilities are safeguarded under IAEA safeguarding standards, through IAEA inspections. Annually, IAEA verifies all nuclear materials at all Kazakhstan nuclear facilities. The government reporting system discloses the existence of all nuclear material and its transfer intended for interaction through the export control system and the nuclear control accounting system. Nuclear material export is regulated by the regulations of the Nuclear Export Control Law. The standard operating procedure is the primary means for

  16. The effect of gamma-ray and ethylene oxide sterilization on collagen-based wound-repair materials

    International Nuclear Information System (INIS)

    Gorham, S.D.; Scott, R.

    1993-01-01

    The effects of 2.5, 5.0, 7.5 and 10 Mrad gamma-irradiation and ethylene oxide sterilization on collagen-coated vicryl mesh, on collagen film and vicryl mesh were investigated. No cytotoxic effects were observed towards either L929 cells or human fibroblasts with any of the treatments, even at the highest doses of irradiation. Although the rate of biodegradation and tissue reaction towards the test materials appeared to be relatively unaffected by ethylene oxide, the rate of breakdown in the lumbar muscles of laboratory rats was considerably increased by irradiation. Dose-dependent irradiation damage to the vicryl mesh was confirmed in vitro using viscometry and by an increase in the rate of hydrolysis in phosphate-buffered saline (PBS) at 37 o C. Tensiometric studies on irradiated collagen films showed a dose-dependent reduction in both the break load and elongation before breaking. A small reduction in the break load and stretch to breaking was also observed following treatment with ethylene oxide. The findings presented favour ethylene oxide as a method of sterilization of both the composite membrane and its individual components. However, gamma-irradiation produced no toxic effects or adverse tissue reaction under the conditions described, and is more convenient to use. Hence, provided that the efficacy of the membrane would not be compromised by the higher rate of degradation, it could also be considered for sterilization of the material. (author)

  17. Method and apparatus for in-system redundant array repair on integrated circuits

    Science.gov (United States)

    Bright, Arthur A.; Crumley, Paul G.; Dombrowa, Marc B.; Douskey, Steven M.; Haring, Rudolf A.; Oakland, Steven F.; Ouellette, Michael R.; Strissel, Scott A.

    2007-12-18

    Disclosed is a method of repairing an integrated circuit of the type comprising of a multitude of memory arrays and a fuse box holding control data for controlling redundancy logic of the arrays. The method comprises the steps of providing the integrated circuit with a control data selector for passing the control data from the fuse box to the memory arrays; providing a source of alternate control data, external of the integrated circuit; and connecting the source of alternate control data to the control data selector. The method comprises the further step of, at a given time, passing the alternate control data from the source thereof, through the control data selector and to the memory arrays to control the redundancy logic of the memory arrays.

  18. Design structure for in-system redundant array repair in integrated circuits

    Science.gov (United States)

    Bright, Arthur A.; Crumley, Paul G.; Dombrowa, Marc; Douskey, Steven M.; Haring, Rudolf A.; Oakland, Steven F.; Quellette, Michael R.; Strissel, Scott A.

    2008-11-25

    A design structure for repairing an integrated circuit during operation of the integrated circuit. The integrated circuit comprising of a multitude of memory arrays and a fuse box holding control data for controlling redundancy logic of the arrays. The design structure provides the integrated circuit with a control data selector for passing the control data from the fuse box to the memory arrays; providing a source of alternate control data, external of the integrated circuit; and connecting the source of alternate control data to the control data selector. The design structure further passes the alternate control data from the source thereof, through the control data selector and to the memory arrays to control the redundancy logic of the memory arrays.

  19. Method and apparatus for in-system redundant array repair on integrated circuits

    Science.gov (United States)

    Bright, Arthur A [Croton-on-Hudson, NY; Crumley, Paul G [Yorktown Heights, NY; Dombrowa, Marc B [Bronx, NY; Douskey, Steven M [Rochester, MN; Haring, Rudolf A [Cortlandt Manor, NY; Oakland, Steven F [Colchester, VT; Ouellette, Michael R [Westford, VT; Strissel, Scott A [Byron, MN

    2008-07-29

    Disclosed is a method of repairing an integrated circuit of the type comprising of a multitude of memory arrays and a fuse box holding control data for controlling redundancy logic of the arrays. The method comprises the steps of providing the integrated circuit with a control data selector for passing the control data from the fuse box to the memory arrays; providing a source of alternate control data, external of the integrated circuit; and connecting the source of alternate control data to the control data selector. The method comprises the further step of, at a given time, passing the alternate control data from the source thereof, through the control data selector and to the memory arrays to control the redundancy logic of the memory arrays.

  20. A systems-based investigation into vitamin D and skeletal muscle repair, regeneration, and hypertrophy.

    Science.gov (United States)

    Owens, Daniel J; Sharples, Adam P; Polydorou, Ioanna; Alwan, Nura; Donovan, Timothy; Tang, Jonathan; Fraser, William D; Cooper, Robert G; Morton, James P; Stewart, Claire; Close, Graeme L

    2015-12-15

    Skeletal muscle is a direct target for vitamin D. Observational studies suggest that low 25[OH]D correlates with functional recovery of skeletal muscle following eccentric contractions in humans and crush injury in rats. However, a definitive association is yet to be established. To address this gap in knowledge in relation to damage repair, a randomised, placebo-controlled trial was performed in 20 males with insufficient concentrations of serum 25(OH)D (45 ± 25 nmol/l). Prior to and following 6 wk of supplemental vitamin D3 (4,000 IU/day) or placebo (50 mg of cellulose), participants performed 20 × 10 damaging eccentric contractions of the knee extensors, with peak torque measured over the following 7 days of recovery. Parallel experimentation using isolated human skeletal muscle-derived myoblast cells from biopsies of 14 males with low serum 25(OH)D (37 ± 11 nmol/l) were subjected to mechanical wound injury, which enabled corresponding in vitro studies of muscle repair, regeneration, and hypertrophy in the presence and absence of 10 or 100 nmol 1α,25(OH)2D3. Supplemental vitamin D3 increased serum 25(OH)D and improved recovery of peak torque at 48 h and 7 days postexercise. In vitro, 10 nmol 1α,25(OH)2D3 improved muscle cell migration dynamics and resulted in improved myotube fusion/differentiation at the biochemical, morphological, and molecular level together with increased myotube hypertrophy at 7 and 10 days postdamage. Together, these preliminary data are the first to characterize a role for vitamin D in human skeletal muscle regeneration and suggest that maintaining serum 25(OH)D may be beneficial for enhancing reparative processes and potentially for facilitating subsequent hypertrophy. Copyright © 2015 the American Physiological Society.

  1. [Direct repair of adolescent lumbar spondylolysis using a pedicle screw-laminar hook system by paramedian approach].

    Science.gov (United States)

    Wang, Bin; Tang, Yong-hua; Tang, Hong-chao; Jin, Cai-yi

    2011-08-01

    To discuss the indication and clinical effect of direct repair of adolescent lumbar spondylolysis by screw-laminar hook system. From August 2003 to December 2008, 28 patients (13 males and 15 females,ranging in age from 15 and 26 years, averaged 21.6 years) with lumbar spondylolysis were treated with isthmic bone grafting and internal fixation with a pedicle screw-laminar hook system. Three patients had spondylolysis at L3, L4; 5 patients had spondylolysis at L4, L5; 8 patients had spondylolysis at L4; and 12 patients had spondylolysis at L5. All the patients had low back pain and lasted over 6 months. According to preoperative and postoperative plain radiograph, CT scan and Macnab criteria, the fusion rate and clinical effect of this technique were evaluated. All the patients were followed up with a mean period of 14.9 months, ranging from 9 to 24 months. All the patients had bony union according to the X-rays and CT scan. According to the calculation results of Macnab criteria, 22 patients got an excellent result, 5 good and 1 fair. The direct repair of adolescent lumbar spondylolysis with pedicle screw-laminar hook system can shorten length of operation,decrease blood loss, preserve more posterior structures of spine and avoid iatrogenic instability of spine. The postoperative immediate stability of vertebral segment is acquired and the mobility of adjacent intervertebral discs is reserved. The screw-laminar hook system for the treatment of adolescent spondylolisthesis can get satisfactory clinical results.

  2. Evaluation of possible occurrence of mutation in MMR repair system genes in resistant and sensitiveclinical strains of Mycobacterium tuberculosisby using sequencing method

    Directory of Open Access Journals (Sweden)

    AmirPoyan Afzali

    2016-07-01

    Full Text Available Background:during recent years, the incidence and spread of drug resistance in Mycobacterium tuberculosis, the bacterium causing tuberculosis, has set this disease in World Health Organizationpriorities alignment of diseases like AIDS and hepatitis. Study of close examination of resistant and susceptible clinical strains genotypes is necessary to overcome drug resistance. Among the numerous repair systems, only there are limited number of encoding genes of DNA repair enzymes in Mycobacterium tuberculosis. Commonly these genes have been conserved and any changes among them likely increasethe mutation occurance due to the impossibility of correctionof spontaneous mutations insensitive strains of this bacteria.mut genes encodeDNA repairable enzymes.This study investigated the mutations in these genes and the effect of these mutations on tuberculosis drug resistance. Materials&Methods: In this study,of 29 available specimens,we were selected 8 susceptible strains and 21 resistantstrains andafter ordering appropriate primers and performing the proliferation reaction two types of amplicons produced which includingfragments of genes mut T2 and mut T4 and they were sent inorder to sequencing. Results:The results of chain reactionprimer represents an appropriate choice of primerswhich were investigated. Sequencing results showed that overall 73% of resistant strains that had been selected for study of mutT4gene, have no mutations in codons 48of mutT4 gene, and 70% of resistant strains have no GGA >>> CGA mutation at codon 58 of mutT2 gene. Conclusion: One of the strategies to overcome tuberculosis drug resistance is a close examination of genotypes of resistant and susceptible clinical strains. Results of this study was performedby examining changes in mut T2 and mut T4 gene sequence. The mutation in mut T2 always associated with mutation in mut T4, in this way, the first mutation may occurs in mut T4and after that, the second mutationmay occurs in mut T

  3. Materials Knowledge Systems in Python - A Data Science Framework for Accelerated Development of Hierarchical Materials.

    Science.gov (United States)

    Brough, David B; Wheeler, Daniel; Kalidindi, Surya R

    2017-03-01

    There is a critical need for customized analytics that take into account the stochastic nature of the internal structure of materials at multiple length scales in order to extract relevant and transferable knowledge. Data driven Process-Structure-Property (PSP) linkages provide systemic, modular and hierarchical framework for community driven curation of materials knowledge, and its transference to design and manufacturing experts. The Materials Knowledge Systems in Python project (PyMKS) is the first open source materials data science framework that can be used to create high value PSP linkages for hierarchical materials that can be leveraged by experts in materials science and engineering, manufacturing, machine learning and data science communities. This paper describes the main functions available from this repository, along with illustrations of how these can be accessed, utilized, and potentially further refined by the broader community of researchers.

  4. Lightning protecting materials used on radar system

    NARCIS (Netherlands)

    Blaj, M.A.; Damstra, Geert C.; Buesink, Frederik Johannes Karel; Leferink, Frank Bernardus Johannes

    2009-01-01

    Because of the extensive use in modern systems of very sensitive electronic components, lightning strikes does not represent only a threat, but something that cannot be neglected anymore and safety hazards caused by direct and indirect lightning to the aircraft or naval industry. Everyday new

  5. International congress on DNA damage and repair: Book of abstracts

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-01

    This document contains the abstracts of 105 papers presented at the Congress. Topics covered include the Escherichia coli nucleotide excision repair system, DNA repair in malignant transformations, defective DNA repair, and gene regulation. (TEM)

  6. International congress on DNA damage and repair: Book of abstracts

    International Nuclear Information System (INIS)

    1987-01-01

    This document contains the abstracts of 105 papers presented at the Congress. Topics covered include the Escherichia coli nucleotide excision repair system, DNA repair in malignant transformations, defective DNA repair, and gene regulation

  7. U.S. national nuclear material control and accounting system

    International Nuclear Information System (INIS)

    Taylor, S; Terentiev, V G

    1998-01-01

    Issues related to nuclear material control and accounting and illegal dealing in these materials were discussed at the April 19--20, 1996 Moscow summit meeting (G7 + Russia). The declaration from this meeting reaffirmed that governments are responsible for the safety of all nuclear materials in their possession and for the effectiveness of the national control and accounting system for these materials. The Russian delegation at this meeting stated that ''the creation of a nuclear materials accounting, control, and physical protection system has become a government priority''. Therefore, in order to create a government nuclear material control and accounting system for the Russian Federation, it is critical to study the structure, operating principles, and regulations supporting the control and accounting of nuclear materials in the national systems of nuclear powers. In particular, Russian specialists have a definite interest in learning about the National Nuclear Material Control and Accounting System of the US, which has been operating successfully as an automated system since 1968

  8. [Establishment of traceability system of Chinese medicinal materials' quality].

    Science.gov (United States)

    Qi, Yao-dong; Gao, Shi-man; Liu, Hai-tao; Li, Xi-wen; Wei, Jian-he; Zhang, Ben-gang; Sun, Xiao-bo; Xiao, Pei-gen

    2015-12-01

    The quality of Chinese medicinal materials relates greatly to the clinical curative effect and security. In order to ensure the quality and safety of Chinese medicinal materials, a systematic and operable traceability system needs to be established. It can realize the whole process of quality and safety management of Chinese medicinal materials "from production to consumption" through recording and inquiring information and recalling defective products, which is an important direction for the future development of traditional Chinese medicine. But it is still at the exploration and trial stage. In this paper, a framework of Chinese medicinal materials' quality and safety traceability system was established on the basis of the domestic and international experience about the construction of food and agricultural products traceability systems. The relationship between traceability system of Chinese medicinal materials' quality and GAP, GMP, GSP was analyzed, and the possible problems and the corresponding solutions were discussed.

  9. Method of treatment in a system passing radioactive material

    Energy Technology Data Exchange (ETDEWEB)

    Kamiya, K; Kinoshita, M; Asakura, Y

    1976-05-14

    A method to ensure the safety of the reactor and reduce radiation exposure dose by preventing oxygen hydrogen reaction of the reactor off-gas and accumulation of the radioactive material is described. Substances which are accumulated in an off-gas duct and are likely to capture radioactive material (for instance Pd catalyst falling from a recombiner) is changed into a stable material (for instance, PdI/sub 2/) which is hot likely to capture radioactive material through reaction with a stabilizer (for instance, I/sub 2/, Cl/sub 2/, HCl, etc.). This stabilized material is washed off the atomic power plant system.

  10. Materials to Engineer the Immune System

    Science.gov (United States)

    2011-04-01

    alone (Lysate), or with GM-CSF and lysate (GM+Lys), and 14 days later 200,000 NT1 cells were injected into the mammary pad. Mice survival was...followed over time. Fig. 2. Therapeutic vaccination against NT1 transplantable tumors. NT1 cells (200,000) were injected into the mammary...Engineer the Immune System David Mooney Harvard College Cambridge, MA 02136 Dendritic cells , GM-CSF, CpG, poly(lactide-co-glycolide) The

  11. On strength of porous material - simple systems and densified systems

    DEFF Research Database (Denmark)

    Nielsen, Lauge Fuglsang

    1997-01-01

    The question of non-destructive testing of porous materials has always been of interest for the engineering profession. A number of empirically based MOE-MOR relations between stiffness (Modulus Of Elasticity) and strength (Modulus Of Rupture) of materials have been established in order to control...

  12. Security features of a nuclear material accounting system

    International Nuclear Information System (INIS)

    Erkkila, B.H.

    1988-01-01

    The Los Alamos Nuclear Material Accounting and Safeguards System (MASS) is a near-real-time accountability system for bulk materials, discrete items, and materials undergoing dynamic processing. MASS has evolved from a 80-column, card-based process control system to a very sophisticated computer system. Recently, the computer hardware was upgraded to a modern transaction oriented central computer system designed to accommodate extensive growth in the foreseeable future. The security of the MASS computer system is provided through various access controls. There are two kinds of access controls to be addressed. They are physical access control to the hardware which make up the system and access control to the software. There are many features which provide a measure of security to the hardware that are discussed. Access to the software is controlled by a security password. Access to various transaction activities in the system is controlled through the level of MASS under privilege. Details of MASS user privilege are discussed

  13. The food-borne pathogen Campylobacter jejuni depends on the AddAB DNA repair system to defend against bile in the intestinal environment.

    Science.gov (United States)

    Gourley, Christopher R; Negretti, Nicholas M; Konkel, Michael E

    2017-10-31

    Accurate repair of DNA damage is crucial to ensure genome stability and cell survival of all organisms. Bile functions as a defensive barrier against intestinal colonization by pathogenic microbes. Campylobacter jejuni, a leading bacterial cause of foodborne illness, possess strategies to mitigate the toxic components of bile. We recently found that growth of C. jejuni in medium with deoxycholate, a component of bile, caused DNA damage consistent with the exposure to reactive oxygen species. We hypothesized that C. jejuni must repair DNA damage caused by reactive oxygen species to restore chromosomal integrity. Our efforts focused on determining the importance of the putative AddAB DNA repair proteins. A C. jejuni addAB mutant demonstrated enhanced sensitivity to deoxycholate and was impaired in DNA double strand break repair. Complementation of the addAB mutant restored resistance to deoxycholate, as well as function of the DNA double strand break repair system. The importance of these findings translated to the natural host, where the AddAB system was found to be required for efficient C. jejuni colonization of the chicken intestine. This research provides new insight into the molecular mechanism utilized by C. jejuni, and possibly other intestinal pathogens, to survive in the presence of bile.

  14. Minimal access direct spondylolysis repair using a pedicle screw-rod system: a case series

    Directory of Open Access Journals (Sweden)

    Mohi Eldin Mohamed

    2012-11-01

    Full Text Available Abstract Introduction Symptomatic spondylolysis is always challenging to treat because the pars defect causing the instability needs to be stabilized while segmental fusion needs to be avoided. Direct repair of the pars defect is ideal in cases of spondylolysis in which posterior decompression is not necessary. We report clinical results using segmental pedicle-screw-rod fixation with bone grafting in patients with symptomatic spondylolysis, a modification of a technique first reported by Tokuhashi and Matsuzaki in 1996. We also describe the surgical technique, assess the fusion and analyze the outcomes of patients. Case presentation At Cairo University Hospital, eight out of twelve Egyptian patients’ acute pars fractures healed after conservative management. Of those, two young male patients underwent an operative procedure for chronic low back pain secondary to pars defect. Case one was a 25-year-old Egyptian man who presented with a one-year history of axial low back pain, not radiating to the lower limbs, after falling from height. Case two was a 29-year-old Egyptian man who presented with a one-year history of axial low back pain and a one-year history of mild claudication and infrequent radiation to the leg, never below the knee. Utilizing a standardized mini-access fluoroscopically-guided surgical protocol, fixation was established with two titanium pedicle screws place into both pedicles, at the same level as the pars defect, without violating the facet joint. The cleaned pars defect was grafted; a curved titanium rod was then passed under the base of the spinous process of the affected vertebra, bridging the loose fragment, and attached to the pedicle screw heads, to uplift the spinal process, followed by compression of the defect. The patients were discharged three days after the procedure, with successful fusion at one-year follow-up. No rod breakage or implant-related complications were reported. Conclusions Where there is no

  15. Outline of material accountancy system for Rokkasho reprocessing plant

    International Nuclear Information System (INIS)

    Kitamura, Touko; Yamazaki Yoshihiro; Ai, Hironobu

    2004-01-01

    In January 2004, Facility Attachment (FA) for Rokkasho Reprocessing Plant (RRP) was entered into force and the safeguards has been implemented in accordance with the FA. So operator must carry out the effectual material accountancy on the basis of facility operation. RRP is large and complex facility and operated based on automatic and remote system. For efficient material accounting viewpoint, the system especially automatic data collection is established using RRP computer network. The paper describes the outline of material accountancy system, the structure of RRP computer network including how to collect the source data, to convert the batch data and the reporting. (author)

  16. Some areas of reliability technique which have been neglected to some extent - maintainability - human reliability - mechanical reliability - repairable systems

    International Nuclear Information System (INIS)

    Akersten, P.A.

    1985-01-01

    The present thesis consists of four papers, three of which are of a expositary nature and one more theoretical. The first two papers have a natural coupling to the man-machine interface. The first paper is devoted to the concept of maintainability and the role of man as maintenance technician. The second paper discusses aspects of human reliability, mainly studying man as operator. However, maintenance tasks can be studied in the same manner. The third paper concerns reliability prediction for mechanical components. This is an area of vital importance for the reliability practitioner, who needs realistic and easy-to-use mathematical models for different failure modes. The fourth paper discusses mathematical models for repairable systems, especially the problem of testing whether a constant event intensity model is adequate or not. (author)

  17. Demonstration personnel and material tracking system at ANL-W

    International Nuclear Information System (INIS)

    Roybal, J.A.; Ortiz, S.; Henslee, S.P.

    1988-01-01

    A Personnel and Material Tracking System (PMTS) was demonstrated in the Fuel Manufacturing Facility (FMF) at Argonne National Laboratories-West (ANL-W) in July, 1987. The PMTS is intended to aid in the transfer of inventory materials from area to area within a facility such as FMF. It is also intended to assure that only those personnel who are authorized to do so may conduct these transfer operations. The PMTS Personnel Movement (PM) subsystem uses portals installed between areas to alert the system to the movement of personnel between areas. The portals are composed to two sensors, one on either side of a proximity badge reader, to detect the presence of personnel entering the portal area. However, a restricted area can be assigned to any badge holder which will cause the system to issue an alert if the badge holder passes into his/her restricted area. The PM subsystem is intended to be transparent when in use. The PMTS Inventory Material Access (IMA) subsystem provides two functions: material control and material access. The material control is provided by the Wireless Alarm Transmission of Container Handling (WATCH) system which is a sensor rf transmitter system that detects item movements. Material access is provided by the Mobile Accountability Verification Inventory Station (MAVIS) system which is a self-powered smart barcode reader

  18. Development of an expert system for radioactive material transportation

    International Nuclear Information System (INIS)

    Tamanoi, K.; Ishitobi, M.; Shinohara, Y.

    1990-01-01

    An expert system to deal with radioactive material transportation was developed. This expert system is based on 'Regulations for the Safe Transport of Radioactive Material' by IAEA issued 1985. IAEA published the regulations under such environments that safety transportation has become increasingly being focused as uses of radioactive materials are more pervasive, not only in nuclear field but also in non-nuclear purposes. Attentions are payed for operators and environment to establish safety in handling radioactive materials. In the 1985 regulations, detailed categorization of radioactive materials and, correspondingly, new classification of packages are introduced. This categorization is more complicated than old regulations, leading us to develop an expert system to evaluate easily the packages categorization. (author)

  19. Repair of segmental bone defect using Totally Vitalized tissue engineered bone graft by a combined perfusion seeding and culture system.

    Directory of Open Access Journals (Sweden)

    Lin Wang

    Full Text Available BACKGROUND: The basic strategy to construct tissue engineered bone graft (TEBG is to combine osteoblastic cells with three dimensional (3D scaffold. Based on this strategy, we proposed the "Totally Vitalized TEBG" (TV-TEBG which was characterized by abundant and homogenously distributed cells with enhanced cell proliferation and differentiation and further investigated its biological performance in repairing segmental bone defect. METHODS: In this study, we constructed the TV-TEBG with the combination of customized flow perfusion seeding/culture system and β-tricalcium phosphate (β-TCP scaffold fabricated by Rapid Prototyping (RP technique. We systemically compared three kinds of TEBG constructed by perfusion seeding and perfusion culture (PSPC method, static seeding and perfusion culture (SSPC method, and static seeding and static culture (SSSC method for their in vitro performance and bone defect healing efficacy with a rabbit model. RESULTS: Our study has demonstrated that TEBG constructed by PSPC method exhibited better biological properties with higher daily D-glucose consumption, increased cell proliferation and differentiation, and better cell distribution, indicating the successful construction of TV-TEBG. After implanted into rabbit radius defects for 12 weeks, PSPC group exerted higher X-ray score close to autograft, much greater mechanical property evidenced by the biomechanical testing and significantly higher new bone formation as shown by histological analysis compared with the other two groups, and eventually obtained favorable healing efficacy of the segmental bone defect that was the closest to autograft transplantation. CONCLUSION: This study demonstrated the feasibility of TV-TEBG construction with combination of perfusion seeding, perfusion culture and RP technique which exerted excellent biological properties. The application of TV-TEBG may become a preferred candidate for segmental bone defect repair in orthopedic and

  20. Mathematical Methods of System Analysis in Construction Materials

    Science.gov (United States)

    Garkina, Irina; Danilov, Alexander

    2017-10-01

    System attributes of construction materials are defined: complexity of an object, integrity of set of elements, existence of essential, stable relations between elements defining integrative properties of system, existence of structure, etc. On the basis of cognitive modelling (intensive and extensive properties; the operating parameters) materials (as difficult systems) and creation of the cognitive map the hierarchical modular structure of criteria of quality is under construction. It actually is a basis for preparation of the specification on development of material (the required organization and properties). Proceeding from a modern paradigm (model of statement of problems and their decisions) of development of materials, levels and modules are specified in structure of material. It when using the principles of the system analysis allows to considered technological process as the difficult system consisting of elements of the distinguished specification level: from atomic before separate process. Each element of system depending on an effective objective is considered as separate system with more detailed levels of decomposition. Among them, semantic and qualitative analyses of an object (are considered a research objective, decomposition levels, separate elements and communications between them come to light). Further formalization of the available knowledge in the form of mathematical models (structural identification) is carried out; communications between input and output parameters (parametrical identification) are defined. Hierarchical structures of criteria of quality are under construction for each allocated level. On her the relevant hierarchical structures of system (material) are under construction. Regularities of structurization and formation of properties, generally are considered at the levels from micro to a macrostructure. The mathematical model of material is represented as set of the models corresponding to private criteria by which separate

  1. Defense Nuclear Material Stewardship Integrated Inventory Information Management System (IIIMS).

    Energy Technology Data Exchange (ETDEWEB)

    Aas, Christopher A.; Lenhart, James E.; Bray, Olin H.; Witcher, Christina Jenkin

    2004-11-01

    Sandia National Laboratories was tasked with developing the Defense Nuclear Material Stewardship Integrated Inventory Information Management System (IIIMS) with the sponsorship of NA-125.3 and the concurrence of DOE/NNSA field and area offices. The purpose of IIIMS was to modernize nuclear materials management information systems at the enterprise level. Projects over the course of several years attempted to spearhead this modernization. The scope of IIIMS was broken into broad enterprise-oriented materials management and materials forecasting. The IIIMS prototype was developed to allow multiple participating user groups to explore nuclear material requirements and needs in detail. The purpose of material forecasting was to determine nuclear material availability over a 10 to 15 year period in light of the dynamic nature of nuclear materials management. Formal DOE Directives (requirements) were needed to direct IIIMS efforts but were never issued and the project has been halted. When restarted, duplicating or re-engineering the activities from 1999 to 2003 is unnecessary, and in fact future initiatives can build on previous work. IIIMS requirements should be structured to provide high confidence that discrepancies are detected, and classified information is not divulged. Enterprise-wide materials management systems maintained by the military can be used as overall models to base IIIMS implementation concepts upon.

  2. From precision polymers to complex materials and systems

    NARCIS (Netherlands)

    Lutz, J.F.; Lehn, J.M.; Meijer, E.W.; Matyjaszewski, K.

    2016-01-01

    Complex chemical systems, such as living biological matter, are highly organized structures based on discrete molecules in constant dynamic interactions. These natural materials can evolve and adapt to their environment. By contrast, man-made materials exhibit simpler properties. In this Review, we

  3. Corrosion of structural materials for Generation IV systems

    International Nuclear Information System (INIS)

    Balbaud-Celerier, F.; Cabet, C.; Courouau, J.L.; Martinelli, L.; Arnoux, P.

    2009-01-01

    The Generation IV International Forum aims at developing future generation nuclear energy systems. Six systems have been selected for further consideration: sodium-cooled fast reactor (SFR), gas-cooled fast reactor (GFR), lead-cooled fast reactor (LFR), molten salt reactor (MSR), supercritical water-cooled reactor (SCWR) and very high temperature reactor (VHTR). CEA, in the frame of a national program, of EC projects and of the GIF, contributes to the structural materials developments and research programs. Particularly, corrosion studies are being performed in the complex environments of the GEN IV systems. As a matter of fact, structural materials encounter very severe conditions regarding corrosion concerns: high temperatures and possibly aggressive chemical environments. Therefore, the multiple environments considered require also a large diversity of materials. On the other hand, the similar levels of working temperatures as well as neutron spectrum imply also similar families of materials for the various systems. In this paper, status of the research performed in CEA on the corrosion behavior of the structural material in the different environments is presented. The materials studied are either metallic materials as austenitic (or Y, La, Ce doped) and ferrito-martensitic steels, Ni base alloys, ODS steels, or ceramics and composites. In all the environments studied, the scientific approach is identical, the objective being in all cases the understanding of the corrosion processes to establish recommendations on the chemistry control of the coolant and to predict the long term behavior of the materials by the development of corrosion models. (author)

  4. Development of hotcell transportation system technology for high radioactive material

    International Nuclear Information System (INIS)

    Seo, K. S.; Seo, C. S.; Lee, J. C.

    2012-04-01

    In the first stage of the research, the transportation and storage characteristics analysis of the pyroprocess materials, the development of horizontal type hot cell transportation system, and the design of interim storage system for the pyroprocess material are conducted. The optimized capacity, transportation frequency and operation period of pyroprocess facility are found using the logistics analysis program developed in this project. A new hot cell transportation system was designed. Through the safety analysis and test for the hot cell transportation system, the design license has been approved. A new type hot cell docking system with superior performance has been developed with a patented rotating lid system. We have reached to a unique concept of interim storage of pyroprocess materials and selected a system through a comparative evaluation of existing ones. In the second stage of the research, transportation/storage/sealing devices for PRIDE recovered material/wastes were developed. And test model for the devices in engineering scale facility were also developed. The design requirements for a vertical docking system were evaluated and the performance assessment using a scaled mock-up was conducted. Integrated storage management technology was evaluated for an efficient management of process materials. A heat transfer simulation and characteristics analysis for the storage system were conducted. The derivation of design requirements, design and fabrication of a canister test model, and preliminary safety assessment were conducted

  5. Advanced materials and coatings for energy conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    St Pierre, George R. [Ohio State Univ., Materials Science and Engineering Dept., Columbus, OH (United States)

    1997-12-31

    Following an historical review of the development of high-temperature alloys for energy conversion systems including turbine engines, some of the current advances in single crystal materials, intermetallics, metal-matrix composites, and ceramic-matrix composites are discussed. Particular attention is directed at creep phenomena, fatigue properties and oxidation resistance. Included within the discussions is the current status of carbon/carbon composites as potential high-temperature engineering materials and the development of coating systems for thermal barrier and oxidation protection. The specific influences of combustion gas compositions, i.e., oxidation potential, sulfur, halides, etc. are discussed. A current list of eligible advanced materials and coatings systems is presented and assessed. Finally, the critical failure mechanism and life-prediction parameters for some of the new classes of advanced structural materials are elaborated with the view to achieving affordability and extended life with a high degree of reliability. Examples are drawn from a variety of energy conversion systems. (Author)

  6. Basic components of a national control system for nuclear materials

    International Nuclear Information System (INIS)

    Rabot, G.

    1986-01-01

    The paper presents the different aspects related to the organization and the functioning of a national control and accounting system for nuclear materials. The legal aspects and the relations with the IAEA are included

  7. Development of a comprehensive nuclear materials accountancy system at JAEA

    International Nuclear Information System (INIS)

    Takeda, Hideyuki; Usami, Masayuki; Hirosawa, Naonori; Fujita, Yoshihisa; Kodani, Yoshiki; Komata, Kazuhiro

    2007-01-01

    The Japan Atomic Energy Agency (JAEA) is submitting various types of accounting reports of international controlled materials to the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) based on domestic laws and regulations. JAEA developed a comprehensive Nuclear Material Accountancy System to achieve uniform management of the data of each facility by using a company-wide database. Personal computers in each facility are connected throughout the company using an in-house network to create the comprehensive Nuclear Material Accountancy System. This System uses personal computers to facilitate timely communication and for easy maintenance and operation. Efficient data processing and quality control functions for accountancy reporting are also realized by this System. In addition, the System has the ability to extract and summarize data about Plutonium Management in the company for public announcement. This report introduces and describes the details and functions of this System. (author)

  8. Test plan for buried waste containment system materials

    International Nuclear Information System (INIS)

    Weidner, J.; Shaw, P.

    1997-03-01

    The objectives of the FY 1997 barrier material work at the Idaho National Engineering and Environmental Laboratory are to (1) select a waste barrier material and verify that it is compatible with the Buried Waste Containment System Process, and (2) determine if, and how, the Buried Waste Containment System emplacement process affects the material properties and performance (on proof of principle scale). This test plan describes a set of measurements and procedures used to validate a waste barrier material for the Buried Waste Containment System. A latex modified proprietary cement manufactured by CTS Cement Manufacturing Company will be tested. Emplacement properties required for the Buried Waste Containment System process are: slump between 8 and 10 in., set time between 15 and 30 minutes, compressive strength at set of 20 psi minimum, and set temperature less than 100 degrees C. Durability properties include resistance to degradation from carbonate, sulfate, and waste-site soil leachates. A set of baseline barrier material properties will be determined to provide a data base for comparison with the barrier materials when tested in the field. The measurements include permeability, petrographic analysis to determine separation and/or segregation of mix components, and a set of mechanical properties. The measurements will be repeated on specimens from the field test material. The data will be used to determine if the Buried Waste Containment System equipment changes the material. The emplacement properties will be determined using standard laboratory procedures and instruments. Durability of the barrier material will be evaluated by determining the effect of carbonate, sulfate, and waste-site soil leachates on the compressive strength of the barrier material. The baseline properties will be determined using standard ASTM procedures. 9 refs., 1 fig., 2 tabs

  9. The role of the HCR system in the repair of lethal lesions of Bacillus subtilis phages and their transfecting DNA damaged by radiation and alkylating agents

    International Nuclear Information System (INIS)

    Vizdalova, M.; Janovska, E.; Zhestyanikov, V.D.

    1980-01-01

    The role of the HCR system in the repair of prelethal lesions induced by UV light, γ radiation and alkylating agents was studied in the Bacillus subtilis SPP1 phage, its heat sensitive mutants (N3, N73 nad ts 1 ) and corresponding infectious DNA. The survival of phages and their transfecting DNA after treatment with UV light is substantially higher in hcr + cells than in hcr cells, the differences being more striking in intact phages than in their transfecting DNA's. Repair inhibitors reduce survival in hcr + cells: caffeine lowers the survival of UV-irradiated phage SPP1 in exponentially growing hcr + cells but has no effect on its survival in competent hcr + cells; acriflavin and ethidium bromide decrease the survival of the UV-irradiated SPP1 phage in both exponentially growing and competent hcr + cells to the level of survival observed in hcr cells; moreover, ethidium bromide lowers the number of infective centres in hcr + cells of the UV-irradiated DNA of the SPP1 phage. Repair inhibitors do not lower the survival of the UV-irradiated phages or their DNA in hcr cells. The repair mechanism under study also effectively repairs lesions induced by polyfunctional alkylating agents in the transfecting DNA's of B. subtilis phages but is not functional with lesions induced by these agents in free phages and lesions caused in the phages and their DNA by ethyl methanesulphonate or γ radiation. (author)

  10. Activation of Saccharomyces cerevisiae Mlh1-Pms1 Endonuclease in a Reconstituted Mismatch Repair System*

    Science.gov (United States)

    Smith, Catherine E.; Bowen, Nikki; Graham, William J.; Goellner, Eva M.; Srivatsan, Anjana; Kolodner, Richard D.

    2015-01-01

    Previous studies reported the reconstitution of an Mlh1-Pms1-independent 5′ nick-directed mismatch repair (MMR) reaction using Saccharomyces cerevisiae proteins. Here we describe the reconstitution of a mispair-dependent Mlh1-Pms1 endonuclease activation reaction requiring Msh2-Msh6 (or Msh2-Msh3), proliferating cell nuclear antigen (PCNA), and replication factor C (RFC) and a reconstituted Mlh1-Pms1-dependent 3′ nick-directed MMR reaction requiring Msh2-Msh6 (or Msh2-Msh3), exonuclease 1 (Exo1), replication protein A (RPA), RFC, PCNA, and DNA polymerase δ. Both reactions required Mg2+ and Mn2+ for optimal activity. The MMR reaction also required two reaction stages in which the first stage required incubation of Mlh1-Pms1 with substrate DNA, with or without Msh2-Msh6 (or Msh2-Msh3), PCNA, and RFC but did not require nicking of the substrate, followed by a second stage in which other proteins were added. Analysis of different mutant proteins demonstrated that both reactions required a functional Mlh1-Pms1 endonuclease active site, as well as mispair recognition and Mlh1-Pms1 recruitment by Msh2-Msh6 but not sliding clamp formation. Mutant Mlh1-Pms1 and PCNA proteins that were defective for Exo1-independent but not Exo1-dependent MMR in vivo were partially defective in the Mlh1-Pms1 endonuclease and MMR reactions, suggesting that both reactions reflect the activation of Mlh1-Pms1 seen in Exo1-independent MMR in vivo. The availability of this reconstituted MMR reaction should now make it possible to better study both Exo1-independent and Exo1-dependent MMR. PMID:26170454

  11. Activation of Saccharomyces cerevisiae Mlh1-Pms1 Endonuclease in a Reconstituted Mismatch Repair System.

    Science.gov (United States)

    Smith, Catherine E; Bowen, Nikki; Graham, William J; Goellner, Eva M; Srivatsan, Anjana; Kolodner, Richard D

    2015-08-28

    Previous studies reported the reconstitution of an Mlh1-Pms1-independent 5' nick-directed mismatch repair (MMR) reaction using Saccharomyces cerevisiae proteins. Here we describe the reconstitution of a mispair-dependent Mlh1-Pms1 endonuclease activation reaction requiring Msh2-Msh6 (or Msh2-Msh3), proliferating cell nuclear antigen (PCNA), and replication factor C (RFC) and a reconstituted Mlh1-Pms1-dependent 3' nick-directed MMR reaction requiring Msh2-Msh6 (or Msh2-Msh3), exonuclease 1 (Exo1), replication protein A (RPA), RFC, PCNA, and DNA polymerase δ. Both reactions required Mg(2+) and Mn(2+) for optimal activity. The MMR reaction also required two reaction stages in which the first stage required incubation of Mlh1-Pms1 with substrate DNA, with or without Msh2-Msh6 (or Msh2-Msh3), PCNA, and RFC but did not require nicking of the substrate, followed by a second stage in which other proteins were added. Analysis of different mutant proteins demonstrated that both reactions required a functional Mlh1-Pms1 endonuclease active site, as well as mispair recognition and Mlh1-Pms1 recruitment by Msh2-Msh6 but not sliding clamp formation. Mutant Mlh1-Pms1 and PCNA proteins that were defective for Exo1-independent but not Exo1-dependent MMR in vivo were partially defective in the Mlh1-Pms1 endonuclease and MMR reactions, suggesting that both reactions reflect the activation of Mlh1-Pms1 seen in Exo1-independent MMR in vivo. The availability of this reconstituted MMR reaction should now make it possible to better study both Exo1-independent and Exo1-dependent MMR. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. Construction of maintenance management system of atomic power plant

    International Nuclear Information System (INIS)

    Shibasaki, Naofumi; Ookawara, Koumei; Suzuki, Masashi

    2005-01-01

    This maintenance management system has the retrieval function of the variation conditions with the three dimensions models and repair history. The structure of system consists of the management data retrieval tool and the total facilities repair plan support tool. The system has the management function of facilities information, a bird's-eye view of three dimensions models, data recording function, output of various kinds of registers, pre-estimation of degradation and the repair plan support function. When the total facilities repair plan support tool is selected, the variation conditions of facilities, repair history and repair cost are shown, and each part of facility and materials is able to display. (S.Y.)

  13. Incorporation of an item/material attribute system into PAMTRAK

    International Nuclear Information System (INIS)

    Anspach, D.A.; Waddoups, I.G.; Fox, E.T.

    1994-01-01

    The Department of Energy (DOE) mission is changing due to the number of nuclear weapon reductions by the United States and the former Soviet Union with long-term storage requirements for DOE sites increasing. New technology to ensure the integrity of special nuclear material (SNM) in storage is available to sites to supplement manual physical inventories. This allows them to decrease operating costs while keeping radiation exposure at minimal levels. We have developed a generic, real time, personnel tracking and material monitoring system named PAMTRAK. Such a system can significantly reduce the number of required, manual physical inventories at DOE sites while increasing assurance that an insider has not diverted or stolen material. Until recently Pamtrak used only material monitoring devices that provided location/containment attributes. However, Westinghouse Electric Corp. and Metrox, Inc. have recently developed hard-wired item/material attribute systems that monitor both temperature and weight. We have incorporated both of these systems into PAMTRAK. If a site employed one of these item/material attribute systems, it could decrease its manual inventory frequency to three years. This paper describes how a site might implement such a system to meet the DOE's requirements

  14. The development of nuclear material accountability system - software user's manual

    International Nuclear Information System (INIS)

    Byeon, Kee Hoh; Kim, Ho Dong; Song, Dae Yong; Ko, Won Il; Hong, Jong Sook; Lee, Byung Doo

    1999-07-01

    We have developed the near-real time nuclear material accountability system, named by DMAS, for DUPIC Test Facility in the basis of the survey of DUPIC process and activities for the accountability of the system, and the review of the rules and regulations related to the nuclear material accounting. Our system adopts the structure and technologies used in COREMAS which was developed by LANL. This technical report illustrates the system structure and program usage as a user manual for DMAS. (author). 56 tabs., 1 fig

  15. The role of the DNA repair system in increasing the viability of E.coli cells under the action of small UV doses

    International Nuclear Information System (INIS)

    Kuzin, A.M.; Vilenchik, M.M.; Isakov, B.K.; AN Kazakhskoj SSR, Alma-Ata. Inst. Botaniki)

    1976-01-01

    The authors studied the action of the ultraviolet light (UV) on the colony-forming ability of E.coli K12-HCR + cultured in a meat infusion broth in the presence of glucose. An unusual shape of the curve indicates that the number of viable cells increases under the action of low UV doses. The experiment was repeated seven times, and each time the phenomenon was fully asserted (p 0.01). So it was suggested that low UV doses (about 140 erg/mm 2 ) activate the system of dark DNA repair (induction of the synthesis of repair enzymes) which repairs 'spontaneous' DNA defects and increases the number of colony-forming cells. (orig.) [de

  16. Role of the DNA repair system in increasing the viability of E. coli cells under the action of small UV doses

    Energy Technology Data Exchange (ETDEWEB)

    Kuzin, A M; Vilenchik, M M; Isakov, B K [AN SSSR, Pushchino-na-Oke. Inst. Biologicheskoj Fiziki; AN Kazakhskoj SSR, Alma-Ata. Inst. Botaniki)

    1976-12-01

    The authors studied the action of the ultraviolet light (UV) on the colony-forming ability of E.coli K12-HCR/sup +/ cultured in a meat infusion broth in the presence of glucose. An unusual shape of the curve indicates that the number of viable cells increases under the action of low UV doses. The experiment was repeated seven times, and each time the phenomenon was fully asserted (p 0.01). So it was suggested that low UV doses (about 140 erg/mm/sup 2/) activate the system of dark DNA repair (induction of the synthesis of repair enzymes) which repairs 'spontaneous' DNA defects and increases the number of colony-forming cells.

  17. Heat storage system utilizing phase change materials government rights

    Science.gov (United States)

    Salyer, Ival O.

    2000-09-12

    A thermal energy transport and storage system is provided which includes an evaporator containing a mixture of a first phase change material and a silica powder, and a condenser containing a second phase change material. The silica powder/PCM mixture absorbs heat energy from a source such as a solar collector such that the phase change material forms a vapor which is transported from the evaporator to the condenser, where the second phase change material melts and stores the heat energy, then releases the energy to an environmental space via a heat exchanger. The vapor is condensed to a liquid which is transported back to the evaporator. The system allows the repeated transfer of thermal energy using the heat of vaporization and condensation of the phase change material.

  18. Nuclear material control systems for nuclear power plants

    International Nuclear Information System (INIS)

    1975-06-01

    Paragraph 70.51(c) of 10 CFR Part 70 requires each licensee who is authorized to possess at any one time special nuclear material in a quantity exceeding one effective kilogram to establish, maintain, and follow written material control and accounting procedures that are sufficient to enable the licensee to account for the special nuclear material in his possession under license. While other paragraphs and sections of Part 70 provide specific requirements for nuclear material control systems for fuel cycle plants, such detailed requirements are not included for nuclear power reactors. This guide identifies elements acceptable to the NRC staff for a nuclear material control system for nuclear power reactors. (U.S.)

  19. Multifactorial analysis of variables influencing the fracture strength of repair joints for provisional restorative materials using the statistically based Taguchi method

    Directory of Open Access Journals (Sweden)

    Chun-Jen Cheng

    2010-06-01

    Conclusion: Within the limitations of this study, these four design factors had different contributions to the fracture strength of repaired provisional restorations. Clinicians must be aware of the sequence of importance in determining better problem-solving methods.

  20. Development of an auto-welding system for CRD nozzle repair welds using a 3D laser vision sensor

    International Nuclear Information System (INIS)

    Park, K.; Kim, Y.; Byeon, J.; Sung, K.; Yeom, C.; Rhee, S.

    2007-01-01

    A control rod device (CRD) nozzle attaches to the hemispherical surface of a reactor head with J-groove welding. Primary water stress corrosion cracking (PWSCC) causes degradation in these welds, which requires that these defect areas be repaired. To perform this repair welding automatically on a complicated weld groove shape, an auto-welding system was developed incorporating a laser vision sensor that measures the 3-dimensional (3D) shape of the groove and a weld-path creation program that calculates the weld-path parameters. Welding trials with a J-groove workpiece were performed to establish a basis for developing this auto-welding system. Because the reactor head is placed on a lay down support, the outer-most region of the CRD nozzle has restricted access. Due to this tight space, several parameters of the design, such as size, weight and movement of the auto-welding system, had to be carefully considered. The cross section of the J-groove weld is basically an oval shape where the included angle of the J-groove ranges from 0 to 57 degrees. To measure the complex shape, we used double lasers coupled to a single charge coupled device (CCD) camera. We then developed a program to generate the weld-path parameters using the measured 3D shape as a basis. The program has the ability to determine the first and final welding positions and to calculate all weld-path parameters. An optimized image-processing algorithm was applied to resolve noise interference and diffused reflection of the joint surfaces. The auto-welding system is composed of a 4-axis manipulator, gas tungsten arc welding (GTAW) power supply, an optimized designed and manufactured GTAW torch and a 3D laser vision sensor. Through welding trials with 0 and 38-degree included-angle workpieces with both J-groove and U-groove weld, the performance of this auto-welding system was qualified for field application