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Sample records for composite cmc systems

  1. Thin Film Heat Flux Sensor Development for Ceramic Matrix Composite (CMC) Systems

    Science.gov (United States)

    Wrbanek, John D.; Fralick, Gustave C.; Hunter, Gary W.; Zhu, Dongming; Laster, Kimala L.; Gonzalez, Jose M.; Gregory, Otto J.

    2010-01-01

    The NASA Glenn Research Center (GRC) has an on-going effort for developing high temperature thin film sensors for advanced turbine engine components. Stable, high temperature thin film ceramic thermocouples have been demonstrated in the lab, and novel methods of fabricating sensors have been developed. To fabricate thin film heat flux sensors for Ceramic Matrix Composite (CMC) systems, the rough and porous nature of the CMC system posed a significant challenge for patterning the fine features required. The status of the effort to develop thin film heat flux sensors specifically for use on silicon carbide (SiC) CMC systems with these new technologies is described.

  2. Flexural Fatigue Behavior of an EBC CMC Composite System In Air and Steam at High Temperature

    Science.gov (United States)

    Jaskowiak, Martha; Bur, Michael; Harder, Bryan; Gorican, Daniel

    2017-01-01

    Both coated and uncoated SiCSiC ceramic matrix composite (CMC) samples were tested in flexure under sustained peak low cycle fatigue (SPLCF) conditions in air or steam at elevated temperatures. The SiCSiC composites were reinforced with 2-D plies of boron nitride coated Hi-Nicalon Type-S SiC fibers which were woven as 5 harness satin (5HS) cloth. The composites were densified by chemical vapor infiltration (CVI) followed by slurry melt infiltration (SMI). A multilayer barium strontium aluminosilicate (BSAS) coating was applied to the samples by a plasma spray method. Fatigue loading limits were determined from monotonic flexure tests at room temperature and 1200oC. Stress levels under the proportional limit of the composite material were selected for the SPLCF tests. After cyclic testing, the composites were evaluated to determine crack propagation and failure modes in the coated and uncoated composites. Microstructural examination was used to identify coating degradation and failure modes of the EBCCMC system.

  3. Ceramic Matrix Composite (CMC) Thermal Protection Systems (TPS) and Hot Structures for Hypersonic Vehicles

    Science.gov (United States)

    Glass, David E.

    2008-01-01

    Thermal protection systems (TPS) and hot structures are required for a range of hypersonic vehicles ranging from ballistic reentry to hypersonic cruise vehicles, both within Earth's atmosphere and non-Earth atmospheres. The focus of this paper is on air breathing hypersonic vehicles in the Earth's atmosphere. This includes single-stage to orbit (SSTO), two-stage to orbit (TSTO) accelerators, access to space vehicles, and hypersonic cruise vehicles. This paper will start out with a brief discussion of aerodynamic heating and thermal management techniques to address the high heating, followed by an overview of TPS for rocket-launched and air-breathing vehicles. The argument is presented that as we move from rocket-based vehicles to air-breathing vehicles, we need to move away from the insulated airplane approach used on the Space Shuttle Orbiter to a wide range of TPS and hot structure approaches. The primary portion of the paper will discuss issues and design options for CMC TPS and hot structure components, including leading edges, acreage TPS, and control surfaces. The current state-of-the-art will be briefly discussed for some of the components. The two primary technical challenges impacting the use of CMC TPS and hot structures for hypersonic vehicles are environmental durability and fabrication, and will be discussed briefly.

  4. CMC

    Indian Academy of Sciences (India)

    Administrator

    increase with the increasing GA content and reduced with enhanced irradiation doses. Consequently, plasticized. CMC/GA blends were selected to be used as an absorbent for dyestuffs. References. Anderson D M and Wang W P 1990 Phytochemistry 29 1193. El-Salmawi K M, Abu Zaid M M, Ibrahim S M, El-Naggar A M.

  5. Ceramic Matrix Composites (CMC) Life Prediction Method Development

    Science.gov (United States)

    Levine, Stanley R.; Calomino, Anthony M.; Ellis, John R.; Halbig, Michael C.; Mital, Subodh K.; Murthy, Pappu L.; Opila, Elizabeth J.; Thomas, David J.; Thomas-Ogbuji, Linus U.; Verrilli, Michael J.

    2000-01-01

    Advanced launch systems (e.g., Reusable Launch Vehicle and other Shuttle Class concepts, Rocket-Based Combine Cycle, etc.), and interplanetary vehicles will very likely incorporate fiber reinforced ceramic matrix composites (CMC) in critical propulsion components. The use of CMC is highly desirable to save weight, to improve reuse capability, and to increase performance. CMC candidate applications are mission and cycle dependent and may include turbopump rotors, housings, combustors, nozzle injectors, exit cones or ramps, and throats. For reusable and single mission uses, accurate prediction of life is critical to mission success. The tools to accomplish life prediction are very immature and not oriented toward the behavior of carbon fiber reinforced silicon carbide (C/SiC), the primary system of interest for a variety of space propulsion applications. This paper describes an approach to satisfy the need to develop an integrated life prediction system for CMC that addresses mechanical durability due to cyclic and steady thermomechanical loads, and takes into account the impact of environmental degradation.

  6. Oxide_Oxide Ceramic Matrix Composite (CMC) Exhaust Mixer Development in the NASA Environmentally Responsible Aviation (ERA) Project

    Science.gov (United States)

    Kiser, J. Douglas; Bansal, Narottam P.; Szelagowski, James; Sokhey, Jagdish; Heffernan, Tab; Clegg, Joseph; Pierluissi, Anthony; Riedell, Jim; Wyen, Travis; Atmur, Steven; hide

    2015-01-01

    LibertyWorks®, a subsidiary of Rolls-Royce Corporation, first studied CMC (ceramic matrix composite) exhaust mixers for potential weight benefits in 2008. Oxide CMC potentially offered weight reduction, higher temperature capability, and the ability to fabricate complex-shapes for increased mixing and noise suppression. In 2010, NASA was pursuing the reduction of NOx emissions, fuel burn, and noise from turbine engines in Phase I of the Environmentally Responsible Aviation (ERA) Project (within the Integrated Systems Research Program). ERA subtasks, including those focused on CMC components, were being formulated with the goal of maturing technology from Proof of Concept Validation (Technology Readiness Level 3 (TRL 3)) to System/Subsystem or Prototype Demonstration in a Relevant Environment (TRL 6). LibertyWorks®, a subsidiary of Rolls-Royce Corporation, first studied CMC (ceramic matrix composite) exhaust mixers for potential weight benefits in 2008. Oxide CMC potentially offered weight reduction, higher temperature capability, and the ability to fabricate complex-shapes for increased mixing and noise suppression. In 2010, NASA was pursuing the reduction of NOx emissions, fuel burn, and noise from turbine engines in Phase I of the Environmentally Responsible Aviation (ERA) Project (within the Integrated Systems Research Program). ERA subtasks, including those focused on CMC components, were being formulated with the goal of maturing technology from Proof of Concept Validation (Technology Readiness Level 3 (TRL 3)) to System/Subsystem or Prototype Demonstration in a Relevant Environment (TRL 6). Oxide CMC component at both room and elevated temperatures. A TRL˜5 (Component Validation in a Relevant Environment) was attained and the CMC mixer was cleared for ground testing on a Rolls-Royce AE3007 engine for performance evaluation to achieve TRL 6.

  7. Novel, Nanotechnology Based CMC composites for Hot Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Very extensive R&D efforts over the past several decades resulted in several classes of high temperature composites offering potential for future hypersonic...

  8. CMC thermal protection system for future reusable launch vehicles: Generic shingle technological maturation and tests

    Science.gov (United States)

    Pichon, T.; Barreteau, R.; Soyris, P.; Foucault, A.; Parenteau, J. M.; Prel, Y.; Guedron, S.

    2009-07-01

    Experimental re-entry demonstrators are currently being developed in Europe, with the objective of increasing the technology readiness level (TRL) of technologies applicable to future reusable launch vehicles. Among these are the Pre-X programme, currently funded by CNES, the French Space Agency, and which is about to enter into development phase B, and the IXV, within the future launcher preparatory programme (FLPP) funded by ESA. One of the major technologies necessary for such vehicles is the thermal protection system (TPS), and in particular the ceramic matrix composites (CMC) based windward TPS. In support of this goal, technology maturation activities named "generic shingle" were initiated beginning of 2003 by SPS, under a CNES contract, with the objective of performing a test campaign of a complete shingle of generic design, in preparation of the development of a re-entry experimental vehicle decided in Europe. The activities performed to date include: the design, manufacturing of two C/SiC panels, finite element model (FEM) calculation of the design, testing of technological samples extracted from a dedicated panel, mechanical pressure testing of a panel, and a complete study of the attachment system. Additional testing is currently under preparation on the panel equipped with its insulation, seal, attachment device, and representative portion of cold structure, to further assess its behaviour in environments relevant to its application The paper will present the activities that will have been performed in 2006 on the prediction and preparation of these modal characterization, dynamic, acoustic as well as thermal and thermo-mechanical tests. Results of these tests will be presented and the lessons learned will be discussed.

  9. Gradient Interphase, 3-D Fiber Architecture CMC's Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A clear need exists for the next generation of Ceramic Matrix Composites (CMC) for Thermal Protection Systems (TPS), propulsion hardware, and other high temperature...

  10. Approaches to polymer-derived CMC matrices

    Science.gov (United States)

    Hurwitz, Frances I.

    1992-01-01

    The use of polymeric precursors to ceramics permits the fabrication of large, complex-shaped ceramic matrix composites (CMC's) at temperatures which do not degrade the fiber. Processing equipment and techniques readily available in the resin matrix composite industry can be adapted for CMC fabrication using this approach. Criteria which influence the choice of candidate precursor polymers, the use of fillers, and the role of fiber architecture and ply layup are discussed. Three polymer systems, polycarbosilanes, polysilazanes, and polysilsesquioxanes, are compared as candidate ceramic matrix precursors.

  11. Rare Earth Aluminophosphosilicate Glass Precursors for Ceramic-Matrix-Composites (REAPS CMC’s)

    Science.gov (United States)

    2008-07-11

    translucent glasses and glass- ceramic composites via hot pressing at relatively low...sol-gel mixing on mullite microstructure and phase equilibria in the alpha -alumina- silica system. J. Am. Ceram . Soc, 1987. 70(10): p. 704-7. 15...Non- Cryst. Solids, 1988.100(1-3): p. 93-114. 18. Hoffman, D.W., R. Roy, and S. Komarneni, Diphasic xerogels, a new class of materials: phases in the system alumina- silica . J. Am. Ceram . Soc, 1984. 67(7): p. 468-71.

  12. CMC Technology Advancements for Gas Turbine Engine Applications

    Science.gov (United States)

    Grady, Joseph E.

    2013-01-01

    CMC research at NASA Glenn is focused on aircraft propulsion applications. The objective is to enable reduced engine emissions and fuel consumption for more environmentally friendly aircraft. Engine system studies show that incorporation of ceramic composites into turbine engines will enable significant reductions in emissions and fuel burn due to increased engine efficiency resulting from reduced cooling requirements for hot section components. This presentation will describe recent progress and challenges in developing fiber and matrix constituents for 2700 F CMC turbine applications. In addition, ongoing research in the development of durable environmental barrier coatings, ceramic joining integration technologies and life prediction methods for CMC engine components will be reviewed.

  13. Multi-Directional Composite Cylinders Assemblage Module for Physics-Based CMC Durability Modeling Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Compared to superalloys, ceramic matrix composites (CMCs) offer reduced weight and superior specific properties at elevated temperatures. However, CMCs are prone to...

  14. Surface chemistry of Nextel-720, alumina and Nextel-720/alumina ceramic matrix composite (CMC) using XPS A tool for nano-spectroscopy

    Science.gov (United States)

    Wannaparhun, S.; Seal, S.; Desai, V.

    2002-01-01

    Oxide-based ceramic matrix composites (CMCs) are prime candidates for high temperature turbine applications. Increasing demand of CMCs necessitates the development of quality monitoring procedures. Sol-gel derived Nextel-720 fiber/alumina matrix CMC is one of the potential candidate material for land-based gas turbine applications. X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) were utilized to investigate any surface/interface chemical alteration of the Nextel-720 fiber reinforcement and the alumina matrix during fabrication. The calculated XPS spectra of the composite were obtained by simply adding the spectra of the as-received Nextel-720 fiber and the alumina matrix. The calculated XPS spectra and the acquired XPS Al(2p), Si(2p 3), and O(1s) spectra from the as-received materials were compared using a superimposition method to investigate any chemical alteration during composite fabrication for quality control measures. This paper is aimed to serve as a reference for future XPS studies of CMCs exposed to aggressive turbine environments.

  15. Carboxymethyl cellulose (CMC)-loaded Co-Cu doped manganese ferrite nanorods as a new dual-modal simultaneous contrast agent for magnetic resonance imaging and nanocarrier for drug delivery system

    Science.gov (United States)

    Abbasi Pour, Sajjad; Shaterian, Hamid Reza; Afradi, Mojgan; Yazdani-Elah-Abadi, Afshin

    2017-09-01

    We synthesized Co0.25Cu0.25Mn0.5Fe2O4@CMC (CCMFe2O4@CMC) nanorods as a new dual-modal simultaneous for magnetic resonance imaging contrast agent and nanocarrier for drug delivery system. Impact of CCMFe2O4@CMC nanorods were investigated on the longitudinal (T1), transverse (T2) and transverse (T2∗) relaxation times for in vitro MRI contrast agent in water and also for drug delivery system, L-dopa was coated on CCMFe2O4@CMC nanorods and then in vitro drug release test was carried out at three PHs values and different temperatures. In vitro MR imaging demonstrated that r2 value of CCMFe2O4@CMC nanorods is 138.33 mM-1 s-1, CCMFe2O4@CMC is useful as T2 contrast agent relative to other T2 contrast agants. In vitro drug release test shows the amount of released L-dopa from CCMFe2O4@CMC nanorods at medium with pH = 1.2 is more than pH = 5.3 and 7.4.

  16. New method of screening allergenic components from Shuanghuanglian injection: with RBL-2H3/CMC model online HPLC/MS system.

    Science.gov (United States)

    Han, Shengli; Zhang, Tao; Huang, Jing; Cui, Ronghua; He, Langchong

    2014-01-01

    Shuanghuanglian (SHL) injection is a traditional Chinese medicine (TCM) injection widely used in China to treat influenza, tonsillitis, bronchitis, and faucitis. Adverse drug reactions (ADR) of SHL injection, majorly manifested as allergic reactions, were among the leading causes of death from TCM injection. In this study, an RBL-2H3/CMC online LC/MS system was established to screen and identify allergenic components in SHL injection, by which Baicalin was identified as a potential allergenic component. Allergenic activities of baicalin were investigated in RBL-2H3 cell degranulation and β-hexosaminidase release tests in vitro. Our results showed that baicalin dose-dependently induced RBL-2H3 cell degranulation and β-hexosaminidase release in the range of 0-50μg/ml. The RBL-2H3/CMC online LC/MS system developed in this study may potentially be used to screen allergenic components in other TCM injections. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Thin-walled reinforcement lattice structure for hollow CMC buckets

    Energy Technology Data Exchange (ETDEWEB)

    de Diego, Peter

    2017-06-27

    A hollow ceramic matrix composite (CMC) turbine bucket with an internal reinforcement lattice structure has improved vibration properties and stiffness. The lattice structure is formed of thin-walled plies made of CMC. The wall structures are arranged and located according to high stress areas within the hollow bucket. After the melt infiltration process, the mandrels melt away, leaving the wall structure to become the internal lattice reinforcement structure of the bucket.

  18. The Effect of Fiber Architecture on Matrix Cracking in Sic/sic Cmc's

    Science.gov (United States)

    Morscher, Gregory N.

    2005-01-01

    Applications incorporating silicon carbide fiber reinforced silicon carbide matrix composites (CMC's) will require a wide range of fiber architectures in order to fabricate complex shape. The stress-strain response of a given SiC/SiC system for different architectures and orientations will be required in order to design and effectively life-model future components. The mechanism for non-linear stress-strain behavior in CMC's is the formation and propagation of bridged-matrix cracks throughout the composite. A considerable amount of understanding has been achieved for the stress-dependent matrix cracking behavior of SiC fiber reinforced SiC matrix systems containing melt-infiltrated Si. This presentation will outline the effect of 2D and 3D architectures and orientation on stress-dependent matrix-cracking and how this information can be used to model material behavior and serve as the starting point foe mechanistic-based life-models.

  19. Design of high performance CMC brake discs

    Energy Technology Data Exchange (ETDEWEB)

    Krenkel, W.; Henke, T. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Stuttgart (Germany)

    1999-03-01

    Ceramic matrix composite (CMC) materials based on 2D-carbon fibre preforms show high heat-absorption capacities and good tribological as well as thermomechanical properties. To take advantage of the full lightweight potential of these new materials in high performance automotive brake discs, the thermal conductivity transverse to the friction surface has to be high in order to reduce the surface temperature. Experimental tests showed, that lower surface temperatures prevent overheating of the brake`s periphery and stabilizes the friction behaviour. In this study different design approaches with improved transverse heat conductivity have been investigated by finite element analysis. C/C-SiC bolts as well as SiC coatings and combinations of them have been investigated and compared with an orthotropic brake disc, showing a reduction of temperature of up to 50%. Original sized brake discs with C/C-SiC have been manufactured and tested under real conditions which verified the calculations. Using only low-cost CMC materials and avoiding any additional processing steps, the potential of C/C-SiC brake discs are very attractive under tribological as well as under economical aspects. (orig.) 4 refs.

  20. Radiation synthesis of superabsorbent CMC based hydrogels for agriculture applications

    Energy Technology Data Exchange (ETDEWEB)

    Raafat, Amany I., E-mail: ismaelraafat_a@hotmail.com [Polymer Chemistry Department, National Center for Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo (Egypt); Eid, Mona; El-Arnaouty, Magda B. [Polymer Chemistry Department, National Center for Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo (Egypt)

    2012-07-15

    A series of superabsorbent hydrogel based on carboxymethylcellulose (CMC) and polyvinylpyrrolidone (PVP) crosslinked with gamma irradiation have been proposed for agriculture application. The effect of preparation conditions such as feed solution composition and absorbed irradiation dose on the gelation and swelling degree was evaluated. The structure and the morphology of the superabsorbent CMC/PVP hydrogel were characterized using Fourier transform infrared spectroscopy technique (FTIR), and scanning electron microscope (SEM). Effect of ionic strength and cationic and anionic kinds on the swelling behavior of the obtained hydrogel was investigated. Urea as an agrochemical model was loaded onto the obtained hydrogel to provide nitrogen (N) nutrients. The water retention capability and the urea release behavior of the CMC/PVP hydrogels were investigated. It was found that, the obtained CMC/PVP hydrogels have good swelling degree that greatly affected by its composition and absorbed dose. The swelling was also extremely sensitive to the ionic strength and cationic kind. Owing to its considerable slow urea release, good water retention capacity, being economical, and environment-friendly, it might be useful for its application in agriculture field.

  1. Fabrication and Testing of Ceramic Matrix Composite Rocket Propulsion Components

    Science.gov (United States)

    Effinger, M. R.; Clinton, R. C., Jr.; Dennis, J.; Elam, S.; Genge, G.; Eckel, A.; Jaskowiak, M. H.; Kiser, J. D.; Lang, J.

    2001-01-01

    NASA has established goals for Second and Third Generation Reusable Launch Vehicles. Emphasis has been placed on significantly improving safety and decreasing the cost of transporting payloads to orbit. Ceramic matrix composites (CMC) components are being developed by NASA to enable significant increases in safety and engineer performance, while reducing costs. The development of the following CMC components are being pursued by NASA: (1) Simplex CMC Blisk; (2) Cooled CMC Nozzle Ramps; (3) Cooled CMC Thrust Chambers; and (4) CMC Gas Generator. These development efforts are application oriented, but have a strong underpinning of fundamental understanding of processing-microstructure-property relationships relative to structural analyses, nondestructive characterization, and material behavior analysis at the coupon and component and system operation levels. As each effort matures, emphasis will be placed on optimizing and demonstrating material/component durability, ideally using a combined Building Block Approach and Build and Bust Approach.

  2. Performance and Durability of Environmental Barrier Coatings on SiC/SiC Ceramic Matrix Composites

    Science.gov (United States)

    Zhu, Dongming; Harder, Bryan; Bhatt, Ramakrishna

    2016-01-01

    This presentation highlights advanced environmental barrier coating (EBC) and SiC-SiC Ceramic Matrix Composites (CMC) systems for next generation turbine engines. The emphasis will be placed on fundamental coating and CMC property evaluations; and the integrated system performance and degradation mechanisms in simulated laboratory turbine engine testing environments. Long term durability tests in laser rig simulated high heat flux the rmomechanical creep and fatigue loading conditions will also be presented. The results can help improve the future EBC-CMC system designs, validating the advanced EBC-CMC technologies for hot section turbine engine applications.

  3. Evaluation of modified CMC and CMC-PVA as miscible polymer blend membranes for hepatocytes.

    Science.gov (United States)

    Koç, Aysel; Durkut, Serap; Elçin, A Eser; Tan, Erdal; Elçin, Y Murat

    2007-05-10

    CMC and CMC-PVA were blended either with type I collagen, BSA or CS to obtain biocompatible membranes for evaluation as potential hepatocyte culture substrates. Pure and modified forms of CMC showed distinct surface, mechanical, and cell attachment properties. While the hydrophilicity decreased, the mechanical stability and the porosity of CMC membranes increased after blending. Serum proteins were adsorbed by all types of membranes. Among eight membranes tested, collagen-modified CMC was found to be a suitable membrane material for hepatocyte culture, in terms of mechanical and cell interaction properties.

  4. Synthesis and characterization of CMC from water hyacinth for lithium-ion battery applications

    Science.gov (United States)

    Hidayat, Sahrul; Susanty, Riveli, Nowo; Suroto, Bambang Joko; Rahayu, Iman

    2018-02-01

    Recently, the most dominating power supply on the mobile electronics market are rechargeable Lithium-ion batteries. This is because of a higher energy density and longer lifetime compared to similar rechargeable battery systems. One of the components that determine the performance of a lithium ion battery is the binder material, whether at the anode or the cathode. In commercial batteries, the material used as the binder is Polyvinylidene Difluoride (PVDF), with n-methyl-2-phyrrolidone (NMP) as the solvent. Both are synthetic materials that are expensive, toxic and harmful to the environment. An alternative binder material for lithium-ion battery electrodes is CMC (carboxymethyl cellulose) in a water solvent. CMC is cheaper than PVDF, non-toxic and more environmental friendly. CMC can be synthesized from several types of plants, such as water hyacinth, which is a weed plant with high cellulose content. The synthesis of CMC consists of three main steps, namely 1) the isolation process from water hyacinth, 2) the alkalization and carboxymethylation process and 3) the purification process to obtain CMC in high purity. FTIR characterization of the CMC shows five region of absorption bands. The bands in the region 1330-1400 cm-1 are due to symmetrical deformations of CH2 and OH groups. The ether bonds in CMC occur in the fingerprint region of 1250-1060 cm-1. The presence of new and strong absorption band around 1600 cm-1 is confirmed to the stretching vibration of the carboxyl group (COO-), while the one around 1415 cm-1 is assigned to carboxyl groups as it salts. The broad absorption band above 3400 cm-1 is due to the stretching frequency of the hydroxyl group (-OH). Purity test on three samples (CMC mesh-100, CMC mesh-60 and CMC, mesh-40) gives purity values of 99.89%, 99.99% and 99.89%, respectively. This proves that CMC have actually been formed with high purity.

  5. CMC Research at NASA Glenn in 2017: Recent Progress and Plans

    Science.gov (United States)

    Grady, Joseph E.

    2017-01-01

    As part of NASA's Aeronautics research mission, Glenn Research Center has developed advanced constituents for 2700F CMC turbine engine applications. In this presentation, fiber and matrix development and characterization for SiCSiC composites will be reviewed and resulting improvements in CMC durability and mechanical properties will be summarized. Progress toward the development and validation of models predicting the effects of the engine environment on durability of CMC and Environmental Barrier Coatings will be summarized and plans for research and collaborations in 2017 will be summarized.

  6. Reliability and Creep/Fatigue Analysis of a CMC Component

    Science.gov (United States)

    Murthy, Pappu L. N.; Mital, Subodh K.; Gyekenyesi, John Z.; Gyekenyesi, John P.

    2007-01-01

    High temperature ceramic matrix composites (CMC) are being explored as viable candidate materials for hot section gas turbine components. These advanced composites can potentially lead to reduced weight and enable higher operating temperatures requiring less cooling; thus leading to increased engine efficiencies. There is a need for convenient design tools that can accommodate various loading conditions and material data with their associated uncertainties to estimate the minimum predicted life as well as the failure probabilities of a structural component. This paper presents a review of the life prediction and probabilistic analyses performed for a CMC turbine stator vane. A computer code, NASALife, is used to predict the life of a 2-D woven silicon carbide fiber reinforced silicon carbide matrix (SiC/SiC) turbine stator vane due to a mission cycle which induces low cycle fatigue and creep. The output from this program includes damage from creep loading, damage due to cyclic loading and the combined damage due to the given loading cycle. Results indicate that the trends predicted by NASALife are as expected for the loading conditions used for this study. In addition, a combination of woven composite micromechanics, finite element structural analysis and Fast Probability Integration (FPI) techniques has been used to evaluate the maximum stress and its probabilistic distribution in a CMC turbine stator vane. Input variables causing scatter are identified and ranked based upon their sensitivity magnitude. Results indicate that reducing the scatter in proportional limit strength of the vane material has the greatest effect in improving the overall reliability of the CMC vane.

  7. Preparation and characterization of NaCS-CMC/PDMDAAC capsules.

    Science.gov (United States)

    Chen, Guo; Yao, Shan-jing; Guan, Yi-xin; Lin, Dong-qiang

    2005-11-10

    A novel capsule system composed of sodium cellulose sulfate (NaCS), carboxymethyl cellulose (CMC) and poly[dimethyl(diallyl)ammonium chloride] (PDMDAAC) was prepared for improving the properties of NaCS/PDMDAAC capsules. The process parameters, such as CMC concentration (0, 2, 4, 6 and 8 g/L), NaCS concentration (20, 25, 30, 35 and 40 g/L), PDMDAAC concentration (20, 30, 40, 50, 60, 70 and 80 g/L), reaction time and temperature were investigated to understand their effects on the diameter, membrane thickness and mechanical strength of capsules. The optimum operation conditions for preparing NaCS-CMC/PDMDAAC capsules were determined as 6-8 g/L CMC, 35-40 g/L NaCS, 60 g/L PDMDAAC and polymerization for 30-40 min. Diffusion of substances with low molecular weight into capsules was investigated, and diffusion coefficients were calculated according to the developed model. The yeast of Candida krusei was chosen as representative cell to evaluate the effects of different cell loading on capsule mechanical strength. Meanwhile the encapsulated osmophilic C. krusei cells were cultured in 250 mL shaking flasks for 72 h to determine the cell leaking properties in short and long term.

  8. SYLRAMIC™ SiC fibers for CMC reinforcement

    Science.gov (United States)

    Jones, Richard E.; Petrak, Dan; Rabe, Jim; Szweda, Andy

    2000-12-01

    Dow Corning researchers developed SYLRAMIC SiC fiber specifically for use in ceramic-matrix composite (CMC) components for use in turbine engine hot sections where excellent thermal stability, high strength and high thermal conductivity are required. This is a stoichiometric SiC fiber with a high degree of crystallinity, high tensile strength, high tensile modulus and good thermal conductivity. Owing to the small diameter, this textile-grade fiber can be woven into 2-D and 3-D structures for CMC fabrication. These properties are also of high interest to the nuclear community. Some initial studies have shown that SYLRAMIC fiber shows very good dimensional stability in a neutron flux environment, which offers further encouragement. This paper will review the properties of SYLRAMIC SiC fiber and then present the properties of polymer impregnation and pyrolysis (PIP) processed CMC made with this fiber at Dow Corning. While these composites may not be directly applicable to applications of interest to this audience, we believe that the properties shown will give good evidence that the fiber should be suitable for high temperature structural applications in the nuclear arena.

  9. Viscoplastic properties of laponite-CMC mixes

    Directory of Open Access Journals (Sweden)

    Z. Tarhini

    2017-04-01

    Full Text Available In this dataset, 15 samples of laponite-CMC mixes were realized and their viscoplastic properties are determined. Rheological parameters are then expressed as a function of age and components concentrations.

  10. SiC-CMC-Zircaloy-4 Nuclear Fuel Cladding Performance during 4-Point Tubular Bend Testing

    Energy Technology Data Exchange (ETDEWEB)

    IJ van Rooyen; WR Lloyd; TL Trowbridge; SR Novascone; KM Wendt; SM Bragg-Sitton

    2013-09-01

    The U.S. Department of Energy Office of Nuclear Energy (DOE NE) established the Light Water Reactor Sustainability (LWRS) program to develop technologies and other solutions to improve the reliability, sustain the safety, and extend the life of current reactors. The Advanced LWR Nuclear Fuel Development Pathway in the LWRS program encompasses strategic research focused on improving reactor core economics and safety margins through the development of an advanced fuel cladding system. Recent investigations of potential options for “accident tolerant” nuclear fuel systems point to the potential benefits of silicon carbide (SiC) cladding. One of the proposed SiC-based fuel cladding designs being investigated incorporates a SiC ceramic matrix composite (CMC) as a structural material supplementing an internal Zircaloy-4 (Zr-4) liner tube, referred to as the hybrid clad design. Characterization of the advanced cladding designs will include a number of out-of-pile (nonnuclear) tests, followed by in-pile irradiation testing of the most promising designs. One of the out-of-pile characterization tests provides measurement of the mechanical properties of the cladding tube using four point bend testing. Although the material properties of the different subsystems (materials) will be determined separately, in this paper we present results of 4-point bending tests performed on fully assembled hybrid cladding tube mock-ups, an assembled Zr-4 cladding tube mock-up as a standard and initial testing results on bare SiC-CMC sleeves to assist in defining design parameters. The hybrid mock-up samples incorporated SiC-CMC sleeves fabricated with 7 polymer impregnation and pyrolysis (PIP) cycles. To provide comparative information; both 1- and 2-ply braided SiC-CMC sleeves were used in this development study. Preliminary stress simulations were performed using the BISON nuclear fuel performance code to show the stress distribution differences for varying lengths between loading points

  11. Creep, Fatigue and Fracture Behavior of Environmental Barrier Coating and SiC-SiC Ceramic Matrix Composite Systems: The Role of Environment Effects

    Science.gov (United States)

    Zhu, Dongming; Ghosn, Louis J.

    2015-01-01

    Advanced environmental barrier coating (EBC) systems for low emission SiCSiC CMC combustors and turbine airfoils have been developed to meet next generation engine emission and performance goals. This presentation will highlight the developments of NASAs current EBC system technologies for SiC-SiC ceramic matrix composite combustors and turbine airfoils, their performance evaluation and modeling progress towards improving the engine SiCSiC component temperature capability and long-term durability. Our emphasis has also been placed on the fundamental aspects of the EBC-CMC creep and fatigue behaviors, and their interactions with turbine engine oxidizing and moisture environments. The EBC-CMC environmental degradation and failure modes, under various simulated engine testing environments, in particular involving high heat flux, high pressure, high velocity combustion conditions, will be discussed aiming at quantifying the protective coating functions, performance and durability, and in conjunction with damage mechanics and fracture mechanics approaches.

  12. Evaluation of Ceramic Matrix Composite Technology for Aircraft Turbine Engine Applications

    Science.gov (United States)

    Halbig, Michael C.; Jaskowiak, Martha H.; Kiser, James D.; Zhu, Dongming

    2013-01-01

    The goals of the NASA Environmentally Responsible Aviation (ERA) Project are to reduce the NO(x) emissions, fuel burn, and noise from turbine engines. In order to help meet these goals, commercially-produced ceramic matrix composite (CMC) components and environmental barrier coatings (EBCs) are being evaluated as parts and panels. The components include a CMC combustor liner, a CMC high pressure turbine vane, and a CMC exhaust nozzle as well as advanced EBCs that are tailored to the operating conditions of the CMC combustor and vane. The CMC combustor (w/EBC) could provide 2700 F temperature capability with less component cooling requirements to allow for more efficient combustion and reductions in NOx emissions. The CMC vane (w/EBC) will also have temperature capability up to 2700 F and allow for reduced fuel burn. The CMC mixer nozzle will offer reduced weight and improved mixing efficiency to provide reduced fuel burn. The main objectives are to evaluate the manufacturability of the complex-shaped components and to evaluate their performance under simulated engine operating conditions. Progress in CMC component fabrication, evaluation, and testing is presented in which the goal is to advance from the proof of concept validation (TRL 3) to a system/subsystem or prototype demonstration in a relevant environment (TRL 6).

  13. Computer Mediated Communication (CMC e Second Life

    Directory of Open Access Journals (Sweden)

    Annalisa Boniello

    2013-03-01

    Full Text Available In questo contributo sono riportate alcune esperienze e sperimentazioni didattiche che descrivono occasioni di comunicazione formativa (Computer Mediated Communication – CMC attraverso ambienti 3D quali Second Life (SL. Sono inoltre evidenziati e descritti i principali strumenti di comunicazione in SL e il loro utilizzo.

  14. Synthesis and properties of carboxymethylcellulose (CMC) graft ...

    African Journals Online (AJOL)

    Novel biopolymer-based superabsorbent hydrogels were prepared by grafting crosslinked poly (N-vinyl pyrollidin and 2-Acrylamido-2-methyl propan sulfonic acid (PNVP-co-PAMPS) chains onto CMC backbones through a free radical polymerization method. A proposed mechanism for superabsorbent hydrogel formation ...

  15. Federal Aviation Administration (FAA airworthiness certification for ceramic matrix composite components in civil aircraft systems

    Directory of Open Access Journals (Sweden)

    Gonczy Stephen T.

    2015-01-01

    Full Text Available Ceramic matrix composites (CMCs are being designed and developed for engine and exhaust components in commercial aviation, because they offer higher temperature capabilities, weight savings, and improved durability compared to metals. The United States Federal Aviation Administration (FAA issues and enforces regulations and minimum standards covering the safe manufacture, operation, and maintenance of civil aircraft. As new materials, these ceramic composite components will have to meet the certification regulations of the FAA for “airworthiness”. The FAA certification process is defined in the Federal Aviation Regulations (Title 14 of the Code of Federal Regulations, FAA policy statements, orders, advisory circulars, technical standard orders, and FAA airworthiness directives. These regulations and documents provide the fundamental requirements and guidelines for design, testing, manufacture, quality assurance, registration, operation, inspection, maintenance, and repair of aircraft systems and parts. For metallic parts in aircraft, the FAA certification and compliance process is well-established for type and airworthiness certification, using ASTM and SAE standards, the MMPDS data handbook, and FAA advisory circulars. In a similar manner for polymer matrix composites (PMC, the PMC industry and the FAA have jointly developed and are refining parallel guidelines for polymer matrix composites (PMCs, using guidance in FAA circulars and the CMH-17 PMC handbook. These documents discuss design methods and codes, material testing, property data development, life/durability assessment, production processes, QA procedures, inspection methods, operational limits, and repairs for PMCs. For ceramic composites, the FAA and the CMC and aerospace community are working together (primarily through the CMH-17 CMC handbook to define and codify key design, production, and regulatory issues that have to be addressed in the certification of CMC components in

  16. Fabrication and Testing of Ceramic Matrix Composite Propulsion Components

    Science.gov (United States)

    Effinger, Michael R.; Clinton, R. G., Jr.; Dennis, Jay; Elam, Sandy; Genge, Gary; Eckel, Andy; Jaskowiak, Martha H.; Kiser, J. Douglas; Lang, Jerry

    2000-01-01

    A viewgraph presentation outlines NASA's goals for the Second and Third Generation Reusable Launch Vehicles, placing emphasis on improving safety and decreasing the cost of transporting payloads to orbit. The use of ceramic matrix composite (CMC) technology is discussed. The development of CMC components, such as the Simplex CMC Blisk, cooled CMC nozzle ramps, cooled CMC thrust chambers, and CMC gas generators, are described, including challenges, test results, and likely future developments.

  17. The dynamic magnetoviscoelastic properties of biomineralized (Fe3O4) PVP-CMC hydrogel

    Science.gov (United States)

    Ray, Ayan; Saha, Nabanita; Saha, Petr

    2017-05-01

    The Polyvinylpyrrolidone (PVP) and carboxymethylcellulose (CMC) based polymer matrix was used as a template for the preparation of magnetic hydrogel. This freshly prepared PVP-CMC hydrogel template was successfully mineralized by in situ synthesis of magnetic nanoparticles (Fe3O4) via chemical co-precipitation reaction using liquid diffusion method. The present study emphasizes on the rheological behavior of non-mineralized and mineralized PVP-CMC hydrogels. Scanning Electron Microscopy (SEM), transmission electron microscopy (TEM), X-ray Diffraction (XRD) pattern, Fourier transform infrared spectroscopy (FT-TR), Vibrating sample magnetometer (VSM) and dynamic magneto rheometer were used to study the morphological, physical, chemical and magnetic properties of nanoparticle (Fe3O4) filled PVP-CMC hydrogel respectively in order to monitor how Fe3O4 magnetic nanoparticles affects the mechanical properties of the hydrogel network. The storage (G') and loss (G") moduli with a complex viscosity of the system was measured using a parallel plate rheometer. Frequency and amplitude sweep with temperature variation was performed to determine the frequency and amplitude dependent magneto viscoelastic moduli for both hydrogel samples. A strong shear thinning effect was observed in both (non-mineralized and mineralized) PVP-CMC hydrogels, which confirm that Fe3O4 filled magnetic hydrogels, are pseudoplastic in nature. This Fe3O4 filled PVP-CMC hydrogel can be considered as stimuli-responsive soft matter that may be used as an actuator in medical devices.

  18. Life Prediction for a CMC Component Using the NASALIFE Computer Code

    Science.gov (United States)

    Gyekenyesi, John Z.; Murthy, Pappu L. N.; Mital, Subodh K.

    2005-01-01

    The computer code, NASALIFE, was used to provide estimates for life of an SiC/SiC stator vane under varying thermomechanical loading conditions. The primary intention of this effort is to show how the computer code NASALIFE can be used to provide reasonable estimates of life for practical propulsion system components made of advanced ceramic matrix composites (CMC). Simple loading conditions provided readily observable and acceptable life predictions. Varying the loading conditions such that low cycle fatigue and creep were affected independently provided expected trends in the results for life due to varying loads and life due to creep. Analysis was based on idealized empirical data for the 9/99 Melt Infiltrated SiC fiber reinforced SiC.

  19. FEAMAC-CARES Software Coupling Development Effort for CMC Stochastic-Strength-Based Damage Simulation

    Science.gov (United States)

    Nemeth, Noel N.; Bednarcyk, Brett A.; Pineda, Evan; Arnold, Steven; Mital, Subodh; Murthy, Pappu; Walton, Owen

    2015-01-01

    Reported here is a coupling of two NASA developed codes: CARES (Ceramics Analysis and Reliability Evaluation of Structures) with the MACGMC composite material analysis code. The resulting code is called FEAMACCARES and is constructed as an Abaqus finite element analysis UMAT (user defined material). Here we describe the FEAMACCARES code and an example problem (taken from the open literature) of a laminated CMC in off-axis loading is shown. FEAMACCARES performs stochastic-strength-based damage simulation response of a CMC under multiaxial loading using elastic stiffness reduction of the failed elements.

  20. The optimization of CMC concentration as graphite binder on the anode of LiFePO4 battery

    Science.gov (United States)

    Hidayat, S.; Cahyono, T.; Mindara, J. Y.; Riveli, N.; Alamsyah, W.; Rahayu, I.

    2017-05-01

    Recently, the most dominating power supply on the mobile electronics market are rechargeable Lithium-ion batteries. This is because of a higher energy density and a longer lifetime compared to similar rechargeable battery systems. Graphite is commonly used as anode material in the Lithium-ion batteries, because of its excellent electrochemical characteristics and low cost fabrication. In this paper, we reported the optimization of the concentration of the CMC (carboxymethyl cellulose), that acts as the binder for graphite anode. Based on our experimental results, the best composition of graphite : C : CMC is 90 : 8 : 2 in weight %. Anode with such composition has, based on SEM measurement, a relatively good surface morphology, while it also has relatively high conductivity, about 2.68 S/cm. The result of cyclic voltammogram with a scan rate of 10 mV/s in the voltage range of 0 to 1 Volt, shows the peak of reduction voltage at 0.85 Volts and the peak voltage of oxidation is at -1.5 Volt. The performance of the battery system with LiFePO4 set as the cathode, shows that the working voltage is about 2.67 Volts at 1 mA current-loading, with the efficiency around 47%.

  1. Development of the Virginia Tech Department of Geosciences MEDL-CMC

    Science.gov (United States)

    Glesener, G. B.

    2016-12-01

    In 2015 the Virginia Tech Department of Geosciences took a leading role in increasing the level of support for Geoscience instructors by investing in the development of the Geosciences Modeling and Educational Demonstrations Laboratory Curriculum Materials Center (MEDL-CMC). The MEDL-CMC is an innovative curriculum materials center designed to foster new collaborative teaching and learning environments by providing hands-on physical models combined with education technology for instructors and outreach coordinators. The mission of the MEDL-CMC is to provide advanced curriculum material resources for the purpose of increasing and sustaining high impact instructional capacity in STEM education for both formal and informal learning environments. This presentation describes the development methods being used to implement the MEDL-CMC. Major development methods include: (1) adopting a project management system to support collaborations with stakeholders, (2) using a diversified funding approach to achieve financial sustainability and the ability to evolve with the educational needs of the community, and (3) establishing a broad collection of systems-based physical analog models and data collection tools to support integrated sciences such as the geosciences. Discussion will focus on how these methods are used for achieving organizational capacity in the MEDL-CMC and on their intended role in reducing instructor workload in planning both classroom activities and research grant broader impacts.

  2. Experimental And Numerical Study Of CMC Leading Edges In Hypersonic Flows

    Science.gov (United States)

    Kuhn, Markus; Esser, Burkard; Gulhan, Ali; Dalenbring, Mats; Cavagna, Luca

    2011-05-01

    Future transportation concepts aim at high supersonic or hypersonic speeds, where the formerly sharp boundaries between aeronautic and aerospace applications become blurred. One of the major issues involved to high speed flight are extremely high aerothermal loads, which especially appear at the leading edges of the plane’s wings and at sharp edged air intake components of the propulsion system. As classical materials like metals or simple ceramics would thermally and structurally fail here, new materials have to be applied. In this context, lightweight ceramic matrix composites (CMC) seem to be prospective candidates as they are high-temperature resistant and offer low thermal expansion along with high specific strength at elevated temperature levels. A generic leading edge model with a ceramic wing assembly with a sweep back angle of 53° was designed, which allowed for easy leading edge sample integration of different CMC materials. The samples consisted of the materials C/C-SiC (non-oxide), OXIPOL and WHIPOX (both oxide) with a nose radius of 2 mm. In addition, a sharp edged C/C-SiC sample was prepared to investigate the nose radius influence. Overall, 13 thermocouples were installed inside the entire model to measure the temperature evolution at specific locations, whereby 5 thermocouples were placed inside the leading edge sample itself. In addition, non-intrusive techniques were applied for surface temperature measurements: An infrared camera was used to measure the surface temperature distribution and at specific spots, the surface temperature was also measured by pyrometers. Following, the model was investigated in DLR’s arc-heated facility L3K at a total enthalpy of 8.5 MJ/kg, Mach number of 7.8, different angles of attack and varying wing inclination angles. These experiments provide a sound basis for the simulation of aerothermally loaded CMC leading edge structures. Such fluid-structure coupled approaches have been performed by FOI, basing on a

  3. Environmental/Thermal Barrier Coatings for Ceramic Matrix Composites: Thermal Tradeoff Studies

    Science.gov (United States)

    Murthy, Pappu L. M.; Brewer, David; Shah, Ashwin R.

    2007-01-01

    Recent interest in environmental/thermal barrier coatings (EBC/TBCs) has prompted research to develop life-prediction methodologies for the coating systems of advanced high-temperature ceramic matrix composites (CMCs). Heat-transfer analysis of EBC/TBCs for CMCs is an essential part of the effort. It helps establish the resulting thermal profile through the thickness of the CMC that is protected by the EBC/TBC system. This report documents the results of a one-dimensional analysis of an advanced high-temperature CMC system protected with an EBC/TBC system. The one-dimensional analysis was used for tradeoff studies involving parametric variation of the conductivity; the thickness of the EBC/TBCs, bond coat, and CMC substrate; and the cooling requirements. The insight gained from the results will be used to configure a viable EBC/TBC system for CMC liners that meet the desired hot surface, cold surface, and substrate temperature requirements.

  4. Study on novel functional materials carboxymethyl cellulose lithium (CMC-Li) improve high-performance lithium-ion battery.

    Science.gov (United States)

    Qiu, Lei; Shao, Ziqiang; Xiang, Pan; Wang, Daxiong; Zhou, Zhenwen; Wang, Feijun; Wang, Wenjun; Wang, Jianquan

    2014-09-22

    Novel cellulose derivative CMC-Li was synthesized by cotton as raw material. The mechanism of the CMC-Li modified electrode materials by electrospinning was reported. CMC-Li/lithium iron phosphate (LiFePO4, LFP) composite fiber coated with LFP and CMC-Li nanofibers was successfully obtained by electrospinning. Then, CMC-Li/LFP nano-composite fiber was carbonized under nitrogen at a high temperature formed CNF/LFP/Li (CLL) composite nanofibers as cathode material. It can increase the contents of Li+, and improving the diffusion efficiency and specific capacity. The battery with CLL as cathode material retained close to 100% of initial reversible capacity after 200 cycles at 168 mAh g(-1), which was nearly the theoretical specific capacity of LFP. The cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD) and scanning electron microscope (SEM) were characterizing material performance. The batteries have good electrochemical property, outstanding pollution-free, excellent stability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. A homogenous CS/NaCMC/n-HA polyelectrolyte complex membrane prepared by gradual electrostatic assembling.

    Science.gov (United States)

    Jiang, Hong; Zuo, Yi; Cheng, Lin; Wang, Hongli; Gu, Aiqun; Li, Yubao

    2011-02-01

    A homogenous membrane composed of chitosan (CS), sodium carboxymethyl cellulose (NaCMC) and nano hydroxyapatite (n-HA) was prepared by a gradual electrostatic assembling (GEA) method. The physical and chemical properties of the membranes with different n-HA contents and CS/NaCMC ratios were characterized by Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and mechanical test. The schematic formation mechanism of the membrane was discussed. The results show that GEA is an effective method to prepare the polyelectrolyte complex (PEC) membrane, in which oppositely charged CS-NaCMC polysaccharides can assemble mildly and gradually through electrostatic interaction to form the membrane framework, while the filled n-HA crystals can regulate the structure stability of the composite membrane. The optimum preparation condition for the PEC membrane can be fixed to a content of 60 wt% n-HA, an equivalent amount of CS to NaCMC and a drying temperature of 60°C. The PEC membrane may have good prospect for guided bone regeneration.

  6. Compositional analysis for linear systems

    NARCIS (Netherlands)

    Kerber, Florian; Schaft, Arjan van der

    2010-01-01

    Compositional analysis techniques such as assume-guarantee reasoning are frequently used in computer science to validate the design of complex process models. Since many engineering systems are built modularly from interconnections of components, the resulting mathematical models can be arbitrarily

  7. Development and Property Evaluation of Selected HfO2-Silicon and Rare Earth-Silicon Based Bond Coats and Environmental Barrier Coating Systems for SiC/SiC Ceramic Matrix Composites

    Science.gov (United States)

    Zhu, Dongming

    2016-01-01

    Ceramic environmental barrier coatings (EBC) and SiC/SiC ceramic matrix composites (CMCs) will play a crucial role in future aircraft propulsion systems because of their ability to significantly increase engine operating temperatures, improve component durability, reduce engine weight and cooling requirements. Advanced EBC systems for SiC/SiC CMC turbine and combustor hot section components are currently being developed to meet future turbine engine emission and performance goals. One of the significant material development challenges for the high temperature CMC components is to develop prime-reliant, high strength and high temperature capable environmental barrier coating bond coat systems, since the current silicon bond coat cannot meet the advanced EBC-CMC temperature and stability requirements. In this paper, advanced NASA HfO2-Si and rare earth Si based EBC bond coat EBC systems for SiC/SiC CMC combustor and turbine airfoil applications are investigated. High temperature properties of the advanced EBC systems, including the strength, fracture toughness, creep and oxidation resistance have been studied and summarized. The advanced NASA EBC systems showed some promise to achieve 1500C temperature capability, helping enable next generation turbine engines with significantly improved engine component temperature capability and durability.

  8. The Development of Environmental Barrier Coating Systems for SiC-SiC Ceramic Matrix Composites: Environment Effects on the Creep and Fatigue Resistance

    Science.gov (United States)

    Zhu, Dongming; Ghosn, Louis J.

    2014-01-01

    Topics covered include: Environmental barrier coating system development: needs, challenges and limitations; Advanced environmental barrier coating systems (EBCs) for CMC airfoils and combustors; NASA EBC systems and material system evolutions, Current turbine and combustor EBC coating emphases, Advanced development, processing, testing and modeling, EBC and EBC bond coats: recent advances; Design tool and life prediction of coated CMC components; Advanced CMC-EBC rig demonstrations; Summary and future directions.

  9. Quantum correlations in composite systems

    Science.gov (United States)

    Sperling, J.; Agudelo, E.; Walmsley, I. A.; Vogel, W.

    2017-07-01

    We study emerging notions of quantum correlations in compound systems. Based on different definitions of quantumness in individual subsystems, we investigate how they extend to the joint description of a composite system. Especially, we study the bipartite case and the connection of two typically applied and distinctively different concepts of nonclassicality in quantum optics and quantum information. Our investigation includes the representation of correlated states in terms of quasiprobability matrices, a comparative study of joint and conditional quantum correlations, and an entanglement characterization. It is, for example, shown that our composition approach always includes entanglement as one form of quantum correlations. Yet, other forms of quantum correlations can also occur without entanglement. Finally, we give an outlook towards multimode systems and temporal correlations.

  10. Carboxymethyl Cellulose (CMC Preparation from Mixed Office Wastepaper Deinked and Bleached Bagasse pulps: Characterization and Comparison

    Directory of Open Access Journals (Sweden)

    hasan mehdikhani

    2016-12-01

    Full Text Available Carboxymethyl cellulose (CMC, one of the most important cellulose derivatives, is widely and increasingly used in industries as emulsifier, stabilizer, disperser, thickener, and gelling agent. The main raw material of the cellulose derivative is cellulose from wood and cotton linter. However, lack of the fiber resources, especially in Iran, gradually grown interest on other available fiber resources such as agricultural waste and recycled fibers, as alternative cellulose resources. Bagasse pulp as a non-wood fiber and mixed office wastepaper deinked pulp as a recycled fiber were carboxymethylated in aqueous alkaline medium using mono chloro acetic acid (MCA as etherifying agent under identical conditions. Then, this paper explores the production feasibility of carboxymethylcellulose (CMC from the unusual pulps combined with the comparison. The chemical composition of the pulps were determined; include α-cellulose, hemicellulose, lignin, extractives and ash content, water retention value, intrinsic viscosity, carboxyl group and pH. α-cellulose content as the most important character of the derivatization was 84.66% in DIP and 71.33% in bagasse pulp. DIP non-polysaccharide compound (lignin, Ext. and ash was 5.92% compared to 2.36% for bagasse pulp. Cellulose carboxymethylated were done and the degree of substitution (DS, viscosity, purity, pH and yield of the prepared CMC was also determined and found to be dependent upon the source of the cellulose pulp. Viscosity and purity were higher in CMC produced from DIP (981 cPs and 93%, resp. compared to the bagasse pulp (680 cPs and 87.33% resp., which is attributed to its originally higher α-cellulose content. Yield and D.S were higher in CMC prepared from bagasse (168.8% and 0.57 resp. compared to DIP (155% and 0.45 resp., which are originated from lower crystallinity and molecular mass compound in bagasse, resulted in higher substitution of carboxymethyl groups.

  11. Melt Infiltrated Ceramic Composites (Hipercomp) for Gas Turbine Engine Applications

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Corman; Krishan Luthra

    2005-09-30

    This report covers work performed under the Continuous Fiber Ceramic Composites (CFCC) program by GE Global Research and its partners from 1994 through 2005. The processing of prepreg-derived, melt infiltrated (MI) composite systems based on monofilament and multifilament tow SiC fibers is described. Extensive mechanical and environmental exposure characterizations were performed on these systems, as well as on competing Ceramic Matrix Composite (CMC) systems. Although current monofilament SiC fibers have inherent oxidative stability limitations due to their carbon surface coatings, the MI CMC system based on multifilament tow (Hi-Nicalon ) proved to have excellent mechanical, thermal and time-dependent properties. The materials database generated from the material testing was used to design turbine hot gas path components, namely the shroud and combustor liner, utilizing the CMC materials. The feasibility of using such MI CMC materials in gas turbine engines was demonstrated via combustion rig testing of turbine shrouds and combustor liners, and through field engine tests of shrouds in a 2MW engine for >1000 hours. A unique combustion test facility was also developed that allowed coupons of the CMC materials to be exposed to high-pressure, high-velocity combustion gas environments for times up to {approx}4000 hours.

  12. Microstructure Evolution and Durability of Advanced Environmental Barrier Coating Systems for SiC/SiC Ceramic Matrix Composites

    Science.gov (United States)

    Zhu, Dongming; Evans, Laura J.; McCue, Terry R.; Harder, Bryan

    2016-01-01

    Environmental barrier coated SiC-SiC ceramic matrix composites (CMCs) systems will play a crucial role in next generation turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures with improved efficiency, reduce engine weight and cooling requirements. Advanced HfO2 and rare earth silicate environmental barrier coatings (EBCs), along with multicomponent hafnium and rare earth silicide EBC bond coats have been developed. The coating degradation mechanisms in the laboratory simulated engine thermal cycling, and fatigue-creep operating environments are also being investigated. This paper will focus on the microstructural and compositional evolutions of an advanced environmental barrier coating system on a SiC-SiC CMC substrate during the high temperature simulated durability tests, by using a Field Emission Gun Scanning Electron Microscopy, Energy Dispersive Spectroscopy (EDS) and Wavelength Dispersive Spectroscopy (WDS). The effects of Calcium-Magnesium-Alumino-Silicate (CMAS) from road sand or volcano-ash deposits on the degradation mechanisms of the environmental barrier coating systems will also be discussed. The detailed analysis results help understand the EBC-CMC system performance, aiming at the durability improvements to achieve more robust, prime-reliant environmental barrier coatings.

  13. PLANETESIMAL COMPOSITIONS IN EXOPLANET SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Torrence V. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Mousis, Olivier [Observatoire THETA, Institut UTINAM, UMR 6213 CNRS, Universite de Franche-Comte, BP 1615, F-25010 Besancon Cedex (France); Lunine, Jonathan I. [Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States); Madhusudhan, Nikku, E-mail: torrence.v.johnson@jpl.nasa.gov [Yale Center for Astronomy and Astrophysics, Department of Physics, Yale University, New Haven, CT 06511 (United States)

    2012-10-01

    We have used recent surveys of the composition of exoplanet host stars to investigate the expected composition of condensed material in planetesimals formed beyond the snow line in the circumstellar nebulae of these systems. Of the major solid-forming elements, C and O abundances (and particularly the C/O abundance ratio) strongly affect the amounts of volatile ices and refractory phases in icy planetesimals formed in these systems. This results from these elements' effects on the partitioning of O among gas, refractory solid and ice phases in the final condensate. The calculations use a self-consistent model for the condensation sequence of volatile ices from the nebula gas after refractory (silicate and metal) phases have condensed. The resultant mass fractions (compared to the total condensate) of refractory phases and ices were calculated for a range of nebular temperature structures and redox conditions. Planetesimals in systems with sub-solar C/O should be water ice-rich, with lower than solar mass fractions of refractory materials, while in super-solar C/O systems planetesimals should have significantly higher mass fractions of refractories, in some cases having little or no water ice. C-bearing volatile ices and clathrates also become increasingly important with increasing C/O depending on the assumed nebular temperatures. These compositional variations in early condensates in the outer portions of the nebula will be significant for the equivalent of the Kuiper Belt in these systems, icy satellites of giant planets, and the enrichment (over stellar values) of volatiles and heavy elements in giant planet atmospheres.

  14. Improvement on filterability in the aerobic treatment of carboxymethyl cellulose (CMC) wastewater

    OpenAIRE

    Qing Pei Ye; Hui Chen Dong; Ming Zhou Gong; Qin Lu; Qiang Ma Ji

    2014-01-01

    CMC is chemically modified from natural cellulose and widely applied in various industries. CMC wastewater consists mainly of sodium glycolate, sodium chloride and water. With extremely high COD and salinity, high concentration CMC wastewater can’t be biologically treated, but with COD and salinity around 15000 mg/L and 30000 mg/L respectively, low concentration CMC wastewater can be aerobically treated. In a CMC factory, the treatment of low concentration ...

  15. The Conserved Mitochondrial Twin Cx9C Protein Cmc2 Is a Cmc1 Homologue Essential for Cytochrome c Oxidase Biogenesis*

    OpenAIRE

    Horn, Darryl; Zhou, Wen; Trevisson, Eva; Al-Ali, Hassan; Harris, Thomas K.; Salviati, Leonardo; Barrientos, Antoni

    2010-01-01

    Mitochondrial copper metabolism and delivery to cytochrome c oxidase and mitochondrially localized CuZn-superoxide dismutase (Sod1) requires a growing number of intermembrane space proteins containing a twin Cx9C motif. Among them, Cmc1 was recently identified by our group. Here we describe another conserved mitochondrial metallochaperone-like protein, Cmc2, a close homologue of Cmc1, whose function affects both cytochrome c oxidase and Sod1. In the yeast Saccharomyces cerevisiae, Cmc2 locali...

  16. Standard Biocompatibility Studies Do Not Predict All Effects of PVA/CMC Anti-Adhesive Gel in vivo.

    Science.gov (United States)

    Freytag, Christiane; Odermatt, Erich K

    2016-01-01

    PVA/CMC (polyvinyl alcohol/carboxymethyl cellulose) hydrogel fulfills various physiochemical properties required for an adhesion barrier and has shown good anti-adhesion properties in previous in vivo studies. In this investigation, we assessed the in vitro and in vivo biocompatibility of PVA/CMC gel and compared this to the functionality and promotion of wound healing for two surgical indications. Standardized ISO10993 in vitro and in vivo biocompatibility studies, comprising cytotoxicity, genotoxicity, acute systemic toxicity, delayed contact and maximization sensitization test, intracutaneous reactivity and local muscle implantation, were performed on PVA/CMC gel. In the functional studies, PVA/CMC gel was applied - on the one hand - to a rabbit abdominal wall model enforced with a polypropylene mesh for testing the anti-adhesion properties and - on the other hand - to an end- to-end anastomosis model that was selected for surveying potential influences of different dosages of PVA/CMC gel on anastomotic wound healing. The ISO10993 methods indicated generally good biocompatibility properties, such as the absence of cytotoxic and mutagenic effects as well as no signs of systemic toxicity and sensitization potentials. No irritation effects were observed after the intracutaneous injection of lipophilic PVA/CMC sesame oil extract. However, the injection of hydrophilic PVA/CMC physiologic saline extract induced slight irritation. Following rabbit muscle implantation of the PVA membrane for 2, 4, 12, 26 and 52 weeks, a slight irritant effect was observed at 12 weeks due to the peak of phagocytosis. In the functionality tests, PVA/CMC gel showed good anti-adhesive effects in the abdominal wall model enforced with the mesh, with significantly lower and less tense adhesions compared to the untreated control. However, moderate signs of inflammation, especially in the spleen were observed after the intra-abdominal implantation of 3.3 ml PVA/CMC gel per kg body weight. In

  17. Overview of C/C-SiC Composite Development for the Orion Launch Abort System

    Science.gov (United States)

    Allen, Lee R.; Valentine, Peter G.; Schofield, Elizabeth S.; Beshears, Ronald D.; Coston, James E.

    2012-01-01

    Past and present efforts by the authors to further understanding of the ceramic matrix composite (CMC) material used in the valve components of the Orion Launch Abort System (LAS) Attitude Control Motor (ACM) will be presented. The LAS is designed to quickly lift the Orion Crew Exploration Vehicle (CEV) away from its launch vehicle in emergency abort scenarios. The ACM is a solid rocket motor which utilizes eight throttleable nozzles to maintain proper orientation of the CEV during abort operations. Launch abort systems have not been available for use by NASA on manned launches since the last Apollo ]Saturn launch in 1975. The CMC material, carbon-carbon/silicon-carbide (C/C-SiC), is manufactured by Fiber Materials, Inc. and consists of a rigid 4-directional carbon-fiber tow weave reinforced with a mixed carbon plus SiC matrix. Several valve and full system (8-valve) static motor tests have been conducted by the motor vendor. The culmination of these tests was the successful flight test of the Orion LAS Pad Abort One (PA ]1) vehicle on May 6, 2010. Due to the fast pace of the LAS development program, NASA Marshall Space Flight Center assisted the LAS community by performing a series of material and component evaluations using fired hardware from valve and full ]system development motor tests, and from the PA-1 flight ACM motor. Information will be presented on the structure of the C/C-SiC material, as well as the efficacy of various non ]destructive evaluation (NDE) techniques, including but not limited to: radiography, computed tomography, nanofocus computed tomography, and X-ray transmission microscopy. Examinations of the microstructure of the material via scanning electron microscopy and energy dispersive spectroscopy will also be discussed. The findings resulting from the subject effort are assisting the LAS Project in risk assessments and in possible modifications to the final ACM operational design.

  18. A distributed program composition system

    Science.gov (United States)

    Brown, Robert L.

    1989-01-01

    A graphical technique for creating distributed computer programs is investigated and a prototype implementation is described which serves as a testbed for the concepts. The type of programs under examination is restricted to those comprising relatively heavyweight parts that intercommunicate by passing messages of typed objects. Such programs are often presented visually as a directed graph with computer program parts as the nodes and communication channels as the edges. This class of programs, called parts-based programs, is not well supported by existing computer systems; much manual work is required to describe the program to the system, establish the communication paths, accommodate the heterogeneity of data types, and to locate the parts of the program on the various systems involved. The work described solves most of these problems by providing an interface for describing parts-based programs in this class in a way that closely models the way programmers think about them: using sketches of diagraphs. Program parts, the computational modes of the larger program system are categorized in libraries and are accessed with browsers. The process of programming has the programmer draw the program graph interactively. Heterogeneity is automatically accommodated by the insertion of type translators where necessary between the parts. Many decisions are necessary in the creation of a comprehensive tool for interactive creation of programs in this class. Possibilities are explored and the issues behind such decisions are presented. An approach to program composition is described, not a carefully implemented programming environment. However, a prototype implementation is described that can demonstrate the ideas presented.

  19. Melt Infiltrated Ceramic Matrix Composites for Shrouds and Combustor Liners of Advanced Industrial Gas Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Corman; Krishan Luthra; Jill Jonkowski; Joseph Mavec; Paul Bakke; Debbie Haught; Merrill Smith

    2011-01-07

    This report covers work performed under the Advanced Materials for Advanced Industrial Gas Turbines (AMAIGT) program by GE Global Research and its collaborators from 2000 through 2010. A first stage shroud for a 7FA-class gas turbine engine utilizing HiPerComp{reg_sign}* ceramic matrix composite (CMC) material was developed. The design, fabrication, rig testing and engine testing of this shroud system are described. Through two field engine tests, the latter of which is still in progress at a Jacksonville Electric Authority generating station, the robustness of the CMC material and the shroud system in general were demonstrated, with shrouds having accumulated nearly 7,000 hours of field engine testing at the conclusion of the program. During the latter test the engine performance benefits from utilizing CMC shrouds were verified. Similar development of a CMC combustor liner design for a 7FA-class engine is also described. The feasibility of using the HiPerComp{reg_sign} CMC material for combustor liner applications was demonstrated in a Solar Turbines Ceramic Stationary Gas Turbine (CSGT) engine test where the liner performed without incident for 12,822 hours. The deposition processes for applying environmental barrier coatings to the CMC components were also developed, and the performance of the coatings in the rig and engine tests is described.

  20. Development of Advanced Environmental Barrier Coatings for SiC/SiC Ceramic Matrix Composites: Path Toward 2700 F Temperature Capability and Beyond

    Science.gov (United States)

    Zhu, Dongming; Harder, Bryan; Hurst, Janet B.; Good, Brian; Costa, Gustavo; Bhatt, Ramakrishna T.; Fox, Dennis S.

    2017-01-01

    Advanced environmental barrier coating systems for SiC-SiC Ceramic Matrix Composite (CMC) turbine and combustor hot section components are currently being developed to meet future turbine engine emission and performance goals. One of the significant coating development challenges is to achieve prime-reliant environmental barrier coating systems to meet the future 2700F EBC-CMC temperature stability and environmental durability requirements. This presentation will emphasize recent NASA environmental barrier coating system testing and down-selects, particularly the development path and properties towards 2700-3000F durability goals by using NASA hafnium-hafnia-rare earth-silicon-silicate composition EBC systems for the SiC-SiC CMC turbine component applications. Advanced hafnium-based compositions for enabling next generation EBC and CMCs capabilities towards ultra-high temperature ceramic coating systems will also be briefly mentioned.

  1. Creep Behavior and Durability of Cracked CMC

    Science.gov (United States)

    Bhatt, R. T.; Fox, Dennis; Smith, Craig

    2015-01-01

    To understand failure mechanisms and durability of cracked Ceramic matrix composites (CMCs), Melt Infiltration (MI) SiCSiC composites with Sylramic-iBN fibers and full Chemical vapour infiltration SiCSiC composites with Sylramic-ion bombarded BN (iBN) and Hi-Nicalon -S fibers were pre-cracked between 150 to 200 megapascal and then creep and Sustained Peak Low Cycle Fatigue (SPLCF) tested at 13150 C at stress levels from 35 to 103 megapascal for up to 200 hours under furnace and burner rig conditions. In addition creep testing was also conducted on pre-cracked full Chemical vapour infiltration SiCSiC composites at 14500 C between 35 and 103 megapascal for up to 200 hours under furnace conditions. If the specimens survived the 200 hour durability tests, then they were tensile tested at room temperature to determine their residual tensile properties. The failed specimens were examined by Scanning electron microscope (SEM) to determine the failure modes and mechanisms. The influence of crack healing matrix, fiber types, crack density, testing modes and interface oxidation on durability of cracked Ceramic matrix composites (CMCs) will be discussed.

  2. Influence of Polyethylene Glycol (PEG in CMC-NH4BR Based Polymer Electrolytes: Conductivity and Electrical Study

    Directory of Open Access Journals (Sweden)

    Nur Khalidah Zainuddin

    2017-04-01

    Full Text Available The present work was carried with new type and promising polymer electrolytes system by development of carboxylmethylcellulose (CMC doped NH4Br and plasticized with polyethylene glycol (PEG. The sample was successfullyprepared via solution casting with no separation phase and good mechanical properties. The electrical conductivity andthermal conductivity of CMC-NH4Br-PEG based PEs system have been measured by the electrical impedancespectroscopy method in the temperature range of 303–373 K. The highest ionic conductivity gained is 2.48 x 10-3 Scm-1at ambient temperature for sample contain with 8 wt. % PEG. It can be concluded that the plasticized is accountable forthe conductance and assist to enhancing the ionic conductivity of the CMC-NH4Br-PEG electrolyte system. The addition of PEG to the CMC-based electrolyte can enhance towards the cation mobility which is turn increases ionic conductivity. The conductivity-temperature of plasticized BdPEs system was found obeys the Arrhenius relation where the ionic conductivity increases with temperature and activation energy for the ions hopping of the highest conducting PEs system only required small value to migrate. The electrical studies show a non-Debye behaviour of BdPEs based on the analyzed data using complex permittivity, ε* and complex electrical modulus, M* of the sample at different temperature.

  3. Performance of Edible Coatings from Carboxymethylcellulose(CMC ...

    African Journals Online (AJOL)

    Performance of Edible Coatings from Carboxymethylcellulose(CMC) and Corn Starch(CS) Incorporated with Moringa Oleifera Extract on Citrus Sinensis Stored at ... that polysaccharides coating from (CSME) and (CMCME) on orange fruits when compared to untreated in the following order: (CSME) > (CMCME) >Control in ...

  4. Environmental Stability and Oxidation Behavior of HfO2-Si and YbGd(O) Based Environmental Barrier Coating Systems for SiCSiC Ceramic Matrix Composites

    Science.gov (United States)

    Zhu, Dongming; Farmer, Serene; McCue, Terry R.; Harder, Bryan; Hurst, Janet B.

    2017-01-01

    Ceramic environmental barrier coatings (EBC) and SiCSiC ceramic matrix composites (CMCs) will play a crucial role in future aircraft propulsion systems because of their ability to significantly increase engine operating temperatures, improve component durability, reduce engine weight and cooling requirements. Advanced EBC systems for SiCSiC CMC turbine and combustor hot section components are currently being developed to meet future turbine engine emission and performance goals. One of the significant material development challenges for the high temperature CMC components is to develop prime-reliant, environmental durable environmental barrier coating systems. In this paper, the durability and performance of advanced Electron Beam-Physical Vapor Deposition (EB-PVD) NASA HfO2-Si and YbGdSi(O) EBC bond coat top coat systems for SiCSiC CMC have been summarized. The high temperature thermomechanical creep, fatigue and oxidation resistance have been investigated in the laboratory simulated high-heat-flux environmental test conditions. The advanced NASA EBC systems showed promise to achieve 1500C temperature capability, helping enable next generation turbine engines with significantly improved engine component temperature capability and durability.

  5. Investigation of MEBES 4500 system composite performance

    Science.gov (United States)

    DeWitt, Jim; Watson, Joe; Alexander, David W.; Cook, Allen; Gasiorek, Leonard; Mayse, Mark; Naber, Robert J.; Phillips, Wayne; Sauer, Charles A.

    1995-12-01

    MEBES systems are characterized by constituent error performance, whereas masks produced on pattern generators are characterized by composite error performance. System evaluation by constituent specification is notable for the ease with which system calibration can be obtained, monitored, and maintained. Constituent specifications need to be retained for these reasons. This work investigates the composite performance of a MEBES 4500 system when generating masks compared to system constituent performance. Masks with scan-centered and non-scan- centered patterns are characterized and compared with both MEBES-based MARKET metrology and independent tool-based metrology.

  6. Compositional Modelling of Stochastic Hybrid Systems

    NARCIS (Netherlands)

    Strubbe, S.N.

    2005-01-01

    In this thesis we present a modelling framework for compositional modelling of stochastic hybrid systems. Hybrid systems consist of a combination of continuous and discrete dynamics. The state space of a hybrid system is hybrid in the sense that it consists of a continuous component and a discrete

  7. An Update on Design Tools for Optimization of CMC 3D Fiber Architectures

    Science.gov (United States)

    Lang, J.; DiCarlo, J.

    2012-01-01

    Objective: Describe and up-date progress for NASA's efforts to develop 3D architectural design tools for CMC in general and for SIC/SiC composites in particular. Describe past and current sequential work efforts aimed at: Understanding key fiber and tow physical characteristics in conventional 2D and 3D woven architectures as revealed by microstructures in the literature. Developing an Excel program for down-selecting and predicting key geometric properties and resulting key fiber-controlled properties for various conventional 3D architectures. Developing a software tool for accurately visualizing all the key geometric details of conventional 3D architectures. Validating tools by visualizing and predicting the Internal geometry and key mechanical properties of a NASA SIC/SIC panel with a 3D orthogonal architecture. Applying the predictive and visualization tools toward advanced 3D orthogonal SiC/SIC composites, and combining them into a user-friendly software program.

  8. HLB (hydrophilic lipophilic balance), CMC (critical micelle concentration) and phase behavior as related to hydrophobe branching

    Energy Technology Data Exchange (ETDEWEB)

    Graciaa, A.; Barakat, Y.; El-Eary, M.; Fortney, L.; Schechter, R.S.

    1982-09-01

    Increased hydrophobe branching is employed to increase water solubility of surfactants. This is often considered synonymous with increasing surfactant HLB. When HLB is viewed in the context of the phase behavior of oil/water/surfactant systems, it is seen that increased branching favors partitioning into the oil phase, thus lowering surfactant HLB despite an experimentally observed increase in CMC. An alternative to HLB is proposed which defines a surfactant's properties based on the optimal alkane needed for the appropriate surfactant phase behavior. 23 references.

  9. Energy condensed packaged systems. Composition, production, properties

    OpenAIRE

    Igor L. Kovalenko; Vitaliy P. Kuprin; Dmytro V. Kiyaschenko

    2015-01-01

    In this paper it is presented the substantiation of choice of fuel phase composition and optimal technology of emulsion production on the basis of binary solution of ammonium and calcium nitrates, which provide the obtaining of energy condensed packaged systems with specified properties. The thermal decomposition of energy condensed systems on the basis of ammonium nitrate is investigated. It is shown that the fuel phase of emulsion systems should be based on esters of polyunsaturated acids o...

  10. Natural Composite Systems for Bioinspired Materials.

    Science.gov (United States)

    Frezzo, Joseph A; Montclare, Jin Kim

    2016-01-01

    From a relatively limited selection of base materials, nature has steered the development of truly remarkable materials. The simplest and often overlooked organisms have demonstrated the ability to manufacture multi-faceted, molecular-level hierarchical structures that combine mechanical properties rarely seen in synthetic materials. Indeed, these natural composite systems, composed of an array of intricately arranged and functionally relevant organic and inorganic substances serve as inspiration for materials design. A better understanding of these composite systems, specifically at the interface of the hetero-assemblies, would encourage faster development of environmentally friendly "green" materials with molecular level specificities.

  11. Cooled Ceramic Matrix Composite Propulsion Structures Demonstrated

    Science.gov (United States)

    Jaskowiak, Martha H.; Dickens, Kevin W.

    2005-01-01

    NASA's Next Generation Launch Technology (NGLT) Program has successfully demonstrated cooled ceramic matrix composite (CMC) technology in a scramjet engine test. This demonstration represented the world s largest cooled nonmetallic matrix composite panel fabricated for a scramjet engine and the first cooled nonmetallic composite to be tested in a scramjet facility. Lightweight, high-temperature, actively cooled structures have been identified as a key technology for enabling reliable and low-cost space access. Tradeoff studies have shown this to be the case for a variety of launch platforms, including rockets and hypersonic cruise vehicles. Actively cooled carbon and CMC structures may meet high-performance goals at significantly lower weight, while improving safety by operating with a higher margin between the design temperature and material upper-use temperature. Studies have shown that using actively cooled CMCs can reduce the weight of the cooled flow-path component from 4.5 to 1.6 lb/sq ft and the weight of the propulsion system s cooled surface area by more than 50 percent. This weight savings enables advanced concepts, increased payload, and increased range. The ability of the cooled CMC flow-path components to operate over 1000 F hotter than the state-of-the-art metallic concept adds system design flexibility to space-access vehicle concepts. Other potential system-level benefits include smaller fuel pumps, lower part count, lower cost, and increased operating margin.

  12. Overview of Cooperative Monitoring Concepts and the CMC

    Energy Technology Data Exchange (ETDEWEB)

    Biringer, Kent L.

    1999-05-14

    Cooperative monitoring holds the promise of utilizing many technologies from conflicts of the past to implement agreements of peace in the future. Important approaches to accomplish this are to develop the framework for assessing monitoring opportunities and to provide education and training on the technologies and experience available for sharing with others. The Cooperative Monitoring Center (CMC) at Sandia National Laboratories is working closely with agencies throughout the federal government, academics at home and abroad, and regional organizations to provide the technical tools needed to assess, design, analyze, and implement these cooperative agreements. In doing so, the goals of building regional confidence and increasing trust and communication can be furthered.

  13. Characterization of LWRS Hybrid SiC-CMC-Zircaloy-4 Fuel Cladding after Gamma Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Isabella J van Rooyen

    2012-09-01

    The purpose of the gamma irradiation tests conducted at the Idaho National Laboratory (INL) was to obtain a better understanding of chemical interactions and potential changes in microstructural properties of a mock-up hybrid nuclear fuel cladding rodlet design (unfueled) in a simulated PWR water environment under irradiation conditions. The hybrid fuel rodlet design is being investigated under the Light Water Reactor Sustainability (LWRS) program for further development and testing of one of the possible advanced LWR nuclear fuel cladding designs. The gamma irradiation tests were performed in preparation for neutron irradiation tests planned for a silicon carbide (SiC) ceramic matrix composite (CMC) zircaloy-4 (Zr-4) hybrid fuel rodlet that may be tested in the INL Advanced Test Reactor (ATR) if the design is selected for further development and testing

  14. Timber-concrete composite floor systems

    NARCIS (Netherlands)

    Linden, M.L.R. van der; Blass, H.J.

    1996-01-01

    Timber-concrete composite (tcc) beams may be used for the renovation of old timber floors. Although these systems are a simple and practical solution, they are not widely adopted. One of the reasons for this is the lack of uniform design mies. In this research programme shear tests on four different

  15. PENGARUH PENAMBAHAN KARBOKSIMETIL SELULOSA (CMC TERHADAP TINGKAT CROSSLINKING DAN KUAT TARIK PEO HIDROGEL FILM

    Directory of Open Access Journals (Sweden)

    Haryanto

    2018-10-01

    Full Text Available Penggunaan hidrogel film pada bidang kesehatan dan pertanian berkembang dengan pesat, hal ini di karenakan karakteristik istimewa dari hidrogel yang mampu menyerap air dan mempertahankan kandungan air didalamnya sehingga memiliki sifat lembut serta dapat dipakai pada aplikasi medis. Hidrogel film yang dibuat menggunakan bahan dasar polietilene oksida memiliki kekuatan mekanik yang rendah. Untuk itu perlu dikembangkan hidrogel film yang memiliki karakteristik mekanik yang lebih baik dengan menambahkan karboksi metil selulosa (cmc didalam larutan polietilen oksida. Berbagai komposisi larutan cmc/peo (5%, 10%, 15% dan 20% diradiasi dengan menggunakan sinar electron beam untuk mendapatkan jaringan network diantara polimer yang diradiasi. Kandungan cmc mempengaruhi berbagai karakteristik hidrogel film seperti fraksi gel, rasio swelling, sifat mekanik. Hasil penelitian menunjukkan bahwa pada penambahan cmc sampai dengan 10%, semakin tinggi kandungan cmc, maka tingkat kroslinking, kuat Tarik dan persen pemanjangan juga semakin naik. Sebaliknya semakin tinggi kandungan cmc, maka rasio swelling justru akan semakin menurun.

  16. Ceramic Matrix Composites for Rotorcraft Engines

    Science.gov (United States)

    Halbig, Michael C.

    2011-01-01

    Ceramic matrix composite (CMC) components are being developed for turbine engine applications. Compared to metallic components, the CMC components offer benefits of higher temperature capability and less cooling requirements which correlates to improved efficiency and reduced emissions. This presentation discusses a technology develop effort for overcoming challenges in fabricating a CMC vane for the high pressure turbine. The areas of technology development include small component fabrication, ceramic joining and integration, material and component testing and characterization, and design and analysis of concept components.

  17. Apparatus and method to reduce wear and friction between CMC-to-metal attachment and interface

    Science.gov (United States)

    Cairo, Ronald Ralph; Parolini, Jason Robert; Delvaux, John McConnell

    2016-11-22

    An apparatus to reduce wear and friction between CMC-to-metal attachment and interface, including a metal layer configured for insertion between a surface interface between a CMC component and a metal component. The surface interface of the metal layer is compliant relative to asperities of the surface interface of the CMC component. A coefficient of friction between the surface interface of the CMC component and the metal component is about 1.0 or less at an operating temperature between about 300.degree. C. to about 325.degree. C. and a limiting temperature of the metal component.

  18. Application of CMC as Thickener on Nanoemulsions Based on Olive Oil: Physical Properties and Stability

    Directory of Open Access Journals (Sweden)

    C. Arancibia

    2016-01-01

    Full Text Available Carboxymethyl cellulose (CMC is a hydrocolloid with surface activity that could act as emulsifiers in oil-in-water emulsions; however the principal role is that it acts as structuring, thickening, or gelling agent in the aqueous phase. This study aims to evaluate the application of CMC as thickener into nanoemulsions based on olive oil and their influence on particle characteristics, flow behavior, and color. Four nanoemulsions with different oil (5% and 15% w/w olive oil and CMC (0.5% and 0.75% w/w concentration and two control samples without CMC added were prepared using Tween 80 as emulsifier. All physical properties studied on nanoemulsions were depending on both oil and CMC concentration. In general, z-average particle size varied among 107–121 nm and those samples with 5% oil and CMC were the most polydisperse. The addition of CMC increased anionic charge of nanoemulsions obtaining zeta potential values among −41 and −55 mV. The oil concentration increased both consistency and pseudoplasticity of samples, although samples were more stable to gravitational separation at the highest CMC concentration. Color of nanoemulsions was affected principally by the oil concentration. Finally, the results showed that CMC could be applied in nanoemulsions as thickener increasing their physical stability although modifying their physical properties.

  19. Energy condensed packaged systems. Composition, production, properties

    Directory of Open Access Journals (Sweden)

    Igor L. Kovalenko

    2015-03-01

    Full Text Available In this paper it is presented the substantiation of choice of fuel phase composition and optimal technology of emulsion production on the basis of binary solution of ammonium and calcium nitrates, which provide the obtaining of energy condensed packaged systems with specified properties. The thermal decomposition of energy condensed systems on the basis of ammonium nitrate is investigated. It is shown that the fuel phase of emulsion systems should be based on esters of polyunsaturated acids or on combinations thereof with petroleum products. And ceresin or petroleum wax can be used as the structuring additive. The influence of the technology of energy condensed systems production on the physicochemical and detonation parameters of emulsion explosives is considered. It is shown the possibility of obtaining of emulsion systems with dispersion of 1.3...1.8 microns and viscosity higher than 103 Pa∙s in the apparatus of original design. The sensitizing effect of chlorinated paraffin CP-470 on the thermolysis of energy condensed emulsion system is shown. The composition and production technology of energy condensed packaged emulsion systems of mark Ukrainit-P for underground mining in mines not dangerous on gas and dust are developed.

  20. Development and Performance Evaluations of HfO2-Si and Rare Earth-Si Based Environmental Barrier Bond Coat Systems for SiC/SiC Ceramic Matrix Composites

    Science.gov (United States)

    Zhu, Dongming

    2014-01-01

    Ceramic environmental barrier coatings (EBC) and SiCSiC ceramic matrix composites (CMCs) will play a crucial role in future aircraft propulsion systems because of their ability to significantly increase engine operating temperatures, improve component durability, reduce engine weight and cooling requirements. Advanced EBC systems for SiCSiC CMC turbine and combustor hot section components are currently being developed to meet future turbine engine emission and performance goals. One of the significant material development challenges for the high temperature CMC components is to develop prime-reliant, high strength and high temperature capable environmental barrier coating bond coat systems, since the current silicon bond coat cannot meet the advanced EBC-CMC temperature and stability requirements. In this paper, advanced NASA HfO2-Si based EBC bond coat systems for SiCSiC CMC combustor and turbine airfoil applications are investigated. The coating design approach and stability requirements are specifically emphasized, with the development and implementation focusing on Plasma Sprayed (PS) and Electron Beam-Physic Vapor Deposited (EB-PVD) coating systems and the composition optimizations. High temperature properties of the HfO2-Si based bond coat systems, including the strength, fracture toughness, creep resistance, and oxidation resistance were evaluated in the temperature range of 1200 to 1500 C. Thermal gradient heat flux low cycle fatigue and furnace cyclic oxidation durability tests were also performed at temperatures up to 1500 C. The coating strength improvements, degradation and failure modes of the environmental barrier coating bond coat systems on SiCSiC CMCs tested in simulated stress-environment interactions are briefly discussed and supported by modeling. The performance enhancements of the HfO2-Si bond coat systems with rare earth element dopants and rare earth-silicon based bond coats are also highlighted. The advanced bond coat systems, when

  1. Composite material systems for hydrogen management

    Science.gov (United States)

    Pangborn, R. N.; Queeney, R. A.

    1991-01-01

    The task of managing hydrogen entry into elevated temperature structural materials employed in turbomachinery is a critical engineering area for propulsion systems employing hydrogen or decomposable hydrocarbons as fuel. Extant structural materials, such as the Inconel series, are embrittled by the ingress of hydrogen in service, leading to a loss of endurance and general deterioration of load-bearing dependability. Although the development of hydrogen-insensitive material systems is an obvious engineering option, to date insensitive systems cannot meet the time-temperature-loading service extremes encountered. A short-term approach that is both feasible and technologically sound is the development and employment of hydrogen barrier coatings. The present project is concerned with developing, analyzing, and physically testing laminate composite hydrogen barrier systems, employing Inconel 718 as the structural material to be protected. Barrier systems will include all metallic, metallic-to-ceramic, and, eventually, metallic/ceramic composites as the lamellae. Since space propulsion implies repetitive engine firings without earth-based inspection and repair, coating durability will be closely examined, and testing regimes will include repetitive thermal cycling to simulate damage accumulation. The target accomplishments include: generation of actual hydrogen permeation data for metallic, ceramic-metallic, and hybrid metallic/ceramic composition barrier systems, practically none of which is currently extant; definition of physical damage modes imported to barrier systems due to thermal cycling, both transient temperature profiles and steady-state thermal mismatch stress states being examined as sources of damage; and computational models that incorporate general laminate schemes as described above, including manufacturing realities such as porosity, and whatever defects are introduced through service and characterized during the experimental programs.

  2. Performance of cork and ceramic matrix composite joints for re-entry thermal protection structures

    OpenAIRE

    Triantou, K; B. Perez; Marinou, A.; Florez, S; Mergia, K; Vekinis, G.; Barcena, J.; Rotärmel, W.; Zuber, C; de Montbrun, À.

    2016-01-01

    In view of spacecraft re-entry applications into planetary atmospheres, hybrid thermal protection systems based on cork and ceramic matrix composites are investigated. Joints of NORCOAT LIÈGE cork with C/Csingle bondSiC ceramic matrix composite were fabricated using a) high temperature commercial inorganic adhesives and b) in-situ polymerization of the cork on top of the CMC. Mechanical shear tests under ambient conditions and in liquid nitrogen are carried out. The ultimate shear strength of...

  3. Integral Textile Structure for 3-D CMC Turbine Airfoils

    Science.gov (United States)

    Marshall, David B. (Inventor); Cox, Brian N. (Inventor); Sudre, Olivier H. (Inventor)

    2017-01-01

    An integral textile structure for 3-D CMC turbine airfoils includes top and bottom walls made from an angle-interlock weave, each of the walls comprising warp and weft fiber tows. The top and bottom walls are merged on a first side parallel to the warp fiber tows into a single wall along a portion of their widths, with the weft fiber tows making up the single wall interlocked through the wall's thickness such that delamination of the wall is inhibited. The single wall suitably forms the trailing edge of an airfoil; the top and bottom walls are preferably joined along a second side opposite the first side and parallel to the radial fiber tows by a continuously curved section in which the weave structure remains continuous with the weave structure in the top and bottom walls, the continuously curved section being the leading edge of the airfoil.

  4. The Computer-Mediated Communication (CMC) Classroom: A Challenge of Medium, Presence, Interaction, Identity, and Relationship

    Science.gov (United States)

    Sherblom, John C.

    2010-01-01

    There is a "prevalence of computer-mediated communication (CMC) in education," and a concern for its negative psychosocial consequences and lack of effectiveness as an instructional tool. This essay identifies five variables in the CMC research literature and shows their moderating effect on the psychosocial, instructional expevrience of the CMC…

  5. Computer-Mediated Communication (CMC) in L2 Oral Proficiency Development: A Meta-Analysis

    Science.gov (United States)

    Lin, Huifen

    2015-01-01

    The ever growing interest in the development of foreign or second (L2) oral proficiency in a computer-mediated communication (CMC) classroom has resulted in a large body of studies looking at both the direct and indirect effects of CMC interventions on the acquisition of oral competences. The present study employed a quantitative meta-analytic…

  6. Improvement on filterability in the aerobic treatment of carboxymethyl cellulose (CMC wastewater

    Directory of Open Access Journals (Sweden)

    Qing Pei Ye

    2014-01-01

    Full Text Available CMC is chemically modified from natural cellulose and widely applied in various industries. CMC wastewater consists mainly of sodium glycolate, sodium chloride and water. With extremely high COD and salinity, high concentration CMC wastewater can’t be biologically treated, but with COD and salinity around 15000 mg/L and 30000 mg/L respectively, low concentration CMC wastewater can be aerobically treated. In a CMC factory, the treatment of low concentration wastewater with aerobic MBR was successful except for one serious problem: poor filterability. Two trial solutions: adding micronutrients and applying MBBR were expected to improve the filterability. In the experiment, adding micronutrients was achieved by mixing filtered natural water into the wastewater, rather than dosing chemicals into it. The treatment efficiency of both solutions was close, but adding micronutrients showed distinguished performance in improving filterability, which includes higher filtration flux and slighter membrane fouling. Adding micronutrients also effectively improved the filterability under severe salinity shock.

  7. DWPF waste glass Product Composition Control System

    Energy Technology Data Exchange (ETDEWEB)

    Brown, K.G.; Postles, R.L.

    1992-01-01

    The Defense Waste Processing Facility (DWPF) will be used to blend aqueous radwaste (PHA) with solid radwaste (Sludge) in a waste receipt vessel (the SRAT). The resulting SRAT material is transferred to the SME an there blended with ground glass (Frit) to produce a batch of melter feed slurry. The SME material is passed to a hold tank (the MFT) which is used to continuously feed the DWPF melter. The melter. The melter produces a molten glass wasteform which is poured into stainless steel canisters for cooling and, ultimately, shipment to and storage in a geologic repository. The Product Composition Control System (PCCS) is the system intended to ensure that the melt will be processible and that the glass wasteform will be acceptable. This document provides a description of this system.

  8. DWPF waste glass Product Composition Control System

    Energy Technology Data Exchange (ETDEWEB)

    Brown, K.G.; Postles, R.L.

    1992-07-01

    The Defense Waste Processing Facility (DWPF) will be used to blend aqueous radwaste (PHA) with solid radwaste (Sludge) in a waste receipt vessel (the SRAT). The resulting SRAT material is transferred to the SME an there blended with ground glass (Frit) to produce a batch of melter feed slurry. The SME material is passed to a hold tank (the MFT) which is used to continuously feed the DWPF melter. The melter. The melter produces a molten glass wasteform which is poured into stainless steel canisters for cooling and, ultimately, shipment to and storage in a geologic repository. The Product Composition Control System (PCCS) is the system intended to ensure that the melt will be processible and that the glass wasteform will be acceptable. This document provides a description of this system.

  9. Novel 3D C-SiC Composites for Hot Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Future NASA hypersonic vehicles offer a potential to incorporate advanced ceramic matrix composites (CMC). The key characteristics include excellent mechanical...

  10. Composite armor, armor system and vehicle including armor system

    Science.gov (United States)

    Chu, Henry S.; Jones, Warren F.; Lacy, Jeffrey M.; Thinnes, Gary L.

    2013-01-01

    Composite armor panels are disclosed. Each panel comprises a plurality of functional layers comprising at least an outermost layer, an intermediate layer and a base layer. An armor system incorporating armor panels is also disclosed. Armor panels are mounted on carriages movably secured to adjacent rails of a rail system. Each panel may be moved on its associated rail and into partially overlapping relationship with another panel on an adjacent rail for protection against incoming ordnance from various directions. The rail system may be configured as at least a part of a ring, and be disposed about a hatch on a vehicle. Vehicles including an armor system are also disclosed.

  11. Peer Evaluation in CMC Learning Environment and Writing Skill

    Directory of Open Access Journals (Sweden)

    Morteza Mellati

    2014-09-01

    Full Text Available Peer evaluation and technology-based instruction as the various domains of language teaching perspectives might affect language development. Group work in a technology-based environment might be more successful when learners are involved in developing the assessment process particularly peer assessment. This study investigated the effectiveness of peer evaluation in technology-based language environment and its effects on English writing ability. To reach this goal, 70 Iranian learners were participated in English language writing context. They were divided into two groups, one group assigned to CMC (Computer-Mediated Communication language learning context and the other assigned to a traditional learning environment. Both groups were encouraged to evaluate their classmates’ writing tasks. In addition, interviews were conducted with two learners. Comparing these two groups provides comprehensive guidelines for teachers as well as curriculum designers to set adjusted writing language environment for more effective and creative language teaching and learning. E-collaboration classroom tasks have high intrinsic motivation as well as significant effects on learners’ outcomes. Cooperative tasks specifically in technology-based environment lead learners to group working and consequently group learning. Computer-Mediated Communication is meaningful, especially in contexts in which teachers stimulate group work activities.

  12. Reliability and Confidence Interval Analysis of a CMC Turbine Stator Vane

    Science.gov (United States)

    Murthy, Pappu L. N.; Gyekenyesi, John P.; Mital, Subodh K.

    2008-01-01

    High temperature ceramic matrix composites (CMC) are being explored as viable candidate materials for hot section gas turbine components. These advanced composites can potentially lead to reduced weight, enable higher operating temperatures requiring less cooling and thus leading to increased engine efficiencies. However, these materials are brittle and show degradation with time at high operating temperatures due to creep as well as cyclic mechanical and thermal loads. In addition, these materials are heterogeneous in their make-up and various factors affect their properties in a specific design environment. Most of these advanced composites involve two- and three-dimensional fiber architectures and require a complex multi-step high temperature processing. Since there are uncertainties associated with each of these in addition to the variability in the constituent material properties, the observed behavior of composite materials exhibits scatter. Traditional material failure analyses employing a deterministic approach, where failure is assumed to occur when some allowable stress level or equivalent stress is exceeded, are not adequate for brittle material component design. Such phenomenological failure theories are reasonably successful when applied to ductile materials such as metals. Analysis of failure in structural components is governed by the observed scatter in strength, stiffness and loading conditions. In such situations, statistical design approaches must be used. Accounting for these phenomena requires a change in philosophy on the design engineer s part that leads to a reduced focus on the use of safety factors in favor of reliability analyses. The reliability approach demands that the design engineer must tolerate a finite risk of unacceptable performance. This risk of unacceptable performance is identified as a component's probability of failure (or alternatively, component reliability). The primary concern of the engineer is minimizing this risk in

  13. New method for evaluating composite reservoir systems

    Energy Technology Data Exchange (ETDEWEB)

    Benson, S.M.; Lai, C.H.

    1985-03-01

    A simple new technique has been developed for evaluating interference test data in radially symmetric composite reservoirs. The technique is based on the realization that systematic variations in the apparent storage coefficient (calculated from semi-log analysis of the late-time data are indicative of a two-mobility (k/..mu..) reservoir. By analyzing variations in the apparent storage coefficient, both the mobility and size of the inner region can be calculated. The technique is particularly useful for evaluating heterogeneous geothermal systems where the intersection of several faults, or hydrothermal alteration has created a high permeability region in the center of the geothermal field. The technique is applied to an extensive interference test in the geothermal reservoir at Klamath Falls, Oregon. 7 refs., 7 figs.

  14. Portuguese food composition database quality management system.

    Science.gov (United States)

    Oliveira, L M; Castanheira, I P; Dantas, M A; Porto, A A; Calhau, M A

    2010-11-01

    The harmonisation of food composition databases (FCDB) has been a recognised need among users, producers and stakeholders of food composition data (FCD). To reach harmonisation of FCDBs among the national compiler partners, the European Food Information Resource (EuroFIR) Network of Excellence set up a series of guidelines and quality requirements, together with recommendations to implement quality management systems (QMS) in FCDBs. The Portuguese National Institute of Health (INSA) is the national FCDB compiler in Portugal and is also a EuroFIR partner. INSA's QMS complies with ISO/IEC (International Organization for Standardisation/International Electrotechnical Commission) 17025 requirements. The purpose of this work is to report on the strategy used and progress made for extending INSA's QMS to the Portuguese FCDB in alignment with EuroFIR guidelines. A stepwise approach was used to extend INSA's QMS to the Portuguese FCDB. The approach included selection of reference standards and guides and the collection of relevant quality documents directly or indirectly related to the compilation process; selection of the adequate quality requirements; assessment of adequacy and level of requirement implementation in the current INSA's QMS; implementation of the selected requirements; and EuroFIR's preassessment 'pilot' auditing. The strategy used to design and implement the extension of INSA's QMS to the Portuguese FCDB is reported in this paper. The QMS elements have been established by consensus. ISO/IEC 17025 management requirements (except 4.5) and 5.2 technical requirements, as well as all EuroFIR requirements (including technical guidelines, FCD compilation flowchart and standard operating procedures), have been selected for implementation. The results indicate that the quality management requirements of ISO/IEC 17025 in place in INSA fit the needs for document control, audits, contract review, non-conformity work and corrective actions, and users' (customers

  15. Composite system reliability evaluation by stochastic calculation of system operation

    Energy Technology Data Exchange (ETDEWEB)

    Haubrick, H.-J.; Hinz, H.-J.; Landeck, E. [Dept. of Power Systems and Power Economics (Germany)

    1994-12-31

    This report describes a new developed probabilistic approach for steady-state composite system reliability evaluation and its exemplary application to a bulk power test system. The new computer program called PHOENIX takes into consideration transmission limitations, outages of lines and power stations and, as a central element, a highly sophisticated model to the dispatcher performing remedial actions after disturbances. The kernel of the new method is a procedure for optimal power flow calculation that has been specially adapted for the use in reliability evaluations under the above mentioned conditions. (author) 11 refs., 8 figs., 1 tab.

  16. Statistical applications for chemistry, manufacturing and controls (CMC) in the pharmaceutical industry

    CERN Document Server

    Burdick, Richard K; Pfahler, Lori B; Quiroz, Jorge; Sidor, Leslie; Vukovinsky, Kimberly; Zhang, Lanju

    2017-01-01

    This book examines statistical techniques that are critically important to Chemistry, Manufacturing, and Control (CMC) activities. Statistical methods are presented with a focus on applications unique to the CMC in the pharmaceutical industry. The target audience consists of statisticians and other scientists who are responsible for performing statistical analyses within a CMC environment. Basic statistical concepts are addressed in Chapter 2 followed by applications to specific topics related to development and manufacturing. The mathematical level assumes an elementary understanding of statistical methods. The ability to use Excel or statistical packages such as Minitab, JMP, SAS, or R will provide more value to the reader. The motivation for this book came from an American Association of Pharmaceutical Scientists (AAPS) short course on statistical methods applied to CMC applications presented by four of the authors. One of the course participants asked us for a good reference book, and the only book recomm...

  17. Calibration of 3D Woven Preform Design Code for CMC Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mechanical and thermal performance of CMC components benefit from low part count, integrally fabricated designs of 3D woven reinforcement. The advantages of these...

  18. Micromechanics Based Design/Analysis Codes for Advanced Composites

    Science.gov (United States)

    Mital, Subodh K.; Murthy, Pappu L. N.; Gyekenyesi, John P.

    2002-01-01

    Advanced high temperature Ceramic Matrix Composites (CMC) hold an enormous potential for use in aero and space related applications specifically for propulsion system components. Consequently, this has led to a multitude of research activities pertaining to fabrication, testing and modeling of these materials. The efforts directed at the development of ceramic matrix composites have focused primarily on improving the properties of the constituents as individual phases. It has, however, become increasingly clear that for CMC to be successfully employed in high temperature applications, research and development efforts should also focus on optimizing the synergistic performance of the constituent phases within the as-produced microstructure of the complex shaped CMC part. Despite their attractive features, the introduction of these materials in a wide spectrum of applications has been excruciatingly slow. The reasons are the high costs associated with the manufacturing and a complete experimental testing and characterization of these materials. Often designers/analysts do not have a consistent set of necessary properties and design allowables to be able to confidently design and analyze structural components made from these composites. Furthermore, the anisotropy of these materials accentuates the burden both on the test engineers and the designers by requiring a vastly increased amount of data/characterization compared to conventional materials.

  19. Effect of inorganic additives on solutions of nonionic surfactants III: CMC's and surface properties.

    Science.gov (United States)

    Schott, H; Han, S K

    1976-07-01

    Continuing work on the interaction of inorganic additives with nonionic surfactants in aqueous solution dealt with their effect on the CMC and surface tension. The surfactants were octoxynol and polyoxyethylated oleyl alcohol, containing an average of 9.5 and 10 ethylene oxide units, respectively. Their CMC values were lowered by most electrolytes studied, representing salting out of the surfactants. The steepest reductions in the CMC were produced by the nitrates of sodium and potassium, which had been found to lower the cloud points of nonionic surfactants, salting them out because of the inability of their cations to form complexes with the ether oxygen linkages of the polyoxyethylene moieties. However, even electrolytes with cations such as hydrogen, lithium, calcium, nickel, lead, and aluminum capable of forming complexes with the ether oxygens, thereby increasing the cloud points of the surfactants, lowered their CMC values. In the presence of increasing concentrations of the latter electrolytes, the CMC values frequently went through minima and approached the CMC of the surfactant in the absence of additives. Increases in the CMC over the entire range of additive concentrations investigated were produced by cadmium nitrate for octoxynol, urea for polyoxyethylated oleyl alcohol, and magnesium nitrate for both. Net increases in the plateau or micellar surface tension of polyoxyethylated oleyl alcohol, i.e., in the constant surface tension of surfactant solutions above the CMC, were brought about by the nitrates of cadmium, aluminum, and magnesium at low concentrations only and by urea at all concentrations. This increase is interpreted as salting in. The area per surfactant molecule adsorbed at the air-water interface was reduced by all added electrolytes. Urea caused no such reduction.

  20. Effect of carboxymethyl cellulose (CMC) as biopolymers to the edible film sorghum starch hydrophobicity characteristics

    Science.gov (United States)

    Putri, Rr. Dewi Artanti; Setiawan, Aji; Anggraini, Puji D.

    2017-03-01

    The use of synthetic plastic should be limited because it causes the plastic waste that can not be decomposed quickly, triggering environmental problems. The solution of the plastic usage is the use of biodegradable plastic as packaging which is environmentally friendly. Synthesis of edible film can be done with a variety of components. The component mixture of starch and cellulose derivative products are one of the methods for making edible film. Sorghum is a species of cereal crops containing starch amounted to 80.42%, where the use of sorghum in Indonesia merely fodder. Therefore, sorghum is a potential material to be used as a source of starch synthesis edible film. This research aims to study the characteristics of edible starch films Sorghum and assess the effect of CMC (Carboxymethyl Cellulose) as additional materials on the characteristics of biopolymers edible film produced sorghum starch. This study is started with the production of sorghum starch, then the film synthesizing with addition of CMC (5, 10, 15, 20, and 25% w/w starch), and finally the hydrophobicity characteristics test (water uptake test and water solubility test). The addition of CMC will decrease the percentage of water absorption to the film with lowest level of 65.8% in the degree of CMC in 25% (w/w starch). The addition of CMC also influences the water solubility of film, where in the degree of 25% CMC (w/w starch) the solubility of water was the lowest, which was 28.2% TSM.

  1. A compositional modelling framework for exploring MPSoC systems

    DEFF Research Database (Denmark)

    Tranberg-Hansen, Anders Sejer; Madsen, Jan

    2009-01-01

    This paper presents a novel compositional framework for system level performance estimation and exploration of Multi-Processor System On Chip (MPSoC) based systems. The main contributions are the definition of a compositional model which allows quantitative performance estimation to be carried out...

  2. Advanced resin systems for graphite epoxy composites

    Science.gov (United States)

    Gilwee, W. J.; Jayarajan, A.

    1980-01-01

    The value of resin/carbon fiber composites as lightweight structures for aircraft and other vehicle applications is dependent on many properties: environmental stability, strength, toughness, resistance to burning, smoke produced when burning, raw material costs, and complexity of processing. A number of woven carbon fiber and epoxy resin composites were made. The epoxy resin was commercially available tetraglycidylmethylene dianiline. In addition, composites were made using epoxy resin modified with amine and carboxyl terminated butadiene acrylonitrile copolymer. Strength and toughness in flexure as well as oxygen index flammability and NBS smoke chamber tests of the composites are reported.

  3. Synthesis and electrospinning carboxymethyl cellulose lithium (CMC-Li) modified 9,10-anthraquinone (AQ) high-rate lithium-ion battery.

    Science.gov (United States)

    Qiu, Lei; Shao, Ziqiang; Liu, Minglong; Wang, Jianquan; Li, Pengfa; Zhao, Ming

    2014-02-15

    New cellulose derivative CMC-Li was synthesized, and nanometer CMC-Li fiber was applied to lithium-ion battery and coated with AQ by electrospinning. Under the protection of inert gas, modified AQ/carbon nanofibers (CNF)/Li nanometer composite material was obtained by carbonization in 280 °C as lithium battery anode materials for the first time. The morphologies and structures performance of materials were characterized by using IR, (1)H NMR, SEM, CV and EIS, respectively. Specific capacity was increased from 197 to 226.4 mAhg(-1) after modification for the first discharge at the rate of 2C. Irreversible reduction reaction peaks of modified material appeared between 1.5 and 1.7 V and the lowest oxidation reduction peak of the difference were 0.42 V, the polarization was weaker. Performance of cell with CMC-Li with the high degree of substitution (DS) was superior to that with low DS. Cellulose materials were applied to lithium battery to improve battery performance by electrospinning. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Micromechanics-Based Computational Simulation of Ceramic Matrix Composites

    Science.gov (United States)

    Murthy, Pappu L. N.; Mutal, Subodh K.; Duff, Dennis L. (Technical Monitor)

    2003-01-01

    Advanced high-temperature Ceramic Matrix Composites (CMC) hold an enormous potential for use in aerospace propulsion system components and certain land-based applications. However, being relatively new materials, a reliable design properties database of sufficient fidelity does not yet exist. To characterize these materials solely by testing is cost and time prohibitive. Computational simulation then becomes very useful to limit the experimental effort and reduce the design cycle time, Authors have been involved for over a decade in developing micromechanics- based computational simulation techniques (computer codes) to simulate all aspects of CMC behavior including quantification of scatter that these materials exhibit. A brief summary/capability of these computer codes with typical examples along with their use in design/analysis of certain structural components is the subject matter of this presentation.

  5. Composite Matrix Systems for Cryogenic Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — As an alternative material to aluminum-lithium, cryotanks developed from fiber reinforced composites can offer significant weight savings in applications for fuel...

  6. Coordination and composition in multi-agent systems

    NARCIS (Netherlands)

    M. Dastani; F. Arbab (Farhad); F.S. de Boer (Frank)

    2005-01-01

    htmlabstractIn this paper we describe a channel-based exogenous coordination language, called Reo, and discuss its application to multi-agent systems. Reo supports a specific notion of compositionality for multi-agent systems that enables the composition and coordination of both individual agents as

  7. Topical report to Morgantown Energy Technology Center for the interfacial coatings for ceramic-matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-09

    This report summarizes the task conducted to examine various activities on interface development for ceramic-matrix composites (CMCs) intended for high-temperature applications. While several articles have been published on the subject of CMC interfaces, the purpose of this report is to describe the various ongoing efforts on interface concepts, material selection, and issues related to processing methods employed for developing interface coatings. The most exciting and new development in the field is the discovery of monazite as a potential interface material for mullite- and alumina-based composites. Monazite offers two critical properties to the CMC system; a weakly bonded layer due to its non-wetting behavior and chemical compatibility with both alumina and mullite up to very high temperatures (> 1,600 C). A description of the Department of Energy-related activities and some thoughts on processing issues, interface testing, and effects of processing on fiber strength are given.

  8. Preparation of CMC-modified melamine resin spherical nano-phase change energy storage materials.

    Science.gov (United States)

    Hu, Xiaofeng; Huang, Zhanhua; Zhang, Yanhua

    2014-01-30

    A novel carboxymethyl cellulose (CMC)-modified melamine-formaldehyde (MF) phase change capsule with excellent encapsulation was prepared by in situ polymerization. Effects of CMC on the properties of the capsules were studied by Fourier transformation infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electronic microscopy (SEM), X-ray diffractometry (XRD), and thermogravimetric analysis (TGA). The results showed that the CMC-modified capsules had an average diameter of about 50nm and good uniformity. The phase change enthalpy of the capsules was increased and the cracking ratio decreased by incorporating a suitable amount of CMC. The optimum phase change enthalpy of the nanocapsules was 83.46J/g, and their paraffin content was 63.1%. The heat resistance of the capsule shells decreased after CMC modification. In addition, the nanocapsule cracking ratio of the nanocapsules was 11.0%, which is highly attractive for their application as nano phase change materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. A CMC1-knockout reveals translation-independent control of human mitochondrial complex IV biogenesis.

    Science.gov (United States)

    Bourens, Myriam; Barrientos, Antoni

    2017-03-01

    Defects in mitochondrial respiratory chain complex IV (CIV) frequently cause encephalocardiomyopathies. Human CIV assembly involves 14 subunits of dual genetic origin and multiple nucleus-encoded ancillary factors. Biogenesis of the mitochondrion-encoded copper/heme-containing COX1 subunit initiates the CIV assembly process. Here, we show that the intermembrane space twin CX9C protein CMC1 forms an early CIV assembly intermediate with COX1 and two assembly factors, the cardiomyopathy proteins COA3 and COX14. A TALEN-mediated CMC1 knockout HEK293T cell line displayed normal COX1 synthesis but decreased CIV activity owing to the instability of newly synthetized COX1. We demonstrate that CMC1 stabilizes a COX1-COA3-COX14 complex before the incorporation of COX4 and COX5a subunits. Additionally, we show that CMC1 acts independently of CIV assembly factors relevant to COX1 metallation (COX10, COX11, and SURF1) or late stability (MITRAC7). Furthermore, whereas human COX14 and COA3 have been proposed to affect COX1 mRNA translation, our data indicate that CMC1 regulates turnover of newly synthesized COX1 prior to and during COX1 maturation, without affecting the rate of COX1 synthesis. © 2017 The Authors.

  10. High temperature metal matrix composites for future aerospace systems

    Science.gov (United States)

    Stephens, Joseph R.

    1988-01-01

    Research was conducted on metal matrix composites and intermetallic matrix composites to understand their behavior under anticipated future operating conditions envisioned for aerospace power and propulsion systems of the 21st century. Extremes in environmental conditions, high temperature, long operating lives, and cyclic conditions dictate that the test evaluations not only include laboratory testing, but simulated flight conditions. The various processing techniques employed to fabricate composites are discussed along with the basic research underway to understand the behavior of high temperature composites, and the relationship of this research to future aerospace systems.

  11. A novel composite membrane of chitosan-carboxymethyl cellulose polyelectrolyte complex membrane filled with nano-hydroxyapatite I. Preparation and properties.

    Science.gov (United States)

    Liuyun, Jiang; Yubao, Li; Chengdong, Xiong

    2009-08-01

    A novel tri-component composite membranes of chitosan/carboxymethyl cellulose (CS/CMC) polyelectrolyte complex membranes filled with different weight ratios of nano-hydroxyapatite (n-HA)(0, 20, 40 and 60 wt%), namely, n-HA/CS/CMC composite membrane, were prepared by self-assembly of static electricity. The structure and the properties of the composite membranes were investigated by Fourier transformed infrared spectroscopy(IR), X-ray diffraction(XRD), Scanning electron microscopy(SEM), mechanical performance measurement, swelling behavior test, and soaking behavior study in phosphate buffered saline (PBS) and simulate body fluid (SBF). The results showed that the n-HA/CS/CMC composite membrane was formed though superficial static electricity interaction among n-HA, CS and CMC. For the n-HA/CS/CMC composite membrane, the microstructure compatibility, mechanical property, swelling behavior, the degradation and bioactivity in vitro of the composite membrane were improved by the addition of n-HA, compared with CS/CMC polyelectrolyte complex membrane. Moreover, the n-HA/CS/CMC composite membrane with 40 wt% n-HA had the most highest mechanical property, which suggested that the novel n-HA/CS/CMC composite membrane with 40 wt% n-HA was more suitable to be used as guided bone tissue regeneration membrane than CS/CMC polyelectrolyte complex membrane.

  12. Advanced Environmental Barrier Coating Development for SiC-SiC Ceramic Matrix Composite Components

    Science.gov (United States)

    Zhu, Dongming; Harder, Bryan; Hurst, Janet B.; Halbig, Michael Charles; Puleo, Bernadette J.; Costa, Gustavo; Mccue, Terry R.

    2017-01-01

    This presentation reviews the NASA advanced environmental barrier coating (EBC) system development for SiC-SiC Ceramic Matrix Composite (CMC) combustors particularly under the NASA Environmentally Responsible Aviation, Fundamental Aeronautics and Transformative Aeronautics Concepts Programs. The emphases have been placed on the current design challenges of the 2700-3000F capable environmental barrier coatings for low NOX emission combustors for next generation turbine engines by using advanced plasma spray based processes, and the coating processing and integration with SiC-SiC CMCs and component systems. The developments also have included candidate coating composition system designs, degradation mechanisms, performance evaluation and down-selects; the processing optimizations using TriplexPro Air Plasma Spray Low Pressure Plasma Spray (LPPS), Plasma Spray Physical Vapor Deposition and demonstration of EBC-CMC systems. This presentation also highlights the EBC-CMC system temperature capability and durability improvements under the NASA development programs, as demonstrated in the simulated engine high heat flux, combustion environments, in conjunction with high heat flux, mechanical creep and fatigue loading testing conditions.

  13. Systems and methods for producing electrical discharges in compositions

    KAUST Repository

    Cha, Min Suk

    2015-09-03

    Systems and methods configured to produce electrical discharges in compositions, such as those, for example, configured to produce electrical discharges in compositions that comprise mixtures of materials, such as a mixture of a material having a high dielectric constant and a material having a low dielectric constant (e.g., a composition of a liquid having a high dielectric constant and a liquid having a low dielectric constant, a composition of a solid having a high dielectric constant and a liquid having a low dielectric constant, and similar compositions), and further systems and methods configured to produce materials, such as through material modification and/or material synthesis, in part, resulting from producing electrical discharges in compositions.

  14. Application of advanced composites in tokamak magnet systems

    Energy Technology Data Exchange (ETDEWEB)

    Long, C. J.

    1977-11-01

    The use of advanced (high-modulus) composites in superconducting magnets for tokamak fusion reactors is discussed. The most prominent potential application is as the structure in the pulsed poloidal-field coil system, where a significant reduction in eddy currents could be achieved. Present low-temperature data on the advanced composites are reviewed briefly; they are too meager to do more than suggest a broad class of composites for a particular application.

  15. Calorimetric Evidence about the Application of the Concept of CMC to Asphaltene Self-Association

    DEFF Research Database (Denmark)

    Garcia, Daniel Merino; Andersen, Simon Ivar

    2005-01-01

    usually found in the literature as the CMC region of asphaltenes indicates that this concept is not appropriate for asphaltene self-association. Tests were performed down to concentrations of 34ppm without any sign of a critical micellization or aggregation concentration. Based on the various techniques a......For many years, the concept of critical micellar concentration (CMC) has been projected from surfactant science into asphaltene science. There are several similarities between these two species, such as the stabilization of water-in-oil emulsions and surface activity, which suggested...... that asphaltenes may also have a concentration at which self-association occurs (CMC). This article presents evidence found by calorimetry and spectroscopic techniques, that suggest that this concept may not be adequate for asphaltene self-association in toluene solutions. Isothermal titration calorimetry has been...

  16. Biodegradation of PVP-CMC hydrogel film: a useful food packaging material.

    Science.gov (United States)

    Roy, Niladri; Saha, Nabanita; Kitano, Takeshi; Saha, Petr

    2012-06-20

    Hydrogels can offer new opportunities for the design of efficient packaging materials with desirable properties (i.e. durability, biodegradability and mechanical strength). It is a promising and emerging concept, as most of the biopolymer based hydrogels are supposed to be biodegradable, they can be considered as alternative eco-friendly packaging materials. This article reports about synthetic (polyvinylpyrrolidone (PVP)) and biopolymer (carboxymethyl cellulose (CMC)) based a novel hydrogel film and its nature of biodegradability under controlled environmental condition. The dry hydrogel films were prepared by solution casting method and designated as 'PVP-CMC hydrogel films'. The hydrogel film containing PVP and CMC in a ratio of 20:80 shows best mechanical properties among all the test samples (i.e. 10:90, 20:80, 50:50, 80:20 and 90:10). Thus, PVP-CMC hydrogel film of 20:80 was considered as a useful food packaging material and further experiments were carried out with this particular hydrogel film. Biodegradation of the PVP-CMC hydrogel films were studied in liquid state (Czapec-Dox liquid medium+soil extracts) until 8 weeks. Variation in mechanical, viscoelastic properties and weight loss of the hydrogel films with time provide the direct evidence of biodegradation of the hydrogels. About 38% weight loss was observed within 8 weeks. FTIR spectra of the hydrogel films (before and after biodegradation) show shifts of the peaks and also change in the peak intensities, which refer to the physico-chemical change in the hydrogel structure and SEM views of the hydrogels show how internal structure of the PVP-CMC film changes in the course of biodegradation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Compositionality issues in discrete, continuous and hybrid systems

    NARCIS (Netherlands)

    van der Schaft, Arjan; Schumacher, J.M.

    2000-01-01

    Models of complex dynamical systems are often built by connecting submodels of smaller parts. The key to this method is the operation of ``interconnection'' or ``composition'' which serves to define the whole in terms of its parts. In the setting of smooth differential equations the composition

  18. NPU-based image compositing in a distributed visualization system.

    Science.gov (United States)

    Pugmire, David; Monroe, Laura; Connor Davenport, Carolyn; DuBois, Andrew; DuBois, David; Poole, Stephen

    2007-01-01

    This paper describes the first use of a Network Processing Unit (NPU) to perform hardware-based image composition in a distributed rendering system. The image composition step is a notorious bottleneck in a clustered rendering system. Furthermore, image compositing algorithms do not necessarily scale as data size and number of nodes increase. Previous researchers have addressed the composition problem via software and/or custom-built hardware. We used the heterogeneous multicore computation architecture of the Intel IXP28XX NPU, a fully programmable commercial off-the-shelf (COTS) technology, to perform the image composition step. With this design, we have attained a nearly four-times performance increase over traditional software-based compositing methods, achieving sustained compositing rates of 22-28 fps on a 1,024 x 1,024 image. This system is fully scalable with a negligible penalty in frame rate, is entirely COTS, and is flexible with regard to operating system, rendering software, graphics cards, and node architecture. The NPU-based compositor has the additional advantage of being a modular compositing component that is eminently suitable for integration into existing distributed software visualization packages.

  19. Determination of an Active Mode in Composite Floor System ...

    African Journals Online (AJOL)

    In the majority of studies some significant notes were made but some such as active modes have been over looked. In this study some of them will be researched and classified to solve problems in limited areas of the study. Thus, to numerically recognise the active modes in a composite system, 24 coupled composite ...

  20. Sub-CMC solubilization of dodecane by rhamnolipid in saturated porous media

    Science.gov (United States)

    Yang, X.; Zhong, H.; Zhang, H.; Brusseau, M. L.

    2016-12-01

    Sub-CMC solubilization of dodecane by rhamnolipid in saturated porous mediaXin Yang1,Hua Zhong1, 2, 3 *, Hui Zhang1, Mark L Brusseau31 College of Environmental Science and Engineering, Hunan University, Changsha 410082, China;2 School of Water Resources and Hydropower Engineering, Wuhan University, Wuhan 430072, China;3 Department of Soil, Water and Environmental Science, University of Arizona, Tucson, Arizona 85721;*Corresponding author, E-mail: zhonghua@hnu.edu.cn, Tel: +86-731-88664182Purpose: Investigate solubilization of dodecane by monorhamnolipid at sub-CMC concentrations in porous media under dynamic flow conditions. Testify aggregate formation mechanism for the solubilization. Methods:One-dimension column experiment was implemented to test dodecane solubilization in glass beads by rhamnolipid at sub-CMC concentrations, and the effect of solubilization on the residual NAPL morphology was examined using X-ray tomography. A two-dimension flow cell was used to examine mobilization and solubilization of dodecane in quartz sand by sub-CMC rhamnolipid. The result of solubilization was compared to that of two synthetic surfactants, SDBS and Triton X-100, and a solvent, ethanol. Size, zeta potential and the morphology of particles in the effluent were also examined. Results: Results of the column and 2-D flow cell studies show enhancement of dodecane solubility by sub-CMC monorhamnolipid in the porous medium. Retention of rhamnolipid and detection of nano-size aggregates show that the solubilization is based on a sub-CMC aggregate-formation mechanism. The rhamnolipid is more efficient for the solubilization compared to the synthetic surfactants and ethanol, and significant solubilization could occur at a rhamnolipid concentration that did not cause mobilization. Conclusions:Results of the study demonstrate the aggregate-based solubilization of dodecane in porous media by rhamnolipid at sub-CMC concentrations. These results indicate a strategy of employing low

  1. It's Just a Game, Right? Types of Play in Foreign Language CMC

    OpenAIRE

    Chantelle N. Warner

    2004-01-01

    This study focuses on the various playful uses of language that occurred during a semester-long study of two German language courses using one type of synchronous network-based medium, the MOO. Research and use of synchronous computer-mediated communication (CMC) have flourished in the study of second-language acquisition (SLA) since the late 1990s; however, the primary focus has been on the potential benefits of using CMC to increase the amount of communication (Beauvois, 1997; Kern, 1995; W...

  2. Microwave assessment of two layer composite systems

    Energy Technology Data Exchange (ETDEWEB)

    Abdelazeez, M.K.; Ahmad, M.S.; Musameh, S.M.; Zihlif, A.M. (Univ. of Jordan, Amman (Jordan)); Martuscelli, E.; Ragosta, G.; Scafora, E. (Instituto di Ricerche su Technologia dei Polimero, Arco Felice (Italy))

    This paper reports results of further measurements performed on nickel coated carbon fiber-polypropylene composites at microwave frequencies. These measurements are performed on one and two specimens covering different fiber concentrations with different separating distances in the two specimens case. The measurements cover both of the insertion loss (IL) and the return loss (RL), and the results indicate strong dependence on the frequency and separating distance. The shielding effectiveness (SE) is determined from the measured values of IL and RL with its value exceeding 62 dB at 9 GHz and exceeding 55 dB at 10 GHz for the two specimens case. The two layers case seems to offer an interesting behavior over the frequency band as the separating distance start to exceed 10 mm. This specimen arrangement enhances the SE of this composite material compared with one layer case and offer a promising behavior for different applications.

  3. The system controlling the composition of clastic sediments

    Science.gov (United States)

    Johnsson, Mark J.

    1993-01-01

    The composition of clastic sediments and rocks is controlled by a complex suite of parameters operating during pedogenesis, erosion, transport, deposition, and burial. The principal first-order parameters include source rock composition, modification by chemical weathering, mechanical disaggregation and abrasion, authigenic inputs, hydrodynamic sorting, and diagenesis. Each of these first-order parameters is influenced to varying degrees by such factors as the tectonic settings of the source region, transportational system and depositional environment, climate, vegetation, relief, slope, and the nature and energy of transportational and depositional systems. These factors are not independent; rather a complicated web of interrelationships and feedback mechanisms causes many factors to be modulated by others. Accordingly, processes controlling the composition of clastic sediments are best viewed as constituting a system, and in evaluating compositional information the dynamics of the system must be considered as whole.

  4. ADHESIVE SYSTEM AFFECTS REPAIR BOND STRENGTH OF RESIN COMPOSITE

    OpenAIRE

    IRMAK, Özgür; Özge ÇELIKSÖZ; Begüm YILMAZ; Batu Can YAMAN

    2017-01-01

    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 stat...

  5. Effects of Synchronous and Asynchronous Computer-Mediated Communication (CMC) Oral Conversations on English Language Learners' Discourse Functions

    Science.gov (United States)

    AbuSeileek, Ali Farhan; Qatawneh, Khaleel

    2013-01-01

    This study aimed to explore the effects of synchronous and asynchronous computer mediated communication (CMC) oral discussions on question types and strategies used by English as a Foreign Language (EFL) learners. The participants were randomly assigned to two treatment conditions/groups; the first group used synchronous CMC, while the second…

  6. A Meta-Synthesis of Empirical Research on the Effectiveness of Computer-Mediated Communication (CMC) in SLA

    Science.gov (United States)

    Lin, Huifen

    2015-01-01

    This meta-analysis reports the results of a systematic synthesis of primary studies on the effectiveness of computer-mediated communication (CMC) in second language acquisition (SLA) for the period 2000-2012. By extracting information on 21 features from each primary study, this meta-analysis intends to summarize the CMC research literature for…

  7. Ni(0-CMC-Na Nickel Colloids in Sodium Carboxymethyl-Cellulose: Catalytic Evaluation in Hydrogenation Reactions

    Directory of Open Access Journals (Sweden)

    Abdallah Karim

    2011-01-01

    Full Text Available A recyclable catalyst, Ni(0-CMC-Na, composed of nickel colloids dispersed in a water soluble bioorganic polymer, sodium carboxymethylcellulose (CMC-Na, was synthesized by a simple procedure from readily available reagents. The catalyst thus obtained is stable and highly active in alkene hydrogenations.

  8. Preparation of crosslinked carboxymethylcellulose (CMC) by {sup 60} Co γ-ray irradiation and its biodegradable properties

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Youn Mook; Lee, Joon Ho; Nho, Young Chang [Radiation Research Center for Industry and Environment, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Son, Tae Il [Dept. of Biotechnology, College of Industrial Science, Graduate School, Chung Ang University, Seoul (Korea, Republic of)

    2007-05-15

    Biodegradable and biocompatible carboxymethylcellulose (CMC) hydrogels for personal care products such as infants diapers and feminine hygiene products were prepared by a γ- irradiation crosslinking technique. Hydrogels were prepared as a function of the CMC concentration, total dose, and degree of substitution (DS), and their physical properties such as the gel fraction, swelling ratio, pH-responsibility and biodegradability were investigated. The irradiation of an aqueous CMC solution led to a gelation in an aqueous solution of more than 10 w%, and the gel percent increased as the CMC concentration, total dose and DS increased. The equilibrium swelling behaviors of the hydrogels prepared in various conditions were examined in an aqueous solution, and the pH-response at a pH of 1.2 and 6.8 was investigated. CMC hydrogels showed a high gelation at a high CMC concentration with DS 1.2. Lastly, the effects of the crosslinking degree of the CMC on the hydrolysis reaction were examined by cellulase from Trichoderma reseei. It was found that the degradable reaction depended on the degree of the crosslinking of the CMC. Intermolecular crosslinking reactions were confirmed by the ESR spectra.

  9. Language Learning Going Global: Linking Teachers and Learners via Commercial Skype-Based CMC

    Science.gov (United States)

    Terhune, N. M.

    2016-01-01

    This paper reports on students' use of face-to-face synchronous computer-mediated communication (CMC) for oral language learning. It describes a university English language class designed to prepare students for overseas study in which a Skype-based English conversation school was piloted. The study offers analysis of how students used the CMC…

  10. My First CMC Article Revisited: A Window on Spanish L2 Interlanguage

    Science.gov (United States)

    Blake, Robert

    2016-01-01

    The computer-assisted language learning (CALL) field seems to change overnight with new technological affordances. Blake revisits his 2000 "LLT" article on computer-mediation communication (CMC) in order to reflect on how the field has examined this topic over the past decade or so. While the Interaction Hypothesis continues to guide…

  11. Persistence of oral coatings of CMC and starch-based custard desserts

    NARCIS (Netherlands)

    Wijk, R.A.de; Kapper, C.; Borsboom, P.; Prinz, J.F.

    2009-01-01

    Food coatings that remain after swallowing starch-based or CMC-based custard desserts were investigated for 19 subjects. Foods were orally processed for 5 s using a pre-defined protocol, after which the food was swallowed. The remaining food coating was assessed sensorially as well as instrumentally

  12. Determination of Consciousness and Awareness of the Public in Lefka about the Cyprus Mining Corporation (CMC)

    Science.gov (United States)

    Gündüz, Serife; Erbulut, Can; Öznacar, Behcet; Bastas, Mert

    2016-01-01

    Supporting the increase of environmental consciousness with environmental education is always important in order to make healthy recommendations specific to the countries. Aim of this study is to determine the awareness and consciousness of the local community against the environmental pollution caused by the CMC mine by survey technique. 123…

  13. CMC and Ethnic Communities: A Case Study of Chinese Students' Electronic Publications.

    Science.gov (United States)

    Zhang, Kewen; Hao, Xiaoming

    This paper presents a case study exploring the impact of Computer-Mediated Communication (CMC) on the formation of ethnic social groups, or communities, by examining the case of Chinese students in North America and other parts of the world. The paper (1) reviews the relationship between communication and community; (2) traces the development of…

  14. Aggression and Perceived National Face Threats in Mainland Chinese and Taiwanese CMC Discussion Boards

    Science.gov (United States)

    Kadar, Daniel Z.; Haugh, Michael; Chang, Wei-Lin Melody

    2013-01-01

    This study examines manifestations of verbal aggression in an intergroup context between Mainland Chinese and Taiwanese on computer-mediated communication (CMC) discussion boards. We examine the role of perceptions of national identity and face in occasioning instances of aggression in Sino-Taiwanese online interactions. It will be argued that…

  15. Computational mechanics in civil engineering (CMC). Fire - Heat transfer - Stress analysis

    NARCIS (Netherlands)

    Hendriks, M.A.N.; H¢iseth, K.V.; Hynne, T.; ¥verli, J.A.

    1999-01-01

    engineering, especially related to integrated analysis [1]. That is, analysis where two or more interacting effects or phenomena are analysed either staggered or simultaneously. CMC contains five main projects where frequently encountered problems in civil engineering will be treated by an

  16. Cooled Ceramic Composite Panel Tested Successfully in Rocket Combustion Facility

    Science.gov (United States)

    Jaskowiak, Martha H.

    2003-01-01

    Regeneratively cooled ceramic matrix composite (CMC) structures are being considered for use along the walls of the hot-flow paths of rocket-based or turbine-based combined-cycle propulsion systems. They offer the combined benefits of substantial weight savings, higher operating temperatures, and reduced coolant requirements in comparison to components designed with traditional metals. These cooled structures, which use the fuel as the coolant, require materials that can survive aggressive thermal, mechanical, acoustic, and aerodynamic loads while acting as heat exchangers, which can improve the efficiency of the engine. A team effort between the NASA Glenn Research Center, the NASA Marshall Space Flight Center, and various industrial partners has led to the design, development, and fabrication of several types of regeneratively cooled panels. The concepts for these panels range from ultra-lightweight designs that rely only on CMC tubes for coolant containment to more maintainable designs that incorporate metal coolant containment tubes to allow for the rapid assembly or disassembly of the heat exchanger. One of the cooled panels based on an all-CMC design was successfully tested in the rocket combustion facility at Glenn. Testing of the remaining four panels is underway.

  17. Environmental Barrier Coatings for Ceramic Matrix Composites - An Overview

    Science.gov (United States)

    Lee, Kang; van Roode, Mark; Kashyap, Tania; Zhu, Dongming; Wiesner, Valerie

    2017-01-01

    SiC/SiC Ceramic Matrix Composites (CMCs) are increasingly being considered as structural materials for advanced power generation equipment because of their light weight, higher temperature capability, and oxidation resistance. Limitations of SiC/SiC CMCs include surface recession and component cracking and associated chemical changes in the CMC. The solutions pursued to improve the life of SiC/SiC CMCs include the incorporation of coating systems that provide surface protection, which has become known as an Environmental Barrier Coating (EBC). The development of EBCs for the protection of gas turbine hot section CMC components was a continuation of coating development work for corrosion protection of silicon-based monolithics. Work on EBC development for SiC/SiC CMCs has been ongoing at several national laboratories and the original gas turbine equipment manufacturers. The work includes extensive laboratory, rig and engine testing, including testing of EBC coated SiC/SiC CMCs in actual field applications. Another EBC degradation issue which is especially critical for CMC components used in aircraft engines is the degradation from glassy deposits of calcium-magnesium-aluminosilicate (CMAS) with other minor oxides. This paper addresses the need for and properties of external coatings on SiC/SiC CMCs to extend their useful life in service and the retention of their properties.

  18. Shared Task System Description: Frustratingly Hard Compositionality Prediction

    DEFF Research Database (Denmark)

    Johannsen, Anders Trærup; Martinez Alonso, Hector; Rishøj, Christian

    2011-01-01

    We considered a wide range of features for the DiSCo 2011 shared task about compositionality prediction for word pairs, including COALS-based endocentricity scores, compositionality scores based on distributional clusters, statistics about wordnet-induced paraphrases, hyphenation, and the likelih......We considered a wide range of features for the DiSCo 2011 shared task about compositionality prediction for word pairs, including COALS-based endocentricity scores, compositionality scores based on distributional clusters, statistics about wordnet-induced paraphrases, hyphenation......, and the likelihood of long translation equivalents in other languages. Many of the features we considered correlated significantly with human compositionality scores, but in support vector regression experiments we obtained the best results using only COALS-based endocentricity scores. Our system was nevertheless...

  19. Design Concepts for Cooled Ceramic Matrix Composite Turbine Vanes Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The work proposed herein is to demonstrate that the higher temperature capabilities of Ceramic Matrix Composites (CMC) can be fully utilized to reduce emissions and...

  20. CMC blade with pressurized internal cavity for erosion control

    Science.gov (United States)

    Garcia-Crespo, Andres; Goike, Jerome Walter

    2016-02-02

    A ceramic matrix composite blade for use in a gas turbine engine having an airfoil with leading and trailing edges and pressure and suction side surfaces, a blade shank secured to the lower end of each airfoil, one or more interior fluid cavities within the airfoil having inlet flow passages at the lower end which are in fluid communication with the blade shank, one or more passageways in the blade shank corresponding to each one of the interior fluid cavities and a fluid pump (or compressor) that provides pressurized fluid (nominally cool, dry air) to each one of the interior fluid cavities in each airfoil. The fluid (e.g., air) is sufficient in pressure and volume to maintain a minimum fluid flow to each of the interior fluid cavities in the event of a breach due to foreign object damage.

  1. Compositions of Functions and Permutations Specified by Minimal Reaction Systems

    OpenAIRE

    Teh, Wen Chean

    2017-01-01

    This paper studies mathematical properties of reaction systems that was introduced by Enrenfeucht and Rozenberg as computational models inspired by biochemical reaction in the living cells. In particular, we continue the study on the generative power of functions specified by minimal reaction systems under composition initiated by Salomaa. Allowing degenerate reaction systems, functions specified by minimal reaction systems over a quarternary alphabet that are permutations generate the altern...

  2. Compositional verification of real-time systems using Ecdar

    DEFF Research Database (Denmark)

    David, A.; Larsen, K.G.; Møller, M.H.

    2012-01-01

    We present a specification theory for timed systems implemented in the Ecdar tool. We illustrate the operations of the specification theory on a running example, showing the models and verification checks. To demonstrate the power of the compositional verification, we perform an in depth case study...... of a leader election protocol; Modeling it in Ecdar as Timed input/output automata Specifications and performing both monolithic and compositional verification of two interesting properties on it. We compare the execution time of the compositional to the classical verification showing a huge difference...

  3. Optical Fiber Embedded in Epoxy Glass Unidirectional Fiber Composite System.

    Science.gov (United States)

    Severin, Irina; El Abdi, Rochdi; Corvec, Guillaume; Caramihai, Mihai

    2013-12-20

    We aimed to embed silica optical fibers in composites (epoxy vinyl ester matrix reinforced with E-glass unidirectional fibers in mass fraction of 60%) in order to further monitor the robustness of civil engineering structures (such as bridges). A simple system was implemented using two different silica optical fibers (F1-double coating of 172 µm diameter and F2-single coating of 101.8 µm diameter respectively). The optical fibers were dynamically tensile tested and Weibull plots were traced. Interfacial adhesion stress was determined using pull-out test and stress values were correlated to fracture mechanisms based on SEM observations. In the case of the optical fiber (OF) (F1)/resin system and OF (F1)/composite system, poor adhesion was reported that may be correlated to interface fracture at silica core level. Relevant applicable results were determined for OF (F2)/composite system.

  4. Use of the Materials Genome Initiative (MGI approach in the design of improved-performance fiber-reinforced SiC/SiC ceramic-matrix composites (CMCs

    Directory of Open Access Journals (Sweden)

    Jennifer S. Snipes

    2016-07-01

    Full Text Available New materials are traditionally developed using costly and time-consuming trial-and-error experimental efforts. This is followed by an even lengthier material-certification process. Consequently, it takes 10 to 20 years before a newly-discovered material is commercially employed. An alternative approach to the development of new materials is the so-called materials-by-design approach within which a material is treated as a complex hierarchical system, and its design and optimization is carried out by employing computer-aided engineering analyses, predictive tools and available material databases. In the present work, the materials-by-design approach is utilized to design a grade of fiber-reinforced (FR SiC/SiC ceramic matrix composites (CMCs, the type of materials which are currently being used in stationary components, and are considered for use in rotating components, of the hot sections of gas-turbine engines. Towards that end, a number of mathematical functions and numerical models are developed which relate CMC constituents’ (fibers, fiber coating and matrix microstructure and their properties to the properties and performance of the CMC as a whole. To validate the newly-developed materials-by-design approach, comparisons are made between experimentally measured and computationally predicted selected CMC mechanical properties. Then an optimization procedure is employed to determine the chemical makeup and processing routes for the CMC constituents so that the selected mechanical properties of the CMCs are increased to a preset target level.

  5. Structural Design of Dual-Mode Ramjets and Associated System Issues (Conception structurale des statoreacteurs mixtes et defis systeme associes)

    Science.gov (United States)

    2010-09-01

    presented to the lecturers, can be found in the references. RÉSUMÉ Le stage RTO-AVT-VKI “HIGH SPEED PROPULSION: ENGINE DESIGN – INTEGRATION AND...Propulsion a vitesse elevee : Conception du moteur - integration et gestion thermique ) 14. ABSTRACT The RTO-AVT-VKI course HIGH SPEED PROPULSION...Ramjets and Associated System Issues 14 - 2 RTO-EN-AVT-185 Acronyms CMC Ceramic matrix composite DCT Double Col Thermique DMR Dual-Mode

  6. Short- and long-term efficiency of carboxymethylcellulose (CMC) to prevent crystal formation in South African wine.

    Science.gov (United States)

    Greeff, A E; Robillard, B; du Toit, W J

    2012-01-01

    Crystal formation in bottled wine occurs due to the over-saturation of wine with potassium bitartrate (KHT) salt when exposed to low temperatures. In this study, special focus was given to the efficiency of a crystallisation-inhibiting additive, carboxymethylcellulose (CMC), which is widely used in the food industry. In 2008, CMC was authorised by the International Organisation of Vine and Wine (OIV) for use in white and sparkling wines, but is not yet officially permitted in all wine-producing countries. The use of CMC could be of economical importance to the wine industry because energy costs due to cooling can be reduced. Unlike traditional cooling methods, the use of CMC theoretically prevents the loss of acidity. In this study, the short- and long-term efficiencies of CMC were investigated in South African white, rosé and red wines. Efficiency was determined primarily by measuring changes in potassium (K(+)) and tartaric acid (H(2)T) concentrations and visual crystal formation. As part of this study CMC's efficiency was compared with several other crystal inhibition treatments, and was also evaluated for its temperature stability over a year. CMC's effect on colour and total phenols was also assessed. The results reveal a high efficiency in preventing losses in K(+) and H(2)T concentrations in white wines, even with an ageing period of up to 12 months. The addition of CMC to rosé wines also delivered certain positive results, but less so for red wine. Three different commercial CMCs were also compared with mannoproteins to prevent changes in K(+) and H(2)T concentrations in three different wines. Furthermore, sensory evaluation was performed to determine certain organoleptic changes as a result of CMC treatments.

  7. 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.

  8. Magnetic coupling mechanisms in particle/thin film composite systems

    Directory of Open Access Journals (Sweden)

    Giovanni A. Badini Confalonieri

    2010-12-01

    Full Text Available Magnetic γ-Fe2O3 nanoparticles with a mean diameter of 20 nm and size distribution of 7% were chemically synthesized and spin-coated on top of a Si-substrate. As a result, the particles self-assembled into a monolayer with hexagonal close-packed order. Subsequently, the nanoparticle array was coated with a Co layer of 20 nm thickness. The magnetic properties of this composite nanoparticle/thin film system were investigated by magnetometry and related to high-resolution transmission electron microscopy studies. Herein three systems were compared: i.e. a reference sample with only the particle monolayer, a composite system where the particle array was ion-milled prior to the deposition of a thin Co film on top, and a similar composite system but without ion-milling. The nanoparticle array showed a collective super-spin behavior due to dipolar interparticle coupling. In the composite system, we observed a decoupling into two nanoparticle subsystems. In the ion-milled system, the nanoparticle layer served as a magnetic flux guide as observed by magnetic force microscopy. Moreover, an exchange bias effect was found, which is likely to be due to oxygen exchange between the iron oxide and the Co layer, and thus forming of an antiferromagnetic CoO layer at the γ-Fe2O3/Co interface.

  9. Identifying Opportunities in the Development of Ceramic Matrix Composite (CMC) Materials for Armor Applications

    Science.gov (United States)

    2017-03-01

    These materials are currently used in aerospace, industrial, semiconductor , and automotive areas. 2.4 Patents Table 2 is a compilation of the...addition of CNTs (Zhang et al. 2009) and graphene oxide (Wang et al. 2016) into carbon fiber precursors. Finally, entire fibers have been synthesized...from nanostructures, such as graphene (Xin et al. 2015), which exhibits high-thermal conductivity but relatively low-mechanical properties when

  10. METHODOLOGICAL HURDLES IN CAPTURING CMC DATA: THE CASE OF THE MISSING SELF-REPAIR

    Directory of Open Access Journals (Sweden)

    Bryan Smith

    2008-02-01

    Full Text Available This paper reports on a study of the use of self-repair among learners of German in a task-based CMC environment. The purpose of the study was two-fold. The first goal sought to establish how potential interpretations of CMC data may be very different depending on the method of data collection and evaluation employed. The second goal was to explicitly examine the nature of CMC self-repair in the task-based foreign language CALL classroom. Paired participants (n=46 engaged in six jigsaw tasks over the course of one university semester via the chat function in Blackboard. Chat data were evaluated first by using only the chat log file and second by examining a video file of the screen capture of the entire interaction. Results show a fundamental difference in the interpretation of the chat interaction which varies as a function of the data collection and evaluation methods employed. The findings also suggest a possible difference in the nature of self-repair across face-to-face and SCMC environments. In view of the results, this paper calls for CALL researchers to abandon the reliance on printed chat log files when attempting to interpret SCMC interactional data.

  11. Viscoelastic behavior of mineralized (CaCO3) chitin based PVP-CMC hydrogel scaffolds

    Science.gov (United States)

    Čadež, Vida; Saha, Nabanita; Sikirić, Maja Dutour; Saha, Petr

    2017-05-01

    Enhancement of the mechanical as well as functional properties of the perspective mineralized PVP-CMC-CaCO3 hydrogel scaffold applicable for bone tissue engineering is quite essential. Therefore, the incorporation feasibility of chitin, a bioactive, antibacterial and biodegradable material, was examined in order to test its ability to enchance mechanical properties of the PVP-CMC-CaCO3 hydrogel scaffold. Chitin based PVP-CMC hydrogels were prepared and characterized both as non-mineralized and mineralized (CaCO3) form of hydrogel scaffolds. Both α-chitin (commercially bought) and β-chitin (isolated from the cuttlebone) were individually tested. It was observed that at 1% strain all hydrogel scaffolds have linear trend, with highly pronounced elastic properties in comparison to viscous ones. The complex viscosity has directly proportional behavior with negative slope against angular frequency within the range of ω = 0.1 - 100 rad.s-1. Incorporation of β-chitin increased storage modulus of all mineralized samples, making it interesting for further research.

  12. NUG reliability implications in a composite generation and transmission system

    Energy Technology Data Exchange (ETDEWEB)

    Billinton, R.; Adzanu, S. [Saskatchewan Univ., Saskatoon, SK (Canada)

    1995-12-31

    The cost implications of non-utility generation (NUG) on composite generation and transmission system reliability was discussed and customer interruption costs in two test systems was reviewed. Reliability analysis based on generation, transmission and distribution with hierarchical levels (HL) was described. The Roy Billinton test system (RBTS) and the IEEE-Reliability test system were used for testing in conjunction with COMREL (COMposite system RELiability evaluation) software developed at the University of Saskatchewan. A description of COMREL, and best case results were presented for the RBTS. Assessment of energy costs for unserved energy accounted for the composite customer damage function (CCDF), interrupted energy assessment rate (IEAR), and expected energy not supplied (EENS) index. The utilization of reliability worth concepts was summarized, and was used to indicate different impacts on both load point and overall power system customer costs of unserved energy. It was concluded that quantitative reliability assessments can be performed in systems with NUGs, and that they can be extended to include reliability worth evaluations. 17 refs., 15 figs.

  13. Effect of finishing system on carcass characteristics and composition ...

    African Journals Online (AJOL)

    A study was conducted to evaluate the influence of feeding systems on carcass characteristics and composition of Mubende goats and their Boer goat crossbreds. A 2 x 3 factorial arrangement was used to randomly allocate 60 castrates, 30 purebred Mubende and 30 Mubende x Boer, aged 9 - 12 months, to three feeding ...

  14. Concentrate composition for automatic milking systems - effect on milking frequency

    DEFF Research Database (Denmark)

    Madsen, Jørgen; Weisbjerg, Martin Riis; Hvelplund, Torben

    2010-01-01

    The purpose of this study was to investigate the potential of affecting milking frequency in an Automatic Milking System (AMS) by changing ingredient composition of the concentrate fed in the AMS. In six experiments, six experimental concentrates were tested against a Standard concentrate all...

  15. Leakage Testing for Different Adhesive Systems and Composites to ...

    African Journals Online (AJOL)

    shrinkage is one of the most important causes of failures. Departments of Pedodontics ... Kılınç G. Leakage testing for different adhesive systems and composites to permanent teeth. Niger J Clin Pract 2017;20:787-91. Date of Acceptance: 16-Nov-2015 .... practiced to the cavity, by brushing the adhesive over the entire ...

  16. The S-matrix for scattering of composite systems

    NARCIS (Netherlands)

    Nieuwenhuizen, P. van; Ruijgrok, Th.

    1967-01-01

    It is shown that the asymptotically stationary states, as introduced by Van Hove1), provide a natural tool to describe the scattering of composite systems. The scattering problem is formulated in terms of these a.s. states and a unitary S-matrix is defined. In this paper we treat the formal aspects

  17. Geomorphological investigation of multiphase glacitectonic composite ridge systems in Svalbard

    Science.gov (United States)

    Lovell, Harold; Benn, Douglas I.; Lukas, Sven; Spagnolo, Matteo; Cook, Simon J.; Swift, Darrel A.; Clark, Chris D.; Yde, Jacob C.; Watts, Tom

    2018-01-01

    Some surge-type glaciers on the High-Arctic archipelago of Svalbard have large glacitectonic composite ridge systems at their terrestrial margins. These have formed by rapid glacier advance into proglacial sediments during the active surge phase, creating multicrested moraine complexes. Such complexes can be formed during single surge advances or multiple surges to successively less-extensive positions. The few existing studies of composite ridge systems have largely relied on detailed information on internal structure and sedimentology to reconstruct their formation and links to surge processes. However, natural exposures of internal structure are commonly unavailable, and the creation of artificial exposures is often problematic in fragile Arctic environments. To compensate for these issues, we investigate the potential for reconstructing composite ridge system formation based on geomorphological evidence alone, focusing on clear morphostratigraphic relationships between ridges within the moraine complex and relict meltwater channels/outwash fans. Based on mapping at the margins of Finsterwalderbreen (in Van Keulenfjorden) and Grønfjordbreen (in Grønfjorden), we show that relict meltwater channels that breach outer parts of the composite ridge systems are in most cases truncated upstream within the ridge complex by an inner pushed ridge or ridges at their ice-proximal extents. Our interpretation of this relationship is that the entire composite ridge system is unlikely to have formed during the same glacier advance but is instead the product of multiple advances to successively less-extensive positions, whereby younger ridges are emplaced on the ice-proximal side of older ridges. This indicates that the Finsterwalderbreen composite ridge system has been formed by multiple separate advances, consistent with the cyclicity of surges. Being able to identify the frequency and magnitude of former surges is important as it provides insight into the past behaviour of

  18. Blending effects on adsorption and micellization of different membrane protein solubilizers II. A thermodynamic study on a mixed system of CHAPS with a bile salt in pH 7.4 phosphate buffer solution.

    Science.gov (United States)

    Oh, Se-Woung; Na, Jin-Su; Ko, Jeong-Soo; Nagadome, Shigemi; Sugihara, Gohsuke

    2008-03-15

    For a mixed system of a typical membrane protein solubilizer CHAPS (a derivative of a bile acid cholic acid) combined with a bile salt (sodium salt of glycocholic acid, NaGC), which is also a candidate as a membrane protein solubilizer, micellization and adsorbed film formation in a phosphate buffer solution of pH 7.4 at 303 K were studied paying special attention to the synergistic effect upon mixing. The collection of sufficient data based on plots of surface tension (gamma) versus logarithmic concentration (C(t) or m(t)) in total molality at discrete mole fractions (X(2)) in the mixture of surfactants 1 and 2 (where 1 and 2 correspond to CHAPS and NaGC, respectively) allowed us to accurately determine critical micelle concentration (CMC), minimum surface tension at CMC (gamma(CMC)), and the slope (dgamma/dlnC(t)) from the gamma-lnC(t) curves in the concentration range just below CMC. These data enabled us to estimate surface excess (Gamma(t)), and mean molecular area (A(m)) in addition to such parameters as the minimum surface Gibbs energy (G(min)((S))), pC(20) and CMC/C(20) related to synergism accompanied by blending. Applying the regular solution theory (RST), the relation of compositions of the singly dispersed phase (X(2)) and the micellar phase (Y(2)) as well as the interaction parameter (omega(R)) (by using the Rubingh's equations) were estimated. The relation between the composition in the adsorbed film (Z(2)) and X(2) together with the interaction parameter (omega(A)) in the adsorbed film was also estimated. The partial molecular area (PMA), gamma(CMC), and G(min)((S)) were examined as functions of X(2) and/or Z(2.) The resultant CMC-X(2) and CMC-Y(2) curves and omega(R) and omega(A) values have demonstrated that mixed micelles and adsorbed film formation are attained accompanying to some extent enhanced intermolecular interaction (with negative omega(R) and omega(A) values). Comparing with previous results for mixed systems of CHAPS with n

  19. Composite power system adequacy assessment based on postoptimal analysis

    OpenAIRE

    SAFDARIAN, Amir; FIRUZABAD, Mahmud FOTUHI; AMINIFAR, Farrokh

    2014-01-01

    The modeling and evaluation of enormous numbers of contingencies are the most challenging impediments associated with composite power system adequacy assessment, particularly for large-scale power systems. Optimal power flow (OPF) solution, as a widely common approach, is normally employed to model and analyze each individual contingency as an independent problem. However, mathematical representations associated with diverse states are slightly different in one or a few generating un...

  20. Cmc1p Is a Conserved Mitochondrial Twin CX9C Protein Involved in Cytochrome c Oxidase Biogenesis▿ †

    OpenAIRE

    Horn, Darryl; Al-Ali, Hassan; Barrientos, Antoni

    2008-01-01

    Copper is an essential cofactor of two mitochondrial enzymes: cytochrome c oxidase (COX) and Cu-Zn superoxide dismutase (Sod1p). Copper incorporation into these enzymes is facilitated by metallochaperone proteins which probably use copper from a mitochondrial matrix-localized pool. Here we describe a novel conserved mitochondrial metallochaperone-like protein, Cmc1p, whose function affects both COX and Sod1p. In Saccharomyces cerevisiae, Cmc1p localizes to the mitochondrial inner membrane fac...

  1. Subscale Testing of a Ceramic Composite Cooled Panel Led to Its Design and Fabrication for Scramjet Engine Testing

    Science.gov (United States)

    Jaskowiak, Martha H.

    2004-01-01

    In a partnership between the NASA Glenn Research Center and Pratt & Whitney, a ceramic heat exchanger panel intended for use along the hot-flow-path walls of future reusable launch vehicles was designed, fabricated, and tested. These regeneratively cooled ceramic matrix composite (CMC) panels offer lighter weight, higher operating temperatures, and reduced coolant requirements in comparison to their more traditional metallic counterparts. A maintainable approach to the design was adopted which allowed the panel components to be assembled with high-temperature fasteners rather than by permanent bonding methods. With this approach, the CMC hot face sheet, the coolant containment system, and backside structure were all fabricated separately and could be replaced individually as the need occurred during use. This maintainable design leads to both ease of fabrication and reduced cost.

  2. Comparing cone beam laminographic system trajectories for composite NDT

    Directory of Open Access Journals (Sweden)

    Neil O'Brien

    2016-11-01

    Full Text Available We compare the quality of reconstruction obtainable using various laminographic system trajectories that have been described in the literature, with reference to detecting defects in composite materials in engineering. We start by describing a laminar phantom representing a simplified model of composite panel, which models certain defects that may arise in such materials, such as voids, resin rich areas, and delamination, and additionally features both blind and through holes along multiple axes. We simulate ideal cone-beam projections of this phantom with the different laminographic trajectories, applying both Simultaneous Iterative Reconstruction Technique (SIRT and Conjugate Gradient Least Squares (CGLS reconstruction algorithms. We compare the quality of the reconstructions with a view towards optimising the scan parameters for defect detectability in composite NDT applications.

  3. Does hyaluronic acid-carboxymethylcellulose (HA-CMC) membrane interfere with the healing of intestinal suture lines and abdominal incisions?

    Science.gov (United States)

    Yamaner, Sümer; Kalayci, Murat; Barbaros, Umut; Balik, Emre; Bulut, Türker

    2005-03-01

    Although hyaluronic acid-carboxymethylcellulose (HA-CMC) membrane has the advantage of preventing intraabdominal adhesions, it has theoretical risk of negative effects on the healing of intestinal suture lines by forming a barrier between the suture lines and neighboring serosal surfaces. This study evaluated the effect of HA-CMC on bowel anastomoses, scar healing, and intraabdominal adhesion formation. Two groups of 10 male Sprague-Dawley rats were examined. In the first group, laparotomy was performed with a median incision. Colotomy on the cecum and a single-layer repair of the bowel wall was performed. HA-CMC membrane was placed on the cecal suture line and under the laparotomy incision before abdominal closure. The second group had the same procedure but no HA-CMC membrane was placed. The animals were killed on postoperative day 14. Intraabdominal adhesions, laparotomy suture line endurance, bursting pressure of the repaired cecal wall, and tissue hydroxyproline levels were determined. The repaired cecal wall was also examined histopathologically. The statistical analyses revealed that HA-CMC prevented intraabdominal adhesions significantly. No negative effects of this material on the healing of the bowel and laparotomy suture lines were observed. HA-CMC appears to be a safe material to prevent intraabdominal adhesions, without negative effects on the healing of abdominal incisions and bowel suture lines.

  4. Improvement of Fish Sauce Quality by Strain CMC5-3-1: A Novel Species of Staphylococcus sp.

    Science.gov (United States)

    Udomsil, Natteewan; Rodtong, Sureelak; Tanasupawat, Somboon; Yongsawatdigul, Jirawat

    2015-09-01

    Staphylococcus sp. CMC5-3-1 and CMS5-7-5 isolated from fermented fish sauce at 3 to 7 mo, respectively, showed different characteristics on protein hydrolysis and volatile formation. These Gram-positive cocci were able to grow in up to 15% NaCl with the optimum at 0.5% to 5% NaCl in tryptic soy broth. Based on ribosomal 16S rRNA gene sequences, Staphylococcus sp. CMC5-3-1 and CMS5-7-5 showed 99.0% similarity to that of Staphylococcus piscifermentans JCM 6057(T) , but DNA-DNA relatedness was Staphylococcus sp. CMC5-3-1 was 740.5 mM, which was higher than that inoculated by the strain CMS5-7-5 (662.14 mM, P Staphylococcus sp. CMC5-3-1 showed the highest content of total glutamic acid (P Staphylococcus sp. CMC5-3-1 was 2-methypropanal, contributing to the desirable dark chocolate note. Staphylococcus sp. CMC5-3-1 could be applied as a starter culture to improve the umami and aroma of fish sauce. © 2015 Institute of Food Technologists®

  5. Refractory metal alloys and composites for space nuclear power systems

    Science.gov (United States)

    Titran, Robert H.; Stephens, Joseph R.; Petrasek, Donald W.

    1988-01-01

    Space power requirements for future NASA and other U.S. missions will range from a few kilowatts to megawatts of electricity. Maximum efficiency is a key goal of any power system in order to minimize weight and size so that the Space Shuttle may be used a minimum number of times to put the power supply into orbit. Nuclear power has been identified as the primary power source to meet these high levels of electrical demand. One method to achieve maximum efficiency is to operate the power supply, energy conservation system, and related components at relatively high temperatures. For systems now in the planning stages, design temperatures range from 1300 K for the immediate future to as high as 1700 K for the advanced systems. NASA Lewis Research Center has undertaken a research program on advanced technology of refractory metal alloys and composites that will provide baseline information for space power systems in the 1900's and the 21st century. Special emphasis is focused on the refractory metal alloys of niobium and on the refractory metal composites which utilize tungsten alloy wires for reinforcement. Basic research on the creep and creep-rupture properties of wires, matrices, and composites are discussed.

  6. Ceramic Matrix Composite Turbine Disk for Rocket Engines

    Science.gov (United States)

    Effinger, Mike; Genge, Gary; Kiser, Doug

    2000-01-01

    NASA has recently completed testing of a ceramic matrix composite (CMC), integrally bladed disk (blisk) for rocket engine turbopumps. The turbopump's main function is to bring propellants from the tank to the combustion chamber at optimal pressures, temperatures, and flow rates. Advantages realized by using CMC blisks are increases in safety by increasing temperature margins and decreasing costs by increasing turbopump performance. A multidisciplinary team, involving materials, design, structural analysis, nondestructive inspection government, academia, and industry experts, was formed to accomplish the 4.5 year effort. This article will review some of the background and accomplishments of the CMC Blisk Program relative to the benefits of this technology.

  7. Blending effects on adsorption and micellization of different membrane protein solubilizers: a thermodynamic study on three mixed systems of CHAPS with MEGA-8, -9 and -10 in pH 7.2 phosphate buffer solution.

    Science.gov (United States)

    Ko, Jeong-Soo; Oh, Se-Woung; Kim, Kyung-Woo; Nakashima, Noriko; Nagadome, Shigemi; Sugihara, Gohsuke

    2005-10-10

    By means of surface tension measurement (Wilhelmy method), micellization and adsorbed film formation were investigated for three combinations of mixed surfactant systems, all of which are used for solubilizing membrane proteins: a typical zwitterionic surfactant, CHAPS (a derivative of cholic acid) with n-alkyl (octyl, nonyl and decyl)-N-glucamides, MEGA-n (n=8, 9, 10). The data based on plotting of surface tension (gamma) versus logarithmic total molarity (or molality) (Ct or Mt) as a function of mole fraction of surfactant 2 (2 corresponds to MEGA-n's) enabled us to determine critical micellization concentration (CMC), minimum surface tension at CMC (gammaCMC), surface excess (Gamma(t)), mean molecular surface area (Am), the minimum Gibbs energy (Gmin(S)) of adsorbed film of both single and mixed surfactant systems and partial molecular area (PMA) in addition to parameters such as pC20 and CMC/C20 being related to synergism accompanied by blending (mixing) in regard to surface activity as well as micelle forming ability. On the basis of the regular solution theory, the relations of compositions of singly dispersed phase (X2), micellar phase (Y2) and adsorbed film (Z2) were estimated, and then the interaction parameters in micelles (omegaR) and in the adsorbed film phase (omegaA) were also calculated. From both the CMC-X2 and CMC-Y2 curves, it was found for all the combinations to show synergistically enhanced ability of mixed micelle formation as well as surface tension reduction. The resultant synergism coming from blending CHAPS with MEGA-n's was discussed in comparison with different combinations of various types of surfactants including membrane proteins solubilizers.

  8. Time evolution of pore system in lime - Pozzolana composites

    Science.gov (United States)

    Doleželová, Magdaléna; Čáchová, Monika; Scheinherrová, Lenka; Keppert, Martin

    2017-11-01

    The lime - pozzolana mortars and plasters are used in restoration works on building cultural heritage but these materials are also following the trend of energy - efficient solutions in civil engineering. Porosity and pore size distribution is one of crucial parameters influencing engineering properties of porous materials. The pore size distribution of lime based system is changing in time due to chemical processes occurring in the material. The present paper describes time evolution of pore system in lime - pozzolana composites; the obtained results are useful in prediction of performance of lime - pozzolana systems in building structures.

  9. Novel CMC material based on a Si{sub 3}N{sub 4} matrix

    Energy Technology Data Exchange (ETDEWEB)

    Rak, Z.S. [Netherlands Energy Research Foundation (ECN), Petten (Netherlands)

    2000-08-01

    Ceramic-matrix composites (CMCs) are potential candidates for low-temperature applications by substituting for conventional ferrous materials and light alloys in brake discs in transportation systems, for pump sealing in chemical engineering, etc. Here a new C/Si{sub 3}N{sub 4} composite manufactured by an inexpensive method, consisting of a ceramic slurry infiltration followed by a liquid polymer infiltration and pyrolysis step, is described. (orig.)

  10. Quantum key distribution for composite dimensional finite systems

    Science.gov (United States)

    Shalaby, Mohamed; Kamal, Yasser

    2017-06-01

    The application of quantum mechanics contributes to the field of cryptography with very important advantage as it offers a mechanism for detecting the eavesdropper. The pioneering work of quantum key distribution uses mutually unbiased bases (MUBs) to prepare and measure qubits (or qudits). Weak mutually unbiased bases (WMUBs) have weaker properties than MUBs properties, however, unlike MUBs, a complete set of WMUBs can be constructed for systems with composite dimensions. In this paper, we study the use of weak mutually unbiased bases (WMUBs) in quantum key distribution for composite dimensional finite systems. We prove that the security analysis of using a complete set of WMUBs to prepare and measure the quantum states in the generalized BB84 protocol, gives better results than using the maximum number of MUBs that can be constructed, when they are analyzed against the intercept and resend attack.

  11. An Integrated Global Atmospheric Composition Observing System: Progress and Impediments

    Science.gov (United States)

    Keating, T. J.

    2016-12-01

    In 2003-2005, a vision of an integrated global observing system for atmospheric composition and air quality emerged through several international forums (IGACO, 2004; GEO, 2005). In the decade since, the potential benefits of such a system for improving our understanding and mitigation of health and climate impacts of air pollution have become clearer and the needs more urgent. Some progress has been made towards the goal: technology has developed, capabilities have been demonstrated, and lessons have been learned. In Europe, the Copernicus Atmospheric Monitoring Service has blazed a trail for other regions to follow. Powerful new components of the emerging global system (e.g. a constellation of geostationary instruments) are expected to come on-line in the near term. But there are important gaps in the emerging system that are likely to keep us from achieving for some time the full benefits that were envisioned more than a decade ago. This presentation will explore the components and benefits of an integrated global observing system for atmospheric composition and air quality, some of the gaps and obstacles that exist in our current capabilities and institutions, and efforts that may be needed to achieve the envisioned system.

  12. Compositional Verification of Multi-Station Interlocking Systems

    DEFF Research Database (Denmark)

    Macedo, Hugo Daniel dos Santos; Fantechi, Alessandro; Haxthausen, Anne Elisabeth

    2016-01-01

    Because interlocking systems are highly safety-critical complex systems, their automated safety verification is an active research topic investigated by several groups, employing verification techniques to produce important cost and time savings in their certification. However, such systems also...... pose a big challenge to current verification methodologies, due to the explosion of state space size as soon as large, if not medium sized, multi-station systems have to be controlled. For these reasons, verification techniques that exploit locality principles related to the topological layout...... method to verify the size of rather large networks, we propose a compositional approach that is particularly suitable to address multi-station interlocking systems which control a whole line composed of stations linked by mainline tracks. Indeed, it turns out that for such networks, and for the adopted...

  13. Composite system reliability evaluation using sequential Monte Carlo simulation

    Science.gov (United States)

    Jonnavithula, Annapoorani

    Monte Carlo simulation methods can be effectively used to assess the adequacy of composite power system networks. The sequential simulation approach is the most fundamental technique available and can be used to provide a wide range of indices. It can also be used to provide estimates which can serve as benchmarks against which other approximate techniques can be compared. The focus of this research work is on the reliability evaluation of composite generation and transmission systems with special reference to frequency and duration related indices and estimated power interruption costs at each load bus. One of the main objectives is to use the sequential simulation method to create a comprehensive technique for composite system adequacy evaluation. This thesis recognizes the need for an accurate representation of the load model at the load buses which depends on the mix of customer sectors at each bus. Chronological hourly load curves are developed in this thesis, recognizing the individual load profiles of the customers at each load bus. Reliability worth considerations are playing an ever increasing role in power system planning and operation. Different methods for bus outage cost evaluation are proposed in this thesis. It may not be computationally feasible to use the sequential simulation method with time varying loads at each bus in large electric power system networks. Time varying load data may also not be available at each bus. This research work uses the sequential methodology as a fundamental technique to calibrate other non sequential methods such as the state sampling and state transition sampling techniques. Variance reduction techniques that improve the efficiency of the sequential simulation procedure are investigated as a part of this research work. Pertinent features that influence reliability worth assessment are also incorporated. All the proposed methods in this thesis are illustrated by application to two reliability test systems. In addition

  14. The use of sodium hyaluronate-carboxymethylcellulose (HA-CMC) barrier in gynecologic malignancies: a retrospective review of outcomes.

    Science.gov (United States)

    Tan, Annie; Argenta, Peter; Ramirez, Rose; Bliss, Robin; Geller, Melissa

    2009-02-01

    Concerns exist regarding the safety of sodium hyaluronate-carboxymethylcellulose (HA-CMC, Seprafilm) adhesion barrier in regard to cancer survival as a result of in vitro data demonstrating that hyaluronan, a component of HA-CMC, may promote tumor growth. We sought to determine whether use of HA-CMC is associated with duration of disease-free or overall survival and rates of immediate complication in patients with gynecologic malignancies. We identified 202 consecutive patients with epithelial ovarian, fallopian tube, and primary peritoneal cancer who underwent initial surgical staging or interval debulking at the University of Minnesota between January 2001 and December 2004. Information on patients' demographics, medical history, surgical procedures, postoperative complications, disease stage, histology, adjuvant therapy, and disease-free and overall survival was collected from medical records. Survival curves were compared between patients receiving or not receiving HA-CMC by stratified Cox regression models, log rank, and Wilcoxon tests. The level of significance was set to alpha = .05 for each test. Eighty patients received intraoperative placement of HA-CMC and 122 did not. Immediate postoperative complication rates were equivalent in both groups. Median follow-up was 2.1 years. There was no difference in disease-free survival (5-year estimate 23.6% vs. 33.3%, P = .80) or overall survival (5-year estimate 29.7% vs. 40.3%, P = .75) between those who received HA-CMC and those who did not. Our retrospective analysis suggests that HA-CMC adhesion barrier does not affect disease-free survival or overall survival; nor does it increase the immediate postoperative complication rates in patients undergoing abdominal surgery for ovarian, fallopian tube, and primary peritoneal carcinomas.

  15. Non-CMC Solutions of the Einstein Constraint Equations on Compact Manifolds with Apparent Horizon Boundaries

    Science.gov (United States)

    Holst, Michael; Meier, Caleb; Tsogtgerel, G.

    2017-11-01

    In this article we continue our effort to do a systematic development of the solution theory for conformal formulations of the Einstein constraint equations on compact manifolds with boundary. By building in a natural way on our recent work in Holst and Tsogtgerel (Class Quantum Gravity 30:205011, 2013), and Holst et al. (Phys Rev Lett 100(16):161101, 2008, Commun Math Phys 288(2):547-613, 2009), and also on the work of Maxwell (J Hyperbolic Differ Eqs 2(2):521-546, 2005a, Commun Math Phys 253(3):561-583, 2005b, Math Res Lett 16(4):627-645, 2009) and Dain (Class Quantum Gravity 21(2):555-573, 2004), under reasonable assumptions on the data we prove existence of both near- and far-from-constant mean curvature (CMC) solutions for a class of Robin boundary conditions commonly used in the literature for modeling black holes, with a third existence result for CMC appearing as a special case. Dain and Maxwell addressed initial data engineering for space-times that evolve to contain black holes, determining solutions to the conformal formulation on an asymptotically Euclidean manifold in the CMC setting, with interior boundary conditions representing excised interior black hole regions. Holst and Tsogtgerel compiled the interior boundary results covered by Dain and Maxwell, and then developed general interior conditions to model the apparent horizon boundary conditions of Dainand Maxwell for compact manifolds with boundary, and subsequently proved existence of solutions to the Lichnerowicz equation on compact manifolds with such boundary conditions. This paper picks up where Holst and Tsogtgerel left off, addressing the general non-CMC case for compact manifolds with boundary. As in our previous articles, our focus here is again on low regularity data and on the interaction between different types of boundary conditions. While our work here serves primarily to extend the solution theory for the compact with boundary case, we also develop several technical tools that have

  16. Síntesis de carboximetilcelulosa (CMC) a partir de pastas de plantas anuales

    OpenAIRE

    Barba Pacheco, Claudia

    2002-01-01

    Palabras clave: materiales lignocelulósicos residuales, chopo, pino, paja de trigo, plantas anuales, abacá, sisal, yute, lino, Miscanthus sinensis, bagazo de caña de azúcar, henequén, pastas de cocción rápida sosa/AQ, pastas IRSP, carboximetilcelulosa, comportamiento reológico, grado de sustitución.El presente trabajo describe la preparación y caracterización de muestras de carboximetilcelulosa (CMC) a partir de diferentes materiales lignocelulósicos tanto residuales como no madereros, así c...

  17. [Consideration about chemistry, manufacture and control (CMC) key problems in simplified registration of classical traditional Chinese medicine excellent prescriptions].

    Science.gov (United States)

    Wang, Zhi-Min; Liu, Ju-Yan; Liu, Xiao-Qian; Wang, De-Qin; Yan, Li-Hua; Zhu, Jin-Jin; Gao, Hui-Min; Li, Chun; Wang, Jin-Yu; Li, Chu-Yuan; Ni, Qing-Chun; Huang, Ji-Sheng; Lin, Juan

    2017-05-01

    As an outstanding representative of traditional Chinese medicine(TCM) prescriptions accumulated from famous TCM doctors' clinical experiences in past dynasties, classical TCM excellent prescriptions (cTCMeP) are the most valuable part of TCM system. To support the research and development of cTCMeP, a series of regulations and measures were issued to encourage its simplified registration. There is still a long-way to go because many key problems and puzzles about technology, registration and administration in cTCMeP R&D process are not resolved. Based on the analysis of registration and management regulations of botanical drug products in FDA of USA and Japan, and EMA of Europe, the possible key problems and countermeasures in chemistry, manufacture and control (CMC) of simplified registration of cTCMeP were analyzed on the consideration of its actual situation. The method of "reference decoction extract by traditional prescription" (RDETP) was firstly proposed as standard to evaluate the quality and preparation uniformity between the new developing product under simplified registration and traditional original usages of cTCMeP, instead of Standard Decoction method in Japan. "Totality of the evidence" approach, mass balance and bioassay/biological assay of cTCMeP were emphatically suggested to introduce to the quality uniformity evaluation system in the raw drug material, drug substance and final product between the modern product and traditional decoction. Copyright© by the Chinese Pharmaceutical Association.

  18. Thermal Protection System Application to Composite Cryotank Technology Demonstrator

    Science.gov (United States)

    Protz, Alison; Nettles, Mindy

    2015-01-01

    The EM41 Thermal Protection System (TPS) team contributed to the success of the Composite Cryotank Technology Demonstrator (CCTD) manufacturing by developing and implementing a low-cost solution to apply cryoinsulation foam on the exterior surface of the tank in the NASA Marshall Space Flight Center (MSFC) TPS Development Facility, Bldg. 4765. The TPS team used techniques developed for the smallscale composite cryotank to apply Stepanfoam S-180 polyurethane foam to the 5.5-meter CCTD using a manual spray process. Manual spray foam technicians utilized lifts and scaffolding to access the barrel and dome sections of the large-scale tank in the horizontal orientation. During manufacturing, the tank was then oriented vertically, allowing access to the final barrel section for manual spray foam application. The CCTD was the largest application of manual spray foam performed to date with the S-180 polyurethane foam and required the TPS team to employ best practices for process controls on the development article.

  19. CMC Participation in the Regional Centre for Strategic Studies (RCSS) Workshop: Defense, Technology and Cooperative Security in South Asia

    Energy Technology Data Exchange (ETDEWEB)

    Biringer, K.L.; Olsen, J.

    1998-11-01

    As an ongoing part of the collaborative efforts between the Cooperative Monitoring Center (CMC) at Sandia National Laboratories, the United States Arms Control and Disarmament Agency (ACDA), and U.S. Department of Energy (DOE), staff from the CMC served as faculty in conducting a workshop in Shanghai, China. Sponsor of the workshop was the Regional Centre for Strategic Studies (RCSS) based in Colombo, Sri Lanka. The workshop included participants from throughout South Asia and China. The CMC presented four sessions related to the role of monitoring technologies in promoting regional security and building confidence among nations. Participation in these workshops supports U.S. efforts to further regional cooperation and promote arms control, nonproliferation and other cooperative securily measures and supplements efforts funded by DOE and ACDA over the past four years. The RCSS Shanghai meeting permitted a continued CMC involvement in regionally conducted training for anew generation of leaders in government, the military, and academia throughout South Asia and China. Nuclear issues are clearly a dominant South Asian concern since the nuclear tests of May 1998. However, there remains a strong interest in identifying opportunities for increased trade and reduced tensions in other areas. The RCSS and other regional organizations are enthusiastic about continued CMC involvement in future regional courses.

  20. Antimicrobial and release study of drug loaded PVA/PEO/CMC wound dressings.

    Science.gov (United States)

    Gupta, Bhuvanesh; Agarwal, Roopali; Sarwar Alam, M

    2014-06-01

    The aim of the present study was to develop PVA/PEO/CMC/aloe vera (PPCAV) and PVA/PEO/CMC/curcumin (PPCCu) dressings with nonwoven polyester fabric as the support layer via freeze-drying (FD) approach. Tetracycline hydrochloride drug (TC) was loaded along with curcumin and aloe vera on these dressings. The morphology of the dressings was characterized by scanning electron microscopy. The swelling behavior, water vapor transmission rate (WVTR), in vitro drug release and antimicrobial nature were analyzed to assess the applicability of these freeze-dried membranes as wound dressing materials. The results show that these dressings made from PPCAVTC and PPCCuTC were highly porous with three-dimensional interconnected porous morphology. The cumulative release of drug from the dressings increases with increasing immersion time and continued up to 24 h, after that it gets leveled off. These dressings evidenced wonderful antimicrobial nature in vitro. These dressings were found to have more than 900 % PBS uptake, WVTR was found to be in the range 2,000-2,500 gm(-2) day(-1). These dressings possess many characteristics desirable in an ideal wound dressing material.

  1. It's Just a Game, Right? Types of Play in Foreign Language CMC

    Directory of Open Access Journals (Sweden)

    Chantelle N. Warner

    2004-05-01

    Full Text Available This study focuses on the various playful uses of language that occurred during a semester-long study of two German language courses using one type of synchronous network-based medium, the MOO. Research and use of synchronous computer-mediated communication (CMC have flourished in the study of second-language acquisition (SLA since the late 1990s; however, the primary focus has been on the potential benefits of using CMC to increase the amount of communication (Beauvois, 1997; Kern, 1995; Warschauer, 1997, motivate students (Beauvois, 1997; Kern, 1995; Warschauer, 1997 and foster the exchange of ideas (Beauvois, 1997; Kern, 1995; von der Emde, Schneider, & Kötter, 2001; Warschauer, 1997. Only more recently has research within SLA begun to investigate the types of communication that occur online.1 An analysis of the transcripts from a second-semester German course and an upper-level German communication course reveal that a large portion of the language use online cannot be described using standard referential definitions of communication, but rather is playful in nature. Using research from SLA and theories on social interaction, this article investigates the different types of play that occurred within the online discussions and the possible implications of the presence of play in online discourse.

  2. PERFORMANCE EVALUATION OF CEILING RADIANT COOLING SYSTEM IN COMPOSITE CLIMATE

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Anuj [Malaviya National Institute of Technology (MNIT), Jaipur, India; Mathur, Jyotirmay [Malaviya National Institute of Technology (MNIT), Jaipur, India; Bhandari, Mahabir S [ORNL

    2015-01-01

    Radiant cooling systems are proving to be an energy efficient solution due to higher thermal capacity of cooling fluid especially for the buildings that require individual zone controls and where the latent loads are moderate. The Conventional air conditioners work at very low temperature i.e.5-8 c (refrigerant evaporator inlet) while the radiant cooling systems, also referred as high temperature cooling system, work at high temperatures i.e. 14-18 c. The radiant cooling systems can maintain lower MRT (Mean Radiant Temperature) as ceiling panels maintain uniform temperature gradient inside room and provide higher human comfort. The radiant cooling systems are relatively new systems and their operation and energy savings potential are not quantified for a large number of buildings and operational parameters. Moreover, there are only limited numbers of whole building simulation studies have been carried out for these systems to have a full confidence in the capability of modelling tools to simulate these systems and predict the impact of various operating parameters. Theoretically, savings achieve due to higher temperature set point of chilled water, which reduces chiller-running time. However, conventional air conditioner runs continuously to maintain requisite temperature. In this paper, experimental study for performance evaluation of radiant cooling system carried out on system installed at Malaviya National Institute of Technology Jaipur. This paper quantifies the energy savings opportunities and effective temperature by radiant cooling system at different chilled water flow rates and temperature range. The data collected/ analysed through experimental study will used for calibration and validation of system model of building prepared in building performance simulation software. This validated model used for exploring optimized combinations of key parameters for composite climate. These optimized combinations will used in formulation of radiant cooling system

  3. The equilibrium compositions of methanol synthesis system by cornstalk syngas

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, L.F.; Du, L.; Zhao, Q.L.; Li, X.B.; Ming, H.T.; Wu, B. [North China Inst. of Water Conservancy and Hydroelectric Power, Zhengzhou (China). Dept. of Environmental Engineering

    2008-07-01

    Methanol is produced by decomposed biomass from agricultural residues. Various thermo-chemical gasification methods are used to process the cornstalks in order to produce syngas. The syngas is then purified using de-oxygenation, de-sulfurization, and catalytic cracking processes. This paper described a series of catalytic methanol synthesis experiments conducted in a tubular-flow integral and isothermal reactor. The aim of the study was to determine the density and reaction heat of preparing methanol with syngas. The experiments were conducted to examine reaction temperatures; pressure; catalyst types; catalyst particle size; syngas flow; and the composition of syngas. Equilibrium constants, compositions, and concentrations of the equilibrium system for methanol synthesis were calculated using SHBWR state equations under given reaction pressures. The study showed that under pressure, K{sub p1} is a function of temperature, pressure, and composition, while K{sub f1} is a function of temperature. Data obtained in the study will be used to design commercial synthesis equipment. 10 refs., 1 tab., 1 fig.

  4. CO oxidation on Alsbnd Au nano-composite systems

    Science.gov (United States)

    Rajesh, C.; Majumder, C.

    2018-03-01

    Using first principles method we report the CO oxidation behaviour of Alsbnd Au nano-composites in three different size ranges: Al6Au8, Al13Au42 and a periodic slab of Alsbnd Au(1 1 1) surface. The clusters prefer enclosed structures with alternating arrangement of Al and Au atoms, maximising Auδ-sbnd Alδ+ bonds. Charge distribution analysis suggests the charge transfer from Al to Au atoms, corroborated by the red shift in the density of states spectrum. Further, CO oxidation on these nano-composite systems was investigated through both Eley - Rideal and Langmuir Hinshelwood mechanism. While, these clusters interact with O2 non-dissociatively with an elongation of the Osbnd O bond, further interaction with CO led to formation of CO2 spontaneously. On contrary, the CO2 evolution by co-adsorption of O2 and CO molecules has a transition state barrier. On the basis of the results it is inferred that nano-composite material of Alsbnd Au shows significant promise toward effective oxidative catalysis.

  5. Artificial immune system for effective properties optimization of magnetoelectric composites

    Science.gov (United States)

    Poteralski, Arkadiusz; Dziatkiewicz, Grzegorz

    2018-01-01

    The optimization problem of the effective properties for magnetoelectric composites is considered. The effective properties are determined by the semi-analytical Mori-Tanaka approach. The generalized Eshelby tensor components are calculated numerically by using the Gauss quadrature method for the integral representation of the inclusion problem. The linear magnetoelectric constitutive equation is used. The effect of orientation of the electromagnetic materials components is taken into account. The optimization problem of the design is formulated and the artificial immune system is applied to solve it.

  6. Graphene/Na carboxymethyl cellulose composite for Li-ion batteries prepared by enhanced liquid exfoliation

    Energy Technology Data Exchange (ETDEWEB)

    Naboka, Olga, E-mail: olga.naboka@nrc-cnrc.gc.ca [Energy, Mining and Environment Portfolio, National Research Council Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6 (Canada); Automotive and Surface Transportation Portfolio, National Research Council Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6 (Canada); Yim, Chae-Ho, E-mail: chae-ho.yim@nrc-cnrc.gc.ca [Energy, Mining and Environment Portfolio, National Research Council Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6 (Canada); Automotive and Surface Transportation Portfolio, National Research Council Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6 (Canada); Abu-Lebdeh, Yaser, E-mail: yaser.abu-lebdeh@nrc-cnrc.gc.ca [Energy, Mining and Environment Portfolio, National Research Council Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6 (Canada); Automotive and Surface Transportation Portfolio, National Research Council Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6 (Canada)

    2016-11-15

    Highlights: • Concentrated graphene dispersions were prepared using microwave enhanced exfoliation. • Microwave heating increased graphene concentration at least by 34%. • Graphene concentration in its dispersions reached 4.29 mg/ml. • Graphene/NaCMC composite with 38.65 wt% graphene content was prepared. • Graphene/NaCMC composite increased Si capacity by 30%. - Abstract: In the present work, we report a sonication-assisted exfoliation method of graphene preparation enhanced by the use of microwave heating and “green” exfoliant – sodium carboxymethyl cellulose (NaCMC). Introducing microwave heating during sonication of graphite dispersions in aqueous solutions of NaCMC results in the formation of graphene dispersions with concentration as high as 4.29 mg/ml. It is found that drying the dispersions results in the formation of graphene/NaCMC composites with graphene content up to 38.65 wt%. A study of the composite with High Resolution Transmission Electron Microscopy and Raman Spectroscopy reveals the formation of few-layer graphene approximately below five layers. The as-prepared graphene/NaCMC composite shows higher capacities than commercial graphite in Li-ion half cells reaching 397 mAh/g{sub (graphene)}. Also, when the composite is used with a nanosilicon (33 wt%) in a Li-ion half cell high initial reversible capacities of 1611 mAh/g{sub (Si)} with good cyclability and rate capability have been reached.

  7. Psychological underpinnings of intrafamilial computer-mediated communication: a preliminary exploration of CMC uptake with parents and siblings.

    Science.gov (United States)

    Goby, Valerie Priscilla

    2011-06-01

    This preliminary study investigates the uptake of computer-mediated communication (CMC) with parents and siblings, an area on which no research appears to have been conducted. Given the lack of relevant literature, grounded theory methodology was used and online focus group discussions were conducted in an attempt to generate suitable hypotheses for further empirical studies. Codification of the discussion data revealed various categories of meaning, namely: a perceived inappropriateness of CMC with members of family of origin; issues relating to the family generational gap; the nature of the offline sibling/parent relationship; the non-viability of online affordances such as planned self-disclosure, deception, identity construction; and disinhibition in interactions with family-of-origin members. These themes could be molded into hypotheses to assess the psychosocial limitations of CMC and to determine if it can indeed become a ubiquitous alternative to traditional communication modes as some scholars have claimed.

  8. Infra-red and vibration tests of hybrid ablative/ceramic matrix technological breadboards for earth re-entry thermal protection systems

    OpenAIRE

    Barcena, Jorge; Garmendia, Iñaki; Triantou, Kostoula; Mergia, Konstatina; Perez, Beatriz; Florez, Sonia; Pinaud, Gregory; Bouilly, Jean-Marc; Fischer, Wolfgang P.P.

    2017-01-01

    A new thermal protection system for atmospheric earth re-entry is proposed. This concept combines the advantages of both reusable and ablative materials to establish a new hybrid concept with advanced capabilities. The solution consists of the design and the integration of a dual shield resulting on the overlapping of an external thin ablative layer with a Ceramic Matrix Composite (CMC) thermo-structural core. This low density ablative material covers the relatively small heat peak encountere...

  9. Mathematical analysis of composite systems of liquid crystal and polymer

    Science.gov (United States)

    Shen, Quan

    This thesis deals with mathematical modeling of the composite material consisting of liquid crystal and polymer. Such systems are important in the applications. The mathematical work consists in minimizing the total free energy of a system in a geometrically complex domain. The total energy consists of the bulk Oseen-Frank free energy of the liquid crystal plus the surface contribution. The latter arises as a result of the contact interaction between the liquid crystal and the polymeric component. The first part of the work presents a two-dimensional prototype model. The effective equations for the composite configurations are obtained by means of homogenization limits, and subsequently analyzed and computed by numerical methods. One of the main mathematical difficulties of such analyses is the presence of defects in the model. This becomes an important issue in the study of physically realistic three-dimensional configurations. In order to overcome such a difficulty, the original model is replaced by a relaxed one: while the unit vector constraint is omitted, a penalty term is included in the energy. The idea is borrowed from the Ginzburg-Landau modeling of superconductivity and the unit director condition will be satisfied approximately while allowing for defects (i.e., points or lines where the length of director is zero). The effective equations are studied, and the relaxation of the length of the directors is eventually removed through the limit of the penalty term. The external magnetic field is added and the effect on the composite system is discussed. The last part of the thesis deals with systems of liquid crystal droplets in a polymeric isotropic matrix. The droplet configurations are of bipolar type, i.e., spherical-type shapes with two defects as opposite poles. The dipole line provides a new tool to construct anisotropic systems. A mathematical model for bipolar droplet is constructed and analyzed for both fixed and free boundary problems. The thesis

  10. Shear bond strength of self-etching bonding systems in combination with various composites used for repairing aged composites.

    Science.gov (United States)

    Teixeira, Erica C; Bayne, Stephen C; Thompson, Jeffrey Y; Ritter, Andre V; Swift, Edward J

    2005-01-01

    Repair of worn, broken or discolored composite restorations can be accomplished using new composite material and dentin bonding systems. The purpose of this study was to investigate the effectiveness of self-etching adhesive systems for composite re-bonding procedures onto different composite substrates that had been aged for 6 years prior to testing. Two hundred cylinders (4 mm x 5 mm) of composite were fabricated using 4 hybrid composites [AeliteFil (Bisco), Prodigy (SDS Kerr), TPH (Dentsply Caulk), and Z100 (3M ESPE)] following manufacturers' directions and stored for 6 years in 1% NaCl solution. After aging, each specimen was wet polished through 600-grit SiC and randomly assigned to a self-etching bonding system (Adper Prompt L-Pop/Z100 [3M ESPE]; Tyrian One-Step Plus/AeliteFil [Bisco]; OptiBond Solo Plus SE/Prodigy [SDS Kerr], Xeno III/TPH [Dentsply Caulk]) or a total-etch control (Prime&Bond NT/TPH [Dentsply Caulk]) (n = 10 per group). Shear bond strengths (SBS) for repairs were evaluated after 48 h (crosshead speed = 0.5 mm/min) and were compared by two-way ANOVA (p = 0.05) with Tukey post-hoc tests. Significant differences (p bonding systems), but the interaction was not significant. SBS for bonding systems were from highest to lowest: (1) Prime&Bond NT, (2) OptiBond Solo Plus SE, (3) Adper Prompt L-Pop, (4) Xeno III, (5) Tyrian One-Step Plus. SBS of the repair systems to Z100 were significantly lower than those to the other composite substrates. Self-etching systems can be used to repair aged composite, but the efficacy of repair of aged composite is system dependent.

  11. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2014-01-01

    Cue Rondo is an open composition to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound/video files will in some cases only provide a few minutes' sample, or the visuals will not appear at all...

  12. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2011-01-01

    Strategies are open compositions to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them in full...

  13. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2010-01-01

    New Year is an open composition to be realised by improvising musicians. It is included in "From the Danish Seasons" (see under this title). See more about my composition practise in the entry "Composition - General Introduction". This work is licensed under a Creative Commons "by-nc" License. You...

  14. Composition

    DEFF Research Database (Denmark)

    2014-01-01

    Memory Pieces are open compositions to be realised solo by an improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them...

  15. Incorporating Cyber Layer Failures in Composite Power System Reliability Evaluations

    Directory of Open Access Journals (Sweden)

    Yuqi Han

    2015-08-01

    Full Text Available This paper proposes a novel approach to analyze the impacts of cyber layer failures (i.e., protection failures and monitoring failures on the reliability evaluation of composite power systems. The reliability and availability of the cyber layer and its protection and monitoring functions with various topologies are derived based on a reliability block diagram method. The availability of the physical layer components are modified via a multi-state Markov chain model, in which the component protection and monitoring strategies, as well as the cyber layer topology, are simultaneously considered. Reliability indices of composite power systems are calculated through non-sequential Monte-Carlo simulation. Case studies demonstrate that operational reliability downgrades in cyber layer function failure situations. Moreover, protection function failures have more significant impact on the downgraded reliability than monitoring function failures do, and the reliability indices are especially sensitive to the change of the cyber layer function availability in the range from 0.95 to 1.

  16. Compositional Verification of Interlocking Systems for Large Stations

    DEFF Research Database (Denmark)

    Fantechi, Alessandro; Haxthausen, Anne Elisabeth; Macedo, Hugo Daniel dos Santos

    2017-01-01

    -network: in this way granting the access to a route is essentially a decision local to the sub-network, and the interfaces with the rest of the network easily abstract away less interesting details related to the external world. Following up on previous work, where we defined a compositional verification method......Railway interlocking systems are responsible to grant exclusive access to a route, that is a sequence of track elements, through a station or a network. Formal verification that basic safety rules regarding exclusive access to routes are satisfied by an implementation is still a challenge...... that started considering routes that overlap between sub-networks in interlocking systems governing a multi-station line, we attack the verification of large networks, which are typically those in main stations of major cities, and where routes are very intertwined and can hardly be separated into sub...

  17. Defense strategies for asymmetric networked systems under composite utilities

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Nageswara S. [ORNL; Ma, Chris Y. T. [Hang Seng Management College, Hon Kong; Hausken, Kjell [University of Stavanger, Norway; He, Fei [Texas A& M University, Kingsville, TX, USA; Yau, David K. Y. [Singapore University of Technology and Design; Zhuang, Jun [University at Buffalo (SUNY)

    2017-11-01

    We consider an infrastructure of networked systems with discrete components that can be reinforced at certain costs to guard against attacks. The communications network plays a critical, asymmetric role of providing the vital connectivity between the systems. We characterize the correlations within this infrastructure at two levels using (a) aggregate failure correlation function that specifies the infrastructure failure probability giventhe failure of an individual system or network, and (b) first order differential conditions on system survival probabilities that characterize component-level correlations. We formulate an infrastructure survival game between an attacker and a provider, who attacks and reinforces individual components, respectively. They use the composite utility functions composed of a survival probability term and a cost term, and the previously studiedsum-form and product-form utility functions are their special cases. At Nash Equilibrium, we derive expressions for individual system survival probabilities and the expected total number of operational components. We apply and discuss these estimates for a simplified model of distributed cloud computing infrastructure

  18. COMPOSITE METHOD OF RELIABILITY RESEARCH FOR HIERARCHICAL MULTILAYER ROUTING SYSTEMS

    Directory of Open Access Journals (Sweden)

    R. B. Tregubov

    2016-09-01

    Full Text Available The paper deals with the idea of a research method for hierarchical multilayer routing systems. The method represents a composition of methods of graph theories, reliability, probabilities, etc. These methods are applied to the solution of different private analysis and optimization tasks and are systemically connected and coordinated with each other through uniform set-theoretic representation of the object of research. The hierarchical multilayer routing systems are considered as infrastructure facilities (gas and oil pipelines, automobile and railway networks, systems of power supply and communication with distribution of material resources, energy or information with the use of hierarchically nested functions of routing. For descriptive reasons theoretical constructions are considered on the example of task solution of probability determination for up state of specific infocommunication system. The author showed the possibility of constructive combination of graph representation of structure of the object of research and a logic probable analysis method of its reliability indices through uniform set-theoretic representation of its elements and processes proceeding in them.

  19. The CMC/3DPNS computer program for prediction of three-dimensional, subsonic, turbulent aerodynamic juncture region flow. Volume 3: Programmers' manual

    Science.gov (United States)

    Orzechowski, J. A.

    1982-01-01

    The CMC fluid mechanics program system was developed to transmit the theoretical evolution of finite element numerical solution methodology, applied to nonlinear field problems into a versatile computer code for comprehensive flow field analysis. A detailed view of the code from the standpoint of a computer programmer's use is presented. A system macroflow chart and detailed flow charts of several routines necessary to interact with a theoretican/user to modify the operation of this program are presented. All subroutines and details of usage, primarily for input and output routines are described. Integer and real scalars and a cross reference list denoting subroutine usage for these scalars are outlined. Entry points in dynamic storage vector IZ; the lengths of each vector accompanying the scalar definitions are described. A listing of the routines peculiar to the standard test case and a listing of the input deck and printout for this case are included.

  20. Effect of strain on viscoelastic behavior of fresh, swelled and mineralized PVP-CMC hydrogel

    Science.gov (United States)

    Saha, Nabanita; Vyroubal, Radek; Shah, Rushita; Kitano, Takeshi; Saha, Petr

    2013-04-01

    Mineralization of calcium carbonate (CaCO3) in hydrogel matrix is one of the most interesting topics of research by material scientists for the development of bio-inspired polymeric biomaterial for biomedical applications especially for bone tissue regeneration. As per our knowledge there was no work reported about rheological properties of CaCO3 mineralized hydrogel though some works have done on mineralization of CaCO3 in various gel membranes, and also it was reported about the viscoelastic properties of Agarose, Cellulose, PVA and PVPCMC hydrogels. This paper mainly focuses about the effect of strain on viscoelastic properties of fresh, swelled and mineralized (CaCO3) PVP-CMC hydrogel. All these three types of hydrogel sustain (or keep) strictly the elastic properties when low strain (1%) is applied, but at higher strain (10%) the viscoelastic moduli (G' and G") show significant change, and the nature of these materials turned from elastic to viscous.

  1. Electrical Resistance of SiC/SiC Ceramic Matrix Composites for Damage Detection and Life-Prediction

    Science.gov (United States)

    Smith, Craig; Morscher, Gregory; Xia, Zhenhai

    2009-01-01

    Ceramic matrix composites (CMC) are suitable for high temperature structural applications such as turbine airfoils and hypersonic thermal protection systems due to their low density high thermal conductivity. The employment of these materials in such applications is limited by the ability to accurately monitor and predict damage evolution. Current nondestructive methods such as ultrasound, x-ray, and thermal imaging are limited in their ability to quantify small scale, transverse, in-plane, matrix cracks developed over long-time creep and fatigue conditions. CMC is a multifunctional material in which the damage is coupled with the material s electrical resistance, providing the possibility of real-time information about the damage state through monitoring of resistance. Here, resistance measurement of SiC/SiC composites under mechanical load at both room temperature monotonic and high temperature creep conditions, coupled with a modal acoustic emission technique, can relate the effects of temperature, strain, matrix cracks, fiber breaks, and oxidation to the change in electrical resistance. A multiscale model can in turn be developed for life prediction of in-service composites, based on electrical resistance methods. Results of tensile mechanical testing of SiC/SiC composites at room and high temperatures will be discussed. Data relating electrical resistivity to composite constituent content, fiber architecture, temperature, matrix crack formation, and oxidation will be explained, along with progress in modeling such properties.

  2. Thermomechanical Characterization of SiC Fiber Tows and Implications for CMC

    Science.gov (United States)

    Yun, H. M.; DiCarlo, J. A.

    1999-01-01

    In order to better understand SiC fiber behavior within CMC microstructures, mechanical tests were performed on multifilament tows consisting of different types of as produced and pretreated fibers. Tensile strengths of tows and single fibers were measured at room temperature for nonstoichiometric Hi-Nicalon and ZMI fibers and for stoichiometric Hi-Nicalon-S, Tyranno SA. and Sylramic fibers. Based on simple bundle theory, measured strengths for as-produced and sized tows were in general agreement with the single fiber results. However, after sizing removal under inert conditions, tow strengths for the coarser grained stoichiometric fibers were typically lower than those predicted from individual fiber data. This effect is attributed to enhanced fiber-fiber mechanical interaction caused by sizing removal from the rough surfaces of these fibers. In support of this, tow strengths remained high for those fiber types with fine grains or excess surface carbon; and, when re-coated with a BN interphase coating, tow strengths for the coarser grained fibers returned to their as-produced values. When the tows were pretreated in air at intermediate temperatures, tow strengths decreased in a manner that could be correlated with the oxidation characteristics of each fiber type as measured by thermogravimetric analysis. The creep and rupture properties of Hi-Nicalon and Sylramic tows were also measured in air and argon from 1200 to 1400 C. Although displaying transient and environmental effects similar to single fibers, the tows crept faster at short times and slower at long times. This resulted in the tow rupture strengths at long time being much greater than the rupture strengths of single fibers. The CMC implications of the tow results are discussed, as well as the benefits and limitations of tow testing.

  3. The Equilibrium Compositions of Methanol Synthesis System by Cornstalk Syngas

    Science.gov (United States)

    Zhu, Ling-feng; Zhao, Qing-ling; Wang, Yang-yang; Chen, Jing; Zhang, Le; Zhang, Run-tao; Liu, Li-li; Zhang, Zhao-yue

    2010-11-01

    Methanol can be used as a promising alternative for conventional gasoline and Diesel fuel. It is necessary to decompose biomass such as cornstalks in order to produce methanol which is a raw material from agricultural residues. A promising route for processing cornstalks is firstly to gasify cornstalks with thermo-chemical method to prepare the syngas, which can be conducted under a down-flow fixed bed gasifier. The low-heat-value cornstalk syngas produced in this way needs purification and a variety of technical procedures such as deoxygenation, desulfurization, catalytic cracking of tar and hydrogenation. In this paper, the catalytic experiments of methanol synthesis with cornstalk syngas were carried out in a tubular-flow integral and isothermal reactor. The effect such as reaction temperature, pressure, catalyst types, catalyst particle size, syngas flow at entering end and composition of syngas was investigated. Moreover, the equilibrium constants (Kf1, Kf2, KP1, KP2), equilibrium compositions and the concentrations of each part of the equilibrium system for methanol synthesis were calculated by SHBWR state equation under given reaction pressure. The results provided basic data for the design of the industrial equipments in which catalyzed synthesis of methanol from cornstalk gases is operated.

  4. Composition law of κ-entropy for statistically independent systems.

    Science.gov (United States)

    Kaniadakis, G; Scarfone, A M; Sparavigna, A; Wada, T

    2017-05-01

    The intriguing and still open question concerning the composition law of κ-entropy S_{κ}(f)=1/2κ∑_{i}(f_{i}^{1-κ}-f_{i}^{1+κ}) with 0<κ<1 and ∑_{i}f_{i}=1 is here reconsidered and solved. It is shown that, for a statistical system described by the probability distribution f={f_{ij}}, made up of two statistically independent subsystems, described through the probability distributions p={p_{i}} and q={q_{j}}, respectively, with f_{ij}=p_{i}q_{j}, the joint entropy S_{κ}(pq) can be obtained starting from the S_{κ}(p) and S_{κ}(q) entropies, and additionally from the entropic functionals S_{κ}(p/e_{κ}) and S_{κ}(q/e_{κ}),e_{κ} being the κ-Napier number. The composition law of the κ-entropy is given in closed form and emerges as a one-parameter generalization of the ordinary additivity law of Boltzmann-Shannon entropy recovered in the κ→0 limit.

  5. Dietary carbohydrate composition can change waste production and biofilter load in recirculating aquaculture systems

    NARCIS (Netherlands)

    Meriac, A.; Eding, E.H.; Schrama, J.W.; Kamstra, A.; Verreth, J.A.J.

    2014-01-01

    This study investigated the effect of dietary carbohydrate composition on the production, recovery and degradability of fecal waste from rainbow trout (Oncorhynchus mykiss) in recirculating aquaculture systems (RAS). Dietary carbohydrate composition was altered by substituting starch with non-starch

  6. Ceramic Composite Mechanical Fastener System for High-Temperature Structural Assemblies Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Under Phase I, the feasibility of a novel thermal stress-free ceramic composite mechanical fastener system suitable for assembly of high-temperature composite...

  7. Composites by rapid prototyping technology

    CSIR Research Space (South Africa)

    Kumar, S

    2010-02-01

    Full Text Available powder is a fiber, problems of manufacturing occur. The method has also been used to make Metal Matrix Composite (MMC), e.g Fe and graphite [17], WC-Co [18,19], WC-Co and Cu [20,21], Fe, Ni and TiC [22] etc and Ceramic Matrix Composite (CMC) e.g. Si... of various materials used. Key words: : Rapid Prototyping (RP), Laser, Composites 1 Introduction Rapid Prototyping (RP) initially focussed on polymers. These were later re- placed/supplemented by ceramics, metals and composites. Composites are used in RP...

  8. The composition of Solar system asteroids and Earth/Mars moons, and the Earth-Moon composition similarity

    Science.gov (United States)

    Mastrobuono-Battisti, Alessandra; Perets, Hagai B.

    2017-08-01

    In the typical giant-impact scenario for the formation of the Moon, most of the Moon's material originates from the impactor. Any Earth-impactor composition difference should, therefore, correspond to a comparable Earth-Moon composition difference. Analysis of Moon rocks shows a close Earth-Moon composition similarity, posing a challenge for the giant-impact scenario, given that impactors were thought to significantly differ in composition from the planets they impact. However, our recent analysis of 40 planet formation simulations has shown that the oxygen isotope composition difference in Earth-Moon-like systems is consistent with observations for a significant fraction of the cases, thereby potentially resolving the composition similarity challenge. Here, we use a larger set of 140 simulations and improved statistical analysis to further explore this issue. We find that in 4.9-18.2 per cent (1.9-6.7 per cent) of the cases, the resulting composition of the Moon is in agreement with the observed value of Δ17O composition similarity could be resolved to arise from the primordial Earth-impactor composition similarity. We also explore the composition of giant-impact formed Mars' moons as well as Vesta-like asteroids. We predict that the Mars-moon composition difference should be large, but smaller than expected if the moons are captured asteroids. Finally, we find that the leftover planetesimals ('asteroids') in our simulations are frequently scattered far away from their initial positions, thus potentially explaining the mismatch between the current position and composition of the Vesta asteroid.

  9. Experimental study on beam for composite CES structural system

    Science.gov (United States)

    Matsui, Tomoya

    2017-10-01

    Development study on Concrete Encase Steel (CES) composite structure system has been continuously conducted toward the practical use. CES structure is composed of steel and fiber reinforced concrete. In previous study, it was found that CES structure has good seismic performance from experimental study of columns, beam - column joints, shear walls and a two story two span frame. However, as fundamental study on CES beam could be lacking, it is necessary to understand the structural performance of CES beam. In this study, static loading tests of CES beams were conducted with experimental valuable of steel size, the presence or absence of slab and thickness of slab. And restoring characteristics, failure behavior, deformation behavior, and strength evaluation method of CES beam were investigated. As the results, it was found that CES beam showed stable hysteresis behavior. Furthermore it was found that the flexural strength of the CES beam could be evaluated by superposition strength theory.

  10. Development of Metal Matrix Composites for NASA's Advanced Propulsion Systems

    Science.gov (United States)

    Lee, J.; Elam, S.

    2001-01-01

    The state-of-the-art development of several Metal Matrix Composites (MMC) for NASA's advanced propulsion systems will be presented. The goal is to provide an overview of NASA-Marshall Space Flight Center's on-going activities in MMC components for advanced liquid rocket engines such as the X-33 vehicle's Aerospike engine and X-34's Fastrac engine. The focus will be on lightweight, low cost, and environmental compatibility with oxygen and hydrogen of key MMC materials, within each of NASA's new propulsion application, that will provide a high payoff for NASA's Reusable Launch Vehicles and space access vehicles. In order to fabricate structures from MMC, effective joining methods must be developed to join MMC to the same or to different monolithic alloys. Therefore, a qualitative assessment of MMC's welding and joining techniques will be outlined.

  11. Gauge invariance and Compton scattering from relativistic composite systems

    Energy Technology Data Exchange (ETDEWEB)

    Ito, H. [George Washington Univ., Washington, DC (United States). Center for Nuclear Studies; Gross, F. [Continuous Electron Beam Accelerator Facility, Newport News, VA (United States)]|[College of William and Mary, Williamsburg, VA (United States). Dept. of Physics

    1993-09-01

    Using the Ward-Takahashi (W-T) identity and the Bethe-Salpeter (B-S) wave equation, we investigate the dynamical requirements imposed by electromagnetic gauge invariance on Compton scattering from relativistic composite system. The importance of off-shell rescattering in intermediate states, which is equivalent to final state interactions in inclusive processes, is clarified in the context of current conservation. It is shown that, if the nuclear force is nonlocal, there will be both two-photon interaction currents and rescattering contributions to terms involving one-photon interaction currents. We derive the two-body W-T identity for the two-photon interaction currents, and obtain explicit forms for the interaction current operators for three illustrative models of nuclear forces: (a) two-pion exchange forces with baryon resonances, (b) covariant separable forces, and (c) charged one-pion exchange.

  12. Compositions, methods, and systems comprising fluorous-soluble polymers

    Science.gov (United States)

    Swager, Timothy M.; Lim, Jeewoo; Takeda, Yohei

    2015-10-13

    The present invention generally relates to compositions, methods, and systems comprising polymers that are fluorous-soluble and/or organize at interfaces between a fluorous phase and a non-fluorous phase. In some embodiments, emulsions or films are provided comprising a polymer. The polymers, emulsions, and films can be used in many applications, including for determining, treating, and/or imaging a condition and/or disease in a subject. The polymer may also be incorporated into various optoelectronic device such as photovoltaic cells, organic light-emitting diodes, organic field effect transistors, or the like. In some embodiments, the polymers comprise pi-conjugated backbones, and in some cases, are highly emissive.

  13. Harmonised information exchange between decentralised food composition database systems

    DEFF Research Database (Denmark)

    Pakkala, Heikki; Christensen, Tue; Martínez de Victoria, Ignacio

    2010-01-01

    to those network nodes linked to the EuroFIR Web Services that will most likely have the requested information. The retrieved FCD are compiled into a specifically designed data interchange format (the EuroFIR Food Data Transport Package) in XML, which is sent back to the EuroFIR eSearch facility......Background/Objectives: The main aim of the European Food Information Resource (EuroFIR) project is to develop and disseminate a comprehensive, coherent and validated data bank for the distribution of food composition data (FCD). This can only be accomplished by harmonising food description and data...... documentation and by the use of standardised thesauri. Subjects/Methods: The data bank is implemented through a network of local FCD storages (usually national) under the control and responsibility of the local (national) EuroFIR partner. Results: The implementation of the system based on the Euro...

  14. Teasing apart the effect of visibility and physical co-presence to examine the effect of CMC on interpersonal attraction

    NARCIS (Netherlands)

    Croes, Emmelyn; Antheunis, Marjolijn; Schouten, Alexander; Krahmer, Emiel

    2016-01-01

    This study analyzed the possible difference in interpersonal attraction between communicators in cue-rich computer-mediated communication (CMC) and face-to-face (FtF) communication. The first aim was to determine whether physical co-presence and visibility may account for differences in

  15. How did they use it? The involvement of computer science students in a CMC environment created for distance learning

    Directory of Open Access Journals (Sweden)

    Denise Whitelock

    1997-01-01

    Full Text Available Discussione del coinvolgimento degli studenti di informatica in un ambiente Computer Mediated Communucation creato per l’apprendimento a distanza. Le differenti possibilita’ di utilizzo della CMC nell’educazione a distanza e le ragioni per farlo: Apprendimento, Motivazione, Socialita’. Che cosa e’ piu’ importante per gli studenti?

  16. Plant species potentially useful in the phytostabilization process for the abandoned CMC mining site in northern Cyprus.

    Science.gov (United States)

    Cetinkaya, Gulay; Sozen, Nur

    2011-08-01

    The Cupper Mining Company (CMC)'s site located in Lefke-Gemikonagi, Northern Cyprus has been a continuous source of highly dangerous contamination for the surrounding environment, the Lefke region, and the neighboring ecosystems and settlements. Rehabilitation and reuse possibilities of the CMC site due to its vital importance have kept its place in the agenda of Northern Cyprus. Phytostabilization appears to be a convenient and less expensive method that can immediately be used for reducing the negative impacts of the mining site on the region. The main purpose of this study is to identify potential candidate plant species, adapted to grow on polluted sites, for revegetation in the CMC site. Within this context, the method of the study can be summarized as follows: literature review for examining potential candidate plant species for pyhtostabilization in arid and semiarid regions, especially the ones suitable both for the existing ecological and present conditions of Cyprus; identification of native and/or cultural plant species survived in the heavily polluted mining site, and definition of a number of candidate plant species for the study site. The result of sampling revealed that 23 plant species thrive well in the contaminated site. As a result of the literature review and considering drought, metal, salt tolerant features of semiarid environment in the region, 5 tree, 4 shrub, and 23 herbaceous plant species were proposed for starting revegetation with the purpose of phytostabilization on the CMC mining site.

  17. Establishing an Empirical Link between Computer-Mediated Communication (CMC) and SLA: A Meta-Analysis of the Research

    Science.gov (United States)

    Lin, Huifen

    2014-01-01

    Drawing on interactionist and socio-cultural theories, tools provided in computer-mediated communication (CMC) environments have long been considered able to create an environment that shares many communicative features with face-to-face communication. Over the past two decades, researchers have employed a variety of strategies to examine the…

  18. Radiographic Analysis of Simulated First Dorsal Interosseous and Opponens Pollicis Loading Upon Thumb CMC Joint Subluxation: A Cadaver Study.

    Science.gov (United States)

    Adams, Julie E; O'Brien, Virginia; Magnusson, Erik; Rosenstein, Benjamin; Nuckley, David J

    2017-02-01

    Therapy programs to treat thumb carpometacarpal (CMC) arthritis may engage selective activation and reeducation of thenar muscles, particularly the first dorsal interosseous (FDI) and opponens pollicis (OP) to reduce subluxation of the joint. We describe the effect of simulated selective activation of the FDI and OP muscles upon radiographic subluxation of the thumb CMC joint. In a cadaver model of CMC subluxation, loads were applied to the FDI, the OP, and then concomitantly at 0%, 25%, 50%, 75%, and 100% maximal loads and radial subluxation of the joint and reduction in subluxation was measured. Selective activation of the OP, alone, improved the subluxation ratio (SR) in a dose-dependent manner. Selective activation of FDI, alone, demonstrated minimal effects on SR. Concomitant activation of OP and FDI improved the SR across all loading states, and activation of 75% and greater, when compared with FDI activation alone, resulted in a statistically significant improvement in SR to within 10% of the presubluxed joint. Concomitant activation of the FDI and OP acts to reduce subluxation of the thumb CMC joint in a dose-dependent fashion. The OP is likely the predominant reducing force. Hand therapy programs that focus on selective strengthening programs likely function in part to encourage patients to activate the easily palpable and easily understood FDI. Concomitant coactivation of the OP may be the major reducing force to elicit clinical and radiographic reduction of subluxation, improved thumb positioning, and reduction of pain and arthritic symptoms.

  19. Liquefaction processes and systems and liquefaction process intermediate compositions

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Andrew J.; Hart, Todd R.; Billing, Justin M.; Maupin, Gary D.; Hallen, Richard T.; Anderson, Daniel B.

    2014-07-12

    Liquefaction processes are provided that can include: providing a biomass slurry solution having a temperature of at least 300.degree. C. at a pressure of at least 2000 psig; cooling the solution to a temperature of less than 150.degree. C.; and depressurizing the solution to release carbon dioxide from the solution and form at least part of a bio-oil foam. Liquefaction processes are also provided that can include: filtering the biomass slurry to remove particulates; and cooling and depressurizing the filtered solution to form the bio-oil foam. Liquefaction systems are provided that can include: a heated biomass slurry reaction zone maintained above 300.degree. C. and at least 2000 psig and in continuous fluid communication with a flash cooling/depressurization zone maintained below 150.degree. C. and between about 125 psig and about atmospheric pressure. Liquefaction systems are also provided that can include a foam/liquid separation system. Liquefaction process intermediate compositions are provided that can include a bio-oil foam phase separated from an aqueous biomass solids solution.

  20. COMPOSITE

    African Journals Online (AJOL)

    An effective medium theory of ferroelectric ceramic-polymer composite materials which treats both components symmetrically has been investigated to demonstrate the role played by the microgeometry of inclusions on dielectric, mechanical and piezoelectric properties of 0-3 composites. The limits of the various theoretical ...

  1. A Platelet/CMC coupled with offline UPLC-QTOF-MS/MS for screening antiplatelet activity components from aqueous extract of Danshen.

    Science.gov (United States)

    Chen, Ying; Zhang, Na; Ma, Jian; Zhu, Yan; Wang, Meng; Wang, Xiaoming; Zhang, Peng

    2016-01-05

    Platelets play crucial roles in thromboembolic and cardiovascular disease. The main platelets membrane receptors include adenosine diphosphate receptors, thrombin receptors, thromboxane prostanoid receptors and collagen receptors. In this study, a Platelet/CMC coupled with offline UPLC-QTOF-MS/MS system was built to screen antiplatelet activity components from aqueous extract of Danshen, which serve as an agent of antiplatelet aggregation in Traditional Chinese Medicine. Rosmarinic acid, lithospermic acid, salvianolic acid B, two isomers of salvianolic acid B, salvianolic acid C, salvianolic acid D and salvianolic acid H/I were identified as the potential antiplatelet activity components. Moreover, rosmarinic acid, lithospermic acid, salvianolic acid B, salvianolic acid C and danshensu were tested in platelet aggregation in vitro assay. The results suggested their retention time was closely related to the antiplatelet aggregation activities. This study provides a rapid, effective and novel method for screening the potential antiplatelet activity components from Chinese herb medicines. Copyright © 2015. Published by Elsevier B.V.

  2. Composite-step product methods for solving nonsymmetric linear systems

    Energy Technology Data Exchange (ETDEWEB)

    Chan, T.F.; Szeto, T. [Univ. of California, Los Angeles, CA (United States)

    1994-12-31

    The Biconjugate Gradient (BCG) algorithm is the {open_quotes}natural{close_quotes} generalization of the classical Conjugate Gradient method to nonsymmetric linear systems. It is an attractive method because of its simplicity and its good convergence properties. Unfortunately, BCG suffers from two kinds of breakdowns (divisions by 0): one due to the non-existence of the residual polynomial, and the other due to a breakdown in the recurrence relationship used. There are many look-ahead techniques in existence which are designed to handle these breakdowns. Although the step size needed to overcome an exact breakdown can be computed in principle, these methods can unfortunately be quite complicated for handling near breakdowns since the sizes of the look-ahead steps are variable (indeed, the breakdowns can be incurable). Recently, Bank and Chan introduced the Composite Step Biconjugate Gradient (CSBCG) algorithm, an alternative which cures only the first of the two breakdowns mentioned by skipping over steps for which the BCG iterate is not defined. This is done with a simple modification of BCG which needs only a maximum look-ahead step size of 2 to eliminate the (near) breakdown and to smooth the sometimes erratic convergence of BCG. Thus, instead of a more complicated (but less prone to breakdown) version, CSBCG cures only one kind of breakdown, but does so with a minimal modification to the usual implementation of BCG in the hope that its empirically observed stability will be inherited. The authors note, then, that the Composite Step idea can be incorporated anywhere the BCG polynomial is used; in particular, in product methods such as CGS, Bi-CGSTAB, and TFQMR. Doing this not only cures the breakdown mentioned above, but also takes on the advantages of these product methods, namely, no multiplications by the transpose matrix and a faster convergence rate than BCG.

  3. Differential Evolution Based Intelligent System State Search Method for Composite Power System Reliability Evaluation

    Science.gov (United States)

    Bakkiyaraj, Ashok; Kumarappan, N.

    2015-09-01

    This paper presents a new approach for evaluating the reliability indices of a composite power system that adopts binary differential evolution (BDE) algorithm in the search mechanism to select the system states. These states also called dominant states, have large state probability and higher loss of load curtailment necessary to maintain real power balance. A chromosome of a BDE algorithm represents the system state. BDE is not applied for its traditional application of optimizing a non-linear objective function, but used as tool for exploring more number of dominant states by producing new chromosomes, mutant vectors and trail vectors based on the fitness function. The searched system states are used to evaluate annualized system and load point reliability indices. The proposed search methodology is applied to RBTS and IEEE-RTS test systems and results are compared with other approaches. This approach evaluates the indices similar to existing methods while analyzing less number of system states.

  4. Bond strength durability of direct and indirect composite systems following surface conditioning for repair

    NARCIS (Netherlands)

    Passos, Sheila Pestana; Ozcan, Mutlu; Vanderlei, Aleska Dias; Leite, Fabiola Pessoa Pereira; Kimpara, Estevao Tomomitsu; Bottino, Marco Antonio

    2007-01-01

    Purpose: This study evaluated the effect of surface conditioning methods and thermocycling on the bond strength between a resin composite and an indirect composite system in order to test the repair bond strength. Materials and Methods: Eighteen blocks (5 x 5 x 4 mm) of indirect resin composite

  5. Nano-Composite Foam Sensor System in Football Helmets.

    Science.gov (United States)

    Merrell, A Jake; Christensen, William F; Seeley, Matthew K; Bowden, Anton E; Fullwood, David T

    2017-12-01

    American football has both the highest rate of concussion incidences as well as the highest number of concussions of all contact sports due to both the number of athletes and nature of the sport. Recent research has linked concussions with long term health complications such as chronic traumatic encephalopathy and early onset Alzheimer's. Understanding the mechanical characteristics of concussive impacts is critical to help protect athletes from these debilitating diseases and is now possible using helmet-based sensor systems. To date, real time on-field measurement of head impacts has been almost exclusively measured by devices that rely on accelerometers or gyroscopes attached to the player's helmet, or embedded in a mouth guard. These systems monitor motion of the head or helmet, but do not directly measure impact energy. This paper evaluates the accuracy of a novel, multifunctional foam-based sensor that replaces a portion of the helmet foam to measure impact. All modified helmets were tested using a National Operating Committee Standards for Athletic Equipment-style drop tower with a total of 24 drop tests (4 locations with 6 impact energies). The impacts were evaluated using a headform, instrumented with a tri-axial accelerometer, mounted to a Hybrid III neck assembly. The resultant accelerations were evaluated for both the peak acceleration and the severity indices. These data were then compared to the voltage response from multiple Nano Composite Foam sensors located throughout the helmet. The foam sensor system proved to be accurate in measuring both the HIC and Gadd severity index, as well as peak acceleration while also providing additional details that were previously difficult to obtain, such as impact energy.

  6. Composite Materials Design Database and Data Retrieval System Requirements

    Science.gov (United States)

    1991-08-01

    market is a viable development route. However, in order to achieve generality, gateway arrangements are necessary to combine specific databases developed...filamentary composites in woven and nonwoven forms. constituent materials - Individual materials that make up the composite material. cross-ply laminate...woven and nonwoven composite materials. Most common fibers are glass, boron, graphite, and aramid. fiber content - Percent volume of fiber in a

  7. Magnetoelectric phenomena in single-phase and composite systems

    Directory of Open Access Journals (Sweden)

    Mitoseriu, Liliana

    2005-06-01

    Full Text Available In the present review, the main phenomenology and problematic related some of the most interesting magnetoelectric systems (materials having in the same phase magnetic and ferroelectric order and interaction between them, giving rise to the magnetoelectric effect is presented. Some single-phase systems as manganites, BiFeO3 and relaxor magnetoelectrics mainly interesting from a fundamental point of view, as well as diphasic composites with a high potentiality in applications are discussed. The coupling between ferroelectric and magnetic activity in magnetoelectric multiferroics opens the possibility of controlling magnetic properties through electric fields and vice versa, giving to these materials a large potentiality for applications in spintronics, multiple state memory elements or novel memory devices which might use electric and/or magnetic fields for read/write operations.

    En esta revisión, se presentan la fenomenología y principales problemas relacionados con los sistemas magnetoeléctricos más interesantes. En el efecto magnetoeléctrico el orden magnético y ferroeléctrico se dan en una misma fase con interacción entre ellos. Se abordan sistemas monobásicos como manganitas, BiFeO3 y magnetoeléctricos relaxores y composites difásicos que poseen tanto un interés desde el punto de vista fundamental como un alto potencial de aplicaciones. El acoplamiento entre la actividad ferroeléctrica y magnética en multiferróicos magnetoeléctricos abre la posibilidad de controlar las propiedades magnéticas a través de campos eléctricos y viceversa, dotando a estos materiales de numerosas aplicaciones en espintrónica, elementos de memoria de estados múltiples o novedosas aplicaciones de memoria que pueden emplear campos eléctricos y/o magnéticos en operaciones de lectura/escritura.

  8. "The refer less resolve more" initiative: A five-year experience from CMC Vellore, India

    Directory of Open Access Journals (Sweden)

    Jachin Velavan

    2012-01-01

    Full Text Available India′s one billion plus strong population presents huge health care needs. Presently, approximately 250,000 general practitioners and 30,000 Government doctors are a part of the Indian healthcare workforce, but 80% of them are based in urban India. Problems which plague healthcare delivery and attributed to physician practice may be enumerated as - physicians (1 lack competencies, (2 lack updating, (3 prescribe irrationally (pressures from pharmaceutical companies and patients, (4 practice unethically, (5 refer excessively to specialists and other clinical professionals, and (6 investigate for diseases without justification. A multi-competent Family Physician who could provide a single-window, ethical, and holistic healthcare to patients and families is the need of the hour. Therefore, training, equipping, and empowering these 250,000 doctors to become such physicians will reduce health costs considerably. Distance medical education using all the andragogic methods can be used to train large number of individuals without displacing them from their work-places. Distance learning provides a useful interface for rapidly developing a specialized pool of doctors practicing and advocating family medicine as most-needed discipline. This motivated CMC Vellore, a premier institution for medical education in India, to start a the "refer less resolve more initiative" by offering "two year family medicine diploma course" by distance mode. This is an innovatively-written program consisting of problem-based self-learning modules, video-lectures, video-conferencing, and face-to-face contact programs. Ten secondary level hospitals, across the country, under the supervision of national and international family medicine faculty form the pillars of this program. This distance learning program offered by CMC Vellore has become the platform for change as there is special focus is on ethics, rational prescribing, consultation skills, application of family medicine

  9. Improved Joining of Metal Components to Composite Structures

    Science.gov (United States)

    Semmes, Edmund

    2009-01-01

    Systems requirements for complex spacecraft drive design requirements that lead to structures, components, and/or enclosures of a multi-material and multifunctional design. The varying physical properties of aluminum, tungsten, Invar, or other high-grade aerospace metals when utilized in conjunction with lightweight composites multiply system level solutions. These multi-material designs are largely dependent upon effective joining techAn improved method of joining metal components to matrix/fiber composite material structures has been invented. The method is particularly applicable to equipping such thin-wall polymer-matrix composite (PMC) structures as tanks with flanges, ceramic matrix composite (CMC) liners for high heat engine nozzles, and other metallic-to-composite attachments. The method is oriented toward new architectures and distributing mechanical loads as widely as possible in the vicinities of attachment locations to prevent excessive concentrations of stresses that could give rise to delaminations, debonds, leaks, and other failures. The method in its most basic form can be summarized as follows: A metal component is to be joined to a designated attachment area on a composite-material structure. In preparation for joining, the metal component is fabricated to include multiple studs projecting from the aforementioned face. Also in preparation for joining, holes just wide enough to accept the studs are molded into, drilled, or otherwise formed in the corresponding locations in the designated attachment area of the uncured ("wet') composite structure. The metal component is brought together with the uncured composite structure so that the studs become firmly seated in the holes, thereby causing the composite material to become intertwined with the metal component in the joining area. Alternately, it is proposed to utilize other mechanical attachment schemes whereby the uncured composite and metallic parts are joined with "z-direction" fasteners. The

  10. Leakage testing for different adhesive systems and composites to ...

    African Journals Online (AJOL)

    The teeth were randomly assigned to six groups of 14 teeth each as follows: The first group – etch‑rinse adhesive applied and cavities filled with flowable composite, the second group – etch‑rinse adhesive applied and cavities filled with bulk‑fill resin composite, the third group – one‑stage self‑etch (SE) adhesive applied ...

  11. Composite order bilinear pairing on elliptic curve for dual system encryption

    Science.gov (United States)

    Latiff, Fatin Nabila Abd; Othman, Wan Ainun Mior

    2015-10-01

    In this paper, we explore the pairing-based cryptography on elliptic curve. The security of protocols using composite order bilinear pairing on elliptic curve depends on the difficulty of factoring the number N. Here, we show how to construct composite ordinary pairing-friendly elliptic curve having the subgroup of composite order N by using Cocks-Pinch Method. We also introduce dual system encryption to transform Identity-Based Encryption (IBE) scheme built over prime-order bilinear, to composite order bilinear groups. The new Identity-Based Encryption (IBE) is secured since it uses the Dual System Encryption methodology which guaranteed full security of the new IBE system.

  12. Composition.

    Science.gov (United States)

    Communication: Journalism Education Today, 2002

    2002-01-01

    Considers how photography is more than just pointing a camera in the right direction. Explains that good pictures use elements of composition such as the Rule of Thirds, leading lines, framing and repetition of shapes. Presents 16 photographs from college and secondary school publications, and describes the techniques that makes them effective.…

  13. Improving the compatibility of an Y-TZP/porcelain system using a new composite interlayer composition.

    Science.gov (United States)

    Passos, Sheila P; Linke, Bernie; Major, Paul W; Nychka, John A

    2017-01-01

    The aim of this study was to evaluate the effects of different cooling procedures and a new composite interlayer composition on the flexural strength, and veneer delamination resistance, of an all-ceramic veneered translucent Y-TZP core. One hundred twenty bar-shaped specimens of a translucent Y-TZP ceramic were prepared and divided into three groups: (1) no composite interlayer; (2) a glass interlayer (silica-based glass); (3) a mixed composite interlayer of glass and porcelain veneer material. A veneering porcelain (with and without a composite interlayer) was applied on the specimen surface and sintered. Each core-veneer group was cooled using a rapid or a slow cooling rate. All specimens were tested in four-point bending. Data were statistically analyzed using two-way ANOVA, followed by Post-Hoc tests with Bonferroni correction (α=0.05) and Weibull analysis. The group with no interlayer using the rapid cooling technique exhibited the highest flexural strength. However, with low reliability and the greatest delaminated area of porcelain under tension. A glass interlayer between porcelain veneer and zirconia core presents as a good alternative for maintaining flexural strength and porcelain veneer delamination resistance in zirconia based restorations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Direct measurements of non-ionic attraction and nanoscaled lubrication in biomimetic composites from nanofibrillated cellulose and modified carboxymethylated cellulose

    Science.gov (United States)

    Olszewska, Anna; Valle-Delgado, Juan José; Nikinmaa, Miika; Laine, Janne; Österberg, Monika

    2013-11-01

    There is a growing interest to design biomimetic self-assembled composite films from renewable resources aimed at a combination of high toughness, strength and stiffness. However, the relationship between interfacial interactions of the components and the mechanical performance of the composite is still poorly understood. In this work we present evidence of the link between mechanical performance of carbohydrate-based composites with nanolubrication and with direct surface forces between the hard and soft domain in the system. Our approach was to use nanofibrillated cellulose (NFC) as the major reinforcing domain and to modify it by adsorption of a small amount of soft polyethylene glycol grafted carboxymethyl cellulose (CMC-g-PEG). The effect of the soft polymer on direct normal and friction forces in air between cellulose surfaces was evaluated using colloidal probe microscopy. The fibrillar structure of the NFC thin film affected the frictional behaviour; when decreasing load, the friction between pure cellulose surfaces increased, suggesting partial pull-out of fibrils, a phenomenon not observed for non-fibrillar cellulose substrates. Adsorption of CMC-g-PEG on both surfaces decreased the friction considerably but adhesion was still high. The symmetric system, having both cellulose substrates covered with the polymer, was compared to asymmetric systems where only one surface was covered with the polymer. Furthermore, a free standing composite film was prepared by non-ionic self-assembly of NFC and CMC-g-PEG with 99 : 1 weight-ratio; the mechanical properties of the macroscopic films were related to the nanoscaled interactions between the components. The composition studied showed excellent mechanical properties which do not follow the simple rule of mixture. Thus, a synergy in the direct surface forces and mechanical properties was found. This approach offers a robust path to aid in the efficient design of next generation biomimetic composites.There is a

  15. The effectiveness of orthoses in the conservative management of thumb CMC joint osteoarthritis: An analysis of functional pinch strength.

    Science.gov (United States)

    Grenier, Marie-Lyne; Mendonca, Rochelle; Dalley, Peter

    2016-01-01

    The study was a retrospective cohort analysis for a 19-month period from May 2013 to December 2014. Although the use of orthoses has long been a staple of conservative treatment measures for individuals with osteoarthritis of the thumb carpometacarpal (CMC) joint, there remains little evidence exploring its effectiveness in improving functional outcomes for this client population. The purpose of this study was to assess the effectiveness of 3 frequently used orthoses in improving the functional pinch strength of adults with a diagnosis of thumb CMC joint osteoarthritis. A retrospective cohort analysis was conducted to determine whether pinch strength improved after orthotic fabrication, and fitting in patients referred to a hand therapy clinic. Patients who received a Colditz design orthosis had a mean increase of 2.64 lb with regard to functional pinch strength after orthotic fabrication and fitting. Patients who received a Comfort Cool orthosis (North Coast Medical, Morgan Hill, CA) had a mean increase of 2.47 lb, whereas patients who received a Thumb Spica orthosis had a mean increase of 3.25 lb. There was no evidence of any statistically significant difference in the average improvements in pinch strength between the Colditz design orthosis and the Comfort Cool orthosis. Results from this study demonstrate that orthosis wear consistently increases the functional pinch strength of individuals with thumb CMC joint osteoarthritis. Large-scale multisite research studies comparing various orthotic designs are necessary to help therapists determine best practice interventions for the conservative management of thumb CMC joint osteoarthritis. 2(c). Copyright © 2016 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

  16. When talking about the Spanish curricula of the CMC, do we all Autonomous Communities talk about the same matter?

    Directory of Open Access Journals (Sweden)

    Tárraga Poveda, Pilar

    2013-01-01

    Full Text Available In the present paper we aim at comparing the Spanish curricula of the subject CMC -“Ciencias para el Mundo Contemporáneo” (Science for Contemporary World of High School. We have revised the documents of the different Autonomous Communities (different regions concerning the function of subject matter, methodological orientation, evaluation criteria, and developmment of competence. We have found differences suggesting that at the curriculum level we do not always talk about the same matter.

  17. Effect of finishing system on carcass characteristics and composition ...

    African Journals Online (AJOL)

    Martina Muller

    2013-09-18

    Sep 18, 2013 ... hind-limb length and maximum hind limb width. Tissue ... yield high quantities of meat (Mahgoub et al., 2012). Traits such as ... supplementation improves both composition and carcass quality of goats. ... Panicum maximum.

  18. Autonomous Composite Fan Containment Integrity Monitoring (AUTOCONFIRM) System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — New engine fan blade containment structures are being manufactured with advanced composite structures such that they can withstand blade-out events. The use of...

  19. Screening of allergic components mediated by H(1)R in homoharringtonine injection through H(1)R/CMC-HPLC/MS.

    Science.gov (United States)

    Guo, Ying; Han, Shengli; Cao, Jingjing; Liu, Qi; Zhang, Tao

    2014-12-01

    It has been reported that the histamine H1 receptor (H(1)R) gene is up-regulated in patients with allergic rhinitis and H(1)R expression level strongly correlates with the severity of allergy symptoms. Drugs for therapy should avoid allergy symptoms, especially for patients with over-expressed H(1)R. Therefore, screening of the components which could induce H(1)R activation is urgently needed for drug safety evaluation. Homoharringtonine injection is a preparation for acute nonlymphocytic leukemia, which is approved by China Food and Drug Administration (CFDA) and US Food and Drug Administration. However, severely adverse reactions often occur with intravenous injection of the preparation. In present study, an H(1)R/CMC model was applied for capturing membrane retained components which could induce H(1)R activation. Retention components were enriched and analyzed by H(1)R/CMC-HPLC/MS. Homoharringtonine was recognized, separated and identified in homoharringtonine injection. Ca(2+) flux assay and p-IP3R expression founded that homoharringtonine retained by the H1 R/CMC model increased phosphorylation of IP3R and promoted cytosolic free Ca(2+) elevation in a dose-dependent manner which further verified the activity of homoharringtonine in activating the H1 R. In conclusion, homoharringtonine was screened and identified as a potential allergic factor. This provides an indication that a patient with over-expressed H1 R should be aware of possible allergic reaction when applying homoharringtonine injection. Copyright © 2014 John Wiley & Sons, Ltd.

  20. Dynamic and equilibrium studies of the RDX removal from soil using CMC-coated zerovalent iron nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Naja, Ghinwa [Department of Chemical Engineering, Faculty of Engineering, McGill University, Montreal, Quebec, H3A 2B2 (Canada); Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec, H4P 2R2 (Canada); Everglades Foundation, Science Department, Palmetto Bay, FL 33157 (United States); Apiratikul, Ronbanchob [Department of Chemical Engineering, Faculty of Engineering, McGill University, Montreal, Quebec, H3A 2B2 (Canada); Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec, H4P 2R2 (Canada); Department of Environmental Science, Faculty of Science and Technology, Suan Sunandha Rajabhat University, Bangkok 10300 (Thailand); Pavasant, Prasert [Department of Chemical engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330 (Thailand); Volesky, Bohumil [Department of Chemical Engineering, Faculty of Engineering, McGill University, Montreal, Quebec, H3A 2B2 (Canada); Hawari, Jalal, E-mail: jalal.hawari@nrc.c [Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec, H4P 2R2 (Canada)

    2009-08-15

    Rapid chemical degradation of toxic RDX explosive in soil can be accomplished using zerovalent nanoiron suspension stabilized in dilute carboxymethyl cellulose solution (CMC-ZVINs). The effect of operating conditions (redox-potential, Fe/RDX molar ratio) was studied on batchwise removal of RDX in contaminated soil. While anaerobic conditions resulted in 98% RDX removal in 3 h, only slightly over 60% RDX removal could be attained under aerobic conditions. The molar ratio did not have any influence on the intermediate and final RDX degradation products (methylenedinitramine, nitroso derivative, N{sub 2}, N{sub 2}O, NO{sub 2}{sup -}), however, their distribution changed. Dynamic studies were conducted using a flow-through short column packed with RDX-contaminated soil and fed with CMC-ZVINs. The column was operated at two interstitial velocities (2.2 and 1.6 cm min{sup -1}), resulting in the 76.6% and 95% removal of the initial RDX soil contamination load (60 mg kg{sup -1}), respectively. While the column operating conditions could be further optimized, 95% of the RDX initially present in the contaminated soil packed in the column was degraded when flushed with a CMC-ZVINs suspension in this work. - RDX chemical degradation in a contaminated soil was conducted using coated zerovalent iron nanoparticles in both batch and dynamic column studies.

  1. Effects of Fiber/Matrix Interface and its Composition on Mechanical Properties of Hi Nicalon/Celsian Composites

    Science.gov (United States)

    Bansal, Narottam P.; Eldridge, Jeffrey I.

    1998-01-01

    Fiber-reinforced ceramic matrix composites (CMC) are prospective candidate materials for high temperature structural applications in aerospace, energy conservation, power generation, nuclear, petrochemical, and other industries. At NASA Lewis, we are investigating celsian matrix composites reinforced with various types of silicon carbide fibers. The objective of the present study was to investigate the effects of fiber/matrix interface and its composition on the mechanical properties of silicon carbide (Hi-Nicalon) fiber-reinforced celsian matrix composites.

  2. Influence of composition on the adhesive strength and initial viscosity of denture adhesives.

    Science.gov (United States)

    Han, Jian-min; Hong, Guang; Hayashida, Kentaro; Maeda, Takeshi; Murata, Hiroshi; Sasaki, Keiichi

    2014-01-01

    To investigate the effect of composition on the initial viscosity and adhesive strength between denture adhesives and the denture base. Two types of water-soluble polymers (methoxy ethylene maleic anhydride copolymer [PVM-MA] and sodium carboxymethyl cellulose [CMC]) were used. Samples were divided into three groups. Group 1 contained only PVM-MA; Group 2 contained only CMC; and Group 3 contained PVM-MA and CMC. The initial viscosity and adhesive strength were measured. For Group 1, the initial viscosity increased significantly as PVM-MA content increased. The adhesive strength of Group 1 lasted longer than Group 2. The adhesive strength of Group 3 varied greatly. The ratio of CMC and PVM-MA has a significant effect on the initial viscosity and adhesive strength of denture adhesives. Our results suggest that it is possible to improve the durability of a denture adhesive by combining different water-soluble polymers.

  3. White and Red Light Photoluminescence of ZnS:Eu3+ - CMC Nanophosphors

    Science.gov (United States)

    Ikorkya, Ahemen; de, Dilip; Meludu, Osita; Bruno, V.

    2015-03-01

    White and red photoluminescence based on europium-doped zinc sulfide nanocrystals capped with sodium carboxymethyl cellulose (ZnS: Eu3+ - CMC) was synthesized using precipitation technique with Eu3+ ions doping concentrations of 1 mol% and 5 mol%. Some portions of the doped samples were annealed at 300 °C in a sulfur-rich atmosphere. All samples show cubic (zinc blende) structure with crystal sizes; 2.56 nm and 2.91 nm, for the as-synthesized samples, 4.35 nm and 3.65 nm for thermally treated samples, respectively. The as-synthesized samples have equal energy band gap of 4.2 eV, but decreased to 3.76 eV and 3.81 eV after heat treatment. Photoluminescence studies indicate defect emission bands and Eu3+ ion lines for the as-synthesized samples. The as-synthesized samples gave pure orange-red emission when excited at wavelength of 394 nm and 465 nm. After thermal annealing of the samples, a broad emission band in the blue-green region assigned to defect related states emerged or were enhanced. Also enhanced were the emission lines of Eu3+ ions in the orange-red region. A combination of these two transitions gave white light of different shades depending on Eu concentration or excitation wavelength. Different shades of white light from cool white through Day-light to warm white light were recorded on the CIE 1931 chromaticity diagram. The source excitation wavelengths range from UV-330 nm through near UV - 396 nm to blue - 465 nm wavelengths which are in the range of InGaN -based LEDs emissions.

  4. Fabrication of CMC-g-PAM Superporous Polymer Monoliths via Eco-Friendly Pickering-MIPEs for Superior Adsorption of Methyl Violet and Methylene Blue

    OpenAIRE

    Wang, Feng; Zhu, Yongfeng; Wang, Wenbo; ZONG, Li; Lu, Taotao; Wang, Aiqin

    2017-01-01

    A series of superporous carboxymethylcellulose-graft-poly(acrylamide)/palygorskite (CMC-g-PAM/Pal) polymer monoliths presenting interconnected pore structure and excellent adsorption properties were prepared by one-step free-radical grafting polymerization reaction of CMC and acrylamide (AM) in the oil-in-water (O/W) Pickering-medium internal phase emulsions (Pickering-MIPEs) composed of non-toxic edible oil as a dispersion phase and natural Pal nanorods as stabilizers. The effects of Pal dos...

  5. Deformation texture development in a model composite system

    Energy Technology Data Exchange (ETDEWEB)

    Poole, W.J.; MacEwen, S.; Kocks, U.F.; Embury, J.D.

    1995-05-01

    Model composites fabricated with a polycrystalline copper matrix and continuous tungsten fibres were deformed in plane strain compression with the fibres perpendicular to the loading axis and parallel to the direction of zero strain. The development of texture in the matrix due to deformation was measured using x-ray diffraction. It was observed that the macroscopic texture development in the composite was weaker than for unreinforced copper. The pattern of deformation in the matrix was quantified using experimental measurements and finite element method calculations. By carefully sectioning the composite after deformation, texture measurements were conducted for regions which exhibited characteristic types of deformation. These measurements showed that there is a variety of local textures (some weaker, some stronger than the texture in the unreinforced matrix) which when summed give the result of a weak global texture. This result is in agreement with the predictions from the computer simulations of Bolmaro et al.

  6. High-Performance Synthetic Fibers for Composites

    Science.gov (United States)

    1992-04-01

    FMI Composites LTD); Formation of fibergLass\\preform for composite coupling shaft; Undulating ribbon structure of graphene layers for a PAN-based c...ropes and cables, heat exchangers, bridge decking, and reinforced concrete . The key to increased consumption in these diverse end uses is reduced raw...cost while increasing their utility through toughening provides the opportunity for expanded CMC usage, such as in cement, concrete , bricks, and tile

  7. Further development of the EUMETNET Composite Observing System (EUCOS)

    Science.gov (United States)

    Klink, S.; Dibbern, J.

    2009-09-01

    EUCOS, which stands for EUMETNET Composite Observing System, is a EUMETNET programme whose main objective is a central management of surface based operational observations on a European-wide scale serving the needs of regional scale NWP. EUMETNET is a consortium of currently 26 national meteorological services in Europe that provides a framework for different operational and developmental co-operative programmes between the services. The work content of the EUCOS Programme includes the management of the operational observing networks, through the E-AMDAR, E-ASAP, E-SURFMAR and E-WINPROF programmes. The coordination of NMSs owned territorial networks (e.g. radiosonde stations and synoptic stations), data quality monitoring, fault reporting and recovery, a studies programme for the evolution of the observing networks and liaison with other organisations like WMO are among the tasks of the programme. The current period of the EUCOS programme has a five year duration (2007-2011) and a two stage approach was proposed in the programme definition. During the transition phase 2007-2008 no new programmatic objectives had been set because amongst others the Space-Terrestrial (S-T) study which investigated the relative contributions of selected space based and ground based observing systems to the forecast skill of global and regional NWP models had to be finalised first. Based on the findings of this study EUCOS currently prepares a redesign of its upper-air network. The original EUCOS upper-air network design was prepared in 2000 in order to define a set of stations serving the common general NWP requirement. Additional considerations were to make it possible to supply a common set of performance standards across the territory of EUMETNET Members and to ensure that the radiosonde network interleaved with AMDAR airports. The EUCOS upper-air network now requires a redesign because of several reasons. There is a need to take into account the significant evolution of the AMDAR

  8. Composite Polymer Derived Ceramic System for Oxidizing Environments

    Energy Technology Data Exchange (ETDEWEB)

    Torrey, Jessica D.; Bordia, Rajendra K.; Henager, Charles H.; Blum, Y.; Shin, Yongsoon; Samuels, William D.

    2006-07-01

    Preceramic polymers and expansion agents are being investigated to process composite ceramic coatings. In this paper, we present results of a systematic approach to selecting the preceramic polymer and expansion agents, and the optimization of the processing parameters to produce composite ceramics. Six commercially available poly(silsesquioxane) polymers and two polysiloxanes were studied. In addition, several metals and intermetallics were considered as potential expansion agents. Based on this study, the most desirable polymer/expansion agent combination and optimal processing parameters have been identified.

  9. The influence of carboxymethylcellulose (CMC) on the reactivity of Fe NPs toward decabrominated diphenyl ether: The Ni doping, temperature, pH, and anion effects.

    Science.gov (United States)

    Tso, Chih-Ping; Shih, Yang-Hsin

    2017-01-15

    Polybrominated diphenyl ethers (PBDEs) are commonly used brominated flame retardants in many products. They have accumulated in the environment and become widely dispersed. In this study, carboxymethylcellulose (CMC) was applied to modify nanoscale zerovalent iron (NZVI) and bimetallic Ni/Fe nanoparticles (NPs) to prevent NP aggregation. In this study the removal kinetics of the decabrominated diphenyl ethers (DBDE) with CMC-stabilized Fe NPs were evaluated. CMC-stabilized Ni/Fe NPs with an average size of 86.7nm contained metallic Fe(0) and reduced Ni. The colloidal stability decreased with a decrease in pH, which was further accompanied by a change in the removal rate of DBDE. Our results showed that anions do not change the removal rates of DBDE, with the exception of 10mM NO3(-), which induced the formation of Fe (hydro)oxides on the Fe NP surface, which could further coagulate with DBDE. This study provides important information for our understanding of the influence of CMC coatings on the reactivity of Fe NPs. Because CMC coatings prevent the passivation of Fe in the presence of anions, CMC-coated Fe NPs show potential for the in-situ remediation of PBDEs in the environment. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Enhanced electrochemical properties of LiFePO4 (LFP) cathode using the carboxymethyl cellulose lithium (CMC-Li) as novel binder in lithium-ion battery.

    Science.gov (United States)

    Qiu, Lei; Shao, Ziqiang; Wang, Daxiong; Wang, Wenjun; Wang, Feijun; Wang, Jianquan

    2014-10-13

    Novel water-based binder CMC-Li is synthesized using cotton as raw material. The mechanism of the CMC-Li as a binder is reported. Electrochemical properties of batteries cathodes based on commercially available lithium iron phosphate (LiFePO4, LFP) and CMC-Li as a water-soluble binder are investigated. CMC-Li is a novel lithium-ion binder. Compare with conventional poly(vinylidene fluoride) (PVDF) binder, and the battery with CMC-Li as the binder retained 97.8% of initial reversible capacity after 200 cycles at 176 mAh g(-1), which is beyond the theoretical specific capacity of LFP. Constant current charge-discharge test results demonstrate that the LFP electrode using CMC-Li as the binder has the highest rate capability, follow closely by that using PVDF binder. The batteries have good electrochemical property, outstanding pollution-free and excellent stability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. CEMCAN Software Enhanced for Predicting the Properties of Woven Ceramic Matrix Composites

    Science.gov (United States)

    Murthy, Pappu L. N.; Mital, Subodh K.; DiCarlo, James A.

    2000-01-01

    Major advancements are needed in current high-temperature materials to meet the requirements of future space and aeropropulsion structural components. Ceramic matrix composites (CMC's) are one class of materials that are being evaluated as candidate materials for many high-temperature applications. Past efforts to improve the performance of CMC's focused primarily on improving the properties of the fiber, interfacial coatings, and matrix constituents as individual phases. Design and analysis tools must take into consideration the complex geometries, microstructures, and fabrication processes involved in these composites and must allow the composite properties to be tailored for optimum performance. Major accomplishments during the past year include the development and inclusion of woven CMC micromechanics methodology into the CEMCAN (Ceramic Matrix Composites Analyzer) computer code. The code enables one to calibrate a consistent set of constituent properties as a function of temperature with the aid of experimentally measured data.

  12. Comparison of Microleakage of Composite Resin Veneering Systems at the Alloy Interface

    Science.gov (United States)

    1988-09-01

    technique that there is leakage around resin veneers in gold crowns. Microleakage studies have been used primarily for the evaluation of direct...investigation is to evaluate the bond between veneering composite resin and metal substructure. Measurement of microleakage at the composite resin-alloy...34OVERPRINT" COMPARISON OF MICROLEAKAGE OF COMPOSITE RESIN VENEERING SYSTEMS AT THE ALLOY INTERFACE A THESIS Presented to the Faculty of The University

  13. Probabilistic Micromechanics and Macromechanics for Ceramic Matrix Composites

    Science.gov (United States)

    Murthy, Pappu L. N.; Mital, Subodh K.; Shah, Ashwin R.

    1997-01-01

    The properties of ceramic matrix composites (CMC's) are known to display a considerable amount of scatter due to variations in fiber/matrix properties, interphase properties, interphase bonding, amount of matrix voids, and many geometry- or fabrication-related parameters, such as ply thickness and ply orientation. This paper summarizes preliminary studies in which formal probabilistic descriptions of the material-behavior- and fabrication-related parameters were incorporated into micromechanics and macromechanics for CMC'S. In this process two existing methodologies, namely CMC micromechanics and macromechanics analysis and a fast probability integration (FPI) technique are synergistically coupled to obtain the probabilistic composite behavior or response. Preliminary results in the form of cumulative probability distributions and information on the probability sensitivities of the response to primitive variables for a unidirectional silicon carbide/reaction-bonded silicon nitride (SiC/RBSN) CMC are presented. The cumulative distribution functions are computed for composite moduli, thermal expansion coefficients, thermal conductivities, and longitudinal tensile strength at room temperature. The variations in the constituent properties that directly affect these composite properties are accounted for via assumed probabilistic distributions. Collectively, the results show that the present technique provides valuable information about the composite properties and sensitivity factors, which is useful to design or test engineers. Furthermore, the present methodology is computationally more efficient than a standard Monte-Carlo simulation technique; and the agreement between the two solutions is excellent, as shown via select examples.

  14. Manufacturing and CMC component development for brake disks in automotive applications

    Energy Technology Data Exchange (ETDEWEB)

    Gadow, R.; Speicher, M. [Institute for Manufacturing Technologies of Ceramic Components and Composites (IFKB), University of Stuttgart (Germany)

    2000-07-01

    Disk brake systems have been developed to high technical standards in the automotive industry since more than 40 years. Hydraulic brake systems for serial passenger cars as well as for trucks and trains include a disk made of cast iron in a variety of sophisticated designs. With appropriate friction properties its wear and corrosion resistance and its high temperature stability are insufficient. For light weight economy cars and improved comfort of vehicle suspension, the total and specific weight of brake components must be lowered. Based on first experiments in aeroplane brakes, carbon fiber composites (CFC) for disk brakes have been developed for competition cars in 2D and 3D design, mainly with metal wheel hub. The high temperature stability and friction behaviour perform superior retardation under extreme conditions. With respect to costs and insufficient all weather braking behaviour, CFC disks cannot be used in serial passenger cars. Their limited oxidation resistance, their critical and non comfortable low temperature retardation, the wear and unsteady friction coefficient show further limitations in industrial use. (orig.)

  15. Thermal properties of composite materials: a complex systems approximation

    Science.gov (United States)

    Carrillo, J. L.; Bonilla, Beatriz; Reyes, J. J.; Dossetti, Victor

    We propose an effective media approximation to describe the thermal diffusivity of composite samples made of polyester resin and magnetite inclusions. By means of photoacoustic spectroscopy, the thermal diffusivity of the samples were experimentally measured. The volume fraction of the inclusions was systematically varied in order to study the changes in the effective thermal diffusivity of the composites. For some samples, a static magnetic field was applied during the polymerization process, resulting in anisotropic inclusion distributions. Our results show a significant difference in the thermal properties of the anisotropic samples, compared to the isotropic randomly distributed. We correlate some measures of the complexity of the inclusion structure with the observed thermal response through a multifractal analysis. In this way, we are able to describe, and at some extent predict, the behavior of the thermal diffusivity in terms of the lacunarity and other measures of the complexity of these samples Partial Financial Support by CONACyT México and VIEP-BUAP.

  16. Peptide Nanotube Reinforced Polymers: A System for Tunable, Composite Materials

    Science.gov (United States)

    2015-11-30

    Substrate PDLLA-QL4 composite fiber diameter ~ 0.5 µm AFM probe with glass colloid tip diameter ~ 40 µm Dan RubinRubin,#et#al."Biomacromol."(2013...Substrate Binding Quartz/ Glass binding Bioinformatics 2007, 23: 2816. SpyTag AHIVMVDAYKPTK 13 Protein Display General covalent capture/display of...GGTIWTGKGLGLGLGLGLGAW GPIILGVVGAGAVYAYMKSRDI ESAQSDEEVELRDALA 59 NP templating Magnetite NP templating JBC 2003, 278(10): 8745. Peter Nguyen 0# 0.2

  17. MusicFlow: an interactive music composition system

    Science.gov (United States)

    Tan, Sharon Yee Ping; Hu, Zhijia; Koh, Alan Yih Lun; Felicia; Zhao, Shengdong

    2010-07-01

    Music notation has evolved to the point in which music scores can be digitalized to give composers a different dimension of music composition. Traditional method of music notation using pen and paper requires much time and effort especially during reviewing and editing of hand written music scores. On the other hand of the spectrum, computerizing the entire music composition process can potentially reduce the workload; however, previous approaches in digitizing music notation suffer from the overwhelming functions and the lack of human touch. In this paper, we designed, implemented, and evaluated a multi-touch application called Musicflow, which allows for automatic transcription of composers' music into digital music scores through one's fingertips. To facilitate natural, efficient interaction, MusicFlow supports many multi-touch gestures such as music notation, editing and playing back for reviewing. In addition, Musicflow includes a collaborative teaching tool which further enhances music education by engaging both the teacher and students actively on a multi-touch table. Our initial evaluation indicates that MusicFlow is intuitive to use and effective for music composition.

  18. Model-based Compositional Design of Networked Control Systems

    Science.gov (United States)

    2013-12-01

    systems such as tele- robots for surgery , implanted heart monitors, nanoscale di- agnostic instruments, digital protheses and other medical devices, as...exploration, surgery , search and rescue missions, hazardous environment and other various military applications. An n-degrees of freedom robotic manipulator...lives. Examples of these systems include process control, automotive systems, networked robotics , medical systems, electrical power grids and

  19. Within day variation in fatty acid composition of milk from cows in an automatic milking system

    DEFF Research Database (Denmark)

    Larsen, Mette Krogh; Weisbjerg, Martin Riis; Kristensen, Camilla Bjerg

    2012-01-01

    Milk fatty acid composition is influenced by a range of conditions such as breed, feeding, and stage of lactation. Knowledge of milk fatty acid composition of individual cows would make it possible to sort milk at farm level according to certain fatty acid specifications. In the present study, 225...... milk samples were taken from 84 cows in a herd equipped with an automatic milking system. Milk fat content varied depending on yield and time since last milking, whereas the milk fatty acid composition did not vary significantly within cow. It was concluded that random milk samples may be used...... for analysis of fatty acid composition....

  20. Characterisation of electrical resistance for CMC Materials up to 1200 °C

    Science.gov (United States)

    Stäbler, T.; Böhrk, H.; Voggenreiter, H.

    2017-12-01

    Damage to thermal protection systems (TPS) during atmospheric re-entry is a severe safety issue, especially when considering re-usability of space transportation systems. There is a need for structural health monitoring systems and non-destructive inspection methods. However, damages are hard to detect. When ceramic matrix composites, in this case carbon fibre reinforced silicon carbide (C/C-SiC), are used as a TPS, the electrical properties of the present semiconductor material can be used for health monitoring, since the resistivity changes with damage, strain and temperature. In this work the electrical resistivity as a function of the material temperature is analysed eliminating effects of thermal electricity and the thermal coefficient of electrical resistance is determined. A sensor network is applied for locally and time resolved monitoring of the 300 mm x 120 mm x 3 mm panel shaped samples. Since the material is used for atmospheric re-entry it needs to be characterised for a wide range of temperatures, in this case as high as 1200 °C. Therefore, experiments in an inductively heated test bench were conducted. Firstly, a reference sample was used with thermocouples for characterising the temperature distribution across the sample surface. Secondly, electrical resistance under heat load was measured, time and spatially resolved. Results will be shown and discussed in terms of resistance dependence on temperature, thermal coefficient of electrical resistance, thermal electricity and electrical path orientation including an analysis on effective conducting cross section. Conversely, the thermal coefficient can also be used to determine the material temperature as a function of electrical resistance.

  1. CMH-17 Volume 5 Ceramic Matrix Composites

    Science.gov (United States)

    Andrulonis, Rachael; Kiser, J. Douglas; David, Kaia E.; Davies, Curtis; Ashforth, Cindy

    2017-01-01

    A wide range of issues must be addressed during the process of certifying CMC (ceramic matrix composite) components for use in commercial aircraft. The Composite Materials Handbook-17, Volume 5, Revision A on ceramic matrix composites has just been revised to help support FAA certification of CMCs for elevated temperature applications. The handbook supports the development and use of CMCs through publishing and maintaining proven, reliable engineering information and standards that have been thoroughly reviewed. Volume 5 contains detailed sections describing CMC materials processing, design analysis guidelines, testing procedures, and data analysis and acceptance. A review of the content of this latest revision will be presented along with a description of how CMH-17, Volume 5 could be used by the FAA (Federal Aviation Administration) and others in the future.

  2. Elrotherm shielding systems. New pioneering material composites; Elrotherm-Abschirmsysteme. Neue Zukunftsweisende Materialkompositionen

    Energy Technology Data Exchange (ETDEWEB)

    Zika-Beyerlein, B. [ElringKlinger (Germany). Geschaeftsbereich Abschirmtechnik

    2004-09-01

    Tightly packed engine compartments put special demands on thermal and acoustic shielding systems. With new material composites allowing for particularly thin-walled and light shielding parts, ElringKlinger is well equipped for the future. (orig.)

  3. Color-infrared composite of Landsat data for the Death Valley regional flow system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The raster-based, color-infrared composite was derived from Landsat Thematic Mapper imagery data acquired during June 1992 for the Death Valley regional flow system....

  4. On-orbit validation system for space structure composite actuators Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR project delivers an On-orbit Validation System (OVS) that provides performance and durability data for Macro Fiber Composite (MFC) active piezocomposite...

  5. Advanced Composite Bipolar Plate for Unitized Regenerative Fuel Cell/Electrolyzer Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of an advanced composite bipolar plate is proposed for a unitized regenerative fuel cell and electrolyzer system that operates on pure feed streams...

  6. Single Vacuum Bagging and Autoclave Curing System Influence on Physical and Mechanical Properties of Phenolic Composites

    Directory of Open Access Journals (Sweden)

    M.A. Mirzapour

    2010-12-01

    Full Text Available Industrial production of thermoset composite components involves the application of a vacuum bagging and autoclave pressure to minimize void percentage, usually to less than 5%. Phenolic resin systems generate water as a reaction byproduct via condensation reactions during curing at elevated temperatures. In this paper, vacuum bagging and simple manufactured autoclave curing systems are used for manufacturing of asbestos/phenolic composites and the effects of processing conditions on manufactured composites are investigated. The traditional single-vacuum-bag process is unable to manage the volatiles effectively, resulting in inferior laminates having voids. The autoclave process cure cycle (temperature/pressure profiles for the selected composite system is designed to emit volatiles during curing reactions effectively and produce composites with low void contents and excellent mechanical properties. Laminate consolidation quality is characterized by optical photomicrography for the cross-sections and measurements of void content and mechanical properties. The void content of phenolic composites as opposed to other composites increases as pressure increases up to 3 bar and it is then decreased beyond it. A product of 124% lower void content, 13% higher density, 24% higher flexural strength and 27% higher flexural modulus can be fabricated in composites obtainedby autoclave processing.

  7. Temperature and pH responsive behaviours of CMC/AAc hydrogels prepared by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    El-Naggar, Abdel Wahab M. [Department of Radiation Chemistry, National Center for Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo (Egypt)]. E-mail: ab_nagga@yahoo.com; Alla, Safaa G. Abd [Department of Radiation Chemistry, National Center for Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo (Egypt); Said, Hossam M. [Department of Radiation Chemistry, National Center for Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo (Egypt)

    2006-01-10

    The temperature and pH-responsive characters of hydrogels prepared from aqueous solutions containing 4.2 and 25% (w/v) carboxymethyl cellulose (CMC) and acrylic acid (AAc), respectively under the effect of accelerated electrons was investigated. Even though the initial content of hydrogels solution is constant, the swelling in water and responsive characters were greatly dependent on electron beam irradiation dose. In this regard, the percentage swelling in water of the hydrogel prepared at 50 kGy is relatively higher than that prepared at 80 kGy. However, both hydrogels displayed super water absorbing behaviour at room temperature in the range of {approx}3500-4000%. The hydrogels exhibit a relatively low tendency to swell in methanol with respect to water, in which the overall swelling in water is {approx}12 times that in methanol. The deswelling of the hydrogels at 40 deg. C in water from the equilibrium swelling state at 25 deg. C showed a lower rate than the swelling process. The results showed that the CMC/AAc hydrogel prepared at 50 kGy has a temperature-response character within the temperature range 25 + 15 deg. C at any time of swelling, while the hydrogel prepared at 80 kGy, does not show this character within this range of temperature. While the swelling of CMC/AAc hydrogel prepared at 50 kGy was found to substantially increase with increasing pH values from 3 to 10, the hydrogel prepared at 80 kGy was found to display pH responsive character below and above 7.

  8. Canonical Measure of Correlation (CMC) and Canonical Measure of Distance (CMD) between sets of data Part 2. Variable reduction.

    Science.gov (United States)

    Consonni, V; Ballabio, D; Manganaro, A; Mauri, A; Todeschini, R

    2009-08-19

    This paper proposes a new method for determining the subset of variables that reproduce as well as possible the main structural features of the complete data set. This method can be useful for pre-treatment of large data sets since it allows discarding variables that contain redundant information. Reducing the number of variables often allows one to better investigate data structure and obtain more stable results from multivariate modelling methods. The novel method is based on the recently proposed canonical measure of correlation (CMC index) between two sets of variables [R. Todeschini, V. Consonni, A. Manganaro, D. Ballabio, A. Mauri, Canonical Measure of Correlation (CMC) and Canonical Measure of Distance (CMD) between sets of data. Part 1. Theory and simple chemometric applications, Anal. Chim. Acta submitted for publication (2009)]. Following a stepwise procedure (backward elimination), each variable in turn is compared to all the other variables and the most correlated is definitively discarded. Finally, a key subset of variables being as orthogonal as possible are selected. The performance was evaluated on both simulated and real data sets. The effectiveness of the novel method is discussed by comparison with results of other well known methods for variable reduction, such as Jolliffe techniques, McCabe criteria, Krzanowski approach and its modification based on genetic algorithms, loadings of the first principal component, Key Set Factor Analysis (KSFA), Variable Inflation Factor (VIF), pairwise correlation approach, and K correlation analysis (KIF). The obtained results are consistent with those of the other considered methods; moreover, the advantage of the proposed CMC method is that calculation is very quick and can be easily implemented in any software application.

  9. Canonical Measure of Correlation (CMC) and Canonical Measure of Distance (CMD) between sets of data. Part 3. Variable selection in classification.

    Science.gov (United States)

    Ballabio, Davide; Consonni, Viviana; Mauri, Andrea; Todeschini, Roberto

    2010-01-11

    In multivariate regression and classification issues variable selection is an important procedure used to select an optimal subset of variables with the aim of producing more parsimonious and eventually more predictive models. Variable selection is often necessary when dealing with methodologies that produce thousands of variables, such as Quantitative Structure-Activity Relationships (QSARs) and highly dimensional analytical procedures. In this paper a novel method for variable selection for classification purposes is introduced. This method exploits the recently proposed Canonical Measure of Correlation between two sets of variables (CMC index). The CMC index is in this case calculated for two specific sets of variables, the former being comprised of the independent variables and the latter of the unfolded class matrix. The CMC values, calculated by considering one variable at a time, can be sorted and a ranking of the variables on the basis of their class discrimination capabilities results. Alternatively, CMC index can be calculated for all the possible combinations of variables and the variable subset with the maximal CMC can be selected, but this procedure is computationally more demanding and classification performance of the selected subset is not always the best one. The effectiveness of the CMC index in selecting variables with discriminative ability was compared with that of other well-known strategies for variable selection, such as the Wilks' Lambda, the VIP index based on the Partial Least Squares-Discriminant Analysis, and the selection provided by classification trees. A variable Forward Selection based on the CMC index was finally used in conjunction of Linear Discriminant Analysis. This approach was tested on several chemical data sets. Obtained results were encouraging.

  10. Compositional abstractions for long-run properties of stochastic systems

    DEFF Research Database (Denmark)

    Smith, Michael James Andrew

    2011-01-01

    its underlying Markov chain. However, this also leads to state space explosion problems as the number of components in the model increases, which severely limits the size of models we can analyse. Because of this, we look for abstraction techniques that allow us to analyse a smaller model that safely...... be reduced in size. Importantly, we do this compositionally, so that we bound each component of the model separately, and compose these to obtain a bound for the entire model. We present an algorithm for this, based on extending the algorithm by Fourneau et al. to deal with partially-ordered state spaces...

  11. The diversity of planetary system from formation/composition population synthesis models

    Science.gov (United States)

    Alibert, Yann; thiabaud, amaury; marboeuf, ulysses; swoboda, david; benz, willy; mezger, klaus; leya, ingo

    2015-12-01

    Extrasolar planetary systems show an extreme diversity in mass and orbital architecture. Explaining this diversity is one of the key challenges for theoretical models and requires understanding the formation, composition and evolution of planetary systems from the stage of the protoplanetary disk up to the full mature planetary system. Such an effort needs the development of end-to-end, necessarily simplified, formation models used in a population synthesis approach. We present in this contribution such planetary system formation and composition models. Our planetary system formation models include the following effects: planetary growth by capture of solids and gas, protoplanetary disk structure and evolution, planet-planet and planet-disk interactions. In addition, we compute the composition of the solids and gas in the protoplanetary disk and their evolution with time. The formation and composition models allow therefore the determination of the composition of planets in terms of refractory elements (Mg, Si, Fe, etc…) as well as volatile compounds (water, CO2, CO, NH3, etc…), in a way that is self-consistent with the formation process of the different members of the planetary system. We will show the results of these formation/composition models, and will compare the diversity of observed and synthetic planetary systems. Considering the solar system, we will show how different formation scenarios translate into different planetary compositions. Finally, we will demonstrate how the simultaneous determination of mass and radius of a statistical number of warm to cold earth to neptune mass bodies at different ages can be used to constrain the composition (in particular the volatile content) of planets, and how the same observations (mass, radius, period) can be used in order to select planets that are best suited for follow-up habitability studies.

  12. Portable combined thermography/shearography NDT system for inspecting large composite structures

    Science.gov (United States)

    Burleigh, Douglas D.

    2002-03-01

    The use of a combination TNDT/SNDT (Thermographic nondestructive testing/ Shearographic nondestructive testing) system for the inspection of large composite structures is discussed. While each of the techniques may find defects on a particular composite structure, each may show types or sizes of defects that the other does not. The two methods complement one another well. A combination TNDT/SNDT system would provide the benefits of both techniques.

  13. Long-Acting Composite Systems Based on Powdered Medicinal Plants and Nanosilica

    Directory of Open Access Journals (Sweden)

    Turov, V.V.

    2017-03-01

    Full Text Available The state of water in the powdered plant materials (calendula, hibiscus and their composite systems with A-300 nanosilicas having different bulk density has been studied by low-temperature 1H NMR spectroscopy method. The change in bulk density has been found to significantly affect the radius of inner cavities in fibrillar space of plant components. The composite systems based on wetting-drying compaction of nanosilica and plant powder have been showed to form a mix with high interaction energy of heterogeneous particles. This results in the effective retention of plant bioactive complex by composite, which enables the development of long-acting herbal drugs.

  14. Architectures for High-Performance Ceramic Composites Being Improved

    Science.gov (United States)

    Yun, Hee Mann; DiCarlo, James A.

    2002-01-01

    A major thrust of the Ultra-Efficient Engine Technology (UEET) Program at the NASA Glenn Research Center is to develop advanced hot-section engine components using SiC/SiC ceramic matrix composites (CMC's) with thermostructural capability to 2400 F (1315 C). In previous studies, UEET determined that the higher the ultimate tensile strength (UTS) of the as-fabricated CMC, the greater its structural performance at 2400 F. Thus efforts have been ongoing within UEET to understand and develop fiber architecture approaches that can improve the UTS of SiC/SiC CMC's. Under UEET, SiC/SiC test panels and demonstration engine components are currently produced by the multi-ply layup of two-dimensional fabric pieces. The fabric is typically formed of multifilament tows containing high-performance Sylramic (Dow Corning) SiC fiber that is woven into two-dimensional five-harness satin fabric with 20 ends per inch in the 0 degree and 90 degree directions. In some cases, fabric pieces containing woven Sylramic fiber tows are thermally treated at NASA to form Sylramic-iBN fibers that contain a very thin in-situ-grown boron nitride layer on their surfaces. The final SiC/SiC panels and components are fabricated at the CMC vendor by compressing the fabric pieces in tools and then depositing a thin BN interphase coating on the fibers by chemical vapor deposition. The last step at the vendor is to infiltrate the BN-coated fiber architecture with SiC and silicon matrix constituents to form a dense product. Because the as-produced Sylramic fiber tows are sized with a thin polymer coating to facilitate handling and weaving, the individual fibers within the tows and fabric are in close contact with each other. This contact is further increased during fabric compression. One important recent finding is that increasing Sylramic fiber tow width in a fabric increases the UTS of the final SiC/SiC CMC. This effect is presumably related to minimizing fiber/fiber contact, which can be detrimental to

  15. General Approach for Composite Thermoelectric Systems with Thermal Coupling: The Case of a Dual Thermoelectric Cooler

    Directory of Open Access Journals (Sweden)

    Cuautli Yanehowi Flores-Niño

    2015-06-01

    Full Text Available In this work, we show a general approach for inhomogeneous composite thermoelectric systems, and as an illustrative case, we consider a dual thermoelectric cooler. This composite cooler consists of two thermoelectric modules (TEMs connected thermally in parallel and electrically in series. Each TEM has different thermoelectric (TE properties, namely thermal conductance, electrical resistance and the Seebeck coefficient. The system is coupled by thermal conductances to heat reservoirs. The proposed approach consists of derivation of the dimensionless thermoelectric properties for the whole system. Thus, we obtain an equivalent figure of merit whose impact and meaning is discussed. We make use of dimensionless equations to study the impact of the thermal conductance matching on the cooling capacity and the coefficient of the performance of the system. The equivalent thermoelectric properties derived with our formalism include the external conductances and all intrinsic thermoelectric properties of each component of the system. Our proposed approach permits us changing the thermoelectric parameters of the TEMs and the working conditions of the composite system. Furthermore, our analysis shows the effect of the number of thermocouples on the system. These considerations are very useful for the design of thermoelectric composite systems. We reproduce the qualitative behavior of a commercial composite TEM connected electrically in series.

  16. Infra-red and vibration tests of hybrid ablative/ceramic matrix technological breadboards for earth re-entry thermal protection systems

    Science.gov (United States)

    Barcena, Jorge; Garmendia, Iñaki; Triantou, Kostoula; Mergia, Konstatina; Perez, Beatriz; Florez, Sonia; Pinaud, Gregory; Bouilly, Jean-Marc; Fischer, Wolfgang P. P.

    2017-05-01

    A new thermal protection system for atmospheric earth re-entry is proposed. This concept combines the advantages of both reusable and ablative materials to establish a new hybrid concept with advanced capabilities. The solution consists of the design and the integration of a dual shield resulting on the overlapping of an external thin ablative layer with a Ceramic Matrix Composite (CMC) thermo-structural core. This low density ablative material covers the relatively small heat peak encountered during re-entry the CMC is not able to bear. On the other hand the big advantage of the CMC based TPS is of great benefit which can deal with the high integral heat for the bigger time period of the re-entry. To verify the solution a whole testing plan is envisaged, which as part of it includes thermal shock test by infra-red heating (heating flux up to 1 MW/m2) and vibration test under launcher conditions (Volna and Ariane 5). Sub-scale tile samples (100×100 mm2) representative of the whole system (dual ablator/ceramic layers, insulation, stand-offs) are specifically designed, assembled and tested (including the integration of thermocouples). Both the thermal and the vibration test are analysed numerically by simulation tools using Finite Element Models. The experimental results are in good agreement with the expected calculated parameters and moreover the solution is qualified according to the specified requirements.

  17. Composite Overwrapped Pressure Vessels (COPV) Monitoring System Using Fiber Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Intelligent Fiber Optic Systems Corporation (IFOS) proposes, in this Phase 1 SBIR project, to demonstrate the feasibility of innovations based on an...

  18. Durability of a low shrinkage TEGDMA/HEMA-free resin composite system in Class II restorations

    DEFF Research Database (Denmark)

    van Dijken, Jan WV; Pallesen, Ulla

    2017-01-01

    Objective: The objective of this randomized controlled prospective trial was to evaluate the durability of a low shrinkage and TEGDMA/HEMA-free resin composite system in posterior restorations in a 6-year follow up. Material and methods: 139 Class II restorations were placed in 67 patients...... with a mean age of 53 years (range 29-82). Each participant received at random two, as similar as possible, Class II restorations. In the first cavity of each pair the TEGDMA/HEMA-free resin composite system was placed with its 3-step etch-and-rinse adhesive (cmf-els). In the second cavity a 1-step HEMA...... for failure were fracture followed by recurrent caries. Most fractures and all caries lesions were found in high risk participants. Significance: The tested Class II resin composite restorations performed with the new TEGDMA/HEMA-free low shrinkage resin composite system showed good durability over six years....

  19. Giant Planets of Our Solar System Atmospheres, Composition, and Structure

    CERN Document Server

    Irwin, Patrick G. J

    2009-01-01

    This book reviews the current state of knowledge of the atmospheres of the giant gaseous planets: Jupiter, Saturn, Uranus, and Neptune. The current theories of their formation are reviewed and their recently observed temperature, composition and cloud structures are contrasted and compared with simple thermodynamic, radiative transfer and dynamical models. The instruments and techniques that have been used to remotely measure their atmospheric properties are also reviewed, and the likely development of outer planet observations over the next two decades is outlined. This second edition has been extensively updated following the Cassini mission results for Jupiter/Saturn and the newest ground-based measurements for Uranus/Neptune as well as on the latest development in the theories on planet formation.

  20. An enhanced Whipple Bumper system - Impact resistance of composite materials

    Science.gov (United States)

    Zwiener, J.; Mount, A.; Herren, K.; Nettles, A.; Semmel, C.; Sims, J.

    1992-01-01

    For long-duration space flights where human occupation is expected, micrometeroid and debris shields are necessary to prevent puncture of the pressure vessels. Current 'Whipple Bumper' designs range from single thin sheets of aluminum to complicated structures of many energy absorbing layers. This paper details the results of an experimental program tao determine the increased protection afforded by intermediate bumpers made of composite material structures. Various configurations of honeycomb support structures sandwiched between layers of materials such as Kevlar, Spectra, aluminum, and others are inserted between the bumper and pressure shell. The areal densities of each new material structure are maintained constant so that the results compare directly with single-sheet aluminum intermediate bumpers.

  1. Triple oxygen isotope composition of the Campi Flegrei magma systems

    Science.gov (United States)

    Iovine, Raffaella Silvia; Wörner, Gerhard; Pack, Andreas; Sengupta, Sukanya; Carmine Mazzeo, Fabio; Arienzo, Ilenia; D'Antonio, Massimo

    2017-04-01

    Sr-O isotope relationships in igneous rocks are a powerful tool to distinguish magma sources and quantify assimilation processes in magmatic rocks. Isotopic (87Sr/86Sr and 18O/16O-17O/16O) data have been acquired on whole rocks and separated minerals (feldspar, Fe-cpx, Mg-cpx, olivine phenocrysts) from pyroclastic products of the Campi Flegrei volcanic complex (Gulf of Naples, Southern Italy). Oxygen isotope ratios were measured by infrared laser fluorination using a Thermo MAT253 gas source isotope ratio mass spectrometer in dual inlet mode, on ˜2 mg of hand-picked phenocrysts. Variations in triple oxygen isotope ratios (17O/16O, 18O/16O) are expressed as the δ notation relative to VSMOW. Sr isotopic compositions were determined by thermal ionization mass spectrometry after standard cation-exchange methods on separated hand-picked phenocrysts (˜300 mg), and on whole rocks, in case of insufficient sample size to separate crystals. Sr-isotopes in Campi Flegrei minerals range from 0.707305 to 0.707605 and δ18O varies from 6.5 to 8.3‰ . Recalculated δ18Omelt values accordingly show a large range between 7.2 and 8.6‰ . Our data, compared with published δ18O-isotope data from other Italian volcanic centers (Alban Hills, Mts. Ernici, Ischia, Mt. Vesuvius, Aeolian Islands, Tuscany and Sardinia) and from subduction zones worldwide (Kamchatka, Lesser Antilles, Indonesia and Central Andean ignimbrites), show compositions that are very different from typical mantle values. Distinct trends and sources are recognized in our compilation from global data: (1) serpentinized mantle (Kamchatka), (2) sediment-enrichment in the mantle source (Indonesia, Lesser Antilles, Eolian arc), (3) assimilation of old radiogenic continental crust affecting magmas derived from sediment-modified mantle sources (Tuscany, Sardinia), (4) assimilation of lower crustal lithologies (Central Andes, Alban Hills, Mts. Ernici, Ischia). Sr-O-isotope values of Campi Flegrei and Vesuvius magmas

  2. Film Cooled Recession of SiC/SiC Ceramic Matrix Composites: Test Development, CFD Modeling and Experimental Observations

    Science.gov (United States)

    Zhu, Dongming; Sakowski, Barbara A.; Fisher, Caleb

    2014-01-01

    SiCSiC ceramic matrix composites (CMCs) systems will play a crucial role in next generation turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures, reduce engine weight and cooling requirements. However, the environmental stability of Si-based ceramics in high pressure, high velocity turbine engine combustion environment is of major concern. The water vapor containing combustion gas leads to accelerated oxidation and corrosion of the SiC based ceramics due to the water vapor reactions with silica (SiO2) scales forming non-protective volatile hydroxide species, resulting in recession of the ceramic components. Although environmental barrier coatings are being developed to help protect the CMC components, there is a need to better understand the fundamental recession behavior of in more realistic cooled engine component environments.In this paper, we describe a comprehensive film cooled high pressure burner rig based testing approach, by using standardized film cooled SiCSiC disc test specimen configurations. The SiCSiC specimens were designed for implementing the burner rig testing in turbine engine relevant combustion environments, obtaining generic film cooled recession rate data under the combustion water vapor conditions, and helping developing the Computational Fluid Dynamics (CFD) film cooled models and performing model validation. Factors affecting the film cooled recession such as temperature, water vapor concentration, combustion gas velocity, and pressure are particularly investigated and modeled, and compared with impingement cooling only recession data in similar combustion flow environments. The experimental and modeling work will help predict the SiCSiC CMC recession behavior, and developing durable CMC systems in complex turbine engine operating conditions.

  3. Composite Petroleum System and Advantageous Exploration Targets in the Kongquehe Area of Tarim Basin

    Science.gov (United States)

    Tang, Dazhen; Xing, Weixin; Lin, Wenji; Kong, Fanjun; Li, Danmei; Xu, Hao; Tao, Shu; Gao, Guanfeng

    Guided by the description methods and evaluation routine for composite petroleum system in superimposed basins, the composite characteristics of the petroleum systems in the Kongquehe area of the Tarim basin was studied and the geological evolution processes of hydrocarbon from source to trap was revealed. The petroleum systems in the Kongquehe area, mainly through fault composite linkage combined with unconformity surface composite linkage, constitute the Cambrian € (!)-Lower Ordovician O 1 (!)-Carboniferous C (*)-Triassic T (*)-Jurassic J (*) + Cambrian € (!)-Lower Ordovician O 1 (*)-Silurian S (*)-Devonian D (*)-Jurassic J (*) modified composite petroleum systems (*). There are three critical periods for composite petroleum system, such as the end of Devonian for forming tectonic framework and paleoreservoir, the end of Jurassic and Cretaceous for hydrocarbon transformation, redistribution, and adjustment. The research area may be classified into three types — destroyed dissipation zone, transformed adjustment zone, and deeply-buried preservation zone, amongst which the latter two zones are favorable for hydrocarbon accumulation. Especially, the Upper Paleozoic and Mesozoic faulted anticline traps of the Longkou anticline and the Weimake-Kaiping anticline and the residual Lower Paleozoic fault paleo-anticline traps in the transformed adjustment zone are the best prospecting targets.

  4. Effect of finishing system on carcass characteristics and composition ...

    African Journals Online (AJOL)

    Martina Muller

    2013-09-18

    Sep 18, 2013 ... A study was conducted to evaluate the influence of feeding systems on carcass characteristics and ... conducted to link animal breed and production system to carcass quality from Mubende goats. ..... characteristics of intact male Mubende goats fed elephant grass (Pennisetum purpureum) ad libitum in.

  5. Enhancing SOEC system lifetime by controlling inlet gas composition

    DEFF Research Database (Denmark)

    2015-01-01

    In a method for enhancing the lifetime of a solid oxide electrolysis cell system by counteracting nitridation of the threads of the in-line electrical heaters of the system, the start-up, shut-down and trip operations are done in a humidified nitrogen atmosphere on the fuel side to achieve a dew...

  6. Biomimetic remineralization of demineralized dentine using scaffold of CMC/ACP nanocomplexes in an in vitro tooth model of deep caries.

    Directory of Open Access Journals (Sweden)

    Zhen Chen

    Full Text Available Currently, it is still a tough task for dentists to remineralize dentine in deep caries. The aim of this study was to remineralize demineralized dentine in a tooth model of deep caries using nanocomplexes of carboxymethyl chitosan/amorphous calcium phosphate (CMC/ACP based on mimicking the stabilizing effect of dentine matrix protein 1 (DMP1 on ACP in the biomineralization of dentine. The experimental results indicate that CMC can stabilize ACP to form nanocomplexes of CMC/ACP, which is able to be processed into scaffolds by lyophilization. In the single-layer collagen model, ACP nanoparticles are released from scaffolds of CMC/ACP nanocomplexes dissolved and then infiltrate into collagen fibrils via the gap zones (40 nm to accomplish intrafibrillar mineralization of collagen. With this method, the completely demineralized dentine was partially remineralized in the tooth mode. This is a bottom-up remineralizing strategy based on non-classical crystallization theory. Since nanocomplexes of CMC/ACP show a promising effect of remineralization on demineralized dentine via biomimetic strategy, thereby preserving dentinal tissue to the maximum extent possible, it would be a potential indirect pulp capping (IPC material for the management of deep caries during vital pulp therapy based on the concept of minimally invasive dentistry (MID.

  7. Biomimetic Remineralization of Demineralized Dentine Using Scaffold of CMC/ACP Nanocomplexes in an In Vitro Tooth Model of Deep Caries

    Science.gov (United States)

    Chen, Zhen; Cao, Shansong; Wang, Haorong; Li, Yanqiu; Kishen, Anil; Deng, Xuliang; Yang, Xiaoping; Wang, Yinghui; Cong, Changhong; Wang, Huajun; Zhang, Xu

    2015-01-01

    Currently, it is still a tough task for dentists to remineralize dentine in deep caries. The aim of this study was to remineralize demineralized dentine in a tooth model of deep caries using nanocomplexes of carboxymethyl chitosan/amorphous calcium phosphate (CMC/ACP) based on mimicking the stabilizing effect of dentine matrix protein 1 (DMP1) on ACP in the biomineralization of dentine. The experimental results indicate that CMC can stabilize ACP to form nanocomplexes of CMC/ACP, which is able to be processed into scaffolds by lyophilization. In the single-layer collagen model, ACP nanoparticles are released from scaffolds of CMC/ACP nanocomplexes dissolved and then infiltrate into collagen fibrils via the gap zones (40 nm) to accomplish intrafibrillar mineralization of collagen. With this method, the completely demineralized dentine was partially remineralized in the tooth mode. This is a bottom-up remineralizing strategy based on non-classical crystallization theory. Since nanocomplexes of CMC/ACP show a promising effect of remineralization on demineralized dentine via biomimetic strategy, thereby preserving dentinal tissue to the maximum extent possible, it would be a potential indirect pulp capping (IPC) material for the management of deep caries during vital pulp therapy based on the concept of minimally invasive dentistry (MID). PMID:25587986

  8. NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 38: Computer Mediated Communication (CMC) and the communication of technical information in aerospace

    Science.gov (United States)

    Murphy, Daniel J.; Pinelli, Thomas E.

    1994-01-01

    This paper discusses the use of computers as a medium for communication (CMC) used by aerospace engineers and scientists to obtain and/or provide technical information related to research and development activities. The data were obtained from a questionnaire survey that yielded 1006 mail responses. In addition to communication media, the research also investigates degrees of task uncertainty, environmental complexity, and other relevant variables that can affect aerospace workers' information-seeking strategies. While findings indicate that many individuals report CMC is an important function in their communication patterns, the research indicates that CMC is used less often and deemed less valuable than other more conventional media, such as paper documents, group meetings, telephone and face-to-face conversations. Fewer than one third of the individuals in the survey account for nearly eighty percent of the reported CMC use, and another twenty percent indicate they do not use the medium at all, its availability notwithstanding. These preliminary findings suggest that CMC is not as pervasive a communication medium among aerospace workers as the researcher expect a priori. The reasons underlying the reported media use are not yet fully known, and this suggests that continuing research in this area may be valuable.

  9. Designing and Testing Composite Energy Storage Systems for Regulating the Outputs of Linear Wave Energy Converters

    Directory of Open Access Journals (Sweden)

    Zanxiang Nie

    2017-01-01

    Full Text Available Linear wave energy converters generate intrinsically intermittent power with variable frequency and amplitude. A composite energy storage system consisting of batteries and super capacitors has been developed and controlled by buck-boost converters. The purpose of the composite energy storage system is to handle the fluctuations and intermittent characteristics of the renewable source, and hence provide a steady output power. Linear wave energy converters working in conjunction with a system composed of various energy storage devices, is considered as a microsystem, which can function in a stand-alone or a grid connected mode. Simulation results have shown that by applying a boost H-bridge and a composite energy storage system more power could be extracted from linear wave energy converters. Simulation results have shown that the super capacitors charge and discharge often to handle the frequent power fluctuations, and the batteries charge and discharge slowly for handling the intermittent power of wave energy converters. Hardware systems have been constructed to control the linear wave energy converter and the composite energy storage system. The performance of the composite energy storage system has been verified in experiments by using electronics-based wave energy emulators.

  10. An Information System of Human Body Composition Based on Android Client

    Directory of Open Access Journals (Sweden)

    Bing Liu

    2014-12-01

    Full Text Available This paper proposes an information system of human body composition based on Android client. The system consists of the Android client, the measurement unit, the Database Server, the FTP Server, the Web Server and portable storage devices. It is able to collect, restore, synchronize, and batch import and export user profile information and human body composition information. The merits of the system are that the development cycle is shortened, the cost and energy consumption of equipment are reduced, and the portability and mobility are enhanced. The system has also optimized the communication of human body composition measurement. As a result, the client and the measurement unit are robust and capable of addressing the fault and solving deficiencies in the communication process. With a more reliable system, accurate transmission of data can be guaranteed.

  11. Oxidation Resistant CMC Materials Technology for Lightweight and Environmentally Durable Propulsion Components Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Foster-Miller will demonstrate a novel processing method to develop environmentally resistant C/SiC composites for turbomachinery. The need to reduce the weight,...

  12. Extreme Environment Damage Index and Accumulation Model for CMC Laminate Fatigue Life Prediction Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Materials Research & Design (MR&D) is proposing in the SBIR Phase II an effort to develop a tool for predicting the fatigue life of C/SiC composite...

  13. Oxidation Resistant CMC Materials Technology for Lightweight and Environmentally Durable Propulsion Components Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Surmet will demonstrate a novel processing method to develop environmentally resistant C/SiC composites for turbomachinery. The need to reduce the weight, size, and...

  14. Removal of Cu{sup 2+} and Pb{sup 2+} ions using CMC based thermoresponsive nanocomposite hydrogel

    Energy Technology Data Exchange (ETDEWEB)

    Oezkahraman, Bengi [Faculty of Engineering, Chemical Engineering Department, Hitit University, Corum (Turkey); Acar, Isil; Emik, Serkan [Faculty of Engineering, Chemical Engineering Department, Istanbul University, Avcilar-Istanbul (Turkey)

    2011-07-15

    In this study, carboxymethylcellulose (CMC) based thermoresponsive nanocomposite hydrogel was synthesized for the removal of Cu{sup 2+} and Pb{sup 2+} ions from aqueous solutions. To prepare nanocomposite hydrogel, graft copolymerization of N-isopropyl acrylamide (NIPAm) and acrylic acid (AA) onto CMC was carried out in Na-montmorillonite (MMT)/water suspension media and ammonium persulfate (APS) used as initiator. The chemical structures of hydrogels were characterized by Fourier transform infrared (FT-IR) and X-ray diffraction spectroscopy (XRD). Lower critical solution temperature (LCST), pH responsivity, swelling, and deswelling properties of the hydrogels were also examined. In addition competitive and non-competitive removal of Cu{sup 2+} and Pb{sup 2+} studies were carried out. According to heavy metal sorption studies results, removal capacities of nanocomposite hydrogel for both metal ions were found to be higher than those of pure hydrogel. The analyzed adsorption data showed that the adsorption process of Cu{sup 2+} and Pb{sup 2+} could be explained by pseudo-second order kinetic model. Moreover, according to competitive sorption studies, it is found to be that both hydrogels are more selective to Cu{sup 2+} ion rather than Pb{sup 2+}. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Collaboration between HPMC and NaCMC in order to Reach the Polymer Critical Point in Theophylline Hydrophilic Matrices

    Directory of Open Access Journals (Sweden)

    L. Contreras

    2012-01-01

    Full Text Available Percolation theory has been applied in order to study the existence of critical points as well as the possibility to find a “combined percolation threshold” for ternary hydrophilic matrices prepared with HPMC, NaCMC, and theophylline. For this purpose, different batches of ternary as well as binary hydrophilic matrices have been prepared. Critical points have been found for binary hydrophilic matrices between 21.5 and 31.3% (v/v of HPMC and between 39 and 54% (v/v of NaCMC, respectively. In a previous work carried out with the same polymers but a much more soluble drug (KCl, it was demonstrated the existence of a partial collaboration between the polymers in order to establish the gel layer. In this work, it has been observed for the first time the need of a minimum concentration of one of the matrix-forming polymer (between 10 and 20% v/v, approximately for establishing an effective collaboration.

  16. Collaboration between HPMC and NaCMC in order to Reach the Polymer Critical Point in Theophylline Hydrophilic Matrices

    Science.gov (United States)

    Contreras, L.; Melgoza, L. M.; Aguilar-de-Leyva, A.; Caraballo, I.

    2012-01-01

    Percolation theory has been applied in order to study the existence of critical points as well as the possibility to find a “combined percolation threshold” for ternary hydrophilic matrices prepared with HPMC, NaCMC, and theophylline. For this purpose, different batches of ternary as well as binary hydrophilic matrices have been prepared. Critical points have been found for binary hydrophilic matrices between 21.5 and 31.3% (v/v) of HPMC and between 39 and 54% (v/v) of NaCMC, respectively. In a previous work carried out with the same polymers but a much more soluble drug (KCl), it was demonstrated the existence of a partial collaboration between the polymers in order to establish the gel layer. In this work, it has been observed for the first time the need of a minimum concentration of one of the matrix-forming polymer (between 10 and 20% v/v, approximately) for establishing an effective collaboration. PMID:22919292

  17. Novel Composite Membrane for Space Life Supporting System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Space life-supporting systems require effective removal of metabolic CO2 from the cabin atmosphere with minimal loss of O2. Conventional techniques, using either...

  18. Gas composition modeling in a reformed Methanol Fuel Cell system using adaptive Neuro-Fuzzy Inference Systems

    DEFF Research Database (Denmark)

    Justesen, Kristian Kjær; Andreasen, Søren Juhl; Shaker, Hamid Reza

    2013-01-01

    This work presents a method for modeling the gas composition in a Reformed Methanol Fuel Cell system. The method is based on Adaptive Neuro-Fuzzy-Inference-Systems which are trained on experimental data. The developed models are of the H2, CO2, CO and CH3OH mass flows of the reformed gas. The ANFIS...

  19. A nanometallic nickel-coated, glass-fibre-based structural health monitoring system for polymer composites

    Science.gov (United States)

    Balaji, R.; Sasikumar, M.

    2017-09-01

    Glass-fibre-reinforced polymer matrix composites are widely used in various industries because of their unique high strength to weight ratio. Unlike metals, strain-induced and damage states of composites are complicated to predict under real-time loading due to their anisotropic nature. With that focus, a piezoresistive nanomaterial-based structural health monitoring system for laminated polymer composites is proposed to measure the strain induced in the composite under real-time loading. Nanometallic nickel-coated glass fibres are embedded into the polymer composites to monitor the strain and damage induced in them. The nanometallic nickel is coated over the glass fibre by a dip coating technique using epoxy as the binding agent. A microcontroller-based electrical resistance measurement system is used to measure the piezoresistive variation in the coated glass fibre under real-time loading. Using the piezoresistance variation of the embedded nanometallic nickel-coated glass fibre, the real-time strain and damage induced in the composite can be correlated. The piezoresistive response of the coated glass fibre is descibed in two phases, the deformation phase and the failure phase, which clearly show the various states of strain and damage induced in the composites.

  20. QuaBingo: A Prediction System for Protein Quaternary Structure Attributes Using Block Composition

    Directory of Open Access Journals (Sweden)

    Chi-Hua Tung

    2016-01-01

    Full Text Available Background. Quaternary structures of proteins are closely relevant to gene regulation, signal transduction, and many other biological functions of proteins. In the current study, a new method based on protein-conserved motif composition in block format for feature extraction is proposed, which is termed block composition. Results. The protein quaternary assembly states prediction system which combines blocks with functional domain composition, called QuaBingo, is constructed by three layers of classifiers that can categorize quaternary structural attributes of monomer, homooligomer, and heterooligomer. The building of the first layer classifier uses support vector machines (SVM based on blocks and functional domains of proteins, and the second layer SVM was utilized to process the outputs of the first layer. Finally, the result is determined by the Random Forest of the third layer. We compared the effectiveness of the combination of block composition, functional domain composition, and pseudoamino acid composition of the model. In the 11 kinds of functional protein families, QuaBingo is 23% of Matthews Correlation Coefficient (MCC higher than the existing prediction system. The results also revealed the biological characterization of the top five block compositions. Conclusions. QuaBingo provides better predictive ability for predicting the quaternary structural attributes of proteins.

  1. Surface plasmon polaritons in a composite system of porous silicon and gold

    Energy Technology Data Exchange (ETDEWEB)

    Vainshtein, J. S.; Goryachev, D. N.; Ken, O. S., E-mail: olja.ken@mail.ioffe.ru; Sreseli, O. M. [Ioffe Institute (Russian Federation)

    2015-04-15

    A composite system of silicon quantum dots and gold particles with properties periodically changing along the surface (i.e., a system exhibiting the properties of a diffraction grating) is obtained by a one-step metal-assisted chemical etching. The spectral and angular dependences of the photoresponse for the composite system on single-crystal silicon are studied. The photoresponse peaks were observed, which behavior (the dependence on the parameters of the diffraction grating, wavelength and incidence angles of light) is attributed to the excitation of plasmon-polariton modes at the surface of the composite system with the diffraction grating. At the same time, the obtained values of the wave vectors for these modes are smaller than those calculated for plasmon polaritons excited at the interface between air and metal (gold) diffraction grating.

  2. Health and usage monitoring system for the small aircraft composite structure

    Science.gov (United States)

    Růžička, Milan; Dvořák, Milan; Schmidová, Nikola; Šašek, Ladislav; Štěpánek, Martin

    2017-07-01

    This paper is focused on the design of the health and usage monitoring system (HUMS) of the composite ultra-light aircrafts. A multichannel measuring system was developed and installed for recording of the long-term operational measurements of the UL airplane. Many fiber Bragg grating sensors were implemented into the composite aircraft structure, mainly in the glue joints. More than ten other analog functions and signals of the aircraft is monitored and can be correlated together. Changing of the FBG sensors responses in monitored places and their correlations, comparing with the calibration and recalibration procedures during a monitored life may indicate damage (eg. in bonded joints) and complements the HUMS system.

  3. Nanomagnetite-Zeolite Composites in the Removal of Arsenate from Aqueous Systems

    OpenAIRE

    Pizarro,Carmen; Rubio,María A.; Escudey,Mauricio; Albornoz,María F.; Muñoz,Daniela; Denardin,Juliano; Fabris,José D.

    2015-01-01

    Composites based on nanosized particles of magnetite and natural microsized zeolite were prepared and their efficiency to adsorb arsenate from aqueous systems was evaluated through kinetic data and adsorption isotherms, considering the proportion of magnetic iron oxide, composite:solution ratio and zeolite particle size. A well-crystallized nanomagnetite with an averaged particle size of 50 nm when supported on zeolite was obtained; the nanomagnetite enhances the arsenate adsorption of zeolit...

  4. Composition Optimization and Stability Testing of a Parenteral Antifungal Solution based on a Ternary Solvent System

    OpenAIRE

    Kovács, Kristóf; Antal, István; Stampf, György; Klebovich, Imre; Ludányi, Krisztina

    2010-01-01

    An intravenous solution is a dosage forms intended for administration into the bloodstream. This route is the most rapid and the most bioavailable method of getting drugs into systemic circulation, and therefore it is also the most liable to cause adverse effects. In order to reduce the possibility of side effects and to ensure adequate clinical dosage of the formulation, the primarily formulated composition should be optimized. It is also important that the composition should retain its ther...

  5. Portable LIBS system for determining the composition of multilayer structures on objects of cultural value

    Energy Technology Data Exchange (ETDEWEB)

    Moreira Osorio, Lesther [IMRE-Havana University, Vedado 10400, Havana (Cuba); Ponce Cabrera, Luis V; Arronte Garcia, Miguel A; Flores Reyes, Teresa [CICATA-IPN, km 14.5 Carretera Tampico Puerto industrial, Altamira 89600, Tamps (Mexico); Ravelo, Ivette, E-mail: lesther.moreira@gmail.com [National Center for Conservation, Restoration and Museology (CENCREM) (Cuba)

    2011-01-01

    This study presents the use of a portable Laser Induced Breakdown Spectroscopy (LIBS) prototype for determining the elemental composition of a metal jug. The system includes emission from a multiuse Q-switched Nd:YAG laser. By sampling at different points, the surface composition is determined. Furthermore, the presence of two layers of Pb and Cu and their thicknesses are determined through in-depth analysis.

  6. Composition and enzymatic activity in bulk milk from dairy farms with conventional or robotic milking systems

    NARCIS (Netherlands)

    Johansson, Monika; Lundh, Åse; Vries, de Ruben; Sjaunja, Kerstin Svennersten

    2017-01-01

    The objective of the studies reported in this research communication was to investigate differences in composition and enzymatic activities in bulk milk samples provided from Swedish dairy farms with different management systems, i.e. automated (AMS) and conventional milking systems (CMS). A bulk

  7. Composition of Dirac structures and control of Port-Hamiltonian systems

    NARCIS (Netherlands)

    van der Schaft, Arjan; Cervera, J.; Gilliam, D.S.; Rosenthal, J.

    2002-01-01

    Key feature of Dirac structures (as opposed to Poisson or symplectic structures) is the fact that the standard composition of two Dirac structures is again a Dirac structure. In particular this implies that any power-conserving interconnection of port-Hamiltonian systems is a port-Hamiltonian system

  8. Compositional verification of multi-agent systems: A formal analysis of pro-activeness and reactiveness

    NARCIS (Netherlands)

    Jonker, C.M.; Treur, J.

    1998-01-01

    A compositional method is presented for the verification of multi-agent systems. The advantages of the method are the well-structuredness of the proofs and the reusability of parts of these proofs in relation to reuse of components. The method is illustrated for an example multi-agent system,

  9. Compositional verification of multi-agent systems: A formal analysis of pro-activeness and reactiveness.

    NARCIS (Netherlands)

    Jonker, C.M.; Treur, J.

    2002-01-01

    A compositional method is presented for the verification of multi-agent systems. The advantages of the method are the well-structuredness of the proofs and the reusability of parts of these proofs in relation to reuse of components. The method is illustrated for an example multi-agent system,

  10. Compositional verification of knowledge-based systems: A case study for diagnostic reasoning

    NARCIS (Netherlands)

    Cornelissen, F.J.; Jonker, C.M.; Treur, J.

    1997-01-01

    In this paper a compositional verification method for models of knowledge-based systems is introduced. Required properties of the system are formally verified by deriving them from assumptions that themselves are properties of sub-components, which in their turn may be derived from assumptions on

  11. A Decentralized Compositional Framework for Dependable Decision Process in Self-Managed Cyber Physical Systems.

    Science.gov (United States)

    Zhou, Peng; Zuo, Decheng; Hou, Kun-Mean; Zhang, Zhan

    2017-11-09

    Cyber Physical Systems (CPSs) need to interact with the changeable environment under various interferences. To provide continuous and high quality services, a self-managed CPS should automatically reconstruct itself to adapt to these changes and recover from failures. Such dynamic adaptation behavior introduces systemic challenges for CPS design, advice evaluation and decision process arrangement. In this paper, a formal compositional framework is proposed to systematically improve the dependability of the decision process. To guarantee the consistent observation of event orders for causal reasoning, this work first proposes a relative time-based method to improve the composability and compositionality of the timing property of events. Based on the relative time solution, a formal reference framework is introduced for self-managed CPSs, which includes a compositional FSM-based actor model (subsystems of CPS), actor-based advice and runtime decomposable decisions. To simplify self-management, a self-similar recursive actor interface is proposed for decision (actor) composition. We provide constraints and seven patterns for the composition of reliability and process time requirements. Further, two decentralized decision process strategies are proposed based on our framework, and we compare the reliability with the static strategy and the centralized processing strategy. The simulation results show that the one-order feedback strategy has high reliability, scalability and stability against the complexity of decision and random failure. This paper also shows a way to simplify the evaluation for dynamic system by improving the composability and compositionality of the subsystem.

  12. A Decentralized Compositional Framework for Dependable Decision Process in Self-Managed Cyber Physical Systems

    Directory of Open Access Journals (Sweden)

    Peng Zhou

    2017-11-01

    Full Text Available Cyber Physical Systems (CPSs need to interact with the changeable environment under various interferences. To provide continuous and high quality services, a self-managed CPS should automatically reconstruct itself to adapt to these changes and recover from failures. Such dynamic adaptation behavior introduces systemic challenges for CPS design, advice evaluation and decision process arrangement. In this paper, a formal compositional framework is proposed to systematically improve the dependability of the decision process. To guarantee the consistent observation of event orders for causal reasoning, this work first proposes a relative time-based method to improve the composability and compositionality of the timing property of events. Based on the relative time solution, a formal reference framework is introduced for self-managed CPSs, which includes a compositional FSM-based actor model (subsystems of CPS, actor-based advice and runtime decomposable decisions. To simplify self-management, a self-similar recursive actor interface is proposed for decision (actor composition. We provide constraints and seven patterns for the composition of reliability and process time requirements. Further, two decentralized decision process strategies are proposed based on our framework, and we compare the reliability with the static strategy and the centralized processing strategy. The simulation results show that the one-order feedback strategy has high reliability, scalability and stability against the complexity of decision and random failure. This paper also shows a way to simplify the evaluation for dynamic system by improving the composability and compositionality of the subsystem.

  13. Composite Bipolar Plate for Unitized Fuel Cell/Electrolyzer Systems

    Science.gov (United States)

    Mittelsteadt, Cortney K.; Braff, William

    2009-01-01

    In a substantial improvement over present alkaline systems, an advanced hybrid bipolar plate for a unitized fuel cell/electrolyzer has been developed. This design, which operates on pure feed streams (H2/O2 and water, respectively) consists of a porous metallic foil filled with a polymer that has very high water transport properties. Combined with a second metallic plate, the pore-filled metallic plates form a bipolar plate with an empty cavity in the center.

  14. Development of a Framework for Model-Based Analysis, Uncertainty Quantification, and Robust Control Design of Nonlinear Smart Composite Systems

    Science.gov (United States)

    2015-06-04

    A major component of the program focused on the development of this framework in the context of hysteretic macro -fiber composite (MFC) and shape...smart composite systems. A major component of the program focused on the development of this framework in the context of hysteretic macro -fiber composite...range of nonlinear and hysteretic smart composite systems. A major component of the program focused on the development of this framework in the context

  15. Design on a Composite Mobile System for Exploration Robot

    Directory of Open Access Journals (Sweden)

    Weiyan Shang

    2016-01-01

    Full Text Available In order to accomplish exploration missions in complex environments, a new type of robot has been designed. By analyzing the characteristics of typical moving systems, a new mobile system which is named wheel-tracked moving system (WTMS has been presented. Then by virtual prototype simulation, the new system’s ability to adapt complex environments has been verified. As the curve of centroid acceleration changes in large amplitude in this simulation, ride performance of this robot has been studied. Firstly, a simplified dynamic model has been established, and then by affecting factors analysis on ride performance, an optimization model for suspension parameters has been presented. Using NSGA-II method, a set of nondominated solutions for suspension parameters has been gotten, and by weighing the importance of the objective function, an optimal solution has been selected to be applied on suspension design. As the wheel-tracked exploration robot has been designed and manufactured, the property test has been conducted. By testing on physical prototype, the robot’s ability to surmount complex terrain has been verified. Design of the wheel-tracked robot will provide a stable platform for field exploration tasks, and in addition, the certain configuration and suspension parameters optimization method will provide reference to other robot designs.

  16. An exploratory examination of the relationship between motivational factors and the degree to which the higher education faculty integrate computer-mediated communication (CMC) tools into their courses

    Science.gov (United States)

    Murage, Francis Ndwiga

    The stated research problem of this study was to examine the relationship between motivational factors and the degree to which the higher education faculty integrate CMC tools into their courses. The study population and sample involved higher education faculty teaching in science departments at one public university and three public colleges in the state of West Virginia (N = 153). A Likert-type rating scale survey was used to collect data based on the research questions. Two parts of the survey were adopted from previous studies while the other two were self-constructed. Research questions and hypothesis were analyzed using both descriptive and inferential analyses. The study results established a positive relationship between motivational factors and the degree the higher education faculty integrate CMC tools in their courses. The results in addition established that faculty are highly motivated to integrate CMC tools by intrinsic factors, moderately motivated by environmental factors and least motivated by extrinsic factors. The results also established that the most integrated CMC tools were those that support asynchronous methods of communication while the least integrated were those that support synchronous methods of communication. A major conclusion made was that members of higher education faculty are more likely to be motivated to integrate CMC tools into their courses by intrinsic factors rather than extrinsic or environmental factors. It was further concluded that intrinsic factors that supported and enhanced student learning as well as those that were altruistic in nature significantly influenced the degree of CMC integration. The study finally concluded that to larger extent, there is a relationship between motivational factors and the degree to which the higher education faculty integrate CMC tools in their courses. A major implication of this study was that institutions that wish to promote integration of CMC technologies should provide as much

  17. Fiber gratings strain sensor systems for composites and adhesive joints

    Science.gov (United States)

    Scheel, Ingrid; Udd, Eric

    2017-04-01

    Fiber Bragg grating (FBG) and other fiber optic based sensors have been used to sense environmental parameters for numerous applications including aerospace, oil and gas, civil structure health monitoring, mining, and medical. There are many benefits to using fiber optic based sensors over traditional electrical sensing methods. These advantages include: immunity to electromagnetic interference, high bandwidth, low loss, small, lightweight, and portability. New developments allow these physical measurements such as strain, temperature, pressure, vibration, and acoustics to be made at extremely fast speeds extending the capability of fiber optic sensor systems to monitor impacts and other rapid events.

  18. Personality Types and Megabytes: Student Attitudes toward Computer Mediated Communication (CMC) in the Language Classroom.

    Science.gov (United States)

    Beauvois, Margaret Healy; Eledge, Jean

    1996-01-01

    Describes the results of a pilot study to examine the attitudes of university students toward the use of computer-mediated communication in their French conversation and composition course. Results indicate that both introvert and extrovert personality types generally perceive the use of a local area network as a beneficial experience. (15…

  19. Binary mixing of micelles using Pluronics for a nano-sized drug delivery system.

    Science.gov (United States)

    Lee, Eun Seong; Oh, Young Taik; Youn, Yu Seok; Nam, Myounghwa; Park, Byungtae; Yun, Jungmin; Kim, Ji Hoon; Song, Ho-Taek; Oh, Kyung Taek

    2011-01-01

    Pluronics with different structural compositions and properties are used for several applications, including drug delivery systems. We developed a binary mixing system with two Pluronics, L121/P123, as a nano-sized drug delivery carrier. The lamellar-forming Pluronic L121 (0.1 wt%) was incorporated with Pluronic P123 to produce nano-sized dispersions (in case of 0.1 and 0.5 wt% P123) with high stability due to Pluronic P123 and high solubilization capacity due to Pluronic L121. The binary systems were spherical and less than 200-nm diameter, with high thermodynamic stability (at least 2 weeks) in aqueous solution. The CMC of the binary system was located in the middle of the CMC of each polymer. In particular, the solubilization capacity of the binary system (0.1/0.1 wt%) was higher than mono-systems of P123. The main advantage of binary systems is overcoming limitations of mono systems to allow tailored mixing of block copolymers with different physicochemical characteristics. These nano-sized systems may have potential as anticancer drug delivery systems with simple preparation method, high stability, and high loading capacity. Copyright © 2010 Elsevier B.V. All rights reserved.

  20. Rapid Prototyping of Continuous Fiber Reinforced Ceramic Matrix Composites

    Science.gov (United States)

    Vaidyanathan, R.; Green, C.; Phillips, T.; Cipriani, R.; Yarlagadda, S.; Gillespie, J. W., Jr.; Effinger, M.; Cooper, K. C.

    2003-01-01

    For ceramics to be used as structural components in high temperature applications, their fracture toughness is improved by embedding continuous ceramic fibers. Ceramic matrix composite (CMC) materials allow increasing the overall operating temperature, raising the temperature safety margins, avoiding the need for cooling, and improving the damping capacity, while reducing the weight at the same time. They also need to be reliable and available in large quantities as well. In this paper, an innovative rapid prototyping technique to fabricate continuous fiber reinforced ceramic matrix composites is described. The process is simple, robust and will be widely applicable to a number of high temperature material systems. This technique was originally developed at the University of Delaware Center for Composite Materials (UD-CCM) for rapid fabrication of polymer matrix composites by a technique called automated tow placement or ATP. The results of mechanical properties and microstructural characterization are presented, together with examples of complex shapes and parts. It is believed that the process will be able to create complex shaped parts at an order of magnitude lower cost than current chemical vapor infiltration (CVI) and polymer impregnation and pyrolysis (PIP) processes.

  1. Design of 3D-Printable Conductive Composites for 3D-Printed Battery

    OpenAIRE

    Park, Jae Sung

    2016-01-01

    In this research, a biocompatible nano-composite is designed for the application of 3D printed battery. The nano-composite paste is composed of an electrically conductive silver nanowire (AgNW) filler within a thixotropic carboxymethyl cellulose (CMC) matrix. Experimental demonstration and computational simulations on nano-composites with various filler fractions are performed to find the electrical percolation threshold of the nano-composite. The percolation threshold as 0.7 vol. % of AgNWs ...

  2. A Process Mining Based Service Composition Approach for Mobile Information Systems

    Directory of Open Access Journals (Sweden)

    Chengxi Huang

    2017-01-01

    Full Text Available Due to the growing trend in applying big data and cloud computing technologies in information systems, it is becoming an important issue to handle the connection between large scale of data and the associated business processes in the Internet of Everything (IoE environment. Service composition as a widely used phase in system development has some limits when the complexity of relationship among data increases. Considering the expanding scale and the variety of devices in mobile information systems, a process mining based service composition approach is proposed in this paper in order to improve the adaptiveness and efficiency of compositions. Firstly, a preprocessing is conducted to extract existing service execution information from server-side logs. Then process mining algorithms are applied to discover the overall event sequence with preprocessed data. After that, a scene-based service composition is applied to aggregate scene information and relocate services of the system. Finally, a case study that applied the work in mobile medical application proves that the approach is practical and valuable in improving service composition adaptiveness and efficiency.

  3. Automated diagnostic systems with diverse and composite features for Doppler ultrasound signals.

    Science.gov (United States)

    Güler, Inan; Ubeyli, Elif Derya

    2006-10-01

    In this paper, we present the automated diagnostic systems for Doppler ultrasound signals classification with diverse and composite features and determine their accuracies. We compared the classification accuracies of six different classifiers, namely multilayer perceptron neural network (MLP), combined neural network (CNN), mixture of experts (ME), modified mixture of experts (MME), probabilistic neural network (PNN), and support vector machine (SVM), which were trained on diverse or composite features. The present study was conducted with the purpose of answering the question of whether the automated diagnostic systems improve the capability of classification of ophthalmic arterial (OA) and internal carotid arterial (ICA) Doppler signals. Our research demonstrated that the SVM trained on composite feature and the MME trained on diverse features achieved accuracy rates which were higher than that of the other automated diagnostic systems.

  4. Composite Intelligent Learning Control of Strict-Feedback Systems With Disturbance.

    Science.gov (United States)

    Xu, Bin; Sun, Fuchun

    2018-02-01

    This paper addresses the dynamic surface control of uncertain nonlinear systems on the basis of composite intelligent learning and disturbance observer in presence of unknown system nonlinearity and time-varying disturbance. The serial-parallel estimation model with intelligent approximation and disturbance estimation is built to obtain the prediction error and in this way the composite law for weights updating is constructed. The nonlinear disturbance observer is developed using intelligent approximation information while the disturbance estimation is guaranteed to converge to a bounded compact set. The highlight is that different from previous work directly toward asymptotic stability, the transparency of the intelligent approximation and disturbance estimation is included in the control scheme. The uniformly ultimate boundedness stability is analyzed via Lyapunov method. Through simulation verification, the composite intelligent learning with disturbance observer can efficiently estimate the effect caused by system nonlinearity and disturbance while the proposed approach obtains better performance with higher accuracy.

  5. Tool for Generation of MAC/GMC Representative Unit Cell for CMC/PMC Analysis

    Science.gov (United States)

    Murthy, Pappu L. N.; Pineda, Evan J.

    2016-01-01

    This document describes a recently developed analysis tool that enhances the resident capabilities of the Micromechanics Analysis Code with the Generalized Method of Cells (MAC/GMC) 4.0. This tool is especially useful in analyzing ceramic matrix composites (CMCs), where higher fidelity with improved accuracy of local response is needed. The tool, however, can be used for analyzing polymer matrix composites (PMCs) as well. MAC/GMC 4.0 is a composite material and laminate analysis software developed at NASA Glenn Research Center. The software package has been built around the concept of the generalized method of cells (GMC). The computer code is developed with a user friendly framework, along with a library of local inelastic, damage, and failure models. Further, application of simulated thermomechanical loading, generation of output results, and selection of architectures to represent the composite material have been automated to increase the user friendliness, as well as to make it more robust in terms of input preparation and code execution. Finally, classical lamination theory has been implemented within the software, wherein GMC is used to model the composite material response of each ply. Thus, the full range of GMC composite material capabilities is available for analysis of arbitrary laminate configurations as well. The primary focus of the current effort is to provide a graphical user interface (GUI) capability that generates a number of different user-defined repeating unit cells (RUCs). In addition, the code has provisions for generation of a MAC/GMC-compatible input text file that can be merged with any MAC/GMC input file tailored to analyze composite materials. Although the primary intention was to address the three different constituents and phases that are usually present in CMCs-namely, fibers, matrix, and interphase-it can be easily modified to address two-phase polymer matrix composite (PMC) materials where an interphase is absent. Currently, the

  6. Calibration of 3D Woven Preform Design Code for CMC Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Future hypersonic vehicles will utilize thermal protection system (TPS) designs and propulsion system components that are capable of experiencing high temperatures...

  7. Urban stormwater runoff nitrogen composition and fate in bioretention systems.

    Science.gov (United States)

    Li, Liqing; Davis, Allen P

    2014-03-18

    Multiple chemical forms of nitrogen in urban stormwater make its management challenging. Sixteen storm events were monitored and analyzed for total nitrogen (TN), particulate organic nitrogen (PON), nitrate (NO3-N), nitrite (NO2-N), ammonium (NH3-N), and dissolved organic nitrogen (DON) in stormwater runoff and in treated discharge through a conventional bioretention cell. Influent PON can be effectively removed via bioretention sedimentation/filtration, NH3-N by ion exchange/sorption, and NO2-N by oxidation. However, significant DON and NO3-N leached from the bioretention cell, resulting in only 9% net overall TN concentration reduction. Captured PON and vegetation detritus in the bioretention cell can be leached as DON or mineralized into NO3-N. The effluent N is dominated by NO3-N (46%) and DON (42%). Therefore, in addition to creating denitrification conditions for NO3-N, preventing DON leaching is also critical for effective nitrogen removal though bioretention systems. The bioretention cell exhibited a moderate mass load reduction for TN (41%), which mainly results from runoff volume reduction.

  8. Compatibility between dental adhesive systems and dual-polymerizing composite resins.

    Science.gov (United States)

    Michaud, Pierre-Luc; MacKenzie, Alexandra

    2016-10-01

    Information is lacking about incompatibilities between certain types of adhesive systems and dual-polymerizing composite resins, and universal adhesives have yet to be tested with these resins. The purpose of this in vitro study was to investigate the bonding outcome of dual-polymerizing foundation composite resins by using different categories of adhesive solutions and to determine whether incompatibilities were present. One hundred and eighty caries-free, extracted third molar teeth were allocated to 9 groups (n=20), in which 3 different bonding agents (Single Bond Plus [SB]), Scotchbond Multi-purpose [MP], and Scotchbond Universal [SU]) were used to bond 3 different composite resins (CompCore AF [CC], Core Paste XP [CP], and Filtek Supreme Ultra [FS]). After restorations had been fabricated using an Ultradent device, the specimens were stored in water at 37°C for 24 hours. The specimens were tested under shear force at a rate of 0.5 mm/min. The data were analyzed with Kruskal-Wallis tests and post hoc pairwise comparisons (α=.05). All 3 composite resins produced comparable shear bond strengths when used with MP (P=.076). However, when either SB or SU was used, the light-polymerized composite resin (FS) and 1 dual-polymerized foundation composite resin (CC) bonded significantly better than the other dual-polymerized foundation composite resin (CP) (Presins can obtain equally good bond strengths as light-polymerizing alternatives. However, not all dual-polymerizing composite resins perform well with all bonding systems; some incompatibilities exist between different products. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  9. DC conductivity and magnetic properties of piezoelectric-piezomagnetic composite system

    Science.gov (United States)

    Hemeda, O. M.; Tawfik, A.; A-Al-Sharif; Amer, M. A.; Kamal, B. M.; El Refaay, D. E.; Bououdina, M.

    2012-11-01

    A series of composites (1-x) (Ni0.8Zn0.2Fe2O4)+x (BaTiO3), where x=0%, 20%, 40%, 60%, 80% and 100% BT content, have been prepared by the standard ceramic technique, then sintered at 1200 °C for 8 h. X-ray diffraction analysis shows that the prepared composites consist of two phases, ferrimagnetic and ferroelectric. DC electrical resistivity, thermoelectric power, charge carriers concentration and charge carrier mobility have been studied at different temperatures. It was found that the DC electrical conductivity increases with increasing BT content. The values of the thermoelectric power were positive and negative for the composites indicating that there are two conduction mechanisms, hopping and band conduction, respectively. Using the values of DC electrical conductivity and thermoelectric power, the values of charge carrier mobility and the charge carrier concentration were calculated. Magnetic measurements (hysteresis loop and magnetic permeability) show that the magnetization decreases by increasing BT content. M-H loop of pure Ni0.6 Zn0.4 Fe2O4 composite indicates that it is paramagnetic at room temperature and that the magnetization is diluted by increasing the BT content in the composite system. The value of magnetoelectric coefficient for the composites decreases by increasing BT content for all the compositions except for 40% BT content, which may be due to the low resistivity of magnetic phase compared with the BT phase that causes a leakage of induced charges on the piezoelectric phase. Since both ferroelectric and magnetic phases preserve their basic properties in the bulk composite, the present BT-NZF composite are potential candidates for applications as pollution sensors and electromagnetic waves.

  10. Investigating the Roles of Motivation and Technological Pedagogical Content Knowledge (TPACK in Computer-Mediated-Communication (CMC Speaking Skills Instruction

    Directory of Open Access Journals (Sweden)

    Nor Azlina Binti Muhamad

    2014-03-01

    Full Text Available The computer-mediated approach is deemed as an effective way to assist in improving the communicative skills among ESL learners. This study presents a mixed-methods research. It aims to identify the level of motivation of the CMC users in learning English speaking skills, and how they relate to speaking achievements. This research investigates how the content knowledge (CK, pedagogical knowledge (PK and the technological knowledge (TK of the facilitators influence the motivation of the learners. Data is analysed comparing the Pre-Post tests. Inferential Statistics method which uses the correlation analysis is carried out to see the relationship between the factors and the level of the speaking competency. Moreover, the data is triangulated with the inclusion of audio- taped interview data. 154 students and 4 language facilitators were randomly selected from one of the institutes of higher education in Malaysia. The findings indicate that the learners’ speaking competency levels show significant improvement compared to the early stage of the research. However, there is no significant difference between the results of pre-post tests in terms of the motivation level and results also did not show significant relationship between motivation and the improvement of the speaking competency level. This shows that motivation level was not the leading factor that influenced improvement in the proficiency levels of the students.  The interviews with the ESL learners showed that they had dissatisfactions regarding their online learning programme and they also indicated that their facilitators lacked of Content, Pedagogical and Technological Knowledge (TCPK in facilitating their online learning as these knowledge are important in the online learning environment. As the conclusion, ESL learners improved their speaking proficiency through CMC learning but there are other external factors beyond the scope of this research that need to be investigated further.

  11. [Photoelastic stress analysis of root dentin with different composite resin post and core systems and crowns].

    Science.gov (United States)

    Takei, Hidenori

    2010-03-01

    Much research has been reported about post and core systems with composite resin, but the influence of the different types of prefabricated posts on the distribution of stress in the root has not yet been elucidated. It is necessary to clarify the influence of the relationship between core and crown materials to obtain combined restorations. The aim of this study is to analyze the influence of the combination of various post and core systems and different kinds of crown material on the stress distribution in the root. Six 2-dimensional photoelastic premolar models were designed. Three types of post and core systems (composite resin post and core, composite resin core with the fiber post, and composite resin core with a prefabricated stainless steel post) and two kinds of crown materials (metal and hybrid-type hard composite resin) were fabricated and cemented to each model. In these models, we applied a load of 200 N at an angle of 45 degrees to the tooth axis and analyzed the fringe order using a transmission polariscope. As a result, it has been clarified that the combination of the post and core and the crown plays an important role in preventing stress concentration within root Stress concentration can be prevented using a crown fabricated with a high-elastic modulus for the post and core with a high-elastic modulus, and a crown fabricated with a low-elastic modulus for the post and core with a low-elastic modulus.

  12. Advanced resin systems and 3D textile preforms for low cost composite structures

    Science.gov (United States)

    Shukla, J. G.; Bayha, T. D.

    1993-01-01

    Advanced resin systems and 3D textile preforms are being evaluated at Lockheed Aeronautical Systems Company (LASC) under NASA's Advanced Composites Technology (ACT) Program. This work is aimed towards the development of low-cost, damage-tolerant composite fuselage structures. Resin systems for resin transfer molding and powder epoxy towpreg materials are being evaluated for processability, performance and cost. Three developmental epoxy resin systems for resin transfer molding (RTM) and three resin systems for powder towpregging are being investigated. Various 3D textile preform architectures using advanced weaving and braiding processes are also being evaluated. Trials are being conducted with powdered towpreg, in 2D weaving and 3D braiding processes for their textile processability and their potential for fabrication in 'net shape' fuselage structures. The progress in advanced resin screening and textile preform development is reviewed here.

  13. Surface properties of an indirect composite polymerized with five laboratory light polymerization systems.

    Science.gov (United States)

    Murakami, Mahoko

    2009-06-01

    A study was conducted to evaluate the influence of laboratory light polymerization systems on the post-curing properties of a composite. An indirect composite (Sinfony) was polymerized with five polymerization systems (Visio system, Hyper LII, Pearlcure Light, Twinkle MIII, and UniXS II) using nine polymerization modes. After light exposure, Knoop hardness number, wear depth, and changes in gloss were determined. The highest hardness number was recorded with the use of the Hyper LII (120 s) and Pearlcure Light (120 s) units, whereas the lowest value was obtained with the Visio system and UniXS II (60 s). Six groups demonstrated comparable as well as higher wear resistance to toothbrush abrasion (Hyper LII 60 and 120 s, UniXS II 120 s, Pearlcure Light 60 and 120 s, and Twinkle MIII 120 s), and two groups exhibited lower wear resistance (Visio system and UniXS II 60 s). Gloss of the composite was not dependent on the polymerization mode used before wear testing. However, surface gloss was significantly reduced by toothbrush dentifrice abrasion. Within the limitations of the present experiment, it can be concluded that the Sinfony composite can be polymerized sufficiently with high-intensity light polymerization units.

  14. Bond strength of a composite resin to glass ionomer cements using different adhesive systems

    Directory of Open Access Journals (Sweden)

    Ana Carolina de Oliveira BECCI

    2017-08-01

    Full Text Available Abstract Introduction Glass ionomer cements are often used as a base or cavity lining prior to restorative material. Objective To evaluate the bond strength of a composite resin to different glass ionomer cements, when using a two-step conventional and self-etching adhesive systems. Material and method Three glass ionomer cements (Ketac Molar Easymix, Vitremer and Vitrebond, the composite resin Filtek Z350 XT and the adhesive systems Adper Single Bond 2, Clearfil SE Bond and Adper Easy One were used. As negative control, resin was bonded to cement without using an adhesive system. Holes (4 mm diameter, 2 mm deep prepared in acrilic bloks were filled with the glass ionomer cements (n=12/group. On the surface, an area of 1mm in diameter was delimited, the adhesive system was applied, and a specimen of composite resin with 1 mm height was made. After 24 hours storage (37 °C and 100% humidity, the microshear test was performed. Data were analyzed using two-way ANOVA and Tukey test for comparison between groups (α=0.05. Result The adhesive systems significantly improved the bond strenght of composite resin to glass ionomer cements (p≤0.001. There was no significant difference in bond strength when self-etching adhesive systems were compared with the simplified etch-and-rinse adhesive, except for Vitrebond where Clearfil SE Bond determined higher bond strength when compared to Adper Single Bond 2 (p=0.003. Conclusion Self-etching adhesive systems are a good option for establishing the bond between the composite resin and the glass ionomer cement.

  15. Impact Responses of Composite Cushioning System considering Critical Component with Simply Supported Beam Type

    Directory of Open Access Journals (Sweden)

    Fu-de Lu

    2014-04-01

    Full Text Available In some microelectronic products, one or several components can be idealized as simply supported beam type and viewed as vulnerable elements or critical component due to the fact that they are destroyed easily under impact loadings. The composite cushioning structure made of expanded polyethylene (EPE, and expanded polystyrene (EPS was utilized to protect the vulnerable elements against impact loadings during transportation. The vibration equations of composite cushioning system were deducted and virtual mass method was applied to predict impact behavior of critical component. Numerical results indicate that virtual mass method is appropriate for computing impact response of composite cushioning system with vulnerable element of simply supported beam type, which is affirmed by the fact that the impact responses of structure element in terms of velocity- and displacement-time curves are almost unchanged when virtual mass is smaller than a certain value. The results in this paper make it possible for installation of packaging optimization design.

  16. Grazing effects on forage production and botanical composition in a Quercus ithaburensis subs. macrolepis silvopastoral system

    Science.gov (United States)

    Pantera, A.; Papanastasis, V. P.

    2009-04-01

    Grazing is considered as a major factor affecting forage production as well as botanical composition of many silvopastoral systems. In order to study these effects, three pairs of grazed and protected plots were established in a Quercus ithaburensis subsp. macrolepis silvopastoral system. The experiment was carried out in western Greece, 15 km west of the city of Agrinion. Data were collected for two continuous years and included the determination of palatable and unpalatable to animals plant species as well as the botanical composition. The results suggest that heavy grazing decreased biomass production approximately threefold. Grazing also affected number of acorns, botanical composition as well as vegetation cover whereas had no effect on natural regeneration in the study period.

  17. Preparation and biological properties of a novel composite scaffold of nano-hydroxyapatite/chitosan/carboxymethyl cellulose for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Chengdong Xiong

    2009-07-01

    Full Text Available Abstract In this study, we report the physico-chemical and biological properties of a novel biodegradable composite scaffold made of nano-hydroxyapatite and natural derived polymers of chitosan and carboxymethyl cellulose, namely, n-HA/CS/CMC, which was prepared by freeze-drying method. The physico-chemical properties of n-HA/CS/CMC scaffold were tested by infrared absorption spectra (IR, transmission electron microscope(TEM, scanning electron microscope(SEM, universal material testing machine and phosphate buffer solution (PBS soaking experiment. Besides, the biological properties were evaluated by MG63 cells and Mesenchymal stem cells (MSCs culture experiment in vitro and a short period implantation study in vivo. The results show that the composite scaffold is mainly formed through the ionic crossing-linking of the two polyions between CS and CMC, and n-HA is incorporated into the polyelectrolyte matrix of CS-CMC without agglomeration, which endows the scaffold with good physico-chemical properties such as highly interconnected porous structure, high compressive strength and good structural stability and degradation. More important, the results of cells attached, proliferated on the scaffold indicate that the scaffold is non-toxic and has good cell biocompatibility, and the results of implantation experiment in vivo further confirm that the scaffold has good tissue biocompatibility. All the above results suggest that the novel degradable n-HA/CS/CMC composite scaffold has a great potential to be used as bone tissue engineering material.

  18. Predictive Local Composition Models for Solid/Liquid Equilibrium in n-Alkane Systems: Wilson Equation for Multicomponent Systems

    DEFF Research Database (Denmark)

    Coutinho, João A.P.; Stenby, Erling Halfdan

    1996-01-01

    The predictive local composition model is applied to multicomponent hydrocarbon systems with long-chain n-alkanes as solutes. The results show that it can successfully be extended to highorder systems and accurately predict the solid appearance temperature, also known as cloud point, in solutions...... by considering the multiple orthorhombic phases as a single phase. It is shown that for low concentrations in heavy fraction the interaction parameter (alpha)_ls can be neglected and thus the model becomes purely predictive....

  19. Initial development of goCMC: a GPU-oriented fast cross-platform Monte Carlo engine for carbon ion therapy

    Science.gov (United States)

    Qin, Nan; Pinto, Marco; Tian, Zhen; Dedes, Georgios; Pompos, Arnold; Jiang, Steve B.; Parodi, Katia; Jia, Xun

    2017-05-01

    Monte Carlo (MC) simulation is considered as the most accurate method for calculation of absorbed dose and fundamental physics quantities related to biological effects in carbon ion therapy. To improve its computational efficiency, we have developed a GPU-oriented fast MC package named goCMC, for carbon therapy. goCMC simulates particle transport in voxelized geometry with kinetic energy up to 450 MeV u-1. Class II condensed history simulation scheme with a continuous slowing down approximation was employed. Energy straggling and multiple scattering were modeled. δ-electrons were terminated with their energy locally deposited. Four types of nuclear interactions were implemented in goCMC, i.e. carbon-hydrogen, carbon-carbon, carbon-oxygen and carbon-calcium inelastic collisions. Total cross section data from Geant4 were used. Secondary particles produced in these interactions were sampled according to particle yield with energy and directional distribution data derived from Geant4 simulation results. Secondary charged particles were transported following the condensed history scheme, whereas secondary neutral particles were ignored. goCMC was developed under OpenCL framework and is executable on different platforms, e.g. GPU and multi-core CPU. We have validated goCMC with Geant4 in cases with different beam energy and phantoms including four homogeneous phantoms, one heterogeneous half-slab phantom, and one patient case. For each case 3× {{10}7} carbon ions were simulated, such that in the region with dose greater than 10% of maximum dose, the mean relative statistical uncertainty was less than 1%. Good agreements for dose distributions and range estimations between goCMC and Geant4 were observed. 3D gamma passing rates with 1%/1 mm criterion were over 90% within 10% isodose line except in two extreme cases, and those with 2%/1 mm criterion were all over 96%. Efficiency and code portability were tested with different GPUs and CPUs. Depending on the beam

  20. Initial development of goCMC: a GPU-oriented fast cross-platform Monte Carlo engine for carbon ion therapy.

    Science.gov (United States)

    Qin, Nan; Pinto, Marco; Tian, Zhen; Dedes, Georgios; Pompos, Arnold; Jiang, Steve B; Parodi, Katia; Jia, Xun

    2017-05-07

    Monte Carlo (MC) simulation is considered as the most accurate method for calculation of absorbed dose and fundamental physics quantities related to biological effects in carbon ion therapy. To improve its computational efficiency, we have developed a GPU-oriented fast MC package named goCMC, for carbon therapy. goCMC simulates particle transport in voxelized geometry with kinetic energy up to 450 MeV u -1 . Class II condensed history simulation scheme with a continuous slowing down approximation was employed. Energy straggling and multiple scattering were modeled. δ-electrons were terminated with their energy locally deposited. Four types of nuclear interactions were implemented in goCMC, i.e. carbon-hydrogen, carbon-carbon, carbon-oxygen and carbon-calcium inelastic collisions. Total cross section data from Geant4 were used. Secondary particles produced in these interactions were sampled according to particle yield with energy and directional distribution data derived from Geant4 simulation results. Secondary charged particles were transported following the condensed history scheme, whereas secondary neutral particles were ignored. goCMC was developed under OpenCL framework and is executable on different platforms, e.g. GPU and multi-core CPU. We have validated goCMC with Geant4 in cases with different beam energy and phantoms including four homogeneous phantoms, one heterogeneous half-slab phantom, and one patient case. For each case [Formula: see text] carbon ions were simulated, such that in the region with dose greater than 10% of maximum dose, the mean relative statistical uncertainty was less than 1%. Good agreements for dose distributions and range estimations between goCMC and Geant4 were observed. 3D gamma passing rates with 1%/1 mm criterion were over 90% within 10% isodose line except in two extreme cases, and those with 2%/1 mm criterion were all over 96%. Efficiency and code portability were tested with different GPUs and CPUs. Depending on the

  1. Konut Transformasyonu Bağlamında Lefke’deki CMC Evlerinin Zaman İçerisindeki Dönüşümü / The Gradual Transformation of CMC Houses in Lefke within the Context of Housing Transformation

    Directory of Open Access Journals (Sweden)

    Çağla Beyaz

    2017-06-01

    Full Text Available Abstract This study aims to determine the reflections of the factors affecting the gradual change of the houses constructed for the American mining company CMC (Cyprus Mines Corporation in Lefke between 1916 and 1974. Research has shown that such factors as life standards, needs, politics, environmental factors, climate, geography and cultural factors have changed the housing demand. Having taken all these factors into consideration, we have reached a conclusion regarding the transformation of the houses by analysing the collected data by field research techniques appropriate to CMC houses in Lefke. The field research has been conducted by taking samples from each category and analysing them; and the gradual transformation and the underlying environmental factors have been determined. The field research techniques used in the study are interviews, photos, relieves and archive research. In the result obtained from the general work; Along with the rapid development caused by the effects of the Industrial Revolution, religious, cultural, economical, political and architectural conditions have been shaped in different forms and values. Along with these circumstances, the changes and transformations that observed in the world and affecting the cities have also affected Cyprus Island. In the Lefke region, along with the establishment of the CMC, the positive and negative effects of the terraced houses, built for the first time in Cyprus in four different categories and their close surroundings, draw quite attention. In the study, the transformations of these houses until today and the factors affecting them have been also determined. Öz Çalışma, Lefke Bölgesinde 1916-1974 yılları arasında faaliyet gösteren Amerikan maden şirketi CMC (Cyprus Mines Corporation için yapılmış olan konutların zaman içerisindeki form değişimine etki eden faktörlerin, konut mekânına olan etkilerini saptamaya yöneliktir. Konut ihtiyacının, yaşam

  2. AWSCS-A System to Evaluate Different Approaches for the Automatic Composition and Execution of Web Services Flows.

    Science.gov (United States)

    Tardiole Kuehne, Bruno; Estrella, Julio Cezar; Nunes, Luiz Henrique; Martins de Oliveira, Edvard; Hideo Nakamura, Luis; Gomes Ferreira, Carlos Henrique; Carlucci Santana, Regina Helena; Reiff-Marganiec, Stephan; Santana, Marcos José

    2015-01-01

    This paper proposes a system named AWSCS (Automatic Web Service Composition System) to evaluate different approaches for automatic composition of Web services, based on QoS parameters that are measured at execution time. The AWSCS is a system to implement different approaches for automatic composition of Web services and also to execute the resulting flows from these approaches. Aiming at demonstrating the results of this paper, a scenario was developed, where empirical flows were built to demonstrate the operation of AWSCS, since algorithms for automatic composition are not readily available to test. The results allow us to study the behaviour of running composite Web services, when flows with the same functionality but different problem-solving strategies were compared. Furthermore, we observed that the influence of the load applied on the running system as the type of load submitted to the system is an important factor to define which approach for the Web service composition can achieve the best performance in production.

  3. Principles of Linguistic Composition Below and Beyond the Clause—Elements of a semantic combinatorial system

    DEFF Research Database (Denmark)

    Bundgaard, Peer

    2006-01-01

    beyond the scope of the clause. To this end it exposes two major principles of semantic combination that are active through all levels of linguistic composition: viz. frame-schematic structure and narrative structure. These principles are considered as being components of a semantic combinatorial system...

  4. INVESTIGATION OF TITANIUM BONDED GRAPHITE FOAM COMPOSITES FOR MICRO ELECTRONIC MECHANICAL SYSTEMS (MEMS) APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Menchhofer, Paul A [ORNL; Bozorgi, Payam [ORNL

    2016-04-01

    PiMEMS Inc. (Santa Barbara, CA) in collaboration with ORNL investigated the use of Titanium Bonded Graphite Foam Composites (TBGC) for thermal mitigation in Micro Electronic Mechanical Systems (MEMS) applications. Also considered were potentially new additive manufacturing routes to producing novel high surface area micro features and diverse shaped heat transfer components for numerous lightweight MEMs applications.

  5. Bond strength durability of a resin composite on a reinforced ceramic using various repair systems

    NARCIS (Netherlands)

    Ozcan, Mutlu; Valandro, Luiz Felipe; Amaral, Regina; Leite, Fabiola; Bottino, Marco Antonio

    2009-01-01

    Objectives. This study compared the durability of repair bond strength of a resin composite to a reinforced ceramic after three repair systems. Methods. Alumina-reinforced feldspathic ceramic blocks (Vitadur-alpha(R)) (N=30) were randomly divided into three groups according to the repair method:

  6. Exploration of a digital audio processing platform using a compositional system level performance estimation framework

    DEFF Research Database (Denmark)

    Tranberg-Hansen, Anders Sejer; Madsen, Jan

    2009-01-01

    This paper presents the application of a compositional simulation based system-level performance estimation framework on a non-trivial industrial case study. The case study is provided by the Danish company Bang & Olufsen ICEpower a/s and focuses on the exploration of a digital mobile audio...

  7. Synthesis and Characterization of Hybrid CF/MWCNTS/Epoxy Resin Composite System

    Science.gov (United States)

    Fouda, Hany; Guo, Lin; Yue, Yonghai; Chen, Ke; Elsharkawy, Karim

    2017-07-01

    In the present investigation, two methods were used for addition multiwall carbon nanotubes (MWCNTS) into carbon fiber (CF)/epoxy resin composite system. The mechanical properties of the prepared samples were compared to show the best method for addition of MWCNTS from point of view of mechanical properties. The introduction of carbon nanotubes (CNTs) into fiber reinforced polymer composites has been achieved mainly via two routes: mixing CNTs entirely throughout the matrix (matrix modification) or attaching CNTs onto reinforcing fibers (interface modification). In all previous references the addition of CNTs occur through one route from the two routes but in this research, we introduced MWCNTS into CF/epoxy resin composite through the two routes at the same time. Three CF composite samples were prepared CF/epoxy resin composite (C1), CF/1wt% MWCNTS /epoxy resin composite (C2) in which MWCNTS added via one route (epoxy resin system) and the third sample was CF/1wt% MWCNTS / epoxy resin composite (C3) in which MWCNTS added via two routes (epoxy resin and CF fabric). The result shows that the mechanical properties of C3>C2>C1, for example, the flexural strength of C3 higher than C2 by 19% and C2 higher than C1 by 51% respectively. This is because addition MWCNTS via two routes increase the ability of good mixing of CNTS with epoxy resin and good dispersion of CNTs into the CF fabric surface and this leads to improve the interface bonding between the CF and epoxy so improve the mechanical properties.

  8. Investigation of Carboxymethyl Cellulose (CMC on Mechanical Properties of Cold Water Fish Gelatin Biodegradable Edible Films

    Directory of Open Access Journals (Sweden)

    Mahsa Tabari

    2017-05-01

    Full Text Available The tendency to use biocompatible packages, such as biodegradable films, is growing since they contain natural materials, are recyclable and do not cause environmental pollution. In this research, cold water fish gelatin and carboxymethyl cellulose were combined for use in edible films. Due to its unique properties, gelatin is widely used in creating gel, and in restructuring, stabilizing, emulsifying, and forming foam and film in food industries. This research for the first time modified and improved the mechanical properties of cold water fish gelatin films in combination with carboxymethyl cellulose. Cold water fish gelatin films along with carboxymethyl cellulose with concentrations of 0%, 5%, 10%, 20% and 50% were prepared using the casting method. The mechanical properties were tested by the American National Standard Method. Studying the absorption isotherm of the resulting composite films specified that the humidity of single-layer water decreased (p < 0.05 and caused a reduction in the equilibrium moisture of these films. In the mechanical testing of the composite films, the tensile strength and Young’s modulus significantly increased and the elongation percent significantly decreased with the increase in the concentration of carboxymethyl cellulose. Considering the biodegradability of the films and the improvement of their mechanical properties by carboxymethyl cellulose, this kind of packaging can be used in different industries, especially the food industry, as an edible coating for packaging food and agricultural crops.

  9. Application of a Fiber Optic Distributed Strain Sensor System to Woven E-Glass Composite

    Science.gov (United States)

    Anastasi, Robert F.; Lopatin, Craig

    2001-01-01

    A distributed strain sensing system utilizing a series of identically written Bragg gratings along an optical fiber is examined for potential application to Composite Armored Vehicle health monitoring. A vacuum assisted resin transfer molding process was used to fabricate a woven fabric E-glass/composite panel with an embedded fiber optic strain sensor. Test samples machined from the panel were mechanically tested in 4-point bending. Experimental results are presented that show the mechanical strain from foil strain gages comparing well to optical strain from the embedded sensors. Also, it was found that the distributed strain along the sample length was consistent with the loading configuration.

  10. In vitro testing of an experimental dental composite resin and adhesive system.

    Science.gov (United States)

    Alb, Camelia; Alb, S; Dudea, Diana; Nicola, Codruţa; Moldovan, Mărioara; Culic, B; Buduru, Smaranda; Mesaros, Anca

    2010-01-01

    In vitro testing of new experimental materials has been introduced for many years as a method to evaluate them in simulated conditions, before the clinical trials. Our study has investigated a new experimental composite resin C1 and adhesive system Ad1 by scanning electron microscope (SEM) studies and microleakage tests. Both in vitro test were performed on extracted human teeth, that were prepared for standardized class II and V restorations and restored with three composite resins (experimental C1, TetricCeram TC and Solitaire2 S2) and their total-etch adhesive systems (Ad1, Excite EX and GlumaOneBond GB). Teeth were sectioned and investigated under the SEM microscope for the interfaces created and under the optical microscope for dye penetration and microleakage. The Romanian experimental composite C1 has shown lower alpha "ideal" interfaces than TC and S2, with no significant difference between the latter. Microleakage was significantly lower at the enamel margin and significantly higher at the gingival margin placed below the CEJ for all three compared composites. C1 presented similar dye penetration scores with the commercial available systems. The differences in SEM analysis can be attributed to higher viscosity and handling properties in the experimental adhesive Adl and to technique sensitivity. Further investigation is required to obtain better working properties for the experimental adhesive and higher "ideal" scores at the interfaces. Also the SEM investigation is more sensitive than the optical microscope analysis.

  11. The effect of various polishing systems on the surface roughness of composite resins

    Directory of Open Access Journals (Sweden)

    Didem Atabek

    2016-05-01

    Full Text Available OBJECTIVE: The aim of this in vitro study was to evaluate the effect of three finishing and polishing systems on the surface roughness of nano-manufactured composite resins. MATERIALS AND METHOD: Nano-ceramic Ceram-X (Dentsply DeTrey, Konstanz, Germany, nano-filled Premise (Kerr Corporation, Orange, NJ, USA and nano-filled Clearfil Majestic (Kuraray Medical Inc., Tokyo, Japan composite resins were tested. Forty samples of each material were cured under matrix strips. The samples were then randomly assigned into four test groups: 1 unpolished; 2 polished with burs out of resin reinforced by zircon-rich glass fiber (Stainbuster, Abrasive Technology, Inc., Lewis Center, OH, USA; 3 polished with aluminum oxide impregnated polymer points (Enhance Finishing System, Dentsply Caulk, Milford, DE, USA followed by diamond impregnated micro-polishing points (PoGo, Dentsply Caulk; and 4 polished with aluminum oxide disks (Sof-Lex, Dentsply Caulk. The sample surface roughness values (Ra were determined using a profilometer, and the surfaces were observed under a scanning electron microscope. Data were analyzed using the Kruskal-Wallis test. RESULTS: No statistically significant differences in surface roughness were detected among the finishing and polishing systems (p>0.05. However, all finishing and polishing techniques created statistically rougher surfaces than the control group (p<0.05. The mean Ra values of the finishing and polishing systems were ranked as follows: Mylar strip < Enhance Finishing System+PoGo < Stainbuster < Sof-Lex. These findings were confirmed by scanning electron microscope photomicrographs. CONCLUSION: All polishing systems produced clinically acceptable surface roughness on the tested composite materials. The smoothest surfaces were achieved using the nano-ceramic composites with the Enhance Finishing System and PoGo.

  12. Fiber Bragg Grating Sensor System for Monitoring Smart Composite Aerospace Structures

    Science.gov (United States)

    Moslehi, Behzad; Black, Richard J.; Gowayed, Yasser

    2012-01-01

    Lightweight, electromagnetic interference (EMI) immune, fiber-optic, sensor- based structural health monitoring (SHM) will play an increasing role in aerospace structures ranging from aircraft wings to jet engine vanes. Fiber Bragg Grating (FBG) sensors for SHM include advanced signal processing, system and damage identification, and location and quantification algorithms. Potentially, the solution could be developed into an autonomous onboard system to inspect and perform non-destructive evaluation and SHM. A novel method has been developed to massively multiplex FBG sensors, supported by a parallel processing interrogator, which enables high sampling rates combined with highly distributed sensing (up to 96 sensors per system). The interrogation system comprises several subsystems. A broadband optical source subsystem (BOSS) and routing and interface module (RIM) send light from the interrogation system to a composite embedded FBG sensor matrix, which returns measurand-dependent wavelengths back to the interrogation system for measurement with subpicometer resolution. In particular, the returned wavelengths are channeled by the RIM to a photonic signal processing subsystem based on powerful optical chips, then passed through an optoelectronic interface to an analog post-detection electronics subsystem, digital post-detection electronics subsystem, and finally via a data interface to a computer. A range of composite structures has been fabricated with FBGs embedded. Stress tensile, bending, and dynamic strain tests were performed. The experimental work proved that the FBG sensors have a good level of accuracy in measuring the static response of the tested composite coupons (down to submicrostrain levels), the capability to detect and monitor dynamic loads, and the ability to detect defects in composites by a variety of methods including monitoring the decay time under different dynamic loading conditions. In addition to quasi-static and dynamic load monitoring, the

  13. Update on CMH-17 Volume 5 Ceramic Matrix Composites

    Science.gov (United States)

    Andrulonis, Rachael; Kiser, J. Douglas; David, Kaia E.; Davies, Curtis R.; Ashforth, Cindy

    2017-01-01

    A wide range of issues must be addressed during the process of certifying CMC (ceramic matrix composite) components for use in commercial aircraft. The Composite Materials Handbook-17, Volume 5, Revision A on ceramic matrix composites has just been revised to help support FAA certification of CMCs for elevated temperature applications. The handbook supports the development and use of CMCs through publishing and maintaining proven, reliable engineering information and standards that have been thoroughly reviewed. Volume 5 contains detailed sections describing CMC materialsprocessing design, analysisguidelines, testing procedures, and data analysis and acceptance. A review of the content of this latest revision will be presented along with a description of how CMH-17, Volume 5 could be used by the FAA (Federal Aviation Administration) and others in the future.

  14. Design and analysis of a novel latch system implementing fiber-reinforced composite materials

    Science.gov (United States)

    Guevara Arreola, Francisco Javier

    The use of fiber-reinforced composite materials have increased in the last four decades in high technology applications due to their exceptional mechanical properties and low weight. In the automotive industry carbon fiber have become popular exclusively in luxury cars because of its high cost. However, Carbon-glass hybrid composites offer an effective alternative to designers to implement fiber-reinforced composites into several conventional applications without a considerable price increase maintaining most of their mechanical properties. A door latch system is a complex mechanism that is under high loading conditions during car accidents such as side impacts and rollovers. Therefore, the Department of Transportation in The United States developed a series of tests that every door latch system comply in order to be installed in a vehicle. The implementation of fiber-reinforced composite materials in a door latch system was studied by analyzing the material behavior during the FMVSS No. 206 transverse test using computational efforts and experimental testing. Firstly, a computational model of the current forkbolt and detent structure was developed. Several efforts were conducted in order to create an effective and time efficient model. Two simplified models were implemented with two different contact interaction approaches. 9 composite materials were studied in forkbolt and 5 in detent including woven carbon fiber, unidirectional carbon fiber, woven carbon-glass fiber hybrid composites and unidirectional carbon-glass fiber hybrid composites. The computational model results showed that woven fiber-reinforced composite materials were stiffer than the unidirectional fiber-reinforced composite materials. For instance, a forkbolt made of woven carbon fibers was 20% stiffer than a forkbolt made of unidirectional fibers symmetrically stacked in 0° and 90° alternating directions. Furthermore, Hybrid composite materials behaved as expected in forkbolt noticing a decline

  15. Implementation of Fiber Optic Sensing System on Sandwich Composite Cylinder Buckling Test

    Science.gov (United States)

    Pena, Francisco; Richards, W. Lance; Parker, Allen R.; Piazza, Anthony; Schultz, Marc R.; Rudd, Michelle T.; Gardner, Nathaniel W.; Hilburger, Mark W.

    2018-01-01

    The National Aeronautics and Space Administration (NASA) Engineering and Safety Center Shell Buckling Knockdown Factor Project is a multicenter project tasked with developing new analysis-based shell buckling design guidelines and design factors (i.e., knockdown factors) through high-fidelity buckling simulations and advanced test technologies. To validate these new buckling knockdown factors for future launch vehicles, the Shell Buckling Knockdown Factor Project is carrying out structural testing on a series of large-scale metallic and composite cylindrical shells at the NASA Marshall Space Flight Center (Marshall Space Flight Center, Alabama). A fiber optic sensor system was used to measure strain on a large-scale sandwich composite cylinder that was tested under multiple axial compressive loads up to more than 850,000 lb, and equivalent bending loads over 22 million in-lb. During the structural testing of the composite cylinder, strain data were collected from optical cables containing distributed fiber Bragg gratings using a custom fiber optic sensor system interrogator developed at the NASA Armstrong Flight Research Center. A total of 16 fiber-optic strands, each containing nearly 1,000 fiber Bragg gratings, measuring strain, were installed on the inner and outer cylinder surfaces to monitor the test article global structural response through high-density real-time and post test strain measurements. The distributed sensing system provided evidence of local epoxy failure at the attachment-ring-to-barrel interface that would not have been detected with conventional instrumentation. Results from the fiber optic sensor system were used to further refine and validate structural models for buckling of the large-scale composite structures. This paper discusses the techniques employed for real-time structural monitoring of the composite cylinder for structural load introduction and distributed bending-strain measurements over a large section of the cylinder by

  16. Composition optimization and stability testing of a parenteral antifungal solution based on a ternary solvent system.

    Science.gov (United States)

    Kovács, Kristóf; Antal, István; Stampf, György; Klebovich, Imre; Ludányi, Krisztina

    2010-03-01

    An intravenous solution is a dosage forms intended for administration into the bloodstream. This route is the most rapid and the most bioavailable method of getting drugs into systemic circulation, and therefore it is also the most liable to cause adverse effects. In order to reduce the possibility of side effects and to ensure adequate clinical dosage of the formulation, the primarily formulated composition should be optimized. It is also important that the composition should retain its therapeutic effectiveness and safety throughout the shelf-life of the product. This paper focuses on the optimization and stability testing of a parenteral solution containing miconazole and ketoconazole solubilized with a ternary solvent system as model drugs. Optimization of the solvent system was performed based on assessing the risk/benefit ratio of the composition and its properties upon dilution. Stability tests were conducted based on the EMEA (European Medicines Agency) "guideline on stability testing: stability testing of existing active substances and related finished products". Experiments show that both the amount of co-solvent and surface active agent of the solvent system could substantially be reduced, while still maintaining adequate solubilizing power. It is also shown that the choice of various containers affects the stability of the compositions. It was concluded that by assessing the risk/benefit ratio of solubilizing power versus toxicity, the concentration of excipients could be considerably decreased while still showing a powerful solubilizing effect. It was also shown that a pharmaceutically acceptable shelf-life could be assigned to the composition, indicating good long-term stability.

  17. Micromechanics, fracture mechanics and gas permeability of composite laminates for cryogenic storage systems

    Science.gov (United States)

    Choi, Sukjoo

    A micromechanics method is developed to investigate microcrack propagation in a liquid hydrogen composite tank at cryogenic temperature. The unit cell is modeled using square and hexagonal shapes depends on fiber and matrix layout from microscopic images of composite laminates. Periodic boundary conditions are applied to the unit cell. The temperature dependent properties are taken into account in the analysis. The laminate properties estimated by the micromechanics method are compared with empirical solutions using constituent properties. The micro stresses in the fiber and matrix phases based on boundary conditions in laminate level are calculated to predict the formation of microcracks in the matrix. The method is applied to an actual liquid hydrogen storage system. The analysis predicts micro stresses in the matrix phase are large enough to cause microcracks in the composite. Stress singularity of a transverse crack normal to a ply-interface is investigated to predict the fracture behavior at cryogenic conditions using analytical and finite element analysis. When a transverse crack touches a ply-interface of a composite layer with same fiber orientation, the stress singularity is equal to ½. When the transverse crack propagates to a stiffer layer normal to a ply-direction, the singularity becomes less than ½ and vice versa. Finite element analysis is performed to evaluate fracture toughness of a laminated beam subjected to the fracture load measured by the fracture experiment at room and cryogenic temperatures. As results, the fracture load at cryogenic temperature is significantly lower than that at room temperature. However, when thermal stresses are taken into consideration, for both cases of room and cryogenic temperatures, the variation of fracture toughness becomes insignificant. The result indicates fracture toughness is a characteristic property which is independent to temperature changes. The experimental analysis is performed to investigate the

  18. Experimental Investigations of Composite Adsorbent 13X/CaCl2 on an Adsorption Cooling System

    Directory of Open Access Journals (Sweden)

    Huizhong Zhao

    2017-06-01

    Full Text Available A new experimental device which tests the adsorption performance of the 13X/CaCl2 composite adsorbent under vacuum conditions was established. In this device, heat transfer characteristics in the adsorbent bed have a great influence on the adsorbent performance, the temperature of the bottom outside bed is very close to the temperature of the bottom inside bed and the temperature difference between them at the end of heating and cooling are 5.66 °C and 0.303 °C, respectively. The following conclusions could be drawn: the equilibrium water uptake of composite adsorbent CA10X (zeolite 13X impregnated with 10 wt % CaCl2 solution was increased 5.7% compared with that of 13X, and the water uptake was 0.37 g/g. The composite adsorbent CA10X has a better performance in the adsorption refrigeration system.

  19. DISCO: An object-oriented system for music composition and sound design

    Energy Technology Data Exchange (ETDEWEB)

    Kaper, H. G.; Tipei, S.; Wright, J. M.

    2000-09-05

    This paper describes an object-oriented approach to music composition and sound design. The approach unifies the processes of music making and instrument building by using similar logic, objects, and procedures. The composition modules use an abstract representation of musical data, which can be easily mapped onto different synthesis languages or a traditionally notated score. An abstract base class is used to derive classes on different time scales. Objects can be related to act across time scales, as well as across an entire piece, and relationships between similar objects can replicate traditional music operations or introduce new ones. The DISCO (Digital Instrument for Sonification and Composition) system is an open-ended work in progress.

  20. Fabrication of Ni-Al/diamond composite based on layered and gradient structures of SHS system

    Directory of Open Access Journals (Sweden)

    Lu Jiafeng

    2017-01-01

    Full Text Available In this paper layered and gradient structures of Ni-Al SHS system were adopted to manufacture Ni-Al/diamond composites. The effect of the layered and the diamond mesh gradient structures of Ni-Al/diamond on the SHS process and the microstructure of the composites were investigated. It is found that with the increasing of the number of layers, the combustion wave velocity is decreased. The combustion wave velocity for diamond mesh size gradient structure of Ni-Al SHS is faster than that for the layered structure. A well bonding can be formed between diamond and the matrix in layered and gradient structure Ni-Al/diamond composites due to the melt of Ni-Cr brazing alloy.

  1. Characterization of EPS compositions and microbial community in an Anammox SBBR system treating landfill leachate.

    Science.gov (United States)

    Miao, Lei; Zhang, Qiong; Wang, Shuying; Li, Baikun; Wang, Zhong; Zhang, Sujian; Zhang, Man; Peng, Yongzhen

    2017-09-23

    The biofilm system is beneficial for Anammox process designed to treat landfill leachate. In this study, the composition of extracellular polymeric substances (EPS) and the microbial community in an Anammox biofilm system were analyzed to determine the functions driving the biofilm's ability to treat landfill leachate. The results demonstrated that increasing influent carbon oxygen demand (COD) could stimulate EPS production. EPS helped enrich Anammox bacteria and supplied them with nutrients and enzymes, facilitating effective nitrogen removal (approximately 95%). The variation in Anammox bacteria was similar to the variation in EPS composition. In the tested Anammox Sequencing Biofilm Batch Reactor (SBBR) system, Candidatus Kuenenia was dominant among known Anammox genus, because of its high substrate affinity and because it adapts better to landfill leachate. The relative abundance of Candidatus Kuenenia in the biofilm rose from 3.26% to 12.38%, illustrating the protection and enrichment offered by the biofilm in carrying out Anammox. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. WATER BINDING IN COMPOSITE SYSTEMS BASED ON MILLED MEDICINAL PLANTS AND NANOSILICA

    Directory of Open Access Journals (Sweden)

    V. V. Turov

    2017-04-01

    Full Text Available The aim of the study was to identify the influence of hydrodensified nanosilica particles on the binding of water by milled plant raw materials in neutral and acidic media. Flowers of Hibiscus sabdariffa and Calendula officinalis were used as the model materials. According to the microphotographs and low temperature 1H NMR spectroscopy data, the silica film forms on the surface of the milled plant particles, and it can significantly influence their hydration. According to the suggested scheme, some of the water from the inner cavities of plant raw materials moves (as evidenced by the decreasing radius of water-filled pores to the zone of contact of the composite components (the radius of clusters of adsorbed water increases. In studies of desorption of active substances from milled medicinal herbs and their composites by the initial and hydrodensified nanosilica, it has been shown that the formation of a composite significantly reduces the rate of desorption. Minimal desorption is observed in composites containing hydrodensified nanosilica. The studied composite systems are promising for biomedical researches.

  3. Lightweight Ultrahigh Temperature CMC-Encased C/C Structure for Reentry and Hypersonic Applications Project

    Data.gov (United States)

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

  4. 5-year clinical performance of resin composite versus resin modified glass ionomer restorative system in non-carious cervical lesions

    DEFF Research Database (Denmark)

    Franco, Eduardo Batista; Benetti, Ana Raquel; Ishikiriama, Sérgio Kiyoshi

    2006-01-01

    To comparatively assess the 5-year clinical performance of a 1-bottle adhesive and resin composite system with a resin-modified glass ionomer restorative in non-carious cervical lesions.......To comparatively assess the 5-year clinical performance of a 1-bottle adhesive and resin composite system with a resin-modified glass ionomer restorative in non-carious cervical lesions....

  5. High temperature C/C–SiC composite by liquid silicon infiltration: a ...

    Indian Academy of Sciences (India)

    Abstract. The ceramic matrix carbon fibre (CMC) reinforced composite has received great attention for use in aerospace engineering. In aerospace, the atmosphere is highly oxidative and experiences very high temperature. In addition to this, the materials require high thermal stability and high abrasion resistance in that ...

  6. High temperature C/C–SiC composite by liquid silicon infiltration: a ...

    Indian Academy of Sciences (India)

    The ceramic matrix carbon fibre (CMC) reinforced composite has received great attention for use in aerospace engineering. In aerospace, the atmosphere is highly oxidative and experiences very high temperature. In addition to this, the materials require high thermal stability and high abrasion resistance in that atmosphere.

  7. Defects in Ceramic Matrix Composites and Their Impact on Elastic Properties (Postprint)

    Science.gov (United States)

    2013-07-01

    average void content of 6–7%, were used to render a 3D image containing Nomenclature CMC ceramic matrix composites SiNC silicon–nitride–carbide E...to two reasons: (i) Organic and inorganic groups oxidize or evaporate as well as a partial reform of the polymer structure due to crystallization

  8. FEAMAC/CARES Stochastic-Strength-Based Damage Simulation Tool for Ceramic Matrix Composites

    Science.gov (United States)

    Nemeth, Noel; Bednarcyk, Brett; Pineda, Evan; Arnold, Steven; Mital, Subodh; Murthy, Pappu; Bhatt, Ramakrishna

    2016-01-01

    Reported here is a coupling of two NASA developed codes: CARES (Ceramics Analysis and Reliability Evaluation of Structures) with the MAC/GMC (Micromechanics Analysis Code/ Generalized Method of Cells) composite material analysis code. The resulting code is called FEAMAC/CARES and is constructed as an Abaqus finite element analysis UMAT (user defined material). Here we describe the FEAMAC/CARES code and an example problem (taken from the open literature) of a laminated CMC in off-axis loading is shown. FEAMAC/CARES performs stochastic-strength-based damage simulation response of a CMC under multiaxial loading using elastic stiffness reduction of the failed elements.

  9. Stochastic-Strength-Based Damage Simulation Tool for Ceramic Matrix Composite

    Science.gov (United States)

    Nemeth, Noel; Bednarcyk, Brett; Pineda, Evan; Arnold, Steven; Mital, Subodh; Murthy, Pappu

    2015-01-01

    Reported here is a coupling of two NASA developed codes: CARES (Ceramics Analysis and Reliability Evaluation of Structures) with the MAC/GMC (Micromechanics Analysis Code/ Generalized Method of Cells) composite material analysis code. The resulting code is called FEAMAC/CARES and is constructed as an Abaqus finite element analysis UMAT (user defined material). Here we describe the FEAMAC/CARES code and an example problem (taken from the open literature) of a laminated CMC in off-axis loading is shown. FEAMAC/CARES performs stochastic-strength-based damage simulation response of a CMC under multiaxial loading using elastic stiffness reduction of the failed elements.

  10. Bond Strength of Composite Resin to Pulp Capping Biomaterials after Application of Three Different Bonding Systems

    Directory of Open Access Journals (Sweden)

    Zahra Jaberi-Ansari

    2013-08-01

    Full Text Available Background and aims. Bonding of composite resin filling materials to pulp protecting agents produces an adhesive joint which is important for the quality of filling as well as success of restoration. We aimed to assess the bond strength of composite resin to three pulp capping biomaterials: Pro Root mineral trioxide aggregate (PMTA, Root MTA (RMTA and calcium enriched mixture (CEM cement, using three bonding systems [a total-etch (Single Bond and two self-etch systems (Protect bond and SE Bond]. Materials and methods. Ninety acrylic molds, each containing a 6×2-mm hole, were divided into 3 groups and filled with PMTA, RMTA and CEM cements. The samples in each experimental group were then randomly divided into 3 subgroups; Single Bond, Protect Bond and SE Bond bonding systems were applied to the tested materials. Cylindrical forms of composite resin (Z100, 2×2 mm were placed onto the samples and cured. Shear bond strength values were measured for 9 subgroups using a universal testing machine. Data were analyzed using two-way ANOVA. Results. The average shear bond strengths of Z100 composite resin after application of Single Bond, Protect Bond and SE Bond systems were as follows; PMTA: 5.1±2.42, 4.56±1.96 and 4.52±1.7; RMTA: 4.71±1.77, 4.31±0.56 and 4.79±1.88; and CEM cement: 4.75±1.1, 4.54±1.59 and 4.64±1.78 MPa, respectively. The type of pulp capping material, bonding system and their interacting effects did not have a significant effect on the bond strengths of composite resin to pulp capping biomaterials. Conclusion. Within the limitations of this in vitro study, bond strength of composite resin to two types of MTA as well as CEM cement were similar following application of the total-etch or self-etch bonding systems.

  11. Potential of milk fatty acid composition to predict diet composition and authenticate feeding systems and altitude origin of European bulk milk.

    Science.gov (United States)

    Coppa, M; Chassaing, C; Ferlay, A; Agabriel, C; Laurent, C; Borreani, G; Barcarolo, R; Baars, T; Kusche, D; Harstad, O M; Verbič, J; Golecký, J; Delavaud, C; Chilliard, Y; Martin, B

    2015-03-01

    The aims of this work were to elucidate the potential of using milk fatty acid (FA) concentration to predict cow diet composition and altitude of bulk milk collected in 10 different European countries and to authenticate cow-feeding systems and altitude of the production area using a data set of 1,248 bulk cow milk samples and associated farm records. The predictions based on FA for cow diet composition were excellent for the proportions of fresh herbage [coefficient of determination (R2)=0.81], good for hay, total herbage-derived forages, and total preserved forages (R2>0.73), intermediate for corn silage and grass silage (R2>0.62), and poor for concentrates (R2diet. Milk samples were assigned to groups according to feeding system, level of concentrate supplementation, and altitude origin. Milk FA composition successfully authenticated cow-feeding systems dominated by a main forage (>93% of samples correctly classified), but the presence of mixed diets reduced the discrimination. Altitude prediction reliability was intermediate (R2composition was not able to authenticate concentrate supplementation level in the diet (composition (composition to authenticate cow feeding was confirmed using a data set representative of the diversity of European production conditions. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  12. Human intestinal microbiota composition is associated with local and systemic inflammation in obesity.

    Science.gov (United States)

    Verdam, Froukje J; Fuentes, Susana; de Jonge, Charlotte; Zoetendal, Erwin G; Erbil, Runi; Greve, Jan Willem; Buurman, Wim A; de Vos, Willem M; Rensen, Sander S

    2013-12-01

    Intestinal microbiota have been suggested to contribute to the development of obesity, but the mechanism remains elusive. The relationship between microbiota composition, intestinal permeability, and inflammation in nonobese and obese subjects was investigated. Fecal microbiota composition of 28 subjects (BMI 18.6-60.3 kg m(-2) ) was analyzed by a phylogenetic profiling microarray. Fecal calprotectin and plasma C-reactive protein levels were determined to evaluate intestinal and systemic inflammation. Furthermore, HbA1c , and plasma levels of transaminases and lipids were analyzed. Gastroduodenal, small intestinal, and colonic permeability were assessed by a multisaccharide test. Based on microbiota composition, the study population segregated into two clusters with predominantly obese (15/19) or exclusively nonobese (9/9) subjects. Whereas intestinal permeability did not differ between clusters, the obese cluster showed reduced bacterial diversity, a decreased Bacteroidetes/Firmicutes ratio, and an increased abundance of potential proinflammatory Proteobacteria. Interestingly, fecal calprotectin was only detectable in subjects within the obese microbiota cluster (n = 8/19, P = 0.02). Plasma C-reactive protein was also increased in these subjects (P = 0.0005), and correlated with the Bacteroidetes/Firmicutes ratio (rs = -0.41, P = 0.03). Intestinal microbiota alterations in obese subjects are associated with local and systemic inflammation, suggesting that the obesity-related microbiota composition has a proinflammatory effect. Copyright © 2013 The Obesity Society.

  13. Shear Bond Strength between Fiber-Reinforced Composite and Veneering Resin Composites with Various Adhesive Resin Systems.

    Science.gov (United States)

    AlJehani, Yousef A; Baskaradoss, Jagan K; Geevarghese, Amrita; AlShehry, Marey A; Vallittu, Pekka K

    2016-07-01

    The aim of this research was to evaluate the shear bond strength of different laboratory resin composites bonded to a fiber-reinforced composite substrate with some intermediate adhesive resins. Mounted test specimens of a bidirectional continuous fiber-reinforced substrate (StickNet) were randomly assigned to three equal groups. Three types of commercially available veneering resin composites - BelleGlass®, Sinfony®, and GC Gradia® were bonded to these specimens using four different adhesive resins. Half the specimens per group were stored for 24 hours; the remaining were stored for 30 days. There were 10 specimens in the test group (n). The shear bond strengths were calculated and expressed in MPa. Data were analyzed statistically, and variations in bond strength within each group were additionally evaluated by calculating the Weibull modulus. Shear bond values of those composites are influenced by the different bonding resins and different indirect composites. There was a significant difference in the shear bond strengths using different types of adhesive resins (p = 0.02) and using different veneering composites (p veneering composite to bidirectional continuous fiber-reinforced substrate is influenced by the brand of the adhesive resin and veneering composite. © 2015 by the American College of Prosthodontists.

  14. Improved Fabrication of Ceramic Matrix Composite/Foam Core Integrated Structures

    Science.gov (United States)

    Hurwitz, Frances I.

    2009-01-01

    The use of hybridized carbon/silicon carbide (C/SiC) fabric to reinforce ceramic matrix composite face sheets and the integration of such face sheets with a foam core creates a sandwich structure capable of withstanding high-heatflux environments (150 W/cm2) in which the core provides a temperature drop of 1,000 C between the surface and the back face without cracking or delamination of the structure. The composite face sheet exhibits a bilinear response, which results from the SiC matrix not being cracked on fabrication. In addition, the structure exhibits damage tolerance under impact with projectiles, showing no penetration to the back face sheet. These attributes make the composite ideal for leading edge structures and control surfaces in aerospace vehicles, as well as for acreage thermal protection systems and in high-temperature, lightweight stiffened structures. By tailoring the coefficient of thermal expansion (CTE) of a carbon fiber containing ceramic matrix composite (CMC) face sheet to match that of a ceramic foam core, the face sheet and the core can be integrally fabricated without any delamination. Carbon and SiC are woven together in the reinforcing fabric. Integral densification of the CMC and the foam core is accomplished with chemical vapor deposition, eliminating the need for bond-line adhesive. This means there is no need to separately fabricate the core and the face sheet, or to bond the two elements together, risking edge delamination during use. Fibers of two or more types are woven together on a loom. The carbon and ceramic fibers are pulled into the same pick location during the weaving process. Tow spacing may be varied to accommodate the increased volume of the combined fiber tows while maintaining a target fiber volume fraction in the composite. Foam pore size, strut thickness, and ratio of face sheet to core thickness can be used to tailor thermal and mechanical properties. The anticipated CTE for the hybridized composite is managed by

  15. Effect of different polishing systems on the surface roughness of nano-hybrid composites.

    Science.gov (United States)

    Patel, Brijesh; Chhabra, Naveen; Jain, Disha

    2016-01-01

    The study aimed to investigate the influence of different polishing systems on the surface roughness of nano-hybrid composite resins. Different shapes of polishing systems are available according to the site of work. To minimize variability, a new system with single shape is developed that can be utilized in both anterior as well as posterior teeth. Seventy composite discs were fabricated using Teflon well (10 mm × 3 mm). Two main group of nano-hybrid composite Group I - Filtek Z350 and Group II - Tetric N-Ceram were used (n = 35 for each group). Both groups were further divided into four subgroups. Subgroup a - OneGloss (n = 10), Subgroup b - PoGo (n = 10), Subgroup c - Sof-Lex spiral (n = 10), Subgroup d - Mylar strip (control, n = 5). Samples were polished according to the manufacturer's recommendations. Surface roughness test was performed using contact profilometer. The obtained data were analyzed using the one-way analysis of variance test. Tetric N-Ceram produced smoother surfaces than Filtek Z350 (P system than "OneGloss" and "Sof-Lex Spiral."

  16. Multi-scale thermodynamic analysis method for 2D SiC/SiC composite turbine guide vanes

    Directory of Open Access Journals (Sweden)

    Xin LIU

    2018-01-01

    Full Text Available Ceramic Matrix Composite (CMC turbine guide vanes possess multi-scale stress and strain with inhomogeneity at the microscopic scale. Given that the macroscopic distribution cannot reflect the microscopic stress fluctuation, the macroscopic method fails to meet the requirements of stress and strain analysis of CMC turbine guide vanes. Furthermore, the complete thermodynamic properties of 2D woven SiC/SiC-CMC cannot be obtained through experimentation. Accordingly, a method to calculate the thermodynamic properties of CMC and analyze multi-scale stress and strain of the turbine guide vanes should be established. In this study, the multi-scale thermodynamic analysis is investigated. The thermodynamic properties of Chemical Vapor Infiltration (CVI processed SiC/SiC-CMC are predicted by a Representative Volume Element (RVE model with porosity, leading to the result that the relative error between the calculated in-plane tensile modulus and the experimental value is 4.2%. The macroscopic response of a guide vane under given conditions is predicted. The relative error between the predicted strain on the trailing edge and the experimental value is 9.7%. The calculation of the stress distribution of micro-scale RVE shows that the maximum value of microscopic stress, which is located in the interlayer matrix, is more than 1.5 times that of macroscopic stress in the same direction and the microscopic stress distribution of the interlayer matrix is related to the pore distribution of the composite.

  17. Examination of decision support systems for composite CBA & MCDA assessments of transport infrastructure projects

    DEFF Research Database (Denmark)

    Barfod, Michael Bruhn; Jensen, Anders Vestergaard; Leleur, Steen

    This paper examines decision support systems (DSS) for composite appraisals of transport infrastructure projects comprising both cost-benefit analysis (CBA) and multi-criteria analysis (MCA). Two DSS are in this context examined and compared using a case study dealing with alternatives for a new...... different set of axioms. However, the two systems provide the decision makers with the same kind of result, only expressed differently. The question treated in this context is hence if the COSIMA system provides the decision makers with some information that the conventional system does not provide and vice...... high-speed railway line between the two cities, Norrköping and Bäckeby, in Sweden. Both systems are based on additive value functions and makes use of pair wise comparisons. The first system examined, which is widely used and based on acknowledged methods, comprises the REMBRANDT technique using pair...

  18. Comparison of results from different NDE techniques from ceramic matrix composites with varying porosity levels

    Science.gov (United States)

    Smyth, Imelda; Ojard, Greg; Santhosh, Unni; Ahmad, Jalees; Gowayed, Yasser

    2015-03-01

    Ceramic matrix composites (CMC's) are attractive materials for use in advanced turbine engines. Due to the nature of available processing techniques, however, the amount and distribution of porosity in CMC's can vary greatly. This can be particularly true in parts with complex geometries. It is therefore important to characterize the porosity with non-destructive techniques and understand its effect on properties. A series of CMC samples were fabricated with varying levels of porosity and analyzed with different NDE techniques. The results were categorized and analyzed with respect to ease of interpretation and degree to which they could be quantified and used in models to determine the effects of defects. The results were also correlated with microstructural examination and mechanical properties.

  19. Comparison of Shear Bond Strength between Composite Resin and Porcelain Using Different Bonding Systems

    Directory of Open Access Journals (Sweden)

    E.Yassini

    2005-03-01

    Full Text Available Statement of Problem: Ceramics as in ceramo-metallic and all ceramic tooth restorations have grown popular owing to their high tissue compatibility and esthetic advantages. Such restorations have the capability to deliver valuable services over a long period of time; however, failures under intraoral conditions are not unanticipated.Purpose: The purpose of this in-vitro study was to investigate the shear bond strength of composite resin to porcelain using different bonding system materials.Materials and Methods: In this experimental study forty porcelain blocks were prepared and randomly divided into four equal groups. The porcelain surfaces were then etched with HF for 2 minutes, washed with water for 2 minutes and treated with a silane layer. The silane treated porcelain surfaces were left for one minute and then the specimens were bonded to composite resin as follow:Group 1 (control group, hybrid composite Z100 was applied and light cured from four directions for 20 seconds. Group 2, flowable composite was applied and light cured for 20 seconds. Group 3, unfilled resin was used and photo cured for 20 seconds. Group 4,(Dentin bonding agent adhesive resin was used followed by 20 seconds photo curing.Hybrid composite resin Z100 was subsequently applied on all porcelain surfaces of groups 2, 3 and 4, and light cured for 20 seconds from four directions. Specimens were then subjected to thermocycling 1000 times. Shear bond strength was determined by a Universal testing machine. The data obtained was subjected to a one-way ANOVA test.Results: The results indicate that there is a statistically significant difference between adhesive group and the other three groups of hybrid, flowable and unfilled resin (P<0.05.Conclusion: The results from this study showed that the shear bond strength of composite resin to porcelain was significantly higher for porcelain bonded surfaces using a dentin bonding agent than that of other materials tested.

  20. Optimization of Composite Material System and Lay-up to Achieve Minimum Weight Pressure Vessel

    Science.gov (United States)

    Mian, Haris Hameed; Wang, Gang; Dar, Uzair Ahmed; Zhang, Weihong

    2013-10-01

    The use of composite pressure vessels particularly in the aerospace industry is escalating rapidly because of their superiority in directional strength and colossal weight advantage. The present work elucidates the procedure to optimize the lay-up for composite pressure vessel using finite element analysis and calculate the relative weight saving compared with the reference metallic pressure vessel. The determination of proper fiber orientation and laminate thickness is very important to decrease manufacturing difficulties and increase structural efficiency. In the present work different lay-up sequences for laminates including, cross-ply [ 0 m /90 n ] s , angle-ply [ ±θ] ns , [ 90/±θ] ns and [ 0/±θ] ns , are analyzed. The lay-up sequence, orientation and laminate thickness (number of layers) are optimized for three candidate composite materials S-glass/epoxy, Kevlar/epoxy and Carbon/epoxy. Finite element analysis of composite pressure vessel is performed by using commercial finite element code ANSYS and utilizing the capabilities of ANSYS Parametric Design Language and Design Optimization module to automate the process of optimization. For verification, a code is developed in MATLAB based on classical lamination theory; incorporating Tsai-Wu failure criterion for first-ply failure (FPF). The results of the MATLAB code shows its effectiveness in theoretical prediction of first-ply failure strengths of laminated composite pressure vessels and close agreement with the FEA results. The optimization results shows that for all the composite material systems considered, the angle-ply [ ±θ] ns is the optimum lay-up. For given fixed ply thickness the total thickness of laminate is obtained resulting in factor of safety slightly higher than two. Both Carbon/epoxy and Kevlar/Epoxy resulted in approximately same laminate thickness and considerable percentage of weight saving, but S-glass/epoxy resulted in weight increment.

  1. Screening of osteoanagenesis-active compounds from Scutellaria baicalensis Georgi by hPDLC/CMC-online-HPLC/MS.

    Science.gov (United States)

    Liu, Jin; Wang, Sicen; Sun, Junyi; Shi, Jianfeng; Li, Ye; Gou, Jianzhong; Li, Ang; He, Langchong

    2014-03-01

    In present study, an online analytical method using human periodontal ligament cell/cell membrane chromatography (hPDLC/CMC) combined with high-performance liquid chromatography/mass spectrometry (HPLC/MS) was used for direct recognition, separation, and identification of compounds for the first time from Scutellaria baicalensis Georgi (SBG) that are active on hPDLCs. Baicalein (BAI) and wogonin (WOG), which were identified as the active compounds of the ethyl ether extract of S. baicalensis Georgi (SBGEE), could bind to the same membrane receptor of hPDLC for simvastatin (SIM). Moreover, BAI (0.15-0.6 mg/L) and WOG (0.015-0.6 mg/L) had the capability to enhance cell proliferation, matrix calcification, and formation of calcified nodules, which are comparable to the activities of SIM (0.1 mg/L) in vitro. These observations are consistent with the K(A) of the various drugs. It is very important for the development of SBG used to treat periodontitis. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Determination of cmc of imidazolium based surface active ionic liquids through probe-less UV-vis spectrophotometry.

    Science.gov (United States)

    Rather, Mudasir Ahmad; Rather, Ghulam Mohammad; Pandit, Sarwar Ahmad; Bhat, Sajad Ahmad; Bhat, Mohsin Ahmad

    2015-01-01

    In the first of its kind we herein report the results of our studies undertaken on the micellization behaviour of imidazolium based surface active ionic liquids (SAILs) to prove that their critical micelle concentration (cmc) can be estimated through ultraviolet-visible (UV-vis) spectroscopy without using any external probe. Tensiometric and spectrophotometric investigations of a series of freshly prepared SAILs viz. 1-octyl-3-methylimidazolium chloride ([OMIM][Cl]), 1-octyl-3-methylimidazolium dodecylsulphate ([OMIM][DS]), 1-octyl-3-methylimidazolium benzoate ([OMIM][Bz]), 1-octyl-3-methylimidazolium salicylate ([OMIM][Sc]), 1-octyl-3-methylimidazolium acetate ([OMIM][Ac]) are presented as a case study in support of the said claim. The cmcs estimated through spectrophotometric method were found to be close to the values estimated through tensiometry for the said SAILs. The cmcs for the investigated SAILS were found to vary in order of [OMIM][Cl]>[OMIM][Ac]>[OMIM][Bz]>[OMIM][Sc]>[OMIM][DS]. To the best of our knowledge the present communication will be the first report about the synthesis, characterization and micellization behaviour of [OMIM][Bz] and [OMIM][Sc]. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Storage Stability of Kinnow Fruit (Citrus reticulata) as Affected by CMC and Guar Gum-Based Silver Nanoparticle Coatings.

    Science.gov (United States)

    Shah, Syed Wasim Ahmad; Jahangir, Muhammad; Qaisar, Muhammad; Khan, Sher Aslam; Mahmood, Talat; Saeed, Muhammad; Farid, Abid; Liaquat, Muhammad

    2015-12-18

    The influence of carboxy methyl cellulose (CMC) and guargum-based coatings containing silver nanoparticles was studied on the postharvest storage stability of the kinnow mandarin (Citrus reticulata cv. Blanco) for a period of 120 days (85%-90% relative humidity) at 4 °C and 10 °C. Physicochemical and microbiological qualities were monitored after every 15 days of storage. Overall results revealed an increase in total soluble solid (TSS), total sugars, reducing sugars and weight loss but this increase was comparatively less significant in coated fruits stored at 4 °C. Ascorbic acid, total phenolics, and antioxidant activity was significantly enhanced in coated fruits stored at 4 °C. Titratable acidity significantly decreased during storage except for coated kinnow stored at 4 °C. In control samples stored at 10 °C, high intensity of fruit rotting and no chilling injury was observed. Total aerobic psychrotrophic bacteria and yeast and molds were noticed in all treatments during storage but the growth was not significant in coated fruits at 4 °C. Kinnow fruit can be kept in good quality after coating for four months at 4 °C and for 2 months at 10 °C.

  4. Storage Stability of Kinnow Fruit (Citrus reticulata as Affected by CMC and Guar Gum-Based Silver Nanoparticle Coatings

    Directory of Open Access Journals (Sweden)

    Syed Wasim Ahmad Shah

    2015-12-01

    Full Text Available The influence of carboxy methyl cellulose (CMC and guargum-based coatings containing silver nanoparticles was studied on the postharvest storage stability of the kinnow mandarin (Citrus reticulata cv. Blanco for a period of 120 days (85%–90% relative humidity at 4 °C and 10 °C. Physicochemical and microbiological qualities were monitored after every 15 days of storage. Overall results revealed an increase in total soluble solid (TSS, total sugars, reducing sugars and weight loss but this increase was comparatively less significant in coated fruits stored at 4 °C. Ascorbic acid, total phenolics, and antioxidant activity was significantly enhanced in coated fruits stored at 4 °C. Titratable acidity significantly decreased during storage except for coated kinnow stored at 4 °C. In control samples stored at 10 °C, high intensity of fruit rotting and no chilling injury was observed. Total aerobic psychrotrophic bacteria and yeast and molds were noticed in all treatments during storage but the growth was not significant in coated fruits at 4 °C. Kinnow fruit can be kept in good quality after coating for four months at 4 °C and for 2 months at 10 °C.

  5. An Investigation of Reliability Models for Ceramic Matrix Composites and their Implementation into Finite Element Codes

    Science.gov (United States)

    Duffy, Stephen F.

    1998-01-01

    The development of modeling approaches for the failure analysis of ceramic-based material systems used in high temperature environments was the primary objective of this research effort. These materials have the potential to support many key engineering technologies related to the design of aeropropulsion systems. Monolithic ceramics exhibit a number of useful properties such as retention of strength at high temperatures, chemical inertness, and low density. However, the use of monolithic ceramics has been limited by their inherent brittleness and a large variation in strength. This behavior has motivated material scientists to reinforce the monolithic material with a ceramic fiber. The addition of a second ceramic phase with an optimized interface increases toughness and marginally increases strength. The primary purpose of the fiber is to arrest crack growth, not to increase strength. The material systems of interest in this research effort were laminated ceramic matrix composites, as well as two- and three- dimensional fabric reinforced ceramic composites. These emerging composite systems can compete with metals in many demanding applications. However, the ongoing metamorphosis of ceramic composite material systems, and the lack of standardized design data has in the past tended to minimize research efforts related to structural analysis. Many structural components fabricated from ceramic matrix composites (CMC) have been designed by "trial and error." The justification for this approach lies in the fact that during the initial developmental phases for a material system fabrication issues are paramount. Emphasis is placed on demonstrating feasibility rather than fully understanding the processes controlling mechanical behavior. This is understandable during periods of rapid improvements in material properties for any composite system. But to avoid the ad hoc approach, the analytical methods developed under this effort can be used to develop rational structural

  6. Thermal Insulation System for Non-Vacuum Applications Including a Multilayer Composite

    Science.gov (United States)

    Fesmire, James E. (Inventor)

    2017-01-01

    The thermal insulation system of the present invention is for non-vacuum applications and is specifically tailored to the ambient pressure environment with any level of humidity or moisture. The thermal insulation system includes a multilayered composite including i) at least one thermal insulation layer and at least one compressible barrier layer provided as alternating, successive layers, and ii) at least one reflective film provided on at least one surface of the thermal insulation layer and/or said compressible barrier layer. The different layers and materials and their combinations are designed to provide low effective thermal conductivity for the system by managing all modes of heat transfer. The thermal insulation system includes an optional outer casing surrounding the multilayered composite. The thermal insulation system is particularly suited for use in any sub-ambient temperature environment where moisture or its adverse effects are a concern. The thermal insulation system provides physical resilience against damaging mechanical effects including compression, flexure, impact, vibration, and thermal expansion/contraction.

  7. Carbon-Carbon Composites as Recuperator Material for Direct Gas Brayton Systems

    Energy Technology Data Exchange (ETDEWEB)

    RA Wolf

    2006-07-19

    Of the numerous energy conversion options available for a space nuclear power plant (SNPP), one that shows promise in attaining reliable operation and high efficiency is the direct gas Brayton (GB) system. In order to increase efficiency, the GB system incorporates a recuperator that accounts for nearly half the weight of the energy conversion system (ECS). Therefore, development of a recuperator that is lighter and provides better performance than current heat exchangers could prove to be advantageous. The feasibility of a carbon-carbon (C/C) composite recuperator core has been assessed and a mass savings of 60% and volume penalty of 20% were projected. The excellent thermal properties, high-temperature capabilities, and low density of carbon-carbon materials make them attractive in the GB system, but development issues such as material compatibility with other structural materials in the system, such as refractory metals and superalloys, permeability, corrosion, joining, and fabrication must be addressed.

  8. Comparative evaluation of effect of different polishing systems on surface roughness of composite resin: An in vitro study.

    Science.gov (United States)

    Chour, Rashmi G; Moda, Aman; Arora, Arpana; Arafath, Muhmmed Y; Shetty, Vikram K; Rishal, Yousef

    2016-08-01

    Satisfactory composite restoration depends upon its smooth finish, quality of polishing agents, type of composite material used, and its composition. The present study evaluated the effect of different polishing systems on the surface roughness of composite resin. Forty discs of composite were prepared and equally subjected to different finishing and polishing procedures; (i) unpolished control group, (ii) sof-lex discs, (iii) diamond tips, and (iv) Astrobrush groups. Later, the surface roughness for the entire specimen was evaluated using Profilomotor. Data were tabulated and statistically analyzed using analysis of variance and Tukey's test at significance level of 0.001. Composite surface roughness after polishing was statistically significant between the groups. Sof-lex group produced lesser surface roughness compared to control, Astrobrush, and diamond group. The present study indicated that diamond tips can be used to remove rough surface whereas sof-lex can be used for final finish and polish of the composite restoration.

  9. Evaluation of surface roughness of three different composite resins with three different polishing systems.

    Science.gov (United States)

    Abzal, Mohammed S; Rathakrishnan, Mensudar; Prakash, Venkatachalam; Vivekanandhan, Paramasivam; Subbiya, Arunajatesan; Sukumaran, Vridhachalam Ganapathy

    2016-01-01

    The aim of this study was to evaluate the surface roughness of three composites with three different polishing systems. Composite specimens were made from the Teflon mold with a standardized cavity size (6 mm diameter and 3 mm height). Group I - Filtek Z350XT (Nano clusters), group II - T-Econom plus (Microhybrid), group III - G-aenial Flo (True Nano). The samples were cured for 30 s from both sides with the matrices in place. The 60 samples were divided into 3 groups (N = 20), which accounted for 40 surfaces, (n = 20 × 2 = 40) in each groups. Each group were subdivided into four subgroups based on the type polishing material, subgroup A - Control, subgroup B - Astrobrush, subgroup C - Astropol, and subgroup D - Soflex spiral wheel. The samples of all groups except group A (control) were finished and polished according to the manufacture's instruction. After polishing, the roughness (Ra) of the resin composite of all the specimens were measured using a profilometer. Soflex spiral wheel (group D) significantly had the least roughness (Ra) value as compared to the other groups. Among the three resin composites tested, G-aenial Flo exhibited least Ra value due to its reduced filler size and its uniform distribution.

  10. Selective confinement of vibrations in composite systems with alternate quasi-regular sequences

    Energy Technology Data Exchange (ETDEWEB)

    Montalban, A. [Departamento de Ciencia y Tecnologia de Materiales, Division de Optica, Universidad Miguel Hernandez, 03202 Elche (Spain); Velasco, V.R. [Instituto de Ciencia de Materiales de Madrid, CSIC, Sor Juana Ines de la Cruz 3, 28049 Madrid (Spain)]. E-mail: vrvr@icmm.csic.es; Tutor, J. [Departamento de Fisica Aplicada, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Fernandez-Velicia, F.J. [Departamento de Fisica de los Materiales, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28080 Madrid (Spain)

    2007-01-01

    We have studied the atom displacements and the vibrational frequencies of 1D systems formed by combinations of Fibonacci, Thue-Morse and Rudin-Shapiro quasi-regular stacks and their alternate ones. The materials are described by nearest-neighbor force constants and the corresponding atom masses, particularized to the Al, Ag systems. These structures exhibit differences in the frequency spectrum as compared to the original simple quasi-regular generations but the most important feature is the presence of separate confinement of the atom displacements in one of the sequences forming the total composite structure for different frequency ranges.

  11. Acrylic-phosphate glasses composites as self-curing controlled delivery systems of antibiotics.

    Science.gov (United States)

    Fernández, M; Méndez, J A; Vázquez, B; San Román, J; Ginebra, M P; Gil, F J; Manero, J M; Planell, J A

    2002-12-01

    New antibiotic delivery systems based on self-hardening methyl methacrylate (MMA)/polymethyl methacrylate (PMMA) systems and phosphate glasses (PG) in the system P(2)O(5)-CaO-Na(2)O have been developed. Self-curing formulations were prepared by mixing the solid component containing PMMA beads, different proportions of PG (30-70 wt %) and vancomycin (5 wt %) as antibiotic, with the liquid component made of MMA monomer. Dough and setting times increased with the content of PG but peak temperature decreased to values well below to guarantee the chemical stability of the antibiotic drug, gentamicin or vancomycin. Mechanical properties of the PMMA/PG composites were evaluated in compression test giving rise to values of compressive strength in the range of 100 MPa. The release of vancomycin was analyzed in vitro by immersion of samples in phosphate buffer of pH=7.4. Release profiles were influenced by the content of PG present in the cement. An initial burst of drug release was observed in all cases. The composites with 70 wt % PG released nearly the total amount of drug loaded in a period of 45 days, and those containing 60 wt % PG released the 70% of the vancomycin in the same period of time. However, either the control of the composite with 30 wt % PG released only the 30% of the drug in 10-15 days. The surface of the drug-loaded composites before and after release experiments was analyzed by ESEM. The deposition of some aggregates at certain points of the surface was detected for the specimens immersed in buffer phosphate after 45 days. This material was characterized by FTIR and Raman spectroscopy as an amorphous phosphate formed by calcium ortho and pyrophosphates, and indicates an interaction between the hydrated layer at the place of the glass and the surrounding medium.

  12. Housing Systems Influence Gut Microbiota Composition of Sows but Not of Their Piglets.

    Science.gov (United States)

    Kubasova, Tereza; Davidova-Gerzova, Lenka; Merlot, Elodie; Medvecky, Matej; Polansky, Ondrej; Gardan-Salmon, Delphine; Quesnel, Helene; Rychlik, Ivan

    2017-01-01

    Different housing systems can be used in pig production and little is known about their effect on gut microbiota composition. In this study we characterized fecal microbiota by sequencing the rRNA genes in sows kept during gestation in conventional pens with a slatted floor and in enriched pens with a floor covered with deep straw. After farrowing, microbiota of 1- and 4-day-old piglets were also monitored. Microbiota of sows from the enriched system contained significantly more Prevotella, Parabacteroides, CF231, Phascolarctobacterium, Fibrobacter, Anaerovibrio and YRC22 and significantly less Lactobacillus, Bulleidia, Lachnospira, Dorea, Ruminococcus and Oscillospira than microbiota of sows from the conventional system. The Firmicutes to Bacteroidetes ratio was 0.96 in the microbiota of sows kept in the enriched pens and this increased to 1.66 in the microbiota of sows kept in the conventional system. The production system therefore influenced microbiota composition, most likely due the ingestion of the straw. The microbiota of 1- and 4-day-old piglets differed from the microbiota of sows and sows therefore did not represent the most important source for their colonization in early days of life.

  13. Development of a New Support System for English Composition and its Performance Evaluation for International Communication

    Directory of Open Access Journals (Sweden)

    Hiroki Matsuyama

    2016-12-01

    Full Text Available English proficiency has become essential for Japanese people in today's globalized society. However, since the structure of the Japanese language is very different from that of English, it has proven difficult for Japanese people to create natural and fluent English sentences without specialized training. We developed a support system for English composition using a new method which addresses this issue. The main characteristic of the system is the use of a dictionary of similar sentence patterns. This dictionary was developed by defining a new distance measurement between sentences that emphasize expressions at the end of a sentence in a Japanese text due to the head finality of Japanese. Our experiment revealed that in terms of fluency of translation, higher scores were obtained with this system, in comparison with the singular use of a word dictionary. Also, in terms of both adequacy and fluency, the average values with this system exceeded those with traditional support systems for English composition considered in this study.

  14. Randomized Clinical Trial of Composite Restorations in Primary Teeth: Effect of Adhesive System after Three Years

    Directory of Open Access Journals (Sweden)

    Secil Bektaş Donmez

    2016-01-01

    Full Text Available The purpose of this study was to assess the clinical performance of composite restorations placed with different adhesive systems in primary teeth. In 32 patients, 128 composite restorations were placed using a split-mouth design as follows (4 groups/patient: three-step etch-and-rinse (Group 1, two-step etch-and-rinse (Group 2, two-step self-etch (Group 3, and one-step self-etch (Group 4. The restorations were clinically evaluated at baseline and at 6, 18, and 36 months according to the FDI criteria. There was no significant difference between the adhesive systems in retention of the restorations (p>0.05. Over time, there was a statistically significant decrease in marginal adaptation in all groups, whereas surface and marginal staining significantly increased in Groups 3 and 4 (p<0.05. The etch-and-rinse adhesive systems resulted in better marginal adaptation than the self-etch adhesive systems (p<0.05. It was concluded that preetching of the primary enamel might help improve the clinical performance of the self-etch adhesive systems in primary teeth.

  15. EMTA’s Evaluation of the Elastic Properties for Fiber Polymer Composites Potentially Used in Hydropower Systems

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ba Nghiep; Paquette, Joshua

    2010-08-01

    Fiber-reinforced polymer composites can offer important advantages over metals where lightweight, cost-effective manufacturing and high mechanical performance can be achieved. To date, these materials have not been used in hydropower systems. In view of the possibility to tailor their mechanical properties to specific applications, they now have become a subject of research for potential use in hydropower systems. The first step in any structural design that uses composite materials consists of evaluating the basic composite mechanical properties as a function of the as-formed composite microstructure. These basic properties are the elastic stiffness, stress-strain response, and strength. This report describes the evaluation of the elastic stiffness for a series of common discontinuous fiber polymer composites processed by injection molding and compression molding in order to preliminarily estimate whether these composites could be used in hydropower systems for load-carrying components such as turbine blades. To this end, the EMTA (Copyright © Battelle 2010) predictive modeling tool developed at the Pacific Northwest National Laboratory (PNNL) has been applied to predict the elastic properties of these composites as a function of three key microstructural parameters: fiber volume fraction, fiber orientation distribution, and fiber length distribution. These parameters strongly control the composite mechanical performance and can be tailored to achieve property enhancement. EMTA uses the standard and enhanced Mori-Tanaka type models combined with the Eshelby equivalent inclusion method to predict the thermoelastic properties of the composite based on its microstructure.

  16. Nondestructive inspection of aerospace composites by a fiber-coupled laser ultrasonics system

    Science.gov (United States)

    Vandenrijt, J.-F.; Languy, F.; Thizy, C.; Georges, M. P.

    2017-06-01

    Laser ultrasonics is a technique currently studied for nondestructive inspection of aerospace composite structures based on carbon fibers. It combines a pulsed laser impacting the surface generates an ultrasound inside the material, through the nondestructive thermoelastic effect. Second a detection interferometer probes the impacted point in order to measure the displacement of the surface resulting from the emitted ultrasound wave and the echo coming back from the different interfaces of the structure. Laser ultrasonics is of interest for inspecting complex shaped composites. We have studied the possibility of using frequency doubled YAG laser for the generation and which is fiber-coupled, together with a fibercoupled interferometric probe using a YAG laser in the NIR. Our final system is a lightweight probe attached to a robot arm and which is able to scan complex shapes. The performances of the system are compared for different wavelengths of generations. Also we have studied some experimental parameters of interest such as tolerance to angle and focus distance, and different geometries of generation beams. We show some examples of inspection of reference parts with known defects. In particular C-scans of curved composites structures are presented.

  17. Application of Technogenic-Raw Material and Burning Out Additive in Composite Ceramic System

    Directory of Open Access Journals (Sweden)

    Olga KIZINIEVIČ

    2012-09-01

    Full Text Available The investigation of the composite ceramic system containing easily fusible hydro-micous clay, technogenic finely dispersed raw material, and burning out waste additive is presented in the article. The properties of the raw materials used are described in the paper. The obtained ceramic bodies were burned at 1000 °C and 1050 °C temperatures, keeping at the highest burning temperature for 4 h. The analysis of physical-mechanical properties of composite ceramics (density, compressive strength, water absorption, its structural parameters (effective and total open porosity, reserve of pore volume, relative wall thickness of the pores and capillaries, and X-ray diffraction analysis was performed. The interdependencies between some structural parameters are described by empirical equations. DOI: http://dx.doi.org/10.5755/j01.ms.18.3.2443

  18. Determination of gas composition in a biogas plant using a Raman-based sensor system

    Science.gov (United States)

    Eichmann, S. C.; Kiefer, J.; Benz, J.; Kempf, T.; Leipertz, A.; Seeger, T.

    2014-07-01

    We propose a gas sensor, based on spontaneous Raman scattering, for the compositional analysis of typical biogas mixtures and present a description of the sensor, as well as of the calibration procedure, which allows the quantification of condensable gases. Moreover, we carry out a comprehensive characterization of the system, in order to determine the measurement uncertainty, as well as influences of temperature and pressure fluctuation. Finally, the sensor is applied at different locations inside a plant in which biogas is produced from renewable raw materials. The composition is monitored after fermenting, after purification and after the final conditioning, where natural gas is added. The Raman sensor is able to detect all the relevant gas components, i.e. CH4, CO2, N2 and H2O, and report their individual concentrations over time. The results were compared to reference data from a conventional gas analyzer and good agreement was obtained.

  19. Walker Branch Throughfall Displacement Experiment Data Report: Site Characterization, System Performance, Weather, Species Composition, and Growth

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, P.J.

    2001-09-04

    This numeric data package provides data sets, and accompanying documentation, on site characterization, system performance, weather, species composition, and growth for the Throughfall Displacement Experiment, which was established in the Walker Branch Watershed of East Tennessee to provide data on the responses of forests to altered precipitation regimes. The specific data sets include soil water content and potential, coarse fraction of the soil profile, litter layer temperature, soil temperature, monthly weather, daily weather, hourly weather, species composition of trees and saplings, mature tree and sapling annual growth, and relative leaf area index. Fortran and SAS{trademark} access codes are provided to read the ASCII data files. The data files and this documentation are available without charge on a variety of media and via the Internet from the Carbon Dioxide Information Analysis Center (CDIAC).

  20. High-Confidence Compositional Reliability Assessment of SOA-Based Systems Using Machine Learning Techniques

    Science.gov (United States)

    Challagulla, Venkata U. B.; Bastani, Farokh B.; Yen, I.-Ling

    Service-oriented architecture (SOA) techniques are being increasingly used for developing critical applications, especially network-centric systems. While the SOA paradigm provides flexibility and agility to better respond to changing business requirements, the task of assessing the reliability of SOA-based systems is quite challenging. Deriving high confidence reliability estimates for mission-critical systems can require huge costs and time. SOAsystems/ applications are built by using either atomic or composite services as building blocks. These services are generally assumed to be realized with reuse and logical composition of components. One approach for assessing the reliability of SOA-based systems is to use AI reasoning techniques on dynamically collected failure data of each service and its components as one of the evidences together with results from random testing. Memory-Based Reasoning technique and Bayesian Belief Net-works are verified as the reasoning tools best suited to guide the prediction analysis. A framework constructed from the above approach identifies the least tested and “high usage” input subdomains of the service(s) and performs necessary remedial actions depending on the predicted results.

  1. Composite Bonding to Stainless Steel Crowns Using a New Universal Bonding and Single-Bottle Systems

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Hattan

    2013-01-01

    Full Text Available Aim. The aim of this study is to evaluate the shear bond strength of nanocomposite to stainless steel crowns using a new universal bonding system. Material and Methods. Eighty (80 stainless steel crowns (SSCs were divided into four groups (20 each. Packable nanocomposite was bonded to the lingual surface of the crowns in the following methods: Group A without adhesive (control group, Group B using a new universal adhesive system (Scotchbond Universal Adhesive, 3M ESPE, Seefeld, Germany, and Group C and Group D using two different brands of single-bottle adhesive systems. Shear bond strengths were calculated and the types of failure also were recorded. Results. The shear strength of Group B was significantly greater than that of other groups. No significant differences were found between the shear bond strengths of Groups C and D. The control group had significantly lower shear bond strength ( to composite than the groups that utilized bonding agents. Conclusion. Composites bonding to stainless steel crowns using the new universal bonding agent (Scotchbond Universal Adhesive, 3M ESPE, Seefeld, Germany show significantly greater shear bond strengths and fewer adhesive failures when compared to traditional single-bottle systems.

  2. CNT reinforced epoxy foamed and electrospun nano-fiber interlayer systems for manufacturing lighter and stronger featherweight(TM) composites

    Science.gov (United States)

    Drakonakis, Vasileios M.

    Multiple works have been performed in improving carbon fiber reinforced polymer (CFRP) composites especially in terms of strength so delamination, which is the major defect in laminated composites, is prevented. Nevertheless, there is not much focus on improving conventional CFRP systems in terms of weight especially when these are used in primary structures. This work questions whether lighter and at the same time stronger CFRP composites can be manufactured in order to replace conventional CFRP systems in major applications. Under this perspective, this study demonstrates that inducing controlled porosity may offer a systemic approach for manufacturing light weight carbon fiber reinforced polymer (CFRP) matrix composites. Additionally, towards this scope, this work has focused on analyzing and describing the related matrix systems utilizing mostly classic viscoelastic theory. An in-depth characterization of the thermosetting matrix systems viscoelasticity kinetics as well as of the impregnation process towards its improvement in terms of lower cost is explored. Overall, this work makes an effort to establish the fundamentals for creating the next generation of light weight structural composites, the featherweight composites, by introducing porosity through several controlled reinforcements in a systemic and reproducible manner at the macro- micro- and nano- scales in the interlayer. By extensively describing the matrix system and the manufacturing processes and focusing on analytically testing the interlayer reinforcement systems, it is expected that featherweight CFRP will achieve lighter weight and at the same time higher mechanical properties.

  3. Scanning Ultrasonic Spectroscopy System Developed for the Inspection of Composite Flywheels

    Science.gov (United States)

    Martin, Richard E.; Baaklini, George Y.

    2002-01-01

    Composite flywheels are being considered as replacements for chemical batteries aboard the International Space Station. A flywheel stores energy in a spinning mass that can turn a generator to meet power demands. Because of the high rotational speeds of the spinning mass, extensive testing of the flywheel system must be performed prior to flight certification. With this goal in mind, a new scanning system has been developed at the NASA Glenn Research Center for the nondestructive inspection of composite flywheels and flywheel subcomponents. The system uses ultrasonic waves to excite a material and examines the response to detect and locate flaws and material variations. The ultrasonic spectroscopy system uses a transducer to send swept-frequency ultrasonic waves into a test material and then receives the returning signal with a second transducer. The received signal is then analyzed in the frequency domain using a fast Fourier transform. A second fast Fourier transform is performed to examine the spacing of the peaks in the frequency domain. The spacing of the peaks is related to the standing wave resonances that are present in the material because of the constructive and destructive interferences of the waves in the full material thickness as well as in individual layers within the material. Material variations and flaws are then identified by changes in the amplitudes and positions of the peaks in both the frequency and resonance spacing domains. This work, conducted under a grant through the Cleveland State University, extends the capabilities of an existing point-by-point ultrasonic spectroscopy system, thus allowing full-field automated inspection. Results of an ultrasonic spectroscopy scan of a plastic cylinder with intentionally seeded flaws. The result of an ultrasonic spectroscopy scan of a plastic cylinder used as a proof-of-concept specimen is shown. The cylinder contains a number of flat bottomed holes of various sizes and shapes. The scanning system

  4. Thermo-kinematic evolution of the Annapurna-Dhaulagiri Himalaya, central Nepal: The Composite Orogenic System

    Science.gov (United States)

    Parsons, A. J.; Law, R. D.; Lloyd, G. E.; Phillips, R. J.; Searle, M. P.

    2016-04-01

    The Himalayan orogen represents a "Composite Orogenic System" in which channel flow, wedge extrusion, and thrust stacking operate in separate "Orogenic Domains" with distinct rheologies and crustal positions. We analyze 104 samples from the metamorphic core (Greater Himalayan Sequence, GHS) and bounding units of the Annapurna-Dhaulagiri Himalaya, central Nepal. Optical microscopy and electron backscatter diffraction (EBSD) analyses provide a record of deformation microstructures and an indication of active crystal slip systems, strain geometries, and deformation temperatures. These data, combined with existing thermobarometry and geochronology data are used to construct detailed deformation temperature profiles for the GHS. The profiles define a three-stage thermokinematic evolution from midcrustal channel flow (Stage 1, >700°C to 550-650°C), to rigid wedge extrusion (Stage 2, 400-600°C) and duplexing (Stage 3, migration of the GHS through these Orogenic Domains and reflects the spatial and temporal variability in rheological boundary conditions that govern orogenic systems.

  5. Influence of 10-MDP Adhesive System on Shear Bond Strength of Zirconia-Composite Interfaces

    Directory of Open Access Journals (Sweden)

    Philipp Cornelius Pott

    2015-09-01

    Full Text Available Introduction: This in-vitro study investigated the initial 24h bond strength between different composites and zirconia after application of four different adhesive systems. Methods: A total of 120 specimens of zirconia (InCoris, Sirona, Germany, Bernsheim were ground with a 165 µm grit rotating diamond disc. Thirty specimens were each additionally treated with Cimara Zircon “CZ” (VOCO GmbH, Germany, Cuxhaven, Futurabond U “FBU” (VOCO GmbH, Futurabond M+ “FBM” (VOCO GmbH or Futurabond M+ in combination with the DCA activator “FBMD” (VOCO GmbH. One of three different types of composites – BifixSE (“BS”, BifixQM (“BQ” or GrandioSO (“G” (VOCO GmbH – was bonded to ten specimens each in every group. Shear bond strength (SBS was determined in a universal testing machine. Statistical analysis was performed with ANOVA and the Tukey test. Results: FBM and FBMD gave higher SBS than CZ and FBU in combination with all tested composites. In comparison to FBU, FBM gave statistically significant increases in SBS with BifixSE (19.4±5.7 MPa (P

  6. Decreasing vitamin premix on chicken carcass composition and blood chemistry in floor and battery cage systems

    Directory of Open Access Journals (Sweden)

    Mahmood Shivazad

    2012-01-01

    Full Text Available Two experiments were conducted the to compare the effect of a decreasing amount of vitamin premix in diets inbroilers from 29 to 42 days of age on carcass composition and blood chemistry in floor (Experiment 1 and battery cage (Experiment 2 systems. At 35 and 42 days of ages, one bird of each replicate was slaughtered and carcass composition was measured. Blood concentrations of alkaline phosphatase (ALP and Ca were used to diagnose vitamin D3 deficiency and enzymes aspartate amino transferase (AST to identify vitamin E deficiency. Floor raised birds showed that vitamin premix reduction/withdrawal at 29 days of age did not impair body weight (BW, carcass composition, ALP and Ca during the final rearing period. However, diet without vitamin premix (T1 had a higher AST at 42 days of age than the other diets. Birds reared in cages were slightly more sensitive to vitamin premix reduction/withdrawal, probably due to the impracticality of performing coprophagy. Diet without vitamin premix (T1 had a lower BW, carcass breast and thigh yield at 42 days of age; also serum ALP, AST and Ca were impaired. In conclusion, the withdrawal of vitamins is not a reasonable option but it is possible to reduce vitamin premix in finisher broilers’ diets without negative effects on performance and on some metabolic traits during the finisher period with both methods of rearing.

  7. Attribute Reduction Algorithm Based on Structure Discernibility Matrix in Composite Information Systems

    Directory of Open Access Journals (Sweden)

    Ge Mei-Jun

    2017-01-01

    Full Text Available Attribute reduction, as an important preprocessing step for knowledge acquiring in data mining, is one of the key issues in rough set theory. It can only deal with attributes of a specific type in the information system by using a specific binary relation. However, there may be attributes of multiple different types in information systems in real-life applications. A composite relation is proposed to process attributes of multiple different types simultaneously in composite information systems. In order to solve the time-consuming problem of traditional heuristic attribute reduction algorithms, a novel attribute reduction algorithm based on structure discernibility matrix was proposed in this paper. The proposed algorithms can choose the same attribute reduction as its previous version, but it can be used to accelerate a heuristic process of attribute reduction by avoiding the process of intersection and adopting the forward greedy attribute reduction approach. The theoretical analysis and experimental results with UCI data sets show that the proposed algorithm can accelerate the heuristic process of attribute reduction.

  8. Measurement of the optical density of packable composites: comparison between direct and indirect digital systems

    Directory of Open Access Journals (Sweden)

    Graziottin Luiz Felipe Rodrigues

    2002-01-01

    Full Text Available The aim of this study was to measure the optical density of four packable composite resins with widths of 1, 2, 3 and 4 mm, by means of Digora® (direct and DentScan DentView® (indirect digital imaging systems, in order to compare both methods. Twenty acrylic plates, with the proposed thicknesses, were used, each one containing a sample of each resin. Each acrylic plate was radiographed three times, under a standardized technique. For the Digora® system, an optical plate was used under each resin sample, and, for the DentScan DentView® system, occlusal films were employed, totalizing 60 exposures for each system. Optical plates and films were scanned and three consecutive optical readouts were carried out, totalizing 1,440 readouts. The results were submitted to statistical analysis and revealed that the average optical density of the four resins always increased as thickness increased. Regarding the comparisons between the composite resins, in both analysis the resin with the greater optical density was SurefilTM followed by ProdigyTM Condensable, AlertTM and Solitaire®. The correlations between the results of Digora® and DentScan DentView® were significant for the different thicknesses and materials. The observed tendency is that as the values obtained with the Digora® system increase, so do the values obtained with DentScan DentView®. While thickness increased, the values of optical density in both Digora® and DentScan DentView® tended to approach each other. The Digora® system presented smaller amplitude between the results obtained in adjacent thicknesses.

  9. Fatty acid and vitamin E composition of intramuscular fat in cattle reared in different production systems.

    Science.gov (United States)

    De la Fuente, J; Díaz, M T; Alvarez, I; Oliver, M A; Font I Furnols, M; Sañudo, C; Campo, M M; Montossi, F; Nute, G R; Cañeque, V

    2009-07-01

    The aim of this study was to evaluate the fatty acid composition of intramuscular fat and the vitamin E content of beef from different production systems. Four cattle production systems were used: cattle reared under intensive conditions and fed concentrate (INT1) from Spain, cattle raised at pasture and supplemented with concentrate (SUP1) from the United Kingdom, cattle raised at pasture and on corn silage (SUP2) from Germany and cattle reared under extensive conditions slaughtered at two and three years old (EXT2 and EXT3) from Uruguay. The highest proportion and content (mg per 100g of muscle) of linoleic acid (C18:2n-6) and arachidonic acid (C20:4n-6) and the lowest saturated fatty acids (SFA) was found in INT1 beef. In contrast, beef reared under extensive conditions showed the highest proportion and content of linolenic acid (C18:3n-3), docosapentaenoic acid (DPA, C22:5n-3) and eicosapentaenoic acid (EPA, C20:5n-3), and SUP1 and SUP2 beef showed the highest level of palmitic acid (C16:0) and SFA. Beef from intensive system (INT1) had the lowest P/S (PUFA/SFA) ratio, whereas beef from extensive system (EXT2 and EXT3) had the lowest n-6/n-3 ratio. The results of the PCA (principal components analysis) of fatty acid composition showed that beef from intensive system (INT1) was clearly differentiated from the other meats and was located with the C18:2n-6 and C20:4n-6 and the n-6/n-3 ratio. EXT2 and EXT3 beef were located with C18:3n-3 and long chain fatty acids. Beef from extensive systems had the highest concentration of vitamin E (3.91mg α-tocopherol/kg muscle).

  10. Preparation and characterization of silver nanoparticles on silk fibroin/carboxymethylchitosan composite sponge as anti-bacterial wound dressing.

    Science.gov (United States)

    Pei, Zejun; Sun, Qing; Sun, Xin; Wang, Yaping; Zhao, Peng

    2015-01-01

    The infection in burn wounds covered by biologic dressings leads to wound deepening and chronic wounds. The introduction of silver nanoparticles (AgNPs) into biologic dressings is a beneficial method to prevent wound infection and simultaneously promote wound healing. In this study, an AgNP-loaded silk fibroin (SF)/carboxymethylchitosan (CMC) composite sponge was fabricated. AgNPs with a mean diameter of 4.9 nm was synthesized in SF solution in situ. While CMC was incorporated and chemically crosslinked, SF was insolubilized by ethanol annealing. SEM imaging determined that the AgNP-loaded SF/CMC sponge was more porous than the pure SF sponge. Anti-bacterial results, measured by disk-diffusion and bacterial suspension assay, showed that the AgNP-loaded SF/CMC sponge demonstrated effective anti-bacterial activity against S. aureus and P. aeruginosa, and that its anti-P. aeruginosa activity was higher than that of AQUACEL®; Ag. The introduction of CMC improved the water absorption capacity, retention ability, and water vapor transmission rate of the sponge, which are all important properties of wound dressings.

  11. Methods for the selective detection of alkyne-presenting molecules and related compositions and systems

    Energy Technology Data Exchange (ETDEWEB)

    Valdez, Carlos A.; Vu, Alexander K.

    2017-10-17

    Provided herein are methods for selectively detecting an alkyne-presenting molecule in a sample and related detection reagents, compositions, methods and systems. The methods include contacting a detection reagent with the sample for a time and under a condition to allow binding of the detection reagent to the one or more alkyne-presenting molecules possibly present in the matrix to the detection reagent. The detection reagent includes an organic label moiety presenting an azide group. The binding of the azide group to the alkyne-presenting molecules results in emission of a signal from the organic label moiety.

  12. Verification of Large State/Event Systems using Compositionality and Dependency Analysis

    DEFF Research Database (Denmark)

    Lind-Nielsen, Jørn; Andersen, Henrik Reif; Hulgaard, Henrik

    2001-01-01

    A state/event model is a concurrent version of Mealy machines used for describing embedded reactive systems. This paper introduces a technique that uses compositionality and dependency analysis to significantly improve the efficiency of symbolic model checking of state/event models. It makes poss...... possible automated verification of large industrial designs with the use of only modest resources (less than 5 minutes on a standard PC for a model with 1421 concurrent machines). The results of the paper are being implemented in the next version of the commercial tool visualSTATETM....

  13. Adhesive systems: important aspects related to their composition and clinical use

    Directory of Open Access Journals (Sweden)

    Mario Honorato Silva e Souza Junior

    2010-06-01

    Full Text Available This literature review article addresses the types and the main components of different etch-and-rinse and self-etch adhesive systems available in the market, and relates them to their function, possible chemical interactions and infuence of handling characteristics. Scanning electron microscopy (SEM images are presented to characterize the interface between adhesives and dentin. Adhesive systems have been recently classifed according to their adhesion approaches in etch-and-rinse, self-etch and glass ionomer. The etch-and-rinse systems require a specifc acid-etch procedure and may be performed in two or three steps. Self-etch systems employ acidic monomers that demineralize and impregnate dental substrates almost at the same time. These systems are separated in one or two steps. Some advantages and defciencies were noted for etch-and-rinse and self-etch approaches, mainly for the simplifed ones due to some chemical associations and interactions. The SEM micrographs illustrate different relationships between adhesive systems and dental structures, particularly dentin. The knowledge of composition, characteristics and mechanisms of adhesion of each adhesive system is of fundamental importance to permit the adoption of ideal bonding strategies under clinical conditions.

  14. Adhesive systems: important aspects related to their composition and clinical use

    Science.gov (United States)

    SILVA E SOUZA JUNIOR, Mario Honorato; CARNEIRO, Karina Gama Kato; LOBATO, Marcelo Figueiredo; SILVA E SOUZA, Patrícia de Almeida Rodrigues; de GÓES, Mário Fernando

    2010-01-01

    This literature review article addresses the types and the main components of different etch-and-rinse and self-etch adhesive systems available in the market, and relates them to their function, possible chemical interactions and influence of handling characteristics. Scanning electron microscopy (SEM) images are presented to characterize the interface between adhesives and dentin. Adhesive systems have been recently classified according to their adhesion approaches in etch-and-rinse, self-etch and glass ionomer. The etch-andrinse systems require a specific acid-etch procedure and may be performed in two or three steps. Self-etch systems employ acidic monomers that demineralize and impregnate dental substrates almost at the same time. These systems are separated in one or two steps. Some advantages and deficiencies were noted for etch-and-rinse and self-etch approaches, mainly for the simplified ones due to some chemical associations and interactions. The SeM micrographs illustrate different relationships between adhesive systems and dental structures, particularly dentin. The knowledge of composition, characteristics and mechanisms of adhesion of each adhesive system is of fundamental importance to permit the adoption of ideal bonding strategies under clinical conditions. PMID:20856995

  15. Development of structural health monitoring systems for composite bonded repairs on aircraft structures

    Science.gov (United States)

    Galea, Stephen C.; Powlesland, Ian G.; Moss, Scott D.; Konak, Michael J.; van der Velden, Stephen P.; Stade, Bryan; Baker, Alan A.

    2001-08-01

    The application of bonded composite patches to repair or reinforce defective metallic structures is becoming recognized as a very effective versatile repair procedure for many types of problems. Immediate applications of bonded patches are in the fields of repair of cracking, localized reinforcement after removal of corrosion damage and for reduction of fatigue strain. However, bonded repairs to critical components are generally limited due to certification concerns. For certification and management of repairs to critical structure, the Smart Patch approach may be an acceptable solution from the airworthiness prospective and be cost effective for the operator and may even allow some relaxation of the certification requirements. In the most basic form of the Smart Patch in-situ sensors can be used as the nerve system to monitor in service the structural condition (health or well-being) of the patch system and the status of the remaining damage in the parent structure. This application would also allow the operator to move away from current costly time-based maintenance procedures toward real-time health condition monitoring of the bonded repair and the repaired structure. TO this end a stand-alone data logger device, for the real-time health monitoring of bonded repaired systems, which is in close proximity to sensors on a repair is being developed. The instrumentation will measure, process and store sensor measurements during flight and then allow this data to be up-loaded, after the flight, onto a PC, via remote (wireless) data access. This paper describes two in-situ health monitoring systems which will be used on a composite bonded patch applied to an F/A-18. The two systems being developed consists of a piezoelectric (PVDF) film-based and a conventional electrical-resistance foil strain gauge-based sensing system. The latter system uses a primary cell (Lithium- based battery) as the power source, which should enable an operating life of 1-2 years. The patch

  16. "A New Class of Creep Resistant Oxide/Oxide Ceramic Matrix Composites"

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Mohit Jain, Dr. Ganesh Skandan, Prof. Roger Cannon, Rutgers University

    2007-03-30

    Despite recent progress in the development of SiC-SiC ceramic matrix composites (CMCs), their application in industrial gas turbines for distributed energy (DE) systems has been limited. The poor oxidation resistance of the non-oxide ceramics warrants the use of envrionmental barrier coatings (EBCs), which in turn lead to issues pertaining to life expectancy of the coatings. On the other hand, oxide/oxide CMCs are potential replacements, but their use has been limited until now due to the poor creep resistance at high temperatures, particularly above 1200 oC: the lack of a creep resistant matrix has been a major limiting factor. Using yttrium aluminum garnet (YAG) as the matrix material system, we have advanced the state-of-the-art in oxide/oxide CMCs by introducing innovations in both the structure and composition of the matrix material, thereby leading to high temperature matrix creep properties not achieved until now. An array of YAG-based powders with a unique set of particle characteristics were produced in-house and sintered to full density and compressive creep data was obtained. Aided in part by the composition and the microstructure, the creep rates were found to be two orders of magnitude smaller than the most creep resistant oxide fiber available commercially. Even after accounting for porosity and a smaller matrix grain size in a practical CMC component, the YAG-based matrix material was found to creep slower than the most creep resistant oxide fiber available commercially.

  17. The Application of Metal Matrix Composite Materials in Propulsion System Valves

    Science.gov (United States)

    Laszar, John; Shah, Sandeep; Kashalikar, Uday; Rozenoyer, Boris

    2003-01-01

    Metal Matrix Composite (MMC) materials have been developed and used in many applications to reduce the weight of components where weight and deflection are the driving design requirement. MMC materials are being developed for use in some propulsion system components, such as turbo-pumps and thrust chambers. However, to date, no propulsion system valves have been developed that take advantage of the materials unique properties. The stiffness of MMC's could help keep valves light or improve life where deflection is the design constraint (such as seal and bearing locations). The low CTE of the materials might allow the designer to reduce tolerances and clearances producing better performance and lighter weight valves. Using unique manufacturing processes allow parts to be plated/coated for longer life and allow joining either by welding or threading/bolting. Additionally, casting of multi part pre-forms to form a single part can lead to designs that would be hard or impossible to manufacture with other methods. Therefore, NASA's Marshall Space Flight Center (MSFC) has developed and tested a prototype propulsion system valve that utilizes these materials to demonstrate these advantages. Through design and testing, this effort will determine the best use of these materials in valves designed to achieve the goal of a highly reliable and lightweight propulsion system. This paper is a continuation of the paper, The Application of Metal Matrix Composite Materials In Propulsion System Valves, presented at the JANNAF Conference held in April, 2002. Fabrication techniques employed, valve development, and valve test results will be discussed in this paper.

  18. Application of the correlation consistent composite approach to biological systems and noncovalent interactions

    Science.gov (United States)

    Riojas, Amanda G.

    Advances in computing capabilities have facilitated the application of quantum mechanical methods to increasingly larger and more complex chemical systems, including weakly interacting and biologically relevant species. One such ab initio-based composite methodology, the correlation consistent composite approach (ccCA), has been shown to be reliable for the prediction of enthalpies of formation and reaction energies of main group species in the gas phase to within 1 kcal mol-1, on average, of well-established experiment, without dependence on experimental parameterization or empirical corrections. In this collection of work, ccCA has been utilized to determine the proton affinities of deoxyribonucleosides within an ONIOM framework (ONIOM-ccCA) and to predict accurate enthalpies of formation for organophosphorus compounds. Despite the complexity of these systems, ccCA is shown to result in enthalpies of formation to within ~2 kcal mol-1 of experiment and predict reliable reaction energies for systems with little to no experimental data. New applications for the ccCA method have also been introduced, expanding the utility of ccCA to solvated systems and complexes with significant noncovalent interactions. By incorporating the SMD solvation model into the ccCA formulation, the Solv-ccCA method is able to predict the pKa values of nitrogen systems to within 0.7 pKa unit (less than 1.0 kcal mol-1), overall. A hydrogen bonding constant has also been developed for use with weakly interacting dimers and small cluster compounds, resulting in ccCA interaction energies for water clusters and dimers of the S66 set to within 1.0 kcal mol-1 of well-established theoretical values.

  19. An All-Organic Composite System for Resistive Change Memory via the Self-Assembly of Plastic-Crystalline Molecules.

    Science.gov (United States)

    Cha, An-Na; Lee, Sang-A; Bae, Sukang; Lee, Sang Hyun; Lee, Dong Su; Wang, Gunuk; Kim, Tae-Wook

    2017-01-25

    An all-organic composite system was introduced as an active component for organic resistive memory applications. The active layer was prepared by mixing a highly polar plastic-crystalline organic molecule (succinonitrile, SN) into an insulating polymer (poly(methyl methacrylate), PMMA). As increasing concentrations of SN from 0 to 3.0 wt % were added to solutions of different concentrations of PMMA, we observed distinguishable microscopic surface structures on blended films of SN and PMMA at certain concentrations after the spin-casting process. The structures were organic dormant volcanos composed of micron-scale PMMA craters and disk type SN lava. Atomic force microscopy (AFM), cross-sectional transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy dispersive X-ray spectrometer (EDX) analysis showed that these structures were located in the middle of the film. Self-assembly of the plastic-crystalline molecules resulted in the phase separation of the SN:PMMA mixture during solvent evaporation. The organic craters remained at the surface after the spin-casting process, indicative of the formation of an all-organic composite film. Because one organic crater contains one SN disk, our system has a coplanar monolayer disk composite system, indicative of the simplest composite type of organic memory system. Current-voltage (I-V) characteristics of the composite films with organic craters revealed that our all-organic composite system showed unipolar type resistive switching behavior. From logarithmic I-V characteristics, we found that the current flow was governed by space charge limited current (SCLC). From these results, we believe that a plastic-crystalline molecule-polymer composite system is one of the most reliable ways to develop organic composite systems as potential candidates for the active components of organic resistive memory applications.

  20. Color stability of indirect composite materials polymerized with different polymerization systems.

    Science.gov (United States)

    Nakazawa, Motoko

    2009-06-01

    The purpose of the current study was to evaluate the color stability of two indirect composite materials (Sinfony and Pearleste) polymerized with different laboratory polymerization systems. Disk specimens were prepared with their proprietary polymerization systems (Visio and Pearlcure systems) or with a metal halide light polymerization unit (Hyper LII) for 60, 120, and 180 s. After storage at 37 degrees C for 24 h, the specimens were immersed in either purified water or tea. Color change between baseline evaluation and after 4 weeks was determined with a dental chroma meter (ShadeEye NCC) using black and white backgrounds. CIE 1976 L(*)a(*)b(*) values were determined, and they were converted into DeltaE(*)(ab) values. The DeltaE(*)(ab) value of the Sinfony material immersed in tea was the highest when the material was polymerized with the proprietary Visio system. The Pearleste material immersed in purified water and tea was not affected substantially by the polymerization systems. Among the 12 groups polymerized with the Hyper LII units, DeltaE(*)(ab) values of 11 groups were significantly lower for the Pearleste material than for the Sinfony material. It can be concluded that the Pearleste material was stable against color change when the material was polymerized with either the Pearlcure system or with the Hyper LII unit.

  1. Refueling emissions from cars in Japan: Compositions, temperature dependence and effect of vapor liquefied collection system

    Science.gov (United States)

    Yamada, Hiroyuki; Inomata, Satoshi; Tanimoto, Hiroshi

    2015-11-01

    Refueling emissions from cars available on the Japanese market, which were not equipped with specific controlling devices, were investigated. For the composition analysis, a proton transfer reaction plus switchable reagent ion mass spectrometry (PTR + SRI-MS), which is capable of real-time measurement, was used. In addition, the performance of a vapor liquefied collection system (VLCS), which is a recently developed controlling device, was evaluated and compared with an onboard refueling vapor recovery (ORVR) system. The refueling emission factor of uncontrolled vehicles at 20 °C was 1.02 ± 0.40 g/L in the case dispensing 20 L of fuel. The results of composition analysis indicated that the maximum incremental reactivity (MIR) of refueling emissions in Japan was 3.49 ± 0.83. The emissions consist of 80% alkanes and 20% alkenes, and aromatics and di-enes were negligible. C4 alkene had the highest impact on the MIR of refueling emissions. The amounts of refueling emissions were well reproduced by a function developed by MOVE2010 in the temperature range of 5-35 °C. The compositions of the refueling emissions varied in this temperature range, but the change in MIR was negligible. The trapping efficiency of VLCS was the same level as that of the ORVR (over 95%). The MIRs of refueling and evaporative emissions were strongly affected by that of the test fuel. This study and our previous study indicated that MIRbreakthrough ≈ MIRrefueling ≈ MIRfuel + 0.5 and MIRpermeation ≈ MIRfuel. The real-world estimated average MIRfuel in Japan was about 3.0.

  2. Concrete compositions and methods

    Science.gov (United States)

    Chen, Irvin; Lee, Patricia Tung; Patterson, Joshua

    2015-06-23

    Provided herein are compositions, methods, and systems for cementitious compositions containing calcium carbonate compositions and aggregate. The compositions find use in a variety of applications, including use in a variety of building materials and building applications.

  3. Structural Composites Industries 4 kilowatt wind system development. Phase I: design and analysis, technical report

    Energy Technology Data Exchange (ETDEWEB)

    Malkine, N.; Bottrell, G.; Weingart, O.

    1981-05-01

    A 4 kW small wind energy conversion system (SWECS) has been designed for residential applications in which relatively low (10 mph) mean annual wind speeds prevail. The objectives were to develop such a machine to produce electrical energy at 6 cents per kWh while operating in parallel with a utility grid or auxiliary generator. The Phase I effort began in November, 1979 and was carried through the Final Design Review in February 1981. During this period extensive trade, optimization and analytical studies were performed in an effort to provide the optimum machine to best meet the objectives. Certain components, systems and manufacturing processes were tested and evaluated and detail design drawings were produced. The resulting design is a 31-foot diameter horizontal axis downwind machine rated 5.7 kW and incorporating the following unique features: Composite Blades; Free-Standing Composite Tower; Torque-Actuated Blade Pitch Control. The design meets or exceeds all contract requirements except that for cost of energy. The target 6 cents per kWh will be achieved in a mean wind speed slightly below 12 mph instead of the specified 10 mph.

  4. An Evaluation of the Pea Pod System for Assessing Body Composition of Moderately Premature Infants

    Directory of Open Access Journals (Sweden)

    Elisabet Forsum

    2016-04-01

    Full Text Available (1 Background: Assessing the quality of growth in premature infants is important in order to be able to provide them with optimal nutrition. The Pea Pod device, based on air displacement plethysmography, is able to assess body composition of infants. However, this method has not been sufficiently evaluated in premature infants; (2 Methods: In 14 infants in an age range of 3–7 days, born after 32–35 completed weeks of gestation, body weight, body volume, fat-free mass density (predicted by the Pea Pod software, and total body water (isotope dilution were assessed. Reference estimates of fat-free mass density and body composition were obtained using a three-component model; (3 Results: Fat-free mass density values, predicted using Pea Pod, were biased but not significantly (p > 0.05 different from reference estimates. Body fat (%, assessed using Pea Pod, was not significantly different from reference estimates. The biological variability of fat-free mass density was 0.55% of the average value (1.0627 g/mL; (4 Conclusion: The results indicate that the Pea Pod system is accurate for groups of newborn, moderately premature infants. However, more studies where this system is used for premature infants are needed, and we provide suggestions regarding how to develop this area.

  5. An Evaluation of the Pea Pod System for Assessing Body Composition of Moderately Premature Infants.

    Science.gov (United States)

    Forsum, Elisabet; Olhager, Elisabeth; Törnqvist, Caroline

    2016-04-22

    (1) BACKGROUND: Assessing the quality of growth in premature infants is important in order to be able to provide them with optimal nutrition. The Pea Pod device, based on air displacement plethysmography, is able to assess body composition of infants. However, this method has not been sufficiently evaluated in premature infants; (2) METHODS: In 14 infants in an age range of 3-7 days, born after 32-35 completed weeks of gestation, body weight, body volume, fat-free mass density (predicted by the Pea Pod software), and total body water (isotope dilution) were assessed. Reference estimates of fat-free mass density and body composition were obtained using a three-component model; (3) RESULTS: Fat-free mass density values, predicted using Pea Pod, were biased but not significantly (p > 0.05) different from reference estimates. Body fat (%), assessed using Pea Pod, was not significantly different from reference estimates. The biological variability of fat-free mass density was 0.55% of the average value (1.0627 g/mL); (4) CONCLUSION: The results indicate that the Pea Pod system is accurate for groups of newborn, moderately premature infants. However, more studies where this system is used for premature infants are needed, and we provide suggestions regarding how to develop this area.

  6. AWSCS-A System to Evaluate Different Approaches for the Automatic Composition and Execution of Web Services Flows

    Science.gov (United States)

    Tardiole Kuehne, Bruno; Estrella, Julio Cezar; Nunes, Luiz Henrique; Martins de Oliveira, Edvard; Hideo Nakamura, Luis; Gomes Ferreira, Carlos Henrique; Carlucci Santana, Regina Helena; Reiff-Marganiec, Stephan; Santana, Marcos José

    2015-01-01

    This paper proposes a system named AWSCS (Automatic Web Service Composition System) to evaluate different approaches for automatic composition of Web services, based on QoS parameters that are measured at execution time. The AWSCS is a system to implement different approaches for automatic composition of Web services and also to execute the resulting flows from these approaches. Aiming at demonstrating the results of this paper, a scenario was developed, where empirical flows were built to demonstrate the operation of AWSCS, since algorithms for automatic composition are not readily available to test. The results allow us to study the behaviour of running composite Web services, when flows with the same functionality but different problem-solving strategies were compared. Furthermore, we observed that the influence of the load applied on the running system as the type of load submitted to the system is an important factor to define which approach for the Web service composition can achieve the best performance in production. PMID:26068216

  7. New composite nitrite-free and low-nitrite meat-curing systems using natural colorants.

    Science.gov (United States)

    Eskandari, Mohammad H; Hosseinpour, Sara; Mesbahi, Gholamreza; Shekarforoush, Shahram

    2013-09-01

    Nitrite-free and low-nitrite meat-curing systems were developed to eliminate or reduce nitrite in frankfurter-type sausages. Different composite meat-curing mixtures were formulated using cochineal and paprika as natural colorants, sodium hypophosphite (SHP) as antimicrobial agent, butylated hydroxyanisole (BHA) as antioxidant and sodium nitrite. The treatment, which contained 0.015% cochineal, most closely resembled the 120 ppm NaNO2 in its ability to create cured-meat color. BHA was found to be a strong antioxidant at the 30 ppm level in cooked sausages during refrigerated storage for 5 weeks. All treatments containing 40 ppm sodium nitrite were successful in replicating sensory attributes of frankfurter samples. Our findings support the use of SHP as possible antibotulinal agent in nitrite-free meat-curing systems.

  8. Development of bioadhesive chitosan superporous hydrogel composite particles based intestinal drug delivery system.

    Science.gov (United States)

    Chavda, Hitesh; Modhia, Ishan; Mehta, Anant; Patel, Rupal; Patel, Chhagan

    2013-01-01

    Bioadhesive superporous hydrogel composite (SPHC) particles were developed for an intestinal delivery of metoprolol succinate and characterized for density, porosity, swelling, morphology, and bioadhesion studies. Chitosan and HPMC were used as bioadhesive and release retardant polymers, respectively. A 3(2) full factorial design was applied to optimize the concentration of chitosan and HPMC. The drug loaded bioadhesive SPHC particles were filled in capsule, and the capsule was coated with cellulose acetate phthalate and evaluated for drug content, in vitro drug release, and stability studies. To ascertain the drug release kinetics, the drug release profiles were fitted for mathematical models. The prepared system remains bioadhesive up to eight hours in intestine and showed Hixson-Crowell release with anomalous nonfickian type of drug transport. The application of SPHC polymer particles as a biomaterial carrier opens a new insight into bioadhesive drug delivery system and could be a future platform for other molecules for intestinal delivery.

  9. Outage and Capacity Performance Evaluation of Distributed MIMO Systems over a Composite Fading Channel

    Directory of Open Access Journals (Sweden)

    Wenjie Peng

    2014-01-01

    Full Text Available The exact closed-form expressions regarding the outage probability and capacity of distributed MIMO (DMIMO systems over a composite fading channel are derived. This is achieved firstly by using a lognormal approximation to a gamma-lognormal distribution when a mobile station (MS in the cell is in a fixed position, and the so-called maximum ratio transmission/selected combining (MRT-SC and selected transmission/maximum ratio combining (ST-MRC schemes are adopted in uplink and downlink, respectively. Then, based on a newly proposed nonuniform MS cell distribution model, which is more consistent with the MS cell hotspot distribution in an actual communication environment, the average outage probability and capacity formulas are further derived. Finally, the accuracy of the approximation method and the rationality of the corresponding theoretical analysis regarding the system performance are proven and illustrated by computer simulations.

  10. Thermal Performance of Ablative/ Ceramic Composite

    Directory of Open Access Journals (Sweden)

    Adriana STEFAN

    2014-12-01

    Full Text Available A hybrid thermal protection system for atmospheric earth re-entry based on ablative materials on top of ceramic matrix composites is investigated for the protection of the metallic structure in oxidative and high temperature environment of the space vehicles. The paper focuses on the joints of ablative material (carbon fiber based CALCARB® or cork based NORCOAT TM and Ceramic Matrix Composite (CMC material (carbon fibers embedded in silicon carbide matrix, Cf/SiC, SICARBON TM or C/C-SiC using commercial high temperature inorganic adhesives. To study the thermal performance of the bonded materials the joints were tested under thermal shock at the QTS facility. For carrying out the test, the sample is mounted into a holder and transferred from outside the oven at room temperature, inside the oven at the set testing temperature (1100°C, at a heating rate that was determined during the calibration stage. The dwell time at the test temperature is up to 2 min at 1100ºC at an increasing rate of temperature up to ~ 9,5°C/s. Evaluating the atmospheric re-entry real conditions we found that the most suited cooling method is the natural cooling in air environment as the materials re-entering the Earth atmosphere are subjected to similar conditions. The average weigh loss was calculated for all the samples from one set, without differentiating the adhesive used as the weight loss is due to the ablative material consumption that is the same in all the samples and is up to 2%. The thermal shock test proves that, thermally, all joints behaved similarly, the two parts withstanding the test successfully and the assembly maintaining its integrity.

  11. Novel hydroxyapatite/carboxymethylchitosan composite scaffolds prepared through an innovative "autocatalytic" electroless coprecipitation route.

    Science.gov (United States)

    Oliveira, J M; Costa, S A; Leonor, I B; Malafaya, P B; Mano, J F; Reis, R L

    2009-02-01

    A developmental composite scaffold for bone tissue engineering applications composed of hydroxyapatite (HA) and carboxymethylchitosan (CMC) was obtained using a coprecipitation method, which is based on the "autocatalytic" electroless deposition route. The results revealed that the pores of the scaffold were regular, interconnected, and possess a size in the range of 20-500 microm. Furthermore, the Fourier transform infra-red spectrum of the composite scaffolds exhibited all the characteristic peaks of apatite, and the appearance of typical bands from CMC, thus showing that coprecipitation of both organic and inorganic phases was effective. The X-ray diffraction pattern of composite scaffolds demonstrated that calcium-phosphates consisted of crystalline HA. From microcomputed tomography analysis, it was possible to determine that composite scaffolds possess a 58.9% +/- 6% of porosity. The 2D morphometric analysis demonstrated that on average the scaffolds consisted of 24% HA and 76% CMC. The mechanical properties were assessed using compressive tests, both in dry and wet states. Additionally, in vitro tests were carried out to evaluate the water-uptake capability, weight loss, and bioactive behavior of the composite scaffolds. The novel hydroxyapatite/carboxymethylchitosan composite scaffolds showed promise whenever degradability and bioactivity are simultaneously desired, as in the case of bone tissue-engineering scaffolding applications.

  12. Analysis of an emergency diesel generator control system by compositional model checking. MODSAFE 2010 work report

    Energy Technology Data Exchange (ETDEWEB)

    Lahtinen, J.; Bjoerkman, K.; Valkonen, J.; Frits, J.; Niemelae, I.

    2010-12-15

    Digital instrumentation and control (I and C) systems containing programmable logic controllers are challenging to verify. They enable complicated control functions and the state spaces (number of distinct values of inputs, outputs and internal memory) of the designs easily become too large for comprehensive manual inspection. Model checking is a formal method that can be used for verifying that systems have been correctly designed. A number of efficient model checking systems are available which provide analysis tools that are able to determine automatically whether a given state machine model satisfies the desired safety properties. The practical case analysed in this research project is called an 'emergency diesel generator control system' and its purpose is to provide reserve power to critical devices and computers that must be available without interruption. This report describes 1) the development of a compositional approach for checking the models in large system designs, 2) the development of a modular model checking approach for modelling function block diagrams with the Uppaal model checker and 3) the experience of utilising the new modelling approaches in practice. (orig.)

  13. Comparison of the microtensile bond strength of different composite core materials and bonding systems to a fiber post (DT Light

    Directory of Open Access Journals (Sweden)

    Lelya Sadighpour

    2013-10-01

    Full Text Available   Background and Aims: Retention and stability of the post and core system is the key factor for success of final restoration . The aim of this study was to evaluate the microtensile bond strength of the different composite core materials and bonding systems to a fiber post.   Materials and Methods: To evaluate the bond strength of the composite resins to a fiber post ( DT light post 60 posts were divided into six groups : group A: Heliomolar Flow + Seal Bond, group B: Heliomolar Flow + SE Bond , group C: Valux Plus + Seal Bond , group D: Valux Plus + SE Bond , group E: Corecem + Seal Bond, group F: Corecem + SE Bond. All samples were thermocycled for 5000 cycles (5-55 0C and cut into four bars for the microtensile bond strength test. Failure modes were identified using a stereomicroscope. Data were analysed using One-way ANOVA and Tukey HSD post hoc test (P<0.05.   Results: The interaction between composite resin materials and bonding systems were positive. The conventional hybrid composite (Valux Plus had significantly higher bond strength compared with the core specific flowable composite (Corecem when Seal Bond was applied as bonding agent (P<0.05. However, when SE Bond was utilized hybrid composite demonstrated significantly lower bond strength than that of other two groups (P<0.05.   Conclusion: The performance of a particular composite is affected by the bonding system that is applied. A single composite resin may have different bond strength when combined with different bonding system.

  14. Análisis psicométrico del Cuestionario de Motivos del Consumo de Alcohol (CMC en escolares de la ciudad de Bogotá

    Directory of Open Access Journals (Sweden)

    Leonardo Pardo Jaime

    2016-07-01

    Full Text Available El objetivo del presente estudio consistió en analizar las propiedades psicométricas del Cuestionario de Motivos del Consumo de Alcohol (CMC en escolares de la ciudad de Bogotá. Para ello, se contó con 206 participantes, a quienes se les aplicó el cuestionario. Los resultados fueron objeto de un análisis factorial exploratorio por medio de la extracción de componentes principales, con rotación Varimax, así como de un análisis de confiabilidad por alfa de Cronbach. Los mismos muestran 4 factores con apropiada carga factorial tanto por factor como por reactivo, explicando el 73,359% de la varianza, y un índice de confiabilidad de ,945. Así entonces, el Cuestionario de Motivos del Consumo de Alcohol (CMC presenta una estructura similar a otros estudios, lo que indica que es una escala con adecuada validez de constructo y, por lo tanto, confiable para utilizarse en escolares bogotanos. Abstract The objective of this psychometric study is to analyze the psychometric properties of the Drinking Motives Questionnaire (DMQ in school children in Bogotá city. For this, there were chosen 206 sample participants who were administered the questionnaire, applying an exploratory factor analysis by using a principal component extraction with Varimax rotation, and a Cronbach’s alpha reliability analysis was also performed. The results show four factors with an appropriate factor load, by factor and by reactive, explaining a variance of 73.359% , and a reliability index of 945. The results show that the Drinking motives Questionnaire (CMC show a similar structure in comparison with surveys made in other countries. This indicates an appropriate construct validity, and reliability for its use in school children in Bogotá city.

  15. Ligand-Mediated Stabilization of Low Temperature Metal Eutectics and Their Use in Composite Systems

    Science.gov (United States)

    Finkenauer, Lauren R.

    The objective of this thesis is to contribute to the understanding of the behavior of the liquid metal eutectic gallium/indium (EGaIn) in composite systems and provide a platform for the development of functional hybrid nanocomposites. Contributions are regarding (i) the investigation of the electromechanical coupling performance of EGaIn as electrodes in a soft electrostatic transducer and (ii) the effectiveness of organic surfactants to stabilize EGaIn nanoparticles in organic solvents. For the first portion, a completely soft dielectric elastomer actuator (DEA) using EGaIn electrodes was fabricated and evaluated. Experimental actuation of the DEA showed high agreement with a generalized NeoHookean constitutive law, assuming uniaxial pre-stretch and considering the device saddle deformation. The expected conductive behavior of the liquid alloy was confirmed, and further efforts have focused on the development and stabilization of EGaIn nanodroplets, which do not exhibit the problems associated with larger pools of EGaIn (such as leakage) and can be applied to soft multifunctional materials. A computational procedure was developed for calculating suspended EGaIn nanoparticle mass in order to determine reaction yields using applied Mie theory and optical characterization techniques (dynamic light scattering and UV/Vis spectrophotometry). This method calculated total mass to within 20% when applied to a known system. A systematic study evaluating particle yield as a function of aliphatic surfactant composition and concentration (and solvent type) revealed a pronounced dependence of nanodroplet formation on the solvent type as well as surfactant structure. Ethanol (EtOH) was found to be the most effective solvent for the formation and stabilization of EGaIn nanodroplets, in which only thiol-based surfactants were found to improve nanodroplet yield. Results suggest a stabilization mechanism other than the expected self-assembled monolayer (SAM) formation. The research

  16. Draft report on melt point as a function of composition for urania-based systems

    Energy Technology Data Exchange (ETDEWEB)

    Valdez, James A [Los Alamos National Laboratory; Byler, Darrin D [Los Alamos National Laboratory

    2012-06-08

    This report documents the testing of a urania (UO{sub 2.00}) sample as a baseline and the attempt to determine the melt point associated with 4 compositions of urania-ceria and urania-neodymia pseudo binaries provided by ORNL, with compositions of 95/5, and 80/20 and of (U/Ce)O{sub 2.00} and (U/Nd)O{sub 2.00} in the newly developed ceramic melt point determination system. A redesign of the system using parts fabricated from tungsten was undertaken in order to help prevent contamination and tungsten carbide formation in the crucibles. The previously developed system employed mostly graphite parts that were shown to react with the sample containment black-body crucible leading to unstable temperature readings and crucible failure, thus the redesign. Measured melt point values of UO{sub 2.00} and U{sub 0.95}Ce{sub 0.05}O{sub 2.00}, U{sub 0.80}Ce{sub 0.20}O{sub 2.00}, U{sub 0.95}Nd{sub 0.05}O{sub 2.00} and U{sub 0.80}Nd{sub 0.20}O{sub 2.00} were measured using a 2-color pyrometer. The value measured for UO{sub 2.00} was consistent with the published accepted value 2845 C {+-} 25 C, although a wide range of values has been published by researchers and will be discussed later in the text. For comparison, values obtained from a published binary phase diagram of UO{sub 2}-Nd{sub 2}O{sub 3} were used for comparison with our measure values. No literature melt point values for comparison with the measurements performed in this study were found for (U/Ce)O{sub 2.00} in our stoichiometry range.

  17. A novel processed food classification system applied to Australian food composition databases.

    Science.gov (United States)

    O'Halloran, S A; Lacy, K E; Grimes, C A; Woods, J; Campbell, K J; Nowson, C A

    2017-08-01

    The extent of food processing can affect the nutritional quality of foodstuffs. Categorising foods by the level of processing emphasises the differences in nutritional quality between foods within the same food group and is likely useful for determining dietary processed food consumption. The present study aimed to categorise foods within Australian food composition databases according to the level of food processing using a processed food classification system, as well as assess the variation in the levels of processing within food groups. A processed foods classification system was applied to food and beverage items contained within Australian Food and Nutrient (AUSNUT) 2007 (n = 3874) and AUSNUT 2011-13 (n = 5740). The proportion of Minimally Processed (MP), Processed Culinary Ingredients (PCI) Processed (P) and Ultra Processed (ULP) by AUSNUT food group and the overall proportion of the four processed food categories across AUSNUT 2007 and AUSNUT 2011-13 were calculated. Across the food composition databases, the overall proportions of foods classified as MP, PCI, P and ULP were 27%, 3%, 26% and 44% for AUSNUT 2007 and 38%, 2%, 24% and 36% for AUSNUT 2011-13. Although there was wide variation in the classifications of food processing within the food groups, approximately one-third of foodstuffs were classified as ULP food items across both the 2007 and 2011-13 AUSNUT databases. This Australian processed food classification system will allow researchers to easily quantify the contribution of processed foods within the Australian food supply to assist in assessing the nutritional quality of the dietary intake of population groups. © 2017 The British Dietetic Association Ltd.

  18. High energy ballistic and fracture comparison between multilayered armor systems using non-woven curaua fabric composites and aramid laminates

    Directory of Open Access Journals (Sweden)

    Fábio de Oliveira Braga

    2017-10-01

    Full Text Available For personal protection against high kinetic energy projectiles, multilayered armor systems (MAS are usually the best option. They combine synergistically the properties of different materials such as ceramics, composites and metals. In the present work, ballistic tests were performed to evaluate multilayered armor systems (MAS using curaua non-woven fabric epoxy composites as second layer. A comparison to a MAS using aramid (Kevlar™ fabric laminates was made. The results showed that the curaua non-woven fabric composites are suitable to the high ballistic applications, and are promising substitutes for aramid fabric laminates. Keywords: Composite, Natural fiber, Curaua fiber, Non-woven fabric, Aramid laminate, Ballistic test

  19. Effect of Dental Restorative Material Type and Shade on Characteristics of Two-Layer Dental Composite Systems

    Directory of Open Access Journals (Sweden)

    Atefeh Karimzadeh

    Full Text Available Abstract The purpose of this study was to investigate the effects of shade and material type and shape in dental polymer composites on the hardness and shrinkage stress of bulk and two-layered restoration systems. For this purpose, some bulk and layered specimens from three different shades of dental materials were prepared and light-cured. The experiments were carried out on three types of materials: conventional restorative composite, nanohybrid composite and nanocomposite. Micro-indentation experiment was performed on the bulk and also on each layer of layered restoration specimens using a Vicker's indenter. The interface between the two layers was studied by scanning electron microscopy (SEM. The results revealed significant differences between the values of hardness for different shades in the conventional composite and also in the nanohybrid composite. However, no statistically significant difference was observed between the hardness values for different shades in the nanocomposite samples. The layered restoration specimens of different restorative materials exhibited lower hardness values with respect to their bulk specimens. The reduction in the hardness value of the layered conventional composite samples was higher than those of the nanocomposite and nanohybrid composite specimens indicating more shrinkage stresses generated in the conventional composite restorations. According to the SEM images, a gap was observed between the two layers in the layered restorations.

  20. Changes in chroma of two indirect composite materials polymerized with different polymerization systems.

    Science.gov (United States)

    Ayano, Michiya

    2012-01-01

    This study evaluated chroma change in two composite materials (Sinfony and Pearleste) polymerized with two different systems. Disk specimens were prepared using a metal halide unit (Hyper LII) and an exposure time of 60 to 180 s. The proprietary polymerization systems (Visio and Pearlcure systems) were used as the reference polymerization modes. After storage at 37°C for 24 h, CIE 1976 L*a*b* values were measured by using a dental chroma meter (ShadeEye NCC) with a gray background. The specimens were then immersed in water or tea. Color change from baseline to 4 weeks was evaluated by measuring ΔL*, Δa*, and Δb*, after which ΔE*(ab) values were calculated. The brightness of Sinfony specimens was reduced by tea immersion. The color of both materials shifted to yellow after tea immersion, although color change in Sinfony specimens was greater than that in Pearleste specimens. For both materials, color change was less after polymerization with the metal halide unit. In conclusion, Sinfony polymerized with the Hyper LII unit, and Pearleste polymerized with either system, were stable against discoloration due to tea immersion.

  1. Grapevine yield components and composition of Isabel grape produced according to the organic and conventional systems

    Directory of Open Access Journals (Sweden)

    Miele Alberto

    2016-01-01

    Full Text Available There is an increasing demand for organic grapes by the juice industry of Serra Gaúcha, Brazil. This region presents a humid and hot summer, ideal climatic conditions for the development of a number of diseases. To control such diseases and problems brought about by other organisms, growers apply pesticides on the grapevines which may leave residues in grapes. However, in general, grapes produced by organic system have lower yield, but there is a lack of research data on this subject. Thus, an experiment was carried out over three years in order to compare the yield components and the physicochemical composition of the must of Isabel grapes conducted in both production systems. When the grapes were ripe, variables related to yield components were evaluated, such as the number of clusters/vine, yield/vine and weight/cluster. Then the grapes were sampled and taken to the laboratory where they were crushed and the musts were centrifuged and analyzed. The 3-year data mean were submitted to correlation analysis and Principal Component Analysis. The results show that conventional grapevines produced 2.18 times more than organic. However, the grapes from the organic system had higher density, Brix, pH, Brix/titratable acidity ratio, P and Mg but lower K, and Ca varied little between both production systems.

  2. Fluid geochemistry of the Mondragone hydrothermal systems (southern Italy): water and gas compositions vs. geostructural setting

    Science.gov (United States)

    Cuoco, Emilio; Minissale, Angelo; Di Leo, Antonella "Magda"; Tamburrino, Stella; Iorio, Marina; Tedesco, Dario

    2017-10-01

    The geochemistry of natural thermal fluids discharging in the Mondragone Plain has been investigated. Thermal spring emergences are located along the Tyrrhenian coast in two different areas: near Padule-S. Rocco (41°7.5'N 13°53.4'E) at the foot of Mt. Petrino, and near Levagnole (41°8.5'N 13°51.3'E) at the foot of Mt. Pizzuto. The water isotopic composition of both thermal discharges is lighter than the one of local shallow groundwater (δ18O ≅ -6.3‰ SMOW vs. ≅ -5.9‰; δD ≅ -40‰ SMOW vs. ≅ -36‰, respectively) as a consequence of inland higher altitude of recharge by rainfall, suggesting that thermal water undergoes a deep and long flow-path before emerging along the coast. The chemical composition of the highest temperature samples of two areas points that fluids in the hydrothermal reservoir(s) interact with similar lithologies, since they are both hosted in the lower sedimentary carbonate formations of the Campanian-Latial Apennine succession. However, the two spring systems are different in terms of temperature and salinity (Levagnole: ≅50 °C and 8.9 g/L vs. Padule: ≅32 °C and 7.4 g/L, respectively). The higher salinity of Levagnole springs is due to a longer interaction with evaporite material embedded in Miocene sedimentary formations and to the eventual mixing, during rising, with fresh seawater close to the seashore. The chemical and isotopic composition of the free gases associated with the springs, again suggests a different source of the two hydrothermal systems. Comparing the 3He/4He measured ratios with other gas emissions located NE and SE of Mt. Massico-Roccamonfina alignment, it is evident that the Levagnole thermal springs are related to the northern Latial mantle wedge where the 3He/4He is about 0.5 R/Ra, whereas the Padule-S. Rocco springs, although being only 3.5 km south of Levagnole, are related to the Campanian mantle wedge where R/Ra is always ≥2.0. Such a difference in 3He/4He ratio in a very short distance

  3. Geochemistry and strontium isotopic composition of mineralforming solutions of hydrothermal systems of southern Kamchatka

    Energy Technology Data Exchange (ETDEWEB)

    Pampura, V.D.; Plyusnin, G.S.; Sandimirova, G.P.

    1980-01-01

    In order to understand the genesis of hydrothermal systems in the regions of recent volcanism, the chemical composition of hydrothermal waters was studied. In addition, the behavior of strontium in the process of hydrothermal alteration of volcanic aquifers was considered. The data on strontium isotopy for thermal waters, effusives and volcanic-sedimentary rocks of the Pauzhetka hydrothermal region are given. For depth-derived sodium-chloride hydrothermal waters /sup 87/Sr//sup 86/Sr values lie within the range of 0.7033 to 0.7056. Significant differences of /sup 87/Sr//sup 86/Sr values in seawater and sodium-chloride hydrothermal waters at all levels of their geochemical metamorphism were noted. This is considered to be evidence of the absence of seawater in the chemical composition of hydrothermal waters of the Pauzhetka type. To determine the cause of low /sup 87/Sr//sup 86/Sr values of depth-derived sodium-chloride hydrothermal waters, the strontium isotopy of country rocks was studied and /sup 87/Sr//sup 86/Sr = 0.702 to 0.705 have been determined. The data indicate the possibility that recent hydrothermal waters inherited a ratio of /sup 87/Sr//sup 86/Sr = 0.703 to 0.704 at the aquifer level.

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

    Science.gov (United States)

    Li, Xiaopeng; Li, Mo; Song, Gangbing

    2015-02-01

    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.

  5. Influence of kid rearing systems on milk composition and yield of Murciano-Granadina dairy goats.

    Science.gov (United States)

    Peris, S; Caja, G; Such, X; Casals, R; Ferret, A; Torre, C

    1997-12-01

    One-hundred eight lactations of Murciano-Granadina goats from different years were used to compare two kid rearing systems. Goats were separated into two groups: suckling and milking. Dams in the suckling group were milked once daily until kids were weaned (wk 0 to 7) and then were milked twice daily. Dams in the milking group were separated from their kids at 48 h after birth; then, kids were raised artificially, and goats were milked twice daily. Total milk yield was estimated according to the oxytocin method during suckling. Stage of lactation, parity, prolificacy, and year effects on milk yield and composition were also studied. As expected, during the first 7 wk of lactation, marketable milk was higher for dams that were milked than for dams that were suckled. Neither milk yield nor milk composition throughout the entire lactation was affected by group or prolificacy with the exception of the percentage of milk CP. The lactation curve peaked at wk 4 or 5 and declined slowly afterward. First parity goats had the lowest milk yield but the highest fat and protein percentages. Third parity goats had the highest milk yield. The separation of kids from their dams after birth did not affect total lactation performance because of the minimal importance of the neuroendocrine milk ejection reflex in goats compared with that of other ruminants.

  6. World Automata: a compositional approach to model implicit communication in hierarchical Hybrid Systems

    Directory of Open Access Journals (Sweden)

    Marta Capiluppi

    2013-08-01

    Full Text Available We propose an extension of Hybrid I/O Automata (HIOAs to model agent systems and their implicit communication through perturbation of the environment, like localization of objects or radio signals diffusion and detection. The new object, called World Automaton (WA, is built in such a way to preserve as much as possible of the compositional properties of HIOAs and its underlying theory. From the formal point of view we enrich classical HIOAs with a set of world variables whose values are functions both of time and space. World variables are treated similarly to local variables of HIOAs, except in parallel composition, where the perturbations produced by world variables are summed. In such way, we obtain a structure able to model both agents and environments, thus inducing a hierarchy in the model and leading to the introduction of a new operator. Indeed this operator, called inplacement, is needed to represent the possibility of an object (WA of living inside another object/environment (WA.

  7. Particulate organic matter composition in a semi-enclosed Periantarctic system: the Straits of Magellan

    Directory of Open Access Journals (Sweden)

    M. Fabiano

    1999-12-01

    Full Text Available The elemental and biochemical composition of particulate organic matter (POM was investigated in the Straits of Magellan during February-March 1991. Twenty-two stations were selected in order to identify different areas of the Magellan ecosystem from a trophic point of view. The Strait of Magellan can be divided into three subsystems characterized by different hydrological and geomorphological conditions. Seston concentrations were mostly constrained by physical events, particularly the influence of oceanic and land run-off water inputs and the strong vertical mixing and resuspension events. POM composition displayed quali-quantitative differences between the three areas. In the first subsystem, influenced by Pacific waters, the low seston and POM concentrations and the high POC/Chl-a ratio values indicated the general predominance of the detrital and heterotrophic fractions. In the second subsystem, characterized by superficial stratification, higher seston and organic matter concentrations and lower values of POC/Chl-a ratio were found, indicating that this subsystem was influenced by an active autotrophic component. Shallow waters with intense tidal regime and strong vertical mixing characterized the third subsystem, connected to the Atlantic Ocean, which displayed an increasing importance of the inorganic fraction (values of the POC/TSM ratio lower than in the other systems. Moreover, the third subsystem showed higher values of the RNA/DNA ratio, possibly indicating that resuspension events may enhance the metabolic state of the organic particles mainly dominated by heterotrophic components.

  8. Data Quality Indicators Composition and Calculus: Engineering and Information Systems Approaches

    Directory of Open Access Journals (Sweden)

    Leon REZNIK

    2015-02-01

    Full Text Available Big Data phenomenon is a result of novel technological developments in sensor, computer and communication technologies. Nowadays more and more data are produced by nanoscale photonic, optoelectronic and electronic devices. However, their quality characteristics could be very low. The paper proposes new methods of the data management with huge data amounts that is based on associating of data quality indicators with each data entity. To achieve this goal, one needs to define the composition of the data quality indicators and to develop their integration calculus. As data quality evaluation involves multi-disciplinary research, various metrics have been investigated. The paper describes two major approaches in assigning the data quality indicators and developing their integration calculus. The information systems approach employs traditional high-level metrics like data accuracy, consistency and completeness. The engineering approach utilizes signal characteristics processed with the probability based calculus. The data quality metrics composition and calculus are discussed. The tools developed to automate the metrics selection and calculus procedures are presented. The user- friendly interface examples are provided.

  9. Fish Community Composition and Habitat Use in the Eg-Uur River System, Mongolia

    Directory of Open Access Journals (Sweden)

    Norman Mercado-Silva

    2008-06-01

    Full Text Available Mongolian rivers and their fi sh communities have suffered severe impacts from anthropogenic activities. However, the remoteness of some systems has allowed for the conservation of unique fi sh faunas, including robust populations of Hucho taimen . Conservation of H. taimen requires understanding the composition and ecology of other fi shes in the community. Using multiple sampling techniques, direct observation, and existing literature, we assessed the composition, relative abundance, and ecological attributes of fi shes in the Eg-Uur watershed (Selenge basin. We collected 6 of 12 species known in the watershed. Phoxinus cf. phoxinus and Lota lota were the most and least abundant species, respectively. We failed to detect H. taimen , indicating low abundance or unknown habitat requirements for juveniles. We compared the effectiveness of different sampling techniques (with electro fi shing producing the highest species richness, constructed length-weight relationships for four species , and identi fi ed ecological attributes (i.e., trophic guild, preferred habitat for resident fi shes.

  10. Polymer hydrogel functionalized with biodegradable nanoparticles as composite system for controlled drug delivery.

    Science.gov (United States)

    Rossi, Filippo; Ferrari, Raffaele; Castiglione, Franca; Mele, Andrea; Perale, Giuseppe; Moscatelli, Davide

    2015-01-09

    The possibility to direct pharmacological treatments targeting specific cell lines using polymer nanoparticles is one of the main novelties and perspectives in nanomedicine. However, sometimes, the ability to maintain NPs localized at the site of the injection that work as a drug reservoir can represent a good and complementary option. In this direction we built a composite material made of polymeric hydrogel functionalized with polymer NPs. ϵ-caprolactone and polyethylene glycol have been copolymerized in a two-step synthesis of PEGylated NPs, while hydrogel was synthesized through polycondensation between NPs, agarose and branched polyacrylic acid. NP functionalization was verified with Fourier transform infrared spectroscopy (FTIR), high resolution magic angle spinning-nuclear magnetic resonance (HRMAS-NMR) spectroscopy and release kinetics from a hydrogel matrix and compared with NPs only physically entrapped into a hydrogel matrix. The characteristics of the resulting composite hydrogel-NPs system were studied both in terms of rheological properties and in its ability to sustain the release of To-Pro3, used as a drug mimetic compound to represent a promising drug delivery device.

  11. Sources and composition of organic matter for bacterial growth in a large European river floodplain system (Danube, Austria)

    OpenAIRE

    Besemer, Katharina; Luef, Birgit; Preiner, Stefan; Eichberger, Birgit; Agis, Martin; Peduzzi, Peter

    2009-01-01

    Dissolved and particulate organic matter (DOM and POM) distribution, lignin phenol signatures, bulk elemental compositions, fluorescence indices and microbial plankton (algae, bacteria, viruses) in a temperate river floodplain system were monitored from January to November 2003. We aimed to elucidate the sources and compositions of allochthonous and autochthonous organic matter (OM) in the main channel and a representative backwater in relation to the hydrological regime. Additionally, bacter...

  12. Investigation of Structure and Physico-Mechanical Properties of Composite Materials Based on Copper - Carbon Nanoparticles Powder Systems

    Directory of Open Access Journals (Sweden)

    Kovtun V.

    2015-04-01

    Full Text Available Physico-mechanical and structural properties of electrocontact sintered copper matrix- carbon nanoparticles composite powder materials are presented. Scanning electron microscopy revealed the influence of preliminary mechanical activation of the powder system on distribution of carbon nanoparticles in the metal matrix. Mechanical activation ensures mechanical bonding of nanoparticles to the surface of metal particles, thus giving a possibility for manufacture of a composite with high physico-mechanical properties.

  13. Carbohydrate and lipid composition of vegetables, and bioavalability assessed in a rat model: Impact different cultivation systems

    OpenAIRE

    Jørgensen, Henry; Bach Knudsen, Knud Erik; Lauridsen, Charlotte

    2011-01-01

    Environmental as well as cultivation factors may greatly influence the chemical composition of plants. The main factors affecting chemical composition of foodstuff is level and type of fertilizer (conventional and organic cultivation systems), location or soiltype and year of harvest. Organic foods are defined as products which are produced under controlled cultivation conditions characterized by the absence of synthetic fertilizers and very restricted use of pesticides. Dietary carbohy...

  14. Atrapados en la red del am@r. Un análisis del lenguaje y las emociones en la CMO Caught in the web of l@ve. An analysis of language and emotions in CMC

    Directory of Open Access Journals (Sweden)

    Sotomayor Gilda

    2008-01-01

    Full Text Available El artículo trata de ver al Homo amans en el contexto actual de las Nuevas Tecnologías, dedicando especial atención a las relaciones sentimentales que se establecen en la CMO (Comunicación Mediada por Ordenador. Lo que se busca es entender el fenómeno del intercambio y comunicación emocional en un medio aparentemente tan frío como es Internet; para ello se aborda la Red, no desde una perspectiva tecnológica sino más bien antropológica y psicológica relacionada al tema emocional, eje central en torno al cual gira la vida del hombre. Se empieza haciendo un análisis del mundo de los sentimientos y las emociones para luego abordar el del lenguaje, elementos con los cuales se construye la comunicación humana. Posteriormente se ve, de forma específica, el lenguaje escrito en la CMO. Finalmente se da luces sobre la implicación de este tema en el campo educativo, haciendo hincapié en la formación sentimental a través de la formación de la competencia relacional o interactiva, en la que se encuentra profundamente implicado el sistema emocional del ser humano. The article tries to see the Homo amans in the current context of the New Technologies, with special attention to love relationships that are established in the CMC (Computer- Mediated Communication. What we are looking for is to understand the phenomenon of the emotional exchange and communication in an environment as seemingly cold as Internet. The Net is used for these purposes, but not from a technological perspective but anthropological and psychological, related to the emotional subject, central axis around which men life is rotated. It begins with an analysis of the feelings and the emotions and then it tackles the language, elements with which the human communication is built. Subsequently, we deal specifically with the written language in the CMC. Finally we will focus on the implication of this subject in the education sector, emphasizing the creation of feelings through

  15. Networks of dissipative systems compositional certification of stability, performance, and safety

    CERN Document Server

    Arcak, Murat; Packard, Andrew

    2016-01-01

    This book addresses a major problem for today’s large-scale networked systems: certification of the required stability and performance properties using analytical and computational models. On the basis of illustrative case studies, it demonstrates the applicability of theoretical methods to biological networks, vehicle fleets, and Internet congestion control. Rather than tackle the network as a whole —an approach that severely limits the ability of existing methods to cope with large numbers of physical components— the book develops a compositional approach that derives network-level guarantees from key structural properties of the components and their interactions. The foundational tool in this approach is the established dissipativity theory, which is reviewed in the first chapter and supplemented with modern computational techniques. The book blends this theory with the authors’ recent research efforts at a level that is accessible to graduate students and practising engineers familiar with only th...

  16. The enteric nervous system promotes intestinal health by constraining microbiota composition.

    Directory of Open Access Journals (Sweden)

    Annah S Rolig

    2017-02-01

    Full Text Available Sustaining a balanced intestinal microbial community is critical for maintaining intestinal health and preventing chronic inflammation. The gut is a highly dynamic environment, subject to periodic waves of peristaltic activity. We hypothesized that this dynamic environment is a prerequisite for a balanced microbial community and that the enteric nervous system (ENS, a chief regulator of physiological processes within the gut, profoundly influences gut microbiota composition. We found that zebrafish lacking an ENS due to a mutation in the Hirschsprung disease gene, sox10, develop microbiota-dependent inflammation that is transmissible between hosts. Profiling microbial communities across a spectrum of inflammatory phenotypes revealed that increased levels of inflammation were linked to an overabundance of pro-inflammatory bacterial lineages and a lack of anti-inflammatory bacterial lineages. Moreover, either administering a representative anti-inflammatory strain or restoring ENS function corrected the pathology. Thus, we demonstrate that the ENS modulates gut microbiota community membership to maintain intestinal health.

  17. The enteric nervous system promotes intestinal health by constraining microbiota composition

    Science.gov (United States)

    Mittge, Erika K.; Ganz, Julia; Troll, Josh V.; Melancon, Ellie; Wiles, Travis J.; Alligood, Kristin; Stephens, W. Zac; Eisen, Judith S.; Guillemin, Karen

    2017-01-01

    Sustaining a balanced intestinal microbial community is critical for maintaining intestinal health and preventing chronic inflammation. The gut is a highly dynamic environment, subject to periodic waves of peristaltic activity. We hypothesized that this dynamic environment is a prerequisite for a balanced microbial community and that the enteric nervous system (ENS), a chief regulator of physiological processes within the gut, profoundly influences gut microbiota composition. We found that zebrafish lacking an ENS due to a mutation in the Hirschsprung disease gene, sox10, develop microbiota-dependent inflammation that is transmissible between hosts. Profiling microbial communities across a spectrum of inflammatory phenotypes revealed that increased levels of inflammation were linked to an overabundance of pro-inflammatory bacterial lineages and a lack of anti-inflammatory bacterial lineages. Moreover, either administering a representative anti-inflammatory strain or restoring ENS function corrected the pathology. Thus, we demonstrate that the ENS modulates gut microbiota community membership to maintain intestinal health. PMID:28207737

  18. Effect of Putrescine Treatment on Chilling Injury, Fatty Acid Composition and Antioxidant System in Kiwifruit.

    Science.gov (United States)

    Yang, Qingzhen; Wang, Feng; Rao, Jingping

    2016-01-01

    We investigated the effects of different concentrations (0, 1, 2 and 4 mM) of putrescine on chilling injury, fruit quality, ethylene production rate, fatty acid composition and the antioxidant system of cold-stored kiwifruit (Actinidia chinensis Planch. var. chinensis 'Hongyang'). We achieved a significant decrease in ethylene production, maintained fruit quality and alleviated chilling injury during storage via treatment with 2 mM putrescine. Furthermore, putrescine treatment inhibited increases in superoxide anion production rate and H2O2 concentration, while maintaining higher membrane lipid unsaturation as well as increased activities of superoxide dismutase and catalase. In addition, putrescine treatment enhanced the activities of antioxidant enzymes related to the ascorbate-glutathione cycle while causing higher levels of ascorbic acid and reduced glutathione. Our results suggest that induced tolerance against chilling injury via putrescine treatment in cold-stored kiwifruit may be due to enhanced antioxidant activity, increased unsaturation of membrane lipids, and inhibited ethylene production.

  19. Modelling of composite concrete block pavement systems applying a cohesive zone model

    DEFF Research Database (Denmark)

    Skar, Asmus; Poulsen, Peter Noe

    This paper presents a numerical analysis of the fracture behaviour of the cement bound base material in composite concrete block pavement systems, using a cohesive zone model. The functionality of the proposed model is tested on experimental and numerical investigations of beam bending tests....... The pavement is modelled as a simple slab on grade structure and parameters influencing the response, such as analysis technique, geometry and material parameters are studied. Moreover, the analysis is extended to a real scale example, modelling the pavement as a three-layered structure. It is found...... block pavements. It is envisaged that the methodology implemented in this study can be extended and thereby contribute to the ongoing development of rational failure criteria that can replace the empirical formulas currently used in pavement engineering....

  20. Failure prediction of ±55° glass/epoxy composite pipes using system identification modelling

    Science.gov (United States)

    Yi, A. J.; Majid, M. S. A.; Nor, A. M.; Ridzuan, M. J. M.; Yaacob, S.

    2017-10-01

    Black-box modelling using system identification method to predict the performance of glass fibre reinforced epoxy (GRE) composite pipe under multiaxial loading stress ratio is presented. In this study, both linear and nonlinear models were derived namely; linear time-invariant parametric model and artificial neural network model. The models derived are to approximate the pure hydrostatic loading performance using GRE pipes with winding angles of ±55°. Three different linear model structures were derived, and the best fit model achieved at 96.64% of best fit. On the other hand, the Artificial Neural Network (ANN) modelling showed better accuracy with the best fit of 99.82%. Finally, the point of failure at which first damage takes place predicted by the models derived was validated using experimental data.

  1. FoodCASE: A system to manage food composition, consumption and TDS data.

    Science.gov (United States)

    Presser, Karl; Weber, David; Norrie, Moira

    2018-01-01

    Food and nutrition scientists, nowadays, need to manage an increasing amount of data regarding food composition, food consumption and Total Diet Studies (TDS). The corresponding datasets can contain information about several thousand different foods, in different versions from different studies. FoodCASE is a system that has been developed to manage these different datasets. It also support flexible means of linking between datasets and generally provide support for the different processes involved in the acquisition, management and processing of data. In this paper, the most important concepts to implement existing guidelines and standards for proper food data management are presented, as well as different use cases of data import and proofs of concepts demonstrating the ability to manage data in FoodCASE. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. A Portable Ultrasonic Nondestructive Inspection System for Metal Matrix Composite Track Shoes

    Science.gov (United States)

    Mi, Bao; Zhao, Xiaoliang; Qian, Tao; Stevenson, Mark; Kwan, Chiman; Owens, Steven E.; Royer, Roger L.; Tittmann, Bernhard R.; Raju, Basavaraju B.

    2007-03-01

    Cast aluminum track shoes reinforced with metal matrix composite (MMC) inserts at heavy loading areas such as center splines and sprocket windows are light in weight, and can resist high temperature and wear. Various defects such as disbonds at the insert-substrate interface, cracks and porosity in the MMC layer, etc. can be introduced during the manufacturing process and/or in service. This paper presents a portable ultrasonic system to automatically inspect tank track shoes for disbond. Ultrasonic pulse/echo inspection has shown good reliability for disbond detection. A prototype sensor array fixture has been designed and fabricated to prove the feasibility. Good agreements between the sensor fixture results and ultrasonic C-scan images were obtained.

  3. A model for the composition modifications in the Cu-Sb-O system

    Energy Technology Data Exchange (ETDEWEB)

    Stan, M.

    1997-05-01

    THE SN-SB-CU-O SYSTEM HAS BEEN EXTENSIVELY STUDIED BUT SYSTEMATIC PHASE EQUILIBRIUM STUDIES HAVE NOT BEEN APPROACHED. THE SYSTEM CONTAINS USEFUL CERAMICS WITH SPECIFIC ELECTRICAL AND MAGNETIC PROPERTIES, EMPLOYED AS SENSORS, ELECTRODES AND CATALYSTS. AS A PRELIMINARY STEP TO THE PHASE DIAGRAM CALCULATION, THE PAPER AIMS TO PRESENT A MODEL FOR THE COMPOSITION MODIFICATIONS IN THE CU-SB-O SYSTEM, WHICH IS THE MOST COMPLEX OF ALL SUBSYSTEMS. EXOTHERMIC EFFECTS ALONG WITH MASS INCREASES CAN BE OBSERVED IN DTA/GA CURVES, WERE ASSIGNED, FOR ALL SAMPLES, TO SB2O3 AND SB2O4 OXIDATION AND TO CUSB2O6 FORMATION: (1) APPROX. EQUAL 500 DIG C SB2O3 + 1/2 O2 DOUBLE RIGHT ARROW SB2O4; (2) {gt} 750 DIG C SB2O4 + CUO + 1/2 O2 DOUBLE RIGHT ARROW CUSB2O6. FOR THE SAMPLES HAVING CUO IN EXCESS, THE REDUCTION OF CUO TO CUO AND THE FORMATION OF THE CU4SBO4.5 COMPOUND SIMULTANEOUSLY OCCUR: {gt} 950 dig C CUSB2O6 + 7CuO double right arrow (1-r) CUSB2O6+7(1-r)cow+ 2rCu4SbO4.5 + 2rO2 where rEpsilon (0, 1) is the fraction of CUSB2O6 that transforms into Cu4SbO4.5. All the experimental evidences show that the Equations (1), (2) and (3) are good descriptions of the transformations that occurs in the CuO-Sb2O3 system along with the temperature. If the reactions are considered as completed, including a=1 in IQ. (3), then the quantity of oxygen that is gained or lost can be calculated for each sample. It is important to note that Equations (2) and (3) should be carefully solved because of the excess quantities of cow or SB2O4 that can be found in some samples. The calculated values of mass variation are in a good agreement with those obtained from the experimental GT diagrams. The atomic fractions of Cu, Sb and Awe content change in the system and they can be also calculated. The model assumes that at room temperature the compositions lay on the CuO-Sb2O3 line as shown in Fig. 1.

  4. Nutrient composition and respiration characteristics of silkworms in the Bioregenerative Life Support System

    Science.gov (United States)

    Tong, Ling; Yu, Xiaohui; Liu, Hong

    As the appropriate space animal candidate, silkworm(Bombyx Mori L.) can supply animal food for taikonauts and consume inedible parts of plants in Bioregenerative Life Support Sys-tem(BLSS). Due to the features of BLSS, the silkworm breeding method in the system differ-ent from the conventional one is feeding the silkworm in the first three developing stages with mulberry leaves and with lettuce leaves in the latter two developing stages. Therefore, it is nec-essary to investigate the biochemical components and respiration characteristics of silkworms raised with this method to supply data bases for the inclusion of silkworms in the system to conduct system experiments. The nutrient compositions of silkworm powder (SP) which are the grinded and freeze-dried silkworm on the 3rd day in the fifth developing stage containing protein, fat, vitamins, minerals and fatty acids were determined with international standard analyzing methods in this study. The results showed that SP was rich in protein and amino acids. There were twelve kinds of essential vitamins, nine kinds of minerals and twelve kinds of fatty acids in SP. In contrast, SP had much better nutrient components than snail, fish, chicken, beef and pork as animal food for crew members. Moreover, 359 kCal can be generated per 100g of SP (dry weight). The respirations of silkworm during its whole growing process under two main physiological statuses which were eating and non-eating leaves were studied. According to the results measured by the animal respiration measuring system, there were much difference among the respirations of silkworms under the two main physiological statuses. The amounts of O2 inhaled and CO2 exhaled by the silkworms when they were eating leaves were more than those under the non-eating status. Even under the same status, the respiration characteristics of silkworms in five different developing stages were also different from one an-other. The respiratory quotients of silkworms under two

  5. Enhanced Damage Tolerance High Temperature Composite Using a Biomimetic Toughening System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Lightweight composite structures are required to provide space vehicles with increased thrust-to-weight ratio and durability. New methods for toughening composites...

  6. Carbon Observations from Geostationary Earth Orbit as Part of an Integrated Observing System for Atmospheric Composition

    Science.gov (United States)

    Edwards, D. P.

    2015-12-01

    This presentation describes proposed satellite carbon measurements from the CHRONOS mission. The primary goal of this experiment is to measure the atmospheric pollutants carbon monoxide (CO) and methane (CH4) from geostationary orbit, with hourly observations of North America at high spatial resolution. CHRONOS observations would provide measurements not currently available or planned as part of a surface, suborbital and satellite integrated observing system for atmospheric composition over North America. Carbon monoxide is produced by combustion processes such as urban activity and wildfires, and serves as a proxy for other combustion pollutants that are not easily measured. Methane has diverse anthropogenic sources ranging from fossil fuel production, animal husbandry, agriculture and waste management. The impact of gas exploration in the Western States of the USA and oil extraction from the Canadian tar sands will be particular foci of the mission, as will the poorly-quantified natural CH4 emissions from wetlands and thawing permafrost. In addition to characterizing pollutant sources, improved understanding of the domestic CH4 budget is a priority for policy decisions related to short-lived climate forcers. A primary motivation for targeting CO is its value as a tracer of atmospheric pollution, and CHRONOS measurements will provide insight into local and long-range transport across the North American continent, as well as the processes governing the entrainment and venting of pollution in and out of the planetary boundary layer. As a result of significantly improved characterization of diurnal changes in atmospheric composition, CHRONOS observations will find direct societal applications for air quality regulation and forecasting. We present a quantification of this expected improvement in the prediction of near-surface concentrations when CHRONOS measurements are used in Observation System Simulation Experiments (OSSEs). If CHRONOS and the planned NASA Earth

  7. An Experimental Investigation of Silicone-to-Metal Bond Strength in Composite Space Docking System Seals

    Science.gov (United States)

    Gaier, James R.; Siamidis, John; Larkin, Elizabeth M. G.

    2010-01-01

    The National Aeronautics and Space Administration (NASA) is currently developing a new universal docking mechanism for future space exploration missions called the Low Impact Docking System (LIDS). A candidate LIDS main interface seal design is a composite assembly of silicone elastomer seals vacuum molded into grooves in an electroless nickel plated aluminum retainer. The strength of the silicone-tometal bond is a critical consideration for the new system, especially due to the presence of small areas of disbond created during the molding process. In the work presented herein, seal-to-retainer bonds of subscale seal specimens with different sizes of intentional disbond were destructively tensile tested. Nominal specimens without intentional disbonds were also tested. Tension was applied either uniformly on the entire seal circumference or locally in one short circumferential length. Bond failure due to uniform tension produced a wide scatter of observable failure modes and measured load-displacement behaviors. Although the preferable failure mode for the seal-to-retainer bond is cohesive failure of the elastomer material, the dominant observed failure mode under the uniform loading condition was found to be the less desirable adhesive failure of the bond in question. The uniform tension case results did not show a correlation between disbond size and bond strength. Localized tension was found to produce failure either as immediate tearing of the elastomer material outside the bond region or as complete peel-out of the seal in one piece. The obtained results represent a valuable benchmark for comparison in the future between adhesion loads under various separation conditions and composite seal bond strength.

  8. Effects of fishing technique on assessing species composition in aquatic systems in semi-arid Brazil

    Directory of Open Access Journals (Sweden)

    ESF Medeiros

    Full Text Available In most ecological field research, appropriate sampling is critical for the understanding of processes underlying fish populations and communities, and is even more important in heterogeneous environments such as the aquatic systems of the semi-arid region of Brazil. This study intends to make a contribution to the development of sampling programs and gear selection in aquatic systems of semi-arid Brazil by evaluating the effects of different fishing techniques on the assessment of richness and composition of the fish fauna in selected aquatic environments. Six sites were selected to represent typical artificial (reservoirs and natural (intermittent streams environments and four different types of sampling gear were applied to each site during four occasions. The present study shows that when selecting sampling techniques to be used in aquatic systems in semi-arid Brazil, one must consider the objectives of the study, e.g. ecological or taxonomic, in order to decide on inclusion of rare species in the sampling population. Also, the effect of the sampling gear on natural abundances of fish must be considered given that some sampling techniques are highly detrimental to fish population numbers.

  9. UT system composition and welding flaw classification for SWP stability estimation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.Y.; Yoo, Y.T. [Dept. of Mechanical Engineering, Chosun Univ., Gwangju (Korea); Song, K.S.; Kim, C.H.; Yang, D.J. [Dept. of Precision Mechanical Engineering, Chosun Univ. Graduate School, Gwangju (Korea)

    2004-07-01

    The purpose of this research is stability estimation of plant structure through classification and recognition about welding flaw in SWP(spiral welding pipe). And, in this research, we used nondestructive test based on ultrasonic test as inspection method, and made up inspection robot in order to control of ultrasonic probe on the SWP surface, and programmed to signal processing code and pattern classifying code by user made programming code. Inspection robot is simply constructed as 2-axes because of welding bead with fixed pitch. So, inspection of welding part can be possible as composition of inspection part for tracking on welding line. For evaluation of flaw signal is reflected on welding flaw, user-made program codes are composed of signal processing and Bayesian classifier and perceptron neural network and back-propagation neural network. And then, we confirmed to superiority of neural network method compared with Bayesian classifier for classification and recognition rate. According to this result, we selected back-propagation neural network as classification and recognition method about the system of SWP stability Estimation. Through this process, we proved efficiency on the system of SWP stability Estimation, and constructed on the base of the system of SWP stability Estimation for the application in industrial fields. (orig.)

  10. Influence of the spectral composition of LED lighting system on plants cultivation in a darkroom

    Science.gov (United States)

    Blaszczak, Urszula J.; Abdel Aziz, Dzamil; Gryko, Lukasz

    2017-08-01

    Agriculture is one of the most important areas of the world economy. However, due to dependency on weather conditions, it is strongly industrialized, for example by introducing additional lighting improving the efficiency of plants growth. Construction and operation of light-emitting diodes provides new possibilities in research and application of new concepts in agricultural lighting. The aim of the work was to investigate the effect of various spectra of light on the efficiency of photosynthesis and the growth of selected species of plants. For this purpose two grow-boxes with dedicated LED-based lighting systems were constructed and placed in the darkroom with controlled temperature. In each box lighting system provided different spectral composition of light and it was possible to adjust the ratio of blue and red as well as the irradiance level. In the paper we present the construction of the grow-boxes and the results of 3 cycles of experiments conducted with this system. During the first cycle two groups of tested plants were cultivated in the LED grow-boxes with constant irradiance level and the third group in natural light conditions. During the second cycle the irradiance in both boxes was gradually increased from 8 W/m2 to 38 W/m2. During the third cycle the irradiance was set to 38 W/m2 during the whole period (max power MRED module) to get the maximum possible intensity of photosynthesis.

  11. A combined stereo-photogrammetry and underwater-video system to study group composition of dolphins

    Science.gov (United States)

    Bräger, S.; Chong, A.; Dawson, S.; Slooten, E.; Würsig, B.

    1999-11-01

    One reason for the paucity of knowledge of dolphin social structure is the difficulty of measuring individual dolphins. In Hector's dolphins, Cephalorhynchus hectori, total body length is a function of age, and sex can be determined by individual colouration pattern. We developed a novel system combining stereo-photogrammetry and underwater-video to record dolphin group composition. The system consists of two downward-looking single-lens-reflex (SLR) cameras and a Hi8 video camera in an underwater housing mounted on a small boat. Bow-riding Hector's dolphins were photographed and video-taped at close range in coastal waters around the South Island of New Zealand. Three-dimensional, stereoscopic measurements of the distance between the blowhole and the anterior margin of the dorsal fin (BH-DF) were calibrated by a suspended frame with reference points. Growth functions derived from measurements of 53 dead Hector's dolphins (29 female : 24 male) provided the necessary reference data. For the analysis, the measurements were synchronised with corresponding underwater-video of the genital area. A total of 27 successful measurements (8 with corresponding sex) were obtained, showing how this new system promises to be potentially useful for cetacean studies.

  12. The DWPF product composition control system at Savannah River: Statistical process control algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Postles, R.L.; Brown, K.G.

    1991-12-31

    The DWPF Process batch-blends aqueous radwaste (PHA) with solid radwaste (Sludge) in a waste receipt vessel (the SRAT). The resulting SRAT-Batch is transferred to the next process vessel (the SME) and there blended with ground glass (Frit) to produce a batch of feed slurry. The SME-Batch is passed to a subsequent hold tank (the MFT) which feeds a Melter continuously. The Melter produces a molten glass wasteform which is poured into stainless steel canisters for cooling and, ultimately, shipment to and storage in a geologic Repository. The Repository will require that the glass wasteform be resistant to leaching by any underground water that might contact it. In addition, there are processing constraints on Viscosity and Liquidus Temperature of the melt. The Product Composition Control System (PCCS) is the system intended to ensure that the melt will be Processible and that the glass wasteform will be Acceptable. Within the PCCS, the SPC Algorithm is the device which guides control of the DWPF process. The SPC Algorithm is needed to control the multivariate DWPF process in the face of uncertainties (variances and covariances) which arise from this process and its supply, sampling, modeling, and measurement systems.

  13. Rutaecarpine and evodiamine selected as β1-AR inhibitor candidates using β1-AR/CMC-offline-UPLC/MS prevent cardiac ischemia-reperfusion injury via energy modulation.

    Science.gov (United States)

    Xue, Hui; Cheng, Yongjie; Wang, Xin; Yue, Yuan; Zhang, Weifang; Li, Xiaoni

    2015-11-10

    In the present study, an offline analytical method combining β1-adrenergic receptor/cell membrane chromatography (β1-AR/CMC) with ultra-performance liquid chromatography/mass spectrometry (UPLC/MS) was used for direct recognition, separation, and identification of β1-AR inhibitors from Evodia rutaecarpa (Juss) Benth, by which rutaecarpine and evodiamine were screened and identified as potential β1-AR antagonists and the β1-AR inhibition activity of them was confirmed by downregulation of cAMP and PKA in vitro test. In addition, the results of in vivo pharmacological trials revealed that rutaecarpine (1.1mg/ml) and evodiamine (1.1mg/ml) attenuated myocardial infarct size injured by myocardial ischemia/reperfusion, improved metabolism disorders between fatty acid and glucose, increased the content of ATP, Ca(2+)-ATPase activity and reduced the content of peroxisome proliferator-activated receptor α (PPARα) protein level. Thus, the β1-AR/CMC-offline-UPLC/MS method developed in this study could be used as an effective alternative for screening β1-AR binding bioactive components in traditional Chinese medicines and the bioactive components could be used to remedy cardiac diseases via energy modulation. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Fabrication of CMC-g-PAM superporous polymer monoliths via eco-friendly Pickering-MIPEs for superior adsorption of methyl violet and methylene blue

    Science.gov (United States)

    Wang, Feng; Zhu, Yongfeng; Wang, Wenbo; Zong, Li; Lu, Taotao; Wang, Aiqin

    2017-06-01

    A series of superporous carboxymethylcellulose-graft-poly(acrylamide) (CMC-g-PAM) polymer monoliths presenting interconnected pore structure and excellent adsorption properties were prepared by one-step free-radical grafting polymerization reaction of CMC and acrylamide (AM) in the oil-in-water (O/W) Pickering-medium internal phase emulsions (Pickering-MIPEs) composed of non-toxic edible oil as a dispersion phase and natural Pal nanorods as stabilizers. The effects of Pal dosage, AM dosage, and co-surfactant Tween-20 (T-20) on the pore structures of the monoliths were studied. It was revealed that the well-defined pores were formed when the dosages of Pal and T-20 are 9-14% and 3%, respectively. The porous monolith can rapidly adsorb 1585 mg/g of methyl violet (MV) and 1625 mg/g of methylene blue (MB). After the monolith was regenerated by adsorption-desorption process for 5 times, the adsorption capacities still reached 92.1% (for MV) and 93.5% (for MB) of the initial maximum adsorption capacities. The adsorption process was fitted with Langmuir adsorption isotherm model and pseudo-second-order adsorption kinetic model very well, which indicate that mono-layer chemical adsorption mainly contribute to the high-capacity adsorption for dyes. The superporous polymer monolith prepared from eco-friendly Pickering-MIPEs shows good adsorption capacity and fast adsorption rate, which is potential adsorbent for the decontimination of dye-containing wastewater.

  15. Comparative evaluation of effect of different polishing systems on surface roughness of composite resin: An in vitro study

    Science.gov (United States)

    Chour, Rashmi G.; Moda, Aman; Arora, Arpana; Arafath, Muhmmed Y.; Shetty, Vikram K.; Rishal, Yousef

    2016-01-01

    Aims and Objectives: Satisfactory composite restoration depends upon its smooth finish, quality of polishing agents, type of composite material used, and its composition. The present study evaluated the effect of different polishing systems on the surface roughness of composite resin. Materials and Methods: Forty discs of composite were prepared and equally subjected to different finishing and polishing procedures; (i) unpolished control group, (ii) sof-lex discs, (iii) diamond tips, and (iv) Astrobrush groups. Later, the surface roughness for the entire specimen was evaluated using Profilomotor. Data were tabulated and statistically analyzed using analysis of variance and Tukey's test at significance level of 0.001. Results: Composite surface roughness after polishing was statistically significant between the groups. Sof-lex group produced lesser surface roughness compared to control, Astrobrush, and diamond group. Conclusion: The present study indicated that diamond tips can be used to remove rough surface whereas sof-lex can be used for final finish and polish of the composite restoration. PMID:27652251

  16. NEW METHOD OF OBTAINING GELATINE-SiO₂ COMPOSITE SYSTEMS USING 3-GLYCIDOXYPROPYLTRIMETHOXYSILANE AND 3-CHLOROPROPYLTRIMETHOXYSILANE

    Directory of Open Access Journals (Sweden)

    Agnieszka Martyla

    2017-09-01

    Full Text Available Composite materials based on biopolymers are an attractive alternative to conventional composites because of their high biocompatibility, biodegradability and unique functional characteristics. The method developed for the synthesis of material using glycidoxypropyltrimethoxysilane and chloropropyltrimethoxysilane is based on sol-gel processes making possible enhanced control over the final properties of the composite, such as water absorption and the hydrophobic or hydrophilic properties. Thermal studies of the composite show significant complexity of the formation process of the composite, and the possibility of the controlled carbonization into ceramic material.

  17. The Effect of Tillage System and Crop Rotation on Soil Microbial Diversity and Composition in a Subtropical Acrisol

    Directory of Open Access Journals (Sweden)

    Eric W. Triplett

    2012-10-01

    Full Text Available Agricultural management alters physical and chemical soil properties, which directly affects microbial life strategies and community composition. The microbial community drives important nutrient cycling processes that can influence soil quality, cropping productivity and environmental sustainability. In this research, a long-term agricultural experiment in a subtropical Acrisol was studied in south Brazil. The plots at this site represent two tillage systems, two nitrogen fertilization regimes and three crop rotation systems. Using Illumina high-throughput sequencing of the 16S rRNA gene, the archaeal and bacterial composition was determined from phylum to species level in the different plot treatments. The relative abundance of these taxes was correlated with measured soil properties. The P, Mg, total organic carbon, total N and mineral N were significantly higher in the no-tillage system. The microbial diversity was higher in the no-tillage system at order, family, genus and species level. In addition, overall microbial composition changed significantly between conventional tillage and no-tillage systems. Anaerobic bacteria, such as clostridia, dominate in no-tilled soil as well as anaerobic methanogenic archaea, which were detected only in the no-tillage system. Microbial diversity was higher in plots in which only cereals (oat and maize were grown. Soil management influenced soil biodiversity on Acrisol by change of composition and abundance of individual species.

  18. Automated ablation of dental composite using an IR pulsed laser coupled to a plume emission spectral feedback system

    Science.gov (United States)

    Jang, Andrew T.; Chan, Kenneth H.; Fried, Daniel

    2017-02-01

    Dental composites are used as restorative materials for filling cavities, shaping, and covering teeth for esthetic purposes, and as adhesives. Dentists spend more time replacing existing restorations that fail than they do placing new restorations. Tooth colored restorations are difficult to differentiate from the surrounding tooth structure making them challenging to remove without damaging healthy tooth structure. Previous studies have demonstrated that CO2 lasers in conjunction with spectral feedback can be used to selectively remove composite from tooth surfaces. The purpose of this study is to assemble a system that is feasible for clinical use incorporating a spectral feedback system, a scanning system, articulating arm and a clinical handpiece and then evaluate the performance of that system on extracted teeth. In addition, the selectivity of composite removal was analyzed using a high-speed optical coherence tomography system that is suitable for clinical use. The system was capable of rapidly removing composite from small preparations on tooth occlusal surfaces with a mean loss of enamel of less than 20-μm.

  19. Lithological and hydrological influences on ground-water composition in a heterogeneous carbonate-clay aquifer system

    Science.gov (United States)

    Kauffman, S.J.; Herman, J.S.; Jones, B.F.

    1998-01-01

    The influence of clay units on ground-water composition was investigated in a heterogeneous carbonate aquifer system of Miocene age in southwest Florida, known as the Intermediate aquifer system. Regionally, the ground water is recharged inland, flows laterally and to greater depths in the aquifer systems, and is discharged vertically upward at the saltwater interface along the coast. A depth profile of water composition was obtained by sampling ground water from discrete intervals within the permeable carbonate units during coring and by squeezing pore water from a core of the less-permeable clay layers. A normative salt analysis of solute compositions in the water indicated a marine origin for both types of water and an evolutionary pathway for the clay water that involves clay diagenesis. The chemical composition of the ground water in the carbonate bedrock is significantly different from that of the pore water in the clay layers. Dissolution of clays and opaline silica results in high silica concentrations relative to water in other parts of the Intermediate aquifer system. Water enriched in chloride relative to the overlying and underlying ground water recharges the aquifer inland where the confining clay layer is absent, and it dissolves carbonate and silicate minerals and reacts with clays along its flow path, eventually reaching this coastal site and resulting in the high chloride and silica concentrations observed in the middle part of the Intermediate aquifer system. Reaction-path modeling suggests that the recharging surficial water mixes with sulfate-rich water upwelling from the Upper Floridan aquifer, and carbonate mineral dissolution and precipitation, weathering and exchange reactions, clay mineral diagenesis, clay and silica dissolution, organic carbon oxidation, and iron and sulfate reduction result in the observed water compositions.A study was conducted to clarify the influence of clay units on ground-water composition in a heterogeneous

  20. Development of Biopolymer Composite Films Using a Microfluidization Technique for Carboxymethylcellulose and Apple Skin Particles

    Directory of Open Access Journals (Sweden)

    Inyoung Choi

    2017-06-01

    Full Text Available Biopolymer films based on apple skin powder (ASP and carboxymethylcellulose (CMC were developed with the addition of apple skin extract (ASE and tartaric acid (TA. ASP/CMC composite films were prepared by mixing CMC with ASP solution using a microfluidization technique to reduce particle size. Then, various concentrations of ASE and TA were incorporated into the film solution as an antioxidant and an antimicrobial agent, respectively. Fourier transform infrared (FTIR, optical, mechanical, water barrier, and solubility properties of the developed films were then evaluated to determine the effects of ASE and TA on physicochemical properties. The films were also analyzed for antioxidant effect on 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and antimicrobial activities against Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica, and Shigella flexneri. From the results, the ASP/CMC film containing ASE and TA was revealed to enhance the mechanical, water barrier, and solubility properties. Moreover, it showed the additional antioxidant and antimicrobial properties for application as an active packaging film.

  1. Developing Large-Scale Bayesian Networks by Composition: Fault Diagnosis of Electrical Power Systems in Aircraft and Spacecraft

    Science.gov (United States)

    Mengshoel, Ole Jakob; Poll, Scott; Kurtoglu, Tolga

    2009-01-01

    In this paper, we investigate the use of Bayesian networks to construct large-scale diagnostic systems. In particular, we consider the development of large-scale Bayesian networks by composition. This compositional approach reflects how (often redundant) subsystems are architected to form systems such as electrical power systems. We develop high-level specifications, Bayesian networks, clique trees, and arithmetic circuits representing 24 different electrical power systems. The largest among these 24 Bayesian networks contains over 1,000 random variables. Another BN represents the real-world electrical power system ADAPT, which is representative of electrical power systems deployed in aerospace vehicles. In addition to demonstrating the scalability of the compositional approach, we briefly report on experimental results from the diagnostic competition DXC, where the ProADAPT team, using techniques discussed here, obtained the highest scores in both Tier 1 (among 9 international competitors) and Tier 2 (among 6 international competitors) of the industrial track. While we consider diagnosis of power systems specifically, we believe this work is relevant to other system health management problems, in particular in dependable systems such as aircraft and spacecraft. (See CASI ID 20100021910 for supplemental data disk.)

  2. Bond strength durability of a resin composite on a reinforced ceramic using various repair systems.

    Science.gov (United States)

    Ozcan, Mutlu; Valandro, Luiz Felipe; Amaral, Regina; Leite, Fabiola; Bottino, Marco Antonio

    2009-12-01

    This study compared the durability of repair bond strength of a resin composite to a reinforced ceramic after three repair systems. Alumina-reinforced feldspathic ceramic blocks (Vitadur-alpha) (N=30) were randomly divided into three groups according to the repair method: PR-Porcelain Repair Kit (Bisco) [etching with 9.5% hydrofluoric acid+silanization+adhesive]; CJ-CoJet Repair Kit (3M ESPE) [(chairside silica coating with 30microm SiO(2)+silanization (ESPE)-Sil)+adhesive (Visio-Bond)]; CL-Clearfil Repair Kit [diamond surface roughening, etching with 40% H(3)PO(4)+Clearfil Porcelain Bond Activator+Clearfil SE Bond)]. Resin composite was photo-polymerized on each conditioned ceramic block. Non-trimmed beam specimens were produced for the microtensile bond strength (microTBS) tests. In order to study the hydrolytic durability of the repair methods, the beam specimens obtained from each block were randomly assigned to two conditions. Half of the specimens were tested either immediately after beam production (Dry) or after long-term water storage (37 degrees C, 150 days) followed by thermocyling (12,000 cycles, 5-55 degrees C) in a universal testing machine (1mm/min). Failure types were analyzed under an optical microscope and SEM. microTBS results were significantly affected by the repair method (p=0.0001) and the aging conditions (p=0.0001) (two-way ANOVA, Tukey's test). In dry testing conditions, PR method showed significantly higher (p<0.001) repair bond strength (19.8+/-3.8MPa) than those of CJ and CL (12.4+/-4.7 and 9.9+/-2.9, respectively). After long-term water storage and thermocycling, CJ revealed significantly higher results (14.5+/-3.1MPa) than those of PR (12.1+/-2.6MPa) (p<0.01) and CL (4.2+/-2.1MPa) (p<0.001). In all groups when tested in dry conditions, cohesive failure in the composite accompanied with adhesive failure at the interface (mixed failures), was frequently observed (76%, 80%, 65% for PR, CJ and CL, respectively). After aging conditions

  3. SEM investigation of composite restoration adaptation to enamel after use of total etch and self etch adhesive system

    Directory of Open Access Journals (Sweden)

    Dačić Stefan

    2009-01-01

    Full Text Available Introduction Quality and durability of enamel/composite interface essentially depend on an adhesive restorative system. Objective The aim of this study was to evaluate the quality of marginal adaptation of composite adhesive systems to enamel by scanning electron microscopy (SEM, and to analyze the morphology of the enamel surface along margins of composite restorations, following exposure to cariogenic solution. Methods The study material included 56 extracted human third molars. Class V cavities were prepared with margins at enamel. Cavities were restored with Single Bond/Z250 and Single Bond/Filtek flow, using the total etch adhesive system, and Prompt-L-Pop/Z250 and Prompt-L-Pop/Filtek flow, using the self etch adhesive system. After the restorative procedure, the restorations were submitted to demineralization during 7 and 28 days. Samples were stored in a cariogenic solution (lactic acid, pH 4.5; 0.1 M at 37°C or in deionized water (the control group. The margins of restorations and perimarginal enamel were examined by scanning electron microscope (SEM. The gap formations around restoration were measured on cervical, occlusal and approximate margins. Results The usage of the total etch adhesive system showed statistically significant lower marginal gap width around composite restoration, compared with the self etch system (p<0.01. The SEM examination also showed perimarginal enamel zones presenting several signs of demineralization and erosion (alteration of rods, porosities after acting of a cariogenic solution, in both adhesive methods. Less alteration was found on the enamel surfaces not included in the perimarginal zone. Conclusion Treating the cavity with 35% phosphoric acid in the total etch system significantly improved the adaptation of the composite resins to enamel, compared with the self etch treatment. Stronger demineralization of the perimarginal enamel in a cariogenic solution was observed around all restorations in both

  4. Cu-As Decoupling in Hydrothermal Systems: A Link Between Pyrite Chemistry and Fluid Composition

    Science.gov (United States)

    Reich, M.; Tardani, D.; Deditius, A.; Chryssoulis, S.; Wrage, J.; Sanchez-Alfaro, P.; Andrea, H.; Cinthia, J.

    2016-12-01

    Chemical zonations in pyrite have been recognized in most hydrothermal ore deposit types, showing in some cases marked oscillatory alternation of metals and metalloids in pyrite growth zones (e.g., of Cu-rich, As-(Au)-depleted zones and As-(Au)-rich, Cu-depleted zones). This decoupled geochemical behavior of Cu and As has been interpreted as a result of chemical changes in ore-forming fluids, although direct evidence connecting fluctuations in hydrothermal fluid composition with metal partitioning into pyrite growth zones is still lacking. Here we report a comprehensive trace element database of pyrite from an active hydrothermal system, the Tolhuaca Geothermal System (TGS) in southern Chile. We combined high-spatial resolution and X-ray mapping capabilities of electron microprobe analysis (EMPA) with low detection limits and depth-profiling capabilities of secondary-ion mass spectrometry (SIMS) in a suite of pyrite samples retrieved from a 1 km drill hole that crosses the argillic and propylitic alteration zones of the geothermal system. We show that the concentrations of precious metals (e.g., Au, Ag), metalloids (e.g., As, Sb, Se, Te), and base and heavy metals (e.g., Cu, Co, Ni, Pb) in pyrite at the TGS are significant. Among the elements analyzed, arsenic, Cu and Co are the most abundant with concentrations that vary from sub-ppm levels to a few wt. %. Pyrites from the deeper propylitic zone do not show significant zonation and high Cu-(Co)-As concentrations correlate with each other. In contrast, well-developed zonations were detected in pyrite from the shallow argillic alteration zone, where Cu(Co)-rich, As-depleted cores alternate with Cu(Co)-depleted, As-rich rims. These microanalytical data were contrasted with chemical data of fluid inclusion in quartz veins (high Cu/Na and low As/Na) and borehole fluids (low Cu/Na and high As/Na) reported at the TGS, showing a clear correspondence between Cu and As concentrations in pyrite-forming fluids and chemical

  5. Composition, mineralogy, and porosity of multiple asteroid systems from visible and near-infrared spectral data

    Science.gov (United States)

    Lindsay, S. S.; Marchis, F.; Emery, J. P.; Enriquez, J. E.; Assafin, M.

    2015-02-01

    We aim to provide a taxonomic and compositional characterization of Multiple Asteroid Systems (MASs) located in the main belt (MB) using visible (0.45-0.85 μm) and near-infrared (0.7-2.5 μm) spectral data of 42 MB MASs. The compositional and mineralogical analysis is applied to determine meteorite analogs for the MASs, which, in turn, are applied to the MAS density measurements of Marchis et al. (Marchis et al. [2012]. Icarus 221, 1130-1161) to estimate the porosity of the systems. The macroporosities are used to evaluate the primary MAS formation hypotheses. Our spectral survey consists of visible and near-infrared spectral data. The visible observing campaign includes 25 MASs obtained using the Southern Astrophysical Research (SOAR) telescope with the Goodman High Throughput Spectrometer. The infrared observing campaign includes 34 MASs obtained using the NASA Infrared Telescope Facility (IRTF) with the SpeX spectragraph. For completeness, both visible and NIR data sets are supplemented with publicly available data, and the data sets are combined where possible. The MASs are classified using the Bus-DeMeo taxonomic system. In order to determine mineralogy and meteorite analog, we perform a NIR spectral band parameter analysis using a new analysis routine, the Spectral Analysis Routine for Asteroids (SARA). The SARA routine determines band centers, areas, and depths by utilizing the diagnostic absorption features near 1- and 2-μm due to Fe2+ crystal field transitions in olivine + pyroxene and pyroxene, respectively. The band parameter analysis provides the Gaffey subtype for the S-complex MASs; the relative abundance olivine-to-pyroxene ratio; and olivine and pyroxene modal abundances for S-complex and V-type MASs. This mineralogical information is then applied to determine meteorite analogs. Through applying calibration studies, we are able to determine the H, L, and LL meteorite analogs for 15 MASs with ordinary chondrite-like (OC) mineralogies. We observe an

  6. Mycological composition in the rhizosphere of winter wheat in different crop production systems

    Science.gov (United States)

    Frac, Magdalena; Lipiec, Jerzy; Usowicz, Boguslaw

    2010-05-01

    Fungi play an important role in the soil ecosystem as decomposers of plant residues, releasing nutrients that sustain and stimulate processes of plant growth. Some fungi possess antagonistic properties towards plant pathogens. The structure of plant and soil communities is influenced by the interactions among its component species and also by anthropogenic pressure. In the study of soil fungi, particular attention is given to the rhizosphere. Knowledge of the structure and diversity of the fungal community in the rhizosphere lead to the better understanding of pathogen-antagonist interactions. The aim of this study was to evaluate the mycological composition of the winter wheat rhizosphere in two different crop production systems. The study was based on a field experiment established in 1994 year at the Experimental Station in South-East Poland. The experiment was conducted on grey-brown podzolic soil. In this experiment winter wheat were grown in two crop production systems: ecological and conventional - monoculture. The research of fungi composition was conducted in 15th year of experiment. Rhizosphere was collected two times during growing season, in different development stage: shooting phase and full ripeness phase. Martin medium and the dilutions 10-3 and 10-4 were used to calculate the total number cfu (colony forming units) of fungi occurring in the rhizosphere of winter wheat. The fungi were identified using Czapeka-Doxa medium for Penicillium, potato dextrose agar for all fungi and agar Nirenberga (SNA) for Fusarium. High number of antagonistic fungi (Penicillium sp., Trichoderma sp.) was recorded in the rhizosphere of wheat in ecological system. The presence of these fungi can testify to considerable biological activity, which contributes to the improvement of the phytosanitary condition of the soil. However, the decrease of the antagonistic microorganism number in the crop wheat in monoculture can be responsible for appearance higher number of the

  7. [Analysis on composition principles of prescriptions for nausea by using traditional Chinese medicine inheritance support system].

    Science.gov (United States)

    Han, Qi; Li, Hong-Hai; Fan, Cui-Ping; Liu, Chun; Liang, Yong-Lin

    2016-07-01

    Nausea is special in the symptoms, and is different from hiccups and vomiting. The main symptom is that the patients throw up the indigested food from the stomach regularly--if the patients have a dinner, they will throw out it in the next morning, or if the patients have a breakfast, they will throw out it at night. Nausea is common in clinic, and different physicians may use different treatment methods for it. This disease also cannot be treated efficiently and may happen repeatedly with the western medicine. In this study, the composition principles of prescriptions in past traditional Chinese medicine for nausea were analyzed and summarized by using traditional Chinese medicine inheritance support system(V2.5), hoping to provide guidance for clinical drug use and summarize the basic rules for treatment of nausea.The prescriptions for nausea in "the prescription of traditional Chinese medicine dictionary" were selected, and the information was entered into the traditional Chinese medicine inheritance support system(TCMISS) to build a database. Data mining methods such as frequency statistics, association rules, complex system entropy clustering were used to analyze and summarize the composition principles of these prescriptions. The herb frequencies of the prescriptions were finally determined; herbs with higher use frequencies were obtained; and the association rules between herbs were found. 19 commonly used herb pairs, 10 core combinations and 10 newly developed prescriptions were found. The basic pathogenesis of nausea in traditional Chinese medicine is the weakness and coldness of spleen and stomach, and the Qi adverseness of stomach. Generations of physicians' main therapeutic method for nausea is mainly to warm the middle and invigorate the spleen, lower Qi and regulate stomach. The commonly used herbs for nausea are ginger, ginseng, large head attractylodes, tuckahoe, licorice, and appropriately supplemented with the herbs of eliminating dampness and

  8. AN ARCHITECTURE FOR AUTOMATED FIRE DETECTION EARLY WARNING SYSTEM BASED ON GEOPROCESSING SERVICE COMPOSITION

    Directory of Open Access Journals (Sweden)

    F. Samadzadegan

    2013-09-01

    Full Text Available Rapidly discovering, sharing, integrating and applying geospatial information are key issues in the domain of emergency response and disaster management. Due to the distributed nature of data and processing resources in disaster management, utilizing a Service Oriented Architecture (SOA to take advantages of workflow of services provides an efficient, flexible and reliable implementations to encounter different hazardous situation. The implementation specification of the Web Processing Service (WPS has guided geospatial data processing in a Service Oriented Architecture (SOA platform to become a widely accepted solution for processing remotely sensed data on the web. This paper presents an architecture design based on OGC web services for automated workflow for acquisition, processing remotely sensed data, detecting fire and sending notifications to the authorities. A basic architecture and its building blocks for an automated fire detection early warning system are represented using web-based processing of remote sensing imageries utilizing MODIS data. A composition of WPS processes is proposed as a WPS service to extract fire events from MODIS data. Subsequently, the paper highlights the role of WPS as a middleware interface in the domain of geospatial web service technology that can be used to invoke a large variety of geoprocessing operations and chaining of other web services as an engine of composition. The applicability of proposed architecture by a real world fire event detection and notification use case is evaluated. A GeoPortal client with open-source software was developed to manage data, metadata, processes, and authorities. Investigating feasibility and benefits of proposed framework shows that this framework can be used for wide area of geospatial applications specially disaster management and environmental monitoring.

  9. A nonlinear scalable model for designing ionic polymer-metal composite actuator systems

    Science.gov (United States)

    McDaid, A. J.; Aw, K. C.; Hämmerle, E.; Xie, S. Q.

    2009-07-01

    This paper proposes a conclusive scalable model for Ionic Polymer Metal Composites (IPMC) actuators and their interactions with mechanical systems and external loads. This dynamic, nonlinear model accurately predicts the displacement and force actuation in air for a large range of input voltages. The model addresses all the requirements of a useful design tool for IPMC actuators and is intended for robotic and bio-mimetic (artificial muscle) applications which operate at low frequencies. The response of the IPMC is modeled in three stages, (i) a nonlinear equivalent electrical circuit to predict the current drawn, (ii) an electro-mechanical coupling term, representing the conversion of ion flux to a stress generated in the polymer membrane and (iii) a mechanical beam model which includes an electrically induced torque for the polymer. Mechanical outputs are in the rotational coordinate system, 'tip angle' and 'torque output', to give more practical results for the design and simulation of mechanisms. Model parameters are obtained using the dynamic time response and results are presented demonstrating excellent correspondence between the model and experimental results. This newly developed model is a large step forward, aiding in the progression of IPMCs towards wide acceptance as replacements to traditional actuators.

  10. Failure envelope modelling of glass/epoxy composite pipes using system identification method

    Science.gov (United States)

    Yi, Ang Jia; Majid, M. S. Abdul; Nor, Azuwir Mohd; Yaacob, Sazali; Ridzuan, M. J. M.

    2017-11-01

    The paper aims to model the performance of the Glass Fibre Reinforced Epoxy (GRE) composite pipe under multiaxial loading via system identification approach. System identification modelling depends on the input and output data of the experimental result. In this study, the experimental data used are obtained from a pressurised test rig. The model is based on pure hydrostatic (2H: 1A) loading using GRE pipes with three different winding angles (±45 °, ±55 °, ±63 °). Several models based on different model structures are derived for comparison to obtain the best modelling accuracy. The result shows that the transfer function method could model and has the highest efficiency compared with the experimental result. The ±45 ° pipe model have achieved 92.41% and 85.13% for both its hoop and axial model. The ±55 ° pipe model has achieved 96.64% and 86.1%. Follow by the ±63° which the best fit is 92.41% and 94.26%. At the last part of this research, the ±55° pipe model and experimental data has been use to identified when the damage occur and found that the axial strain of 78 bar can damage the experimental pipe in this research.

  11. The Composition of the Phonological Consonant System and its Functioning in Lithuanian and French Languages

    Directory of Open Access Journals (Sweden)

    Daiva Mickūnaitytė

    2014-12-01

    Full Text Available The aim of the article is to examine the composition of the phonological consonant system and its functioning in Lithuanian and French languages. We will describe the phonological consonant systems of both languages on two levels – syntagmatic and paradigmatic. On the syntagmatic level we will discuss the structure and regularities of explosive, implosive consonant distributions and inner consonant collocations. On the paradigmatic level we will focus on the paradigmatic consonant identification – peculiarities of consonant oppositions, their neutralization and the comparison of the inventory of differential features in the languages of our concern. In this work we will base ourselves only on the literary pronunciation of the French language. Colloquial French has its own peculiarities which determine the appearance of new structures of consonant collocations, therefore their description can be the object of another scholarly work. We will present French nouns without articles as to describe explosive consonant groups, it is most convenient to take a noun without an article. The structures and collocation regularities of consonant collocations are best reflected only in this form. Soft vowels and affricates which do not exist in the French language are not discussed in the article.

  12. External Thermal Insulation Composite Systems: Critical Parameters for Surface Hygrothermal Behaviour

    Directory of Open Access Journals (Sweden)

    Eva Barreira

    2014-01-01

    Full Text Available External Thermal Insulation Composite Systems (ETICS are often used in Europe. Despite its thermal advantages, low cost, and ease of application, this system has serious problems of biological growth causing the cladding defacement. Recent studies pointed that biological growth is due to high values of surface moisture content, which mostly results from the combined effect of exterior surface condensation, wind-driven rain, and drying process. Based on numerical simulation, this paper points the most critical parameters involved in hygrothermal behaviour of ETICS, considering the influence of thermal and hygric properties of the external rendering, the effect of the characteristics of the façade, and the consequences of the exterior and interior climate on exterior surface condensation, wind-driven rain, and drying process. The model used was previously validated by comparison with the results of an “in situ” campaign. The results of the sensitivity analyses show that relative humidity and temperature of the exterior air, atmospheric radiation, and emissivity of the exterior rendering are the parameters that most influence exterior surface condensation. Wind-driven rain depends mostly on horizontal rain, building’s height, wind velocity, and orientation. The drying capacity is influenced by short-wave absorbance, incident solar radiation, and orientation.

  13. Saturation Recovery Myocardial T1 Mapping with a Composite Radiofrequency Pulse on a 3T MR Imaging System.

    Science.gov (United States)

    Morita, Kosuke; Oda, Seitaro; Utsunomiya, Daisuke; Nakaura, Takeshi; Matsubara, Takatoshi; Goto, Makoto; Okuaki, Tomoyuki; Yuki, Hideaki; Nagayama, Yasunori; Kidoh, Masafumi; Hirata, Kenichiro; Iyama, Yuij; Taguchi, Narumi; Hatemura, Masahiro; Hashida, Masahiro; Yamashita, Yasuyuki

    2017-05-18

    To evaluate the effect of a composite radiofrequency (RF) pulse on saturation recovery (SR) myocardial T1 mapping using a 3T magnetic resonance (MR) system. Phantom and in vivo studies were performed with a clinical 3T MR scanner. Accuracy and reproducibility of the SR T1 mapping using conventional and composite RF pulses were first compared in phantom experiments. An in vivo study was performed of 10 healthy volunteers who were imaged with conventional and composite RF pulse methods twice each. In vivo reproducibility of myocardial T1 value and the inter-segment variability were assessed. The phantom study revealed significant differences in the mean T1 values between the two methods, and the reproducibility for the composite RF pulse was significantly smaller than that for the conventional RF pulse. For both methods, the correlations of the reference and measured T1 values were excellent (r(2) = 0.97 and 0.98 for conventional and composite RF pulses, respectively). The in vivo study showed that the mean T1 value for composite RF pulse was slightly lower than that for conventional RF pulse, but this difference was not significant (P = 0.06). The inter-segment variability for the composite RF pulse was significantly smaller than that for conventional RF pulse (P T1 measurements of the first and second scans were highly and weakly correlated to composite RF pulses (r = 0.83 and 0.29, respectively). SR T1 mapping using composite RF pulse provides accurate quantification of T1 values and can lessen measurement variability and enable reproducible T1 measurements.

  14. Acousto-ultrasonic decay in metal matrix composite panels

    Science.gov (United States)

    Kautz, Harold E.

    1995-01-01

    Acousto-ultrasonic (A-U) decay rates (UD) were measured in metal matrix composite (MMC) panels. The MMC panels had fiber architectures and cross-sectional thicknesses corresponding to those designed for aerospace turbine engine structures. The wavelength-to-thickness ratio produced by the combination of experimental frequency setting conditions and specimen geometry was found to be a key parameter for identifying optimum conditions for UD measurements. The ratio was shown to be a useful rule of thumb when applied to ceramic matrix composites (CMC)s and monolithic thermo-plastics.

  15. Comparative normal/failing rat myocardium cell membrane chromatographic analysis system for screening specific components that counteract doxorubicin-induced heart failure from Acontium carmichaeli.

    Science.gov (United States)

    Chen, Xiaofei; Cao, Yan; Zhang, Hai; Zhu, Zhenyu; Liu, Min; Liu, Haibin; Ding, Xuan; Hong, Zhanying; Li, Wuhong; Lv, Diya; Wang, Lirong; Zhuo, Xianyi; Zhang, Junping; Xie, Xiang-Qun; Chai, Yifeng

    2014-05-20

    Cell membrane chromatography (CMC) derived from pathological tissues is ideal for screening specific components acting on specific diseases from complex medicines owing to the maximum simulation of in vivo drug-receptor interactions. However, there are no pathological tissue-derived CMC models that have ever been developed, as well as no visualized affinity comparison of potential active components between normal and pathological CMC columns. In this study, a novel comparative normal/failing rat myocardium CMC analysis system based on online column selection and comprehensive two-dimensional (2D) chromatography/monolithic column/time-of-flight mass spectrometry was developed for parallel comparison of the chromatographic behaviors on both normal and pathological CMC columns, as well as rapid screening of the specific therapeutic agents that counteract doxorubicin (DOX)-induced heart failure from Acontium carmichaeli (Fuzi). In total, 16 potential active alkaloid components with similar structures in Fuzi were retained on both normal and failing myocardium CMC models. Most of them had obvious decreases of affinities on failing myocardium CMC compared with normal CMC model except for four components, talatizamine (TALA), 14-acetyl-TALA, hetisine, and 14-benzoylneoline. One compound TALA with the highest affinity was isolated for further in vitro pharmacodynamic validation and target identification to validate the screen results. Voltage-dependent K(+) channel was confirmed as a binding target of TALA and 14-acetyl-TALA with high affinities. The online high throughput comparative CMC analysis method is suitable for screening specific active components from herbal medicines by increasing the specificity of screened results and can also be applied to other biological chromatography models.

  16. Nano-Particle Control of Void Formation and Expansion in Polymeric and Composite Systems

    National Research Council Canada - National Science Library

    Seferis, James C

    2006-01-01

    .... The most significant advancements and conclusions in this final report include interlayer modification of composites at the nanoscale and characterization of the interlayer behaviour of nanoparticle...

  17. Microstructure Characterization and Wear-Resistant Properties Evaluation of an Intermetallic Composite in Ni-Mo-Si System.

    Science.gov (United States)

    Huang, Boyuan; Song, Chunyan; Liu, Yang; Gui, Yongliang

    2017-02-04

    Intermetallic compounds have been studied for their potential application as structural wear materials or coatings on engineering steels. In the present work, a newly designed intermetallic composite in a Ni-Mo-Si system was fabricated by arc-melting process with commercially pure metal powders as starting materials. The chemical composition of this intermetallic composite is 45Ni-40Mo-15Si (at %), selected according to the ternary alloy diagram. The microstructure was characterized using optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS), and the wear-resistant properties at room temperature were evaluated under different wear test conditions. Microstructure characterization showed that the composite has a dense and uniform microstructure. XRD results showed that the intermetallic composite is constituted by a binary intermetallic compound NiMo and a ternary Mo₂Ni₃Si metal silicide phase. Wear test results indicated that the intermetallic composite has an excellent wear-resistance at room-temperature, which is attributed to the high hardness and strong atomic bonding of constituent phases NiMo and Mo₂Ni₃Si.

  18. A pH-, salt- and solvent-responsive carboxymethylcellulose-g-poly(sodium acrylate/medical stone superabsorbent composite with enhanced swelling and responsive properties

    Directory of Open Access Journals (Sweden)

    2011-05-01

    Full Text Available Free-radical graft copolymerization among sodium carboxymethylcellulose (CMC, partially neutralized acrylic acid (NaA, medical stone (MS and crosslinker N,N'-methylene-bis-acrylamide (MBA was performed to prepare new carboxymethylcellulose-g-poly(sodium acrylate/medical stone (CMC-g-PNaA/MS superabsorbent composites. Fourier transform infrared (FTIR spectra, thermogravimetry- differential scanning calorimetry (TG-DSC and field emission scanning electromicrsocopic (FESEM analysis confirmed that NaA had been grafted onto CMC backbone and MS participated in polymerization, and the thermal stability and surface morphologies were improved by the addition of MS. Energy dispersive spectrometer (EDS and elemental map (EM analyses revealed the better distribution of MS in the CMC-g-PNaA matrix. The incorporation of 20 wt% MS clearly enhanced the water absorption by 100% (from 317 to 634 g/g. The developed composites showed enhanced swelling rate and On-Off switching swelling characteristics in various pH solutions, saline solutions and hydrophilic organic solvents, which represented interesting and reversible pH-, saline- and hydrophilic organic solvent-responsive characteristics. In addition, the composite exhibited intriguing time-dependent kinetic swelling properties in various heavy metal solutions.

  19. Prostate cancer stem cell-targeted efficacy of a new-generation taxoid, SBT-1214 and novel polyenolic zinc-binding curcuminoid, CMC2.24.

    Directory of Open Access Journals (Sweden)

    Galina I Botchkina

    Full Text Available Prostate cancer is the second leading cause of cancer death among men. Multiple evidence suggests that a population of tumor-initiating, or cancer stem cells (CSCs is responsible for cancer development and exceptional drug resistance, representing a highly important therapeutic target. The present study evaluated CSC-specific alterations induced by new-generation taxoid SBT-1214 and a novel polyenolic zinc-binding curcuminoid, CMC2.24, in prostate CSCs.The CD133(high/CD44(high phenotype was isolated from spontaneously immortalized patient-derived PPT2 cells and highly metastatic PC3MM2 cells. Weekly treatment of the NOD/SCID mice bearing PPT2- and PC3MM3-induced tumors with the SBT-1214 led to dramatic suppression of tumor growth. Four of six PPT2 and 3 of 6 PC3MM2 tumors have shown the absence of viable cells in residual tumors. In vitro, SBT-1214 (100 nM-1 µM; for 72 hr induced about 60% cell death in CD133(high/CD44(+/high cells cultured on collagen I in stem cell medium (in contrast, the same doses of paclitaxel increased proliferation of these cells. The cytotoxic effects were increased when SBT-1214 was combined with the CMC2.24. A stem cell-specific PCR array assay revealed that this drug combination mediated massive inhibition of multiple constitutively up-regulated stem cell-related genes, including key pluripotency transcription factors. Importantly, this drug combination induced expression of p21 and p53, which were absent in CD133(high/CD44(high cells. Viable cells that survived this treatment regimen were no longer able to induce secondary spheroids, exhibited significant morphological abnormalities and died in 2-5 days.We report here that the SBT-1214 alone, or in combination with CMC2.24, possesses significant activity against prostate CD133(high/CD44(+/high tumor-initiating cells. This drug combination efficiently inhibits expression of the majority of stem cell-related genes and pluripotency transcription factors. In addition

  20. Validation of the scale system for PWR spent fuel isotopic composition analyses

    Energy Technology Data Exchange (ETDEWEB)

    Hermann, O.W.; Bowman, S.M.; Parks, C.V. [Oak Ridge National Lab., TN (United States); Brady, M.C. [Sandia National Laboratories, Las Vegas, NV (United States)

    1995-03-01

    The validity of the computation of pressurized-water-reactor (PWR) spent fuel isotopic composition by the SCALE system depletion analysis was assessed using data presented in the report. Radiochemical measurements and SCALE/SAS2H computations of depleted fuel isotopics were compared with 19 benchmark-problem samples from Calvert Cliffs Unit 1, H. B. Robinson Unit 2, and Obrigheim PWRs. Even though not exhaustive in scope, the validation included comparison of predicted and measured concentrations for 14 actinides and 37 fission and activation products. The basic method by which the SAS2H control module applies the neutron transport treatment and point-depletion methods of SCALE functional modules (XSDRNPM-S, NITAWL-II, BONAMI, and ORIGEN-S) is described in the report. Also, the reactor fuel design data, the operating histories, and the isotopic measurements for all cases are included in detail. The underlying radiochemical assays were conducted by the Materials Characterization. Center at Pacific Northwest Laboratory as part of the Approved Testing Material program and by four different laboratories in Europe on samples processed at the Karlsruhe Reprocessing Plant.