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Sample records for hybrid reinforcement system

  1. Scheduled power tracking control of the wind-storage hybrid system based on the reinforcement learning theory

    Science.gov (United States)

    Li, Ze

    2017-09-01

    In allusion to the intermittency and uncertainty of the wind electricity, energy storage and wind generator are combined into a hybrid system to improve the controllability of the output power. A scheduled power tracking control method is proposed based on the reinforcement learning theory and Q-learning algorithm. In this method, the state space of the environment is formed with two key factors, i.e. the state of charge of the energy storage and the difference value between the actual wind power and scheduled power, the feasible action is the output power of the energy storage, and the corresponding immediate rewarding function is designed to reflect the rationality of the control action. By interacting with the environment and learning from the immediate reward, the optimal control strategy is gradually formed. After that, it could be applied to the scheduled power tracking control of the hybrid system. Finally, the rationality and validity of the method are verified through simulation examples.

  2. Ductility Performance of Hybrid Fibre Reinforced Concrete

    OpenAIRE

    S. Eswari; P.N. Raghunath; Suguna, K

    2008-01-01

    This study presents a study on the ductility performance of hybrid fibre reinforced concrete. The influence of fibre content on the ductility performance of hybrid fibre reinforced concrete specimens having different fibre volume fractions was investigated. The parameters of investigation included modulus of rupture, ultimate load, service load, ultimate and service load deflection, crack width, energy ductility and deflection ductility. A total of 27 specimens, 100×100×500 mm, were tested to...

  3. Hybrid fiber reinforcement and crack formation in Cementitious Composite Materials

    DEFF Research Database (Denmark)

    Pereira, E.B.; Fischer, Gregor; Barros, J.A.O.

    2011-01-01

    reinforcement systems. The research described in this paper shows that the multi-scale conception of cracking and the use of hybrid fiber reinforcements do not necessarily result in an improved tensile behavior of the composite. Particular material design requirements may nevertheless justify the use of hybrid......- to the macroscale. In this study, the performance of different fiber reinforced cementitious composites is assessed in terms of their tensile stress-crack opening behavior. The results obtained from this investigation allow a direct quantitative comparison of the behavior obtained from the different fiber...

  4. Hybrid fiber reinforcement and crack formation in Cementitious Composite Materials

    DEFF Research Database (Denmark)

    Pereira, E.B.; Fischer, Gregor; Barros, J.A.O.

    2011-01-01

    reinforcement systems. The research described in this paper shows that the multi-scale conception of cracking and the use of hybrid fiber reinforcements do not necessarily result in an improved tensile behavior of the composite. Particular material design requirements may nevertheless justify the use of hybrid......The use of different types of fibers simultaneously for reinforcing cementitious matrices is motivated by the concept of a multi-scale nature of the crack propagation process. Fibers with different geometrical and mechanical properties are used to bridge cracks of different sizes from the micro......- to the macroscale. In this study, the performance of different fiber reinforced cementitious composites is assessed in terms of their tensile stress-crack opening behavior. The results obtained from this investigation allow a direct quantitative comparison of the behavior obtained from the different fiber...

  5. Ductility Performance of Hybrid Fibre Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    S. Eswari

    2008-01-01

    Full Text Available This study presents a study on the ductility performance of hybrid fibre reinforced concrete. The influence of fibre content on the ductility performance of hybrid fibre reinforced concrete specimens having different fibre volume fractions was investigated. The parameters of investigation included modulus of rupture, ultimate load, service load, ultimate and service load deflection, crack width, energy ductility and deflection ductility. A total of 27 specimens, 100×100×500 mm, were tested to study the above parameters. The specimens incorporated 0.0 to 2.0% volume fraction of polyolefin and steel fibres in different proportions. The ductility performance of hybrid fibre reinforced concrete specimens was compared with that of plain concrete. The test results show that addition of 2.0% by volume of hybrid fibres improves the ductility performance appreciably. An adaptive Neuro-Fuzzy based model has been proposed to predict the ductility performance characteristics. A reasonably close agreement has been obtained between the experimental and predicted results.

  6. HYBRID-SANDWICHED REINFORCEMENT WITH GEOSYNTHETICS

    Science.gov (United States)

    Yasuhara, Kazuya; Yamazaki, Shinji; Sakakibara, Tsutomu

    Advantageous aspects of sandwich-type reinforced earth structures combined with geosynthetics and sand mat are highlighted in this paper. Those aspects were elucidated by two kinds of laboratory tests : (1) large consolidation tests for improvement of hydraulic conductivity and (2) model footing tests on improvement of bearing capacity and deformation characteristics for reinforced earth structures, including both vertical permeability and horizontal transmissibility characteristics of geosynthetics results from both laboratory tests indicated the following: i) Hydraulic conductivity of geosynthetics used for this type of earth reinforcement can be maintained for a long period. Such conductivity sometimes disappears, particularly because of clogging when geosynthetics are adopted in embankment construction using fine-grained soils. This fact indicates that the sand mats which are laid above and beneath geosynthetics play a salient role in preventing clogging of geosynthetics that occurs by intrusion of fines from cohesive soils. ii) Sandwich-type reinforcement combined with geosynthetics and sand mats increases stability and decreases deformation of earth structures. In particular, the sandwich structure is effective for providing toughness, which has remained an important issue for reducing infrastructural maintenance and costs. In the later part of the paper, conventionally available stability analysis was carried out to propose the design procedure for reinforced earth structures and at the same time numerical analysis was also conducted to ensure the applicability of the hybrid-sandwiched earth reinforcement newly proposed in the current paper. Finally, based on the horizontal placement by means of HBS described in the current paper, the vertical drain procedure using the sandwich structures for accelerating consolidation and increasing stability of soft soils is also suggested for the future research and investigation.

  7. Hybrid fiber and nanopowder reinforced composites for wind turbine blades

    Directory of Open Access Journals (Sweden)

    Nikoloz M. Chikhradze

    2015-01-01

    Full Text Available The results of an investigation into the production of wind turbine blades manufactured using polymer composites reinforced by hybrid (carbon, basalt, glass fibers and strengthened by various nanopowders (oxides, carbides, borides are presented. The hybrid fiber-reinforced composites (HFRC were manufactured with prepreg technology by molding pre-saturated epoxy-strengthened matrix-reinforced fabric. Performance of the manufactured composites was estimated with values of the coefficient of operating condition (COC at a moderate and elevated temperature.

  8. Properties of glass/carbon fiber reinforced epoxy hybrid polymer composites

    Science.gov (United States)

    Patel, R. H.; Sevkani, V. R.; Patel, B. R.; Patel, V. B.

    2016-05-01

    Composite Materials are well known for their tailor-made properties. For the fabrication of composites different types of reinforcements are used for different applications. Sometimes for a particular application, one type of reinforcement may not fulfill the requirements. Therefore, more than one type of reinforcements may be used. Thus, the idea of hybrid composites arises. Hybrid composites are made by joining two or more different reinforcements with suitable matrix system. It helps to improve the properties of composite materials. In the present work glass/carbon fiber reinforcement have been used with a matrix triglycidyl ether of tris(m-hydroxy phenyl) phosphate epoxy resin using amine curing agent. Different physical and mechanical properties of the glass, carbon and glass/carbon fiber reinforced polymeric systems have been found out.

  9. [The systems process of reinforcement].

    Science.gov (United States)

    Sudakov, K V

    1996-01-01

    The process of reinforcement is considered in the context of the general theory of functional systems as an important part of behavioural act organization closely interacting with the dominant motivation. It is shown that reinforcement substantially changes the activities of separate neurons in different brain structures involved in dominant motivation. After a preliminary reinforcement under the influence of corresponding motivation the ribosomal apparatus of neurons begins to synthesize special molecular engrams of the action acceptor. The sensory mechanisms of reinforcement and, especially, the role of emotions are considered in details in the paper.

  10. Reinforced pericardium as a hybrid material for cardiovascular applications.

    Science.gov (United States)

    Bracaglia, Laura G; Yu, Li; Hibino, Narutoshi; Fisher, John P

    2014-11-01

    Pericardium-based cardiovascular devices are currently bound by a 10-year maximum lifetime due to detrimental calcification and degradation. The goal of this work is to develop a novel synthetic material to create a lasting replacement for malfunctioning or diseased tissue in the cardiovascular system. This study couples poly(propylene fumarate) (PPF) and a natural biomaterial together in an unprecedented hybrid composite and evaluates the composite versus the standard glutaraldehyde-treated tissue. The polymer reinforcement is hypothesized to provide initial physical protection from proteolytic enzymes and degradation, but leave the original collagen and elastin matrix unaltered. The calcification rate and durability of the hybrid material are evaluated in vitro and in an in vivo subdermal animal model. Results demonstrate that PPF is an effective support and leads to significantly less calcium deposition, important metrics when evaluating cardiovascular material. By avoiding chemical crosslinking of the tissue and associated side effects, PPF-reinforced pericardium as a biohybrid material offers a promising potential direction for further development in cardiovascular material alternatives. Eliminating the basis for the majority of cardiovascular prosthetic failures could revolutionize expectations for extent of cardiovascular repair.

  11. A systems process of reinforcement.

    Science.gov (United States)

    Sudakov, K V

    1997-01-01

    Functional systems theory was used to consider the process of reinforcement of the actions on the body of reinforcing factors, i.e., the results of behavior satisfying the body's original needs. The systems process of reinforcement includes reverse afferentation entering the CNS from receptors acted upon by various parameters of the desired results, and mechanisms for comparing reverse afferentation with the apparatus which accepts the results of the action and the corresponding emotional component. A tight interaction between reinforcement and the dominant motivation is generated on the basis of the hologram principle. Reinforcement forms an apparatus for predicting a desired result, i.e. a result-of-action acceptor. Reinforcement procedures significant changes in the activities of individual neurons in the various brain structures involved in dominant motivation, transforming their spike activity for a burst pattern to regular discharges; there are also molecular changes in neuron properties. After preliminary reinforcement, the corresponding motivation induces the ribosomal system of neurons to start synthesizing special effector molecules, which organize molecular engrams of the acceptor of the action's result. Sensory mechanisms of reinforcement are considered, with particular reference to the information role of emotions.

  12. Strength Evaluation of Steel-Nylon Hybrid Fibre Reinforced Concrete

    OpenAIRE

    Maniram Kumar; Er. Ankush Khadwal

    2014-01-01

    When fibres like steel, glass, polypropylene, nylon, carbon, aramid, polyester, jute, etc are mixed with concrete known as fibre reinforced concrete. To overcome the deficiencies of concrete; fibres are added to improve the performance of concrete. In this research hybrid reinforced concrete is made by using steel and nylon 6 fibres. The inclusion of both steel and nylon 6 fibres are used in order to combine the benefits of both fibers; structural improvements provided by stee...

  13. Single fiber pullout from hybrid fiber reinforced concrete

    NARCIS (Netherlands)

    Markovich, I.; Van Mier, J.G.M.; Walraven, J.C.

    2001-01-01

    Hybrid fiber reinforcement can be very efficient for improving the tensile response of the composite. In such materials, fibers of different geometries can act as bridging mechanisms over cracks of different widths. The fiber bridging efficiency depends on the interface properties, which makes inter

  14. Single Fibre Pullout from Hybrid Fiber Reinforced Concrete

    NARCIS (Netherlands)

    Markovich, I.; Van Mier, J.G.M.; Walraven, J.C.

    2001-01-01

    Hybrid fiber reinforcement can be very efficient for improving the tensile response of the composite. In such materials, fibers of different geometries can act as bridging mechanisms over cracks of different widths. The fiber bridging efficiency depends on the interface properties, which makes inter

  15. Mechanical Properties of Layered Hybrid Fiber Reinforced Concrete

    Institute of Scientific and Technical Information of China (English)

    YUAN Hai-qing; CHEN Jing-tao; ZHU Ji-dong

    2003-01-01

    To improve the mechanical properties of concrete,Layered Hybrid Fiber Reinforced Concrete (LHFRC) was developed in this paper.Through comparative tests,the effects of layered hybrid fibers on a series of mechanical properties of concrete were discussed.The mechanical properties include compressive strength,tensile strength,flexural strength,compressive stress-strain relationship,flexural toughness and cracking resistance of concrete.The testing results and analysis demonstrate that layered hybrid fibers can significantly improve the flexural strength,toughness and cracking resistance of concrete while the cost of concrete increases slightly.

  16. An Experimental Evaluation of Mechanical Properties of Hybrid Reinforcements

    Science.gov (United States)

    Sai Kumar, A.; Ganesan, G.; Karthikeyan, K.

    2017-07-01

    This paper presents the mechanical properties of unidirectional hybrid reinforcements formed from continuous fibres impregnated with a fibre binding material which are used for reinforcing the concrete. Recently FRP (Fibre Reinforced Polymer) manufacturers and suppliers have been increased all over the world because of the superior performance of FRP products in the construction industry. Its non-corrosive nature has turned the attention of many researchers to make several studies on different type of FRP products. Through a vast research, several standards also have been formulated. In this regard a new combination of FRP materials is tried in this paper and its properties have been derived. Carbon fibre and glass fibres fuse in this study to form a new hybrid rebar. The design properties such as tensile strength, tensile modulus, and compressive strength have been studied as per ASTM standards and it has been identified that the Hybrid rebar show a superior performance in comparison with GFRP (Glass FRP) and Steel rebars. This extraordinary performance of hybrid composite material increases the extensive engineering applications such as transport industry, aeronautics, naval, automotive industries.

  17. Evaluation of tensile strength of hybrid fiber (jute/gongura) reinforced hybrid polymer matrix composites

    Science.gov (United States)

    Venkatachalam, G.; Gautham Shankar, A.; Vijay, Kumar V.; Chandan, Byral R.; Prabaharan, G. P.; Raghav, Dasarath

    2015-07-01

    The polymer matrix composites attract many industrial applications due to its light weight, less cost and easy for manufacturing. In this paper, an attempt is made to prepare and study of the tensile strength of hybrid (two natural) fibers reinforced hybrid (Natural + Synthetic) polymer matrix composites. The samples were prepared with hybrid reinforcement consists of two different fibers such as jute and Gongura and hybrid polymer consists of polyester and cashew nut shell resins. The hybrid composites tensile strength is evaluated to study the influence of various fiber parameters on mechanical strength. The parameters considered here are the duration of fiber treatment, the concentration of alkali in fiber treatment and nature of fiber content in the composites.

  18. Computer modeling for investigating the stress-strainstate of beams with hybrid reinforcement

    Directory of Open Access Journals (Sweden)

    Rakhmonov Ahmadzhon Dzhamoliddinovich

    2014-01-01

    Full Text Available In this article the operation of a continuous double-span beam with hybrid reinforcement, steel and composite reinforcement under the action of concentrated forces is considered. The nature of stress-strain state of structures is investigated with the help of computer modeling using a three-dimensional model. Five models of beams with different characteristics were studied. According to the results of numerical studies the data on the distribution of stresses and displacements in continuous beams was provided. The dependence of the stress-strain state on increasing the percentage of the top reinforcement (composite of fittings and change in the concrete class is determined and presented in the article. Currently, the interest in the use of composite reinforcement as a working reinforcement of concrete structures in Russia has increased significantly, which is reflected in the increase of the number of scientific and practical publications devoted to the study of the properties and use of composite materials in construction, as well as emerging draft documents for design of such structures. One of the proposals for basalt reinforcement application is to use it in bending elements with combined reinforcement. For theoretical justification of the proposed nature of reinforcement and improvement of the calculation method the authors conduct a study of stress-strain state of continuous beams with the use of modern computing systems. The software program LIRA is most often used compared to other programs representing strain-stress state analysis of concrete structures.

  19. Fiber-reinforced bioactive and bioabsorbable hybrid composites

    Energy Technology Data Exchange (ETDEWEB)

    Huttunen, Mikko; Godinho, Pedro; Kellomaeki, Minna [Tampere University of Technology, Institute of Biomaterials, Hermiankatu 12, PO Box 589, FIN-33101 Tampere (Finland); Toermaelae, Pertti [Bioretec Ltd, Hermiankatu 22, PO Box 135, FI-33721 Tampere (Finland)], E-mail: mikko.huttunen@tut.fi

    2008-09-01

    Bioabsorbable polymeric bone fracture fixation devices have been developed and used clinically in recent decades to replace metallic implants. An advantage of bioabsorbable polymeric devices is that these materials degrade in the body and the degradation products exit via metabolic routes. Additionally, the strength properties of the bioabsorbable polymeric devices decrease as the device degrades, which promotes bone regeneration (according to Wolff's law) as the remodeling bone tissue is progressively loaded. The most extensively studied bioabsorbable polymers are poly-{alpha}-hydroxy acids. The major limitation of the first generation of bioabsorbable materials and devices was their relatively low mechanical properties and brittle behavior. Therefore, several reinforcing techniques have been used to improve the mechanical properties. These include polymer chain orientation techniques and the use of fiber reinforcements. The latest innovation for bioactive and fiber-reinforced bioabsorbable composites is to use both bioactive and bioresorbable ceramic and bioabsorbable polymeric fiber reinforcement in the same composite structure. This solution of using bioactive and fiber-reinforced bioabsorbable hybrid composites is examined in this study.

  20. Strength Evaluation of Steel-Nylon Hybrid Fibre Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Maniram Kumar

    2014-07-01

    Full Text Available When fibres like steel, glass, polypropylene, nylon, carbon, aramid, polyester, jute, etc are mixed with concrete known as fibre reinforced concrete. To overcome the deficiencies of concrete; fibres are added to improve the performance of concrete. In this research hybrid reinforced concrete is made by using steel and nylon 6 fibres. The inclusion of both steel and nylon 6 fibres are used in order to combine the benefits of both fibers; structural improvements provided by steel fibers and the resistance to plastic shrinkage improvements provided by nylon fibers. So the aim of this project is to investigate the mechanical properties (compressive strength, flexure strength and split tensile strength of hybrid fiber reinforced concrete under compression, flexure & tension. The total volume of fibre was taken 0.75 % of total volume of concrete. In this experimental work, four different concrete mix proportions were casted with fibres and one mix without fibres. Four different mix combinations of steel- nylon 6 fibres were 100-00%, 75-25%, 50-50% and 25-75%. Superplasticizer was used in all mixes to make concrete more workable. The results shown that compressive, split tensile and flexural strength of hybrid fibre reinforced concrete increase by increasing quantity of steel and nylon 6 fibres. The increase in compressive and tensile strength due to incorporation of steel fibre is greater than that of using nylon fibre. For the nylon 6 fibres, adding more fibres into the concrete has a limited improvement on splitting tensile strength. Inclusion of nylon 6 fibres along with steel fibres results in considerable improvement in flexural strength as compared to solo steel fibre.

  1. HYBRID VEHICLE CONTROL SYSTEM

    Directory of Open Access Journals (Sweden)

    V. Dvadnenko

    2016-06-01

    Full Text Available The hybrid vehicle control system includes a start–stop system for an internal combustion engine. The system works in a hybrid mode and normal vehicle operation. To simplify the start–stop system, there were user new possibilities of a hybrid car, which appeared after the conversion. Results of the circuit design of the proposed system of basic blocks are analyzed.

  2. Hybrid Action Systems

    DEFF Research Database (Denmark)

    Ronkko, Mauno; Ravn, Anders P.

    1997-01-01

    a differential action, which allows differential equations as primitive actions. The extension allows us to model hybrid systems with both continuous and discrete behaviour. The main result of this paper is an extension of such a hybrid action system with parallel composition. The extension does not change...... the original meaning of the parallel composition, and therefore also the ordinary action systems can be composed in parallel with the hybrid action systems....

  3. Hybrid intelligent engineering systems

    CERN Document Server

    Jain, L C; Adelaide, Australia University of

    1997-01-01

    This book on hybrid intelligent engineering systems is unique, in the sense that it presents the integration of expert systems, neural networks, fuzzy systems, genetic algorithms, and chaos engineering. It shows that these new techniques enhance the capabilities of one another. A number of hybrid systems for solving engineering problems are presented.

  4. Effect of hybrid fiber reinforcement on the cracking process in fiber reinforced cementitious composites

    DEFF Research Database (Denmark)

    Pereira, Eduardo B.; Fischer, Gregor; Barros, Joaquim A.O.

    2012-01-01

    The simultaneous use of different types of fibers as reinforcement in cementitious matrix composites is typically motivated by the underlying principle of a multi-scale nature of the cracking processes in fiber reinforced cementitious composites. It has been hypothesized that while undergoing...... tensile deformations in the composite, the fibers with different geometrical and mechanical properties restrain the propagation and further development of cracking at different scales from the micro- to the macro-scale. The optimized design of the fiber reinforcing systems requires the objective...... assessment of the contribution of each type of fiber to the overall tensile response. Possible synergistic effects resulting from particular combinations of fibers need to be clearly identified. In the present study, the evaluation of the response of different fiber reinforced cementitious composite...

  5. Analysis/design of strip reinforced random composites (strip hybrids)

    Science.gov (United States)

    Chamis, C. C.; Sinclair, J. H.

    1978-01-01

    Advanced analysis methods and composite mechanics were applied to a strip-reinforced random composite square panel with fixed ends to illustrate the use of these methods for the a priori assessment of the composite panel when subjected to complex loading conditions. The panel was assumed to be of E-glass random composite. The strips were assumed to be of three advanced unidirectional composites to cover a range of low, intermediate, and high modulus stiffness. The panels were assumed to be subjected to complex loadings to assess their adequacy as load-carrying members in auto body, aircraft engine nacelle and windmill blade applications. The results show that strip hybrid panels can be several times more structurally efficient than the random composite base materials. Some of the results are presented in graphical form and procedures are described for use of these graphs as guides for preliminary design of strip hybrids.

  6. Analysis/design of strip reinforced random composites /strip hybrids/

    Science.gov (United States)

    Chamis, C. C.; Sinclair, J. H.

    1978-01-01

    Results are described which were obtained by applying advanced analysis methods and composite mechanics to a strip-reinforced random composite square panel with fixed ends. This was done in order to illustrate the use of these methods for the apriori assessment of the composite panel when subjected to complex loading conditions. The panel was assumed to be of E-Glass/Random Composite. The strips were assumed to be of three advanced unidirectional composites to cover a range of low, intermediate, and high modulus stiffness. The panels were assumed to be subjected to complex loadings to assess their adequacy as load-carrying members in auto body, aircraft engine nacelle, and windmill blade applications. The results show that strip hybrid panels can be several times more structurally efficient than the random composite base materials. Some of the results are presented in graphical form and procedures are described for use of these graphs as guides for preliminary design of strip hybrids.

  7. Editorial: Hybrid Systems

    DEFF Research Database (Denmark)

    Olderog, Ernst-Rüdiger; Ravn, Anders Peter

    2007-01-01

    An introduction to three papers in a special issue on Hybrid Systems. These paper were first presented at an IFIP WG 2.2 meeting in Skagen 2005.......An introduction to three papers in a special issue on Hybrid Systems. These paper were first presented at an IFIP WG 2.2 meeting in Skagen 2005....

  8. Mechanical Behavior of Nanostructured Hybrids Based on Poly(Vinyl Alcohol/Bioactive Glass Reinforced with Functionalized Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    H. S. Mansur

    2012-01-01

    Full Text Available This study reports the synthesis and characterization of novel tridimensional porous hybrids based on PVA combined with bioactive glass and reinforced by chemically functionalized carbon nanotubes (CNT for potential use in bone tissue engineering. The functionalization of CNT was performed by introducing carboxylic groups in multiwall nanotubes. This process aimed at enhancing the affinity of CNTs with the water-soluble PVA polymer derived by the hydrogen bonds formed among alcohol (PVA and carboxylic groups (CNT–COOH. In the sequence, the CNT–COOH (0.25 wt% were used as the nanostructure modifier for the hybrid system based on PVA associated with the bioactive glass (BaG. The mechanical properties of the nanostructured hybrids reinforced with CNT–COOH were evaluated by axial compression tests, and they were compared to reference hybrid. The averaged yield stresses of macroporous hybrids were (2.3 ± 0.9 and (4.4 ± 1.0 MPa for the reference and the CNT reinforced materials, respectively. Moreover, yield strain and Young's modulus were significantly enhanced by about 30% for the CNT–COOH hybrids. Hence, as far as the mechanical properties are concerned, the results have clearly showed the feasibility of utilizing these new hybrids reinforced with functionalized CNT in repairing cancellous bone tissues.

  9. Hybrid systems with constraints

    CERN Document Server

    Daafouz, Jamal; Sigalotti, Mario

    2013-01-01

    Control theory is the main subject of this title, in particular analysis and control design for hybrid dynamic systems.The notion of hybrid systems offers a strong theoretical and unified framework to cope with the modeling, analysis and control design of systems where both continuous and discrete dynamics interact. The theory of hybrid systems has been the subject of intensive research over the last decade and a large number of diverse and challenging problems have been investigated. Nevertheless, many important mathematical problems remain open.This book is dedicated mainly to

  10. Studies on Effective Elastic Properties of CNT/Nano-Clay Reinforced Polymer Hybrid Composite

    Science.gov (United States)

    Thakur, Arvind Kumar; Kumar, Puneet; Srinivas, J.

    2016-02-01

    This paper presents a computational approach to predict elastic propertiesof hybrid nanocomposite material prepared by adding nano-clayplatelets to conventional CNT-reinforced epoxy system. In comparison to polymers alone/single-fiber reinforced polymers, if an additional fiber is added to the composite structure, it was found a drastic improvement in resultant properties. In this regard, effective elastic moduli of a hybrid nano composite are determined by using finite element (FE) model with square representative volume element (RVE). Continuum mechanics based homogenization of the nano-filler reinforced composite is considered for evaluating the volumetric average of the stresses and the strains under different periodic boundary conditions.A three phase Halpin-Tsai approach is selected to obtain the analytical result based on micromechanical modeling. The effect of the volume fractions of CNTs and nano-clay platelets on the mechanical behavior is studied. Two different RVEs of nano-clay platelets were used to investigate the influence of nano-filler geometry on composite properties. The combination of high aspect ratio of CNTs and larger surface area of clay platelets contribute to the stiffening effect of the hybrid samples. Results of analysis are validated with Halpin-Tsai empirical formulae.

  11. Flexural analysis of palm fiber reinforced hybrid polymer matrix composite

    Science.gov (United States)

    Venkatachalam, G.; Gautham Shankar, A.; Raghav, Dasarath; Santhosh Kiran, R.; Mahesh, Bhargav; Kumar, Krishna

    2015-07-01

    Uncertainty in availability of fossil fuels in the future and global warming increased the need for more environment friendly materials. In this work, an attempt is made to fabricate a hybrid polymer matrix composite. The blend is a mixture of General Purpose Resin and Cashew Nut Shell Liquid, a natural resin extracted from cashew plant. Palm fiber, which has high strength, is used as reinforcement material. The fiber is treated with alkali (NaOH) solution to increase its strength and adhesiveness. Parametric study of flexure strength is carried out by varying alkali concentration, duration of alkali treatment and fiber volume. Taguchi L9 Orthogonal array is followed in the design of experiments procedure for simplification. With the help of ANOVA technique, regression equations are obtained which gives the level of influence of each parameter on the flexure strength of the composite.

  12. for hybrid dynamical systems

    Directory of Open Access Journals (Sweden)

    Wassim M. Haddad

    2001-01-01

    Full Text Available In this paper we develop a unified dynamical systems framework for a general class of systems possessing left-continuous flows; that is, left-continuous dynamical systems. These systems are shown to generalize virtually all existing notions of dynamical systems and include hybrid, impulsive, and switching dynamical systems as special cases. Furthermore, we generalize dissipativity, passivity, and nonexpansivity theory to left-continuous dynamical systems. Specifically, the classical concepts of system storage functions and supply rates are extended to left-continuous dynamical systems providing a generalized hybrid system energy interpretation in terms of stored energy, dissipated energy over the continuous-time dynamics, and dissipated energy over the resetting events. Finally, the generalized dissipativity notions are used to develop general stability criteria for feedback interconnections of left-continuous dynamical systems. These results generalize the positivity and small gain theorems to the case of left-continuous, hybrid, and impulsive dynamical systems.

  13. Simultaneous thermal analysis and thermodilatometry of hybrid fiber reinforced UHPC

    Science.gov (United States)

    Scheinherrová, Lenka; Fořt, Jan; Pavlík, Zbyšek; Černý, Robert

    2017-07-01

    Development of concrete technology and the availability of variety of materials such as silica fume, mineral microfillers and high-range water-reducing admixtures make possible to produce Ultra-High Performance Concrete (UHPC) with compressive strength higher than 160 MPa. However, UHPC is prone to spall under high temperatures what limits its use for special applications only, such as offshore and marine structures, industrial floors, security barriers etc. The spalling is caused by the thermal stresses due to the temperature gradient during heating, and by the splitting force owing to the release of water vapour. Hybrid fibre reinforcement based on combination of steel and polymer fibres is generally accepted by concrete community as a functional solution preventing spalling. In this way, Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) is produced possessing high mechanical strength, durability and resistance to water and salt ingress. Since UHPFRC find use in construction industry in tunnel linings, precast tunnel segments, and high-rise buildings, its behaviour during the high-temperature exposure and its residual parameters are of the particular importance. On this account, Simultaneous Thermal Analysis (STA) and Thermodilatometry Analysis (TDA) were done in the paper to identify the structural and chemical changes in UHPFRC during its high-temperature load. Based on the experimental results, several physical and chemical processes that studied material underwent at high-temperatures were recognized. The obtained data revealed changes in the composition of the studied material and allowed identification of critical temperatures for material damage.

  14. Effect of Silane Treatment on Hybridized Use of Short Cellulose Fibers and Silica Particles for Natural Rubber Reinforcement

    Science.gov (United States)

    Lopattananon, Natinee; Jitkalong, Dolmalik; Seadan, Manus; Sakai, Tadamoto

    Processability, swelling and tensile properties of natural-rubber-based hybrid composites prepared by mixing short cellulose fibers and fine silica particles of equal contents with total loading of 20 phr using a two-roll mill were analyzed. Their properties were compared with those of natural rubber reinforced with single filler (silica or cellulose fiber) and corresponding unfilled natural rubber. The tensile test showed the reinforcing effect of both single filler system and hybrid filler system in relation to natural rubber. The tensile modulus and tensile strength of hybrid composites generally laid between those of fiber-reinforced and silica-reinforced natural rubber composites, whereas the elongation at break of hybrid composites was equal to that of single filler reinforcement system. The Mooney viscosity of silica-filled compound was much higher than that of unfilled natural rubber and short fiber-filled compounds, and was significantly reduced when hybridized fillers were used. Furthermore, a silane coupling agent, Si 69, was used to modify the surface properties of cellulose fibers and silica particles. Three microscopic evaluation techniques, that is, elemental X-ray mapping (EDX), 3D microfocus X-ray scanning, and N-ARC methods were applied to investigate the filler dispersion/mixing effects. It was found that both of the fillers were more homogeneously dispersed in the hybrid composites, and the affinity between the fillers and natural rubber was improved after the silane treatment. The results from this work suggested that the better dispersion of short cellulose fiber/silica hybrid fillers had great advantages in rubber processing, and allowed for equal or higher composite strength compared to a simply silica-filled composite system.

  15. Carbon nanotube reinforced hybrid composites: Computational modeling of environmental fatigue and usability for wind blades

    DEFF Research Database (Denmark)

    Dai, Gaoming; Mishnaevsky, Leon

    2015-01-01

    The potential of advanced carbon/glass hybrid reinforced composites with secondary carbon nanotube reinforcement for wind energy applications is investigated here with the use of computational experiments. Fatigue behavior of hybrid as well as glass and carbon fiber reinforced composites...... with the secondary CNT reinforcements (especially, aligned tubes) present superior fatigue performances than those without reinforcements, also under combined environmental and cyclic mechanical loading. This effect is stronger for carbon composites, than for hybrid and glass composites....... automatically using the Python based code. 3D computational studies of environment and fatigue analyses of multiscale composites with secondary nano-scale reinforcement in different material phases and different CNTs arrangements are carried out systematically in this paper. It was demonstrated that composites...

  16. Carbon nanotube reinforced hybrid composites: Computational modeling of environmental fatigue and usability for wind blades

    DEFF Research Database (Denmark)

    Dai, Gaoming; Mishnaevsky, Leon

    2015-01-01

    The potential of advanced carbon/glass hybrid reinforced composites with secondary carbon nanotube reinforcement for wind energy applications is investigated here with the use of computational experiments. Fatigue behavior of hybrid as well as glass and carbon fiber reinforced composites...... with and without secondary CNT reinforcement is simulated using multiscale 3D unit cells. The materials behavior under both mechanical cyclic loading and combined mechanical and environmental loading (with phase properties degraded due to the moisture effects) is studied. The multiscale unit cells are generated...... with the secondary CNT reinforcements (especially, aligned tubes) present superior fatigue performances than those without reinforcements, also under combined environmental and cyclic mechanical loading. This effect is stronger for carbon composites, than for hybrid and glass composites....

  17. Influence of Hybridizing Flax and Hemp-Agave Fibers with Glass Fiber as Reinforcement in a Polyurethane Composite

    Directory of Open Access Journals (Sweden)

    Pankaj Pandey

    2016-05-01

    Full Text Available In this study, six combinations of flax, hemp, and glass fiber were investigated for a hybrid reinforcement system in a polyurethane (PU composite. The natural fibers were combined with glass fibers in a PU composite in order to achieve a better mechanical reinforcement in the composite material. The effect of fiber hybridization in PU composites was evaluated through physical and mechanical properties such as water absorption (WA, specific gravity (SG, coefficient of linear thermal expansion (CLTE, flexural and compression properties, and hardness. The mechanical properties of hybridized samples showed mixed trends compared to the unhybridized samples, but hybridization with glass fiber reduced water absorption by 37% and 43% for flax and hemp-agave PU composites respectively.

  18. Hybrid Action Systems

    DEFF Research Database (Denmark)

    Rönnkö, M.; Ravn, Anders Peter; Sere, K.

    2003-01-01

    In this paper we investigate the use of action systems with differential actions in the specifcation of hybrid systems. As the main contribution we generalize the definition of a differential action, allowing the use of arbitrary relations over model variables and their time-derivatives in modell......In this paper we investigate the use of action systems with differential actions in the specifcation of hybrid systems. As the main contribution we generalize the definition of a differential action, allowing the use of arbitrary relations over model variables and their time...... parallel composition. Moreover, as the strength of the action system formalism is the support for stepwise development by refinement, we investigate refinement involving a differential action. We show that, due to the predicate transformer semantics, standard action refinement techniques apply also...... to the differential action, thus, allowing stepwise development of hybrid systems Udgivelsesdato: JAN 1...

  19. Optimization of woven jute/glass fibre-reinforced polyester hybrid composite solar parabolic trough collector

    Science.gov (United States)

    Reddy, K. S.; Singla, Hitesh

    2017-07-01

    In the present work, structural analysis of 5.77m × 4m woven jute (J)/glass (G) fibre-reinforced polyester hybrid composite solar parabolic trough is carried out based on trough parameters to obtain the minimum RMS local slope deviation, termed as SDx value under gravity loading. The optimization is done by varying parameters viz. direction and size of reinforced conduits, stacking number and sequence of hybrid trough laminate at fibre orientation of Δθ=45° and Δθ=60° amongst the layers at 0° collector angle. The analysis revealed that the configuration in which the conduits are placed in both X and Y directions is preferred over other configurations to scale down the effect of wind loads. Furthermore it has been observed that laminate of the order [0°G/45°G/-45°J/90°J]s undergoes minimum surface deformation amongst all the other configurations at conduit reinforcement in both X and Y directions for a conduit thickness of 0.75 mm and radius of 10 mm and obtains the overall SDx value of 1.3492 mrad. The results shows that proposed trough model is very promising and evolves a cost effective system.

  20. Mechanical Properties of Coir Rope-Glass Fibers Reinforced Polymer Hybrid Composites

    Directory of Open Access Journals (Sweden)

    B.Bakri

    2015-10-01

    Full Text Available Natural fiber composites have been developed and taken more attention in the last decades. Coir fiber is the natural fiber which has been used as reinforcement of composites. This fiber is hybridized with glass fiber for reinforcement composite. In this paper, coir rope and glass fibers were combined as reinforcement into hybrid composites with unsaturated polyester resin as matrix. The composition of fibers and matrix into hybrid composites are used 30:70 (volume fraction with unsaturated polyester. Volume fractions of coir rope mat and glass fiber mat in hybrid composites are 10:20, 15:15 and 20:10 respectively. The mechanical properties of the coir rope-glass fiber composite hybrid were described in this paper. Their properties include tensile strength, tensile modulus, flexural strength, flexural modulus, impact energy and impact strength. Fractography of tensile composite hybrid is also analyzed using Scanning Electron Microscope.

  1. Hybrid Effect Evaluation of Steel Fiber and Carbon Fiber on the Performance of the Fiber Reinforced Concrete

    OpenAIRE

    Weimin Song; Jian Yin

    2016-01-01

    Fiber reinforcement is an important method to enhance the performance of concrete. In this study, the compressive test and impact test were conducted, and then the hybrid effect between steel fiber (SF) and carbon fiber (CF) was evaluated by employing the hybrid effect index. Compressive toughness and impact toughness of steel fiber reinforced concrete (SFRC), carbon fiber reinforced concrete (CFRC) and hybrid fiber reinforced concrete (HFRC) were explored at steel fiber volume fraction 0.5%,...

  2. Influence of Carbon & Glass Fiber Reinforcements on Flexural Strength of Epoxy Matrix Polymer Hybrid Composites

    Directory of Open Access Journals (Sweden)

    T.D. Jagannatha

    2015-04-01

    Full Text Available Hybrid composite materials are more attracted by the engineers because of their properties like stiffness and high specific strength which leads to the potential application in the area of aerospace, marine and automobile sectors. In the present investigation, the flexural strength and flexural modulus of carbon and glass fibers reinforced epoxy hybrid composites were studied. The vacuum bagging technique was adopted for the fabrication of polymer hybrid composite materials. The hardness, flexural strength and flexural modulus of the hybrid composites were determined as per ASTM standards. The hardness, flexural strength and flexural modulus were improved as the fiber reinforcement contents increased in the epoxy matrix material.

  3. Reinforced Pericardium as a Hybrid Material for Cardiovascular Applications

    OpenAIRE

    Bracaglia, Laura G.; Yu, Li; Hibino, Narutoshi; Fisher, John P.

    2014-01-01

    Pericardium-based cardiovascular devices are currently bound by a 10-year maximum lifetime due to detrimental calcification and degradation. The goal of this work is to develop a novel synthetic material to create a lasting replacement for malfunctioning or diseased tissue in the cardiovascular system. This study couples poly(propylene fumarate) (PPF) and a natural biomaterial together in an unprecedented hybrid composite and evaluates the composite versus the standard glutaraldehyde-treated ...

  4. Mechanical and tribological studies on nano particles reinforced hybrid aluminum based composite

    Directory of Open Access Journals (Sweden)

    Muley Aniruddha V.

    2015-01-01

    Full Text Available Hybrid metal matrix composites are new class of materials due to their better mechanical properties which can be achieved through proper selection and combination of materials. The work reported in this paper is based on fabrication of hybrid composites by using nano particles as reinforcements. The hybrid composites were fabricated by reinforcing them with nano sized SiC and Al2O3 particles in order to study mechanical and tribological properties of these enhanced materials. A stir casting method was used to obtain hybrid composites. LM 6 aluminum alloy was used as a matrix material. The results shown increase in hardness as well as in ultimate tensile strength of the composites with small wt.% of nano-sized hybrid reinforcements. The composites produced also exhibit better tribological properties.

  5. Mechanical and electrical performance of Roystonea regia/glass fibre reinforced epoxy hybrid composites

    Indian Academy of Sciences (India)

    Govardhan Goud; R N Rao

    2012-08-01

    The present paper investigates mechanical and electrical properties of Roystonea regia/glass fibre reinforced epoxy hybrid composites. Five varieties of hybrid composites have been prepared by varying the glass fibre loading. Roystonea regia (royal palm), a natural fibre was collected from the foliage of locally available royal palm tree through the process of water retting and mechanical extraction. Roystonea regia, -glass short fibres were used together as reinforcement in epoxy matrix to form hybrid composites. It has been observed that tensile, flexural, impact and hardness properties of hybrid composites considerably increased with increase in glass fibre loading. But electrical conductivity and dielectric constant values decreased with increase in glass fibre content in the hybrid composites at all frequencies. Scanning electron microscopy of fractured hybrid composites has been carried out to study the fibre matrix adhesion.

  6. Hybrid Reinforced Concrete Frame Building with Pumice Brick Masonry Infill under Static Lateral Loading

    Directory of Open Access Journals (Sweden)

    Akmaluddin

    2012-08-01

    Full Text Available The purpose of this study is to investigate the behaviour of hybrid reinforced concrete frame with pumice brick masonry infill under static lateral loading. The term hybrid herein is referred to the frame composed of precast block masonry unit and cast in-place reinforced concrete beams. Parameters considered in this study were frame opening representing doors and windows commonly used in the wall system. Six types of frame namely FS, FB, FDE, FDC, FWE and FWC designation for solid frame, bare frame, frame with door opening at edge, frame with door opening at centre, frame with window opening at edge and frame with window opening at centre respectively were considered. Test results indicated that the FS has a maximum lateral strength greater than that of FB. The lateral strength of FS was about 3.68 of FB. The frames with various openings have lateral strength nearly 2.3 of lateral strength of the bare frame, FB. Ductility factor of the frames varied from 2.4 to 4.92. The residual strength of the frame with openings were varies between 2.33 and 3.35 of the bare frame. The stiffness of the infilled frames with opening were varied from 3.56 to 3.67 of the bare frame. The presence of openings in the infilled frame did not affect the frame stiffness considerably.

  7. Covercrete with hybrid functions - A novel approach to durable reinforced concrete structures

    Energy Technology Data Exchange (ETDEWEB)

    Tang, L.; Zhang, E.Q. [Chalmers University of Technology, SE-412 96 Gothenburg (Sweden); Fu, Y. [KTH Royal Institute of Technology, SE-106 91 Stockholm (Sweden); Schouenborg, B.; Lindqvist, J.E. [CBI Swedish Cement and Concrete Research Institute, c/o SP, Box 857, SE-501 15 Boraas (Sweden)

    2012-12-15

    Due to the corrosion of steel in reinforced concrete structures, the concrete with low water-cement ratio (w/c), high cement content, and large cover thickness is conventionally used for prolonging the passivation period of steel. Obviously, this conventional approach to durable concrete structures is at the sacrifice of more CO{sub 2} emission and natural resources through consuming higher amount of cement and more constituent materials, which is against sustainability. By placing an economically affordable conductive mesh made of carbon fiber or conductive polymer fiber in the near surface zone of concrete acting as anode we can build up a cathodic prevention system with intermittent low current density supplied by, e.g., the solar cells. In such a way, the aggressive negative ions such as Cl{sup -}, CO{sub 3}{sup 2-}, and SO{sub 4}{sup 2-} can be stopped near the cathodic (steel) zone. Thus the reinforcement steel is prevented from corrosion even in the concrete with relatively high w/c and small cover thickness. This conductive mesh functions not only as electrode, but also as surface reinforcement to prevent concrete surface from cracking. Therefore, this new type of covercrete has hybrid functions. This paper presents the theoretical analysis of feasibility of this approach and discusses the potential durability problems and possible solutions to the potential problems. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Exhaust System Reinforced by Jet Flow

    DEFF Research Database (Denmark)

    Pedersen, Lars Germann; Nielsen, Peter V.

    Since 1985 the University of Aalborg and Nordfab A/S have been working on an exhaust principle which is quite different from traditional exhaust systems. The REEXS principle (Reinforced Exhaust System), which originally was designed for the agricultural sector, is particularly well-suited for ind...

  9. Printed hybrid systems

    Science.gov (United States)

    Karioja, Pentti; Mäkinen, Jukka-Tapani; Keränen, Kimmo; Aikio, Janne; Alajoki, Teemu; Jaakola, Tuomo; Koponen, Matti; Keränen, Antti; Heikkinen, Mikko; Tuomikoski, Markus; Suhonen, Riikka; Hakalahti, Leena; Kopola, Pälvi; Hast, Jukka; Liedert, Ralf; Hiltunen, Jussi; Masuda, Noriyuki; Kemppainen, Antti; Rönkä, Kari; Korhonen, Raimo

    2012-04-01

    This paper presents research activities carried out at VTT Technical Research Centre of Finland in the field of hybrid integration of optics, electronics and mechanics. Main focus area in our research is the manufacturing of electronic modules and product structures with printed electronics, film-over-molding and polymer sheet lamination technologies and the goal is in the next generation of smart systems utilizing monolithic polymer packages. The combination of manufacturing technologies such as roll-to-roll -printing, injection molding and traditional component assembly is called Printed Hybrid Systems (PHS). Several demonstrator structures have been made, which show the potential of polymer packaging technology. One demonstrator example is a laminated structure with embedded LED chips. Element thickness is only 0.3mm and the flexible stack of foils can be bent in two directions after assembly process and was shaped curved using heat and pressure. The combination of printed flexible circuit boards and injection molding has also been demonstrated with several functional modules. The demonstrators illustrate the potential of origami electronics, which can be cut and folded to 3D shapes. It shows that several manufacturing process steps can be eliminated by Printed Hybrid Systems technology. The main benefits of this combination are small size, ruggedness and conformality. The devices are ideally suited for medical applications as the sensitive electronic components are well protected inside the plastic and the structures can be cleaned easily due to the fact that they have no joints or seams that can accumulate dirt or bacteria.

  10. Reinforcement learning with partitioning function system

    Institute of Scientific and Technical Information of China (English)

    李伟; 叶庆泰; 朱昌明

    2004-01-01

    The size of state-space is the limiting factor in applying reinforcement learning algorithms to practical cases. A reinforcement learning system with partitioning function (RLWPF) is established, in which statespace is partitioned into several regions. Inside the performance principle of RLWPF is based on a Semi-Markov decision process and has general significance. It can be applied to any reinforcement learning with a large statespace. In RLWPF, the partitioning module dispatches agents into different regions in order to decrease the state-space of each agent. This article proves the convergence of the SARSA algorithm for a Semi-Markov decision process, ensuring the convergence of RLWPF by analyzing the equivalence of two value functions in two Semi-Markov decision processes before and after partitioning. This article can show that the optimal policy learned by RLWPF is consistent with prior domain knowledge. An elevator group system is devised to decrease the average waiting time of passengers. Four agents control four elevator cars respectively. Based on RLWPF, a partitioning module is developed through defining a uniform round trip time as the partitioning criteria, making the wait time of most passengers more or less identical then elevator cars should only answer hall calls in their own region. Compared with ordinary elevator systems and reinforcement learning systems without partitioning module, the performance results show the advantage of RLWPF.

  11. Hybridity in Embedded Computing Systems

    Institute of Scientific and Technical Information of China (English)

    虞慧群; 孙永强

    1996-01-01

    An embedded system is a system that computer is used as a component in a larger device.In this paper,we study hybridity in embedded systems and present an interval based temporal logic to express and reason about hybrid properties of such kind of systems.

  12. PAN Nanofibers Reinforced with MMT/GO Hybrid Nanofillers

    Directory of Open Access Journals (Sweden)

    Qingqing Wang

    2014-01-01

    Full Text Available Single component nanofiller has shown some limitations in its performance, which can be overcome by hybrid nanofillers with two different components. In this work, montmorillonite (MMT/graphene oxide (GO hybrid nanofillers were formed by self-assembly and then incorporated into the polyacrylonitrile (PAN nanofibers by electrospinning process. X-ray diffraction (XRD, atomic force microscopy (AFM, and transmission electron microscopy (TEM were utilized to analyze the structures of MMT/GO hybrid nanofillers. And the effects of MMT/GO hybrid nanofillers on the morphology, thermal stability, and mechanical properties of PAN/MMT/GO composite nanofibrous membrane were examined by scanning electron microscopy (SEM, thermogravimetric analysis (TGA, and tensile test machine, respectively. The incorporation of MMT/GO hybrid nanofillers into PAN nanofibers showed a noticeable increase up to 30°C for the onset decomposition temperature and 1.32 times larger tensile strength than the pure PAN, indicating that the hybrid nanofiller is a promising candidate in improving thermal and mechanical properties of polymers.

  13. Behavior of Reinforced Hybrid Concrete Corbel-Column Connection with Vertical Construction Joint

    Directory of Open Access Journals (Sweden)

    Ammar Yasir Ali

    2017-03-01

    Full Text Available In this paper, shear behavior of reinforced hybrid concrete connection of corbel-column is experimentally investigated. Nine homogenous and hybrid concrete corbel-column connections subjected to vertical applied loads were constructed and tested within two test groups (A, B. The experimental program included the effect of several variables such as type of hybrid concrete;high strength concrete (HSC or steel fiber reinforced concrete (SFRC, monolithic casting of hybrid concrete connection, and presence of construction joint at the interface of corbel-column. Experimental results showed significant effects of concrete hybridization on the structural behavior of connection specimens such as: ultimate strength, cracking loads, cracking patterns, and failure modes. Hybridization process in group (A included hybrid connection of corbel-column with HSC or SFRC corbel instated of NSC. This process led to increase the capacity of connection by (26%, 38% and shear cracking loads by (20%, 120% respectively. Moreover, connections of hybrid concrete corbels cast monolithically improved the shear capacity of corbels by (19%, 42% for HSC or SFRC respectively. In group (B, presence of construction joint at connection region reduced the shear capacity of connectionsby (10% to 22% and cracking loads by (23%-62% compared with connections cast monolithically.

  14. Strength Modeling of High-Strength Concrete with Hybrid Fibre Reinforcement

    Directory of Open Access Journals (Sweden)

    A. Ravichandran

    2009-01-01

    Full Text Available The low tensile strength and limited ductility, the unavoidable deficiency, of concrete can be overcome by the addition of fibres. High strength concrete (HSC of 60 MPa containing hybrid fibres, combination of steel and polyolefin fibres, at different volume fraction of 0.5, 1.0, 1.5 and 2.0% were compared in terms of compressive, splitting tensile strength and flexural properties with HSC containing no fibres. Test results showed that the fibres when used in hybrid form could result in enhanced flexural toughness compared to steel fibre reinforced concrete [HSFRC]. The compressive strength of the fibre-reinforced concrete reached maximum at 1.5% volume fractions and the splitting tensile strength and modulus of rupture improved with increasing volume fraction. Strength models were established to predict the compressive and splitting tensile strength and modulus of rupture of the fibre-reinforced concrete. The models give prediction matching the measurements.

  15. Processing, structure and flexural strength of CNT and carbon fibre reinforced, epoxy-matrix hybrid composite

    Indian Academy of Sciences (India)

    K Chandra Shekar; M Sai Priya; P K Subramanian; Anil Kumar; B Anjaneya Prasad; N Eswara Prasad

    2014-05-01

    Advanced materials such as continuous fibre-reinforced polymer matrix composites offer significant enhancements in variety of properties, as compared to their bulk, monolithic counterparts. These properties include primarily the tensile stress, flexural stress and fracture parameters. However, till date, there are hardly any scientific studies reported on carbon fibre (Cf) and carbon nanotube (CNT) reinforced hybrid epoxy matrix composites (unidirectional). The present work is an attempt to bring out the flexural strength properties along with a detailed investigation in the synthesis of reinforced hybrid composite. In this present study, the importance of alignment of fibre is comprehensively evaluated and reported. The results obtained are discussed in terms of material characteristics, microstructure and mode of failure under flexural (3-point bend) loading. The study reveals the material exhibiting exceptionally high strength values and declaring itself as a material with high strength to weight ratio when compared to other competing polymer matrix composites (PMCs); as a novel structural material for aeronautical and aerospace applications.

  16. An Experimental Study on Hybrid Noncompression CF Bracing and GF Sheet Wrapping Reinforcement Method to Restore Damaged RC Structures

    Directory of Open Access Journals (Sweden)

    Kang Seok Lee

    2015-01-01

    Full Text Available We describe a novel technique for restoration of reinforced concrete (RC structures that have sustained damage during an earthquake. The reinforcement scheme described here is a hybrid seismic retrofitting technique that combines noncompression X-bracing using CF with externally bonded GF sheets to strengthen RC structures that have sustained damage following an earthquake. The GF sheet is used to improve the ductility of columns, and the noncompression CF X-bracing system, which consists of CF bracing and anchors to replace the conventional steel bracing and bolt connections, is used to increase the lateral strength of the framing system. We report seismic restoration capacity, which enables reuse of the damaged RC frames via the hybrid CF X-bracing and GF sheet wrapping system. Cyclic loading tests were carried out to investigate hysteresis of the lateral load-drift relations, as well as the ductility. The GF sheet significantly improved the ductility of columns, resulting in a change in failure mode. The strengthening effect of conventional CF sheets used in columns is not sufficient with respect to lateral strength and stiffness. However, this study results in a significant increase in the strength of the structure due to the use of CF X-bracing and inhibited buckling failure of the bracing. This result can be exploited to develop guidelines for the application of the reinforcement system to restore damaged RC structures.

  17. A reinforcement system and a method of reinforcing a structure with a tendon

    DEFF Research Database (Denmark)

    2016-01-01

    A reinforcement system for anchoring tendons for structural reinforcing a structure such as a concrete structure, said reinforcement system comprises at least one anchor and at least one tendon, said anchor is adapted to fix said tendon in and/or outside said structure, wherein said reinforcement...... system comprises a ductility element, which is positioned in structural connection between said tendon and said anchor, said ductility element comprising weakened deformation zones being deformable so that the length of the ductility is increased or decreased in an axial direction along the length...... of said tendon....

  18. Mechanical Behavior of Hybrid Glass/Steel Fiber Reinforced Epoxy Composites

    Directory of Open Access Journals (Sweden)

    Amanda K. McBride

    2017-04-01

    Full Text Available While conventional fiber-reinforced polymer composites offer high strength and stiffness, they lack ductility and the ability to absorb energy before failure. This work investigates hybrid fiber composites for structural applications comprised of polymer, steel fiber, and glass fibers to address this shortcoming. Varying volume fractions of thin, ductile steel fibers were introduced into glass fiber reinforced epoxy composites. Non-hybrid and hybrid composite specimens were prepared and subjected to monolithic and half-cyclic tensile testing to obtain stress-strain relationships, hysteresis behavior, and insight into failure mechanisms. Open-hole testing was used to assess the vulnerability of the composites to stress concentration. Incorporating steel fibers into glass/epoxy composites offered a significant improvement in energy absorption prior to failure and material re-centering capabilities. It was found that a lower percentage of steel fibers (8.2% in the hybrid composite outperformed those with higher percentages (15.7% and 22.8% in terms of energy absorption and re-centering, as the glass reinforcement distributed the plasticity over a larger area. A bilinear hysteresis model was developed to predict cyclic behavior of the hybrid composite.

  19. Hybrid radiator cooling system

    Science.gov (United States)

    France, David M.; Smith, David S.; Yu, Wenhua; Routbort, Jules L.

    2016-03-15

    A method and hybrid radiator-cooling apparatus for implementing enhanced radiator-cooling are provided. The hybrid radiator-cooling apparatus includes an air-side finned surface for air cooling; an elongated vertically extending surface extending outwardly from the air-side finned surface on a downstream air-side of the hybrid radiator; and a water supply for selectively providing evaporative cooling with water flow by gravity on the elongated vertically extending surface.

  20. Mechanical performance of oil palm empty fruit bunches/jute fibres reinforced epoxy hybrid composites

    Energy Technology Data Exchange (ETDEWEB)

    Jawaid, M. [School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia); Abdul Khalil, H.P.S., E-mail: akhalilhps@gmail.com [School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia); Abu Bakar, A. [School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2010-11-15

    Research highlights: {yields} Hybrid composites constituents of natural fibres show good mechanical performances. {yields} Hybridization with 20% jute fibre gives rise to sufficient modulus to composites. {yields} Outer or core material affect mechanical performance of hybrid composites. {yields} Impact strength of pure EFB composite is higher than hybrid composites. - Abstract: Oil palm empty fruit bunches (EFB)/jute fibre reinforced epoxy hybrid composites with different sequence of fibre mat arrangement such as EFB/jute/EFB and jute/EFB/jute were fabricated by hand lay-up method. The effect of layering patterns on the mechanical performance of the composites was studied. The hybrid composites are intended for engineering applications as an alternative to synthetic fibre composites. Mechanical performance of hybrid composites were evaluated and compared with the pure EFB, pure jute composites and neat epoxy using flexural and impact testing. The flexural properties of hybrid composite is higher than that of pure EFB composite with respect to the weight fraction of fibre, where as the impact strength of pure EFB composite is much higher than those of hybrid composites. The flexural results were interpreted using sandwich theory. The fracture surface morphology of the impact testing samples of the hybrid composites was performed by scanning electron microscopy (SEM).

  1. Chaotic Dynamics in Hybrid Systems

    NARCIS (Netherlands)

    P.J. Collins (Pieter)

    2008-01-01

    htmlabstractIn this paper we give an overview of some aspects of chaotic dynamics in hybrid systems, which comprise different types of behaviour. Hybrid systems may exhibit discontinuous dependence on initial conditions leading to new dynamical phenomena. We indicate how methods from topological

  2. Chaotic dynamics in hybrid systems

    NARCIS (Netherlands)

    P.J. Collins (Pieter)

    2008-01-01

    htmlabstractIn this paper we give an overview of some aspects of chaotic dynamics in hybrid systems, which comprise different types of behaviour. Hybrid systems may exhibit discontinuous dependence on initial conditions leading to new dynamical phenomena. We indicate how methods from topological

  3. Hybrid spread spectrum radio system

    Science.gov (United States)

    Smith, Stephen F [London, TN; Dress, William B [Camas, WA

    2010-02-09

    Systems and methods are described for hybrid spread spectrum radio systems. A method, includes receiving a hybrid spread spectrum signal including: fast frequency hopping demodulating and direct sequence demodulating a direct sequence spread spectrum signal, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

  4. Flexural, Impact Properties and Sem Analysis of Bamboo and Glass Fiber Reinforced Polyester Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Raghavendra Rao. H

    2014-08-01

    Full Text Available The Flexural, Impact properties and Scanning electron microscope analysis of Bamboo/glass fibers Reinforced polyester Hybrid composites were studied. The effect of alkali treatment of the bamboo fibers on these properties was also studied. It was observed that the Flexural, impact properties of the hybrid composite increase with glass fiber content. These properties found to be higher when alkali treated bamboo fibers were used in the hybrid composites. The elimination of amorphous hemi-cellulose with alkali treated leading to higher crystallinity of the bamboo fibers with alkali treatment may be responsible for these observations. The author investigated the interfacial bonding between Glass/Bamboo reinforced polyester composites. The effect of alkali treatment on the bonding between Glass/Bamboo composites was also studied.

  5. Evaluation of Hybrid Reinforcement (Fiber-Reinforced-Plastic Rod with Steel Core)

    Science.gov (United States)

    1993-08-01

    Kaci, S. (1992), "Cables Composites pour la Precontrainte : Etude de la Relaxation," Advanced Composite Materials in Bridges and Structures, 1st...Nishizaki, I., Sasaki, I. (1992), "Evaluation of the Durability of Advanced Composites for Applications to Prestressed Concrete Bridges ," Advanced...7:4 z ... ýs (*AA4 - 2-0 4 Theodor Krauthammer Professor of Civil Engineering ABSTRACT The corrosion of concrete reinforcement is a problem that

  6. Towards Modelling of Hybrid Systems

    DEFF Research Database (Denmark)

    Wisniewski, Rafal

    2006-01-01

    The article is an attempt to use methods of category theory and topology for analysis of hybrid systems. We use the notion of a directed topological space; it is a topological space together with a set of privileged paths. Dynamical systems are examples of directed topological spaces. A hybrid...... system consists of a number of dynamical systems that are glued together according to information encoded in the discrete part of the system. We develop a definition of a hybrid system as a functor from the category generated by a transition system to the category of directed topological spaces. Its...... directed homotopy colimit (geometric realization) is a single directed topological space. The behavior of hybrid systems can be then understood in terms of the behavior of dynamical systems through the directed homotopy colimit....

  7. Tribological performance of Graphene/Carbon nanotube hybrid reinforced Al2O3 composites

    Science.gov (United States)

    Yazdani, Bahareh; Xu, Fang; Ahmad, Iftikhar; Hou, Xianghui; Xia, Yongde; Zhu, Yanqiu

    2015-06-01

    Tribological performance of the hot-pressed pure Al2O3 and its composites containing various hybrid contents of graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs) were investigated under different loading conditions using the ball-on-disc method. Benchmarked against the pure Al2O3, the composite reinforced with a 0.5 wt% GNP exhibited a 23% reduction in the friction coefficient along with a promising 70% wear rate reduction, and a hybrid reinforcement consisting of 0.3 wt.% GNPs + 1 wt.% CNTs resulted in even better performance, with a 86% reduction in the wear rate. The extent of damage to the reinforcement phases caused during wear was studied using Raman spectroscopy. The wear mechanisms for the composites were analysed based on the mechanical properties, brittleness index and microstructural characterizations. The excellent coordination between GNPs and CNTs contributed to the excellent wear resistance property in the hybrid GNT-reinforced composites. GNPs played the important role in the formation of a tribofilm on the worn surface by exfoliation; whereas CNTs contributed to the improvement in fracture toughness and prevented the grains from being pulled out during the tribological test.

  8. Fabrication and evaluation of mechanical properties of alkaline treated sisal/hemp fiber reinforced hybrid composite

    Science.gov (United States)

    Venkatesha Gupta, N. S.; Akash; Sreenivasa Rao, K. V.; kumar, D. S. Arun

    2016-09-01

    Fiber reinforced polymer composite have acquired a dominant place in variety of applications because of higher specific strength and modulus, the plant based natural fiber are partially replacing currently used synthetic fiber as reinforcement for polymer composites. In this research work going to develop a new material which posses a strength to weight ratio that for exceed any of the present material. The hybrid composite sisal/hemp reinforced with epoxy matrix has been developed by compression moulding technique according to ASTM standards. Sodium hydroxide (NAOH) was used as alkali for treating the fibers. The amount of reinforcement was varied from 10% to 50% in steps of 10%. Prepared specimens were examined for mechanical properties such as tensile strength, flexural strength, and hardness. Hybrid composite with 40wt% sisal/hemp fiber were found to posses higher strength (tensile strength = 53.13Mpa and flexural strength = 82.07Mpa) among the fabricated hybrid composite specimens. Hardness value increases with increasing the fiber volume. Morphological examinations are carried out to analyze the interfacial characteristics, internal structure and fractured surfaces by using scanning electron microscope.

  9. Formal Description of Hybrid Systems

    DEFF Research Database (Denmark)

    Zhou, Chaochen; Ji, Wang; Ravn, Anders P.

    1996-01-01

    A language to describe hybrid systems, i.e. networks of communicating discrete and continuous processes, is proposed. A semantics of the language is given in Extended Duration Calculus, a real-time interval logic with a proof system that allows reasoning in mathematical analysis about continuous ...... processes to be embedded into the logic. The semantics thus provides a secure link to hybrid system models based on a general theory of dynamical systems....

  10. Hybrid spacecraft attitude control system

    Directory of Open Access Journals (Sweden)

    Renuganth Varatharajoo

    2016-02-01

    Full Text Available The hybrid subsystem design could be an attractive approach for futurespacecraft to cope with their demands. The idea of combining theconventional Attitude Control System and the Electrical Power System ispresented in this article. The Combined Energy and Attitude ControlSystem (CEACS consisting of a double counter rotating flywheel assemblyis investigated for small satellites in this article. Another hybrid systemincorporating the conventional Attitude Control System into the ThermalControl System forming the Combined Attitude and Thermal ControlSystem (CATCS consisting of a "fluid wheel" and permanent magnets isalso investigated for small satellites herein. The governing equationsdescribing both these novel hybrid subsystems are presented and theironboard architectures are numerically tested. Both the investigated novelhybrid spacecraft subsystems comply with the reference missionrequirements.The hybrid subsystem design could be an attractive approach for futurespacecraft to cope with their demands. The idea of combining theconventional Attitude Control System and the Electrical Power System ispresented in this article. The Combined Energy and Attitude ControlSystem (CEACS consisting of a double counter rotating flywheel assemblyis investigated for small satellites in this article. Another hybrid systemincorporating the conventional Attitude Control System into the ThermalControl System forming the Combined Attitude and Thermal ControlSystem (CATCS consisting of a "fluid wheel" and permanent magnets isalso investigated for small satellites herein. The governing equationsdescribing both these novel hybrid subsystems are presented and theironboard architectures are numerically tested. Both the investigated novelhybrid spacecraft subsystems comply with the reference missionrequirements.

  11. THERMOMECHANICAL PROPERTIES OF JUTE/BAGASSE HYBRID FIBRE REINFORCED EPOXY THERMOSET COMPOSITES

    Directory of Open Access Journals (Sweden)

    Sudhir Kumar Saw

    2009-11-01

    Full Text Available Natural fibres are partly replacing currently used synthetic fibres as reinforcement for polymer composites. Jute fibre bundles were high-cellulose-content modified by alkali treatment, while the bagasse fibre bundles were modified by creating quinones in the lignin portions of fibre surfaces and reacting them with furfuryl alcohol (FA to increase their adhesiveness. The effects of different fibre bundle loading and modification of bagasse fibre surfaces in hybrid fibre reinforced epoxy composites have been studied. The role of fibre/matrix interactions in chemically modified hybrid composites were investigated using Differential Scanning Calorimeter, Differential Thermo Gravimetry, and a Universal Tensile Machine and compared with those of unmodified bagasse fibre bundles incorporated with modified jute fibre bundles reinforced hybrid composites. Fibre surface modification reduced the hydrophilicity of fibre bundles, and significantly increased mechanical properties of hybrid composites were observed in conjunction with SEM images. The SEM analysis of the fibre and the composite fractured surfaces have confirmed the FA grafting and shown a better compatibility at the interface between chemically modified fibre bundles and epoxy resin. This paper incorporates interesting results of thermomechanical properties and evaluation of fibre/matrix interactions.

  12. Tribological Potential of Hybrid Composites Based on Zinc and Aluminium Alloys Reinforced with SiC and Graphite Particles

    Directory of Open Access Journals (Sweden)

    D. Džunić

    2012-12-01

    Full Text Available The paper reviews contemporary research in the area of hybrid composites based on zinc and aluminium alloys reinforced with SiC and graphite particles. Metal matrix composites (MMCs based on ZA matrix are being increasingly applied as light-weight and wear resistant materials. Aluminium matrix composites with multiple reinforcements (hybrid AMCsare finding increased applications because of improved mechanical and tribological properties and hence are better substitutes for single reinforced composites. The results of research show that the hybrid composites possess higher hardness, higher tensile strength, better wear resistance and lower coefficient of friction when compared to pure alloys.

  13. Study of Performance of Hybrid yarns (Hemp/ Polypropylene/ Glass Woven Reinforcements

    Directory of Open Access Journals (Sweden)

    Maris Manins

    2015-06-01

    Full Text Available This study examines the performance of reinforcements of 100 tex hemp yarns and hybrid yarns reinforcements with same hemp yarns and glass fibres’ (136 Tex in warp direction (25 % or 50 % interwoven with hemp yarns. The industrial loom CTБ-175 and craftsman’s loom, plain weaving technique for production of reinforcements with surface density in range of 91-246 g/m2 were used in the production. Tensile strength of hemp reinforcement on warp direction is 241.7N-279.8N and tensile modulus 218.48MPa-271.24MPa.The measurement of fabric thickness and physical-mechanical properties of reinforcements were carried out according to ISO 5084:1996 and LVS EN ISO 13934-1-2001 standards. One and two layer composites of woven reinforcements of hemp and polypropylene yarns were produced with Laboratory Press LP_S_50/SASTM. The surface density of one layer composite is 311.2 g/m2 and 608.4 g/m2 of two layers composite. The tensile strength of same composites is 303.1N and 599.5N, the tensile stress is 35.66 MPa and 40.65 MPa. The elastic modulus of one layer composites is 908.2 MPa and 1152.5MPa for two layers composite. The mechanical properties of composites were established according to ISO 527-5:2009 standard.

  14. Experimental investigation of fibre reinforced plastics with hybrid layups under high-velocity impact loads

    Directory of Open Access Journals (Sweden)

    Marco Romano

    2014-07-01

    Full Text Available This paper deals with experimental investigations concerning energy dissipation capacity of different kinds of reinforcement fibres in monolithic and hybrid layups under high-velocity impact loads. The investigated kinds of fibres are carbon, glass and basalt fibres. Therefore test panels, using the same thermoset resin, were built up and cured by autoclave processing. The fibre volume content of the test panels has been determined. Furthermore the influence of a separating layer at selected positions in the hybrid stacked panels was investigated. The results show the influence and the energy dissipation capacity of each single kind of fibre and the enhanced properties for the hybrid layups by hybrid stacking sequences and the use of a separating core material.

  15. Hybrid Composites Based on Carbon Fiber/Carbon Nanofilament Reinforcement

    Directory of Open Access Journals (Sweden)

    Mehran Tehrani

    2014-05-01

    Full Text Available Carbon nanofilament and nanotubes (CNTs have shown promise for enhancing the mechanical properties of fiber-reinforced composites (FRPs and imparting multi-functionalities to them. While direct mixing of carbon nanofilaments with the polymer matrix in FRPs has several drawbacks, a high volume of uniform nanofilaments can be directly grown on fiber surfaces prior to composite fabrication. This study demonstrates the ability to create carbon nanofilaments on the surface of carbon fibers employing a synthesis method, graphitic structures by design (GSD, in which carbon structures are grown from fuel mixtures using nickel particles as the catalyst. The synthesis technique is proven feasible to grow nanofilament structures—from ethylene mixtures at 550 °C—on commercial polyacrylonitrile (PAN-based carbon fibers. Raman spectroscopy and electron microscopy were employed to characterize the surface-grown carbon species. For comparison purposes, a catalytic chemical vapor deposition (CCVD technique was also utilized to grow multiwall CNTs (MWCNTs on carbon fiber yarns. The mechanical characterization showed that composites using the GSD-grown carbon nanofilaments outperform those using the CCVD-grown CNTs in terms of stiffness and tensile strength. The results suggest that further optimization of the GSD growth time, patterning and thermal shield coating of the carbon fibers is required to fully materialize the potential benefits of the GSD technique.

  16. Hybrid filler composition optimization for tensile strength of jute fibre-reinforced polymer composite

    Indian Academy of Sciences (India)

    ANURAG GUPTA; HARI SINGH; R SWALIA

    2016-09-01

    In present research work, pultrusion process is used to develop jute fibre-reinforced polyester (GFRP) composite and experiments have been performed on an indigenously developed pultrusion experimental setup. The developed composite consists of natural jute fibre as reinforcement and unsaturated polyester resin as matrix with hybrid filler containing bagasse fibre, carbon black and calcium carbonate (CaCO$_3$). The effect of weight content of bagasse fibre, carbon black and calcium carbonate on tensile strength of pultruded GFRP composite is evaluated and the optimum hybrid filler composition for maximizing the tensile strength is determined. Different compositions of hybrid filler are prepared by mixing three fillers using Taguchi L$_9$ orthogonal array. Fifteen percent of hybrid filler of different composition by weight was mixed in the unsaturated polyester resin matrix. Taguchi L$_9$ orthogonal array (OA) has been used to plan the experiments and ANOVA is used for analysing tensile strength. A regression model has also been proposed to evaluate the tensile strength of the composite within 7% error by varying the abovefillers weight. A confirmation experiment was performed which gives 73.14 MPa tensile strength of pultruded jute fibre polymer composite at the optimum composition of hybrid filler.

  17. Evaluation on mechanical properties of woven aloevera and sisal fibre hybrid reinforced epoxy composites

    Indian Academy of Sciences (India)

    A Shadrach Jeya Sekaran; K Palani Kumar; K Pitchandi

    2015-09-01

    Natural fibres as reinforcement in polymer composite for making low-cost materials are growing day by day. Researcher’s main attention is to apply appropriate technology to utilize these natural fibres as effectively and economically as possible to produce good quality fibre-reinforced polymer composites for various engineering applications. In this research, the experiments of tensile, flexural and impact tests were carried out for woven aloevera and sisal fibre hybrid-reinforced epoxy composites. The hand layup method of fabrication was employed in preparing the composites. The surface morphology of the composites was examined through scanning electron microscope. Due to the low-density and high-specific properties of sisal fibre composites, it offer cost savings when compared with synthetic fibres. Hence it has very good implications in the automotive and transportation industry.

  18. Examining of abrasion resistance of hybrid composites reinforced with SiC and Cgr particles

    Directory of Open Access Journals (Sweden)

    M. Łągiewka

    2008-08-01

    Full Text Available The presented work discusses the influence of the type and volume percentage of particulate reinforcement consisting of mixed silicon carbide and graphite on the abrasion wear of hybrid composites with AlMg10 matrix. Also the macro photos of frictional surfaces have been shown and the results of hardness measurements have been presented. The performed examinations have allowed for stating that the mixture of SiC and Cgr particles changes in favour the tribological properties of the matrix alloy. It has been also proved that introducing hard reinforcing particles along with soft lubricating ones allows for achieving the material exhibiting high abrasion resistance, and moreover, the graphite particles protect the abraded surface from the destructive action of silicon carbide particles. Also hardness measurements have been performed and the resulting conclusion is that the composite hardness increases with an increase in volume fraction of the reinforcing particles.

  19. Finite-Element Analysis of Jute- and Coir-Fiber-Reinforced Hybrid Composite Multipanel Plates

    Science.gov (United States)

    Nirbhay, M.; Misra, R. K.; Dixit, A.

    2015-09-01

    Natural-fiber-reinforced polymer composite materials are rapidly gaining interest worldwide both in terms of research and industrial applications. The present work includes the characterization and modeling of jute- and coir-fiber-reinforced hybrid composite materials. The mechanical behavior of a two-panel plate and a sixpanel box structure is analyzed under various loading regimes by using the finite-element software ABAQUS®. Exhaustive parametric studies are also performed to obtain a clear insight into the relationships between various parameters and deflections of the panels and stress distributions in them. Deflections of both the structures are compared and found to be in good agreement with published results. To determine the mechanical behavior of natural-fiber-reinforced composite panels, a finite-element analysis is performed.

  20. Hybrid-Vehicle Transmission System

    Science.gov (United States)

    Lupo, G.; Dotti, G.

    1985-01-01

    Continuously-variable transmission system for hybrid vehicles couples internal-combustion engine and electric motor section, either individually or in parallel, to power vehicle wheels during steering and braking.

  1. Hybrid-Vehicle Transmission System

    Science.gov (United States)

    Lupo, G.; Dotti, G.

    1985-01-01

    Continuously-variable transmission system for hybrid vehicles couples internal-combustion engine and electric motor section, either individually or in parallel, to power vehicle wheels during steering and braking.

  2. Pore pressure development in hybrid fibre-reinforced high strength concrete at elevated temperatures

    OpenAIRE

    Bangi, Mugume Rodgers; HORIGUCHI, Takashi

    2011-01-01

    The present experimental work investigates the build-up of pore pressure at different depths of High Strength Concrete (HSC) and Hybrid-Fibre-Reinforced High Strength Concrete (HFRHSC) when exposed to different heating rates. First, the effect of the measurement technique on maximum pore pressures measured was evaluated. The pressure measurement technique which utilized a sintered metal and silicon oil was found to be the most effective technique for pore pressure measurement. Pore pressure m...

  3. Hybrid solar lighting distribution systems and components

    Science.gov (United States)

    Muhs, Jeffrey D.; Earl, Dennis D.; Beshears, David L.; Maxey, Lonnie C.; Jordan, John K.; Lind, Randall F.

    2011-07-05

    A hybrid solar lighting distribution system and components having at least one hybrid solar concentrator, at least one fiber receiver, at least one hybrid luminaire, and a light distribution system operably connected to each hybrid solar concentrator and each hybrid luminaire. A controller operates all components.

  4. Hybrid solar lighting systems and components

    Science.gov (United States)

    Muhs, Jeffrey D.; Earl, Dennis D.; Beshears, David L.; Maxey, Lonnie C.; Jordan, John K.; Lind, Randall F.

    2007-06-12

    A hybrid solar lighting system and components having at least one hybrid solar concentrator, at least one fiber receiver, at least one hybrid luminaire, and a light distribution system operably connected to each hybrid solar concentrator and each hybrid luminaire. A controller operates each component.

  5. Model Reduction of Hybrid Systems

    DEFF Research Database (Denmark)

    Shaker, Hamid Reza

    systems are derived in this thesis. The results are used for output feedback control of switched nonlinear systems. Model reduction of piecewise affine systems is also studied in this thesis. The proposed method is based on the reduction of linear subsystems inside the polytopes. The methods which......High-Technological solutions of today are characterized by complex dynamical models. A lot of these models have inherent hybrid/switching structure. Hybrid/switched systems are powerful models for distributed embedded systems design where discrete controls are applied to continuous processes...... of hybrid systems, designing controllers and implementations is very high so that the use of these models is limited in applications where the size of the state space is large. To cope with complexity, model reduction is a powerful technique. This thesis presents methods for model reduction and stability...

  6. Effects of Hybrid Fibre Reinforcement on Fire Resistance Performance and Char Morphology of Intumescent Coating

    Directory of Open Access Journals (Sweden)

    Amir N.

    2016-01-01

    Full Text Available Recent researches of fire retardant intumescent coatings reinforced by single Rockwool and single glass wool fibre at various weight percentages and lengths showed some improvements to the mechanical properties of the coatings and the char produced. Therefore, in this research the fibres were combined together in intumescent coating formulation at several weight percentages and fibre lengths to study their effects towards fire resistance performance and char morphology. The hybrid fibre reinforced intumescent coatings were subjected to two types of fire tests; Bunsen burner at 1000°C and the electric furnace at 800°C for 1 hour, respectively. Steel temperature of the coated samples during Bunsen burner test was recorded to determine the fire resistance performance. Thermal stability of the intumescent coatings and chars was determined by Thermogravimetric Analysis (TGA. The morphology of the coatings and char was then examined by using Scanning Electron Microscopy (SEM and Energy Dispersive Spectrometry (EDS was conducted to obtain elemental composition of the samples. This research concluded that long-hybrid fibre at 12-mm length and 0.6% fibre-weight produced the top performing hybrid fibre intumescent formulation. The hybrid fibres form survived at elevated temperature, hence helped to provide structure and strengthen the char with the highest fire resistance was recorded at steel temperature of 197°C.

  7. A hybrid base isolation system

    Energy Technology Data Exchange (ETDEWEB)

    Hart, G.C. [Univ. of California, Los Angeles, CA (United States); Lobo, R.F.; Srinivasan, M. [Hart Consultant Group, Santa Monica, CA (United States); Asher, J.W. [kpff Engineers, Santa Monica, CA (United States)

    1995-12-01

    This paper proposes a new analysis procedure for hybrid base isolation buildings when considering the displacement response of a base isolated building to wind loads. The system is considered hybrid because of the presence of viscous dampers in the building above the isolator level. The proposed analysis approach incorporates a detailed site specific wind study combined with a dynamic nonlinear analysis of the building response.

  8. Ion-atom hybrid systems

    CERN Document Server

    Willitsch, Stefan

    2014-01-01

    The study of interactions between simultaneously trapped cold ions and atoms has emerged as a new research direction in recent years. The development of ion-atom hybrid experiments has paved the way for investigating elastic, inelastic and reactive collisions between these species at very low temperatures, for exploring new cooling mechanisms of ions by atoms and for implementing new hybrid quantum systems. The present lecture reviews experimental methods, recent results and upcoming developments in this emerging field.

  9. Reinforcement learning for port-hamiltonian systems.

    Science.gov (United States)

    Sprangers, Olivier; Babuška, Robert; Nageshrao, Subramanya P; Lopes, Gabriel A D

    2015-05-01

    Passivity-based control (PBC) for port-Hamiltonian systems provides an intuitive way of achieving stabilization by rendering a system passive with respect to a desired storage function. However, in most instances the control law is obtained without any performance considerations and it has to be calculated by solving a complex partial differential equation (PDE). In order to address these issues we introduce a reinforcement learning (RL) approach into the energy-balancing passivity-based control (EB-PBC) method, which is a form of PBC in which the closed-loop energy is equal to the difference between the stored and supplied energies. We propose a technique to parameterize EB-PBC that preserves the systems's PDE matching conditions, does not require the specification of a global desired Hamiltonian, includes performance criteria, and is robust. The parameters of the control law are found by using actor-critic (AC) RL, enabling the search for near-optimal control policies satisfying a desired closed-loop energy landscape. The advantage is that the solutions learned can be interpreted in terms of energy shaping and damping injection, which makes it possible to numerically assess stability using passivity theory. From the RL perspective, our proposal allows for the class of port-Hamiltonian systems to be incorporated in the AC framework, speeding up the learning thanks to the resulting parameterization of the policy. The method has been successfully applied to the pendulum swing-up problem in simulations and real-life experiments.

  10. Kekuatan transversa resin akrilik hybrid setelah penambahan glass fiber dengan metode berbeda (The transverse strength of the hybrid acrylic resin after glass fiber reinforcement with different method

    Directory of Open Access Journals (Sweden)

    Intan Nirwana

    2006-03-01

    Full Text Available Different types of fibers have been added to acrylic resin materials to improve their mechanical properties. The purpose of this study was to know the transverse strength of the hybrid acrylic resins after glass fiber reinforcement with difference method. This study used rectangular specimens of 65 mm in length, 10 mm in width and 2.5 mm in thickness. There were 3 groups consisting of 6 specimens each, hybrid acrylic resin without glass fiber (control, glass fibers dipped in methyl methacrylate monomer for 15 minutes before being reinforced into hybrid acrylic resin (first method, glass fibers reinforced into a mixture of polymer powder and monomer liquid after the hybrid acrylic resin was mixed directly (second method. All of the specimens were cured for 20 minutes at 100° C. Transverse strength was measured using Autograph. The statistical analyses using one way ANOVA and LSD test showed that there were significant differences in transverse strength (p < 0.05 among the groups. The means of transverse strength were 94,94; 118,27; and 116,34 MPa. It meant that glass fibers reinforcement into hybrid acrylic resin enhanced their transverse strength compared with control. Glass fiber reinforcement into hybrid acrylic resin with differenciate method didn’t enhance their transverse strength.

  11. Optimization and Static Stress Analysis of Hybrid Fiber Reinforced Composite Leaf Spring

    Directory of Open Access Journals (Sweden)

    Luay Muhammed Ali Ismaeel

    2015-01-01

    Full Text Available A monofiber reinforced composite leaf spring is proposed as an alternative to the typical steel one as it is characterized by high strength-to-weight ratio. Different reinforcing schemes are suggested to fabricate the leaf spring. The composite and the typical steel leaf springs are subjected to the same working conditions. A weight saving of about more than 60% can be achieved while maintaining the strength for the structures under consideration. The objective of the present study was to replace material for leaf spring. This study suggests various materials of hybrid fiber reinforced plastics (HFRP. Also the effects of shear moduli of the fibers, matrices, and the composites on the composites performance and responses are discussed. The results and behaviors of each are compared with each other and verified by comparison with analytical solution; a good convergence is found between them. The elastic properties of the hybrid composites are calculated using rules of mixtures and Halpin-Tsi equation through the software of MATLAB v-7. The problem is also analyzed by the technique of finite element analysis (FEA through the software of ANSYS v-14. An element modeling was done for every leaf with eight-node 3D brick element (SOLID185 3D 8-Node Structural Solid.

  12. 32 tesla hybrid magnet system

    Energy Technology Data Exchange (ETDEWEB)

    Leupold, M.J.; Iwasa, Y.; Weggel, R.J. (MIT Cambridge (U.S.A.))

    1984-01-01

    The paper describes the design and construction of a hybrid magnet system to generate 32T with 9MW of electrical power. The system consist of an 11T niobium-titanium superconducting magnet, a 1.8K/4.2K cryostat, and a high-performance, water-cooled Bitter magnet, all of which are discussed in the paper.

  13. Hybrid Effect Evaluation of Steel Fiber and Carbon Fiber on the Performance of the Fiber Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Weimin Song

    2016-08-01

    Full Text Available Fiber reinforcement is an important method to enhance the performance of concrete. In this study, the compressive test and impact test were conducted, and then the hybrid effect between steel fiber (SF and carbon fiber (CF was evaluated by employing the hybrid effect index. Compressive toughness and impact toughness of steel fiber reinforced concrete (SFRC, carbon fiber reinforced concrete (CFRC and hybrid fiber reinforced concrete (HFRC were explored at steel fiber volume fraction 0.5%, 1%, 1.5% and carbon fiber 0.1%, 0.2%, 0.3%. Results showed that the addition of steel fiber and carbon fiber can increase the compressive strength. SF, CF and the hybridization between them could increase the compressive toughness significantly. The impact test results showed that as the volume of fiber increased, the impact number of the first visible crack and the ultimate failure also increased. The improvement of toughness mainly lay in improving the crack resistance after the first crack. Based on the test results, the positive hybrid effect of steel fiber and carbon fiber existed in hybrid fiber reinforced concrete. The relationship between the compressive toughness and impact toughness was also explored.

  14. Effects of hybrid composition of LCP and glass fibres on abrasive wear of reinforced LLDPE

    Indian Academy of Sciences (India)

    S A R Hashmi; Ajay Naik; Navin Chand

    2006-02-01

    The hybrid of liquid crystalline polymer (LCP) fibres and glass fibres (GF) provide a combination of modulus and toughness to semi-crystalline linear-low-density-polyethylene (LLDPE). LCP and GF fibres reinforced composites were studied using two-body abrasion tester under different applied loads. Two sets of fibre reinforced LLDPE, 10 and 20 vol%, were investigated. The contents of LCP and glass fibres were varied as 25, 50, 75 and 100 vol% of overall volume of fibres in LLDPE. The effect of replacing glass fibre with LCP fibre on wear is reported. Wear loss increased with the applied loads and glass fibre contents in LLDPE. The replacements of glass fibres with LCP fibres improved abrasive wear resistance of composite. The composite containing 20 vol% of glass fibres in LLDPE showed the specific wear rate nearly double to that of LCP fibre reinforced LLDPE. Incorporation of LCP fibre improved wear resistance of glass fibre reinforced LLDPE. Worn surfaces were studied using SEM. Glass fibres were broken in small debris and removed easily whereas LCP fibres yielded to fibrillation during abrasive action. The overall wear rate was governed by the composition and test conditions.

  15. Reinforcement Learning in BitTorrent Systems

    CERN Document Server

    Izhak-Ratzin, Rafit; van der Schaar, Mihaela

    2010-01-01

    Recent research efforts have shown that the popular BitTorrent protocol does not provide fair resource reciprocation and may allow free-riding. In this paper, we propose a BitTorrent-like protocol that replaces the peer selection mechanisms in the regular BitTorrent protocol with a novel reinforcement learning (RL) based mechanism. Due to the inherent opration of P2P systems, which involves repeated interactions among peers over a long period of time, the peers can efficiently identify free-riders as well as desirable collaborators by learning the behavior of their associated peers. Thus, it can help peers improve their download rates and discourage free-riding, while improving fairness in the system. We model the peers' interactions in the BitTorrent-like network as a repeated interaction game, where we explicitly consider the strategic behavior of the peers. A peer, which applies the RL-based mechanism, uses a partial history of the observations on associated peers' statistical reciprocal behaviors to deter...

  16. Effect of increasingly metallized hybrid reinforcement on the wear mechanisms of magnesium nanocomposite

    Indian Academy of Sciences (India)

    S FIDA HASSAN; A M AL-QUTUB; S ZABIULLAH; K S TUN; M GUPTA

    2016-08-01

    Strength and ductility of pure magnesium have experienced simultaneous improvement due to the presence of nanosize hybrid (yttria and copper) reinforcement. Increasing the vol% (i.e., 0.3–1.0) of ductile metallic copper particles in reinforcement has further enhanced the strength of agnesium.Wear behaviour of these magnesium hybrid nanocomposites was investigated using pin-on-disc dry sliding tests against hardened tool steel using a constant sliding speed of 1ms$^{−1}$ under a range of loads from5 to 30 N for a sliding distance of 1000 m. Scanning electron microscopy identified abrasion and delamination as primary wear mechanisms in the hybrid nanocomposite.Oxidation was active in nanocomposite with higher copper content, tested under higher load and positively affected the wear resistance. Limited thermal softening was observed when tested at a relatively higher load. High frictional heat dissipation capacity couples with higher hardness resisted adhesive wear which is common mechanism for magnesium composite.

  17. Hybrid Systems: Computation and Control.

    Science.gov (United States)

    2007-11-02

    elbow) and a pinned first joint (shoul- der) (see Figure 2); it is termed an underactuated system since it is a mechanical system with fewer...Montreal, PQ, Canada, 1998. [10] M. W. Spong. Partial feedback linearization of underactuated mechanical systems . In Proceedings, IROS󈨢, pages 314-321...control mechanism and search for optimal combinations of control variables. Besides the nonlinear and hybrid nature of powertrain systems , hardware

  18. Advanced Hybrid Computer Systems. Software Technology.

    Science.gov (United States)

    This software technology final report evaluates advances made in Advanced Hybrid Computer System software technology . The report describes what...automatic patching software is available as well as which analog/hybrid programming languages would be most feasible for the Advanced Hybrid Computer...compiler software . The problem of how software would interface with the hybrid system is also presented.

  19. Mechanical properties of waste paper/jute fabric reinforced polyester resin matrix hybrid composites.

    Science.gov (United States)

    Das, Sekhar

    2017-09-15

    Hybrid composites were prepared with jute fabric and un-shredded newspaper in polyester resin matrix. The experiment was designed 1:2 weights ratio jute and unshredded newspaper to have 42 (w/w)% fibre content hybrid composites and two different sequences jute/paper/jute and paper/jute/paper of waste newspaper and jute fabric arrangement. Reinforcing material is characterized by chemically, X-ray diffraction methods, Fourier transform infrared spectroscopy and tensile testing. The tensile, flexural and interlaminar shear strength and fracture surface morphology of composites were evaluated and compared. It was found that tensile and flexural properties of the hybrid composite are higher than that of pure paper-based composite but less than pure woven jute composite. The hybridization effect of woven jute fabric and layering pattern effect on mechanical properties of newspaper/woven jute fabric hybrid composites were studied. The test results of composites were analyzed by one-way ANOVA (α=0.05), it showed significant differences among the groups. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Flexural Properties of E Glass and TR50S Carbon Fiber Reinforced Epoxy Hybrid Composites

    Science.gov (United States)

    Dong, Chensong; Sudarisman; Davies, Ian J.

    2013-01-01

    A study on the flexural properties of E glass and TR50S carbon fiber reinforced hybrid composites is presented in this paper. Specimens were made by the hand lay-up process in an intra-ply configuration with varying degrees of glass fibers added to the surface of a carbon laminate. These specimens were then tested in the three-point bend configuration in accordance with ASTM D790-07 at three span-to-depth ratios: 16, 32, and 64. The failure modes were examined under an optical microscope. The flexural behavior was also simulated by finite element analysis, and the flexural modulus, flexural strength, and strain to failure were calculated. It is shown that although span-to-depth ratio shows an influence on the stress-strain relationship, it has no effect on the failure mode. The majority of specimens failed by either in-plane or out-of-plane local buckling followed by kinking and splitting at the compressive GFRP side and matrix cracking combined with fiber breakage at the CFRP tensile face. It is shown that positive hybrid effects exist for the flexural strengths of most of the hybrid configurations. The hybrid effect is noted to be more obvious when the hybrid ratio is small, which may be attributed to the relative position of the GFRP layer(s) with respect to the neutral plane. In contrast to this, flexural modulus seems to obey the rule of mixtures equation.

  1. Modeling of geosynthetic reinforced capping systems

    Energy Technology Data Exchange (ETDEWEB)

    Viswanadham, B.V.S.; Koenig, D.; Jessberger, H.L. [Univ. of Bochum (Germany)

    1997-12-31

    The investigation deals with the influence of a geosynthetic reinforcement on the deformation behavior and sealing efficiency of the reinforced mineral sealing layer at the onset of non-uniform settlements. The research program is mainly concentrated in studying the influence of reinforcement inclusion in restraining cracks and crack propagation due to soil-geosynthetic bond efficiency. Centrifuge model tests are conducted in the 500 gt capacity balanced beam Bochum geotechnical Centrifuge (Z1) simulating a differential deformation of a mineral sealing layer of a landfill with the help of trap-door arrangement. By comparing the performance of the deformed mineral sealing layer with and without geogrid, the reinforcement ability of the geogrid in controlling the crack propagation and permeability of the mineral swing layer is evaluated.

  2. Hybrid Power Management System and Method

    Science.gov (United States)

    Eichenberg, Dennis J. (Inventor)

    2008-01-01

    A system and method for hybrid power management. The system includes photovoltaic cells, ultracapacitors, and pulse generators. In one embodiment, the hybrid power management system is used to provide power for a highway safety flasher.

  3. Dynamical systems revisited : Hybrid systems with Zeno executions

    OpenAIRE

    ZHANG, JUN; Johansson, Karl Henrik; Lygeros, John; Sastry, Shankar

    2000-01-01

    Results from classical dynamical systems are generalized to hybrid dynamical systems. The concept of omega limit set is introduced for hybrid systems and is used to prove new results on invariant sets and stability, where Zeno and non-Zeno hybrid systems can be treated within the same framework. As an example, LaSalle's Invariance Principle is extended to hybrid systems. Zeno hybrid systems are discussed in detail. The omega limit set of a Zeno execution is characterized for classes of hybrid...

  4. Reinforcement learning based backstepping control of power system oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Karimi, Ali; Eftekharnejad, Sara; Feliachi, Ali [Advanced Power and Electric Research Center (APERC), West Virginia University, Morgantown, WV 26506-6109 (United States)

    2009-11-15

    This paper proposes a reinforcement learning based backstepping control technique for damping oscillations in electric power systems using the generators excitation systems. Decentralized controllers are first designed using the backstepping technique. Then, reinforcement learning is used to tune the gains of these controllers to adapt to various operating conditions. Simulation results for a two area power system show that the proposed control technique provides better damping than (i) conventional power system stabilizers and (ii) backstepping fixed gain controllers. (author)

  5. Combinatorial Hybrid Systems

    DEFF Research Database (Denmark)

    Larsen, Jesper Abildgaard; Wisniewski, Rafal; Grunnet, Jacob Deleuran

    2008-01-01

    As initially suggested by E. Sontag, it is possible to approximate an arbitrary nonlinear system by a set of piecewise linear systems. In this work we concentrate on how to control a system given by a set of piecewise linear systems defined on simplices. By using the results of L. Habets and J. van...... Schuppen, it is possible to find a controller for the system on each of the simplices thus guaranteeing that the system flow on the simplex only will leave the simplex through a subset of its faces. Motivated by R. Forman, on the triangulated state space we define a combinatorial vector field, which...... indicates for a given face the future simplex. In the suggested definition we allow nondeterminacy in form of splitting and merging of solution trajectories. The combinatorial vector field gives rise to combinatorial counterparts of most concepts from dynamical systems, such as duals to vector fields, flow...

  6. Discrete fiber-reinforced polyurea systems for infrastructure strengthening and blast mitigation

    Science.gov (United States)

    Carey, Natalia L.

    The research presented in this dissertation focused on evaluating the effectiveness of various blast mitigation materials and coating technologies to be used for enhancing blast resistance of structural members. Mechanical properties and blast mitigation performance of different discrete fiber-reinforced polyurea (DFRP) systems were investigated through experimental and analytical work. Four technical papers discuss the research efforts conducted within this dissertation. The first paper examined the development and characterization of different DFRP systems for infrastructure strengthening and blast retrofit. The behavior of various systems which consisted of chopped E-glass fibers discretely integrated in with the polyurea matrix was evaluated through coupon tensile testing. The addition of glass fiber to a polymer coating provided improved stiffness and strength to the composite system while the polyurea base material provided ductility. The second paper evaluated the behavior of hybrid, plain, and steel fiber-reinforced concrete panels coated with various polyurea and DFRP systems under blast loading. Hybrid panels demonstrated higher blast mitigation performance compared to plain and steel fiber-reinforced concrete panels due to sacrificial hybrid layer. The addition of plain polyurea or DFRP systems on the tension side improved panel performance by containing fragmentation during a blast event. The third paper presents an analytical investigation conducted using the explicit finite element program LS-DYNA to model panel and coating response under blast loading. Several modeling solutions were undertaken and compared for concrete formulation. Modeling results were analyzed and compared to the experimental work to validate the conclusions. The final paper describes an internal equilibrium mechanics based model developed to predict the flexural capacity of reinforced concrete beams strengthened with various DFRP systems. The developed model was validated using

  7. Hybrid2 - The hybrid power system simulation model

    Energy Technology Data Exchange (ETDEWEB)

    Baring-Gould, E.I.; Green, H.J.; Dijk, V.A.P. van [National Renewable Energy Lab., Golden, CO (United States); Manwell, J.F. [Univ. of Massachusetts, Amherst, MA (United States)

    1996-12-31

    There is a large-scale need and desire for energy in remote communities, especially in the developing world; however the lack of a user friendly, flexible performance prediction model for hybrid power systems incorporating renewables hindered the analysis of hybrids as options to conventional solutions. A user friendly model was needed with the versatility to simulate the many system locations, widely varying hardware configurations, and differing control options for potential hybrid power systems. To meet these ends, researchers from the National Renewable Energy Laboratory (NREL) and the University of Massachusetts (UMass) developed the Hybrid2 software. This paper provides an overview of the capabilities, features, and functionality of the Hybrid2 code, discusses its validation and future plans. Model availability and technical support provided to Hybrid2 users are also discussed. 12 refs., 3 figs., 4 tabs.

  8. Experimental Test of Stainless Steel Wire Mesh and Aluminium Alloy With Glass Fiber Reinforcement Hybrid Composite

    Directory of Open Access Journals (Sweden)

    Ranga Raj R.,

    2015-05-01

    Full Text Available At present, composite materials are mostly used in aircraft structural components, because of their excellent properties like lightweight, high strength to weight ratio, high stiffness, and corrosion resistance and less expensive. In this experimental work, the mechanical properties of laminate, this is reinforced with stainless steel wire mesh, aluminum sheet metal, perforated aluminum sheet metal and glass fibers to be laminate and investigated. The stainless steel wire mesh and perforated aluminum metal were sequentially stacked to fabricate, hybrid composites. The aluminum metal sheet is also employed with that sequence to get maximum strength and less weight. The tensile, compressive and flexure tests carried out on the hybrid composite. To investigate the mechanical properties and elastic properties of the metal matrix composite laminate of a material we are using experimental test and theoretical calculation. The experimental work consists of Tensile, compressive and flexural test. The expectation of this project results in the tensile and compressive properties of this hybrid composite it is slightly lesser than carbon fibers but it could facilitate a weight reduction compared with CFRP panels. So this hybrid laminates composite material offering significant weight savings and maximum strength over some other GFRP conventional panels.

  9. Symbolic Algorithmic Analysis of Rectangular Hybrid Systems

    Institute of Scientific and Technical Information of China (English)

    Hai-Bin Zhang; Zhen-Hua Duan

    2009-01-01

    This paper investigates symbolic algorithmic analysis of rectangular hybrid systems. To deal with the symbolic reachability problem, a restricted constraint system called hybrid zone is formalized for the representation and manipulation of rectangular automata state-spaces. Hybrid zones are proved to be closed over symbolic reachability operations of rectangular hybrid systems. They are also applied to model-checking procedures for verifying some important classes of timed computation tree logic formulas. To represent hybrid zones, a data structure called difference constraint matrix is defined.These enable us to deal with the symbolic algorithmic analysis of rectangular hybrid systems in an efficient way.

  10. Thermal and Mechanical Behavior of Hybrid Polymer Nanocomposite Reinforced with Graphene Nanoplatelets

    Directory of Open Access Journals (Sweden)

    Minh-Tai Le

    2015-08-01

    Full Text Available In the present investigation, we successfully fabricate a hybrid polymer nanocomposite containing epoxy/polyester blend resin and graphene nanoplatelets (GNPs by a novel technique. A high intensity ultrasonicator is used to obtain a homogeneous mixture of epoxy/polyester resin and graphene nanoplatelets. This mixture is then mixed with a hardener using a high-speed mechanical stirrer. The trapped air and reaction volatiles are removed from the mixture using high vacuum. The hot press casting method is used to make the nanocomposite specimens. Tensile tests, dynamic mechanical analysis (DMA and thermogravimetric analysis (TGA are performed on neat, 0.2 wt %, 0.5 wt %, 1 wt %, 1.5 wt % and 2 wt % GNP-reinforced epoxy/polyester blend resin to investigate the reinforcement effect on the thermal and mechanical properties of the nanocomposites. The results of this research indicate that the tensile strength of the novel nanocomposite material increases to 86.8% with the addition of a ratio of graphene nanoplatelets as low as 0.2 wt %. DMA results indicate that the 1 wt % GNP-reinforced epoxy/polyester nanocomposite possesses the highest storage modulus and glass transition temperature (Tg, as compared to neat epoxy/polyester or the other nanocomposite specimens. In addition, TGA results verify thethermal stability of the experimental specimens, regardless of the weight percentage of GNPs.

  11. Behavior of hybrid high-strength fiber reinforced concrete slab-column connections under the effect of high tempera

    Directory of Open Access Journals (Sweden)

    Reham H. Ahmed

    2016-04-01

    Full Text Available Concrete can be modified to perform in a more ductile form by the addition of randomly distributed discrete fibers in the concrete matrix. The combined effect of the addition of two types of fibers (steel fiber and polypropylene fiber with different percentages to concrete matrix, which is called hybrid effect is currently under investigation worldwide. The current research work presents the conducted experimental program to observe the behavior of hybrid high strength reinforced concrete slab-column connections under the effect of high temperature. For this purpose, ten slab-column connections were casted and tested. The experimental program was designed to investigate the effect of different variables such as concrete mixture, column location and temperature fighting system. All specimens were exposed to a temperature of 500 °C for duration of two hours. To observe the effect of each variable, specimens were divided into four groups according to the studied parameters. The test results revealed that using hybrid high strength concrete HFHSC produced more strength in punching failure compared with high strength concrete HSC when exposed to elevated temperature. Fighting by air had higher initial crack load compared with that for without fighting and fighting by water. On the other hand, fighting by water decreased the ultimate load.

  12. Toughness enhancement in graphene nanoplatelet/SiC reinforced Al2O3 ceramic hybrid nanocomposites

    Science.gov (United States)

    Ahmad, Iftikhar; Islam, Mohammad; Subhani, Tayyab; Zhu, Yanqiu

    2016-10-01

    This paper elucidates the effect of silicon carbide nanoparticles (SiCNP) and graphene nanoplatelets (GNPs), on their own and together, on the densification behavior and fracture toughness of alumina (Al2O3) ceramic matrix. This was investigated by using the high-frequency induction heat sintering (HFIHS) process. While the addition of each nanostructure caused varying degrees of grain refinement and enhancement of mechanical properties, the incorporation of as little as 0.5 wt.% GNPs along with 5.0 wt.% SiCNP promoted uniform dispersion of the latter due to the lateral surface area of the graphene nanosheets with their two-dimensional morphology. There was an associated reduction in grain size from 1500 to 300 nm upon the addition of both types of nanoscale reinforcements. Extensive electron microscopy of the as-produced nanocomposites indicated the presence of SiCNP within, as well as at, the grain boundary areas whereas the 2D GNPs anchored between neighboring grains. Fractography of the samples revealed a transition from a mixed intergranular/transgranular mode for SiCNP or GNP-reinforced nanocomposites to transgranular fracture mode for the hybrid nanocomposites with improvements in fracture toughness and microhardness by 160 and 27%, respectively, largely due to the synergic role of the nanostructured reinforcements and their distinctly different toughening mechanisms. A new toughening model is proposed for the hybrid nanocomposites by taking into consideration crack deflection and pull-out effects due to SiCNP and the atomic level slip-stick driven GNPs inter-layer slithering. It was found that the addition of GNPs facilitates SiCNP dispersion that subsequently develops dense, fine-grained microstructures after a short-cycle, pressure-assisted consolidation process.

  13. Hot Extrusion of A356 Aluminum Metal Matrix Composite with Carbon Nanotube/Al2O3 Hybrid Reinforcement

    Science.gov (United States)

    Kim, H. H.; Babu, J. S. S.; Kang, C. G.

    2014-05-01

    Over the years, the attention of material scientists and engineers has shifted from conventional composite materials to nanocomposite materials for the development of light weight and high-performance devices. Since the discovery of carbon nanotubes (CNTs), many researchers have tried to fabricate metal matrix composites (MMCs) with CNT reinforcements. However, CNTs exhibit low dispersibility in metal melts owing to their poor wettability and large surface-to-volume ratio. The use of an array of short fibers or hybrid reinforcements in a preform could overcome this problem and enhance the dispersion of CNTs in the matrix. In this study, multi-walled CNT/Al2O3 preform-based aluminum hybrid composites were fabricated using the infiltration method. Then, the composites were extruded to evaluate changes in its mechanical properties. In addition, the dispersion of reinforcements was investigated using a hardness test. The required extrusion pressure of hybrid MMCs increased as the Al2O3/CNT fraction increased. The deformation resistance of hybrid material was over two times that of the original A356 aluminum alloy material due to strengthening by the Al2O3/CNTs reinforcements. In addition, an unusual trend was detected; primary transition was induced by the hybrid reinforcements, as can be observed in the pressure-displacement curve. Increasing temperature of the material can help increase formability. In particular, temperatures under 623 K (350 °C) and over-incorporating reinforcements (Al2O3 20 pct, CNTs 3 pct) are not recommended owing to a significant increase in the brittleness of the hybrid material.

  14. Sliding Wear Properties of Hybrid Aluminium Composite Reinforced by Particles of Palm Shell Activated Carbon and Slag

    Directory of Open Access Journals (Sweden)

    Zamri Yusoff

    2011-09-01

    Full Text Available In present work, dry sliding wear tests were conducted on hybrid composite reinforced with natural carbon based particles such as palm shell activated carbon (PSAC and slag. Hybrid composites containing 5 -20 wt.% of both reinforcements with average particles sizes about 125μm were prepared by conventional powder metallurgy technique, which involves the steps of mixing, compacting and sintering. Dry sliding experiments were conducted in air at room temperature using a pin-on-disc self-built attach to polisher machine. The disc which acted as the mating surface material was made of mild steel (120 HV cut from commercial mild steel sheet (2 mm thickness into 100mm diameter. The influence of the applied load was investigated under a constant sliding velocity of 0.1m/s with the applied loads at 3N, 11N and 51N. The contribution of the reinforcement content and the applied load as well as the sliding distance on the wear process and the wear rate have been investigated. The contribution of synergic factors such as applied load, sliding distance and reinforcement content (wt.% have been studied using analysis of variance (ANOVA. All synergic factors contribute to the wear process of all tested composites. Among synergic factors, the applied load is the highest contribution to wear process on both composites (Al/PSAC and Al/Slag and hybrid composite. The degree of improvement of wear resistance of hybrid composite is strongly dependent on the reinforcement content.

  15. The concept of a novel hybrid smart composite reinforced with radially aligned zigzag carbon nanotubes on piezoelectric fibers

    Science.gov (United States)

    Ray, M. C.

    2010-03-01

    A new hybrid piezoelectric composite (HPZC) reinforced with zigzag single-walled carbon nanotubes (CNTs) and piezoelectric fibers is proposed. The novel constructional feature of this composite is that the uniformly aligned CNTs are radially grown on the surface of piezoelectric fibers. A micromechanics model is derived to estimate the effective piezoelectric and elastic properties. It is found that the effective piezoelectric coefficient e31 of the proposed HPZC, which accounts for the in-plane actuation, is significantly higher than that of the existing 1-3 piezoelectric composite without reinforcement with carbon nanotubes and the previously reported hybrid piezoelectric composite (Ray and Batra 2009 ASME J. Appl. Mech. 76 034503).

  16. HYBRID SHEARWALL SYSTEM — SHEAR STRENGTH AT THE INTERFACE CONNECTION

    Directory of Open Access Journals (Sweden)

    Ulrich Wirth

    2013-12-01

    Full Text Available Based on a series of alternating, displacement-controlled load tests on ten one-third scale models, to study the behaviour of the interface of a hybrid shear wall system, it was proved that the concept of hybrid construction in earthquake prone regions is feasible. The hybrid shear-wall system consists of typical reinforced concrete shear walls with composite edge members or flanges. Ten different anchorage bar arrangements were developed and tested to evaluate the column-shearwall interface behaviour under cyclic shear forces acting along the interface between column and wall panel. Finite element models of the test specimens were developed that were capable of capturing the integrated concrete and reinforcing steel behaviour in the wall panels. Special models were  developed to capture the interface behaviour between the edge columns and the shear wall. A comparison between the experimental results and the numerical results shows excellent agreement, and clearly supports the validity of the model developed for predicting the non-linear response of the hybrid wall system under various load conditions.

  17. Hydrofluoric-nitric-sulphuric-acid surface treatment of tungsten for carbon fibre-reinforced composite hybrids in space applications

    Science.gov (United States)

    Kanerva, M.; Johansson, L.-S.; Campbell, J. M.; Revitzer, H.; Sarlin, E.; Brander, T.; Saarela, O.

    2015-02-01

    Hybrid material systems, such as combinations of tungsten foils and carbon fibre-reinforced plastic (CFRP), are replacing metal alloy concepts in spacecraft enclosures. However, a good adhesion between the tungsten oxide scale and the epoxy resin used is required. Here, the effects of a hydrofluoric-nitric-sulphuric-acid (HFNS) treatment on tungsten oxides and subsequent adhesion to CFRP are analysed using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and fracture testing. The work shows that HFNS treatment results in decreased oxygen content, over 50% thinner tungsten trioxide (WO3) layer and increased nano-roughness on thin tungsten foils. Fracture testing established a 39% increase in the average critical strain for tungsten-CFRP specimens after HFNS treatment was carried out on tungsten. The effect of the oxide scale modification regarding the critical strain energy release rate was ΔGc≈ 8.4 J/m2.

  18. Composite Strain Hardening Properties of High Performance Hybrid Fibre Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Vikram Jothi Jayakumar

    2014-01-01

    Full Text Available Hybrid fibres addition in concrete proved to be a promising method to improve the composite mechanical properties of the cementitious system. Fibre combinations involving different fibre lengths and moduli were added in high strength slag based concrete to evaluate the strain hardening properties. Influence of hybrid fibres consisting of steel and polypropylene fibres added in slag based cementitious system (50% CRL was explored. Effects of hybrid fibre addition at optimum volume fraction of 2% of steel fibres and 0.5% of PP fibres (long and short steel fibre combinations were observed in improving the postcrack strength properties of concrete. Test results also indicated that the hybrid steel fibre additions in slag based concrete consisting of short steel and polypropylene (PP fibres exhibited a the highest compressive strength of 48.56 MPa. Comparative analysis on the performance of monofibre concrete consisting of steel and PP fibres had shown lower residual strength compared to hybrid fibre combinations. Hybrid fibres consisting of long steel-PP fibres potentially improved the absolute and residual toughness properties of concrete composite up to a maximum of 94.38% compared to monofibre concrete. In addition, the relative performance levels of different hybrid fibres in improving the matrix strain hardening, postcrack toughness, and residual strength capacity of slag based concretes were evaluated systematically.

  19. Kenaf-glass fiber reinforced unsaturated polyester hybrid composites: Tensile properties

    Science.gov (United States)

    Zhafer, S. F.; Rozyanty, A. R.; Shahnaz, S. B. S.; Musa, L.; Zuliahani, A.

    2016-07-01

    The use of natural fibers in composite is rising in recent years due their lightweight, non-abrasive, combustible, non-toxic, low cost and biodegradable properties. However, in comparison with synthetic fibers, the mechanical properties of natural fibers are lower. Therefore, the inclusion of synthetic fibers could improve the mechanical performance of natural fiber based composites. In this study, kenaf bast fiber and glass fiber at different weight percentage loading were used as reinforcement to produce hybrid composites. Unsaturated polyester (UP) resin was used as matrix and hand lay-up process was performed to apply the UP resin on the hybrid kenaf bast/glass fiber composite. Effect of different fiber loading on tensile strength, tensile modulus and elongation at break of the hybrid composite was studied. It has been found that the highest value of tensile strength and modulus was achieved at 10 wt.% kenaf/10 wt.% glass fiber loading. It was concluded that addition of glass fiber has improved the tensile properties of kenaf bast fiber based UP composites.

  20. Evaluation of mechanical properties of natural hybrid fibers, reinforced polyester composite materials

    Directory of Open Access Journals (Sweden)

    S. Kasiviswanathan

    2015-12-01

    Full Text Available The composite materials are replacing the traditional materials, because of its superior properties such as high tensile strength, low thermal expansion, high strength to weight ratio. The developments of new materials are on the anvil and are growing day by day. In this work the effect of glass fibre hybridization with the randomly oriented natural fibers has been evaluated. The sisal (S, banana (B, E-glass synthetic fibers were chopped and reinforced with polyester matrix. Six layers were prepared in the following stacking sequence of S/B/G, S/G/B, G/S/B, G/S/B/G/S/B/G, S/G/B//S/G/B, B/G/S/B/G/S. The mechanical properties like impact strength, flexural strength and tensile strength were investigated and compared. It was observed that the addition of two and three layer of glass fiber can improve the mechanical properties like tensile, Flexural and impact strength.

  1. Synergetic Effects of Mechanical Properties on Graphene Nanoplatelet and Multiwalled Carbon Nanotube Hybrids Reinforced Epoxy/Carbon Fiber Composites

    OpenAIRE

    Pin-Ning Wang; Tsung-Han Hsieh; Chin-Lung Chiang; Ming-Yuan Shen

    2015-01-01

    Graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs) are novel nanofillers possessing attractive characteristics, including robust compatibility with most polymers, high absolute strength, and cost effectiveness. In this study, an outstanding synergetic effect on the grapheme nanoplatelets (GNPs) and multiwalled carbon nanotubes (CNTs) hybrids were used to reinforce epoxy composite and epoxy/carbon fiber composite laminates to enhance their mechanical properties. The mechanical propertie...

  2. IMPULSE CONTROL HYBRID ELECTRICAL SYSTEM

    Directory of Open Access Journals (Sweden)

    A. A. Lobaty

    2016-01-01

    Full Text Available This paper extends the recently introduced approach for modeling and solving the optimal control problem of fixedswitched mode DC-DC power converter. DCDC converters are a class of electric power circuits that used extensively in regulated DC power supplies, DC motor drives of different types, in Photovoltaic Station energy conversion and other applications due to its advantageous features in terms of size, weight and reliable performance. The main problem in controlling this type converters is in their hybrid nature as the switched circuit topology entails different modes of operation, each of it with its own associated linear continuous-time dynamics.This paper analyses the modeling and controller synthesis of the fixed-frequency buck DC-DC converter, in which the transistor switch is operated by a pulse sequence with constant frequency. In this case the regulation of the DC component of the output voltage is via the duty cycle. The optimization of the control system is based on the formation of the control signal at the output.It is proposed to solve the problem of optimal control of a hybrid system based on the formation of the control signal at the output of the controller, which minimizes a given functional integral quality, which is regarded as a linear quadratic Letov-Kalman functional. Search method of optimal control depends on the type of mathematical model of control object. In this case, we consider a linear deterministic model of the control system, which is common for the majority of hybrid electrical systems. For this formulation of the optimal control problem of search is a problem of analytical design of optimal controller, which has the analytical solution.As an example of the hybrid system is considered a step-down switching DC-DC converter, which is widely used in various electrical systems: as an uninterruptible power supply, battery charger for electric vehicles, the inverter in solar photovoltaic power plants.. A

  3. Genetic Scheduling and Reinforcement Learning in Multirobot Systems for Intelligent Warehouses

    Directory of Open Access Journals (Sweden)

    Jiajia Dou

    2015-01-01

    Full Text Available A new hybrid solution is presented to improve the efficiency of intelligent warehouses with multirobot systems, where the genetic algorithm (GA based task scheduling is combined with reinforcement learning (RL based path planning for mobile robots. Reinforcement learning is an effective approach to search for a collision-free path in unknown dynamic environments. Genetic algorithm is a simple but splendid evolutionary search method that provides very good solutions for task allocation. In order to achieve higher efficiency of the intelligent warehouse system, we design a new solution by combining these two techniques and provide an effective and alternative way compared with other state-of-the-art methods. Simulation results demonstrate the effectiveness of the proposed approach regarding the optimization of travel time and overall efficiency of the intelligent warehouse system.

  4. Hybrid slab-microchannel gel electrophoresis system

    Science.gov (United States)

    Balch, Joseph W.; Carrano, Anthony V.; Davidson, James C.; Koo, Jackson C.

    1998-01-01

    A hybrid slab-microchannel gel electrophoresis system. The hybrid system permits the fabrication of isolated microchannels for biomolecule separations without imposing the constraint of a totally sealed system. The hybrid system is reusable and ultimately much simpler and less costly to manufacture than a closed channel plate system. The hybrid system incorporates a microslab portion of the separation medium above the microchannels, thus at least substantially reducing the possibility of non-uniform field distribution and breakdown due to uncontrollable leakage. A microslab of the sieving matrix is built into the system by using plastic spacer materials and is used to uniformly couple the top plate with the bottom microchannel plate.

  5. Al6061 Hybrid Metal Matrix Composite Reinforced with Alumina and Molybdenum Disulphide

    Directory of Open Access Journals (Sweden)

    G. Pitchayyapillai

    2016-01-01

    Full Text Available Aluminum Hybrid Reinforcement Technology is a response to the dynamic ever-increasing service requirement of industries such as transportation, aerospace, automobile, and marine, due to its attractive properties like high ductility, highly conductivity, light weight, and high strength to weight ratio. In this evolution, an attempt has been made to investigate the wear rate of Al6061 hybrid metal matrix composite reinforced with the hard ceramic alumina (4, 8, and 12 wt.% of Al2O3 and soft solid lubricant of molybdenum disulphide (2, 4, and 6 wt.% of MoS2 is fabricated by using stir casting method. The unlubricated pins on disc wear tests were conducted to examine the wear behaviour of Al6061/12 wt.% of Al2O3/MoS2 composites. The sliding wear tests were carried out at various loads of 15, 30, and 45 N, sliding velocity (1.25, 2.50, and 3.25 m/sec, and different MoS2 wt.% (2, 4, and 6 wt.%. In addition, the CNC turning experiments were conducted on Al6061/12 wt.% Al2O3/6 wt.% MoS2 using CNMG 120408 uncoated carbide cutting tool under cutting of 100, 150, and 200 m/min, feed of 0.1, 0.2, and 0.3 mm/rev, and depth of cut of 1, 1.5, and 2 mm.

  6. Machinability Study of Hybrid Nanoclay-Glass Fibre Reinforced Polyester Composites

    Directory of Open Access Journals (Sweden)

    P. Prabhu

    2013-01-01

    Full Text Available Glass fibre reinforced polyester composites (GRP and hybrid nanoclay and glass fibre reinforced polyester nanocomposites (CGRP are fabricated by vacuum assisted resin infusion technique. The optimum mechanical properties are obtained for CGRP with 3 wt.% nanoclay. Three types of drills (carbide twist drill D 5407060, HSS twist drill BS-328, and HSS end mill (4 flutes “N”-type end mill RH-helical flute of 6 mm diameters are used to drill holes on GRP and CGRP. Three different speeds (600, 852, and 1260 rpm and two different feeds (0.045, 0.1 mm/rev are selected as process parameters. The effect of process parameter on thrust force and delamination during drilling CGRP is analyzed for optimizing the machining parameters. The delamination factor is low for the optimum process parameter (feed = 0.1 mm/rev and speed 852 rpm. Microstructural analysis confirms that at higher feeds, delamination is low for CGRP drilled with carbide tools. In order to analyze the effect of nanoclay in CGRP on tool wear, 200 holes were drilled on CGRP samples with 3 wt.% nanoclay, and the tool wear is analyzed under optimized parametric condition. Tool wear is high in HSS twist drill compared with carbide drill. The presence of nanoclay also accelerates the tool wear.

  7. Quantum technologies with hybrid systems.

    Science.gov (United States)

    Kurizki, Gershon; Bertet, Patrice; Kubo, Yuimaru; Mølmer, Klaus; Petrosyan, David; Rabl, Peter; Schmiedmayer, Jörg

    2015-03-31

    An extensively pursued current direction of research in physics aims at the development of practical technologies that exploit the effects of quantum mechanics. As part of this ongoing effort, devices for quantum information processing, secure communication, and high-precision sensing are being implemented with diverse systems, ranging from photons, atoms, and spins to mesoscopic superconducting and nanomechanical structures. Their physical properties make some of these systems better suited than others for specific tasks; thus, photons are well suited for transmitting quantum information, weakly interacting spins can serve as long-lived quantum memories, and superconducting elements can rapidly process information encoded in their quantum states. A central goal of the envisaged quantum technologies is to develop devices that can simultaneously perform several of these tasks, namely, reliably store, process, and transmit quantum information. Hybrid quantum systems composed of different physical components with complementary functionalities may provide precisely such multitasking capabilities. This article reviews some of the driving theoretical ideas and first experimental realizations of hybrid quantum systems and the opportunities and challenges they present and offers a glance at the near- and long-term perspectives of this fascinating and rapidly expanding field.

  8. Quantum technologies with hybrid systems

    Science.gov (United States)

    Kurizki, Gershon; Bertet, Patrice; Kubo, Yuimaru; Mølmer, Klaus; Petrosyan, David; Rabl, Peter; Schmiedmayer, Jörg

    2015-01-01

    An extensively pursued current direction of research in physics aims at the development of practical technologies that exploit the effects of quantum mechanics. As part of this ongoing effort, devices for quantum information processing, secure communication, and high-precision sensing are being implemented with diverse systems, ranging from photons, atoms, and spins to mesoscopic superconducting and nanomechanical structures. Their physical properties make some of these systems better suited than others for specific tasks; thus, photons are well suited for transmitting quantum information, weakly interacting spins can serve as long-lived quantum memories, and superconducting elements can rapidly process information encoded in their quantum states. A central goal of the envisaged quantum technologies is to develop devices that can simultaneously perform several of these tasks, namely, reliably store, process, and transmit quantum information. Hybrid quantum systems composed of different physical components with complementary functionalities may provide precisely such multitasking capabilities. This article reviews some of the driving theoretical ideas and first experimental realizations of hybrid quantum systems and the opportunities and challenges they present and offers a glance at the near- and long-term perspectives of this fascinating and rapidly expanding field. PMID:25737558

  9. Hybrid synchronization of hyperchaotic Lu system

    Indian Academy of Sciences (India)

    K Sebastian Sudheer; M Sabir

    2009-10-01

    In this paper, we study the hybrid synchronization between two identical hyperchaotic Lu systems. Hybrid synchronization of hyperchaotic Lu system is achieved through synchronization of two pairs of states and anti-synchronization of the other two pairs of states. Active controls are designed to achieve hybrid synchronization between drive and response systems using the sum and difference of relevant variables of the chaotic systems. Numerical simulations are presented to evaluate the analysis and effectiveness of the controllers.

  10. From hybrid-media system to hybrid-media politicians

    DEFF Research Database (Denmark)

    Eberholst, Mads Kæmsgaard; Ørsten, Mark; Burkal, Rasmus

    2017-01-01

    An increasingly complex hybrid system of social- and traditional-news media surrounds Nordic election campaigns as politically experienced incumbents favour traditional news media, and younger, lesser-known candidates’ social media. Despite little evidence for hybrid-media politicians, politicians......’ media use is changing rapidly; 15%–16% of Danish candidates used Twitter in 2011 but 68% in 2015. In this large-sample content analysis, party leaders have high traditional-news-media and low Twitter presence, and younger candidates visa-versa, but some politicians have high presence in both. Hybrid...

  11. Novel porous graphene oxide and hydroxyapatite nanosheets-reinforced sodium alginate hybrid nanocomposites for medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Guangyao [School of Mechanical and Electrical Engineering, East China Jiaotong University, Nanchang 330013 (China); Luo, Honglin [Research Institute of Biomaterials and Transportation, East China Jiaotong University, Nanchang 330013 (China); School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Key Laboratory of Advanced Ceramics and Machining Technology, Ministry of Education, Tianjin University, Tianjin 300072 (China); Zuo, Guifu [Hebei Provincial Key Laboratory of Inorganic Nonmetallic Materials, College of Materials Science and Engineering, Hebei United University, Tangshan 063009 (China); Ren, Kaijing [Department of Joint Surgery, Tianjin Hospital, Tianjin 300211 (China); Wan, Yizao, E-mail: yzwantju@126.com [Research Institute of Biomaterials and Transportation, East China Jiaotong University, Nanchang 330013 (China); School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Key Laboratory of Advanced Ceramics and Machining Technology, Ministry of Education, Tianjin University, Tianjin 300072 (China)

    2015-09-15

    Graphene oxide (GO) and hydroxyapatite (HAp) are frequently used as reinforcements in polymers to improve mechanical and biological properties. In this work, novel porous hybrid nanocomposites consisting of GO, HAp, and sodium alginate (SA) have been prepared by facile solution mixing and freeze drying in an attempt to obtain a scaffold with desirable mechanical and biological properties. The as-prepared porous GO/HAp/SA hybrid nanocomposites were characterized by SEM, XRD, FTIR, TGA, and mechanical testing. In addition, preliminary cell behavior was assessed by CCK8 assay. It is found that the GO/HAp/SA nanocomposites show improved compressive strength and modulus over neat SA and HAp/SA nanocomposites. CCK8 results reveal that the GO/HAp/SA nanocomposites show enhanced cell proliferation over neat SA and GO/SA nanocomposite. It has been demonstrated that GO/HAp20/SA holds promise in bone tissue engineering. - Graphical abstract: Display Omitted - Highlights: • Graphene oxide (GO), hydroxyapatite (HAp), and alginate (SA) nanocomposites were fabricated. • The novel porous composites were prepared by solution mixture and freeze drying. • The GO/HAp/SA had porous structure with porosity > 85% and pore size > 150 μm. • The GO/HAp/SA exhibited improved mechanical properties over HAp/SA counterparts. • The GO/HAp/SA showed enhanced cell proliferation over GO/SA counterparts.

  12. IJER@2014 Page 21 Prediction of Mechanical Properties of Hybrid Fiber Reinforced Polymer Composites

    Directory of Open Access Journals (Sweden)

    P Sivaraj

    2014-03-01

    Full Text Available Abstract— This work presents a systematic approach to evaluate and study the effect of process parameters on tensile flexural and impact strength of coir and bagasse fiber reinforced polyester-based hybrid composites and also predicts the properties of random oriented hybrid composites. The composite panel was fabricated using hand lay-up method to the size of 300mmx200mmx3mm with various weight percentage of natural fibers namely coir (10, 20 and 30 wt % and bagasse (10, 20 and 30 wt % combined with polyester resin. The mechanical properties testing such as tensile, flexural and impact strength were carried out for the samples cut from the fabricated composite panel to the dimensions as per ASTM standard. The significant contribution of mixing of fiber was determined by analysis of variance. The second-order polynomial curve fitting equations are modelled to predict the mechanical properties such as tensile, flexural and impact strength. Also scanning electron microscopy testing was conducted on tensile test specimen to find the fiber matrix interfacial adhesion.

  13. Mechanical Characterization and Water Absorption Behaviour of Interwoven Kenaf/PET Fibre Reinforced Epoxy Hybrid Composite

    Directory of Open Access Journals (Sweden)

    Yakubu Dan-mallam

    2015-01-01

    Full Text Available The development of interwoven fabric for composite production is a novel approach that can be adopted to address the challenges of balanced mechanical properties and water absorption behaviour of polymer composites. In this paper, kenaf and PET (polyethylene terephthalate fibre were selected as reinforcing materials to develop the woven fabric, and low viscosity epoxy resin was chosen as the matrix. Vacuum infusion process was adopted to produce the hybrid composite due to its superior advantages over hand lay-up technique. The weight percentage composition of the Epoxy/kenaf/PET hybrid composite was maintained at 70/15/15 and 60/20/20, respectively. A significant increase in tensile strength and elastic modulus of approximately 73% and 53% was recorded in relation to neat epoxy. Similarly, a substantial increase in flexural, impact, and interlaminar properties was also realized in relation to neat epoxy. This enhancement in mechanical properties may be attributed to the interlocking structure of the interwoven fabric, individual properties of kenaf and PET fibres, strong interfacial bonding, and resistance of the fibres to impact loading. The water absorption of the composites was studied by prolonged exposure in distilled water, and the moisture absorption pattern was found to follow Fickian behaviour.

  14. Preparation and Properties of Polymer/Vermiculite Hybrid Superabsorbent Reinforced by Fiber for Enhanced Oil Recovery

    Directory of Open Access Journals (Sweden)

    Fayang Jin

    2014-01-01

    Full Text Available A series of polymer/clay hybrid superabsorbent composites (SACFs comprising acrylamide, acrylic acid, sodium 2-acrylamido-tetradecyl sulfonate, fiber, and vermiculite by in situ intercalation and exfoliated method was successfully synthesized. The structure of SACFs was characterized by IR, SXRD, and SEM measurements. Much notable absorbency for SACF-2 was observed compared to that for SACF-1 in the absence of hydrophobic group in the high cationic solution due to the alkyl carbon chain and sulfonic acid group of hydrophobic moistures protecting the cations from attacking the carboxylate groups. What is more, high temperature fiber which acts as bridge connection for the polymeric network structure enhanced both toughness and strength for SACF-4 in the harsh conditions. At the total dissolved substance of 212000 mg/L for Tarim Basin injected water and the temperature of 120°C, desired absorbency as well as water retaining property for SACF-4 was observed during the long period of thermal ageing. Core flooding experiments demonstrated that SACFs could migrate as amoeba in the porous medium and accumulated in the narrow channel to adjust injection profile, promoting the subsequent water diverting into the unswept zones. Finally, characteristic parameters for SACFs calculated from flooding experiment further confirmed these polymer/clay hybrid composites reinforced by fiber would have robust application in the mature oilfield for profile control.

  15. Control for a class of hybrid systems

    NARCIS (Netherlands)

    J.H. van Schuppen (Jan)

    1997-01-01

    textabstractA hybrid control system is a control theoretic model for a computer controlled engineering system. A definition of a hybrid control system is formulated that consists of a product of a finite state automaton and of a family of continuous control systems. An example of a transportation

  16. Solar-geothermal hybrid system

    Energy Technology Data Exchange (ETDEWEB)

    Lentz, Alvaro; Almanza, Rafael [Instituto de Ingenieria, UNAM, Ciudad Universitaria, Edificio 12, 04510 Mexico DF (Mexico)

    2006-10-15

    The Cerro Prieto Geothermal Power Plant is located in the northwest of Mexico, lat. 32{sup o}39', long. 115{sup o}21' in the northern hemisphere. A solar-geothermal hybrid system is proposed in order to increase the steam flow during the present geothermal cycle, adding a solar field of parabolic trough concentrators. Energy is supplied to the geothermal flow from wells in order to increase the steam generation rate. This configuration will increase the capacity factor of the system by generating additional steam during the peak demand hours. The parabolic trough solar field is evaluated in North-South and East-West orientation collector alignments. A proposal to obtain an increase of 10% in steam flow is evaluated, as the increase in flow is limited by the content of dissolved salts, so as to avoid a liquid phase with high salt concentrations. The size of the parabolic troughs field was obtained. (author)

  17. Consensus of Hybrid Multi-Agent Systems.

    Science.gov (United States)

    Zheng, Yuanshi; Ma, Jingying; Wang, Long

    2017-01-27

    In this brief, we consider the consensus problem of hybrid multiagent systems. First, the hybrid multiagent system is proposed, which is composed of continuous-time and discrete-time dynamic agents. Then, three kinds of consensus protocols are presented for the hybrid multiagent system. The analysis tool developed in this brief is based on the matrix theory and graph theory. With different restrictions of the sampling period, some necessary and sufficient conditions are established for solving the consensus of the hybrid multiagent system. The consensus states are also obtained under different protocols. Finally, simulation examples are provided to demonstrate the effectiveness of our theoretical results.

  18. Hybrid Dynamical Systems Modeling, Stability, and Robustness

    CERN Document Server

    Goebel, Rafal; Teel, Andrew R

    2012-01-01

    Hybrid dynamical systems exhibit continuous and instantaneous changes, having features of continuous-time and discrete-time dynamical systems. Filled with a wealth of examples to illustrate concepts, this book presents a complete theory of robust asymptotic stability for hybrid dynamical systems that is applicable to the design of hybrid control algorithms--algorithms that feature logic, timers, or combinations of digital and analog components. With the tools of modern mathematical analysis, Hybrid Dynamical Systems unifies and generalizes earlier developments in continuous-time and discret

  19. Stochastic Reachability Analysis of Hybrid Systems

    CERN Document Server

    Bujorianu, Luminita Manuela

    2012-01-01

    Stochastic reachability analysis (SRA) is a method of analyzing the behavior of control systems which mix discrete and continuous dynamics. For probabilistic discrete systems it has been shown to be a practical verification method but for stochastic hybrid systems it can be rather more. As a verification technique SRA can assess the safety and performance of, for example, autonomous systems, robot and aircraft path planning and multi-agent coordination but it can also be used for the adaptive control of such systems. Stochastic Reachability Analysis of Hybrid Systems is a self-contained and accessible introduction to this novel topic in the analysis and development of stochastic hybrid systems. Beginning with the relevant aspects of Markov models and introducing stochastic hybrid systems, the book then moves on to coverage of reachability analysis for stochastic hybrid systems. Following this build up, the core of the text first formally defines the concept of reachability in the stochastic framework and then...

  20. Hybrid and Electric Advanced Vehicle Systems Simulation

    Science.gov (United States)

    Beach, R. F.; Hammond, R. A.; Mcgehee, R. K.

    1985-01-01

    Predefined components connected to represent wide variety of propulsion systems. Hybrid and Electric Advanced Vehicle System (HEAVY) computer program is flexible tool for evaluating performance and cost of electric and hybrid vehicle propulsion systems. Allows designer to quickly, conveniently, and economically predict performance of proposed drive train.

  1. 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

  2. Improving the physical properties of starch using a new kind of water dispersible nano-hybrid reinforcement.

    Science.gov (United States)

    Morales, Noé J; Candal, Roberto; Famá, Lucía; Goyanes, Silvia; Rubiolo, Gerardo H

    2015-08-20

    Plasticized cassava starch matrix composites reinforced by a multi-wall carbon nanotube (MWCNT)-hercynite (FeAl2O4) nanomaterial were developed. The hybrid nanomaterial consists of FeAl2O4 nanoparticles anchored strongly to the surface of the MWCNT. This nano-hybrid filler shows an irregular geometry, which provides a strong mechanical interlocking with the matrix, and excellent stability in water, ensuring a good dispersion in the starch matrix. The composite containing 0.04wt.% of the nano-hybrid filler displays increments of 370% in the Young's modulus, 138% in tensile strength and 350% in tensile toughness and a 70% decrease in water vapor permeability relative to the matrix material. All of these significant improvements are explained in terms of the nano-hybrid filler homogenous dispersion and its high affinity with both plasticizers, glycerol and water, which induces crystallization without deterioration of the tensile toughness.

  3. Symmetry reduction for stochastic hybrid systems

    NARCIS (Netherlands)

    Bujorianu, L.M.; Katoen, J.P.

    2009-01-01

    This paper is focused on adapting symmetry reduction, a technique that is highly successful in traditional model checking, to stochastic hybrid systems. We first show that performability analysis of stochastic hybrid systems can be reduced to a stochastic reachability analysis (SRA). Then, we genera

  4. Symmetry Reduction For Stochastic Hybrid Systems

    NARCIS (Netherlands)

    Bujorianu, L.M.; Katoen, J.P.

    2008-01-01

    This paper is focused on adapting symmetry reduction, a technique that is highly successful in traditional model checking, to stochastic hybrid systems. To that end, we first show that performability analysis of stochastic hybrid systems can be reduced to a stochastic reachability analysis (SRA). Th

  5. Hybrid logics with infinitary proof systems

    NARCIS (Netherlands)

    Kooi, Barteld; Renardel de Lavalette, Gerard; Verbrugge, Rineke

    2006-01-01

    We provide a strongly complete infinitary proof system for hybrid logic. This proof system can be extended with countably many sequents. Thus, although these logics may be non-compact, strong completeness proofs are provided for infinitary hybrid versions of non-compact logics like ancestral logic a

  6. Statistical Model Checking for Stochastic Hybrid Systems

    DEFF Research Database (Denmark)

    David, Alexandre; Du, Dehui; Larsen, Kim Guldstrand

    2012-01-01

    This paper presents novel extensions and applications of the UPPAAL-SMC model checker. The extensions allow for statistical model checking of stochastic hybrid systems. We show how our race-based stochastic semantics extends to networks of hybrid systems, and indicate the integration technique ap...

  7. Fault tolerant control design for hybrid systems

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hao; Jiang, Bin [Nanjing University of Aeronautics and Astronautics, Nanjing (China); Cocquempot, Vincent [Universite des Sciences et Technologies de Lille, Villeneuve d' Ascq (France)

    2010-07-01

    This book intends to provide the readers a good understanding on how to achieve Fault Tolerant Control goal of Hybrid Systems. The book can be used as a reference for the academic research on Fault Tolerant Control and Hybrid Systems or used in Ph.D. study of control theory and engineering. The knowledge background for this monograph would be some undergraduate and graduate courses on Fault Diagnosis and Fault Tolerant Control theory, linear system theory, nonlinear system theory, Hybrid Systems theory and Discrete Event System theory. (orig.)

  8. Sitotoksisitas resin akrilik hybrid setelah penambahan glass fiber dengan metode berbeda (Cytotoxicity of the hybrid acrylic resin after glass fiber reinforcement with difference method

    Directory of Open Access Journals (Sweden)

    Intan Nirwana

    2005-06-01

    Full Text Available Glass fiber reinforcement of the hybrid acrylic resin with difference method can enhance residual monomer content of the material; it can cause cytotoxic effect on fibroblast cells. The purpose of this study was to know the cytotoxicity of hybrid acrylic resins after glass fiber reinforcement with difference method on the cultured fibroblasts. The squared specimens of 10 mm in length, 10 mm in width and 1.5 mm in thickness were cured for 20 minutes at 100° C. The fibroblast cells were grown in Eagle's Minimum Essential Medium to be 2 × 105 cells/ml, then the cells were added to the samples in the plates and incubated at 37° C. After 48 hours, the cytotoxic effect was determined by direct cell number count using microscope and a hemocytometer. The statistical analyses using one way ANOVA and LSD test showed that there were significant difference in cell viability (p < 0.05 among the groups. The means percentage of cell viability were 90.00%, 99.,11%, 98.66%, it could be concluded that glass fiber reinforcement into hybrid acrylic resin with either first method or second method was not toxic.

  9. Reinforcement learning for adaptive dialogue systems

    CERN Document Server

    Rieser, Verena

    2011-01-01

    The past decade has seen a revolution in the field of spoken dialogue systems. As in other areas of Computer Science and Artificial Intelligence, data-driven methods are now being used to drive new methodologies for system development and evaluation. This book is a unique contribution to that ongoing change. A new methodology for developing spoken dialogue systems is described in detail. The journey starts and ends with human behaviour in interaction, and explores methods for learning from the data, for building simulation environments for training and testing systems, and for evaluating the r

  10. Shear Strength of Unreinforced Masonry Wall Retrofitted with Fiber Reinforced Polymer and Hybrid Sheet

    Directory of Open Access Journals (Sweden)

    Yun-Cheul Choi

    2015-01-01

    Full Text Available Unreinforced masonry (URM structures represent a significant portion of existing historical structures around the world. Recent earthquakes have shown the need for seismic retrofitting for URM structures. Various types of strengthening methods have been used for URM structures. In particular, a strengthening technique using externally bonded (EB fiber reinforced polymer (FRP composites has attracted engineers since EB FRP materials effectively enhance the shear strength of URM walls with negligible change to cross-sectional area and weight of the walls. Research has been extensively conducted to determine characteristics of URM walls strengthened with EB FRP materials. However, it is still difficult to determine an appropriate retrofitting level due to the complexity of mechanical behavior of strengthened URM walls. In this study, in-plane behavior under lateral loading was, therefore, investigated on a full-scale nonstrengthened URM wall and URM walls retrofitted with two different FRP materials: carbon (CFRP and hybrid (HFRP sheets. The test results indicated that both FRP composites were effective in increasing shear strength in comparison with the control specimen. However, better performance was obtained with HFRP compared to CFRP. In addition, an equation for estimating effective strain was proposed, and the theoretical results were in good agreement with the experimental ones.

  11. Effect of Short Fiber Reinforcement on Mechanical Properties of Hybrid Phenolic Composites

    Directory of Open Access Journals (Sweden)

    Sembian Manoharan

    2014-01-01

    Full Text Available Fiber plays an important role in determining the hardness, strength, and dynamic mechanical properties of composite material. In the present work, enhancement of viscoelastic behaviour of hybrid phenolic composites has been synergistically investigated. Five different phenolic composites, namely, C1, C2, C3, C4, and C5, were fabricated by varying the weight percentage of basalt and aramid fiber, namely, 25, 20, 15, 10, and 5% by compensating with barium sulphate (BaSO4 to keep the combined reinforcement concentration at 25 wt%. Hardness was measured to examine the resistance of composites to indentation. The hardness of phenolic composites increased from 72.2 to 85.2 with increase in basalt fiber loading. Composite C1 (25 wt% fiber is 1.2 times harder than composite C5. Compression test was conducted to find out compressive strength of phenolic composites and compressive strength increased with increase in fiber content. Dynamic mechanical analysis (DMA was carried out to assess the temperature dependence mechanical properties in terms of storage modulus (E′, loss modulus (E′′, and damping factor (tan δ. The results indicate great improvement of E′ values and decrease in damping behaviour of composite upon fiber addition. Further X-ray powder diffraction (XRD and energy-dispersive X-ray (EDX analysis were employed to characterize the friction composites.

  12. Structural considerations in friction welding of hybrid Al2O3-reinforced aluminum composites

    Institute of Scientific and Technical Information of China (English)

    In-Duck PARK; Choon-Tae LEE; Hyur-Soo KIM; Woo-Jin CHOI; Myung-Chang KANG

    2011-01-01

    Comparative studies on the relationship between the welding parameters and joining efficiency in the friction welding of hybrid Al2O3-reinforced aluminum composites were conducted. Metal matrix composites (MMCs) with 37% (volume fraction)aluminum particle were joined by friction welding. The results show that the effects of the rotation speed on the reduction rate of particle size are greater than those of the upset pressure, and the area of the MMC weld zone decreases as the joining efficiency increases, while it is considered that the joining efficiency does not increase as the reduction rate of particle size decreases. During the macro-examination of the bonding interface. a gray discolored region was observed on the bonding interface, and the center of the region was dark gray. After the micro-examination of the bonding interface, base metal made some second particulate formed by condensed alumina particulate but discoloration part distributed minute alumina particulate without second particulate. Consequently,it was also observed that rotational speed of 3 000 r/min and upset pressure of 63.6 MPa showed a very good joint.

  13. Impact Strength and Flexural Properties Enhancement of Methacrylate Silane Treated Oil Palm Mesocarp Fiber Reinforced Biodegradable Hybrid Composites

    OpenAIRE

    Chern Chiet Eng; Nor Azowa Ibrahim; Norhazlin Zainuddin; Hidayah Ariffin; Wan Md Zin Wan Yunus

    2014-01-01

    Natural fiber as reinforcement filler in polymer composites is an attractive approach due to being fully biodegradable and cheap. However, incompatibility between hydrophilic natural fiber and hydrophobic polymer matrix restricts the application. The current studies focus on the effects of incorporation of silane treated OPMF into polylactic acid (PLA)/polycaprolactone (PCL)/nanoclay/OPMF hybrid composites. The composites were prepared by melt blending technique and characterize the composite...

  14. Effect of surface treatment on mechanical properties of glass fiber/stainless steel wire mesh reinforced epoxy hybrid composites

    Energy Technology Data Exchange (ETDEWEB)

    N, Karunagaran [S.K.P Engineering College, Tiruvannamalai (India); A, Rajadurai [Anna University, Chennai (India)

    2016-06-15

    This paper investigates the effect of surface treatment for glass fiber, stainless steel wire mesh on tensile, flexural, inter-laminar shear and impact properties of glass fiber/stainless steel wire mesh reinforced epoxy hybrid composites. The glass fiber fabric is surface treated either by 1 N solution of sulfuric acid or 1 N solution of sodium hydroxide. The stainless steel wire mesh is also surface treated by either electro dissolution or sand blasting. The hybrid composites are fabricated using epoxy resin reinforced with glass fiber and fine stainless steel wire mesh by hand lay-up technique at room temperature. The hybrid composite consisting of acid treated glass fiber and sand blasted stainless steel wire mesh exhibits a good combination of tensile, flexural, inter-laminar shear and impact behavior in comparison with the composites made without any surface treatment. The fine morphological modifications made on the surface of the glass fiber and stainless steel wire mesh enhances the bonding between the resin and reinforcement which inturn improved the tensile, flexural, inter-laminar shear and impact properties.

  15. Hybrid dynamical systems observation and control

    CERN Document Server

    Defoort, Michael

    2015-01-01

    This book is a collection of contributions defining the state of current knowledge and new trends in hybrid systemssystems involving both continuous dynamics and discrete events – as described by the work of several well-known groups of researchers. Hybrid Dynamical Systems presents theoretical advances in such areas as diagnosability, observability and stabilization for various classes of system. Continuous and discrete state estimation and self-triggering control of nonlinear systems are advanced. The text employs various methods, among them, high-order sliding modes, Takagi–Sugeno representation and sampled-data switching to achieve its ends. The many applications of hybrid systems from power converters to computer science are not forgotten; studies of flexible-joint robotic arms and – as representative biological systems – the behaviour of the human heart and vasculature, demonstrate the wide-ranging practical significance of control in hybrid systems. The cross-disciplinary origins of study ...

  16. Mechanical Properties of Natural Jute Fabric/Jute Mat Fiber Reinforced Polymer Matrix Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Elsayed A. Elbadry

    2012-01-01

    Full Text Available Recycled needle punched jute fiber mats as a first natural fiber reinforcement system and these jute mats used as a core needle punched with recycled jute fabric cloths as skin layers as a second natural fiber reinforcement system were used for unsaturated polyester matrix composites via modifying the hand lay-up technique with resin preimpregnation into the jute fiber in vacuum. The effect of skin jute fabric on the tensile and bending properties of jute mat composites was investigated for different fiber weight contents. Moreover, the notch sensitivity of these composites was also compared by using the characteristic distance do calculated by Finite Element Method (FEM. The results showed that the tensile and flexural properties of jute mat composites increased by increasing the fiber weight content and by adding the jute fabric as skin layers. On the other hand, by adding the skins, the characteristic distance decreased and, therefore, the notch sensitivity of the composites increased. The fracture behavior investigated by SEM showed that extensive fiber pull-out mechanism was revealed at the tension side of jute mat composites under the bending load and by adding the jute cloth, the failure mode of jute mat was changed to fiber bridge mechanism.

  17. Advanced propulsion system concept for hybrid vehicles

    Science.gov (United States)

    Bhate, S.; Chen, H.; Dochat, G.

    1980-01-01

    A series hybrid system, utilizing a free piston Stirling engine with a linear alternator, and a parallel hybrid system, incorporating a kinematic Stirling engine, are analyzed for various specified reference missions/vehicles ranging from a small two passenger commuter vehicle to a van. Parametric studies for each configuration, detail tradeoff studies to determine engine, battery and system definition, short term energy storage evaluation, and detail life cycle cost studies were performed. Results indicate that the selection of a parallel Stirling engine/electric, hybrid propulsion system can significantly reduce petroleum consumption by 70 percent over present conventional vehicles.

  18. Novel hybrid columns made of ultra-high performance concrete and fiber reinforced polymers

    Science.gov (United States)

    Zohrevand, Pedram

    The application of advanced materials in infrastructure has grown rapidly in recent years mainly because of their potential to ease the construction, extend the service life, and improve the performance of structures. Ultra-high performance concrete (UHPC) is one such material considered as a novel alternative to conventional concrete. The material microstructure in UHPC is optimized to significantly improve its material properties including compressive and tensile strength, modulus of elasticity, durability, and damage tolerance. Fiber-reinforced polymer (FRP) composite is another novel construction material with excellent properties such as high strength-to-weight and stiffness-to-weight ratios and good corrosion resistance. Considering the exceptional properties of UHPC and FRP, many advantages can result from the combined application of these two advanced materials, which is the subject of this research. The confinement behavior of UHPC was studied for the first time in this research. The stress-strain behavior of a series of UHPC-filled fiber-reinforced polymer (FRP) tubes with different fiber types and thicknesses were tested under uniaxial compression. The FRP confinement was shown to significantly enhance both the ultimate strength and strain of UHPC. It was also shown that existing confinement models are incapable of predicting the behavior of FRP-confined UHPC. Therefore, new stress-strain models for FRP-confined UHPC were developed through an analytical study. In the other part of this research, a novel steel-free UHPC-filled FRP tube (UHPCFFT) column system was developed and its cyclic behavior was studied. The proposed steel-free UHPCFFT column showed much higher strength and stiffness, with a reasonable ductility, as compared to its conventional reinforced concrete (RC) counterpart. Using the results of the first phase of column tests, a second series of UHPCFFT columns were made and studied under pseudo-static loading to study the effect of column

  19. Hybrid robot climbing system design

    Science.gov (United States)

    Purna Irawan, Agustinus; Halim, Agus; Kurniawan, Hengky

    2017-09-01

    This research aims to develop a climbing hybrid robot, especially to design the structure of robot that quite strong and how to build an optimal mechanism for transmitting the motor’s rotation and torque to generate movement up the pole. In this research we use analytical methods using analysis software, simulation, a prototype, and robot trial. The result showed that robot could climb a pole by with maximum velocity 0.33m/s with a 20 kg load. Based on a weight diversity trial between 10 kg and 20 kg we obtained climb up load factor with value 0.970 ± 0.0223 and climb down load factor with value 0.910 ± 0.0163. Displacement of the frame structure was 7.58 mm. To minimize this displacement, the gate system was used so as to optimize the gripper while gripping the pole. The von Misses stress in the roller was 48.49 MPa, with 0.12 mm of displacement. This result could be a reference for robot development in further research.

  20. Hydrofluoric–nitric–sulphuric-acid surface treatment of tungsten for carbon fibre-reinforced composite hybrids in space applications

    Energy Technology Data Exchange (ETDEWEB)

    Kanerva, M., E-mail: Mikko.Kanerva@aalto.fi [Aalto University, School of Engineering, Department of Applied Mechanics, P.O.B. 14300, FI-00076 Aalto (Finland); Johansson, L.-S.; Campbell, J.M. [Aalto University, School of Chemical Technology, Department of Forest Products Technology, P.O.B. 16300, FI-00076 Aalto (Finland); Revitzer, H. [Aalto University, School of Chemical Technology, Department of Chemistry, P.O.B. 16300, FI-00076 Aalto (Finland); Sarlin, E. [Tampere University of Technology, Department of Materials Science, P.O.B. 589, FI-33101 Tampere (Finland); Brander, T.; Saarela, O. [Aalto University, School of Engineering, Department of Applied Mechanics, P.O.B. 14300, FI-00076 Aalto (Finland)

    2015-02-15

    Highlights: • XPS and AFM analysis of the effect of hydrofluoric–nitric–sulphuric-acid on tungsten. • Dreiling's model established 54.4% thinning of WO{sub 3} due to 67 s treatment. • Strain energy release rate increased ≈8.4 J/m{sup 2} at the interface. • Failure loci analysis expressed the oxide and carbon fibre surfaces as weak points. - Abstract: Hybrid material systems, such as combinations of tungsten foils and carbon fibre-reinforced plastic (CFRP), are replacing metal alloy concepts in spacecraft enclosures. However, a good adhesion between the tungsten oxide scale and the epoxy resin used is required. Here, the effects of a hydrofluoric–nitric–sulphuric-acid (HFNS) treatment on tungsten oxides and subsequent adhesion to CFRP are analysed using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and fracture testing. The work shows that HFNS treatment results in decreased oxygen content, over 50% thinner tungsten trioxide (WO{sub 3}) layer and increased nano-roughness on thin tungsten foils. Fracture testing established a 39% increase in the average critical strain for tungsten–CFRP specimens after HFNS treatment was carried out on tungsten. The effect of the oxide scale modification regarding the critical strain energy release rate was ΔG{sub c}≈ 8.4 J/m{sup 2}.

  1. Preparation and thermal shock resistance of high emissivity molybdenum disilicide- aluminoborosilicate glass hybrid coating on fiber reinforced aerogel composite

    Science.gov (United States)

    Shao, Gaofeng; Lu, Yucao; Wu, Xiaodong; Wu, Jun; Cui, Sheng; Jiao, Jian; Shen, Xiaodong

    2017-09-01

    To develop a flexible reusable surface insulation for thermal protection system, MoSi2-aluminoborosilicate glass hybrid coatings have been prepared on Al2O3 fiber reinforced Al2O3-SiO2 aerogel composite by slurry dipping and rapid sintering method. The effect of MoSi2 content on radiative property and thermal shock behavior was investigated. The total emissivity values of all the coatings exceeded 0.85 in the wavelength of 0.8-2.5 μm. The M10 and M50 coatings were up to 0.9, which was due to the highest amorphous glass content of the M10 coating and the largest surface roughness of the M50 coating. The M30 coated composite showed the best thermal shock resistance with only 0.023% weight loss after 20 thermal shock cycles between 1473 K and room temperature, which was attributed to the similar thermal expansion coefficients between the coating and the substrate and the appropriate viscosity of aluminoborosilicate glass at 1473 K. The cracks resulted from CTE mismatch stress with different sizes formed and grew on the surface of M10, M40 and M50 coated samples, leading to the failure of the composites.

  2. Bond Strength between Hybrid Fiber-Reinforced Lightweight Aggregate Concrete Substrate and Self-Compacting Concrete as Topping Layer

    Directory of Open Access Journals (Sweden)

    Slamet Widodo

    2017-01-01

    Full Text Available Structural performance evaluation of composite concrete slabs that were constructed using partially precast concreting system which utilized Hybrid Fiber-Reinforced Lightweight Aggregate Concrete (HyFRLWAC as stay in-place formwork and self-compacting concrete (SCC as topping layer was conducted in this research. This paper focused on determining the appropriate strength limit criteria of interface between two different concrete layers. The tensile strength was tested using pull-off test, while concrete cohesion was investigated based on modified bisurface shear test, and dual L-shaped shear test was used to determine the effect of normal force on the shear strength of concrete interface. Sample variants were designed based on the substrate surface conditions, compressive strength of the topping layer, and magnitude of perpendicular normal force acting on interface area. The substrate surfaces were prepared in as-placed and grooved conditions for tensile test, cohesion, and shear strength test. Test results indicate that tensile strength, cohesion, and shear strength of the concrete interface are affected by surface condition of the substrate, compressive strength of the topping layer, and the normal force acting perpendicularly on the concrete interface area. Proposed formulation for bond strength prediction between HyFRLWAC as substrate and SCC as topping layer is also presented in this paper.

  3. Safety Verification for Probabilistic Hybrid Systems

    DEFF Research Database (Denmark)

    Zhang, Lijun; She, Zhikun; Ratschan, Stefan;

    2010-01-01

    The interplay of random phenomena and continuous real-time control deserves increased attention for instance in wireless sensing and control applications. Safety verification for such systems thus needs to consider probabilistic variations of systems with hybrid dynamics. In safety verification...... hybrid systems and develop a general abstraction technique for verifying probabilistic safety problems. This gives rise to the first mechanisable technique that can, in practice, formally verify safety properties of non-trivial continuous-time stochastic hybrid systems-without resorting to point...... of classical hybrid systems we are interested in whether a certain set of unsafe system states can be reached from a set of initial states. In the probabilistic setting, we may ask instead whether the probability of reaching unsafe states is below some given threshold. In this paper, we consider probabilistic...

  4. Safety Verification for Probabilistic Hybrid Systems

    DEFF Research Database (Denmark)

    Zhang, Lijun; She, Zhikun; Ratschan, Stefan;

    2012-01-01

    The interplay of random phenomena and continuous dynamics deserves increased attention, especially in the context of wireless sensing and control applications. Safety verification for such systems thus needs to consider probabilistic variants of systems with hybrid dynamics. In safety verification...... hybrid systems and develop a general abstraction technique for verifying probabilistic safety problems. This gives rise to the first mechanisable technique that can, in practice, formally verify safety properties of non-trivial continuous-time stochastic hybrid systems. Moreover, being based...... of classical hybrid systems, we are interested in whether a certain set of unsafe system states can be reached from a set of initial states. In the probabilistic setting, we may ask instead whether the probability of reaching unsafe states is below some given threshold. In this paper, we consider probabilistic...

  5. Statistical Model Checking for Stochastic Hybrid Systems

    DEFF Research Database (Denmark)

    David, Alexandre; Du, Dehui; Larsen, Kim Guldstrand

    2012-01-01

    This paper presents novel extensions and applications of the UPPAAL-SMC model checker. The extensions allow for statistical model checking of stochastic hybrid systems. We show how our race-based stochastic semantics extends to networks of hybrid systems, and indicate the integration technique...... applied for implementing this semantics in the UPPAAL-SMC simulation engine. We report on two applications of the resulting tool-set coming from systems biology and energy aware buildings....

  6. Comparative analysis of the mechanical and thermal properties of polyester hybrid composites reinforced by jute and glass fiber.

    Directory of Open Access Journals (Sweden)

    Braga, R. A

    2015-05-01

    Full Text Available This work describes the study to investigate and compare the mechanical and thermal properties of raw jute and glass fiber reinforced polyester hybrid composites. To improve the mechanical properties, jute fiber was hybridized with glass fiber. Polyester resin, jute and glass fibers were laminated in three weight ratios(77/23/0, 68/25/7 and 56/21/23 respectively to form composites. The tensile, flexural, impact, density, thermal and water absorption tests were carried out using hybrid composite samples. This study shows that the addition of jute fiber and glass fiber in polyester, increase the density, the impact energy, the tensile strength and the flexural strength, but decrease the loss mass in function of temperature and the water absorption. Morphological analysis was carried out to observe fracture behavior and fiber pull-out of the samples using scanning electron microscope.

  7. Analysis of the mechanical and thermal properties of jute and glass fiber as reinforcement epoxy hybrid composites.

    Science.gov (United States)

    Braga, R A; Magalhaes, P A A

    2015-11-01

    This work describes the study to investigate and compare the mechanical and thermal properties of raw jute and glass fiber reinforced epoxy hybrid composites. To improve the mechanical properties, jute fiber was hybridized with glass fiber. Epoxy resin, jute and glass fibers were laminated in three weight ratios (69/31/0, 68/25/7 and 64/18/19) respectively to form composites. The tensile, flexural, impact, density, thermal and water absorption tests were carried out using hybrid composite samples. This study shows that the addition of jute fiber and glass fiber in epoxy, increases the density, the impact energy, the tensile strength and the flexural strength, but decreases the loss mass in function of temperature and the water absorption. Morphological analysis was carried out to observe fracture behavior and fiber pull-out of the samples using scanning electron microscope. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Sonication assisted preparation of graphene oxide/graphitic-C₃N₄ nanosheet hybrid with reinforced photocurrent for photocatalyst applications.

    Science.gov (United States)

    Dai, Kai; Lu, Luhua; Liu, Qi; Zhu, Guangping; Wei, Xiaoqin; Bai, Jin; Xuan, Lingling; Wang, Heng

    2014-05-01

    Graphitic C3N4 (g-C3N4), as an advanced metal free photocatalyst, is known to be poorly exfoliated and dispersed in water from its powder form which has a layered structure, the intrinsic plane structure is not destroyed, and this has largely limited its application. In this work, we report our progress on successful sonication exfoliation of g-C3N4 nanosheets in graphene oxide (GO) aqueous solution. By making use of the substrate character of GO, g-C3N4 nanosheets of unvaried intrinsic structure were exfoliated and anchored on the GO surface, resulting in a GO/g-C3N4 hybrid. Moreover, the photocurrent of the hybrid was largely reinforced at the optimal weight fraction of GO. As a result, the corresponding photocatalytic performance of the hybrid with optimized photocurrent character was largely improved.

  9. Impact strength and flexural properties enhancement of methacrylate silane treated oil palm mesocarp fiber reinforced biodegradable hybrid composites.

    Science.gov (United States)

    Eng, Chern Chiet; Ibrahim, Nor Azowa; Zainuddin, Norhazlin; Ariffin, Hidayah; Yunus, Wan Md Zin Wan

    2014-01-01

    Natural fiber as reinforcement filler in polymer composites is an attractive approach due to being fully biodegradable and cheap. However, incompatibility between hydrophilic natural fiber and hydrophobic polymer matrix restricts the application. The current studies focus on the effects of incorporation of silane treated OPMF into polylactic acid (PLA)/polycaprolactone (PCL)/nanoclay/OPMF hybrid composites. The composites were prepared by melt blending technique and characterize the composites with Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). FTIR spectra indicated that peak shifting occurs when silane treated OPMF was incorporated into hybrid composites. Based on mechanical properties results, incorporation of silane treated OPMF enhances the mechanical properties of unmodified OPMF hybrid composites with the enhancement of flexural and impact strength being 17.60% and 48.43%, respectively, at 10% fiber loading. TGA thermogram shows that incorporation of silane treated OPMF did not show increment in thermal properties of hybrid composites. SEM micrographs revealed that silane treated OPMF hybrid composites show good fiber/matrix adhesion as fiber is still embedded in the matrix and no cavity is present on the surface. Water absorption test shows that addition of less hydrophilic silane treated OPMF successfully reduces the water uptake of hybrid composites.

  10. Impact Strength and Flexural Properties Enhancement of Methacrylate Silane Treated Oil Palm Mesocarp Fiber Reinforced Biodegradable Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Chern Chiet Eng

    2014-01-01

    Full Text Available Natural fiber as reinforcement filler in polymer composites is an attractive approach due to being fully biodegradable and cheap. However, incompatibility between hydrophilic natural fiber and hydrophobic polymer matrix restricts the application. The current studies focus on the effects of incorporation of silane treated OPMF into polylactic acid (PLA/polycaprolactone (PCL/nanoclay/OPMF hybrid composites. The composites were prepared by melt blending technique and characterize the composites with Fourier transform infrared spectroscopy (FTIR, thermogravimetric analysis (TGA, and scanning electron microscopy (SEM. FTIR spectra indicated that peak shifting occurs when silane treated OPMF was incorporated into hybrid composites. Based on mechanical properties results, incorporation of silane treated OPMF enhances the mechanical properties of unmodified OPMF hybrid composites with the enhancement of flexural and impact strength being 17.60% and 48.43%, respectively, at 10% fiber loading. TGA thermogram shows that incorporation of silane treated OPMF did not show increment in thermal properties of hybrid composites. SEM micrographs revealed that silane treated OPMF hybrid composites show good fiber/matrix adhesion as fiber is still embedded in the matrix and no cavity is present on the surface. Water absorption test shows that addition of less hydrophilic silane treated OPMF successfully reduces the water uptake of hybrid composites.

  11. In situ corrosion monitoring of PC structures with distributed hybrid carbon fiber reinforced polymer sensors

    Science.gov (United States)

    Yang, C. Q.; Wu, Z. S.

    2007-08-01

    Firstly, the fabrication and sensing properties of hybrid carbon fiber reinforced polymer (HCFRP) composite sensors are addressed. In order to provide a distributed sensing manner, the HCFRP sensors were divided into multi-zones with electrodes, and each zone was regarded as a separate sensor. Secondly, their application is studied to monitor the steel corrosion of prestressed concrete (PC) beams. The HCFRP sensors with different gauge lengths were mounted on a PC tendon, steel bar and embedded in tensile and compressive sides of the PC beam. The experiment was carried out under an electric accelerated corrosion and a constant load of about 54 kN. The results reveal that the corrosion of the PC tendon can be monitored through measuring the electrical resistance (ER) change of the HCFRP sensors. For the sensors embedded in tensile side of the PC beam, their ER increases as the corrosion progresses, whereas for the sensors embedded in compressive side, their ER decreases with corrosion time. Moreover, the strains due to the corrosion can be obtained based on the ER change and calibration curves of HCFRP sensors. The strains measured with traditional strain gauges agree with the strains calculated from the ER changes of HCFRP sensors. The electrical behavior of the zones where the corrosion was performed is much different from those of the other zones. In these zones, either there exist jumps in ER, or the ER increases with a much larger rate than those of the other zones. Distributed corrosion monitoring for PC structures is thus demonstrated with the application of HCFRP sensors through a proper installation of multi-electrodes.

  12. Structural behavior of hybrid GFRP and steel reinforced FRC prestressed beams

    OpenAIRE

    Mazaheripour, Hadi

    2016-01-01

    The present thesis intended to contribute for the development of a new generation of high durable and sustainable reinforced concrete (RC) beam structures submitted to flexural loading, by combining the benefits that Glass Fiber Reinforced Polymers (GFRP) and steel bars can provide: the former due to their corrosion immunity, and the latter derived from their high ductility. Furthermore, High Performance Fiber Reinforced Concrete (HPFRC) was developed to improve the ductility o...

  13. Recent Advances on Hybrid Intelligent Systems

    CERN Document Server

    Melin, Patricia; Kacprzyk, Janusz

    2013-01-01

    This book presents recent advances on hybrid intelligent systems using soft computing techniques for intelligent control and robotics, pattern recognition, time series prediction and optimization of complex problems. Soft Computing (SC) consists of several intelligent computing paradigms, including fuzzy logic, neural networks, and bio-inspired optimization algorithms, which can be used to produce powerful hybrid intelligent systems. The book is organized in five main parts, which contain groups of papers around a similar subject. The first part consists of papers with the main theme of hybrid intelligent systems for control and robotics, which are basically state of the art papers that propose new models and concepts, which can be the basis for achieving intelligent control and mobile robotics. The second part contains papers with the main theme of hybrid intelligent systems for pattern recognition and time series prediction, which are basically papers using nature-inspired techniques, like evolutionary algo...

  14. Reinforcement and Systemic Machine Learning for Decision Making

    CERN Document Server

    Kulkarni, Parag

    2012-01-01

    Reinforcement and Systemic Machine Learning for Decision Making There are always difficulties in making machines that learn from experience. Complete information is not always available-or it becomes available in bits and pieces over a period of time. With respect to systemic learning, there is a need to understand the impact of decisions and actions on a system over that period of time. This book takes a holistic approach to addressing that need and presents a new paradigm-creating new learning applications and, ultimately, more intelligent machines. The first book of its kind in this new an

  15. Analysis of Hybrid Hydrogen Systems: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Dean, J.; Braun, R.; Munoz, D.; Penev, M.; Kinchin, C.

    2010-01-01

    Report on biomass pathways for hydrogen production and how they can be hybridized to support renewable electricity generation. Two hybrid systems were studied in detail for process feasibility and economic performance. The best-performing system was estimated to produce hydrogen at costs ($1.67/kg) within Department of Energy targets ($2.10/kg) for central biomass-derived hydrogen production while also providing value-added energy services to the electric grid.

  16. Electrical Resistivity, Tribological Behaviour of Multiwalled Carbon Nanotubes and Nanoboron Carbide Particles Reinforced Copper Hybrid Composites for Pantograph Application

    Directory of Open Access Journals (Sweden)

    N. Selvakumar

    2016-01-01

    Full Text Available This work focuses on the influence and contribution of multiwalled carbon-nanotube (MWCNT–boron carbide (B4C to the mechanical and tribological properties of copper matrix composites. Different weight fractions of nano- B4C-containing fixed-weight fractions of MWCNT-reinforced copper composites were prepared using the entrenched cold-press sintering method of powder metallurgy. The wear losses of sintered Cu–MWCNT–B4C composites were investigated by conducting sliding tests in a pin-on-disc apparatus. The addition of reinforcements showed enhancements in the hardness and wear properties of the composites due to the uniform dispersion of the secondary reinforcement in the copper matrix and the self-lubricating effect of the MWCNTs. The effects of the nanoparticle distribution in the matrix, the worn surface morphology, and the elemental composition of the composites were characterized using high-resolution scanning electron microscopy and X-ray diffraction analysis. The electrical resistivity of the fabricated copper hybrid composite preforms was evaluated using a four-point probe tester. Our results highlight the use of experiential reinforcing limits of B4C on the wear and electrical and mechanical behaviour of copper composites.

  17. Mechanical Property Analysis on Sandwich Structured Hybrid Composite Made from Natural Fibre, Glass Fibre and Ceramic Fibre Wool Reinforced with Epoxy Resin

    Science.gov (United States)

    Bharat, K. R.; Abhishek, S.; Palanikumar, K.

    2017-06-01

    Natural fibre composites find wide range of applications and usage in the automobile and manufacturing industries. They find lack in desired properties, which are required for present applications. In current scenario, many developments in composite materials involve the synthesis of Hybrid composite materials to overcome some of the lacking properties. In this present investigation, two sandwich structured hybrid composite materials have been made by reinforcing Aloe Vera-Ceramic Fibre Wool-Glass fibre with Epoxy resin matrix and Sisal fibre-Ceramic Fibre Wool-Glass fibre with Epoxy resin matrix and its mechanical properties such as Tensile, Flexural and Impact are tested and analyzed. The test results from the two samples are compared and the results show that sisal fibre reinforced hybrid composite has better mechanical properties than aloe vera reinforced hybrid composite.

  18. Implementation of real-time energy management strategy based on reinforcement learning for hybrid electric vehicles and simulation validation.

    Science.gov (United States)

    Kong, Zehui; Zou, Yuan; Liu, Teng

    2017-01-01

    To further improve the fuel economy of series hybrid electric tracked vehicles, a reinforcement learning (RL)-based real-time energy management strategy is developed in this paper. In order to utilize the statistical characteristics of online driving schedule effectively, a recursive algorithm for the transition probability matrix (TPM) of power-request is derived. The reinforcement learning (RL) is applied to calculate and update the control policy at regular time, adapting to the varying driving conditions. A facing-forward powertrain model is built in detail, including the engine-generator model, battery model and vehicle dynamical model. The robustness and adaptability of real-time energy management strategy are validated through the comparison with the stationary control strategy based on initial transition probability matrix (TPM) generated from a long naturalistic driving cycle in the simulation. Results indicate that proposed method has better fuel economy than stationary one and is more effective in real-time control.

  19. Uncertainty Quantification in Hybrid Dynamical Systems

    CERN Document Server

    Sahai, Tuhin

    2011-01-01

    Uncertainty quantification (UQ) techniques are frequently used to ascertain output variability in systems with parametric uncertainty. Traditional algorithms for UQ are either system-agnostic and slow (such as Monte Carlo) or fast with stringent assumptions on smoothness (such as polynomial chaos and Quasi-Monte Carlo). In this work, we develop a fast UQ approach for hybrid dynamical systems by extending the polynomial chaos methodology to these systems. To capture discontinuities, we use a wavelet-based Wiener-Haar expansion. We develop a boundary layer approach to propagate uncertainty through separable reset conditions. We also introduce a transport theory based approach for propagating uncertainty through hybrid dynamical systems. Here the expansion yields a set of hyperbolic equations that are solved by integrating along characteristics. The solution of the partial differential equation along the characteristics allows one to quantify uncertainty in hybrid or switching dynamical systems. The above method...

  20. Uncertainty quantification in hybrid dynamical systems

    Science.gov (United States)

    Sahai, Tuhin; Pasini, José Miguel

    2013-03-01

    Uncertainty quantification (UQ) techniques are frequently used to ascertain output variability in systems with parametric uncertainty. Traditional algorithms for UQ are either system-agnostic and slow (such as Monte Carlo) or fast with stringent assumptions on smoothness (such as polynomial chaos and Quasi-Monte Carlo). In this work, we develop a fast UQ approach for hybrid dynamical systems by extending the polynomial chaos methodology to these systems. To capture discontinuities, we use a wavelet-based Wiener-Haar expansion. We develop a boundary layer approach to propagate uncertainty through separable reset conditions. We also introduce a transport theory based approach for propagating uncertainty through hybrid dynamical systems. Here the expansion yields a set of hyperbolic equations that are solved by integrating along characteristics. The solution of the partial differential equation along the characteristics allows one to quantify uncertainty in hybrid or switching dynamical systems. The above methods are demonstrated on example problems.

  1. Supermarket Refrigeration System - Benchmark for Hybrid System Control

    DEFF Research Database (Denmark)

    Sloth, Lars Finn; Izadi-Zamanabadi, Roozbeh; Wisniewski, Rafal

    2007-01-01

    This paper presents a supermarket refrigeration system as a benchmark for development of new ideas and a comparison of methods for hybrid systems' modeling and control. The benchmark features switch dynamics and discrete valued input making it a hybrid system, furthermore the outputs are subjected...

  2. Mechanical performance of hybrid polyester composites reinforced Cloisite 30B and kenaf fibre

    Science.gov (United States)

    Bonnia, N. N.; Surip, S. N.; Ratim, S.; Mahat, M. M.

    2012-06-01

    Hybridization of rubber toughened polyester-kenaf nanocomposite was prepared by adding various percentage of kenaf fiber with 4% Cloisite 30B in unsaturated polyester resin. Composite were prepared by adding filler to modified polyester resin subsequently cross-linked using methyl ethyl ketone peroxide and the accelerator cobalt octanoate 1%. Three per hundred rubbers (phr) of liquid natural rubber (LNR) were added in producing this composite. This composite expected to be applied in the interior of passenger cars and truck cabins. This is a quality local product from a combination of good properties polyester and high performance natural fiber, kenaf that is suitable for many applications such as in automotive sector and construction sector. The mechanical and thermal properties of composite were characterized using Durometer Shore-D hardness test, Izod impact test, Scanning electron microscopy, thermogravimetry (TGA) and differential scanning calorimetry (DSC). Result shows that addition of LNR give good properties on impact, flexural and hardness compare to without LNR composite. DSC curve shows that all composition of composites is fully cured and good in thermal properties. Addition of higher percentage of kenaf will lead the composite to elastic behavior and decrease the toughened properties of the composite. Hybrid system composite showed the flexural properties within the flexural properties of kenaf - polyester and Cloisite 30B.

  3. Mechanical and tribological studies of polymer hybrid nanocomposites with nano reinforcements

    Indian Academy of Sciences (India)

    D Lingaraju; K Ramji; M Pramila Devi; U Rajya Lakshmi

    2011-07-01

    Developments of nanoparticle reinforced plastics are of growing interest towards the emergence of new materials which enhance optimal utilization of natural resources and particularly of renewable resources. The effects of nanoparticles as fillers in glass–epoxy composite systems on the mechanical and tribological properties have been discussed in this article. The mechanical properties such as tensile strength, impact strength, flexural strength, and hardness have been studied in accordance with ASTM standards. The composites employed in the study have been fabricated using hand lay-up technique. By varying notch radius impact strength is studied. The clay and silica used in the present system were treated with 3-aminopropyltriethoxysilane. The effect of variants in sliding speed, time and applied load on the wear behavior of polymer nanocomposites is studied by measuring the weight changes and observing the surface features using scanning electron microscope. In the experiments with wear test pin having flat face in contact with hardening rotating steel disc, sliding speed, time and loads in the range of 640–1000 RPM, 300–900 s and 5–25 N respectively was used. It is observed that wear rate increases with increasing applied load, time and sliding speeds.

  4. Investigation of Mechanical and Electrical Properties of Hybrid Composites Reinforced with Carbon Nanotubes and Micrometer-Sized Silica Particles

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Yun; You, Byeong Il; Ahn, Ji Ho; Lee, Gyo Woo [Chonbuk Nat’l Univ., Junju (Korea, Republic of)

    2016-12-15

    In this study, to enhance the electrical insulation of composite specimens in addition to the improved mechanical properties, the epoxy composite were reinforced with carbon nanotubes and silica particles. Tensile strength, Young's modulus, dynamic mechanical behavior, and electrical resistivity of the specimens were measured with varied contents of the two fillers. The mechanical and electrical properties were discussed, and the experimental results related to the mechanical properties of the specimens were compared with those from several micromechanics models. The hybrid composites specimens with 0.6 wt% of carbon nanotubes and 50 wt% of silica particles showed improved mechanical properties, with increase in tensile strength and Young's modulus up to 11% and 35%, respectively, with respect to those of the baseline specimen. The electrical conductivity of the composite specimens with carbon nanotubes filler also improved. Further, the electrical insulation of the hybrid composites specimens with the two fillers improved in addition to the improvement in mechanical properties.

  5. Modular supervisory controller for hybrid power systems

    Energy Technology Data Exchange (ETDEWEB)

    Lemos Pereira, A. de

    2000-06-01

    The power supply of remote places has been commonly provided by thermal power plants, usually diesel generators. Although hybrid power systems may constitute the most economical solution in many applications their widespread application to the electrification schemes of remote areas still depends on improvements in the issues of design and operation control. The main limitations of the present hybrid power systems technology, which are identified in this work, are related to the control and supervision of the power system. Therefore this thesis focuses on the modularity of supervisory controllers in order to design cost-competitive and reliable hybrid power systems. The modular supervisory controller created in this project is considered an important part of a system design approach that aims to overcome the technical difficulties of the current engineering practice and contribute to open the market of hybrid power systems. The term modular refers to a set of design characteristics that allows the use of basically the same supervisory controller in different projects. The modularization and standardisation of the controller include several issues such as interfacing components, communication protocols, modelling, programming and control strategies. The modularity can reduce the highly specialised system engineering related to the integration of components, operation and control. It can also avoid the high costs for installation, service and maintenance. A modular algorithm for supervisory controllers has been developed (a Matlab program called SuperCon) using an object-oriented design and it has been tested through several simulations using different hybrid system configurations and different control strategies. This thesis presents a complete control system design process which can be used as the basis for the development and implementation of intelligent and autonomous supervisory controllers for hybrid power systems with modular characteristics. (au)

  6. A "Hybrid" Approach for Synthesizing Optimal Controllers of Hybrid Systems

    DEFF Research Database (Denmark)

    Zhao, Hengjun; Zhan, Naijun; Kapur, Deepak

    2012-01-01

    We propose an approach to reduce the optimal controller synthesis problem of hybrid systems to quantifier elimination; furthermore, we also show how to combine quantifier elimination with numerical computation in order to make it more scalable but at the same time, keep arising errors due...... to discretization manageable and within bounds. A major advantage of our approach is not only that it avoids errors due to numerical computation, but it also gives a better optimal controller. In order to illustrate our approach, we use the real industrial example of an oil pump provided by the German company HYDAC...

  7. Liquid fuel utilization in SOFC hybrid systems

    Energy Technology Data Exchange (ETDEWEB)

    Santin, Marco; Traverso, Alberto; Magistri, Loredana [TPG-DIMSET, University of Genoa, Via Montallegro 1, 16145 Genoa (Italy)

    2009-10-15

    The interest in solid oxide fuel cell systems comes from their capability of converting the chemical energy of traditional fuels into electricity, with high efficiency and low pollutant emissions. In this paper, a study of the design space of solid oxide fuel cell and gas turbine hybrids fed by methanol and kerosene is presented for stationary power generation in isolated areas (or transportation). A 500 kW class hybrid system was analysed using WTEMP original software developed by the Thermochemical Power Group of the University of Genoa. The choice of fuel-processing strategy and the influence of the main design parameters on the thermoeconomic characteristics of hybrid systems were investigated. The low capital and fuel cost of methanol systems make them the most attractive solutions among those investigated here. (author)

  8. A Generic Hybrid Encryption System (HES

    Directory of Open Access Journals (Sweden)

    Ijaz Ali Shoukat

    2013-03-01

    Full Text Available This study proposes a Generic Hybrid Encryption System (HES under mutual committee of symmetric and asymmetric cryptosystems. Asymmetric (public key Cryptosystems associates several performance issues like computational incompetence, memory wastages, energy consumptions and employment limitations on bulky data sets but they are quite secure and reliable in key exchange over insecure remote communication channels. Symmetric (private key cryptosystems are 100 times out performed, having no such issues but they cannot fulfill non-repudiation, false modifications in secret key, fake modifications in cipher text and origin authentication of both parties while exchanging information. These contradictory issues can be omitted by utilizing hybrid encryption mechanisms (symmetric+asymmetric to get optimal benefits of both schemes. Several hybrid mechanisms are available with different logics but our logic differs in infrastructural design, simplicity, computational efficiency and security as compared to prior hybrid encryption schemes. Some prior schemes are either diversified in performance aspects, customer satisfaction, memory utilization or energy consumptions and some are vulnerable against forgery and password guessing (session key recovery attacks. We have done some functional and design related changes in existing Public Key Infrastructure (PKI to achieve simplicity, optimal privacy and more customer satisfaction by providing Hybrid Encryption System (HES that is able to fulfill all set of standardized security constraints. No such PKI based generic hybrid encryption scheme persists as we have provided in order to manage all these kinds of discussed issues.

  9. Optimization and Static Stress Analysis of Hybrid Fiber Reinforced Composite Leaf Spring

    OpenAIRE

    Luay Muhammed Ali Ismaeel

    2015-01-01

    A monofiber reinforced composite leaf spring is proposed as an alternative to the typical steel one as it is characterized by high strength-to-weight ratio. Different reinforcing schemes are suggested to fabricate the leaf spring. The composite and the typical steel leaf springs are subjected to the same working conditions. A weight saving of about more than 60% can be achieved while maintaining the strength for the structures under consideration. The objective of the present study was to rep...

  10. Combined photovoltaic and thermal hybrid collector systems

    Energy Technology Data Exchange (ETDEWEB)

    Kern, E.C. Jr.; Russell, M.C.

    1978-01-01

    Solar energy collectors that produce both electric and thermal energy are an attractive alternative to individual thermal and photovoltaic collectors for certain applications and climates. Economic results from a system analysis indicate that hybrid collector systems are attractive in small buildings that have substantial heating loads. Passively cooled photovoltaic panels are best suited for structures located in regions where year-round air conditioning and small, low-grade, thermal energy demands predominate. Hybrid collectors are to be tested according to ASHRAE standards and a full-system experiment incorporating a photovoltaic array installed at the Solar Energy Research Facility of the University of Texas will be conducted by Lincoln Laboratory.

  11. Performance of Hybrid Reinforced Concrete Beam Column Joint: A Critical Review

    Directory of Open Access Journals (Sweden)

    Md Rashedul Kabir

    2016-04-01

    Full Text Available Large residual strain in reinforced concrete structures after a seismic event is a major concern for structural safety and serviceability. Alternative reinforcement materials like fiber-reinforced polymer (FRP have been widely used to mitigate corrosion problems associated with steel. Low modulus of elasticity and brittle behavior compared to steel has made the use of FRP unsuitable in seismic resistant strictures. A combination of steel-FRP reinforcement configuration can address the problem of corrosion. Therefore, introducing a material that shows strong post elastic behavior without any decay due to corrosion is in demand. Shape memory alloy (SMA, a novel material, is highly corrosion resistive and shows super elastic property. Coupling SMA with FRP or steel in the plastic hinge region allows the structure to undergo large deformations, but regains its original shape upon unloading. In this study, the performance characteristics of four previously tested beam-column joints reinforced with different configurations (steel, SMA/steel, glass fiber reinforced polymer (GFRP and SMA/FRP are compared to assess their capacity to endure extreme loading. Experimental results are scrutinized to compare the behavior of these specimens in terms of load-story drift and energy dissipation capacity. SMA/FRP and SMA/Steel couples have been found to be an acceptable approach to reduce residual deformation in beam-column joints with adequate energy dissipation capacity. However, SMA/FRP is superior to SMA/Steel concerning to the corrosion issue in steel.

  12. Control system for a hybrid powertrain system

    Energy Technology Data Exchange (ETDEWEB)

    Naqvi, Ali K.; Demirovic, Besim; Gupta, Pinaki; Kaminsky, Lawrence A.

    2014-09-09

    A vehicle includes a powertrain with an engine, first and second torque machines, and a hybrid transmission. A method for operating the vehicle includes operating the engine in an unfueled state, releasing an off-going clutch which when engaged effects operation of the hybrid transmission in a first continuously variable mode, and applying a friction braking torque to a wheel of the vehicle to compensate for an increase in an output torque of the hybrid transmission resulting from releasing the off-going clutch. Subsequent to releasing the off-going clutch, an oncoming clutch which when engaged effects operation of the hybrid transmission in a second continuously variable mode is synchronized. Subsequent to synchronization of the oncoming clutch, the oncoming clutch is engaged.

  13. Effect of winding layer and speed on kenaf/glass fiber hybrid reinforced acrylonitrile butadiene styrene (ABS) composites

    Science.gov (United States)

    Khoni, Norizzahthul Ainaa Abdul; Sharifah Shahnaz S., B.; Ghazali, Che Mohd Ruzaidi

    2016-07-01

    The usage of natural fiber is becoming significant in composite industries due to their good performance. Single and continuous natural fibers have relatively high mechanical properties; especially their young modulus can be as high as glass fibers. Filament winding is a method to produce technically aligned composites which have high fibers content. The properties of filament winding can be tailored to meet the end product requirements. This research studied the compression properties of kenaf/glass fibers hybrid reinforced composites. Kenaf/glass fibers hybrid composite samples were fabricated by filament winding technique and their properties were compared with the properties of neat kenaf fiber and glass fibers composites. The kenaf/glass fiber hybrid composites exhibited higher strength compared to the neat glass fibers composites. Composites of helical pattern, which produced at low winding speed showed better compression resistance than hoop pattern winding, which produced at high winding speed. As predicted, kenaf composite showed highest water absorption; followed by kenaf/glass fiber hybrid composites while neat glass fiber has lowest water absorption capability.

  14. Hybrid singular systems of differential equations

    Institute of Scientific and Technical Information of China (English)

    殷刚; 张纪峰

    2002-01-01

    This work develops hybrid models for large-scale singular differential system and analyzestheir asymptotic properties. To take into consideration the discrete shifts in regime across whichthe behavior of the corresponding dynamic systems is markedly different, our goals are to develophybrid systems in which continuous dynamics are intertwined with discrete events under random-jumpdisturbances and to reduce complexity of large-scale singular systems via singularly perturbed Markovchains. To reduce the complexity of large-scale hybrid singular systems, two-time scale is used in theformulation. Under general assumptions, limit behavior of the underlying system is examined. Usingweak convergence methods, it is shown that the systems can be approximated by limit systems inwhich the coefficients are averaged out with respect to the quasi-stationary distributions. Since thelimit systems have fewer states, the complexity is much reduced.

  15. Analysis and design of hybrid control systems

    Energy Technology Data Exchange (ETDEWEB)

    Malmborg, J.

    1998-05-01

    Different aspects of hybrid control systems are treated: analysis, simulation, design and implementation. A systematic methodology using extended Lyapunov theory for design of hybrid systems is developed. The methodology is based on conventional control designs in separate regions together with a switching strategy. Dynamics are not well defined if the control design methods lead to fast mode switching. The dynamics depend on the salient features of the implementation of the mode switches. A theorem for the stability of second order switching together with the resulting dynamics is derived. The dynamics on an intersection of two sliding sets are defined for two relays working on different time scales. The current simulation packages have problems modeling and simulating hybrid systems. It is shown how fast mode switches can be found before or during simulation. The necessary analysis work is a very small overhead for a modern simulation tool. To get some experience from practical problems with hybrid control the switching strategy is implemented in two different software environments. In one of them a time-optimal controller is added to an existing PID controller on a commercial control system. Successful experiments with this hybrid controller shows the practical use of the method 78 refs, 51 figs, 2 tabs

  16. Evolved Finite State Controller For Hybrid System

    DEFF Research Database (Denmark)

    Dupuis, Jean-Francois; Fan, Zhun; Goodman, Erik

    2009-01-01

    This paper presents an evolutionary methodology to automatically generate nite state automata (FSA) controllers to control hybrid systems. FSA controllers for a case study of two-tank system have been successfully obtained using the proposed evolutionary approach. Experimental results show...

  17. Thermo-mechanical characterization of siliconized E-glass fiber/hematite particles reinforced epoxy resin hybrid composite

    Science.gov (United States)

    V. R., Arun prakash; Rajadurai, A.

    2016-10-01

    In this present work hybrid polymer (epoxy) matrix composite has been strengthened with surface modified E-glass fiber and iron(III) oxide particles with varying size. The particle sizes of 200 nm and surface modification process has been done on both fiber and filler by an amino functional silane 3-Aminopropyltrimethoxysilane (APTMS). Crystalline and functional groups of siliconized iron(III) oxide particles were characterized by XRD and FTIR spectroscopy analysis. Fixed quantity of surface treated 15 vol% E-glass fiber was laid along with 0.5 and 1.0 vol% of iron(III) oxide particles into the matrix to fabricate hybrid composites. The composites were cured by an aliphatic hardener Triethylenetetramine (TETA). Effectiveness of surface modified particles and fibers addition into the resin matrix were revealed by mechanical testing like tensile testing, flexural testing, impact testing, inter laminar shear strength and hardness. Thermal behavior of composites was evaluated by TGA, DSC and thermal conductivity (Lee's disc). The scanning electron microscopy was employed to found shape and size of iron(III) oxide particles adhesion quality of fiber with epoxy matrix. Good dispersion of fillers in matrix was achieved with surface modifier APTMS. Tensile, flexural, impact and inter laminar shear strength of composites was improved by reinforcing surface modified fiber and filler. Thermal stability of epoxy resin was improved when surface modified fiber was reinforced along with hard hematite particles. Thermal conductivity of epoxy increased with increase of hematite content in epoxy matrix.

  18. Natural Fiber-Reinforced Hybrid Polymer Nanocomposites: Effect of Fiber Mixing and Nanoclay on Physical, Mechanical, and Biodegradable Properties

    Directory of Open Access Journals (Sweden)

    Md. Saiful Islam

    2015-01-01

    Full Text Available Combining two kinds of fibers is a potential way to improve the essential properties of natural fiber-reinforced hybrid polymer composites. Biocomposites produced from natural resources are experiencing an increase in interest due to their high demand in the market for manufacturing, in addition to environmental and sustainability issues. In this study, natural fiber-reinforced hybrid polymer nanocomposites were prepared from coir fiber, wood fiber, polypropylene, and montmorillonite nanoclay using a hot press technique. The effects of fiber mixing and montmorillonite on their physico-mechanical and biodegradable properties were subsequently investigated. Before being used, both the wood and the coir fibers were alkali-treated to reduce their hydrophilicity. The mechanical properties of the fabricated composites were measured using a universal tensile testing machine and found to be enhanced after fiber mixing and nanoclay incorporation. Fourier transform infrared spectra indicated that the characteristic peaks of the composites shifted after fiber mixing. A new peak around 470 cm-1 was observed in the case of the nanocomposites, which confirmed the interaction between the fiber, polymer, and montmorillonite (MMT. Scanning electron microscopic analysis revealed that MMT strongly improved the adhesion and compatibility between the fiber and polymer matrix. The combining of fibers improved the biodegradability and water absorption properties, while MMT addition had the reverse effect on the same properties of the composites.

  19. Tribological Wear Behaviour and Hardness Measurement of SiC, Al2O3 Reinforced Al. Matrix Hybrid Composite

    Science.gov (United States)

    Subramanian, Senthil Murugan; Vijayan, Jegan; Muthaiah, Velmurugan

    2017-01-01

    In the present study, Aluminium Matrix Hybrid Composite (AMHC) of 6061-T6 alloy reinforced with silicon carbide (SiC) particulate and further addition of aluminium oxide (Al2O3) particulate was fabricated by stir casting process. The wear resistance and frictional properties of that AMHC were studied by performing dry sliding wear test using a pin on disk wear tester. The experiments were conducted at a constant sliding velocity of 1.57 m/s and sliding distance of 1800 m under loading conditions of 10 and 20 N. Further tests were also carried out by keeping Al2O3 percentage (7%) constant and increasing the SiC percentage (10, 15, and 20%). The results show that the reinforcement of the metal matrix with SiC and Al2O3 reduces the wear rate range and also indicate that the wear of the test specimen increases with the increasing load and sliding distance. The coefficient of friction increases with load and increasing volume content of reinforcement. The worn surfaces were examined by scanning electron microscope to study the wear mechanism. By using wear mechanism analysis, the wear surfaces and wear properties of AMHC were determined.

  20. Numerical Hybrid Simulation Modeling Verification for a Curved 3-Pier Bridge (Investigation of Combined Actions on Reinforced Concrete Bridge Piers (CABER Project

    Directory of Open Access Journals (Sweden)

    Adel Abdelnaby

    2013-06-01

    Full Text Available Reinforced concrete bridge piers are subjected to complex loading conditions under earthquake ground motions. Bridge geometric irregularities and asymmetries result in combined actions imposed on the piers as a combination of displacements and rotations in all six degrees of freedom at the pier-deck juncture. Existing analytical tools have proven their inadequacy in representing the actual behavior of piers under these combined actions, particularly in their inelastic range. The objective of this investigation is to develop a fundamental understanding of the effects of these combined actions on the performance of RC piers and the resulting system response. This paper describes a part of the CABER project that verifies the numerical hybrid simulation of the curved bridge. In this part two models were introduced, a whole model and a sub-structured hybrid model. The whole model was established using the Zeus-NL analysis platform, which is capable of performing inelastic nonlinear response history analysis of the whole curved bridge. The hybrid model was divided into three modules which comprised the deck, left and right piers, and the middle pier of the bridge. The three modules were modeled by Zeus-NL as a static analysis module interface. The simulation coordinator (SimCor software was utilized to communicate between these modules using a Pseudo-Dynamic time integration scheme. Results obtained from both models were compared and conclusions were drawn.

  1. Transmission Reinforcements in the Central American Regional Power System

    Energy Technology Data Exchange (ETDEWEB)

    Elizondo, Marcelo A.; Vallem, Mallikarjuna R.; Samaan, Nader A.; Makarov, Yuri V.; Vyakaranam, Bharat; Nguyen, Tony B.; Munoz, Christian; Herrera, Ricardo; Midence, Diego; Shpitsberg, Anna

    2016-07-25

    The Central American regional interconnected power system (SER) connects the countries members of the Central American regional electricity market (MER): Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama. The SER was a result of a long term regional effort, and was initially conceived to transfer 300 MW between countries. However, the current transfer limits between countries range from 70 MW to 300 MW. Regional entities, like CRIE (Regional Commission of Electrical Interconnection), EOR (Central American Regional System Operator), and CDMER (Board of Directors of the Central American Market) are working on coordinating the national transmission expansion plans with regional transmission planning efforts. This paper presents experience in Central America region to recommend transmission reinforcements to achieve 300 MW transfer capacity between any pair of member countries of the Central American regional electricity market (MER). This paper also provides a methodology for technical analysis and for coordination among the regional and national entities. This methodology is unique for transmission systems of these characteristics.

  2. Systems Engineering of Electric and Hybrid Vehicles

    Science.gov (United States)

    Kurtz, D. W.; Levin, R. R.

    1986-01-01

    Technical paper notes systems engineering principles applied to development of electric and hybrid vehicles such that system performance requirements support overall program goal of reduced petroleum consumption. Paper discusses iterative design approach dictated by systems analyses. In addition to obvious peformance parameters of range, acceleration rate, and energy consumption, systems engineering also considers such major factors as cost, safety, reliability, comfort, necessary supporting infrastructure, and availability of materials.

  3. Systems Engineering of Electric and Hybrid Vehicles

    Science.gov (United States)

    Kurtz, D. W.; Levin, R. R.

    1986-01-01

    Technical paper notes systems engineering principles applied to development of electric and hybrid vehicles such that system performance requirements support overall program goal of reduced petroleum consumption. Paper discusses iterative design approach dictated by systems analyses. In addition to obvious peformance parameters of range, acceleration rate, and energy consumption, systems engineering also considers such major factors as cost, safety, reliability, comfort, necessary supporting infrastructure, and availability of materials.

  4. Hybrid piezoelectric energy harvesting transducer system

    Science.gov (United States)

    Xu, Tian-Bing (Inventor); Jiang, Xiaoning (Inventor); Su, Ji (Inventor); Rehrig, Paul W. (Inventor); Hackenberger, Wesley S. (Inventor)

    2008-01-01

    A hybrid piezoelectric energy harvesting transducer system includes: (a) first and second symmetric, pre-curved piezoelectric elements mounted separately on a frame so that their concave major surfaces are positioned opposite to each other; and (b) a linear piezoelectric element mounted separately on the frame and positioned between the pre-curved piezoelectric elements. The pre-curved piezoelectric elements and the linear piezoelectric element are spaced from one another and communicate with energy harvesting circuitry having contact points on the frame. The hybrid piezoelectric energy harvesting transducer system has a higher electromechanical energy conversion efficiency than any known piezoelectric transducer.

  5. Hybrid Battery Ultracapacitor System For Human Robotic Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this proposal is to develop a hybrid battery-ultra capacitor storage system that powers human-robotic systems in space missions. Space missions...

  6. Multiuser hybrid switched-selection diversity systems

    KAUST Repository

    Shaqfeh, Mohammad

    2011-09-01

    A new multiuser scheduling scheme is proposed and analyzed in this paper. The proposed system combines features of conventional full-feedback selection-based diversity systems and reduced-feedback switch-based diversity systems. The new hybrid system provides flexibility in trading-off the channel information feedback overhead with the prospected multiuser diversity gains. The users are clustered into groups, and the users\\' groups are ordered into a sequence. Per-group feedback thresholds are used and optimized to maximize the system overall achievable rate. The proposed hybrid system applies switched diversity criterion to choose one of the groups, and a selection criterion to decide the user to be scheduled from the chosen group. Numerical results demonstrate that the system capacity increases as the number of users per group increases, but at the cost of more required feedback messages. © 2011 IEEE.

  7. In-service performance and behavior characterization of the hybrid composite bridge system - a case study

    CERN Document Server

    Civitillo, John M; Gheitasi, Amir; Saliba, Mark; Kassner, Bernard L

    2014-01-01

    The Hybrid Composite Beam (HCB) system is an innovative structural technology that has been recently used in bridge construction within the U.S. transportation network. In this system, the superstructure consists of a conventional reinforced concrete deck supported by Hybrid Composite Beams. Each beam is comprised of a glassfiber reinforced polymer (FRP) box shell containing a tied parabolic concrete arch. Inclined stirrups provide shear integrity and enforce composite action between the HCBs and the concrete deck. This paper focuses on evaluating the in-service performance of a newly constructed HCB bridge superstructure located on Route 205 in Colonial Beach, Virginia. A live load test was conducted using tandem axle dump trucks under both quasi-static and dynamic conditions. Results obtained from the experimental investigation were used to determine three key behavior characteristics. Dynamic amplification and lateral load distribution were found to be reasonable in comparison to the assumed design values....

  8. Hybrid composites

    CSIR Research Space (South Africa)

    Jacob John, Maya

    2009-04-01

    Full Text Available effect was observed for the elongation at break of the hybrid composites. The impact strength of the hybrid composites increased with the addition of glass fibres. The tensile and impact properties of thermoplastic natural rubber reinforced short... panels made from conventional structural materials. Figure 3 illustrates the performance of cellular biocomposite panels against conventional systems used for building and residential construction, namely a pre- cast pre-stressed hollow core concrete...

  9. Wind-solar Hybrid Power System

    OpenAIRE

    Jin, Fei

    2014-01-01

    In the development and utilization of new energy sources, the solar energy and wind energy are paid more attention by various countries, and have become a new field of energy development and utilization of the highest level, the most mature technology, the most widely used and commercial development conditions for new energy. But both the traditional wind power system and solar power system have the characteristic of energy instability. Therefore, wind-solar hybrid power system was proposed i...

  10. Mathematical Modeling of Hybrid Electrical Engineering Systems

    Directory of Open Access Journals (Sweden)

    A. A. Lobaty

    2016-01-01

    Full Text Available A large class of systems that have found application in various industries and households, electrified transportation facilities and energy sector has been classified as electrical engineering systems. Their characteristic feature is a combination of continuous and discontinuous modes of operation, which is reflected in the appearance of a relatively new term “hybrid systems”. A wide class of hybrid systems is pulsed DC converters operating in a pulse width modulation, which are non-linear systems with variable structure. Using various methods for linearization it is possible to obtain linear mathematical models that rather accurately simulate behavior of such systems. However, the presence in the mathematical models of exponential nonlinearities creates considerable difficulties in the implementation of digital hardware. The solution can be found while using an approximation of exponential functions by polynomials of the first order, that, however, violates the rigor accordance of the analytical model with characteristics of a real object. There are two practical approaches to synthesize algorithms for control of hybrid systems. The first approach is based on the representation of the whole system by a discrete model which is described by difference equations that makes it possible to synthesize discrete algorithms. The second approach is based on description of the system by differential equations. The equations describe synthesis of continuous algorithms and their further implementation in a digital computer included in the control loop system. The paper considers modeling of a hybrid electrical engineering system using differential equations. Neglecting the pulse duration, it has been proposed to describe behavior of vector components in phase coordinates of the hybrid system by stochastic differential equations containing generally non-linear differentiable random functions. A stochastic vector-matrix equation describing dynamics of the

  11. Thermal properties of oil palm nano filler/kenaf reinforced epoxy hybrid nanocomposites

    Science.gov (United States)

    Saba, N.; Paridah, M. T.; Abdan, K.; Ibrahim, N. A.

    2016-11-01

    The aim of this research study was to fabricate nano oil palm empty fruit bunch (OPEFB)/kenaf/epoxy hybrid nanocomposites and to make comparative study on the thermal properties of nano OPEFB/kenaf/epoxy hybrid nanocomposites with the montmorillonite (MMT)/kenaf/epoxy hybrid nanocomposites and organically modified MMT (OMMT)/kenaf/epoxy hybrid nanocomposites. Epoxy based kenaf hybrid nanocomposites was prepared by dispersing the nano filler (nano OPEFB filler, MMT, OMMT) at 3% loading through high speed mechanical stirrer followed by hand lay-up technique. Thermal properties of hybrid nanocomposites were analyzed through thermogravimetry analyzer (TGA), and differential scanning calorimetry (DSC). Obtained results specified that addition of nano OPEFB filler improves the thermal stability and char yield of kenaf/epoxy composites. Furthermore, the increase in decomposition temperature by the nano OPEFB filler was quite comparable to the MMT/kenaf/epoxy but relatively less than OMMT/kenaf/epoxy hybrid nanocomposites. We concluded from overall consequences that the nano OPEFB filler can be used as the promising and innovative alternative of existing expensive nano filler, with relatively lesser impact on the environment having marked pronounced impact on the construction, automotive, aerospace, electronics and semiconducting sectors as future industries based on bio-wastes with satisfactory light weight and thermal stability on other side.

  12. Detection of cardiovascular anomalies: Hybrid systems approach

    KAUST Repository

    Ledezma, Fernando

    2012-06-06

    In this paper, we propose a hybrid interpretation of the cardiovascular system. Based on a model proposed by Simaan et al. (2009), we study the problem of detecting cardiovascular anomalies that can be caused by variations in some physiological parameters, using an observerbased approach. We present the first numerical results obtained. © 2012 IFAC.

  13. Reinforcement of natural rubber hybrid composites based on marble sludge/Silica and marble sludge/rice husk derived silica

    Directory of Open Access Journals (Sweden)

    Khalil Ahmed

    2014-03-01

    Full Text Available A research has been carried out to develop natural rubber (NR hybrid composites reinforced with marble sludge (MS/Silica and MS/rice husk derived silica (RHS. The primary aim of this development is to scrutinize the cure characteristics, mechanical and swelling properties of such hybrid composite. The use of both industrial and agricultural waste such as marble sludge and rice husk derived silica has the primary advantage of being eco-friendly, low cost and easily available as compared to other expensive fillers. The results from this study showed that the performance of NR hybrid composites with MS/Silica and MS/RHS as fillers is extremely better in mechanical and swelling properties as compared with the case where MS used as single filler. The study suggests that the use of recently developed silica and marble sludge as industrial and agricultural waste is accomplished to provide a probable cost effective, industrially prospective, and attractive replacement to the in general purpose used fillers like china clay, calcium carbonate, and talc.

  14. Analysis of the mechanical and thermal properties of jute and glass fiber as reinforcement epoxy hybrid composites

    Energy Technology Data Exchange (ETDEWEB)

    Braga, R.A., E-mail: roney.braga@fiat.com.br [FIAT Automóveis S.A., Teardown, CEP 32530-000 Betim, MG (Brazil); Magalhaes, P.A.A., E-mail: pamerico@pucminas.br [PUC—MINAS, Instituto Politécnico, CEP 30535-610 Belo Horizonte, MG (Brazil)

    2015-11-01

    This work describes the study to investigate and compare the mechanical and thermal properties of raw jute and glass fiber reinforced epoxy hybrid composites. To improve the mechanical properties, jute fiber was hybridized with glass fiber. Epoxy resin, jute and glass fibers were laminated in three weight ratios (69/31/0, 68/25/7 and 64/18/19) respectively to form composites. The tensile, flexural, impact, density, thermal and water absorption tests were carried out using hybrid composite samples. This study shows that the addition of jute fiber and glass fiber in epoxy, increases the density, the impact energy, the tensile strength and the flexural strength, but decreases the loss mass in function of temperature and the water absorption. Morphological analysis was carried out to observe fracture behavior and fiber pull-out of the samples using scanning electron microscope. - Highlights: • The work is the study of the mechanical of raw jute and glass fiber with epoxy resin. • The mechanical properties increased with more proportions of glass fibers. • The density of E69-J31-V0 was the lower. • The flexural strength did not have a significant increase. • The water absorption of E69-J31-V0 was the best.

  15. Unidirectional Core-Shell Hybrids for Concrete Reinforcement - A preliminary Study

    Science.gov (United States)

    1994-02-01

    18, no. 1, Jan 1987, pp 13-23. 38. Z. Hashin and B.W. Rosen. "The elastic moduli of fiber-reinforced materials," Journal of Applied Mechanics, vol 31...MAT DIV. MATHEY, GAITHERSBURG. MD NEPTCO / RACZELOWSKI. PAWTUCKET. RI NEW ZEALAND CONCRETE RSCH ASSN / LIB, PORIRUA, NORTHWESTERN UNIVERSITY / BAZANT

  16. Hybrid Energy System Modeling in Modelica

    Energy Technology Data Exchange (ETDEWEB)

    William R. Binder; Christiaan J. J. Paredis; Humberto E. Garcia

    2014-03-01

    In this paper, a Hybrid Energy System (HES) configuration is modeled in Modelica. Hybrid Energy Systems (HES) have as their defining characteristic the use of one or more energy inputs, combined with the potential for multiple energy outputs. Compared to traditional energy systems, HES provide additional operational flexibility so that high variability in both energy production and consumption levels can be absorbed more effectively. This is particularly important when including renewable energy sources, whose output levels are inherently variable, determined by nature. The specific HES configuration modeled in this paper include two energy inputs: a nuclear plant, and a series of wind turbines. In addition, the system produces two energy outputs: electricity and synthetic fuel. The models are verified through simulations of the individual components, and the system as a whole. The simulations are performed for a range of component sizes, operating conditions, and control schemes.

  17. Compact Hybrid Automotive Propulsion System

    Science.gov (United States)

    Lupo, G.

    1986-01-01

    Power train proposed for experimental vehicle powered by internal combustion engine and electric motor. Intended for front-wheel drive automobile, power train mass produced using existing technology. System includes internal-combustion engine, electric motor, continuously variable transmission, torque converter, differential, and control and adjustment systems for electric motor and transmission. Continuously variable transmission integrated into hydraulic system that also handles power steering and power brakes. Batteries for electric motor mounted elsewhere in vehicle.

  18. Development of structural health monitoring and early warning system for reinforced concrete system

    Energy Technology Data Exchange (ETDEWEB)

    Iranata, Data, E-mail: iranata-data@yahoo.com, E-mail: data@ce.its.ac.id; Wahyuni, Endah [Civil Engineering Department, Institut Teknologi Sepuluh Nopember (ITS), Surabaya 60111 (Indonesia); Murtiadi, Suryawan [Civil Engineering Department, Universitas Mataram, Mataram 83125 (Indonesia); Widodo, Amien [Geophysical Engineering Department, Institut Teknologi Sepuluh Nopember (ITS), Surabaya 60111 (Indonesia); Riksakomara, Edwin; Sani, Nisfu Asrul [Information Systems Department, Institut Teknologi Sepuluh Nopember (ITS), Surabaya 60111 (Indonesia)

    2015-04-24

    Many buildings have been damaged due to earthquakes that occurred recently in Indonesia. The main cause of the damage is the large deformation of the building structural component cannot accommodate properly. Therefore, it is necessary to develop the Structural Health Monitoring System (SHMS) to measure precisely the deformation of the building structural component in the real time conditions. This paper presents the development of SHMS for reinforced concrete structural system. This monitoring system is based on deformation component such as strain of reinforcement bar, concrete strain, and displacement of reinforced concrete component. Since the deformation component has exceeded the limit value, the warning message can be sent to the building occupies. This warning message has also can be performed as early warning system of the reinforced concrete structural system. The warning message can also be sent via Short Message Service (SMS) through the Global System for Mobile Communications (GSM) network. Hence, the SHMS should be integrated with internet modem to connect with GSM network. Additionally, the SHMS program is verified with experimental study of simply supported reinforced concrete beam. Verification results show that the SHMS has good agreement with experimental results.

  19. The effects of steel fibre reinforced concrete on system ductility

    Directory of Open Access Journals (Sweden)

    Yilmaz, U. S.

    2007-03-01

    Full Text Available Steel fibre-reinforced concrete is being used extensively today in both field applications and experimental studies on concrete strength and ductility. The state of passive confinement generated by the fibre delays cracking and enhances ductility. The present paper reports on both experimental and analytical studies. In the former, a series of 16 steel-fibre reinforced concrete prismatic specimens were subjected to axial loads and the respective axial load-unit strain diagrams were subsequently plotted to determine the effect of steel fibres on reinforced concrete column ductility. Secondly, an analytical study was run to determine the additional ductility accruing to a frame system when steel fibres are included in the concrete. Analytical models were generated for 16 two-storey, single-span reinforced concrete frames. The columns in these frames were designed to the same characteristics as the specimens used in the experimental tests. Non-linear static (pushover analyses were performed for each frame to obtain load-displacement curves and determine the effect of steel fibres on reinforced concrete column ductility.El hormigón reforzado con fibra de acero se emplea actualmente tanto en obra como en los trabajos experimentales para estudiar la resistencia mecánica y ductilidad del hormigón. El estado de confinamiento pasivo producido por la fibra retrasa la fisuración y aumenta la ductilidad. El presente trabajo es de índole tanto experimental como analítica. En primer lugar, en la parte experimental se aplica una fuerza axial a 16 probetas prismáticas (160 x 160 x 840 mm de hormigón reforzado con fibra de acero para determinar su comportamiento, obteniéndose las curvas de fuerza axial-deformación unitaria correspondientes a partir de los resultados observados. A partir de una evaluación de dichos resultados experimentales, se determina el efecto que ejercen las fibras de acero sobre la ductilidad de las probetas de hormigón armado

  20. Fuzzy Lyapunov Reinforcement Learning for Non Linear Systems.

    Science.gov (United States)

    Kumar, Abhishek; Sharma, Rajneesh

    2017-03-01

    We propose a fuzzy reinforcement learning (RL) based controller that generates a stable control action by lyapunov constraining fuzzy linguistic rules. In particular, we attempt at lyapunov constraining the consequent part of fuzzy rules in a fuzzy RL setup. Ours is a first attempt at designing a linguistic RL controller with lyapunov constrained fuzzy consequents to progressively learn a stable optimal policy. The proposed controller does not need system model or desired response and can effectively handle disturbances in continuous state-action space problems. Proposed controller has been employed on the benchmark Inverted Pendulum (IP) and Rotational/Translational Proof-Mass Actuator (RTAC) control problems (with and without disturbances). Simulation results and comparison against a) baseline fuzzy Q learning, b) Lyapunov theory based Actor-Critic, and c) Lyapunov theory based Markov game controller, elucidate stability and viability of the proposed control scheme.

  1. Nuclear Hybrid Energy System Model Stability Testing

    Energy Technology Data Exchange (ETDEWEB)

    Greenwood, Michael Scott [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cetiner, Sacit M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Fugate, David W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-04-01

    A Nuclear Hybrid Energy System (NHES) uses a nuclear reactor as the basic power generation unit, and the power generated is used by multiple customers as combinations of thermal power or electrical power. The definition and architecture of a particular NHES can be adapted based on the needs and opportunities of different localities and markets. For example, locations in need of potable water may be best served by coupling a desalination plant to the NHES. Similarly, a location near oil refineries may have a need for emission-free hydrogen production. Using the flexible, multi-domain capabilities of Modelica, Argonne National Laboratory, Idaho National Laboratory, and Oak Ridge National Laboratory are investigating the dynamics (e.g., thermal hydraulics and electrical generation/consumption) and cost of a hybrid system. This paper examines the NHES work underway, emphasizing the control system developed for individual subsystems and the overall supervisory control system.

  2. Hybrid system of semiconductor and photosynthetic protein.

    Science.gov (United States)

    Kim, Younghye; Shin, Seon Ae; Lee, Jaehun; Yang, Ki Dong; Nam, Ki Tae

    2014-08-29

    Photosynthetic protein has the potential to be a new attractive material for solar energy absorption and conversion. The development of semiconductor/photosynthetic protein hybrids is an example of recent progress toward efficient, clean and nanostructured photoelectric systems. In the review, two biohybrid systems interacting through different communicating methods are addressed: (1) a photosynthetic protein immobilized semiconductor electrode operating via electron transfer and (2) a hybrid of semiconductor quantum dots and photosynthetic protein operating via energy transfer. The proper selection of materials and functional and structural modification of the components and optimal conjugation between them are the main issues discussed in the review. In conclusion, we propose the direction of future biohybrid systems for solar energy conversion systems, optical biosensors and photoelectric devices.

  3. Analysis of hybrid solar systems

    Science.gov (United States)

    Swisher, J.

    1980-10-01

    The TRNSYS simulation program was used to evaluate the performance of active charge/passive discharge solar systems with water as the working fluid. TRNSYS simulations are used to evaluate the heating performance and cooling augmentation provided by systems in several climates. The results of the simulations are used to develop a simplified analysis tool similar to the F-chart and Phi-bar procedures used for active systems. This tool, currently in a preliminary stage, should provide the designer with quantitative performance estimates for comparison with other passive, active, and nonsolar heating and cooling designs.

  4. New Tools for Hybrid Systems

    Science.gov (United States)

    2007-05-02

    IEEE Transactions on Automatic Control , vol. 48, no. 1, pp. 2-17, January 2003. [4] A. Megretski, "Robustness...34Output stabilizability of discrete-event dynamic systems", IEEE Transactions on Automatic Control , vol. 36, no.8, pp. 925-935, August 1991. [6] K...Passino, A. Michel and P. Antsaklis, "Lyapunov stability of a class of discrete event systems", IEEE Transactions on Automatic Control , vol. 39, no.

  5. Optimised Hybrid Integrated Renewable Energy System

    Directory of Open Access Journals (Sweden)

    Dr. Arun Sandilya

    2012-10-01

    Full Text Available A hybrid integrated renewable energy system for an isolated small community, where grid extension is considered uneconomical. This paper proposed cost optimization through dynamic matching between load and proper equipment sizing. The Matlab based computer program developed for determining the most cost effective energy source to supply required load any given time of the day. Integrated system based on green energy utilization and rural electricity development.

  6. Analysis of Synchronization for Coupled Hybrid Systems

    DEFF Research Database (Denmark)

    Li, Zheng; Wisniewski, Rafal

    2006-01-01

    In the control systems with coupled multi-subsystem, the subsystems might be synchronized (i.e. all the subsystems have the same operation states), which results in negative influence to the whole system. For example, in the supermarket refrigeration systems, the synchronized switch of each...... subsystem will cause low efficiency, inferior control performance and a high wear on the compressor. This paper takes the supermarket refrigeration systems as an example to analyze the synchronization and its coupling strengths of coupled hybrid systems, which may provide a base for further research...

  7. Biomolecule/nanomaterial hybrid systems for nanobiotechnology.

    Science.gov (United States)

    Tel-Vered, Ran; Yehezkeli, Omer; Willner, Itamar

    2012-01-01

    The integration of biomolecules with metallic or semiconductor nanoparticles or carbon nanotubes yields new hybrid nanostructures of unique features that combine the properties of the biomolecules and of the nano-elements. These unique features of the hybrid biomolecule/nanoparticle systems provide the basis for the rapid development of the area of nanobiotechnology. Recent advances in the implementation of hybrid materials consisting of biomolecules and metallic nanoparticles or semiconductor quantum dots will be discussed. The following topics will be exemplified: (i) The electrical wiring of redox enzymes with electrodes by means of metallic nanoparticles or carbon nanotubes, and the application of the modified electrodes as amperometric biosensors or for the construction of biofuel cells. (ii) The biocatalytic growth of metallic nanoparticles as a means to construct optical or electrical sensors. (iii) The functionalization of semiconductor quantum dots with biomolecules and the application of the hybrid nanostructures for developing different optical sensors, including intracellular sensor systems. (iv) The use of biomolecule-metallic nanoparticle nanostructures as templates for growing metallic nanowires, and the construction of fuel-driven nano-transporters.

  8. Disease processes as hybrid dynamical systems

    Directory of Open Access Journals (Sweden)

    Pietro Liò

    2012-08-01

    Full Text Available We investigate the use of hybrid techniques in complex processes of infectious diseases. Since predictive disease models in biomedicine require a multiscale approach for understanding the molecule-cell-tissue-organ-body interactions, heterogeneous methodologies are often employed for describing the different biological scales. Hybrid models provide effective means for complex disease modelling where the action and dosage of a drug or a therapy could be meaningfully investigated: the infection dynamics can be classically described in a continuous fashion, while the scheduling of multiple treatment discretely. We define an algebraic language for specifying general disease processes and multiple treatments, from which a semantics in terms of hybrid dynamical system can be derived. Then, the application of control-theoretic tools is proposed in order to compute the optimal scheduling of multiple therapies. The potentialities of our approach are shown in the case study of the SIR epidemic model and we discuss its applicability on osteomyelitis, a bacterial infection affecting the bone remodelling system in a specific and multiscale manner. We report that formal languages are helpful in giving a general homogeneous formulation for the different scales involved in a multiscale disease process; and that the combination of hybrid modelling and control theory provides solid grounds for computational medicine.

  9. Wear Characteristics of Hybrid Composites Based on Za27 Alloy Reinforced With Silicon Carbide and Graphite Particles

    Directory of Open Access Journals (Sweden)

    S. Mitrović

    2014-06-01

    Full Text Available The paper presents the wear characteristics of a hybrid composite based on zinc-aluminium ZA27 alloy, reinforced with silicon-carbide and graphite particles. The tested sample contains 5 vol.% of SiC and 3 vol.% Gr particles. Compocasting technique has been used to prepare the samples. The experiments were performed on a “block-on-disc” tribometer under conditions of dry sliding. The wear volumes of the alloy and the composite were determined by varying the normal loads and sliding speeds. The paper contains the procedure for preparation of sample composites and microstructure of the composite material and the base ZA27 alloy. The wear surface of the composite material was examined using the scanning electronic microscope (SEM and energy dispersive spectrometry (EDS. Conclusions were obtained based on the observed impact of the sliding speed, normal load and sliding distance on tribological behaviour of the observed composite.

  10. Experimental Test of Stainless Steel Wire Mesh and Aluminium Alloy With Glass Fiber Reinforcement Hybrid Composite

    OpenAIRE

    2015-01-01

    At present, composite materials are mostly used in aircraft structural components, because of their excellent properties like lightweight, high strength to weight ratio, high stiffness, and corrosion resistance and less expensive. In this experimental work, the mechanical properties of laminate, this is reinforced with stainless steel wire mesh, aluminum sheet metal, perforated aluminum sheet metal and glass fibers to be laminate and investigated. The stainless steel wire mesh and...

  11. Universal blind quantum computation for hybrid system

    Science.gov (United States)

    Huang, He-Liang; Bao, Wan-Su; Li, Tan; Li, Feng-Guang; Fu, Xiang-Qun; Zhang, Shuo; Zhang, Hai-Long; Wang, Xiang

    2017-08-01

    As progress on the development of building quantum computer continues to advance, first-generation practical quantum computers will be available for ordinary users in the cloud style similar to IBM's Quantum Experience nowadays. Clients can remotely access the quantum servers using some simple devices. In such a situation, it is of prime importance to keep the security of the client's information. Blind quantum computation protocols enable a client with limited quantum technology to delegate her quantum computation to a quantum server without leaking any privacy. To date, blind quantum computation has been considered only for an individual quantum system. However, practical universal quantum computer is likely to be a hybrid system. Here, we take the first step to construct a framework of blind quantum computation for the hybrid system, which provides a more feasible way for scalable blind quantum computation.

  12. Microstructure and Mechanical Behaviour of Stir-Cast Al-Mg-Sl Alloy Matrix Hybrid Composite Reinforced with Corn Cob Ash and Silicon Carbide

    Directory of Open Access Journals (Sweden)

    Oluwagbenga Babajide Fatile

    2014-10-01

    Full Text Available In this present study, the microstructural and mechanical behaviour of Al-Mg-Si alloy matrix composites reinforced with silicon carbide (SiC and Corn cob ash (An agro‑waste was investigated. This research work was aimed at assessing the suitability of developing low cost- high performance Al-Mg-Si hybrid composite. Silicon carbide (SiC particulates added with 0,1,2,3 and 4 wt% Corn cob ash (CCA were utilized to prepare 10 wt% of the reinforcing phase with Al-Mg-Si alloy as matrix using two-step stir casting method. Microstructural characterization, density measurement, estimated percent porosity, tensile testing, and micro‑hardness measurement were used to characterize the composites produced. From the results obtained, CCA has great potential to serve as a complementing reinforcement for the development of low cost‑high performance aluminum hybrid composites.

  13. Mechanical properties and fabrication of small boat using woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite

    Science.gov (United States)

    Misri, S.; Leman, Z.; Sapuan, S. M.; Ishak, M. R.

    2010-05-01

    In recent years, sugar palm fibre has been found to have great potential to be used as fibre reinforcement in polymer matrix composites. This research investigates the mechanical properties of woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite. The composite specimens made of different layer of fibres such as strand mat, natural and hand woven of sugar palm fibres. The composites were fabricated using a compression moulding technique. The tensile and impact test was carried out in accordance to ASTM 5083 and ASTM D256 standard. The fibre glass boat is a familiar material used in boat industry. A lot of research on fabrication process such as lay-up, vacuum infusion mould and resin transfer mould has been conducted. Hybrid material of sugar palm fibre and fibre glass was used in fabricating the boat. This research investigates the method selection for fabrication of small boat application of natural fibre composites. The composite specimens made of different layer of fibres; woven glass fibre, strand mat, natural and hand woven of woven sugar palm fibres were prepared. The small boat were fabricated using a compression moulding and lay up technique. The results of the experiment showed that the tensile strength, tensile modulus, elongation at break value and impact strength were higher than the natural woven sugar palm fibre. The best method for fabricating the small boat was compression moulding technique. As a general conclusion, the usage of glass fibre had improved the tensile properties sugar palm fibre composites and compression moulding technique is suitable to be used in making a small boat application of natural fibre composites.

  14. Thermo-mechanical characterization of siliconized E-glass fiber/hematite particles reinforced epoxy resin hybrid composite

    Energy Technology Data Exchange (ETDEWEB)

    Arun Prakash, V.R., E-mail: vinprakash101@gmail.com; Rajadurai, A., E-mail: rajadurai@annauniv.edu.in

    2016-10-30

    Highlights: • Particles dimension have reduced using Ball milling process. • Importance of surface modification was explored. • Surface modification has been done to improve adhesion of fiber/particles with epoxy. • Mechanical properties has been increased by adding modified fiber and particles. • Thermal properties have been increased. - Abstract: In this present work hybrid polymer (epoxy) matrix composite has been strengthened with surface modified E-glass fiber and iron(III) oxide particles with varying size. The particle sizes of 200 nm and <100 nm has been prepared by high energy ball milling and sol-gel methods respectively. To enhance better dispersion of particles and improve adhesion of fibers and fillers with epoxy matrix surface modification process has been done on both fiber and filler by an amino functional silane 3-Aminopropyltrimethoxysilane (APTMS). Crystalline and functional groups of siliconized iron(III) oxide particles were characterized by XRD and FTIR spectroscopy analysis. Fixed quantity of surface treated 15 vol% E-glass fiber was laid along with 0.5 and 1.0 vol% of iron(III) oxide particles into the matrix to fabricate hybrid composites. The composites were cured by an aliphatic hardener Triethylenetetramine (TETA). Effectiveness of surface modified particles and fibers addition into the resin matrix were revealed by mechanical testing like tensile testing, flexural testing, impact testing, inter laminar shear strength and hardness. Thermal behavior of composites was evaluated by TGA, DSC and thermal conductivity (Lee’s disc). The scanning electron microscopy was employed to found shape and size of iron(III) oxide particles adhesion quality of fiber with epoxy matrix. Good dispersion of fillers in matrix was achieved with surface modifier APTMS. Tensile, flexural, impact and inter laminar shear strength of composites was improved by reinforcing surface modified fiber and filler. Thermal stability of epoxy resin was improved

  15. Mechanical Behaviour ofAl2014 Reinforced with Boron Carbide and Short Basalt Fiber Based Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Ranganatha S R

    2016-09-01

    Full Text Available The present study was aimed at evaluating the effect of short Basalt Fiber and B4Con hardness and impact strength of Al 2014 Composites. These AMCs with individual and multiple reinforcement (hybrid MMCs are finding increased applications in aerospace, automobile, space, underwater and transportation applications. An effort is made to enhance the Hardness and Impact properties of AMCs by reinforcing Al2014 matrix with Varying Proportion of Short basalt fiber and Boron carbide by stir casting method. Aluminum alloy matrix varying proportions of boron carbide particulates and Short Basalt fibers were fabricated. The microstructure,hardness and impact strength properties of the fabricated AMCs were analyzed. The optical microstructure study revealed the homogeneous dispersion of B4C particles and Short Basalt fiber in the matrix. Based on the results obtained from the Hardness and Impact of the metal matrix composites it is observed that, the hardness and impact strength increases with increase in the amount of reinforcement‘s.

  16. Microstructures and properties of graphite and Al2O3 short fibers reinforced Mg-Al-Zn alloy hybrid composites

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao-hong; LIU Yong-bing; SONG Qi-fei; AN Jian

    2006-01-01

    Graphite and Al2O3 short fibers reinforced Mg-Al-Zn alloy hybrid composites were fabricated by perform squeeze-infiltration route. The effects of the volume of graphite particles on the microstructure, mechanical properties and tribological behavior were investigated under the conditions of constant size of graphite particle and volume of Al2O3 short fiber. The results reveal that the uniform distribution of the reinforced graphite particles and Al2O3 short fiber can be obtained by this technique, and they have strong bonding with the metal matrix. Increasing graphite volume results in decrease in hardness, the ultimate tensile strength whereas the Al2O3 short fiber makes contribution to the increase in hardness of the composite. The composite exhibits good wear resistance, small wear mass loss and low coefficient of friction as compared with the metal matrix. The wear mechanisms transit from oxidation wear, abrasion wear into delamination wear as the applied load is increased, and a film of lubricant covering almost entire surface of specimen, is found to be formed, which separates the wear surfaces from metal to metal contact and thus improves the tribological properties.

  17. EVALUATION & COMPARISION OF MECHANICAL PROPERTIES OF ALUMINIUM ALLOY 5052 REINFORCED WITH SILICONCARBIDE, GRAPHITE AND FLY ASH HYBRID METAL MATRIX COMPOSITES

    Directory of Open Access Journals (Sweden)

    ANKUSH SACHDEVA

    2013-10-01

    Full Text Available The engineering fraternity has always been looking forward to develop an outstanding and wonder-materials which would fit the ever-changing demands of the world. In order to fullfill the demands various newdiscoveries have been made by scientists, engineers and resrearchers. In todays competitive world many, materials have been tried for various unexplored conditions , but the never ending demand of the world encourages the researchers to develop the new material. Now the researchers are preparing the material by the combination of different materials called hybrid composite material.. Metal Matrix Composites (MMCs have emerged as a class of materials suitable for structural, aerospace, automotive, electronic, thermal and wearapplications owing to their advantages over the conventional materials. The present study was taken up to explore the possibility of using different reinforcements (silicon carbide, fly ash and graphite to enhance the properties of aluminium alloy (Al5052 composites. Different samples were prepared from the aluminium withvarying reinforcement composition. The mechanical properties studied after the experiment were strength, hardness and elongation.Further, these composites were characterized with the help of, mechanical testing and scanning electron microscopy.

  18. Hybrid compensation arrangement in dispersed generation systems

    DEFF Research Database (Denmark)

    Chen, Zhe; Blaabjerg, Frede; Pedersen, John Kim

    2005-01-01

    This paper presents a hybrid compensation system consisting of an active filter and distributed passive filters. In the system, each individual passive filter is connected to a distortion source and designed to eliminate main harmonics and supply reactive power for the distortion source, while...... are performed for a power system including the dispersed generation units connected into the system through power electronic converters and diode rectifier loads, which produce the distorted waveforms. The simulation results have demonstrated that good compensation effects can be achieved by using the combined...

  19. Hybrid ventilation systems and high performance buildings

    Energy Technology Data Exchange (ETDEWEB)

    Utzinger, D.M. [Wisconsin Univ., Milwaukee, WI (United States). School of Architecture and Urban Planning

    2009-07-01

    This paper described hybrid ventilation design strategies and their impact on 3 high performance buildings located in southern Wisconsin. The Hybrid ventilation systems combined occupant controlled natural ventilation with mechanical ventilation systems. Natural ventilation was shown to provide adequate ventilation when appropriately designed. Proper control integration of natural ventilation into hybrid systems was shown to reduce energy consumption in high performance buildings. This paper also described the lessons learned from the 3 buildings. The author served as energy consultant on all three projects and had the responsibility of designing and integrating the natural ventilation systems into the HVAC control strategy. A post occupancy evaluation of building energy performance has provided learning material for architecture students. The 3 buildings included the Schlitz Audubon Nature Center completed in 2003; the Urban Ecology Center completed in 2004; and the Aldo Leopold Legacy Center completed in 2007. This paper included the size, measured energy utilization intensity and percentage of energy supplied by renewable solar power and bio-fuels on site for each building. 6 refs., 2 tabs., 6 figs.

  20. Viewing hybrid systems as products of control systems and automata

    Science.gov (United States)

    Grossman, R. L.; Larson, R. G.

    1992-01-01

    The purpose of this note is to show how hybrid systems may be modeled as products of nonlinear control systems and finite state automata. By a hybrid system, we mean a network of consisting of continuous, nonlinear control system connected to discrete, finite state automata. Our point of view is that the automata switches between the control systems, and that this switching is a function of the discrete input symbols or letters that it receives. We show how a nonlinear control system may be viewed as a pair consisting of a bialgebra of operators coding the dynamics, and an algebra of observations coding the state space. We also show that a finite automata has a similar representation. A hybrid system is then modeled by taking suitable products of the bialgebras coding the dynamics and the observation algebras coding the state spaces.

  1. Nanoclay reinforced thermoplastic toughened epoxy hybrid syntactic foam: Surface morphology, mechanical and thermo mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Asif, A. [Propellants and Special Chemicals Group, Propellants Polymers Chemicals and Materials Entity, Vikram Sarabhai Space Centre, Trivandrum 695022 (India); Rao, V. Lakshmana, E-mail: rao_vl@yahoo.co.in [Propellants and Special Chemicals Group, Propellants Polymers Chemicals and Materials Entity, Vikram Sarabhai Space Centre, Trivandrum 695022 (India); Ninan, K.N. [Propellants and Special Chemicals Group, Propellants Polymers Chemicals and Materials Entity, Vikram Sarabhai Space Centre, Trivandrum 695022 (India)

    2010-09-15

    Epoxy hybrid syntactic foams were prepared with diglycidyl ether of bisphenol A (DGEBA) epoxy resin, diamino diphenyl sulfone (DDS), hydroxyl terminated polyether ether ketone having pendant methyl group (PEEKMOH), microballoon and nanoclay. The density of the foam was maintained between 0.6 and 0.72 g/cc for all compositions. Fracture toughness, tensile, flexural and compressive properties of the foam were evaluated with respect to clay and PEEKMOH concentrations. Morphology by X-ray diffraction revealed that the clay particles within the epoxy resin were intercalated for all the compositions of the syntactic foam. Fracture toughness and mechanical properties of the syntactic foam were significantly improved by the addition of nanoclay. A further enhancement in fracture toughness and mechanical properties was observed by the addition of PEEKMOH. The hybrid epoxy syntactic foam thus prepared exhibited 58%, 77% and 38% improvement in compressive strength, percentage elongation and fracture toughness, respectively, compared to the neat epoxy syntactic foam. The specific mechanical properties were found to be higher for the epoxy hybrid syntactic foam containing 3 wt% nanoclay and 3 wt% of PEEKMOH combination. The storage and loss modulus of the syntactic foam were also increased by the addition of nanoclay and PEEKMOH. A marginal improvement in T{sub g} was observed with clay incorporated syntactic foam. SEM analysis revealed that increased microcracking, crack path deflection, matrix deformation, plastic deformation, rupture of microballoons and debonded microspheres influencing on fracture toughness and mechanical properties of epoxy hybrid syntactic foam.

  2. Future hybrid systems: solar and hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Kazmerski, L.L. [National Renewable Energy Lab., Golden, CO (United States); Broussard, K. [National Renewable Energy Lab., Golden, CO (United States)]|[NREL MURA Intern from Southern Univ., Baton Rouge, LA (United States)

    2003-07-01

    Future solar and hydrogen hybrid systems are discussed in terms of the evolving hydrogen economy. The focus is on distributed hydrogen, relying on the same distributed-energy strengths of solar-photovoltaic electricity in the built environment. Solar-hydrogen residences, as well as solar parks, are presented. Landarea issues are evaluated, and the economics and potential of these approaches are examined in terms of roadmap predictions on PV and hydrogen pathways. (orig.)

  3. Spectral Selectivity Applied To Hybrid Concentration Systems

    Science.gov (United States)

    Hamdy, M. A.; Luttmann, F.; Osborn, D. E.; Jacobson, M. R.; MacLeod, H. A.

    1985-12-01

    The efficiency of conversion of concentrated solar energy can be improved by separating the solar spectrum into portions matched to specific photoquantum processes and the balance used for photothermal conversion. The basic approaches of spectrally selective beam splitters are presented. A detailed simulation analysis using TRNSYS is developed for a spectrally selective hybrid photovoltaic/photothermal concentrating system. The analysis shows definite benefits to a spectrally selective approach.

  4. Development of Hybrid Braided Composite Rods for Reinforcement and Health Monitoring of Structures

    OpenAIRE

    Sohel Rana; Emilija Zdraveva; Cristiana Pereira; Raul Fangueiro; A. Gomes Correia

    2014-01-01

    In the present study, core-reinforced braided composite rods (BCRs) were developed and characterized for strain sensing capability. A mixture of carbon and glass fibre was used in the core, which was surrounded by a braided cover of polyester fibres. Three compositions of core with different carbon fibre/glass fibre weight ratios (23/77, 47/53, and 100/0) were studied to find out the optimum composition for both strain sensitivity and mechanical performance. The influence of carbon f...

  5. Micromechanical analysis of a hybrid composite—effect of boron carbide particles on the elastic properties of basalt fiber reinforced polymer composite

    Science.gov (United States)

    Krishna Golla, Sai; Prasanthi, P.

    2016-11-01

    A fiber reinforced polymer (FRP) composite is an important material for structural application. The diversified application of FRP composites has become the center of attention for interdisciplinary research. However, improvements in the mechanical properties of this class of materials are still under research for different applications. The reinforcement of inorganic particles in a composite improves its structural properties due to their high stiffness. The present research work is focused on the prediction of the mechanical properties of the hybrid composites where continuous fibers are reinforced in a micro boron carbide particle mixed polypropylene matrix. The effectiveness of the addition of 30 wt. % of boron carbide (B4C) particle contributions regarding the longitudinal and transverse properties of the basalt fiber reinforced polymer composite at various fiber volume fractions is examined by finite element analysis (FEA). The experimental approach is the best way to determine the properties of the composite but it is expensive and time-consuming. Therefore, the finite element method (FEM) and analytical methods are the viable methods for the determination of the composite properties. The FEM results were obtained by adopting a micromechanics approach with the support of FEM. Assuming a uniform distribution of reinforcement and considering one unit-cell of the whole array, the properties of the composite materials are determined. The predicted elastic properties from FEA are compared with the analytical results. The results suggest that B4C particles are a good reinforcement for the enhancement of the transverse properties of basalt fiber reinforced polypropylene.

  6. An Improved Reinforcement Learning System Using Affective Factors

    Directory of Open Access Journals (Sweden)

    Takashi Kuremoto

    2013-07-01

    Full Text Available As a powerful and intelligent machine learning method, reinforcement learning (RL has been widely used in many fields such as game theory, adaptive control, multi-agent system, nonlinear forecasting, and so on. The main contribution of this technique is its exploration and exploitation approaches to find the optimal solution or semi-optimal solution of goal-directed problems. However, when RL is applied to multi-agent systems (MASs, problems such as “curse of dimension”, “perceptual aliasing problem”, and uncertainty of the environment constitute high hurdles to RL. Meanwhile, although RL is inspired by behavioral psychology and reward/punishment from the environment is used, higher mental factors such as affects, emotions, and motivations are rarely adopted in the learning procedure of RL. In this paper, to challenge agents learning in MASs, we propose a computational motivation function, which adopts two principle affective factors “Arousal” and “Pleasure” of Russell’s circumplex model of affects, to improve the learning performance of a conventional RL algorithm named Q-learning (QL. Compared with the conventional QL, computer simulations of pursuit problems with static and dynamic preys were carried out, and the results showed that the proposed method results in agents having a faster and more stable learning performance.

  7. CHAOS THEORY, GLOBAL SYSTEMIC CHANGE, AND HYBRID WARS

    Directory of Open Access Journals (Sweden)

    A. Korybko

    2016-01-01

    Full Text Available The global system is being rocked by the dueling ambitions of two competing blocs, with the US and its allies fighting to reinforce their unipolar system while Russia and its partners struggle to forge a multipolar future. The rapidity and scope with which events are unfolding makes it overwhelming for the casual observer to make sense of all of the complex processes currently at play, and truth be told, it’s understandable that all of this can appear confusing. In an attempt to clarify the present state of global affairs and forecast the direction that it’s all headed in, the article begins by explaining the nature of chaos theory and describing how it’s applicable to conceptualizing contemporary international relations. Afterwards, the idea of “chaos sequencing” is proposed, which in essence is a model that can be used in understanding the process of chaotic change. Following that, the article addresses the topic of global systemic change and includes the most relevant examples for how this relates to the present day. Next, the research combines these two aforementioned elements (chaos theory and global systemic change and presents a forward-looking geopolitical analysis that incorporates cutting-edge Hybrid War theory and aims to put the New Cold War into its proper perspective. Finally, the article ends on a suggestive note in encouraging analysts to study the authors’ conceptualization of Hybrid War in order to better prepare themselves for understanding and responding to forthcoming international events.

  8. Hybrid2: The hybrid system simulation model, Version 1.0, user manual

    Energy Technology Data Exchange (ETDEWEB)

    Baring-Gould, E.I.

    1996-06-01

    In light of the large scale desire for energy in remote communities, especially in the developing world, the need for a detailed long term performance prediction model for hybrid power systems was seen. To meet these ends, engineers from the National Renewable Energy Laboratory (NREL) and the University of Massachusetts (UMass) have spent the last three years developing the Hybrid2 software. The Hybrid2 code provides a means to conduct long term, detailed simulations of the performance of a large array of hybrid power systems. This work acts as an introduction and users manual to the Hybrid2 software. The manual describes the Hybrid2 code, what is included with the software and instructs the user on the structure of the code. The manual also describes some of the major features of the Hybrid2 code as well as how to create projects and run hybrid system simulations. The Hybrid2 code test program is also discussed. Although every attempt has been made to make the Hybrid2 code easy to understand and use, this manual will allow many organizations to consider the long term advantages of using hybrid power systems instead of conventional petroleum based systems for remote power generation.

  9. Macroscopic Mechanical Characterization of SMAs Fiber-Reinforced Hybrid Composite Under Uniaxial Loading

    Science.gov (United States)

    Lei, Hongshuai; Wang, Zhenqing; Tong, Liyong; Tang, Xiaojun

    2013-10-01

    This paper presents an experimental and theoretical investigation on the macroscopic mechanical behavior of shape memory alloys (SMAs) fiber-reinforced glass/resin composite subject to uniaxial loading at ambient temperature. A series of unidirectional SMAs reinforced composite laminates is fabricated through vacuum-assisted resin injection. Scanning electron microscopy is conducted to evaluate the interfacial cohesive quality between SMAs fiber and matrix. A theoretical model is proposed based on the SMAs phase transformation model and rule of mixture. Uniaxial tensile tests are performed to study the effects of weak interface and SMAs fiber volume fraction on the effective modulus of composite. Failure morphology of composite is discussed based on the observation using digital HF microscope. Due to the effects of phase transformation and weak interface, the overall stiffness of SMAs composite at the second stage is on average 10% lower than theoretical results. The rupture elongation of experimental result is approximately 13% higher than theoretical result. The local interfacial debonding between SMAs fiber and glass/resin matrix is the main failure mode.

  10. Development of Hybrid Braided Composite Rods for Reinforcement and Health Monitoring of Structures

    Directory of Open Access Journals (Sweden)

    Sohel Rana

    2014-01-01

    Full Text Available In the present study, core-reinforced braided composite rods (BCRs were developed and characterized for strain sensing capability. A mixture of carbon and glass fibre was used in the core, which was surrounded by a braided cover of polyester fibres. Three compositions of core with different carbon fibre/glass fibre weight ratios (23/77, 47/53, and 100/0 were studied to find out the optimum composition for both strain sensitivity and mechanical performance. The influence of carbon fibre positioning in BCR cross-section on the strain sensing behaviour was also investigated. Strain sensing property of BCRs was characterized by measuring the change in electrical resistance with flexural strain. It was observed that BCRs exhibited increase (positive response or decrease (negative response in electrical resistance depending on carbon fibre positioning. The BCR with lowest amount of carbon fibre was found to give the best strain sensitivity as well as the highest tensile strength and breaking extension. The developed BCRs showed reversible strain sensing behaviour under cyclic flexural loading with a maximum gauge factor of 23.4 at very low strain level (0.55%. Concrete beams reinforced with the optimum BCR (23/77 also exhibited strain sensing under cyclic flexural strain, although the piezoresistive behaviour in this case was irreversible.

  11. Advanced propulsion system for hybrid vehicles

    Science.gov (United States)

    Norrup, L. V.; Lintz, A. T.

    1980-01-01

    A number of hybrid propulsion systems were evaluated for application in several different vehicle sizes. A conceptual design was prepared for the most promising configuration. Various system configurations were parametrically evaluated and compared, design tradeoffs performed, and a conceptual design produced. Fifteen vehicle/propulsion systems concepts were parametrically evaluated to select two systems and one vehicle for detailed design tradeoff studies. A single hybrid propulsion system concept and vehicle (five passenger family sedan)were selected for optimization based on the results of the tradeoff studies. The final propulsion system consists of a 65 kW spark-ignition heat engine, a mechanical continuously variable traction transmission, a 20 kW permanent magnet axial-gap traction motor, a variable frequency inverter, a 386 kg lead-acid improved state-of-the-art battery, and a transaxle. The system was configured with a parallel power path between the heat engine and battery. It has two automatic operational modes: electric mode and heat engine mode. Power is always shared between the heat engine and battery during acceleration periods. In both modes, regenerative braking energy is absorbed by the battery.

  12. A general purpose characterization system for rooftop hybrid microconcentrators

    Science.gov (United States)

    Middleton, Robert; Jones, Christopher; Thomsen, Elizabeth; Diez, Vicente Munoz; Harvey, J.; Everett, Vernie; Blakers, Andrew

    2014-09-01

    A versatile characterization system for hybrid thermal and photovoltaic solar receivers is presented and demonstrated. The characterization of the thermal loss and effective area of a novel hybrid receiver is presented.

  13. Cultural Change, the Hybrid Administrative System and Public ...

    African Journals Online (AJOL)

    2013-01-17

    Jan 17, 2013 ... crackdown on corruption, this article explores the view that it is the hybrid .... decentralization and public participation in governance creates new demands. ..... The Hybrid Administrative System and Corporate Culture.

  14. Hybrid modeling and prediction of dynamical systems

    Science.gov (United States)

    Lloyd, Alun L.; Flores, Kevin B.

    2017-01-01

    Scientific analysis often relies on the ability to make accurate predictions of a system’s dynamics. Mechanistic models, parameterized by a number of unknown parameters, are often used for this purpose. Accurate estimation of the model state and parameters prior to prediction is necessary, but may be complicated by issues such as noisy data and uncertainty in parameters and initial conditions. At the other end of the spectrum exist nonparametric methods, which rely solely on data to build their predictions. While these nonparametric methods do not require a model of the system, their performance is strongly influenced by the amount and noisiness of the data. In this article, we consider a hybrid approach to modeling and prediction which merges recent advancements in nonparametric analysis with standard parametric methods. The general idea is to replace a subset of a mechanistic model’s equations with their corresponding nonparametric representations, resulting in a hybrid modeling and prediction scheme. Overall, we find that this hybrid approach allows for more robust parameter estimation and improved short-term prediction in situations where there is a large uncertainty in model parameters. We demonstrate these advantages in the classical Lorenz-63 chaotic system and in networks of Hindmarsh-Rose neurons before application to experimentally collected structured population data. PMID:28692642

  15. Hybrid Fiber Sizings for Enhanced Energy Absorption in Glass-Reinforced Composites

    Science.gov (United States)

    2006-01-01

    diameter of 22 nm was added to the fiber-sizing package. In all cases, a water-dispersible diglycidyl ether of bisphenol A epoxy ( DGEBA ) was...roughening agent. Fiber Sizing Silanes Film Former Roughening Agent Hybrid GPS PTMO DGEBA epoxy dispersion Water dispersible colloidal silica...Compatible GPS DGEBA epoxy dispersion None Mixed GPS PTMO DGEBA epoxy dispersion None Incompatible PTMO DGEBA epoxy dispersion None 2.2 Roving Strength

  16. MECHANICAL BEHAVIOUR OF ABACA-GLASS-BANANA FIBRE REINFORCED HYBRID COMPOSITES

    Directory of Open Access Journals (Sweden)

    H. VENKATASUBRAMANIAN

    2015-08-01

    Full Text Available Hybrid composites comprising of natural and synthetic fibres with phenolic resin is one of the present composite manufacturing techniques for achieving enhanced mechanical properties. In this study Abaca-banana-glass composites has been fabricated and its mechanical properties were analysed. Tensile, flexural and impact strength were investigated in the process of mechanical characterisation. Matrix material used is a phenolic resin of Ortho-Phthalic acid. The manufacture of the composite is done by hand layup technique where the fibre content is varied through volume fraction of 0.4 to 0.5. Setup is arranged in such a way that glass fibre is arranged on the top and bottom layers of the laminate which adds up strength and produces a better surface finish, where in the natural fibre is sandwiched in intermediate layers within the glass fibre. Fibre orientation and the detailed internal structure of matrix were studied by using SEM photography. The results showed that Abaca-banana-glass hybrid composite has better tensile property, Banana-glass composite has the best flexural property and Abaca-glass composite has the best impact property. The results obtained show a substantial increase in mechanical properties and hence these hybrid composites can be used as an effective alternative for synthetic fibres and can be used as an alternate for different industrial application.

  17. Differential dynamic logics - automated theorem proving for hybrid systems

    OpenAIRE

    Platzer, André

    2008-01-01

    Hybrid systems are models for complex physical systems and are defined as dynamical systems with interacting discrete transitions and continuous evolutions along differential equations. With the goal of developing a theoretical and practical foundation for deductive verification of hybrid systems, we introduce differential dynamic logic as a new logic with which correctness properties of hybrid systems with parameterized system dynamics can be specified and verified naturally. As a verificati...

  18. 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: PR-

  19. Advanced hybrid vehicle propulsion system study

    Science.gov (United States)

    Schwarz, R.

    1982-01-01

    Results are presented of a study of an advanced heat engine/electric automotive hybrid propulsion system. The system uses a rotary stratified charge engine and ac motor/controller in a parallel hybrid configuration. The three tasks of the study were (1) parametric studies involving five different vehicle types, (2) design trade-off studies to determine the influence of various vehicle and propulsion system paramaters on system performance fuel economy and cost, and (3) a conceptual design establishing feasibility at the selected approach. Energy consumption for the selected system was .034 1/km (61.3 mpg) for the heat engine and .221 kWh/km (.356 kWh/mi) for the electric power system over a modified J227 a schedule D driving cycle. Life cycle costs were 7.13 cents/km (11.5 cents/mi) at $2/gal gasoline and 7 cents/kWh electricity for 160,000 km (100,000 mi) life.

  20. A Dynamical Simulation Facility for Hybrid Systems

    CERN Document Server

    Back, A; Myers, M; Back, Allen; Guckenheimer, John; Myers, Mark

    1993-01-01

    Abstract: This paper establishes a general framework for describing hybrid dynamical systems which is particularly suitable for numerical simulation. In this context, the data structures used to describe the sets and functions which comprise the dynamical system are crucial since they provide the link between a natural mathematical formulation of a problem and the correct application of standard numerical algorithms. We describe a partial implementation of the design methodology and use this simulation tool for a specific control problem in robotics as an illustration of the utility of the approach for practical applications.

  1. Hybrid electric vehicle power management system

    Energy Technology Data Exchange (ETDEWEB)

    Bissontz, Jay E.

    2015-08-25

    Level voltage levels/states of charge are maintained among a plurality of high voltage DC electrical storage devices/traction battery packs that are arrayed in series to support operation of a hybrid electric vehicle drive train. Each high voltage DC electrical storage device supports a high voltage power bus, to which at least one controllable load is connected, and at least a first lower voltage level electrical distribution system. The rate of power transfer from the high voltage DC electrical storage devices to the at least first lower voltage electrical distribution system is controlled by DC-DC converters.

  2. Optimizing Dialogue Management with Reinforcement Learning: Experiments with the NJFun System

    CERN Document Server

    Kearns, M; Singh, S; Walker, M; 10.1613/jair.859

    2011-01-01

    Designing the dialogue policy of a spoken dialogue system involves many nontrivial choices. This paper presents a reinforcement learning approach for automatically optimizing a dialogue policy, which addresses the technical challenges in applying reinforcement learning to a working dialogue system with human users. We report on the design, construction and empirical evaluation of NJFun, an experimental spoken dialogue system that provides users with access to information about fun things to do in New Jersey. Our results show that by optimizing its performance via reinforcement learning, NJFun measurably improves system performance.

  3. Hybrid systems, optimal control and hybrid vehicles theory, methods and applications

    CERN Document Server

    Böhme, Thomas J

    2017-01-01

    This book assembles new methods showing the automotive engineer for the first time how hybrid vehicle configurations can be modeled as systems with discrete and continuous controls. These hybrid systems describe naturally and compactly the networks of embedded systems which use elements such as integrators, hysteresis, state-machines and logical rules to describe the evolution of continuous and discrete dynamics and arise inevitably when modeling hybrid electric vehicles. They can throw light on systems which may otherwise be too complex or recondite. Hybrid Systems, Optimal Control and Hybrid Vehicles shows the reader how to formulate and solve control problems which satisfy multiple objectives which may be arbitrary and complex with contradictory influences on fuel consumption, emissions and drivability. The text introduces industrial engineers, postgraduates and researchers to the theory of hybrid optimal control problems. A series of novel algorithmic developments provides tools for solving engineering pr...

  4. Research of IDSS Architecture Based on Hybrid Systems

    Institute of Scientific and Technical Information of China (English)

    MA Biao; YANG Bao-an

    2005-01-01

    This paper discusses the necessity of building IDSS on hybrid systems, and adopts XML technology to manage isomeric knowledge in hybrid systems. The paper proposes a new architecture of hybrid systems based IDSS whose core system is isomeric knowledge system. The architecture is composed of knowledge component, problems processing system, data component and intelligent user interface. This new architecture aims to enhance the capability of integrating hybrid systems, to improve the supporting effectiveness of decision-making and the intelligent level of IDSS, and tries a new way to elevate the system's ability of handling and learning knowledge.

  5. Interlaminar Fracture toughness in Glass-Cellulose Reinforced Epoxy hybrid composites

    Science.gov (United States)

    Uppin, Vinayak S.; Ashok; AnanthJoshi; Sridhar, I.; Shivakumar Gouda, P. S.

    2016-09-01

    Laminates of fibre reinforced compositesare weak in through thicknessbut strong in fibre direction, this lead to development of hybridizationconcept in polymer composites. In this work a new method of disperssing cellulose micro particleson unidirectional (UD) Glass fibre epoxy composite using semi-automated draw down coating technique was adopted to enhance fracture toughness.Test results show that by adding cellulose increases the load carrying competency by 32% in mode-I as compare to Glass- Epoxy composite samples. Imrovement in interlaminar critical energy release rates (GiC and GnC) up to 55% in Mode -I and 19 %in Mode -II respectively was also observed. This enahancement in fracture toughnees is due to the amount of fiber bridging seen during crack initiation and propagation.

  6. Corrosion and wear behaviour of Al–Mg–Si alloy matrix hybrid composites reinforced with rice husk ash and silicon carbide

    OpenAIRE

    Kenneth Kanayo Alaneme; Tolulope Moyosore Adewale; Peter Apata Olubambi

    2014-01-01

    The corrosion and wear behaviour of Al–Mg–Si alloy matrix hybrid composites developed with the use of rice husk ash (RHA) and silicon carbide (SiC) particulates as reinforcements were investigated. RHA and SiC mixed in weight ratios 0:1, 1:3, 1:1, 3:1, and 1:0 were utilized to prepare 5, 7.5 and 10 wt% of the reinforcing phase with Al Mg Si alloy as matrix using double stir casting process. Open circuit corrosion potential (OCP) and potentiodynamic polarization measurements were used to study...

  7. Poly(ε-caprolactone) reinforced with sol-gel synthesized organic-inorganic hybrid fillers as composite substrates for tissue engineering.

    Science.gov (United States)

    Russo, Teresa; Gloria, Antonio; D-Antò, Vincenzo; D'Amora, Ugo; Ametrano, Gianluca; Bollino, Flavia; De Santis, Roberto; Ausanio, Giovanni; Catauro, Michelina; Rengo, Sandro; Ambrosio, Luigi

    2010-01-01

    The importance of polymer-based composite materials to make multifunctional substrates for tissue engineering and the strategies to improve their performances have been stressed in the literature. Bioactive features of sol-gel synthesized poly(ε-caprolactone)/TiO₂ or poly(ε-caprolactone)/ZrO₂ organic-inorganic hybrid materials are widely documented. Accordingly, the aim of this preliminary research was to develop advanced composite substrates consisting of a poly(ε-caprolactone) matrix reinforced with sol-gel synthesized PCL/TiO₂ or PCL/ZrO₂ hybrid fillers. Micro-computed tomography and atomic force microscopy analyses allowed to study surface topography and roughness. On the other hand, mechanical and biological performances were evaluated by small punch tests and Alamar Blue™ assay, respectively. Micro-computed tomography and atomic force microscopy analyses highlighted the effect of the preparation technique. Results from small punch tests and Alamar Blue™ assay evidenced that PCL reinforced with Ti2 (PCL=12, TiO₂=88 wt%) and Zr2 (PCL=12, ZrO₂=88 wt%) hybrid fillers provided better mechanical and biological performances. PCL reinforced with Ti2 (PCL=12, TiO₂=88 wt%) and Zr2 (PCL=12, ZrO₂=88 wt%) hybrid fillers could be considered as advanced composite substrates for hard tissue engineering.

  8. Utilization of hybrid systems in Cuba

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Mercedes Menendez; Figueredo, Conrado Moreno [Renewable Energy Technologies Study Center (CETER), Marianao (Cuba)

    1996-12-31

    This work deals with the possibility of the wind-photovoltaic hybrid system uses for the electricity generation in Cuba. A design of energy installation is made to satisfy the tourism facilities demands located in Cayo Sabinal, in the north of the province Camaguey. The design is based on the data base of the available wind and solar resources. A group of existing wind-generators in the market is analyzed and the best is selected taking into account a set of energy parameters, the monthly energy supply is function of the turbines numbers and the quantity of necessary solar energy to guarantee the system requirements. An economical evaluation is carried out in order to select the best wind-solar combination and a comparison with other forms of electricity generation (Diesel Plant and a stand alone wind system). In the work is showed the best combination in the critical month is when a 62% of energy is supplied by wind energy and 38% of solar energy. Otherwise in the work is showed hybrid system is more economical than a stand alone wind system and a Diesel Plant. (Author)

  9. Dissipative dynamics of superconducting hybrid qubit systems

    Energy Technology Data Exchange (ETDEWEB)

    Montes, Enrique; Calero, Jesus M; Reina, John H, E-mail: enriquem@univalle.edu.c, E-mail: j.reina-estupinan@physics.ox.ac.u [Departamento de Fisica, Universidad del Valle, A.A. 25360, Cali (Colombia)

    2009-05-01

    We perform a theoretical study of composed superconducting qubit systems for the case of a coupled qubit configuration based on a hybrid qubit circuit made of both charge and phase qubits, which are coupled via a sigma{sub x} x sigma{sub z} interaction. We compute the system's eigen-energies in terms of the qubit transition frequencies and the strength of the inter-qubit coupling, and describe the sensitivity of the energy crossing/anti-crossing features to such coupling. We compute the hybrid system's dissipative dynamics for the cases of i) collective and ii) independent decoherence, whereby the system interacts with one common and two different baths of harmonic oscillators, respectively. The calculations have been performed within the Bloch-Redfield formalism and we report the solutions for the populations and the coherences of the system's reduced density matrix. The dephasing and relaxation rates are explicitly calculated as a function of the heat bath temperature.

  10. Modelling supervisory controller for hybrid power systems

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, A.; Bindner, H.; Lundsager, P. [Risoe National Lab., Roskilde (Denmark); Jannerup, O. [Technical Univ. of Denmark, Dept. of Automation, Lyngby (Denmark)

    1999-03-01

    Supervisory controllers are important to achieve optimal operation of hybrid power systems. The performance and economics of such systems depend mainly on the control strategy for switching on/off components. The modular concept described in this paper is an attempt to design standard supervisory controllers that could be used in different applications, such as village power and telecommunication applications. This paper presents some basic aspects of modelling and design of modular supervisory controllers using the object-oriented modelling technique. The functional abstraction hierarchy technique is used to formulate the control requirements and identify the functions of the control system. The modular algorithm is generic and flexible enough to be used with any system configuration and several goals (different applications). The modularity includes accepting modification of system configuration and goals during operation with minor or no changes in the supervisory controller. (au)

  11. Hybrid holographic non-destructive test system

    Science.gov (United States)

    Kurtz, R. L. (Inventor)

    1978-01-01

    An automatic hybrid holographic non-destructive testing (HNDT) method and system capable of detecting flaws or debonds contained within certain materials are described. This system incorporates the techniques of optical holography, acoustical/optical holography and holographic correlation in determining the structural integrity of a test object. An automatic processing system including a detector and automatic data processor is used in conjunction with the three holographic techniques for correlating and interpreting the information supplied by the non-destructive systems. The automatic system also includes a sensor which directly translates an optical data format produced by the holographic techniques into electrical signals and then transmits this information to a digital computer for indicating the structural properties of the test object. The computer interprets the data gathered and determines whether further testing is necessary as well as the format of this new testing procedure.

  12. Hybrid polymer composites reinforced by layered silicate and laser synthesized nanocarbons

    Science.gov (United States)

    Dinca, I.; Stefan, A.; Serghie, C.; Moga, A.; Dumitrache, L.; Vuluga, Z.; Donescu, D.; Dragomirescu, A.; Prodan, G.; Ciupina, V.; Gavrila-Florescu, L.; Popovici, E.; Sandu, I.

    2007-12-01

    The work presents some preliminary results obtained in the attempt to perform hybrid polymer-based nanocomposites with laser synthesized carbon nanostructures and layered silicate. The preliminary results suggest that there is a close relation between the improved characteristics of the obtained nanocomposite and filler's properties. Laser synthesized nanocarbons, from almost amorphous up to fullerenic-like structure were used. As layered silicate, a modified Cloisite-type montmorillonite is mentioned. Preliminary results suggest that some of these addition agents lead to samples of nanocomposites with significant improvement of their aimed properties.

  13. Neural systems underlying aversive conditioning in humans with primary and secondary reinforcers

    Directory of Open Access Journals (Sweden)

    Mauricio R Delgado

    2011-05-01

    Full Text Available Money is a secondary reinforcer commonly used across a range of disciplines in experimental paradigms investigating reward learning and decision-making. The effectiveness of monetary reinforcers during aversive learning and its neural basis, however, remains a topic of debate. Specifically, it is unclear if the initial acquisition of aversive representations of monetary losses depends on similar neural systems as more traditional aversive conditioning that involves primary reinforcers. This study contrasts the efficacy of a biologically defined primary reinforcer (shock and a socially defined secondary reinforcer (money during aversive learning and its associated neural circuitry. During a two-part experiment, participants first played a gambling game where wins and losses were based on performance to gain an experimental bank. Participants were then exposed to two separate aversive conditioning sessions. In one session, a primary reinforcer (mild shock served as an unconditioned stimulus (US and was paired with one of two colored squares, the conditioned stimuli (CS+ and CS-, respectively. In another session, a secondary reinforcer (loss of money served as the US and was paired with one of two different CS. Skin conductance responses were greater for CS+ compared to CS- trials irrespective of type of reinforcer. Neuroimaging results revealed that the striatum, a region typically linked with reward-related processing, was found to be involved in the acquisition of aversive conditioned response irrespective of reinforcer type. In contrast, the amygdala was involved during aversive conditioning with primary reinforcers, as suggested by both an exploratory fMRI analysis and a follow-up case study with a patient with bilateral amygdala damage. Taken together, these results suggest that learning about potential monetary losses may depend on reinforcement learning related systems, rather than on typical structures involved in more biologically based

  14. Bimode uninterruptible power supply compatibility in renewable hybrid energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Bower, W. (Sandia National Labs., Albuquerque, NM (USA)); O' Sullivan, G. (Abacus Controls, Inc., Somerville, NJ (USA))

    1990-08-01

    Inverters installed in renewable hybrid energy systems are typically used in a stand-alone mode to supply ac power to loads from battery storage when the engine-generator is not being used. Similarities in topology and in the performance requirements of the standby uninterruptible power supply (UPS) system and the hybrid system suggest the UPS could be used in hybrid energy systems. Another alternative to inverters with add-on charging circuits or standby UPS hardware is the Bimode UPS. The bimode UPS uses common circuitry and power components for dc to ac inversion and battery charging. It also provides an automatic and nearly instantaneous ac power transfer function when the engine-generator is started or stopped. The measured operating and transfer characteristics of a bimode UPS in a utility system and in a hybrid system are presented. The applicability of the bimode UPS to hybrid systems and its compatibility in a PV/engine-generator hybrid system are given.

  15. Optimization of Renewable Energy Hybrid System for Grid Connected Application

    Directory of Open Access Journals (Sweden)

    Mustaqimah Mustaqimah

    2012-10-01

    Full Text Available ABSTRACT. Hybrid energy systems are pollution free, takes low cost and less gestation period, user and social friendly. Such systems are important sources of energy for shops, schools, and clinics in village communities especially in remote areas. Hybrid systems can provide electricity at a comparatively economic price in many remote areas. This paper presents a method to jointly determine the sizing and operation control of hybrid energy systems. The model, PV wind hydro and biomass hybrid system connects to grid. The system configuration of the hybrid is derived based on a theoretical domestic load at a typical location and local solar radiation, wind and water flow rate data and biomass availability. The hybrid energy system is proposed for 10 of teacher’s houses of Industrial Training Institute, Mersing. It is predicted 10 kW load consumption per house. The hybrid energy system consists of wind, solar, biomass, hydro, and grid power. Approximately energy consumption is 860 kWh/day with a 105 kW peak demand load. The proposed hybrid renewable consists of solar photovoltaic (PV panels, wind turbine, hydro turbine and biomass. Battery and inverter are included as part of back-up and storage system. It provides the economic sensitivity of hybridization and the economic and environmental benefits of using a blend of technologies. It also presents the trade off that is involved in optimizing a hybrid energy system to harness and utilize the available renewable energy resources efficiently.

  16. Hybrid quantum systems of atoms and ions

    CERN Document Server

    Zipkes, Christoph; Palzer, Stefan; Sias, Carlo; Köhl, Michael

    2010-01-01

    In recent years, ultracold atoms have emerged as an exceptionally controllable experimental system to investigate fundamental physics, ranging from quantum information science to simulations of condensed matter models. Here we go one step further and explore how cold atoms can be combined with other quantum systems to create new quantum hybrids with tailored properties. Coupling atomic quantum many-body states to an independently controllable single-particle gives access to a wealth of novel physics and to completely new detection and manipulation techniques. We report on recent experiments in which we have for the first time deterministically placed a single ion into an atomic Bose Einstein condensate. A trapped ion, which currently constitutes the most pristine single particle quantum system, can be observed and manipulated at the single particle level. In this single-particle/many-body composite quantum system we show sympathetic cooling of the ion and observe chemical reactions of single particles in situ...

  17. Hybrid quantum systems of atoms and ions

    Energy Technology Data Exchange (ETDEWEB)

    Zipkes, Christoph; Ratschbacher, Lothar; Palzer, Stefan; Sias, Carlo; Koehl, Michael [Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom)

    2011-01-10

    In recent years, ultracold atoms have emerged as an exceptionally controllable experimental system to investigate fundamental physics, ranging from quantum information science to simulations of condensed matter models. Here we go one step further and explore how cold atoms can be combined with other quantum systems to create new quantum hybrids with tailored properties. Coupling atomic quantum many-body states to an independently controllable single-particle gives access to a wealth of novel physics and to completely new detection and manipulation techniques. We report on recent experiments in which we have for the first time deterministically placed a single ion into an atomic Bose Einstein condensate. A trapped ion, which currently constitutes the most pristine single particle quantum system, can be observed and manipulated at the single particle level. In this single-particle/many-body composite quantum system we show sympathetic cooling of the ion and observe chemical reactions of single particles in situ.

  18. Hybrid high power femtosecond laser system

    Science.gov (United States)

    Trunov, V. I.; Petrov, V. V.; Pestryakov, E. V.; Kirpichnikov, A. V.

    2006-01-01

    Design of a high-power femtosecond laser system based on hybrid chirped pulse amplification (CPA) technique developed by us is presented. The goal of the hybrid principle is the use of the parametric and laser amplification methods in chirped pulse amplifiers. It makes it possible to amplify the low-cycle pulses with a duration of <= fs to terawatt power with a high contrast and high conversion efficiency of the pump radiation. In a created system the Ti:Sapphire laser with 10 fs pulses at 810 nm and output energy about 1-3 nJ will be used like seed source. The oscillator pulses were stretched to duration of about 500 ps by an all-reflective grating stretcher. Then the stretched pulses are injected into a nondegenerate noncollinear optical parametric amplifier (NOPA) on the two BBO crystals. After amplification in NOPA the residual pump was used in a bow-tie four pass amplifier with hybrid active medium (based on Al II0 3:Ti 3+ and BeAl IIO 4:Ti 3+ crystals). The final stage of the amplification system consists of two channels, namely NIR (820 nm) and short-VIS (410 nm). Numerical simulation has shown that the terawatt level of output power can be achieved also in a short-VIS channel at the pumping of the double-crystal BBO NOPA by the radiation of the fourth harmonic of the Nd:YAG laser at 266 nm. Experimentally parametric amplification in BBO crystals of 30-50 fs pulses were investigated and optimized using SPIDER technique and single-shot autocomelator for the realization of shortest duration 40 fs.

  19. Spontaneously Igniting Hybrid Fuel-Oxidiser Systems

    Directory of Open Access Journals (Sweden)

    S. R. Jain

    1995-01-01

    Full Text Available After briefly outlining the recent developments in hybrid rockets, the work carried out by the author on self-igniting (hypergolic solid fuel-liquid oxidiser systems has been reviewed. A major aspect relates to the solid derivatives of hydrazines, which have been conceived as fuels for hybrid rockets. Many of these N-N bonded compounds ignite readily, with very short ignition delays, on coming into contact with liquid oxidisers, like HNO/sub 3/ and N/sub 2/ O/sub 4/. The ignition characteristics have been examined as a function of the nature of the functional group in the fuel molecule, in an attempt to establish a basis for the hypergolic ignition in terms of chemical reactivity of the fuel-oxidiser combination. Important chemical reactions occurring in the pre-ignition stage have been identified by examining the quenched reaction products. Hybrid systems exhibiting synergistic hypergolicity in the presence of metal powders have investigated. An estimation of the rocket performance parameters, experimental determination of the heats of combustion in HNO/sub 3/, thermal decomposition characteristics, temperature profile by thin film thermometry and product identification by the rapid scan FT-IR, are among the other relevant studies made on these systems. A significant recent development has been the synthesis of new N-N bonded viscous binders, capable of rataining the hypergolicity of the fuel powders embedded therein as well as providing the required mechanical strength to the grain. Several of these resins have been characterised. Metallised fuel composites of these resins having high loading of magnesium are found to have short ignition delays and high performance parameters.

  20. Superconducting qubit-resonator-atom hybrid system

    Science.gov (United States)

    Yu, Deshui; Kwek, Leong Chuan; Amico, Luigi; Dumke, Rainer

    2017-09-01

    We propose a hybrid quantum system where an LC resonator inductively interacts with a flux qubit and is capacitively coupled to a Rydberg atom. Varying the external magnetic flux bias controls the flux qubit flipping and the flux qubit-resonator interface. The atomic spectrum is tuned via an electrostatic field, manipulating the qubit-state transition of atom and the atom-resonator coupling. Different types of entanglement of superconducting, photonic and atomic qubits can be prepared via simply tuning the flux bias and electrostatic field, leading to the implementation of three-qubit Toffoli logic gate.

  1. THE USE OF GENETIC ALGORITHM IN DIMENSIONING HYBRID AUTONOMOUS SYSTEMS

    Directory of Open Access Journals (Sweden)

    RUS T.

    2016-03-01

    Full Text Available In this paper is presented the working principle of genetic algorithms used to dimension autonomous hybrid systems. It is presented a study case in which is dimensioned and optimized an autonomous hybrid system for a residential house located in Cluj-Napoca. After the autonomous hybrid system optimization is performed, it is achieved a reduction of the total cost of system investment, a reduction of energy produced in excess and a reduction of CO2 emissions.

  2. Hybrid Dislocated Control and General Hybrid Projective Dislocated Synchronization for Memristor Chaotic Oscillator System

    Directory of Open Access Journals (Sweden)

    Junwei Sun

    2014-01-01

    Full Text Available Some important dynamical properties of the memristor chaotic oscillator system have been studied in the paper. A novel hybrid dislocated control method and a general hybrid projective dislocated synchronization scheme have been realized for memristor chaotic oscillator system. The paper firstly presents hybrid dislocated control method for stabilizing chaos to the unstable equilibrium point. Based on the Lyapunov stability theorem, general hybrid projective dislocated synchronization has been studied for the drive memristor chaotic oscillator system and the same response memristor chaotic oscillator system. For the different dimensions, the memristor chaotic oscillator system and the other chaotic system have realized general hybrid projective dislocated synchronization. Numerical simulations are given to show the effectiveness of these methods.

  3. Hybrid composite laminates reinforced with Kevlar/carbon/glass woven fabrics for ballistic impact testing.

    Science.gov (United States)

    Randjbaran, Elias; Zahari, Rizal; Jalil, Nawal Aswan Abdul; Majid, Dayang Laila Abang Abdul

    2014-01-01

    Current study reported a facile method to investigate the effects of stacking sequence layers of hybrid composite materials on ballistic energy absorption by running the ballistic test at the high velocity ballistic impact conditions. The velocity and absorbed energy were accordingly calculated as well. The specimens were fabricated from Kevlar, carbon, and glass woven fabrics and resin and were experimentally investigated under impact conditions. All the specimens possessed equal mass, shape, and density; nevertheless, the layers were ordered in different stacking sequence. After running the ballistic test at the same conditions, the final velocities of the cylindrical AISI 4340 Steel pellet showed how much energy was absorbed by the samples. The energy absorption of each sample through the ballistic impact was calculated; accordingly, the proper ballistic impact resistance materials could be found by conducting the test. This paper can be further studied in order to characterise the material properties for the different layers.

  4. Hybrid Composite Laminates Reinforced with Kevlar/Carbon/Glass Woven Fabrics for Ballistic Impact Testing

    Directory of Open Access Journals (Sweden)

    Elias Randjbaran

    2014-01-01

    Full Text Available Current study reported a facile method to investigate the effects of stacking sequence layers of hybrid composite materials on ballistic energy absorption by running the ballistic test at the high velocity ballistic impact conditions. The velocity and absorbed energy were accordingly calculated as well. The specimens were fabricated from Kevlar, carbon, and glass woven fabrics and resin and were experimentally investigated under impact conditions. All the specimens possessed equal mass, shape, and density; nevertheless, the layers were ordered in different stacking sequence. After running the ballistic test at the same conditions, the final velocities of the cylindrical AISI 4340 Steel pellet showed how much energy was absorbed by the samples. The energy absorption of each sample through the ballistic impact was calculated; accordingly, the proper ballistic impact resistance materials could be found by conducting the test. This paper can be further studied in order to characterise the material properties for the different layers.

  5. Strontium-rich injectable hybrid system for bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Neves, Nuno, E-mail: nsmneves@gmail.com [Instituto de Investigação e Inovação em Saúde, Universidade do Porto (Portugal); INEB — Instituto de Engenharia Biomédica, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto (Portugal); FMUP — Faculdade de Medicina da Universidade do Porto, Departamento de Cirurgia, Serviço de Ortopedia, Alameda Prof. Hernâni Monteiro, 4200-319 Porto (Portugal); Campos, Bruno B. [FCUP — Faculdade de Ciências da Universidade do Porto, Centro de Investigação em Química, Departamento de Química e Bioquímica, Rua do Campo Alegre 1021/1055, 4169-007 Porto (Portugal); Almeida, Isabel F.; Costa, Paulo C. [FFUP — Faculdade de Farmácia da Universidade do Porto, Laboratório de Tecnologia Farmacêutica, Departamento de Ciências do Medicamento, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto (Portugal); Cabral, Abel Trigo [FMUP — Faculdade de Medicina da Universidade do Porto, Departamento de Cirurgia, Serviço de Ortopedia, Alameda Prof. Hernâni Monteiro, 4200-319 Porto (Portugal); and others

    2016-02-01

    Current challenges in the development of scaffolds for bone regeneration include the engineering of materials that can withstand normal dynamic physiological mechanical stresses exerted on the bone and provide a matrix capable of supporting cell migration and tissue ingrowth. The objective of the present work was to develop and characterize a hybrid polymer–ceramic injectable system that consists of an alginate matrix crosslinked in situ in the presence of strontium (Sr), incorporating a ceramic reinforcement in the form of Sr-rich microspheres. The incorporation of Sr in the microspheres and in the vehicle relies on the growing evidence that Sr has beneficial effects in bone remodeling and in the treatment of osteopenic disorders and osteoporosis. Sr-rich porous hydroxyapatite microspheres with a uniform size and a mean diameter of 555 μm were prepared, and their compression strength and friability tested. A 3.5% (w/v) ultrapure sodium alginate solution was used as the vehicle and its in situ gelation was promoted by the addition of calcium (Ca) or Sr carbonate and Glucone-δ-lactone. Gelation times varied with temperature and crosslinking agent, being slower for Sr than for Ca, but adequate for injection in both cases. Injectability was evaluated using a device employed in vertebroplasty surgical procedures, coupled to a texture analyzer in compression mode. Compositions with 35% w of microspheres presented the best compromise between injectability and compression strength of the system, the force required to extrude it being lower than 100 N. Micro CT analysis revealed a homogeneous distribution of the microspheres inside the vehicle, and a mean inter-microspheres space of 220 μm. DMA results showed that elastic behavior of the hybrid is dominant over the viscous one and that the higher storage modulus was obtained for the 3.5%Alg–35%Sr-HAp-Sr formulation. - Highlights: • We developed a Sr rich viscoelastic hybrid system (alginate matrix crosslinked in

  6. Nuclear Hybrid Energy Systems: Challenges and Opportunities

    Energy Technology Data Exchange (ETDEWEB)

    P. Sabharwall; S.B. Sitton; S.J. Yoon; C. Stoots

    2014-07-01

    With growing demand of energy and costs of the fossil fuels, coupled with the environmental concerns have resulted in an increased interest in alternative energy sources. Nuclear hybrid energy systems (NHES) are being considered which incorporates renewable energy sources such as solar and wind energy combined with nuclear reactor and energy storage to meet the peak hours demand imposed on the grid, along with providing process heat for other potential industrial applications. This concept could potentially satisfy various energy demands and improve reliability, robustness and resilience for the entire system as a whole, along with economic and net efficiency gains. This paper provides a brief understanding of potential NHES system and architecture along with the challenges

  7. Experiments on Hybrid Precast Concrete Shear Walls Emulating Monolithic Construction with Different Amounts of Posttensioned Strands and Different Debond Lengths of Grouted Reinforcements

    Directory of Open Access Journals (Sweden)

    Zhangfeng Zhu

    2016-01-01

    Full Text Available This paper proposed a hybrid precast concrete shear wall emulating monolithic construction (HPWEM that utilized grouted vertical connecting reinforcements and unbonded posttensioned high-strength strands across the horizontal joint for the lateral resistance. The grouted reinforcements with predetermined debond length were used to provide strength by tension and energy dissipation by yielding. The posttensioned strands were mainly employed to offer the restoring force to reduce the residual displacement by elastic extension. The overlapping welded closed stirrups improved the confinement property of the restrained concrete, avoiding the brittle failure. Six HPWEM specimens, considering variables including the amounts of strands and the debond lengths of grouted reinforcements, as well as one referenced cast-in-place monolithic wall specimen, were tested under the low-cycle reversed lateral load. The HPWEM specimens were capable of providing strength, stiffness, ductility, and energy dissipation equivalent to that of the monolithic wall specimen under certain variable condition.

  8. Corrosion and wear behaviour of Al–Mg–Si alloy matrix hybrid composites reinforced with rice husk ash and silicon carbide

    Directory of Open Access Journals (Sweden)

    Kenneth Kanayo Alaneme

    2014-01-01

    Full Text Available The corrosion and wear behaviour of Al–Mg–Si alloy matrix hybrid composites developed with the use of rice husk ash (RHA and silicon carbide (SiC particulates as reinforcements were investigated. RHA and SiC mixed in weight ratios 0:1, 1:3, 1:1, 3:1, and 1:0 were utilized to prepare 5, 7.5 and 10 wt% of the reinforcing phase with Al Mg Si alloy as matrix using double stir casting process. Open circuit corrosion potential (OCP and potentiodynamic polarization measurements were used to study the corrosion behaviour while coefficient of friction was used to assess the wear behaviour of the composites. The corrosion and wear mechanisms were established with the aid of scanning electron microscopy. The results show that the effect of RHA/SiC weight ratio on the corrosion behaviour of the composites in 3.5% NaCl solution was not consistent for the different weight percent of reinforcement (5, 7.5, and 10 wt% used in developing the Al–Mg–Si based composites. It was evident that for most cases the use of hybrid reinforcement of RHA and SiC resulted in improved corrosion resistance of the composites in 3.5% NaCl solution. Preferential dissolution of the more anodic Al–Mg–Si alloy matrix around the Al–Mg–Si matrix/RHA/SiC particle interfaces was identified as the primary corrosion mechanism. The coefficient of friction and consequently the wear resistance of the hybrid composites were comparable to that of the Al–Mg–Si alloy matrix reinforced with only SiC.

  9. The Measurement and Functional Properties of Reinforcer Value in Single-Alternative Responding: A Test of Linear System Theory

    Science.gov (United States)

    Dallery, Jesse; McDowell, J. J.; Soto, Paul L.

    2004-01-01

    Matching theory and linear system theory make different predictions about how the y-asymptote, k, of Herrnstein's (1970) hyperbola varies with reinforcer value. The present experiment tested both these predictions and linear system theory's account of how reinforcement rate and reinforcer value jointly govern response rate. Eight rats served as…

  10. Traffic Light Control by Multiagent Reinforcement Learning Systems

    NARCIS (Netherlands)

    Bakker, B.; Whiteson, S.; Kester, L.J.H.M.; Groen, F.C.A.

    2010-01-01

    Traffic light control is one of the main means of controlling road traffic. Improving traffic control is important because it can lead to higher traffic throughput and reduced traffic congestion. This chapter describes multiagent reinforcement learning techniques for automatic optimization of

  11. Flame Retardancy Effects of Graphene Nanoplatelet/Carbon Nanotube Hybrid Membranes on Carbon Fiber Reinforced Epoxy Composites

    Directory of Open Access Journals (Sweden)

    Dongxian Zhuo

    2013-01-01

    Full Text Available Carbon nanotube/graphene nanoplatelet (MWCNT/GNP hybrid membranes with lower liquid permeability and better barrier effect compared to MWCNT membranes were successfully synthesized by vacuum filtering. Their morphologies, water permeability, and pore structures were characterized by a scanning electron microscope (SEM and nitrogen adsorption isotherms. Furthermore, MWCNT/GNP membranes were used to improve the flame retardancy of carbon fiber reinforced polymer (CFRP composites, and the influence of weight percentage of GNPs on the permeability and flame retardancy of MWCNT/GNP membranes was systematically investigated. Results show that incorporation of MWCNT/GNP membranes on CFRP composite plates can remarkably improve the flame retardancy of CFRP composites. Specifically, the incorporation of hierarchical MWCNT/GNP membrane with 7.5 wt% of GNP displays a 35% reduction in the peak heat release rate (PHRR for a CFRP composite plate with the epoxy as matrix and a 11% reduction in PHRR compared with the incorporation of MWCNT membrane only. A synergistic flame retarding mechanism is suggested to be attributed to these results, which includes controlling the pore size and penetrative network structure.

  12. Novel Electrospun Polylactic Acid Nanocomposite Fiber Mats with Hybrid Graphene Oxide and Nanohydroxyapatite Reinforcements Having Enhanced Biocompatibility

    Directory of Open Access Journals (Sweden)

    Chen Liu

    2016-08-01

    Full Text Available Graphene oxide (GO and a nanohydroxyapatite rod (nHA of good biocompatibility were incorporated into polylactic acid (PLA through electrospinning to form nanocomposite fiber scaffolds for bone tissue engineering applications. The preparation, morphological, mechanical and thermal properties, as well as biocompatibility of electrospun PLA scaffolds reinforced with GO and/or nHA were investigated. Electron microscopic examination and image analysis showed that GO and nHA nanofillers refine the diameter of electrospun PLA fibers. Differential scanning calorimetric tests showed that nHA facilitates the crystallization process of PLA, thereby acting as a nucleating site for the PLA molecules. Tensile test results indicated that the tensile strength and elastic modulus of the electrospun PLA mat can be increased by adding 15 wt % nHA. The hybrid nanocomposite scaffold with 15 wt % nHA and 1 wt % GO fillers exhibited higher tensile strength amongst the specimens investigated. Furthermore, nHA and GO nanofillers enhanced the water uptake of PLA. Cell cultivation, 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT and alkaline phosphatase tests demonstrated that all of the nanocomposite scaffolds exhibit higher biocompatibility than the pure PLA mat, particularly for the scaffold with 15 wt % nHA and 1 wt % GO. Therefore, the novel electrospun PLA nanocomposite scaffold with 15 wt % nHA and 1 wt % GO possessing a high tensile strength and modulus, as well as excellent cell proliferation is a potential biomaterial for bone tissue engineering applications.

  13. Intelligent Control Scheme of Engineering Machinery of Cluster Hybrid System

    Institute of Scientific and Technical Information of China (English)

    GAO Qiang; WANG Hongli

    2005-01-01

    In a hybrid system, the subsystems with discrete dynamics play a central role in a hybrid system. In the course of engineering machinery of cluster construction, the discrete control law is hard to obtain because the construction environment is complex and there exist many affecting factors. In this paper, hierarchically intelligent control, expert control and fuzzy control are introduced into the discrete subsystems of engineering machinery of cluster hybrid system, so as to rebuild the hybrid system and make the discrete control law easily and effectively obtained. The structures, reasoning mechanism and arithmetic of intelligent control are replanted to discrete dynamic, conti-nuous process and the interface of the hybrid system. The structures of three types of intelligent hybrid system are presented and the human experiences summarized from engineering machinery of cluster are taken into account.

  14. Automation Comparison Procedure for Verification of Hybrid Systems.

    Science.gov (United States)

    1997-11-01

    Lecture Notes in Computer Science vol. 999, Springer-Verlag, (1995). [2] Bowler, 0., Grotzky, J., Nielson, M., Nilson.S., and Van Buren, J...Remmel, J.B., "Feedback Derivations: Near Optimal Controls for Hybrid Systems", to appear in Hybrid Systems III, Springer Lecture Notes in Computer Science . [6...Grossman, R.L., Nerode, A., Ravn, A. and Rischel, H. eds., Hybrid Systems, Lecture Notes in Computer

  15. Effect of Coconut Fillers on Hybrid Coconut Kevlar Fiber Reinforced Epoxy Composites

    Directory of Open Access Journals (Sweden)

    S. P. Jani

    2015-12-01

    Full Text Available This project focuses on the conversion of naturally available coconut fibers and shells into a useful composite. In addition to it, some mechanical properties of the resultant composite is determined and also the effect of coconut shell fillers on the composite is also investigated. The few portion of the composite is incorporated with synthetic Kevlar fiber, thus the coconut fiber is hybridized to enhance the mechanical properties of coconut. In this work two types of composite is fabricate, kevelar coconut fibre (kc composite and kevelarcoco nut fibre coconut shell filler (kccsf composite. Coconut fibers have low weight and considerable properties among the natural fibers, while coconut fillers have a good ductile and impact property. The natural fibers and fillers are treated with Na-OH to make it free of organic impurities. Epoxy resin is used as the polymer matrix. Two composite are produced one with fillers and the other without the fillers using compression molding method. Mechanical properties like tensile strength, flexural strength and water absorption tests are done with ASTM standard. It is observed that that the addition of filler materials improves the adhesiveness of the fibers leading to the increase in the above mentioned properties. The density of the composite is also low hence the strength to weight ratio is very high. The water absorption test also showed that the resultant composite had a small adhesion to water and absorption of water.

  16. CROWDED HYBRID PANEL MANUFACTURED WITH PEANUT HULLS REINFORCED WITH ITAÚBA WOOD PARTICLES

    Directory of Open Access Journals (Sweden)

    Guilherme Barbirato

    2014-09-01

    Full Text Available http://dx.doi.org/10.5902/1980509815726In this paper, it was considered the study of the potential use of peanut hulls and wood particles of itaúba (Mezilaurus itauba species in order to add value to these materials through the manufacture of hybrid particle board in order to compare the physical and mechanical performances as well as durability. For these procedures, it was used the bi-component polyurethane resin based on castor beans (mammon oil and urea-formaldehyde. The product quality was evaluated based on the requirements of the standards NBR 14.810:2006 APA PRP and 108, through physico-mechanical and microstructural durability. The results indicate that the incorporation of wood particles warrants an increase in physical-mechanical properties of the particleboard manufactured with peanut hulls, the polyurethane resin based on castor oil was effective as a particle adhesive binder and the durability assay indicated that the material should be used under conditions of low exposure to moisture.

  17. DISPATCHING OF HYBRID WINDPHOTOVOLTAIC- MICROTURBINESSTORAGE SYSTEM

    Directory of Open Access Journals (Sweden)

    Dr. BRINI SAOUSSEN

    2012-06-01

    Full Text Available This paper presents model for Economic Environmental Dispatching (EED of Hybrid power system including wind and photovoltaic energies. The model combines the stochastic data of the climate such as the wind speed for wind energy, solar radiation and the temperature for photovoltaic energy. The penetration of wind andphotovoltaic powers into traditional network will cause some implications such as security concerns due to its unpredictable nature. The production systems of renewable energy are generally coupled with the network with energy storage devices and micro sources. In this paper, a bi-objective economic environmental dispatchproblem considering wind and photovoltaic penetration is formulated, which treats economic and environmental impacts as conflicting objectives. It applied multiobjective optimization by approach SPEA to solve (EED problem.

  18. Infectious disease modeling a hybrid system approach

    CERN Document Server

    Liu, Xinzhi

    2017-01-01

    This volume presents infectious diseases modeled mathematically, taking seasonality and changes in population behavior into account, using a switched and hybrid systems framework. The scope of coverage includes background on mathematical epidemiology, including classical formulations and results; a motivation for seasonal effects and changes in population behavior, an investigation into term-time forced epidemic models with switching parameters, and a detailed account of several different control strategies. The main goal is to study these models theoretically and to establish conditions under which eradication or persistence of the disease is guaranteed. In doing so, the long-term behavior of the models is determined through mathematical techniques from switched systems theory. Numerical simulations are also given to augment and illustrate the theoretical results and to help study the efficacy of the control schemes.

  19. Development of Traction Drive Motors for the Toyota Hybrid System

    Science.gov (United States)

    Kamiya, Munehiro

    Toyota Motor Corporation developed in 2005 a new hybrid system for a large SUV. This system included the new development of a high-speed traction drive motor achieving a significant increase in power weight ratio. This paper provides an overview of the hybrid system, discusses the characteristics required of a traction drive motor, and presents the technologies employed in the developed motor.

  20. Geo synthetic-reinforced Pavement systems; Sistemas de pavimentos reforzados con geosinteticos

    Energy Technology Data Exchange (ETDEWEB)

    Zornberg, J. G.

    2014-02-01

    Geo synthetics have been used as reinforcement inclusions to improve pavement performance. while there are clear field evidence of the benefit of using geo synthetic reinforcements, the specific conditions or mechanisms that govern the reinforcement of pavements are, at best, unclear and have remained largely unmeasured. Significant research has been recently conducted with the objectives of: (i) determining the relevant properties of geo synthetics that contribute to the enhanced performance of pavement systems, (ii) developing appropriate analytical, laboratory and field methods capable of quantifying the pavement performance, and (iii) enabling the prediction of pavement performance as a function of the properties of the various types of geo synthetics. (Author)

  1. Limit Cycle Analysis in a Class of Hybrid Systems

    Directory of Open Access Journals (Sweden)

    Antonio Favela-Contreras

    2016-01-01

    Full Text Available Hybrid systems are those that inherently combine discrete and continuous dynamics. This paper considers the hybrid system model to be an extension of the discrete automata associating a continuous evolution with each discrete state. This model is called the hybrid automaton. In this work, we achieve a mathematical formulation of the steady state and we show a way to obtain the initial conditions region to reach a specific limit cycle for a class of uncoupled and coupled continuous-linear hybrid systems. The continuous-linear term is used in the sense of the system theory and, in this sense, continuous-linear hybrid automata will be defined. Thus, some properties and theorems that govern the hybrid automata dynamic behavior to evaluate a limit cycle existence have been established; this content is explained under a theoretical framework.

  2. On a Variational Approach to Optimization of Hybrid Mechanical Systems

    Directory of Open Access Journals (Sweden)

    Vadim Azhmyakov

    2010-01-01

    Full Text Available This paper deals with multiobjective optimization techniques for a class of hybrid optimal control problems in mechanical systems. We deal with general nonlinear hybrid control systems described by boundary-value problems associated with hybrid-type Euler-Lagrange or Hamilton equations. The variational structure of the corresponding solutions makes it possible to reduce the original “mechanical” problem to an auxiliary multiobjective programming reformulation. This approach motivates possible applications of theoretical and computational results from multiobjective optimization related to the original dynamical optimization problem. We consider first order optimality conditions for optimal control problems governed by hybrid mechanical systems and also discuss some conceptual algorithms.

  3. The Gwaii Haanas PV hybrid system : analysis of system operation

    Energy Technology Data Exchange (ETDEWEB)

    Ross, M. [GPCo Inc., Varennes, PQ (Canada); Turcotte, D.; Sheriff, F. [Natural Resources Canada, Varennes, PQ (Canada). CANMET Energy Technology Centre

    2003-05-01

    The operation of the photovoltaic/battery/genset hybrid power system at the Gwaii Haanas National Park Reserve warden station in British Columbia has been monitored since July 2001 as part of the Canada Centre for Mineral and Energy Technology (CANMET) Energy Technology Centre-Varennes Photovoltaic Hybrid Power Systems Program. The data collected has been used to validate hybrid system simulation tools being developed under the sponsorship of the Program. The analyzed data, along with the simulation tools, provided insight into the operation of the Gwaii Haanas power system. It also assisted in identifying the strengths and weaknesses of the system. Data indicates that the system functions well and is appropriately dimensioned and configured. The modules are arranged in two sub-arrays, with modules connected in parallel, showing remarkable tolerance to shading of part of the array. Almost complete discharge of the batteries occurs during the winter, when the Park residence is unoccupied. During the summer, users should keep track of the battery state-of-charge. Some recommendations were made to prolong the battery life. 1 ref., 1 tab., 16 figs.

  4. Effect of crosslinking functionality on microstructure, mechanical properties, and in vitro cytocompatibility of cellulose nanocrystals reinforced poly (vinyl alcohol)/sodium alginate hybrid scaffolds.

    Science.gov (United States)

    Kumar, Anuj; Lee, Yujin; Kim, Doyeon; Rao, Kummara Madhusudana; Kim, Jisoo; Park, Soyoung; Haider, Adnan; Lee, Do Hyun; Han, Sung Soo

    2017-02-01

    Cellulose nanocrystals reinforced poly (vinyl alcohol)/sodium alginate hybrid scaffolds were fabricated by using freeze casting and freeze drying method. In this study, the effect of crosslinking agents such as calcium chloride, orthophosphoric acid, and borax on morphological, structural, thermal, mechanical, and cytocompatibility (cell adhesion and proliferation) properties was investigated. The results showed that the change in type of crosslinking agent significantly changed the properties of the hybrid scaffolds. Based on this study, borax-crosslinked hybrid scaffold showed good fibrous porous structure with high porosity (95.2%), highest water uptake capacity, good thermal stability, mechanical stability (storage modulus), and in vitro cell adhesion and proliferation with fibroblast (NIH3T3) cells. This primarily research study explores the way for further use of this crosslinking agent to design and fabricate scaffolds for tissue engineering applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. The cerebellum: A neural system for the study of reinforcement learning

    Directory of Open Access Journals (Sweden)

    Rodney A. Swain

    2011-03-01

    Full Text Available In its strictest application, the term reinforcement learning refers to a computational approach to learning in which an agent (often a machine interacts with a mutable environment to maximize reward through trial and error. The approach borrows essentials from several fields, most notably Computer Science, Behavioral Neuroscience, and Psychology. At the most basic level, a neural system capable of mediating reinforcement learning must be able to acquire sensory information about the external environment and internal milieu (either directly or through connectivities with other brain regions, must be able to select a behavior to be executed, and must be capable of providing evaluative feedback about the success of that behavior. Given that Psychology informs us that reinforcers, both positive and negative, are stimuli or consequences that increase the probability that the immediately antecedent behavior will be repeated and that reinforcer strength or viability is modulated by the organism’s past experience with the reinforcer, its affect, and even the state of its muscles (e.g., eyes open or closed; it is the case that any neural system that supports reinforcement learning must also be sensitive to these same considerations. Once learning is established, such a neural system must finally be able to maintain continued response expression and prevent response drift. In this report, we examine both historical and recent evidence that the cerebellum satisfies all of these requirements. While we report evidence from a variety of learning paradigms, the majority of our discussion will focus on classical conditioning of the rabbit eye blink response as an ideal model system for the study of reinforcement and reinforcement learning.

  6. The cerebellum: a neural system for the study of reinforcement learning.

    Science.gov (United States)

    Swain, Rodney A; Kerr, Abigail L; Thompson, Richard F

    2011-01-01

    In its strictest application, the term "reinforcement learning" refers to a computational approach to learning in which an agent (often a machine) interacts with a mutable environment to maximize reward through trial and error. The approach borrows essentials from several fields, most notably Computer Science, Behavioral Neuroscience, and Psychology. At the most basic level, a neural system capable of mediating reinforcement learning must be able to acquire sensory information about the external environment and internal milieu (either directly or through connectivities with other brain regions), must be able to select a behavior to be executed, and must be capable of providing evaluative feedback about the success of that behavior. Given that Psychology informs us that reinforcers, both positive and negative, are stimuli or consequences that increase the probability that the immediately antecedent behavior will be repeated and that reinforcer strength or viability is modulated by the organism's past experience with the reinforcer, its affect, and even the state of its muscles (e.g., eyes open or closed); it is the case that any neural system that supports reinforcement learning must also be sensitive to these same considerations. Once learning is established, such a neural system must finally be able to maintain continued response expression and prevent response drift. In this report, we examine both historical and recent evidence that the cerebellum satisfies all of these requirements. While we report evidence from a variety of learning paradigms, the majority of our discussion will focus on classical conditioning of the rabbit eye blink response as an ideal model system for the study of reinforcement and reinforcement learning.

  7. Site characterization for hybrid system construction

    Energy Technology Data Exchange (ETDEWEB)

    Saldana, R.; Miranda, U.; Medrano, M. C. [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    The basic reason to use alternative systems for electricity generation, in most cases, is the lack of electricity services, such as isolated rural communities which are located far away from the electric distribution line, and the cost of its extension is too expensive, while decentralized power systems can be an economic and appropriate solution to providing these services. Up to now there are several technological options for rural electrification using PV modules, wind plants, water-power plants, anaerobic digesters, or a combination of some of them, according to the availability of energetic resources. The applications include centralized or decentralized systems, autonomous or hybrid systems, isolated or interconnected to the electric line, etc. A particular hybrid system design can be done considering two general aspects, first it is necessary to know the electric consumption that will be supplied, taking into account present and future necessities and how local energetic resources are present in a selected site. Finally, also it is necessary to carry out an economic analysis to determine the cost of kilowatt-hour generated using local energetic resources and compare it with the cost of electricity produced by conventional power systems. [Espanol] La razon principal para el uso de sistemas alternativos de generacion de electricidad, en la mayoria de los casos, es la falta de servicios de electricidad, tal como en las comunidades rurales aisladas localizadas lejos de linea de distribucion electrica, donde el costo de su extension es demasiado caro, mientras que los sistemas descentralizados de energia pueden ser una solucion economica y adecuada para proporcionar estos servicios. Hasta ahora existen varias opciones tecnologicas para la electrificacion rural usando modulos fotovoltaicos, aerogeneradores, plantas hidroelectricas, digestores anaerobicos o una combinacion de algunos de ellos, de acuerdo con la disponibilidad de los recursos energeticos. Las

  8. Parallel Hybrid Vehicle Optimal Storage System

    Science.gov (United States)

    Bloomfield, Aaron P.

    2009-01-01

    A paper reports the results of a Hybrid Diesel Vehicle Project focused on a parallel hybrid configuration suitable for diesel-powered, medium-sized, commercial vehicles commonly used for parcel delivery and shuttle buses, as the missions of these types of vehicles require frequent stops. During these stops, electric hybridization can effectively recover the vehicle's kinetic energy during the deceleration, store it onboard, and then use that energy to assist in the subsequent acceleration.

  9. A Future with Hybrid Electric Propulsion Systems: A NASA Perspective

    Science.gov (United States)

    DelRosario, Ruben

    2014-01-01

    The presentation highlights a NASA perspective on Hybrid Electric Propulsion Systems for aeronautical applications. Discussed are results from NASA Advance Concepts Study for Aircraft Entering service in 2030 and beyond and the potential use of hybrid electric propulsion systems as a potential solution to the requirements for energy efficiency and environmental compatibility. Current progress and notional potential NASA research plans are presented.

  10. HOPIS: hybrid omnidirectional and perspective imaging system for mobile robots.

    Science.gov (United States)

    Lin, Huei-Yung; Wang, Min-Liang

    2014-09-04

    In this paper, we present a framework for the hybrid omnidirectional and perspective robot vision system. Based on the hybrid imaging geometry, a generalized stereo approach is developed via the construction of virtual cameras. It is then used to rectify the hybrid image pair using the perspective projection model. The proposed method not only simplifies the computation of epipolar geometry for the hybrid imaging system, but also facilitates the stereo matching between the heterogeneous image formation. Experimental results for both the synthetic data and real scene images have demonstrated the feasibility of our approach.

  11. Design, analysis and modeling of a novel hybrid powertrain system based on hybridized automated manual transmission

    Science.gov (United States)

    Wu, Guang; Dong, Zuomin

    2017-09-01

    Hybrid electric vehicles are widely accepted as a promising short to mid-term technical solution due to noticeably improved efficiency and lower emissions at competitive costs. In recent years, various hybrid powertrain systems were proposed and implemented based on different types of conventional transmission. Power-split system, including Toyota Hybrid System and Ford Hybrid System, are well-known examples. However, their relatively low torque capacity, and the drive of alternative and more advanced designs encouraged other innovative hybrid system designs. In this work, a new type of hybrid powertrain system based hybridized automated manual transmission (HAMT) is proposed. By using the concept of torque gap filler (TGF), this new hybrid powertrain type has the potential to overcome issue of torque gap during gearshift. The HAMT design (patent pending) is described in details, from gear layout and design of gear ratios (EV mode and HEV mode) to torque paths at different gears. As an analytical tool, mutli-body model of vehicle equipped with this HAMT was built to analyze powertrain dynamics at various steady and transient modes. A gearshift was decomposed and analyzed based basic modes. Furthermore, a Simulink-SimDriveline hybrid vehicle model was built for the new transmission, driveline and vehicle modular. Control strategy has also been built to harmonically coordinate different powertrain components to realize TGF function. A vehicle launch simulation test has been completed under 30% of accelerator pedal position to reveal details during gearshift. Simulation results showed that this HAMT can eliminate most torque gap that has been persistent issue of traditional AMT, improving both drivability and performance. This work demonstrated a new type of transmission that features high torque capacity, high efficiency and improved drivability.

  12. Microstructural characteristics, mechanical and wear behaviour of aluminium matrix hybrid composites reinforced with alumina, rice husk ash and graphite

    Directory of Open Access Journals (Sweden)

    Kenneth Kanayo Alaneme

    2015-09-01

    Full Text Available The microstructural characteristics, mechanical and wear behaviour of Aluminium matrix hybrid composites reinforced with alumina, rice husk ash (RHA and graphite were investigated. Alumina, RHA and graphite mixed in varied weight ratios were utilized to prepare 10 wt% hybrid reinforced Al-Mg-Si alloy based composites using two-step stir casting. Hardness, tensile properties, scanning electron microscopy, and wear tests were used to characterize the composites produced. The results show that Hardness decreases with increase in the weight ratio of RHA and graphite in the composites; and with RHA content greater than 50%, the effect of graphite on the hardness becomes less significant. The tensile strength for the composites containing o.5wt% graphite and up to 50% RHA was observed to be higher than that of the composites without graphite. The toughness values for the composites containing 0.5wt% graphite were in all cases higher than that of the composites without graphite. The % Elongation for all composites produced was within the range of 10–13% and the values were invariant to the RHA and graphite content. The tensile fracture surface morphology in all the composites produced was identical characterized with the presence of reinforcing particles housed in ductile dimples. The composites without graphite exhibited greater wear susceptibility in comparison to the composite grades containing graphite. However the wear resistance decreased with increase in the graphite content from 0.5 to 1.5 wt%.

  13. Hybrid dislocated control and general hybrid projective dislocated synchronization for the modified Lue chaotic system

    Energy Technology Data Exchange (ETDEWEB)

    Xu Yuhua [College of Information Science and Technology, Donghua University, Shanghai 201620 (China) and Department of Maths, Yunyang Teacher' s College, Hubei 442000 (China)], E-mail: yuhuaxu2004@163.com; Zhou Wuneng [College of Information Science and Technology, Donghua University, Shanghai 201620 (China)], E-mail: wnzhou@163.com; Fang Jianan [College of Information Science and Technology, Donghua University, Shanghai 201620 (China)

    2009-11-15

    This paper introduces a modified Lue chaotic system, and some basic dynamical properties are studied. Based on these properties, we present hybrid dislocated control method for stabilizing chaos to unstable equilibrium and limit cycle. In addition, based on the Lyapunov stability theorem, general hybrid projective dislocated synchronization (GHPDS) is proposed, which includes complete dislocated synchronization, dislocated anti-synchronization and projective dislocated synchronization as its special item. The drive and response systems discussed in this paper can be strictly different dynamical systems (including different dimensional systems). As examples, the modified Lue chaotic system, Chen chaotic system and hyperchaotic Chen system are discussed. Numerical simulations are given to show the effectiveness of these methods.

  14. Filtering and control of stochastic jump hybrid systems

    CERN Document Server

    Yao, Xiuming; Zheng, Wei Xing

    2016-01-01

    This book presents recent research work on stochastic jump hybrid systems. Specifically, the considered stochastic jump hybrid systems include Markovian jump Ito stochastic systems, Markovian jump linear-parameter-varying (LPV) systems, Markovian jump singular systems, Markovian jump two-dimensional (2-D) systems, and Markovian jump repeated scalar nonlinear systems. Some sufficient conditions are first established respectively for the stability and performances of those kinds of stochastic jump hybrid systems in terms of solution of linear matrix inequalities (LMIs). Based on the derived analysis conditions, the filtering and control problems are addressed. The book presents up-to-date research developments and novel methodologies on stochastic jump hybrid systems. The contents can be divided into two parts: the first part is focused on robust filter design problem, while the second part is put the emphasis on robust control problem. These methodologies provide a framework for stability and performance analy...

  15. Nuclear Hybrid energy Systems: Molten Salt Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Green, M.; Sabharwall, P.; Yoon, S. J.; Bragg-Sitton, S. B.; Stoot, C.

    2014-07-01

    Without growing concerns in reliable energy supply, the next generation in reliable power generation via hybrid energy systems is being developed. A hybrid energy system incorporates multiple energy input source sand multiple energy outputs. The vitality and efficiency of these combined systems resides in the energy storage application. Energy storage is necessary for grid stabilization because stored excess energy is used later to meet peak energy demands. With high thermal energy production the primary nuclear heat generation source, molten salt energy storage is an intriguing option because of its distinct thermal properties. This paper discusses the criteria for efficient energy storage and molten salt energy storage system options for hybrid systems. (Author)

  16. Modeling and Analysis of Hybrid Dynamic Systems Using Hybrid Petri Nets

    OpenAIRE

    GHOMRI Latefa; Alla, Hassane

    2008-01-01

    Some extensions of PNs permitting HDS modeling were presented here. The first models to be presented are continuous PNs. This model may be used for modeling either a continuous system or a discrete system. In this case, it is an approximation that is often satisfactory. Hybrid PNs combine in the same formalism a discrete PN and a continuous PN. Two hybrid PN models were considered in this chapter. The first, called the hybrid PN, has a deterministic behavior; this means that we can predict th...

  17. Advantages of Hybrid Global Navigation Satellite Systems

    Directory of Open Access Journals (Sweden)

    Asim Bilajbegović

    2007-05-01

    Full Text Available In a decision-making situation, what kind of GPS equipment to purchase, one always has a dilemma, tobuy hybrid (GPS+GLONASS or only GPS receivers? In the case of completeness of the GLONASS satellite system, this dilemma probably would not have existed. The answer to this dilemma is given in the present paper, but for the constellation of the GLONASS satellites in summer 2006 (14 satellites operational. Due to the short operational period of these satellites (for example GLONASS-M, 5 years, and not launching new ones, at this moment (February 25, 2007, only 10 satellites are operational. For the sake of research and giving answers to these questions, about 252 RTK measurements have been done using (GPS and GNSS receivers, on points with different obstructions of horizon. Besides that, initialisation time has been investigated for both systems from about 480 measurements, using rover's antenna with metal cover, during a time interval of 0.5, 2 and 5 seconds. Moreover, accuracy, firmware declared accuracy and redundancy of GPS and GNSS RTK measurements have been investigating.  

  18. Review of hybrid laminar flow control systems

    Science.gov (United States)

    Krishnan, K. S. G.; Bertram, O.; Seibel, O.

    2017-08-01

    The aeronautic community always strived for fuel efficient aircraft and presently, the need for ecofriendly aircraft is even more, especially with the tremendous growth of air traffic and growing environmental concerns. Some of the important drivers for such interests include high fuel prices, less emissions requirements, need for more environment friendly aircraft to lessen the global warming effects. Hybrid laminar flow control (HLFC) technology is promising and offers possibility to achieve these goals. This technology was researched for decades for its application in transport aircraft, and it has achieved a new level of maturity towards integration and safety and maintenance aspects. This paper aims to give an overview of HLFC systems research and associated flight tests in the past years both in the US and in Europe. The review makes it possible to distinguish between the successful approaches and the less successful or outdated approaches in HLFC research. Furthermore, the technology status shall try to produce first estimations regarding the mass, power consumption and performance of HLFC systems as well as estimations regarding maintenance requirements and possible subsystem definitions.

  19. Electric and Hybrid Vehicle System Research and Development Project: Hybrid Vehicle Potential Assessment. Volume 1. Summary

    Energy Technology Data Exchange (ETDEWEB)

    Surber, F.T.

    1979-09-30

    The results of investigations conducted under Ce Hybrid Vehicle Potential Assessment Task are reported in 10 volumes. This volume contains an overview of the study and its results. The purpose of the overall study was to determine if the petroleum fuel savings achievable through the use of hybrid electric vehicles is worth the R and D expenditures needed to develop the hybrid vehicles and to determine R and D priorities. It was concluded that by the year 2010 hybrid vehicles could replace 80% of the automotive power that would otherwise be produced from petroleum fuels; the public should not suffer any mobility loss through the use of hybrid vehicles; high initial and life-cycle costs are a limiting factor; and R and D funds should be spent for systems design and the development of low-cost batteries and controllers. (LCL)

  20. High Density Polyethylene Composites Reinforced with Hybrid Inorganic Fillers: Morphology, Mechanical and Thermal Expansion Performance

    Directory of Open Access Journals (Sweden)

    Birm-June Kim

    2013-09-01

    Full Text Available The effect of individual and combined talc and glass fibers (GFs on mechanical and thermal expansion performance of the filled high density polyethylene (HDPE composites was studied. Several published models were adapted to fit the measured tensile modulus and strength of various composite systems. It was shown that the use of silane-modified GFs had a much larger effect in improving mechanical properties and in reducing linear coefficient of thermal expansion (LCTE values of filled composites, compared with the use of un-modified talc particles due to enhanced bonding to the matrix, larger aspect ratio, and fiber alignment for GFs. Mechanical properties and LCTE values of composites with combined talc and GF fillers varied with talc and GF ratio at a given total filler loading level. The use of a larger portion of GFs in the mix can lead to better composite performance, while the use of talc can help lower the composite costs and increase its recyclability. The use of 30 wt % combined filler seems necessary to control LCTE values of filled HDPE in the data value range generally reported for commercial wood plastic composites. Tensile modulus for talc-filled composite can be predicted with rule of mixture, while a PPA-based model can be used to predict the modulus and strength of GF-filled composites.

  1. An Application of Reinforcement Learning to Dialogue Strategy Selection in a Spoken Dialogue System for Email

    CERN Document Server

    Walker, M A

    2011-01-01

    This paper describes a novel method by which a spoken dialogue system can learn to choose an optimal dialogue strategy from its experience interacting with human users. The method is based on a combination of reinforcement learning and performance modeling of spoken dialogue systems. The reinforcement learning component applies Q-learning (Watkins, 1989), while the performance modeling component applies the PARADISE evaluation framework (Walker et al., 1997) to learn the performance function (reward) used in reinforcement learning. We illustrate the method with a spoken dialogue system named ELVIS (EmaiL Voice Interactive System), that supports access to email over the phone. We conduct a set of experiments for training an optimal dialogue strategy on a corpus of 219 dialogues in which human users interact with ELVIS over the phone. We then test that strategy on a corpus of 18 dialogues. We show that ELVIS can learn to optimize its strategy selection for agent initiative, for reading messages, and for summari...

  2. Improving Diagnosability of Hybrid Systems through Active Diagnosis

    Data.gov (United States)

    National Aeronautics and Space Administration — Fault diagnosis is key to ensuring system safety through fault-adaptive control. This task is diffcult in hybrid systems with combined continuous and discrete...

  3. Comparison of metallization systems for thin film hybrid microcircuits

    Energy Technology Data Exchange (ETDEWEB)

    Hines, R.A.; Raut, M.K.

    1980-08-01

    Five metallization systems were evaluated for fabricating thin film hybrid microcircuits. The titanium/palladium/electroplated gold system proved superior in terms of thermocompression bondability, corrosion resistance, and solderability.

  4. Structural performance of new thin-walled concrete sandwich panel system reinforced with bfrp shear connectors

    DEFF Research Database (Denmark)

    Hodicky, Kamil; Hulin, Thomas; Schmidt, Jacob Wittrup

    2013-01-01

    This paper presents a new thin-walled concrete sandwich panel system reinforced with basalt fiber-reinforced plastic (BFRP) with optimum structural performances and a high thermal resistance developed by Connovate and Technical University of Denmark. The shear connecting system made of a BFRP grid...... is described and provides information on the structural design with its advantages. Experimental and numerical investigations of the BFRP connecting systems were performed. The experimental program included testing of small scale specimens by applying shear (push-off) loading and semi-full scale specimens...

  5. Glass Reinforcement of Various Epoxy Resins-Polyurea Systems

    Science.gov (United States)

    Joshi, Medha; Jauhari, Smita

    2012-07-01

    Polyureas (PUs) were prepared by the polycondensation reaction of disperse dyes containing -NH2 group and toluene 2, 4-diisocyanate. The disperse dyes have been prepared by coupling of various 2-diazobenzothiazoles with 1,3-benzenediamine. All the PUs were characterized by elemental analysis, spectral studies, number average molecular weight ( {overline{{Mn}} } ), and thermogravimetry. Further reaction of PUs was carried out with an epoxy resin (i.e., DGEBA). The curing study of prepared resins was monitored by differential scanning calorimeter (DSC). Based on DSC, thermograms glass fiber-reinforced composites have been laminated and characterized by chemical, mechanical, and electrical properties. The unreinforced cured resins were subjected to thermogravimetric analysis (TGA). The laminated composites showed excellent resistance properties against chemicals and good mechanical and electrical properties.

  6. Nuclear Hybrid Energy System Modeling: RELAP5 Dynamic Coupling Capabilities

    Energy Technology Data Exchange (ETDEWEB)

    Piyush Sabharwall; Nolan Anderson; Haihua Zhao; Shannon Bragg-Sitton; George Mesina

    2012-09-01

    The nuclear hybrid energy systems (NHES) research team is currently developing a dynamic simulation of an integrated hybrid energy system. A detailed simulation of proposed NHES architectures will allow initial computational demonstration of a tightly coupled NHES to identify key reactor subsystem requirements, identify candidate reactor technologies for a hybrid system, and identify key challenges to operation of the coupled system. This work will provide a baseline for later coupling of design-specific reactor models through industry collaboration. The modeling capability addressed in this report focuses on the reactor subsystem simulation.

  7. Bond graph model-based fault diagnosis of hybrid systems

    CERN Document Server

    Borutzky, Wolfgang

    2015-01-01

    This book presents a bond graph model-based approach to fault diagnosis in mechatronic systems appropriately represented by a hybrid model. The book begins by giving a survey of the fundamentals of fault diagnosis and failure prognosis, then recalls state-of-art developments referring to latest publications, and goes on to discuss various bond graph representations of hybrid system models, equations formulation for switched systems, and simulation of their dynamic behavior. The structured text: • focuses on bond graph model-based fault detection and isolation in hybrid systems; • addresses isolation of multiple parametric faults in hybrid systems; • considers system mode identification; • provides a number of elaborated case studies that consider fault scenarios for switched power electronic systems commonly used in a variety of applications; and • indicates that bond graph modelling can also be used for failure prognosis. In order to facilitate the understanding of fault diagnosis and the presented...

  8. Capture efficiency measurement of pollutants over a workbench with the reinforced slot exhaust system

    Directory of Open Access Journals (Sweden)

    Pavelek M.

    2013-04-01

    Full Text Available The paper deals with the measurement of the capture efficiency of pollutants by the slot reinforced exhaust system situated in two positions over the workbench. The slot reinforced exhaust system, which is known as REEXS, is the traditional slot exhaust hood equipped with an air supply inlet that intensifies exhausting along the axis of the exhaust hood. It can operate in traditional or reinforced exhaust modes. Measurements were made for the same air velocity in the suction slot and with the different momentum flux ratio of supplied and exhausted air flow. The tracer gas method was used for the capture efficiency measurement of the system. As the tracer gas the carbon dioxide was chosen. The knowledge of the shape and range of the effective exhaust area for various configurations in front of the exhaust hood is important for the exhaust hood setting according to a source of pollutants.

  9. Hybrid Recommender System for Joining Virtual Communities

    Directory of Open Access Journals (Sweden)

    Leila Esmaeili

    2012-03-01

    Full Text Available The variety of social networks and virtual communities has created problematic for users of different ages and preferences; in addition, since the true nature of groups is not clearly outlined, users are uncertain about joining various virtual groups and usually face the trouble of joining the undesired ones. As a solution, in this study, we introduced the hybrid community recommender system which offers customized recommendations based on user preferences. Although techniques such as content based filtering and collaborative filtering methods are available, these techniques are not enough efficient and in some cases make problems and bring limitations to users. Our method is based on a combination of content based filtering and collaborative filtering methods. It is created by selecting related features of users based on supervised entropy as well as using association rules and classification method. Supposing users in each community or group share similar characteristics, by hierarchical clustering, heterogeneous members are identified and removed. Unlike other methods, this is also applicable for users who have just joined the social network where they do not have any connections or group memberships. In such situations, this method could still offer recommendations.

  10. Polymer hybrid materials for planar optronic systems

    Science.gov (United States)

    Körner, Martin; Prucker, Oswald; Rühe, Jürgen

    2015-09-01

    Planar optronic systems made entirely from polymeric functional materials on polymeric foils are interesting architectures for monitoring and sensing applications. Key components in this regard are polymer hybrid materials with adjustable optical properties. These materials can then be processed into optical components such as waveguides for example by using embossing techniques. However, the resulting microstructures have often low mechanical or thermal stability which quickly leads to a degradation of the microstructures accompanied often by a complete loss of function. A simple and versatile way to increase the thermal and mechanical stability of polymers is to connect the individual chains to a polymer network by using thermally or photochemically reactive groups. Upon excitation, these groups form reactive intermediates such as radicals or nitrenes which then crosslink with adjacent C-H-groups through a C,H insertion reaction (CHic = C,H insertion based crosslinking). To generate waveguide structures a PDMS stamp is filled with the waveguide core material e.g. poly(methylmethacrylate) (PMMA), which is modified with a few mol% of the thermal crosslinker and hot embossed onto a foil substrate e.g. PMMA. In this one-step hot embossing process polymer ridge waveguides are formed and simultaneously the polymer becomes crosslinked. Due to the reaction across the boundary between waveguide and substrate it is also possible to combine initially incompatible polymers for the waveguide and the substrate foil. The thermomechanical properties of the obtained materials are studied.

  11. Macroevolutionary data suggest a role for reinforcement in pollination system shifts

    NARCIS (Netherlands)

    Niet, van der T.; Johnson, S.D.; Linder, H.P.

    2006-01-01

    Reproductive isolation can evolve either as a by-product of divergent selection or through reinforcement. We used the Cape flora of South Africa, known for its high level of pollination specialization, as a model system to test the potential role of shifts in pollination system in the speciation

  12. Macroevolutionary data suggest a role for reinforcement in pollination system shifts

    NARCIS (Netherlands)

    Niet, van der T.; Johnson, S.D.; Linder, H.P.

    2006-01-01

    Reproductive isolation can evolve either as a by-product of divergent selection or through reinforcement. We used the Cape flora of South Africa, known for its high level of pollination specialization, as a model system to test the potential role of shifts in pollination system in the speciation pro

  13. Battery control system for hybrid vehicle and method for controlling a hybrid vehicle battery

    Science.gov (United States)

    Bockelmann, Thomas R [Battle Creek, MI; Hope, Mark E [Marshall, MI; Zou, Zhanjiang [Battle Creek, MI; Kang, Xiaosong [Battle Creek, MI

    2009-02-10

    A battery control system for hybrid vehicle includes a hybrid powertrain battery, a vehicle accessory battery, and a prime mover driven generator adapted to charge the vehicle accessory battery. A detecting arrangement is configured to monitor the vehicle accessory battery's state of charge. A controller is configured to activate the prime mover to drive the generator and recharge the vehicle accessory battery in response to the vehicle accessory battery's state of charge falling below a first predetermined level, or transfer electrical power from the hybrid powertrain battery to the vehicle accessory battery in response to the vehicle accessory battery's state of charge falling below a second predetermined level. The invention further includes a method for controlling a hybrid vehicle powertrain system.

  14. Investigation of the photovoltaic cell/ thermoelectric element hybrid system performance

    Science.gov (United States)

    Cotfas, D. T.; Cotfas, P. A.; Machidon, O. M.; Ciobanu, D.

    2016-06-01

    The PV/TEG hybrid system, consisting of the photovoltaic cells and thermoelectric element, is presented in the paper. The dependence of the PV/TEG hybrid system parameters on the illumination levels and the temperature is analysed. The maxim power values of the photovoltaic cell, of the thermoelectric element and of the PV/TEG system are calculated and a comparison between them is presented and analysed. An economic analysis is also presented.

  15. A simulation approach to sizing hybrid photovoltaic and wind systems

    Science.gov (United States)

    Anderson, L. A.

    1983-12-01

    A simulation approach to sizing hybrid photovoltaic and wind systems provides a combination of components to realize zero downtime and minimum initial or life-cycle cost. Using Dayton, OH as a test site for weather data, cost advantages in the neighborhood of four are predicted for a hybrid system with battery storage when compared to a wind-energy-only system for the same electrical load.

  16. Sizing and Simulation of PV-Wind Hybrid Power System

    OpenAIRE

    Mustafa Engin

    2013-01-01

    A sizing procedure is developed for hybrid system with the aid of mathematical models for photovoltaic cell, wind turbine, and battery that are readily present in the literature. This sizing procedure can simulate the annual performance of different kinds of photovoltaic-wind hybrid power system structures for an identified set of renewable resources, which fulfills technical limitations with the lowest energy cost. The output of the program will display the performance of the system during t...

  17. Renewable energy systems in Mexico: Installation of a hybrid system

    Science.gov (United States)

    Pate, Ronald C.

    1993-05-01

    Sandia has been providing technical leadership on behalf of DOE and CORECT on a working level cooperative program with Mexico on renewable energy (PROCER). As part of this effort, the Sandia Design Assistance Center (DAC) and the solar energy program staff at Instituto de Investigaciones Electricas (IIE) in Cuernavaca, Mexico, recently reached agreement on a framework for mutually beneficial technical collaboration on the monitoring and field evaluation of renewable energy systems in Mexico, particularly village-scale hybrid systems. This trip was made for the purpose of planning the details for the joint installation of a data acquisition system (DAS) on a recently completed PV/Wind/Diesel hybrid system in the village of Xcalac on the Southeast coast of the state of Quintana Roo, Mexico. The DAS installation will be made during the week of March 15, 1993. While in Mexico, discussions were also held with personnel from.the National Autonomous University of Mexico (UNAM) Solar Energy Laboratory and several private sector companies with regard to renewable energy project activities and technical and educational support needs in Mexico.

  18. Exact Verification of Hybrid Systems Based on Bilinear SOS Representation

    CERN Document Server

    Yang, Zhengfeng; Lin, Wang

    2012-01-01

    In this paper, we address the problem of safety verification of nonlinear hybrid systems and stability analysis of nonlinear autonomous systems. A hybrid symbolic-numeric method is presented to compute exact inequality invariants of hybrid systems and exact estimates of regions of attraction of autonomous systems efficiently. Some numerical invariants of a hybrid system or an estimate of region of attraction can be obtained by solving a bilinear SOS program via PENBMI solver or iterative method, then the modified Newton refinement and rational vector recovery techniques are applied to obtain exact polynomial invariants and estimates of regions of attraction with rational coefficients. Experiments on some benchmarks are given to illustrate the efficiency of our algorithm.

  19. Activity of the positive and negative reinforcement motivation systems and baseline arterial blood pressure in humans.

    Science.gov (United States)

    Aftanas, L I; Sidorova, P V; Pavlov, S V; Makhnev, V P; Korenek, V V; Reva, N V; Amstislavskaya, T G

    2008-10-01

    The aim of the present work was to identify possible associations between individual balances in the activity of the positive and negative reinforcement motivation systems using a method based on emotional modulation of the startle reaction (EMSR) by motivationally significant emotionally positive and negative contextual visual stimuli and measures of cardiovascular system activity. Studies were performed using healthy males (mean age 30.29 +/- 9.8 years) with normal and first-episode excessive increases in arterial blood pressure (systolic blood pressure to greater than 140 mmHg, diastolic to greater than 90 mmHg). Cluster analysis of EMSR data identified groups of individuals with different activity profiles for the positive and negative reinforcement systems. Groups of subjects with changes in the balance of activity towards a lower level of positive reinforcement system activity (smaller startle reflexes to positive contextual stimuli) or a higher level of negative reinforcement system activity (larger startle reactions to threatening contextual stimuli) showed significantly greater baseline SBP and DBP. The possible mechanisms of the modulatory influences of the balance of system activities on autonomic vascular regulatory processes are discussed.

  20. Direct hydrogen fuel cell systems for hybrid vehicles

    Science.gov (United States)

    Ahluwalia, Rajesh K.; Wang, X.

    Hybridizing a fuel cell system with an energy storage system offers an opportunity to improve the fuel economy of the vehicle through regenerative braking and possibly to increase the specific power and decrease the cost of the combined energy conversion and storage systems. Even in a hybrid configuration it is advantageous to operate the fuel cell system in a load-following mode and use the power from the energy storage system when the fuel cell alone cannot meet the power demand. This paper discusses an approach for designing load-following fuel cell systems for hybrid vehicles and illustrates it by applying it to pressurized, direct hydrogen, polymer-electrolyte fuel cell (PEFC) systems for a mid-size family sedan. The vehicle level requirements relative to traction power, response time, start-up time and energy conversion efficiency are used to select the important parameters for the PEFC stack, air management system, heat rejection system and the water management system.

  1. Impact mechanical properties of concrete reinforced with hybrid carbon fibers%碳纤维混杂纤维混凝土抗冲击性能研究

    Institute of Scientific and Technical Information of China (English)

    王璞; 黄真; 周岱; 王贤栋; 张昌

    2012-01-01

    对比美国混凝土学会的混凝土落锤冲击试验装置,自行设计了混凝土落锤弯曲冲击试验装置,进行了不同几何尺寸及弹性模量的碳纤维、钢纤维和聚丙烯纤维混凝土的抗冲击力学性能试验研究.分析比较了不同纤维几何尺寸和弹性模量、种类和掺量对混杂纤维混凝土抗冲击性能的影响和增强机理.通过定义混杂效应系数,可定量评价混凝土抗冲击力学性能的正混杂效应.研究表明:纤维可以明显提高混凝土的抗冲击强度,其中碳纤维混杂纤维混凝土的提高幅度更为显著.%An impact bending test method for concrete and test equipments were developed compared with impact test methods suggested by the ACI, and the impact mechanical properties of hybrid fiber reinforced concrete ( HyFRC) with different kinds and percents of carbon fiber, steel fibers and polypropylene fiber were investigated, and the effect of fiber types and contents on HyFRC's impact performance was analyzed. A hybrid factor to evaluate quantitatively the positive hybrid effect of concrete anti-impact behavior was suggested. The study results showed that hybrid carbon fiber reinforced concrete has better impact resistance capacity compared with that of ofher concrete.

  2. Wind Solar Hybrid System Rectifier Stage Topology Simulation

    Directory of Open Access Journals (Sweden)

    Anup M. Gakare

    2014-06-01

    Full Text Available This paper presents power-control strategies of a grid-connected hybrid generation system with versatile power transfer. The hybrid system allows maximum utilization of freely available renewable sources like wind and photovoltaic energies. This paper presents a new system configuration of the multi input rectifier stage for a hybrid wind and photovoltaic energy system. This configuration allows the two sources to supply the load simultaneously depending on the availability of the energy sources maximum power from the sun when it is available. An adaptive MPPT algorithm with a standard perturbs and observed method will be used for the Photo Voltaic system. The main advantage of the hybrid system is to give continuous power supply to the load. The gating pulses to the inverter switches are implemented with conventional and fuzzy controller. This hybrid wind-photo voltaic system is modeled in MATLAB/ SIMULINK environment. Simulation circuit is analyzed and results are presented for this hybrid wind and solar energy system.

  3. Nuclear Hybrid Energy Systems FY16 Modeling Efforts at ORNL

    Energy Technology Data Exchange (ETDEWEB)

    Cetiner, Sacit M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Greenwood, Michael Scott [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Harrison, Thomas J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Qualls, A. L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Guler Yigitoglu, Askin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Fugate, David W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-09-01

    A nuclear hybrid system uses a nuclear reactor as the basic power generation unit. The power generated by the nuclear reactor is utilized by one or more power customers as either thermal power, electrical power, or both. In general, a nuclear hybrid system will couple the nuclear reactor to at least one thermal power user in addition to the power conversion system. The definition and architecture of a particular nuclear hybrid system is flexible depending on local markets needs and opportunities. For example, locations in need of potable water may be best served by coupling a desalination plant to the nuclear system. Similarly, an area near oil refineries may have a need for emission free hydrogen production. A nuclear hybrid system expands the nuclear power plant from its more familiar central power station role by diversifying its immediately and directly connected customer base. The definition, design, analysis, and optimization work currently performed with respect to the nuclear hybrid systems represents the work of three national laboratories. Idaho National Laboratory (INL) is the lead lab working with Argonne National Laboratory (ANL) and Oak Ridge National Laboratory. Each laboratory is providing modeling and simulation expertise for the integration of the hybrid system.

  4. Design of Magnetic Flux Feedback Controller in Hybrid Suspension System

    Directory of Open Access Journals (Sweden)

    Wenqing Zhang

    2013-01-01

    Full Text Available Hybrid suspension system with permanent magnet and electromagnet consumes little power consumption and can realize larger suspension gap. But realizing stable suspension of hybrid magnet is a tricky problem in the suspension control sphere. Considering from this point, we take magnetic flux signal as a state variable and put this signal back to suspension control system. So we can get the hybrid suspension mathematical model based on magnetic flux signal feedback. By application of MIMO feedback linearization theory, we can further realize linearization of the hybrid suspension system. And then proportion, integral, differentiation, magnetic flux density B (PIDB controller is designed. Some hybrid suspension experiments have been done on CMS04 magnetic suspension bogie of National University of Defense Technology (NUDT in China. The experiments denote that the new hybrid suspension control algorithm based on magnetic flux signal feedback designed in this paper has more advantages than traditional position-current double cascade control algorithm. Obviously, the robustness and stability of hybrid suspension system have been enhanced.

  5. A Structural Model Decomposition Framework for Hybrid Systems Diagnosis

    Science.gov (United States)

    Daigle, Matthew; Bregon, Anibal; Roychoudhury, Indranil

    2015-01-01

    Nowadays, a large number of practical systems in aerospace and industrial environments are best represented as hybrid systems that consist of discrete modes of behavior, each defined by a set of continuous dynamics. These hybrid dynamics make the on-line fault diagnosis task very challenging. In this work, we present a new modeling and diagnosis framework for hybrid systems. Models are composed from sets of user-defined components using a compositional modeling approach. Submodels for residual generation are then generated for a given mode, and reconfigured efficiently when the mode changes. Efficient reconfiguration is established by exploiting causality information within the hybrid system models. The submodels can then be used for fault diagnosis based on residual generation and analysis. We demonstrate the efficient causality reassignment, submodel reconfiguration, and residual generation for fault diagnosis using an electrical circuit case study.

  6. DESIGNING A HYBRID INTELLIGENT MINING SYSTEM FOR CREDIT RISK EVALUATION

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this study,a novel hybrid intelligent mining system integrating rough sets theory and support vector machines is developed to extract efficiently association rules from original information table for credit risk evaluation and analysis.In the proposed hybrid intelligent system,support vector machines are used as a tool to extract typical features and filter its noise,which are different from the previous studies where rough sets were only used as a preprocessor for support vector machines.Such an approach could reduce the information table and generate the final knowledge from the reduced information table by rough sets.Therefore,the proposed hybrid intelligent system overcomes the diffi-culty of extracting rules from a trained support vector machine classifier and possesses the robustness which is lacking for rough-set-based approaches.In addition,the effectiveness of the proposed hybrid intelligent system is illustrated with two real-world credit datasets.

  7. Asymptotic Stabilizability of a Class of Stochastic Nonlinear Hybrid Systems

    Directory of Open Access Journals (Sweden)

    Ewelina Seroka

    2015-01-01

    Full Text Available The problem of the asymptotic stabilizability in probability of a class of stochastic nonlinear control hybrid systems (with a linear dependence of the control with state dependent, Markovian, and any switching rule is considered in the paper. To solve the issue, the Lyapunov technique, including a common, single, and multiple Lyapunov function, the hybrid control theory, and some results for stochastic nonhybrid systems are used. Sufficient conditions for the asymptotic stabilizability in probability for a considered class of hybrid systems are formulated. Also the stabilizing control in a feedback form is considered. Furthermore, in the case of hybrid systems with the state dependent switching rule, a method for a construction of stabilizing switching rules is proposed. Obtained results are illustrated by examples and numerical simulations.

  8. Evolutionary design of discrete controllers for hybrid mechatronic systems

    DEFF Research Database (Denmark)

    Dupuis, Jean-Francois; Fan, Zhun; Goodman, Erik

    2015-01-01

    This paper investigates the issue of evolutionary design of controllers for hybrid mechatronic systems. Finite State Automaton (FSA) is selected as the representation for a discrete controller due to its interpretability, fast execution speed and natural extension to a statechart, which is very...... popular in industrial applications. A case study of a two-tank system is used to demonstrate that the proposed evolutionary approach can lead to a successful design of an FSA controller for the hybrid mechatronic system, represented by a hybrid bond graph. Generalisation of the evolved FSA controller...... of the evolutionary design of controllers for hybrid mechatronic systems. Finally, some important future research directions are pointed out, leading to the major work of the succeeding part of the research....

  9. A Novel Single Phase Hybrid Switched Reluctance Motor Drive System

    DEFF Research Database (Denmark)

    Liang, Jianing; Xu, Guoqing; Jian, Linni

    2011-01-01

    In this paper, a novel single phase hybrid switched reluctance motor(SRM) drive system is proposed. It integrated a single phase hybrid SRM and a novel single phase boost converter. This motor can reduce the number of phase switch. And the permanent magnet which is used in the motor can improve t...... SRM reduce the negative torque before zero-crossing point of torque curve, and build desired phase current to generate more power. Some experimental results are done to verify the performance of proposed hybrid SRM drive system....

  10. Hybrid synchronization of two independent chaotic systems on complex network

    Indian Academy of Sciences (India)

    NIAN FUZHONG; LIU WEILONG

    2016-06-01

    The real network nodes are always interfered by other messages. So, how to realize the hybrid synchronization of two independent chaotic systems based on the complex network is very important. To solve this problem, two other problems should be considered. One is how the same network node of the complex network was affected by different information sources. Another is how to achieve hybrid synchronization on the network. In this paper, the theoretical analysis andnumerical simulation on various complex networks are implemented. The results indicate that the hybrid synchronization of two independent chaotic systems is feasible.

  11. Passive Control Reinforced Concrete Frame Mechanism with High Strength Reinforcements and Its Potential Benefits Against Earthquakes

    Institute of Scientific and Technical Information of China (English)

    Asad Ullah Qazi; YE Lieping; LU Xinzheng

    2006-01-01

    Severe earthquakes continue to cause major catastrophes. Many devices in active, hybrid, and semi-active structural control systems which are used as controllable force devices are costly to build and maintain. The passive control reinforced concrete frame (PCRCF) reinforced with high strength steel only in the columns presented here provides structural systems more resistance to lateral earthquake loadings at comparatively lower cost. The effectiveness is demonstrated by a nonlinear static analysis using fiber model for a single story single bay frame. The study shows that the use of high performance steel in columns prevents formation of plastic hinges at the critical column base sections and failures are always initiated by reinforcement yielding at the beam ends. Furthermore, after experiencing severe lateral drift, the passive control design has small residual displacements compared to ordinary reinforced concrete frames. PCRCF rehabilitation and strengthening can be achieved more easily as compared with ordinary reinforced concrete frame.

  12. User-interfaces for hybrid systems: Analysis and design through hybrid reachability

    Science.gov (United States)

    Oishi, Meeko Mitsuko Karen

    Hybrid systems combine discrete state dynamics, which model mode switching, with continuous state dynamics, which model the physical processes themselves. Applications of hybrid system theory to automated systems have traditionally assumed that the controller itself is an automaton which runs in parallel with the system under control. We model human interaction with hybrid systems, which involves the user; the automation's discrete mode-logic, and the underlying continuous dynamics of the physical system. Often in safety-critical systems, user-interfaces display a reduced set of information about the entire system, however must still provide adequate information and must not confuse the user. We present (1) a method of designing a discrete event system abstraction of the hybrid system, in order to verify or design user-interfaces for hybrid human-automation systems, and (2) the relationship between user-interfaces and discrete observability properties. Using a hybrid computational tool for reachability, we find the largest region in which the system can always remain---this is the safe region of operation. By implementing a controller which arises from this computation, we mathematically guarantee that this safe region is invariant. Assigning discrete states to the computed invariant regions, we create a discrete event system from this hybrid system with safety restrictions. This abstraction can then be used in existing interface verification and design methods. A user-interface, modeled as a discrete system, must, not only be reduced (extraneous information has been eliminated), but also "immediately observable". We derive conditions for immediate observability, in which the current state can be constructed from the current output and last occurring event. Based on finite state machine state-reduction techniques, we synthesize an output for remote user-interfaces which fulfills this property. Aircraft are prime examples of complex, safety-critical systems. In

  13. ON THE STABILIZATION OF THE LINEAR HYBRID SYSTEM STRUCTURE

    Directory of Open Access Journals (Sweden)

    Kirillov

    2014-11-01

    Full Text Available The linear control hybrid system, consisting of a fi- nite set of subsystems (modes having different dimensions, is considered. The moments of reset time are determined by some complementary function – evolutionary time. This function satisfies the special complementary ordinary differential equation. The mode stabilization problem is solved for some class of piecewise linear controls. The method of stabilization relies on the set of invariant planes, the existence of which is due to the special form of the hybrid system.

  14. Hybrid architecture active wavefront sensing and control system, and method

    Science.gov (United States)

    Feinberg, Lee D. (Inventor); Dean, Bruce H. (Inventor); Hyde, Tristram T. (Inventor)

    2011-01-01

    According to various embodiments, provided herein is an optical system and method that can be configured to perform image analysis. The optical system can comprise a telescope assembly and one or more hybrid instruments. The one or more hybrid instruments can be configured to receive image data from the telescope assembly and perform a fine guidance operation and a wavefront sensing operation, simultaneously, on the image data received from the telescope assembly.

  15. EXPONENTIAL ESTIMATES FOR STOCHASTIC DELAY HYBRID SYSTEMS WITH MARKOVIAN SWITCHING

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper deals with the problem of norm bounds for the solutions of stochastic hybrid systems with Markovian switching and time delay. Based on Lyapunov-Krasovskii theory for functional differential equations and the linear matrix inequality (LMI) approach, mean square exponential estimates for the solutions of this class of linear stochastic hybrid systems are derived. Finally, An example is illustrated to show the applicability and effectiveness of our method.

  16. A modified Adaptive Wavelet PID Control Based on Reinforcement Learning for Wind Energy Conversion System Control

    Directory of Open Access Journals (Sweden)

    REZAZADEH, A.

    2010-05-01

    Full Text Available Nonlinear characteristics of wind turbines and electric generators necessitate complicated and nonlinear control of grid connected Wind Energy Conversion Systems (WECS. This paper proposes a modified self-tuning PID control strategy, using reinforcement learning for WECS control. The controller employs Actor-Critic learning in order to tune PID parameters adaptively. These Actor-Critic learning is a special kind of reinforcement learning that uses a single wavelet neural network to approximate the policy function of the Actor and the value function of the Critic simultaneously. These controllers are used to control a typical WECS in noiseless and noisy condition and results are compared with an adaptive Radial Basis Function (RBF PID control based on reinforcement learning and conventional PID control. Practical emulated results prove the capability and the robustness of the suggested controller versus the other PID controllers to control of the WECS. The ability of presented controller is tested by experimental setup.

  17. Describing Organizations as Reinforcer Systems: A New Use for Job Satisfaction and Employee Attitude Surveys

    Science.gov (United States)

    Dawis, Rene V.; And Others

    1974-01-01

    Job satisfaction data on managerial personnel were used to illustrate how organizations can be differentiated and described as reinforcer systems. Twenty-seven specific satisfaction scales were regressed on overall job satisfaction. Overall satisfaction was found to be determined mainly by scales concerning challenge of the job and prospects of…

  18. Oxidation of carbon fiber surfaces for use as reinforcement in high-temperature cementitious material systems

    Science.gov (United States)

    Sugama, Toshifumi

    1990-01-01

    The interfacial bond characteristics between carbon fiber and a cement matrix, in high temperature fiber-reinforced cementitious composite systems, can be improved by the oxidative treatment of the fiber surfaces. Compositions and the process for producing the compositions are disclosed.

  19. Modelling of horn-type loudspeakers for outdoor sound reinforcement systems

    DEFF Research Database (Denmark)

    Schuhmacher, Andreas; Rasmussen, Karsten Bo

    1999-01-01

    -type loudspeakers is made. The agreement between measured and calculated results is very good provided that a sufficient number of modes is included in the simulation. Simulation models of this kind represent one of the first steps towards a CAD tool for outdoor sound reinforcement systems....

  20. Application of Hybrid Dynamical Theory to the Cardiovascular System

    KAUST Repository

    Laleg-Kirati, Taous-Meriem

    2014-10-14

    In hybrid dynamical systems, the state evolves in continuous time as well as in discrete modes activated by internal conditions or by external events. In the recent years, hybrid systems modeling has been used to represent the dynamics of biological systems. In such systems, discrete behaviors might originate from unexpected changes in normal performance, e.g., a transition from a healthy to an abnormal condition. Simplifications, model assumptions, and/or modeled (and ignored) nonlinearities can be represented by sudden changes in the state. Modeling cardiovascular system (CVS), one of the most fascinating but most complex human physiological systems, with a hybrid approach, is the focus of this chapter. The hybrid property appears naturally in the CVS thanks to the presence of valves which, depending on their state (closed or open), divide the cardiac cycle into four phases. This chapter shows how hybrid models can be used for modeling the CVS. In addition, it describes a preliminary study on the detection of some cardiac anomalies based on the hybrid model and using the standard observer-based approach.

  1. Note on the Lax Pair of a Coupled Hybrid System

    Institute of Scientific and Technical Information of China (English)

    LIU Ping; FU Pei-Kai

    2012-01-01

    The hybrid lattice,known as a discrete Korteweg-de Vries (KdV) equation,is found to be a discrete modified Korteweg-de Vries (mKdV) equation.The coupled hybrid lattice,which is pointed out to be a discrete coupled KdV system,is also found to be a discrete form of a coupled mKdV system.New lax pairs for the single and coupled discrete hybrid systems are proposed as a different study from previous ones.%The hybrid lattice, known as a discrete Korteweg-de Vries (KdV) equation, is found to be a discrete modified Korteweg-de Vries (mKdV) equation. The coupled hybrid lattice, which is pointed out to be a discrete coupled KdV system, is also found to be a discrete form of a coupled mKdV system. New lax pairs for the single and coupled discrete hybrid systems are proposed as a different study from previous ones.

  2. Mars Hybrid Propulsion System Trajectory Analysis. Part II; Cargo Missions

    Science.gov (United States)

    Chai, Patrick R.; Merrill, Raymond G.; Qu, Min

    2015-01-01

    NASA's Human Spaceflight Architecture Team is developing a reusable hybrid transportation architecture in which both chemical and electric propulsion systems are used to send crew and cargo to Mars destinations such as Phobos, Deimos, the surface of Mars, and other orbits around Mars. By combining chemical and electrical propulsion into a single spaceship and applying each where it is more effective, the hybrid architecture enables a series of Mars trajectories that are more fuel-efficient than an all chemical architecture without significant increases in flight times. This paper shows the feasibility of the hybrid transportation architecture to pre-deploy cargo to Mars and Phobos in support of the Evolvable Mars Campaign crew missions. The analysis shows that the hybrid propulsion stage is able to deliver all of the current manifested payload to Phobos and Mars through the first three crew missions. The conjunction class trajectory also allows the hybrid propulsion stage to return to Earth in a timely fashion so it can be reused for additional cargo deployment. The 1,100 days total trip time allows the hybrid propulsion stage to deliver cargo to Mars every other Earth-Mars transit opportunity. For the first two Mars surface mission in the Evolvable Mars Campaign, the short trip time allows the hybrid propulsion stage to be reused for three round-trip journeys to Mars, which matches the hybrid propulsion stage's designed lifetime for three round-trip crew missions to the Martian sphere of influence.

  3. Reachability computation for hybrid systems with Ariadne

    NARCIS (Netherlands)

    L. Benvenuti; D. Bresolin; A. Casagrande; P.J. Collins (Pieter); A. Ferrari; E. Mazzi; T. Villa; A. Sangiovanni-Vincentelli

    2008-01-01

    htmlabstractAriadne is an in-progress open environment to design algorithms for computing with hybrid automata, that relies on a rigorous computable analysis theory to represent geometric objects, in order to achieve provable approximation bounds along the computations. In this paper we discuss the

  4. A hybrid reconfigurable solar and wind energy system

    Science.gov (United States)

    Gadkari, Sagar A.

    We study the feasibility of a novel hybrid solar-wind hybrid system that shares most of its infrastructure and components. During periods of clear sunny days the system will generate electricity from the sun using a parabolic concentrator. The concentrator is formed by individual mirror elements and focuses the light onto high intensity vertical multi-junction (VMJ) cells. During periods of high wind speeds and at night, the same concentrator setup will be reconfigured to channel the wind into a wind turbine which will be used to harness wind energy. In this study we report on the feasibility of this type of solar/wind hybrid energy system. The key mechanisms; optics, cooling mechanism of VMJ cells and air flow through the system were investigated using simulation tools. The results from these simulations, along with a simple economic analysis giving the levelized cost of energy for such a system are presented. An iterative method of design refinement based on the simulation results was used to work towards a prototype design. The levelized cost of the system achieved in the economic analysis shows the system to be a good alternative for a grid isolated site and could be used as a standalone system in regions of lower demand. The new approach to solar wind hybrid system reported herein will pave way for newer generation of hybrid systems that share common infrastructure in addition to the storage and distribution of energy.

  5. Energy Efficient Hybrid Dual Axis Solar Tracking System

    Directory of Open Access Journals (Sweden)

    Rashid Ahammed Ferdaus

    2014-01-01

    Full Text Available This paper describes the design and implementation of an energy efficient solar tracking system from a normal mechanical single axis to a hybrid dual axis. For optimizing the solar tracking mechanism electromechanical systems were evolved through implementation of different evolutional algorithms and methodologies. To present the tracker, a hybrid dual-axis solar tracking system is designed, built, and tested based on both the solar map and light sensor based continuous tracking mechanism. These light sensors also compare the darkness and cloudy and sunny conditions assisting daily tracking. The designed tracker can track sun’s apparent position at different months and seasons; thereby the electrical controlling device requires a real time clock device for guiding the tracking system in seeking solar position for the seasonal motion. So the combination of both of these tracking mechanisms made the designed tracker a hybrid one. The power gain and system power consumption are compared with a static and continuous dual axis solar tracking system. It is found that power gain of hybrid dual axis solar tracking system is almost equal to continuous dual axis solar tracking system, whereas the power saved in system operation by the hybrid tracker is 44.44% compared to the continuous tracking system.

  6. Hybrid Ventilation with Innovative Heat Recovery—A System Analysis

    Directory of Open Access Journals (Sweden)

    Bengt Hellström

    2013-02-01

    Full Text Available One of the most important factors when low energy houses are built is to have good heat recovery on the ventilation system. However, standard ventilation units use a considerable amount of electricity. This article discusses the consequences on a system level of using hybrid ventilation with heat recovery. The simulation program TRNSYS was used in order to investigate a ventilation system with heat recovery. The system also includes a ground source storage and waste water heat recovery system. The result of the analysis shows that the annual energy gain from ground source storage is limited. However, this is partly a consequence of the fact that the well functioning hybrid ventilation system leaves little room for improvements. The analysis shows that the hybrid ventilation system has potential to be an attractive solution for low energy buildings with a very low need for electrical energy.

  7. DIAGNOSIS WINDOWS PROBLEMS BASED ON HYBRID INTELLIGENCE SYSTEMS

    Directory of Open Access Journals (Sweden)

    SAFWAN O. HASOON

    2013-10-01

    Full Text Available This paper describes the artificial intelligence technologies by integrating Radial Basis Function networks with expert systems to construct a robust hybrid system. The purpose of building the hybrid system is to give recommendations to repair the operating system (Windows problems and troubleshoot the problems that can be repaired. The neural network has unique characteristics which it can complete the uncompleted data, the expert system can't deal with data that is incomplete, but using the neural network individually has some disadvantages which it can't give explanations and recommendations to the problems. The expert system has the ability to explain and give recommendations by using the rules and the human expert in some conditions. Therefore, we have combined the two technologies. The paper will explain the integration methods between the two technologies and which method is suitable to be used in the proposed hybrid system.

  8. Hybrid rocket propulsion systems for outer planet exploration missions

    Science.gov (United States)

    Jens, Elizabeth T.; Cantwell, Brian J.; Hubbard, G. Scott

    2016-11-01

    Outer planet exploration missions require significant propulsive capability, particularly to achieve orbit insertion. Missions to explore the moons of outer planets place even more demanding requirements on propulsion systems, since they involve multiple large ΔV maneuvers. Hybrid rockets present a favorable alternative to conventional propulsion systems for many of these missions. They typically enjoy higher specific impulse than solids, can be throttled, stopped/restarted, and have more flexibility in their packaging configuration. Hybrids are more compact and easier to throttle than liquids and have similar performance levels. In order to investigate the suitability of these propulsion systems for exploration missions, this paper presents novel hybrid motor designs for two interplanetary missions. Hybrid propulsion systems for missions to Europa and Uranus are presented and compared to conventional in-space propulsion systems. The hybrid motor design for each of these missions is optimized across a range of parameters, including propellant selection, O/F ratio, nozzle area ratio, and chamber pressure. Details of the design process are described in order to provide guidance for researchers wishing to evaluate hybrid rocket motor designs for other missions and applications.

  9. Thermal simulation of a cooling system of hybrid commercial vehicles; Thermalsimulation eine Hybrid-LKW-Kuehlsystems

    Energy Technology Data Exchange (ETDEWEB)

    Stroh, Christoph; Schnoerch, Stefan; Rathberger, Christian [Magna Powertrain Engineering Center Steyr GmbH und Co. KG, St. Valentin (Austria)

    2012-11-01

    In the past few years hybrid vehicles have been in the center of automotive engineering efforts, in particular in the field of passenger cars. But hybrid powertrains will also be important for commercial trucks. This focus on hybrid vehicles leads to high demands on thermal management since the additional components in a hybrid vehicle need appropriate cooling or even heating. In the given paper the simulation of a complete cooling system of a hybrid commercial vehicle will be explained. For this virtual examination the commercial 1D thermal management software KULI will be used, a co-simulation with several programs will not be done deliberately. Yet all aspects which are relevant for a global assessment of the thermal management are considered. The main focus is put on the investigation of appropriate concepts for the fluid circuits, including low and high temperature circuits, electric water pumps, etc. Moreover, also a refrigerant circuit with a chiller for active battery cooling will be used, the appropriate control strategy is implemented as well. For simulating transient profiles a simple driving simulation model is included, using road profile, ambient conditions, and various vehicle parameters as input. In addition an engine model is included which enables the investigation of fuel consumption potentials. This simulation model shows how the thermal management of a hybrid vehicle can be investigated with a single program and with reasonable effort. (orig.)

  10. A combined corrosion protection system for reinforced concrete structures using a carbon fibre mesh

    Energy Technology Data Exchange (ETDEWEB)

    Bruns, M.; Raupach, M. [Institut fuer Bauforschung der RWTH Aachen, IBAC, Institute of Building Materials Research of the Technical University of Aachen, Schinkelstrasse 3 Aachen (Germany)

    2004-07-01

    Cathodic Protection (CP) has become a world-wide used method to protect reinforced concrete structures against reinforcement corrosion. Another method to stop or reduce reinforcement corrosion, at least in case of lower chloride contents is the reduction of the water content of the concrete by applying sealing coatings on the concrete surface. At the Institute of Building Materials Research of Aachen University (IBAC) actually a surface protection system is investigated based on the combination of both methods mentioned above. The idea is to protect the reinforcement within the first years after system installation by cathodic protection until the water content of the concrete has decreased to a level due to the surface coating where the corrosion rate of the reinforcement is uncritical and does not lead to any damage. The system investigated, consists of a carbon fibre net embedded in a special mortar layer as impressed current anode for cathodic protection, covered by a 'dense' cement based polymer modified surface coating. In order to investigate the system, it has been installed on a test area on the weathered upper deck of a parking garage in Aachen, Germany. To investigate the effectiveness regarding the reduction of the water content of the concrete the test area was equipped with so called Multiring-Electrodes (MRE) for depth depended measurement of the concrete resistivity. Reference electrodes for potential and depolarization measurements as well a device for automatic measurement of the protection current were installed to investigate the effectiveness of the impressed current cathodic protection. Additionally 3 re bars were embedded into the concrete of the test area using mortar containing 1, 2 or 3 M.-% chloride by weight of cement respectively, to investigate the influence of the chloride content. First results of the MRE-measurements showing already within the first months after system installation a distinct drying of the concrete cover

  11. Reinforced Ultra-Tightly Coupled GPS/INS System for Challenging Environment

    Directory of Open Access Journals (Sweden)

    Xueyun Wang

    2014-01-01

    Full Text Available Among all integration levels currently available for Global Positioning System (GPS and Inertial Navigation System (INS Integrated System, ultra-tightly coupled (UTC GPS/INS system is the best choice for accurate and reliable navigation. Nevertheless the performance of UTC GPS/INS system degrades in challenging environments, such as jamming, changing noise of GPS signals, and high dynamic maneuvers. When low-end Inertial Measurement Units (IMUs based on MEMS sensors are employed, the performance degradation will be more severe. To solve this problem, a reinforced UTC GPS/INS system is proposed. Two techniques are adopted to deal with jamming and high dynamics. Firstly, adaptive integration Kalman filter (IKF based on fuzzy logics is developed to reinforce the antijamming ability. The parameters of membership functions (MFs are adjusted and optimized through self-developed neutral network. Secondly, a Doppler frequency error estimator based on Kalman filter is designed to improve the navigation performance under high dynamics. A complete simulation platform is established to evaluate the reinforced system. Results demonstrate that the proposed system architecture significantly improves navigation performance in challenging environments and it is a more advanced solution to accurate and reliable navigation than traditional UTC GPS/INS system.

  12. Analysis of advanced solar hybrid desiccant cooling systems for buildings

    Energy Technology Data Exchange (ETDEWEB)

    Schlepp, D.; Schultz, K.

    1984-10-01

    This report describes an assessment of the energy savings possible from developing hybrid desiccant/vapor-compression air conditioning systems. Recent advances in dehumidifier design for solar desiccant cooling systems have resulted in a dehumidifier with a low pressure drop and high efficiency in heat and mass transfer. A recent study on hybrid desiccant/vapor compression systems showed a 30%-80% savings in resource energy when compared with the best conventional systems with vapor compression. A system consisting of a dehumidifier with vapor compression subsystems in series was found to be the simplest and best overall performer.

  13. Thermal, mechanical, and physical properties of seaweed/sugar palm fibre reinforced thermoplastic sugar palm Starch/Agar hybrid composites.

    Science.gov (United States)

    Jumaidin, Ridhwan; Sapuan, Salit M; Jawaid, Mohammad; Ishak, Mohamad R; Sahari, Japar

    2017-04-01

    The aim of this research is to investigate the effect of sugar palm fibre (SPF) on the mechanical, thermal and physical properties of seaweed/thermoplastic sugar palm starch agar (TPSA) composites. Hybridized seaweed/SPF filler at weight ratio of 25:75, 50:50 and 75:25 were prepared using TPSA as a matrix. Mechanical, thermal and physical properties of hybrid composites were carried out. Obtained results indicated that hybrid composites display improved tensile and flexural properties accompanied with lower impact resistance. The highest tensile (17.74MPa) and flexural strength (31.24MPa) was obtained from hybrid composite with 50:50 ratio of seaweed/SPF. Good fibre-matrix bonding was evident in the scanning electron microscopy (SEM) micrograph of the hybrid composites' tensile fracture. Fourier transform infrared spectroscopy (FT-IR) analysis showed increase in intermolecular hydrogen bonding following the addition of SPF. Thermal stability of hybrid composites was enhanced, indicated by a higher onset degradation temperature (259°C) for 25:75 seaweed/SPF composites than the individual seaweed composites (253°C). Water absorption, thickness swelling, water solubility, and soil burial tests showed higher water and biodegradation resistance of the hybrid composites. Overall, the hybridization of SPF with seaweed/TPSA composites enhances the properties of the biocomposites for short-life application; that is, disposable tray, plate, etc.

  14. A PRODUCT HYBRID GMRES ALGORITHM FOR NONSYMMETRIC LINEAR SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Bao-jiang Zhong

    2005-01-01

    It has been observed that the residual polynomials resulted from successive restarting cycles of GMRES(m) may differ from one another meaningfully. In this paper, it is further shown that the polynomials can complement one another harmoniously in reducing the iterative residual. This characterization of GMRES(m) is exploited to formulate an efficient hybrid iterative scheme, which can be widely applied to existing hybrid algorithms for solving large nonsymmetric systems of linear equations. In particular, a variant of the hybrid GMRES algorithm of Nachtigal, Reichel and Trefethen (1992) is presented. It is described how the new algorithm may offer significant performance improvements over the original one.

  15. Creep behavior and wear resistance of Al 5083 based hybrid composites reinforced with carbon nanotubes (CNTs) and boron carbide (B{sub 4}C)

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, Ali [Faculty of Materials & Manufacturing Processes, Malek-e-Ashtar University of Technology, Tehran (Iran, Islamic Republic of); Abdollahi, Alireza, E-mail: alirezaabdollahi1366@gmail.com [Faculty of Materials & Manufacturing Processes, Malek-e-Ashtar University of Technology, Tehran (Iran, Islamic Republic of); Biukani, Hootan [Faculty of Engineering, South Tehran Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2015-11-25

    In the current research, aluminum based hybrid composite reinforced with boron carbide (B{sub 4}C) and carbon nanotubes (CNTs) was produced by powder metallurgy method. creep behavior, wear resistance, surface roughness, and hardness of the samples were investigated. To prepare the samples, Al 5083 powder was milled with boron carbide particles and carbon nanotubes using planetary ball mill under argon atmosphere with ball-to-powder weight ratio of 10:1 for 5 h. Afterwards, the milled powders were formed by hot press process at 380{sup °}C and then were sintered at 585{sup °}C under argon atmosphere for 2 h. There was shown to be an increase in hardness values of composite with an increase in B{sub 4}C content. The micrograph of worn surfaces indicate a delamination mechanism due to the presence of CNTs and abrasion mechanism in composite containing 10 vol.%B{sub 4}C. Moreover, it was shown that increasing B{sub 4}C content increases the wear resistance by 3 times under a load of 20 N and 10 times under a load of 10 N compared to CNTs-reinforced composite. surface roughness of the composite containing 5 vol.%CNT has shown to be more than other samples. The results of creep test showed that adding carbon nanotubes increases creep rate of Al 5083 alloy; however, adding B{sub 4}C decreases its creep rate. - Highlights: • Al 5083/(CNTs + B{sub 4}C) hybrid composite was produced by powder metallurgy method. • Creep behavior, wear resistance, surface roughness, and Hardness of samples were investigated. • Addition of CNTs to Al 5083 matrix reduces alloy hardness, wear resistance and creep strength. • By addition of B{sub 4}C and composite hybridization, creep strength and wear resistance increased. • Surface roughness of Al-5 vol.%CNT has shown to be more than other samples.

  16. Hybrid Shipboard Microgrids: System Architectures and Energy Management Aspects

    DEFF Research Database (Denmark)

    Othman @ Marzuki, Muzaidi Bin; Anvari-Moghaddam, Amjad; Guerrero, Josep M.

    2017-01-01

    such as renewables (e.g., solar PV, wind power) and conventionals (e.g., diesel engines) as well as energy storage systems (ESSs) such as batteries, fuel cells and flywheels. To optimally manage different energy sources in a shipboard microgrid while meeting different technical/environmental constraints......Strict regulation on emissions of air pollutants imposed by the maritime authorities has led to the introduction of hybrid microgrids to the shipboard power systems (SPSs) which acts toward energy efficient ships with less pollution. A hybrid energy system can include different means of generation......, it is necessary to set up an energy management system. This paper provides an overview of hybrid shipboard microgrids and discusses different methods of power and energy management in such systems which are essential for control, monitoring and optimizing the overall system performance in various mission profiles....

  17. Hybrid Intrusion Detection System for DDoS Attacks

    Directory of Open Access Journals (Sweden)

    Özge Cepheli

    2016-01-01

    Full Text Available Distributed denial-of-service (DDoS attacks are one of the major threats and possibly the hardest security problem for today’s Internet. In this paper we propose a hybrid detection system, referred to as hybrid intrusion detection system (H-IDS, for detection of DDoS attacks. Our proposed detection system makes use of both anomaly-based and signature-based detection methods separately but in an integrated fashion and combines the outcomes of both detectors to enhance the overall detection accuracy. We apply two distinct datasets to our proposed system in order to test the detection performance of H-IDS and conclude that the proposed hybrid system gives better results than the systems based on nonhybrid detection.

  18. Energy-Efficient Building HVAC Control Using Hybrid System LBMPC

    CERN Document Server

    Aswani, Anil; Taneja, Jay; Krioukov, Andrew; Culler, David; Tomlin, Claire

    2012-01-01

    Improving the energy-efficiency of heating, ventilation, and air-conditioning (HVAC) systems has the potential to realize large economic and societal benefits. This paper concerns the system identification of a hybrid system model of a building-wide HVAC system and its subsequent control using a hybrid system formulation of learning-based model predictive control (LBMPC). Here, the learning refers to model updates to the hybrid system model that incorporate the heating effects due to occupancy, solar effects, outside air temperature (OAT), and equipment, in addition to integrator dynamics inherently present in low-level control. Though we make significant modeling simplifications, our corresponding controller that uses this model is able to experimentally achieve a large reduction in energy usage without any degradations in occupant comfort. It is in this way that we justify the modeling simplifications that we have made. We conclude by presenting results from experiments on our building HVAC testbed, which s...

  19. Use of hybrid renewable energy systems for small communities

    Directory of Open Access Journals (Sweden)

    Bandoc Georgeta

    2016-01-01

    Full Text Available The purpose of this article is to present how the sizing of a hybrid renewable energy system is done for a community of three hundred and five households located in a Delta, starting from the optimization of hybrid energy system for a single household. The methodology used in solving this problem is based on multiple options. The first option consists in determined energy needs, maximum power consumption in cold season and in adapting the solution for the production of electricity by a hybrid plant. The second option consists of energy needs resulted in average consumption of electricity in warm season and in adapting the solution for the production of electricity from a hybrid plant. In conjunction with the demand for electricity for the entire community one will get energy demand by aggregating household level (kWh/household. The novelty of this approach lies in the method used by these hybrid systems for obtaining electricity in small communities, isolated from this case study. Based on the results obtained the method can be expanded the implementation of these projects that use hybrid renewable energy systems.

  20. Split-gene system for hybrid wheat seed production.

    Science.gov (United States)

    Kempe, Katja; Rubtsova, Myroslava; Gils, Mario

    2014-06-24

    Hybrid wheat plants are superior in yield and growth characteristics compared with their homozygous parents. The commercial production of wheat hybrids is difficult because of the inbreeding nature of wheat and the lack of a practical fertility control that enforces outcrossing. We describe a hybrid wheat system that relies on the expression of a phytotoxic barnase and provides for male sterility. The barnase coding information is divided and distributed at two loci that are located on allelic positions of the host chromosome and are therefore "linked in repulsion." Functional complementation of the loci is achieved through coexpression of the barnase fragments and intein-mediated ligation of the barnase protein fragments. This system allows for growth and maintenance of male-sterile female crossing partners, whereas the hybrids are fertile. The technology does not require fertility restorers and is based solely on the genetic modification of the female crossing partner.

  1. Hybrid Communication System Based on OFDM

    Directory of Open Access Journals (Sweden)

    2013-11-01

    Full Text Available A Hybrid architecture between terrestrial and satellite networks based on Orthogonal Frequency Division Multiplexing (OFDM is employed here. In hybrid architecture, the users will be able to avail the services through the terrestrial networks as well as the satellite networks. The users located in urban areas will be served by the existing terrestrial mobile networks and similarly the one located in rural areas will be provided services through the satellite networks. The technique which is used to achieve this objective is called Pre-FFT adaptive beamforming also called time domain beamforming. When the data is received at the satellite end, the Pre-FFT adaptive beamforming extracts the desired user data from the interferer user by applying the complex weights to the received symbol. The weight for the next symbol is then updated by Least Mean Square (LMS algorithm and then is applied to it. This process is carried out till all the desired user data is extracted.

  2. Analysis of Hybrid-Electric Propulsion System Designs for Small Unmanned Aircraft Systems

    Science.gov (United States)

    2010-03-01

    arrival of the Insight, nearly every major automotive manufacturer has released its own hybrid model. The Toyota Prius , released to the US in 2001, has...dominated the hybrid marketplace with US sales topping 1,000,000 in March 2009.17 The Prius features a power-split hybrid system enabling use of an

  3. Rapid Global Calibration Technology for Hybrid Visual Inspection System.

    Science.gov (United States)

    Liu, Tao; Yin, Shibin; Guo, Yin; Zhu, Jigui

    2017-06-19

    Vision-based methods for product quality inspection are playing an increasingly important role in modern industries for their good performance and high efficiency. A hybrid visual inspection system, which consists of an industrial robot with a flexible sensor and several stationary sensors, has been widely applied in mass production, especially in automobile manufacturing. In this paper, a rapid global calibration method for the hybrid visual inspection system is proposed. Global calibration of a flexible sensor is performed first based on the robot kinematic. Then, with the aid of the calibrated flexible sensor, stationary sensors are calibrated globally one by one based on homography. Only a standard sphere and an auxiliary target with a 2D planar pattern are applied during the system global calibration, and the calibration process can be easily re-performed during the system's periodical maintenance. An error compensation method is proposed for the hybrid inspection system, and the final accuracy of the hybrid system is evaluated with the deviation and correlation coefficient between the measured results of the hybrid system and Coordinate Measuring Machine (CMM). An accuracy verification experiment shows that deviation of over 95% of featured points are less than ±0.3 mm, and the correlation coefficients of over 85% of points are larger than 0.7.

  4. Towards a General Theory of Stochastic Hybrid Systems

    OpenAIRE

    Bujorianu, L.M.; Lygeros, J.; Bujorianu, M. C.

    2008-01-01

    In this paper we set up a mathematical structure, called Markov string, to obtaining a very general class of models for stochastic hybrid systems. Markov Strings are, in fact, a class of Markov processes, obtained by a mixing mechanism of stochastic processes, introduced by Meyer. We prove that Markov strings are strong Markov processes with the cadlag property. We then show how a very general class of stochastic hybrid processes can be embedded in the framework of Markov strings. This class,...

  5. Hybrid Recommendation System Memanfaatkan Penggalian Frequent Itemset dan Perbandingan Keyword

    OpenAIRE

    Suka Parwita, Wayan Gede; Winarko, Edi

    2015-01-01

    AbstrakRecommendation system sering dibangun dengan memanfaatkan data peringkat item dan data identitas pengguna. Data peringkat item merupakan data yang langka pada sistem yang baru dibangun. Sedangkan, pemberian data identitas pada recommendation system dapat menimbulkan kekhawatiran penyalahgunaan data identitas.Hybrid recommendation system memanfaatkan algoritma penggalian frequent itemset dan perbandingan keyword dapat memberikan daftar rekomendasi tanpa menggunakan data identitas penggu...

  6. Hybrid systems: a real-time interface to control engineering

    DEFF Research Database (Denmark)

    Eriksen, Thomas Juul; Heilmann, Søren; Holdgaard, Michael

    1996-01-01

    are usually investigated by control engineers that base their work on the theory of dynamic systems. The mathematical tool for this work is thus mathematical analysis, in particular the theory of differential equations. The paper gives an introduction to a general hybrid systems model for definition of system...

  7. Generalization of Dielectric-Dependent Hybrid Functionals to Finite Systems

    Science.gov (United States)

    Brawand, Nicholas P.; Vörös, Márton; Govoni, Marco; Galli, Giulia

    2016-10-01

    The accurate prediction of electronic and optical properties of molecules and solids is a persistent challenge for methods based on density functional theory. We propose a generalization of dielectric-dependent hybrid functionals to finite systems where the definition of the mixing fraction of exact and semilocal exchange is physically motivated, nonempirical, and system dependent. The proposed functional yields ionization potentials, and fundamental and optical gaps of many, diverse molecular systems in excellent agreement with experiments, including organic and inorganic molecules and semiconducting nanocrystals. We further demonstrate that this hybrid functional gives the correct alignment between energy levels of the exemplary TTF-TCNQ donor-acceptor system.

  8. Impulsive and hybrid dynamical systems stability, dissipativity, and control

    CERN Document Server

    Haddad, Wassim M; Nersesov, Sergey G

    2014-01-01

    This book develops a general analysis and synthesis framework for impulsive and hybrid dynamical systems. Such a framework is imperative for modern complex engineering systems that involve interacting continuous-time and discrete-time dynamics with multiple modes of operation that place stringent demands on controller design and require implementation of increasing complexity--whether advanced high-performance tactical fighter aircraft and space vehicles, variable-cycle gas turbine engines, or air and ground transportation systems. Impulsive and Hybrid Dynamical Systems goes beyond similar

  9. Stiffness and Strength of Fiber Reinforced Polymer Composite Bridge Deck Systems

    OpenAIRE

    2002-01-01

    This research investigates two principal characteristics that are of primary importance in Fiber Reinforced Polymer (FRP) bridge deck applications: STIFFNESS and STRENGTH. The research was undertaken by investigating the stiffness and strength characteristics of the multi-cellular FRP bridge deck systems consisting of pultruded FRP shapes. A systematic analysis procedure was developed for the stiffness analysis of multi-cellular FRP deck systems. This procedure uses the Method of Elasti...

  10. Non-contact characterization of hybrid aluminium/carbon-fibre-reinforced plastic sheets using multi-frequency eddy-current sensors

    Science.gov (United States)

    Yin, W.; Li, X.; Withers, P. J.; Peyton, A. J.

    2010-10-01

    The characterization of hybrid aluminium/carbon-fibre-reinforced plastic (CFRP) sheets using multi-frequency eddy-current sensors is presented in this paper. Both air-cored circular sensors and highly directional ferrite-cored sensors are designed for bulk conductivity measurements and directionality characterization. An analytical model describing the interaction of the circular sensors with the hybrid planar structure is developed. Finite element (FE) models that take into account the anisotropicity of CFRP have also been proposed. Both models are in good agreement with experimental results. The features of the sensor output signals are analysed and explained. It is proved that an anisotropic model (tensor expression for conductivity) is appropriate for the CFRP materials under investigation. A formula to link the bulk conductivity with the conductivity tensor is proposed and verified. Lift-off effects are also discussed. It is believed that this is amongst the first published reports of using eddy-current techniques for characterizing the hybrid aluminium/CFRP material.

  11. Rapid Global Calibration Technology for Hybrid Visual Inspection System

    Directory of Open Access Journals (Sweden)

    Tao Liu

    2017-06-01

    Full Text Available Vision-based methods for product quality inspection are playing an increasingly important role in modern industries for their good performance and high efficiency. A hybrid visual inspection system, which consists of an industrial robot with a flexible sensor and several stationary sensors, has been widely applied in mass production, especially in automobile manufacturing. In this paper, a rapid global calibration method for the hybrid visual inspection system is proposed. Global calibration of a flexible sensor is performed first based on the robot kinematic. Then, with the aid of the calibrated flexible sensor, stationary sensors are calibrated globally one by one based on homography. Only a standard sphere and an auxiliary target with a 2D planar pattern are applied during the system global calibration, and the calibration process can be easily re-performed during the system’s periodical maintenance. An error compensation method is proposed for the hybrid inspection system, and the final accuracy of the hybrid system is evaluated with the deviation and correlation coefficient between the measured results of the hybrid system and Coordinate Measuring Machine (CMM. An accuracy verification experiment shows that deviation of over 95% of featured points are less than ±0.3 mm, and the correlation coefficients of over 85% of points are larger than 0.7.

  12. Agnostic System Identification for Model-Based Reinforcement Learning

    CERN Document Server

    Ross, Stephane

    2012-01-01

    A fundamental problem in control is to learn a model of a system from observations that is useful for controller synthesis. To provide good performance guarantees, existing methods must assume that the real system is in the class of models considered during learning. We present an iterative method with strong guarantees even in the agnostic case where the system is not in the class. In particular, we show that any no-regret online learning algorithm can be used to obtain a near-optimal policy, provided some model achieves low training error and access to a good exploration distribution. Our approach applies to both discrete and continuous domains. We demonstrate its efficacy and scalability on a challenging helicopter domain from the literature.

  13. Evaluation of Mechanical Properties and Morphological Studies of Rice Husk (Treated/Untreated)-CaCO3 Reinforced Epoxy Hybrid Composites

    Science.gov (United States)

    Verma, Deepak; Joshi, Garvit; Gupta, Ayush

    2016-10-01

    Natural fiber reinforced composites are a very popular area of research because of the easy availability and biodegradability of these fibers. The manufacturing of natural fiber composite is done by reinforcing fibers in the particulate form, fiber form or in woven mat form. Natural fiber composites also utilize industrial wastes as a secondary reinforcements like fly ash, sludge etc. By keeping all these point of views in the present investigation the effect of rice husk flour (chemically treated/untreated) and micro sized calcium carbonate with epoxy resin have been evaluated. The diameter of rice husk flour was maintained at 600 µm through mechanical sieving machine. The husk flour was chemically treated with NaOH (5 % w/v). Mechanical properties like hardness, flexural impact and compression strength were evaluated and found to be superior in modified or chemically treated flour as compared to unmodified or untreated flour reinforced composites. Scanning electron microscopy (SEM) study was also undertaken for the developed composites. SEM study shows the distribution of the rice husk flour and calcium carbonate over the matrix.

  14. INVESTIGATION OF NON ERODING NOZZLE MATERIALS FOR OPTIMIZED COATED HYBRID LEADING EDGE DESIGNS FOR REUSABLE LAUNCH VEHICALS WITH LEADING EDGE RADII OF 0.03? TO 1? AND TEMPERATURES NEAR 4000?F Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Effort explores using innovative hybrid reinforced carbon-carbon, refractory ceramics, super alloys and composite materials as thermal protection system specifically...

  15. Multi-Agent System based Event-Triggered Hybrid Controls for High-Security Hybrid Energy Generation Systems

    DEFF Research Database (Denmark)

    Dou, Chun-Xia; Yue, Dong; Guerrero, Josep M.

    2017-01-01

    This paper proposes multi-agent system based event- triggered hybrid controls for guaranteeing energy supply of a hybrid energy generation system with high security. First, a mul-ti-agent system is constituted by an upper-level central coordi-nated control agent combined with several lower...... switching control, distributed dynamic regulation and coordinated switching con-trol are designed fully dependent on the hybrid behaviors of all distributed energy resources and the logical relationships be-tween them, and interact with each other by means of the mul-ti-agent system to form hierarchical......-level unit agents. Each lower-level unit agent is responsible for dealing with internal switching control and distributed dynamic regula-tion for its unit system. The upper-level agent implements coor-dinated switching control to guarantee the power supply of over-all system with high security. The internal...

  16. 基于强化学习的多Agent系统%The Multi-Agent System Based on Reinforcement Learning

    Institute of Scientific and Technical Information of China (English)

    唐文彬; 朱淼良

    2003-01-01

    Reinforcement learning allows agent that has no knowledge of an environment to cooperate more efficacious each other. This paper presents an approach for developing multi-agent reinforcement learning systems based on equation principle. The experiment shows agent can produces the desired behavior under all kinds of situation.

  17. Improving Multi agent Systems Based on Reinforcement Learning and Case Base Reasoning

    Directory of Open Access Journals (Sweden)

    Sara Esfandiari

    2012-01-01

    Full Text Available In this paper, a new algorithm based on case base reasoning and reinforcement learning is proposed to increase the rate convergence of the Selfish Q-Learning algorithms in multi-agent systems. In the propose method, we investigate how making improved action selection in reinforcement learning (RL algorithm. In the proposed method, the new combined model using case base reasoning systems and a new optimized function has been proposed to select the action, which has led to an increase in algorithms based on Selfish Q-learning. The algorithm mentioned has been used for solving the problem of cooperative Markovs games as one of the models of Markov based multi-agent systems. The results of experiments on two ground have shown that the proposed algorithm perform better than the existing algorithms in terms of speed and accuracy of reaching the optimal policy.

  18. Modelling and analysis of real-time and hybrid systems

    Energy Technology Data Exchange (ETDEWEB)

    Olivero, A.

    1994-09-29

    This work deals with the modelling and analysis of real-time and hybrid systems. We first present the timed-graphs as model for the real-time systems and we recall the basic notions of the analysis of real-time systems. We describe the temporal properties on the timed-graphs using TCTL formulas. We consider two methods for property verification: in one hand we study the symbolic model-checking (based on backward analysis) and in the other hand we propose a verification method derived of the construction of the simulation graph (based on forward analysis). Both methods have been implemented within the KRONOS verification tool. Their application for the automatic verification on several real-time systems confirms the practical interest of our approach. In a second part we study the hybrid systems, systems combining discrete components with continuous ones. As in the general case the analysis of this king of systems is not decidable, we identify two sub-classes of hybrid systems and we give a construction based method for the generation of a timed-graph from an element into the sub-classes. We prove that in one case the timed-graph obtained is bi-similar with the considered system and that there exists a simulation in the other case. These relationships allow the application of the described technics on the hybrid systems into the defined sub-classes. (authors). 60 refs., 43 figs., 8 tabs., 2 annexes.

  19. INEXPENSIVE, OFF THE SHELF HYBRID MICROWAVE SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Walters, T; Paul Burket, P; John Scogin, J

    2007-06-21

    A hybrid-heating microwave oven provides the energy to heat small 10-gram samples of spent metal tritide storage bed material to release tenaciously held decay product {sup 3}He. Complete mass balance procedures require direct measurement of added or produced gases on a tritide bed, and over 1100 C is necessary to release deep trapped {sup 3}He. The decomposition of non-radioactive CaCO{sub 3} and the quantitative measurement of CO{sub 2} within 3% of stoichiometry demonstrate the capabilities of the apparatus to capture generated (released) gases.

  20. Hybrid simulation theory for a classical nonlinear dynamical system

    Science.gov (United States)

    Drazin, Paul L.; Govindjee, Sanjay

    2017-03-01

    Hybrid simulation is an experimental and computational technique which allows one to study the time evolution of a system by physically testing a subset of it while the remainder is represented by a numerical model that is attached to the physical portion via sensors and actuators. The technique allows one to study large or complicated mechanical systems while only requiring a subset of the complete system to be present in the laboratory. This results in vast cost savings as well as the ability to study systems that simply can not be tested due to scale. However, the errors that arise from splitting the system in two requires careful attention, if a valid simulation is to be guaranteed. To date, efforts to understand the theoretical limitations of hybrid simulation have been restricted to linear dynamical systems. In this work we consider the behavior of hybrid simulation when applied to nonlinear dynamical systems. As a model problem, we focus on the damped, harmonically-driven nonlinear pendulum. This system offers complex nonlinear characteristics, in particular periodic and chaotic motions. We are able to show that the application of hybrid simulation to nonlinear systems requires a careful understanding of what one expects from such an experiment. In particular, when system response is chaotic we advocate the need for the use of multiple metrics to characterize the difference between two chaotic systems via Lyapunov exponents and Lyapunov dimensions, as well as correlation exponents. When system response is periodic we advocate the use of L2 norms. Further, we are able to show that hybrid simulation can falsely predict chaotic or periodic response when the true system has the opposite characteristic. In certain cases, we are able to show that control system parameters can mitigate this issue.

  1. Viability of Hybrid Systems A Controllability Operator Approach

    CERN Document Server

    Labinaz, G

    2012-01-01

    The problem of viability of hybrid systems is considered in this work. A model for a hybrid system is developed including a means of including three forms of uncertainty: transition dynamics, structural uncertainty, and parametric uncertainty. A computational basis for viability of hybrid systems is developed and applied to three control law classes. An approach is developed for robust viability based on two extensions of the controllability operator. The three-tank example is examined for both the viability problem and robust viability problem. The theory is applied through simulation to an active magnetic bearing system and to a batch polymerization process showing that viability can be satisfied in practice. The problem of viable attainability is examined based on the controllability operator approach introduced by Nerode and colleagues. Lastly, properties of the controllability operator are presented.

  2. Hybrid energy system cost analysis: San Nicolas Island, California

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, T.L.; McKenna, E.

    1996-07-01

    This report analyzes the local wind resource and evaluates the costs and benefits of supplementing the current diesel-powered energy system on San Nicolas Island, California (SNI), with wind turbines. In Section 2.0 the SNI site, naval operations, and current energy system are described, as are the data collection and analysis procedures. Section 3.0 summarizes the wind resource data and analyses that were presented in NREL/TP 442-20231. Sections 4.0 and 5.0 present the conceptual design and cost analysis of a hybrid wind and diesel energy system on SNI, with conclusions following in Section 6. Appendix A presents summary pages of the hybrid system spreadsheet model, and Appendix B contains input and output files for the HYBRID2 program.

  3. Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Faress Rahman; Nguyen Minh

    2004-01-04

    This report summarizes the work performed by Hybrid Power Generation Systems, LLC (HPGS) during the July 2003 to December 2003 reporting period under Cooperative Agreement DE-FC26-01NT40779 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation''. The main objective of this project is to develop and demonstrate the feasibility of a highly efficient hybrid system integrating a planar Solid Oxide Fuel Cell (SOFC) and a micro-turbine. In addition, an activity included in this program focuses on the development of an integrated coal gasification fuel cell system concept based on planar SOFC technology. Also, another activity included in this program focuses on the development of SOFC scale up strategies.

  4. A hybrid continuous-wave terahertz imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Dolganova, Irina N., E-mail: in.dolganova@gmail.com; Zaytsev, Kirill I., E-mail: kirzay@gmail.ru; Metelkina, Anna A.; Karasik, Valeriy E.; Yurchenko, Stanislav O., E-mail: st.yurchenko@mail.ru [Bauman Moscow State Technical University, 2nd Baumanskaya str. 5, Moscow 105005 (Russian Federation)

    2015-11-15

    A hybrid (active-passive mode) terahertz (THz) imaging system and an algorithm for imaging synthesis are proposed to enhance the THz image quality. The concept of image contrast is used to compare active and passive THz imaging. Combining the measurement of the self-emitted radiation of the object with the back-scattered source radiation measurement, it becomes possible to use the THz image to retrieve maximum information about the object. The experimental results confirm the advantages of hybrid THz imaging systems, which can be generalized for a wide range of applications in the material sciences, chemical physics, bio-systems, etc.

  5. Benefits of solar/fossil hybrid gas turbine systems

    Science.gov (United States)

    Bloomfield, H. S.

    1979-01-01

    The potential benefits of solar/fossil hybrid gas turbine power systems were assessed. Both retrofit and new systems were considered from the aspects of cost of electricity, fuel conservation, operational mode, technology requirements, and fuels flexibility. Hybrid retrofit (repowering) of existing combustion (simple Brayton cycle) turbines can provide near-term fuel savings and solar experience, while new and advanced recuperated or combined cycle systems may be an attractive fuel saving and economically competitive vehicle to transition from today's gas and oil-fired powerplants to other more abundant fuels.

  6. 15th International conference on Hybrid Intelligent Systems

    CERN Document Server

    Han, Sang; Al-Sharhan, Salah; Liu, Hongbo

    2016-01-01

    This book is devoted to the hybridization of intelligent systems which is a promising research field of modern computational intelligence concerned with the development of the next generation of intelligent systems. This Volume contains the papers presented in the Fifteenth International conference on Hybrid Intelligent Systems (HIS 2015) held in Seoul, South Korea during November 16-18, 2015. The 26 papers presented in this Volume were carefully reviewed and selected from 90 paper submissions. The Volume will be a valuable reference to researchers, students and practitioners in the computational intelligence field.

  7. Hybrid Collaborative Stereo Vision System for Mobile Robots Formation

    Directory of Open Access Journals (Sweden)

    Flavio Roberti

    2010-02-01

    Full Text Available This paper presents the use of a hybrid collaborative stereo vision system (3D-distributed visual sensing using different kinds of vision cameras for the autonomous navigation of a wheeled robot team. It is proposed a triangulation-based method for the 3D-posture computation of an unknown object by considering the collaborative hybrid stereo vision system, and this way to steer the robot team to a desired position relative to such object while maintaining a desired robot formation. Experimental results with real mobile robots are included to validate the proposed vision system.

  8. A Wireless Passive Sensing System for Displacement/Strain Measurement in Reinforced Concrete Members

    Science.gov (United States)

    Ozbey, Burak; Erturk, Vakur B.; Demir, Hilmi Volkan; Altintas, Ayhan; Kurc, Ozgur

    2016-01-01

    In this study, we show a wireless passive sensing system embedded in a reinforced concrete member successfully being employed for the measurement of relative displacement and strain in a simply supported beam experiment. The system utilizes electromagnetic coupling between the transceiver antenna located outside the beam, and the sensing probes placed on the reinforcing bar (rebar) surface inside the beam. The probes were designed in the form of a nested split-ring resonator, a metamaterial-based structure chosen for its compact size and high sensitivity/resolution, which is at µm/microstrains level. Experiments were performed in both the elastic and plastic deformation cases of steel rebars, and the sensing system was demonstrated to acquire telemetric data in both cases. The wireless measurement results from multiple probes are compared with the data obtained from the strain gages, and an excellent agreement is observed. A discrete time measurement where the system records data at different force levels is also shown. Practical issues regarding the placement of the sensors and accurate recording of data are discussed. The proposed sensing technology is demonstrated to be a good candidate for wireless structural health monitoring (SHM) of reinforced concrete members by its high sensitivity and wide dynamic range. PMID:27070615

  9. A Wireless Passive Sensing System for Displacement/Strain Measurement in Reinforced Concrete Members

    Directory of Open Access Journals (Sweden)

    Burak Ozbey

    2016-04-01

    Full Text Available In this study, we show a wireless passive sensing system embedded in a reinforced concrete member successfully being employed for the measurement of relative displacement and strain in a simply supported beam experiment. The system utilizes electromagnetic coupling between the transceiver antenna located outside the beam, and the sensing probes placed on the reinforcing bar (rebar surface inside the beam. The probes were designed in the form of a nested split-ring resonator, a metamaterial-based structure chosen for its compact size and high sensitivity/resolution, which is at µm/microstrains level. Experiments were performed in both the elastic and plastic deformation cases of steel rebars, and the sensing system was demonstrated to acquire telemetric data in both cases. The wireless measurement results from multiple probes are compared with the data obtained from the strain gages, and an excellent agreement is observed. A discrete time measurement where the system records data at different force levels is also shown. Practical issues regarding the placement of the sensors and accurate recording of data are discussed. The proposed sensing technology is demonstrated to be a good candidate for wireless structural health monitoring (SHM of reinforced concrete members by its high sensitivity and wide dynamic range.

  10. A Wireless Passive Sensing System for Displacement/Strain Measurement in Reinforced Concrete Members.

    Science.gov (United States)

    Ozbey, Burak; Erturk, Vakur B; Demir, Hilmi Volkan; Altintas, Ayhan; Kurc, Ozgur

    2016-04-08

    In this study, we show a wireless passive sensing system embedded in a reinforced concrete member successfully being employed for the measurement of relative displacement and strain in a simply supported beam experiment. The system utilizes electromagnetic coupling between the transceiver antenna located outside the beam, and the sensing probes placed on the reinforcing bar (rebar) surface inside the beam. The probes were designed in the form of a nested split-ring resonator, a metamaterial-based structure chosen for its compact size and high sensitivity/resolution, which is at µm/microstrains level. Experiments were performed in both the elastic and plastic deformation cases of steel rebars, and the sensing system was demonstrated to acquire telemetric data in both cases. The wireless measurement results from multiple probes are compared with the data obtained from the strain gages, and an excellent agreement is observed. A discrete time measurement where the system records data at different force levels is also shown. Practical issues regarding the placement of the sensors and accurate recording of data are discussed. The proposed sensing technology is demonstrated to be a good candidate for wireless structural health monitoring (SHM) of reinforced concrete members by its high sensitivity and wide dynamic range.

  11. Load flow computations in hybrid transmission - distributed power systems

    NARCIS (Netherlands)

    Wobbes, E.D.; Lahaye, D.J.P.

    2013-01-01

    We interconnect transmission and distribution power systems and perform load flow computations in the hybrid network. In the largest example we managed to build, fifty copies of a distribution network consisting of fifteen nodes is connected to the UCTE study model, resulting in a system consisting

  12. Study of optimal control problems for hybrid dynamical systems

    Institute of Scientific and Technical Information of China (English)

    Gao Rui; Wang Lei; Wang Yuzhen

    2006-01-01

    From the viewpoint of continuous systems, optimal control problem is proposed for a class of controlled Hybrid dynamical systems. Then a mathematical method- HDS minimum principle is put forward, which can solve the above problem. The HDS minimum principle is proved by means of Ekeland's variational principle.

  13. Rates of reinforcement and measures of compliance in free and protected contact elephant management systems.

    Science.gov (United States)

    Wilson, Megan L; Perdue, Bonnie M; Bloomsmith, Mollie A; Maple, Terry L

    2015-01-01

    Protected contact is an alternative to traditional captive elephant training techniques that emerged as a result of concerns for animal welfare and personnel safety. The present study documented the behavior of elephants and their animal care professionals to determine rates of reinforcement and measures of compliance under two handling systems. Behavioral data were collected from animal care professionals and elephants during the elephants' baths in both free contact (FC) and protected contact (PC). Positive reinforcement, in the form of food, was delivered, on average, nearly eight times more frequently in the PC condition. Further, the mean rate at which the animal care professionals used the ankus in the FC condition as negative reinforcement was similar to the mean rate at which they provided positive reinforcement to the elephants in the FC condition. Latencies between verbal commands and the elephants' behaviors demonstrated an inconsistent pattern, but were generally longer in the PC condition. The mean percent of "refusals" by the elephants was higher for most behaviors across elephants in the PC condition. The findings suggest that animal care professionals did not heavily rely on positive reinforcement in the FC condition to elicit desired behaviors from the elephants, but this was the case in the PC condition. We propose that longer latencies and higher mean percent of refusals by the elephants may indicate that they were exercising choice or control over their environment, which has been associated with improved well-being. Additional studies of this kind are needed to enable other institutions to make informed decisions about elephant management and welfare.

  14. Dimension Reduction Near Periodic Orbits of Hybrid Systems

    CERN Document Server

    Burden, Samuel; Sastry, S Shankar

    2011-01-01

    When the Poincar\\'{e} map associated with a periodic orbit of a hybrid dynamical system has constant-rank iterates, we demonstrate the existence of a constant-dimensional invariant subsystem near the orbit which attracts all nearby trajectories in finite time. This result shows that the long-term behavior of a hybrid model with a large number of degrees-of-freedom may be governed by a low-dimensional smooth dynamical system. The appearance of such simplified models enables the translation of analytical tools from smooth systems-such as Floquet theory-to the hybrid setting and provides a bridge between the efforts of biologists and engineers studying legged locomotion.

  15. Effect of water absorption on the mechanical properties of nanoclay filled recycled cellulose fibre reinforced epoxy hybrid nanocomposites

    KAUST Repository

    Alamri, H.

    2013-01-01

    Recycled cellulose fibre (RCF) reinforced epoxy/clay nanocomposites were successfully synthesized with different weight percentages (0%, 1%, 3% and 5%) of organoclay platelets (30B). The objective of this study was to investigate the effect of water absorption on the physical and mechanical properties of the RCF reinforced epoxy/clay nanocomposites. TEM images indicated a well-intercalated structure of nanoclay/epoxy matrix with some exfoliated regions. Water absorption was found to decrease as the clay content increased. The flexural strength, flexural modulus and fracture toughness significantly decreased as a result of water absorption. However, the properties of impact strength and impact toughness were found to increase after exposing to water. The addition of nanoclay slightly minimized the effect of moisture on the mechanical properties. SEM images showed that water absorption severely damaged the cellulose fibres and the bonding at fibres-matrix interfaces in wet composites. © 2012 Elsevier Ltd. All rights reserved.

  16. Hierarchical modeling and control of hybrid systems with two layers; Hierarchische Modellierung und Regelung hybrider Systeme auf zwei Ebenen

    Energy Technology Data Exchange (ETDEWEB)

    Stursberg, Olaf; Paschedag, Tina; Rungger, Matthias; Ding, Hao [Kassel Univ. (Germany). Fachgebiet Regelungs- und Systemtheorie

    2010-08-15

    While hybrid dynamic models are, to a certain degree, established for modeling systems with heterogeneous dynamics, most approaches for design and analysis of hybrid systems are restricted to monolithic models without hierarchy. This contribution first shows, how modular hybrid systems with two layers of decision, as appropriate for representing manufacturing systems for example, can be modeled systematically. The second part proposes a technique for fixing discrete inputs (for coordinating control) and continuous inputs (for embedded continuous controllers) in combination. The method uses a graph-based search on the upper decision layer, while principles of predictive control are used on the lower layer. The procedure of modeling and control is illustrated for a manufacturing process. (orig.)

  17. Novel Electrospun Polylactic Acid Nanocomposite Fiber Mats with Hybrid Graphene Oxide and Nanohydroxyapatite Reinforcements Having Enhanced Biocompatibility

    OpenAIRE

    Chen Liu; Hoi Man Wong; Kelvin Wai Kwok Yeung; Sie Chin Tjong

    2016-01-01

    Graphene oxide (GO) and a nanohydroxyapatite rod (nHA) of good biocompatibility were incorporated into polylactic acid (PLA) through electrospinning to form nanocomposite fiber scaffolds for bone tissue engineering applications. The preparation, morphological, mechanical and thermal properties, as well as biocompatibility of electrospun PLA scaffolds reinforced with GO and/or nHA were investigated. Electron microscopic examination and image analysis showed that GO and nHA nanofillers refine t...

  18. Photovoltaic/diesel hybrid systems: The design process

    Science.gov (United States)

    Jones, G. J.; Chapman, R. N.

    A photovoltaic/storage system by itself may be uneconomical for stand-alone applications with large energy demands. However, by combining the PV system with a back-up energy source, such as a diesel, gasoline, or propane/thermoelectric generator, system economics can be improved. Such PV/fossil hybrid systems are being used, but their design has required detailed modeling to determine the optimal mix of photovoltaics and back-up energy. Recent data on diesel field reliability and a new design technique for stand-alone systems have overcome this problem. The approach provides the means for sizing the photovoltaic system to obtain a near optimal hybrid system, with about a 90% savings in back-up fuel costs. System economics are determined by comparing PV capital cost to the present value of the displaced diesel operation and maintenance costs.

  19. Syntheses of silsesquioxane (POSS)-based inorganic/organic hybrid and the application in reinforcement for an epoxy resin.

    Science.gov (United States)

    Ni, Caihua; Ni, Guifeng; Zhang, Liping; Mi, Jiaquan; Yao, Bolong; Zhu, Changping

    2011-10-01

    A new inorganic/organic hybrid material containing silsesquioxane was prepared by the reaction of caged octa (aminopropyl silsesquioxane) (POSS-NH(2)) with n-butyl glycidyl ether (nBGE) and 1,4-butanediol diglycidyl ether (BDGE). The copolymers of POSS, nBGE, and BDGE could be obtained with varied feed ratio of POSS-NH(2), nBGE, and BDGE in the preparation. The hybrid material was added into an epoxy resin (E51) for enhancing the toughening and thermal properties of the epoxy resin. The results showed that the toughening and the thermal properties of the cured epoxy resin were greatly improved by the addition of the hybrid. The enhancement was ascribed to nano-scale effect of the POSS structure and the formation of anchor structure in the cured network. The investigation of kinetics for the curing process of the hybrid-modified epoxy resin revealed that two kinds of curing reactions occurred in different temperature ranges. They were attributed to the reactions between amino groups of the curing agent with epoxy groups of E51 and with residue epoxy groups in the hybrid. The reacting activation energies were calculated based on Kissinger's and Flynn-Wall-Ozawa's methods, respectively.

  20. Radio frequency shielding behaviour of silane treated Fe2O3/E-glass fibre reinforced epoxy hybrid composite

    Science.gov (United States)

    Arun prakash, V. R.; Rajadurai, A.

    2016-10-01

    In this work, radio frequency shielding behaviour of polymer (epoxy) matrixes composed of E-glass fibres and Fe2O3 fillers have been studied. The principal aim of this project is to prepare suitable shielding material for RFID application. When RFID unit is pasted on a metal plate without shielding material, the sensing distance is reduced, resulting in a less than useful RFID system. To improve RF shielding of epoxy, fibres and fillers were utilized. Magnetic behaviour of epoxy polymer composites was measured by hysteresis graphs (B-H) followed by radio frequency identifier setup. Fe2O3 particles of sizes 800, 200 and 100 nm and E-glass fibre woven mat of 600 g/m2 were used to make composites. Particle sizes of 800 nm and 200 nm were prepared by high-energy ball milling, whereas particles of 100 nm were prepared by sol-gel method. To enhance better dispersion of particles within the epoxy matrix, a surface modification process was carried out on fillers by an amino functional coupling agent called 3-Aminopropyltrimethoxysilane (APTMS). Crystalline and functional groups of siliconized Fe2O3 particles were characterized by XRD and FTIR spectroscopy analysis. Variable quantity of E-glass fibre (25, 35, and 45 vol%) was laid down along with 0.5 and 1.0 vol% of 800, 200, and 100 nm size Fe2O3 particles into the matrix, to fabricate the hybrid composites. Scanning electron microscopy and transmission electron microscopy images reveal the shape and size of Fe2O3 particles for different milling times and particle dispersion in the epoxy matrix. The maximum improved sensing distance of 45.2, 39.4 and 43.5 % was observed for low-, high-, and ultra-high radio frequency identifier setup along with shielding composite consist of epoxy, 1 vol% 200 nm Fe2O3 particles and 45 vol% of E-glass fibre.

  1. Diagnosing Hybrid Systems: a Bayesian Model Selection Approach

    Science.gov (United States)

    McIlraith, Sheila A.

    2005-01-01

    In this paper we examine the problem of monitoring and diagnosing noisy complex dynamical systems that are modeled as hybrid systems-models of continuous behavior, interleaved by discrete transitions. In particular, we examine continuous systems with embedded supervisory controllers that experience abrupt, partial or full failure of component devices. Building on our previous work in this area (MBCG99;MBCG00), our specific focus in this paper ins on the mathematical formulation of the hybrid monitoring and diagnosis task as a Bayesian model tracking algorithm. The nonlinear dynamics of many hybrid systems present challenges to probabilistic tracking. Further, probabilistic tracking of a system for the purposes of diagnosis is problematic because the models of the system corresponding to failure modes are numerous and generally very unlikely. To focus tracking on these unlikely models and to reduce the number of potential models under consideration, we exploit logic-based techniques for qualitative model-based diagnosis to conjecture a limited initial set of consistent candidate models. In this paper we discuss alternative tracking techniques that are relevant to different classes of hybrid systems, focusing specifically on a method for tracking multiple models of nonlinear behavior simultaneously using factored sampling and conditional density propagation. To illustrate and motivate the approach described in this paper we examine the problem of monitoring and diganosing NASA's Sprint AERCam, a small spherical robotic camera unit with 12 thrusters that enable both linear and rotational motion.

  2. Adaptive and Reliable Control Algorithm for Hybrid System Architecture

    Directory of Open Access Journals (Sweden)

    Osama Abdel Hakeem Abdel Sattar

    2012-01-01

    Full Text Available A stand-alone system is defined as an autonomous system that supplies electricity without being connected to the electric grid. Hybrid systems combined renewable energy source, that are never depleted (such solar (photovoltaic (PV, wind, hydroelectric, etc. , With other sources of energy, like Diesel. If these hybrid systems are optimally designed, they can be more cost effective and reliable than single systems. However, the design of hybrid systems is complex because of the uncertain renewable energy supplies, load demands and the non-linear characteristics of some components, so the design problem cannot be solved easily by classical optimisation methods. The use of heuristic techniques, such as the genetic algorithms, can give better results than classical methods. This paper presents to a hybrid system control algorithm and also dispatches strategy design in which wind is the primary energy resource with photovoltaic cells. The dimension of the design (max. load is 2000 kW and the sources is implemented as flow 1500 kw from wind, 500 kw from solar and diesel 2000 kw. The main task of the preposed algorithm is to take full advantage of the wind energy and solar energy when it is available and to minimize diesel fuel consumption.

  3. Hybrid Atom Electrostatic System for Satellite Geodesy

    Science.gov (United States)

    Zahzam, Nassim; Bidel, Yannick; Bresson, Alexandre; Huynh, Phuong-Anh; Liorzou, Françoise; Lebat, Vincent; Foulon, Bernard; Christophe, Bruno

    2017-04-01

    The subject of this poster comes within the framework of new concepts identification and development for future satellite gravity missions, in continuation of previously launched space missions CHAMP, GRACE, GOCE and ongoing and prospective studies like NGGM, GRACE 2 or E-GRASP. We were here more focused on the inertial sensors that complete the payload of such satellites. The clearly identified instruments for space accelerometry are based on the electrostatic technology developed for many years by ONERA and that offer a high level of performance and a high degree of maturity for space applications. On the other hand, a new generation of sensors based on cold atom interferometry (AI) is emerging and seems very promising in this context. These atomic instruments have already demonstrated on ground impressive results, especially with the development of state-of-the-art gravimeters, and should reach their full potential only in space, where the microgravity environment allows long interaction times. Each of these two types of instruments presents their own advantages which are, for the electrostatic sensors (ES), their demonstrated short term sensitivity and their high TRL, and for AI, amongst others, the absolute nature of the measurement and therefore no need for calibration processes. These two technologies seem in some aspects very complementary and a hybrid sensor bringing together all their assets could be the opportunity to take a big step in this context of gravity space missions. We present here the first experimental association on ground of an electrostatic accelerometer and an atomic accelerometer and underline the interest of calibrating the ES instrument with the AI. Some technical methods using the ES proof-mass as the Raman Mirror seem very promising to remove rotation effects of the satellite on the AI signal. We propose a roadmap to explore further in details and more rigorously this attractive hybridization scheme in order to assess its potential

  4. On the Mechanical Properties of Hybrid Aluminium 7075 Matrix Composite Material Reinforced with SiC and TiC Produced by Powder Metallurgy Method

    Directory of Open Access Journals (Sweden)

    S. Pradeep Devaneyan

    2017-01-01

    Full Text Available Metal matrix composites are widely used in components of various components of industrial equipment because of their superior material properties like high stiffness to weight ratio and high impact strength and fracture toughness while compared to the conventional material. Due to the concepts of high strength to low weight ratio, Al 7075 was extensively applied in aircraft engine and wings. Even if Al 7075 has higher hardness, higher strength, excellent wear resistance, and high-temperature corrosion protection, it is in need of further enhancement of properties for increasing its applicability. This paper presents the mechanical behavior of aluminium 7075 reinforced with Silicon Carbide (SiC and Titanium Carbide (TiC through powder metallurgy route. These specimens were produced by powder metallurgy method. The hybrid composite was made by Al 7075 alloy as the matrix with Silicon Carbide and Titanium Carbide as reinforcement. Silicon Carbide and Titanium Carbide are mixed in different weight ratio based on the design matrix formulated through a statistical tool, namely, Response Surface Methodology (RSM. Enhanced mechanical properties have been obtained with 90% of Al 7075, 4% of TiC, and 8% of SiC composition in the composite. Coefficient of friction appears to be more which has been determined by ring compression test.

  5. Comparison between hybrid renewable energy systems in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Hisham El Khashab

    2015-05-01

    This paper investigates RE sources applications at Yanbu, Saudi Arabia, besides a simulation using HOMER software to three proposed systems newly erected in Yanbu Industrial College Renewable Energy (RE lab. The lab represents a hybrid system, composed of PV, wind turbine, and Fuel cell systems. The cost of energy is compared in the three systems to have an actual estimation for RE in developing countries. The climatic variations at Yanbu that is located on the west coast of Saudi Arabia are considered.

  6. Optical-digital hybrid image search system in cloud environment

    Science.gov (United States)

    Ikeda, Kanami; Kodate, Kashiko; Watanabe, Eriko

    2016-09-01

    To improve the versatility and usability of optical correlators, we developed an optical-digital hybrid image search system consisting of digital servers and an optical correlator that can be used to perform image searches in the cloud environment via a web browser. This hybrid system employs a simple method to obtain correlation signals and has a distributed network design. The correlation signals are acquired by using an encoder timing signal generated by a rotating disk, and the distributed network design facilitates the replacement and combination of the digital correlation server and the optical correlator.

  7. Engine-driven hybrid air-conditioning system

    Institute of Scientific and Technical Information of China (English)

    Chaokui QIN; Hongmei LU; Xiong LIU; Gerhard SCHMITZ

    2009-01-01

    A hybrid air-conditioning system that com-bines an engine-driven chiller with desiccant dehumidifi-cation was configured and experimentally tested to provide reliable data for energy consumption and operation cost. The engine performance and the desiccant wheel perfor-mance were measured and a numeric model previously set up for dehumidification capacity prediction was validated. For a reference building, the results based upon measured data show that under present electricity/gas price ratio, more than 40% of operation cost can be saved by the hybrid system.

  8. Urban Traffic Control Using Adjusted Reinforcement Learning in a Multi-agent System

    Directory of Open Access Journals (Sweden)

    Mahshid Helali Moghadam

    2013-09-01

    Full Text Available Dynamism, continuous changes of states and the necessity to respond quickly are the specific characteristics of the environment in a traffic control system. Proposing an appropriate and flexible strategy to meet the existing requirements is always an important issue in traffic control. This study presents an adaptive approach to control urban traffic using multi-agent systems and a reinforcement learning augmented by an adjusting pre-learning stage. In this approach, the agent primarily uses some statistical traffic data and then uses traffic engineering theories for computing appropriate values of the traffic parameters. Having these primary values, the agents start the reinforcement learning based on the basic calculated information. The proposed approach, at first finds the approximate optimal zone for traffic parameters based on traffic engineering theories. Then using an appropriate reinforcement learning, it tries to exploit the best point according to different conditions. This approach was implemented on a network in traffic simulator software. The network was composed of six four phased intersections and 17 two lane streets. In the simulation, pedestrians were not considered in the system. The load of the network is defined in terms of Origin-Destination matrices whose entries represent the number of trips from an origin to a destination as a function of time. The simulation ran for five hours and an average traffic volume was used. According to the simulation results, the proposed approach behaved adaptively in different conditions and had better performance than the theory-based fixed-time control.

  9. Evaluation of a Compact Hybrid Brain-Computer Interface System

    Directory of Open Access Journals (Sweden)

    Jaeyoung Shin

    2017-01-01

    Full Text Available We realized a compact hybrid brain-computer interface (BCI system by integrating a portable near-infrared spectroscopy (NIRS device with an economical electroencephalography (EEG system. The NIRS array was located on the subjects’ forehead, covering the prefrontal area. The EEG electrodes were distributed over the frontal, motor/temporal, and parietal areas. The experimental paradigm involved a Stroop word-picture matching test in combination with mental arithmetic (MA and baseline (BL tasks, in which the subjects were asked to perform either MA or BL in response to congruent or incongruent conditions, respectively. We compared the classification accuracies of each of the modalities (NIRS or EEG with that of the hybrid system. We showed that the hybrid system outperforms the unimodal EEG and NIRS systems by 6.2% and 2.5%, respectively. Since the proposed hybrid system is based on portable platforms, it is not confined to a laboratory environment and has the potential to be used in real-life situations, such as in neurorehabilitation.

  10. The possibility of developing hybrid PV/T solar system

    Science.gov (United States)

    Dobrnjac, M.; Zivkovic, P.; Babic, V.

    2017-05-01

    An alternative and cost-effective solution to developing integrated PV system is to use hybrid photovoltaic/thermal (PV/T) solar system. The temperature of PV modules increases due to the absorbed solar radiation that is not converted into electricity, causing a decrease in their efficiency. In hybrid PV/T solar systems the reduction of PV module temperature can be combined with a useful fluid heating. In this paper we present the possibility of developing a new hybrid PV/T solar system. Hybrid PV/T system can provide electrical and thermal energy, thus achieving a higher energy conversion rate of the absorbed solar radiation. We developed PV/T prototype consisted of commercial PV module and thermal panel with our original solution of aluminium absorber with special geometric shapes. The main advantages of our combined PV/T system are: removing of heat from the PV panel; extending the lifetime of photovoltaic cells; excess of the removing heat from PV part is used to heat the fluid in the thermal part of the panel; the possibility of using on the roof and facade constructions because less weight.

  11. A special hierarchical fuzzy neural-networks based reinforcement learning for multi-variables system

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wen-zhi; LU Tian-sheng

    2005-01-01

    Proposes a reinforcement learning scheme based on a special Hierarchical Fuzzy Neural-Networks (HFNN) for solving complicated learning tasks in a continuous multi-variables environment. The output of the previous layer in the HFNN is no longer used as if-part of the next layer, but used only in then-part. Thus it can deal with the difficulty when the output of the previous layer is meaningless or its meaning is uncertain. The proposed HFNN has a minimal number of fuzzy rules and can successfully solve the problem of rules combination explosion and decrease the quantity of computation and memory requirement. In the learning process, two HFNN with the same structure perform fuzzy action composition and evaluation function approximation simultaneously where the parameters of neural-networks are tuned and updated on line by using gradient descent algorithm. The reinforcement learning method is proved to be correct and feasible by simulation of a double inverted pendulum system.

  12. Optimization strategy for element sizing in hybrid power systems

    Science.gov (United States)

    del Real, Alejandro J.; Arce, Alicia; Bordons, Carlos

    This paper presents a procedure to evaluate the optimal element sizing of hybrid power systems. In order to generalize the problem, this work exploits the "energy hub" formulation previously presented in the literature, defining an energy hub as an interface among energy producers, consumers and the transportation infrastructure. The resulting optimization minimizes an objective function which is based on costs and efficiencies of the system elements, while taking into account the hub model, energy and power constraints and estimated operational conditions, such as energy prices, input power flow availability and output energy demand. The resulting optimal architecture also constitutes a framework for further real-time control designs. Moreover, an example of a hybrid storage system is considered. In particular, the architecture of a hybrid plant incorporating a wind generator, batteries and intermediate hydrogen storage is optimized, based on real wind data and averaged residential demands, also taking into account possible estimation errors. The hydrogen system integrates an electrolyzer, a fuel cell stack and hydrogen tanks. The resulting optimal cost of such hybrid power plant is compared with the equivalent hydrogen-only and battery-only systems, showing improvements in investment costs of almost 30% in the worst case.

  13. Optimization strategy for element sizing in hybrid power systems

    Energy Technology Data Exchange (ETDEWEB)

    del Real, Alejandro J.; Arce, Alicia; Bordons, Carlos [Departamento de Ingenieria de Sistemas y Automatica, Universidad de Sevilla, 41092 Sevilla (Spain)

    2009-08-01

    This paper presents a procedure to evaluate the optimal element sizing of hybrid power systems. In order to generalize the problem, this work exploits the ''energy hub'' formulation previously presented in the literature, defining an energy hub as an interface among energy producers, consumers and the transportation infrastructure. The resulting optimization minimizes an objective function which is based on costs and efficiencies of the system elements, while taking into account the hub model, energy and power constraints and estimated operational conditions, such as energy prices, input power flow availability and output energy demand. The resulting optimal architecture also constitutes a framework for further real-time control designs. Moreover, an example of a hybrid storage system is considered. In particular, the architecture of a hybrid plant incorporating a wind generator, batteries and intermediate hydrogen storage is optimized, based on real wind data and averaged residential demands, also taking into account possible estimation errors. The hydrogen system integrates an electrolyzer, a fuel cell stack and hydrogen tanks. The resulting optimal cost of such hybrid power plant is compared with the equivalent hydrogen-only and battery-only systems, showing improvements in investment costs of almost 30% in the worst case. (author)

  14. Performance Analysis of a Hybrid Power Cutting System for Roadheader

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2017-01-01

    Full Text Available An electrohydraulic hybrid power cutting transmission system for roadheader under specific working condition was proposed in this paper. The overall model for the new system composed of an electric motor model, a hydraulic pump-motor model, a torsional planetary set model, and a hybrid power train model was established. The working mode characteristics were simulated under the conditions of taking the effect of cutting picks into account. The advantages of new hybrid power cutting system about the dynamic response under shock load were investigated compared with the traditional cutting system. The results illustrated that the hybrid power system had an obvious cushioning in terms of the dynamic load of cutting electric motor and planetary gear set. Besides, the hydraulic motor could provide an auxiliary power to improve the performance of the electric motor. With further analysis, a dynamic load was found to have a high relation to the stiffness and damping of coupling in the transmission train. The results could be a useful guide for the design of cutting transmission of roadheader.

  15. Tensile Mechanical Properties and Strengthening Mechanism of Hybrid Carbon Nanotube and Silicon Carbide Nanoparticle-Reinforced Magnesium Alloy Composites

    National Research Council Canada - National Science Library

    Zhou, Xia; Su, Depeng; Wu, Chengwei; Liu, Liming

    2012-01-01

    .... The results showed that grains of the matrix in the AZ91/(CNT + SiC) composites were obviously refined after adding hybrid CNTs and SiC nanoparticles to the AZ91 alloy, and the room-temperature mechanical properties of AZ91/(CNT + SiC...

  16. Hybrid intelligent monironing systems for thermal power plant trips

    Science.gov (United States)

    Barsoum, Nader; Ismail, Firas Basim

    2012-11-01

    Steam boiler is one of the main equipment in thermal power plants. If the steam boiler trips it may lead to entire shutdown of the plant, which is economically burdensome. Early boiler trips monitoring is crucial to maintain normal and safe operational conditions. In the present work two artificial intelligent monitoring systems specialized in boiler trips have been proposed and coded within the MATLAB environment. The training and validation of the two systems has been performed using real operational data captured from the plant control system of selected power plant. An integrated plant data preparation framework for seven boiler trips with related operational variables has been proposed for IMSs data analysis. The first IMS represents the use of pure Artificial Neural Network system for boiler trip detection. All seven boiler trips under consideration have been detected by IMSs before or at the same time of the plant control system. The second IMS represents the use of Genetic Algorithms and Artificial Neural Networks as a hybrid intelligent system. A slightly lower root mean square error was observed in the second system which reveals that the hybrid intelligent system performed better than the pure neural network system. Also, the optimal selection of the most influencing variables performed successfully by the hybrid intelligent system.

  17. Study of a class of hybrid-time systems

    Energy Technology Data Exchange (ETDEWEB)

    Cervantes, I. [Seccion de Estudios de Posgrado e Investigacion, Escuela Superior de Ingenieria Mecanica y Electrica-Culhuacan-IPN, Av. San Ana 1000 Col. San Fco. Culhuacan, Mexico D.F. 04430 (Mexico) and Insituto Potosino de Investigacion Cientifica y Tecnologica (IPICyT), Departamento de Matematicas Aplicadas y Sistemas Computacionales, Camino a la Presa San Jose 2055, Col. Lomas 4a, seccion C.P. 78216, San Luis Potosi, San Luis Potosi (Mexico)]. E-mail: ilse@calmecac.esimecu.ipn.mx; Femat, R. [Insituto Potosino de Investigacion Cientifica y Tecnologica (IPICyT), Departamento de Matematicas Aplicadas y Sistemas Computacionales, Camino a la Presa San Jose 2055, Col. Lomas 4a, seccion C.P. 78216, San Luis Potosi, San Luis Potosi (Mexico); Leyva-Ramos, J. [Insituto Potosino de Investigacion Cientifica y Tecnologica (IPICyT), Departamento de Matematicas Aplicadas y Sistemas Computacionales, Camino a la Presa San Jose 2055, Col. Lomas 4a, seccion C.P. 78216, San Luis Potosi, San Luis Potosi (Mexico)

    2007-05-15

    The aim of this paper is to study the dynamic behavior of a class of hybrid-time systems. In particular, we concern about switched systems constituted by two linear second order systems with a time varying (sinusoidal type) translation term. By means of numerical simulations, system behavior and its relation to system parameters are studied. It is shown that system eigenvalues play a crucial role in the time evolution of the system leading either to regular behavior, oscillatory patterns or intermittent erratic-periodic behavior. Furthermore, it is shown that under certain conditions, presumable fractal structures can be obtained.

  18. Chaotic attractor transforming control of hybrid Lorenz-Chen system

    Institute of Scientific and Technical Information of China (English)

    Qi Dong-Lian; Wang Qiao; Gu Hong

    2008-01-01

    Based on passive theory, this paper studies a hybrid chaotic dynamical system from the mathematics perspective to implement the control of system stabilization.According to the Jacobian matrix of the nonlinear system, the stabilization control region is gotten.The controller is designed to stabilize fast the minimum phase Lorenz-Chen chaotic system after equivalently transforming from chaotic system to passive system. The simulation results show that the system not only can be controlled at the different equilibria, but also can be transformed between the different chaotic attractors.

  19. Active diagnosis of hybrid systems - A model predictive approach

    OpenAIRE

    2009-01-01

    A method for active diagnosis of hybrid systems is proposed. The main idea is to predict the future output of both normal and faulty model of the system; then at each time step an optimization problem is solved with the objective of maximizing the difference between the predicted normal and faulty outputs constrained by tolerable performance requirements. As in standard model predictive control, the first element of the optimal input is applied to the system and the whole procedure is repeate...

  20. ENERGY MANAGEMENT OF WIND/PV AND BATTERY HYBRID SYSTEM

    OpenAIRE

    M. F. Almi; M. Arrouf; H.Belmili; S. Boulouma; Bendib, B

    2014-01-01

    This paper deals with power control of a wind and solar hybrid generation system for interconnection operation with electric distribution system. Power control strategy is to extract the maximum energy available from varying condition of wind speed and solar irradiance while maintaining power quality at a satisfactory level. In order to capture the maximum power, variable speed control is employed for wind turbine and maximum power point tracking is applied for photovoltaic system. The grid i...

  1. A Hybrid Architecture for Web-based Expert Systems

    OpenAIRE

    Neil Dunstan

    2012-01-01

    A recent technique is to represent the knowledge base of an expert system in XML format. XML parsers are then used to convert XML data into expert system language code. The code is executed or interpreted when providing responses to user queries. Web-based expert system (WBES) architectures may be characterized according to where the application knowledge base resides. Applications of both client and server-sided WBES architectures appear in the literature. A hybrid architecture is proposed w...

  2. THERMOELECTRIC AND MICROBATTERY HYBRID SYSTEM WITH ITS POWER MANAGEMENT

    OpenAIRE

    2006-01-01

    Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/5920); International audience; Integration of a power source with a MEMS to obtain an autonomous or remote system is a very challenging task. Such a device is currently being developed. It consists in hybriding an energy storage system (thin film solid state battery) with a scavenging energy system (thermogenerator) in a very small volume. It requires also power management to both control charge of the batt...

  3. Switches and Jumps in Hybrid Action Systems

    DEFF Research Database (Denmark)

    Rönnkö, Mauno; Ravn, Anders P.

    1998-01-01

    An action system framework is a predicate transformer based method for modelling and analysing distributed and reactive systems. The actions are statements in Dijkstra's guarded command language, and their semantics is given by predicate transformers. We extend conventional action systems with a ...

  4. Hybrid two fuel system nozzle with a bypass connecting the two fuel systems

    Science.gov (United States)

    Varatharajan, Balachandar [Cincinnati, OH; Ziminsky, Willy Steve [Simpsonville, SC; Yilmaz, Ertan [Albany, NY; Lacy, Benjamin [Greer, SC; Zuo, Baifang [Simpsonville, SC; York, William David [Greer, SC

    2012-05-29

    A hybrid fuel combustion nozzle for use with natural gas, syngas, or other types of fuels. The hybrid fuel combustion nozzle may include a natural gas system with a number of swozzle vanes and a syngas system with a number of co-annular fuel tubes.

  5. CPV hybrid system in ISFOC building, first results

    Science.gov (United States)

    Trujillo, Pablo; Alamillo, César; Gil, Eduardo; de la Rubia, Óscar; Martínez, María; Rubio, Francisca; Cadavid, Andros; Navarro, José; Hillenbrand, Sascha; Ballesteros-Sánchez, Isabel; Castillo-Cagigal, Manuel; Masa-Bote, Daniel; Matallanas, Eduardo; Caamaño-Martín, Estefanía; Gutiérrez, Álvaro

    2012-10-01

    PV Off-Grid systems have demonstrated to be a good solution for the electrification of remote areas [1]. A hybrid system is one kind of these systems. The principal characteristic is that it uses PV as the main generator and has a backup power supply, like a diesel generator, for instance, that is used when the CPV generation is not enough to meet demand. To study the use of CPV in these systems, ISFOC has installed a demonstration hybrid system at its headquarters. This hybrid system uses CPV technology as main generator and the utility grid as the backup generator. A group of batteries have been mounted as well to store the remaining energy from the CPV generator when nedeed. The energy flows are managed by a SMA system based on Sunny Island inverters and a Multicluster-Box (figure 1). The Load is the air-conditioning system of the building, as it has a consumption profile higher than the CPV generator and can be controlled by software [2]. The first results of this system, as well as the first chances of improvement, as the need of a bigger CPV generator and a better management of the energy stored in the batteries, are presented in this paper.

  6. Towards a General Theory of Stochastic Hybrid Systems

    NARCIS (Netherlands)

    Bujorianu, L.M.; Lygeros, J.; Bujorianu, M.C.

    2008-01-01

    In this paper we set up a mathematical structure, called Markov string, to obtaining a very general class of models for stochastic hybrid systems. Markov Strings are, in fact, a class of Markov processes, obtained by a mixing mechanism of stochastic processes, introduced by Meyer. We prove that Mark

  7. Toward a General Theory of Stochastic Hybrid Systems

    NARCIS (Netherlands)

    Bujorianu, L.M.; Lygeros, J.; Blom, H.A.P.; Lygeros, J.

    2006-01-01

    In this chapter we set up a mathematical structure, called Markov string, to obtaining a very general class of models for stochastic hybrid systems. Markov Strings are, in fact, a class of Markov processes, obtained by a mixing mechanism of stochastic processes, introduced by Meyer. We prove that Ma

  8. Efficient Proof Engines for Bounded Model Checking of Hybrid Systems

    DEFF Research Database (Denmark)

    Fränzle, Martin; Herde, Christian

    2005-01-01

    In this paper we present HySat, a new bounded model checker for linear hybrid systems, incorporating a tight integration of a DPLL-based pseudo-Boolean SAT solver and a linear programming routine as core engine. In contrast to related tools like MathSAT, ICS, or CVC, our tool exploits all...

  9. Spontaneous emission control in a tunable hybrid photonic system

    NARCIS (Netherlands)

    Frimmer, M.; Koenderink, A.F.

    2013-01-01

    We experimentally demonstrate control of the rate of spontaneous emission in a tunable hybrid photonic system that consists of two canonical building blocks for spontaneous emission control, an optical antenna and a mirror, each providing a modification of the local density of optical states (LDOS).

  10. Nuclear-Renewable Hybrid Energy System Market Analysis Plans

    Energy Technology Data Exchange (ETDEWEB)

    Ruth, Mark

    2016-06-09

    This presentation describes nuclear-renewable hybrid energy systems (N-R HESs), states their potential benefits, provides figures for the four tightly coupled N-R HESs that NREL is currently analyzing, and outlines the analysis process that is underway.

  11. Extending a Hybrid Tag-Based Recommender System with Personalization

    DEFF Research Database (Denmark)

    Durao, Frederico; Dolog, Peter

    2010-01-01

    extension for a hybrid tag-based recommender system, which suggests similar Web pages based on the similarity of their tags. The semantic extension aims at discovering tag relations which are not considered in basic syntax similarity. With the goal of generating more semantically grounded recommendations...

  12. Model-based health monitoring of hybrid systems

    CERN Document Server

    Wang, Danwei; Low, Chang Boon; Arogeti, Shai

    2013-01-01

    Offers in-depth comprehensive study on health monitoring for hybrid systems Includes new concepts, such as GARR, mode tracking and multiple failure prognosis Contains many examples, making the developed techniques easily understandable and accessible Introduces state-of-the-art algorithms and methodologies from experienced researchers

  13. Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Minh

    2005-12-01

    This report summarizes the work performed by Hybrid Power Generation Systems, LLC (HPGS) under Cooperative Agreement DE-FC2601NT40779 for the US Department of Energy, National Energy Technology Laboratory (DoE/NETL) entitled ''Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation''. The main objective of this project is to develop and demonstrate the feasibility of a highly efficient hybrid system integrating a planar Solid Oxide Fuel Cell (SOFC) and a gas turbine. A conceptual hybrid system design was selected for analysis and evaluation. The selected system is estimated to have over 65% system efficiency, a first cost of approximately $650/kW, and a cost of electricity of 8.4 cents/kW-hr. A control strategy and conceptual control design have been developed for the system. A number of SOFC module tests have been completed to evaluate the pressure impact to performance stability. The results show that the operating pressure accelerates the performance degradation. Several experiments were conducted to explore the effects of pressure on carbon formation. Experimental observations on a functioning cell have verified that carbon deposition does not occur in the cell at steam-to-carbon ratios lower than the steady-state design point for hybrid systems. Heat exchanger design, fabrication and performance testing as well as oxidation testing to support heat exchanger life analysis were also conducted. Performance tests of the prototype heat exchanger yielded heat transfer and pressure drop characteristics consistent with the heat exchanger specification. Multicell stacks have been tested and performance maps were obtained under hybrid operating conditions. Successful and repeatable fabrication of large (>12-inch diameter) planar SOFC cells was demonstrated using the tape calendering process. A number of large area cells and stacks were successfully performance tested at ambient and pressurized conditions. A 25 MW plant configuration was

  14. The under-critical reactors physics for the hybrid systems; La physique des reacteurs sous-critiques des systemes hybrides

    Energy Technology Data Exchange (ETDEWEB)

    Schapira, J.P. [Institut de Physique Nucleaire, IN2P3/CNRS 91 - Orsay (France); Vergnes, J. [Electricite de France, EDF, Direction des Etudes et Recherches, 75 - Paris (France); Zaetta, A. [CEA/Saclay, Direction des Reacteurs Nucleaires, DRN, 91 - Gif-sur-Yvette (France)] [and others

    1998-03-12

    This day, organized by the SFEN, took place at Paris the 12 march 1998. Nine papers were presented. They take stock on the hybrid systems and more specifically the under-critical reactors. One of the major current preoccupation of nuclear industry is the problems of the increase of radioactive wastes produced in the plants and the destruction of the present stocks. To solve these problems a solution is the utilisation of hybrid systems: the coupling of a particle acceleration to an under-critical reactor. Historical aspects, advantages and performances of such hybrid reactors are presented in general papers. More technical papers are devoted to the spallation, the MUSE and the TARC experiments. (A.L.B.)

  15. Hybrid control of the distributed refrigeration system

    DEFF Research Database (Denmark)

    Chen, L.; Wisniewski, R.

    2010-01-01

    The supermarket refrigeration system typically has a distributed control structure, which neglects interactions between its subsystems. These interactions from time to time lead to a synchronization operation of the display-cases which causes an inferior control performance and increased energy...... or a chaotic behavior, the system is considered away from the synchronization. Therefore, the paper proposes a concept that the system may be de-synchronized by making it chaotic. A de-synchronization scheme is developed. It includes a synchronization-early-monitoring detector by calculating the maximum...... consumption. The paper focuses on synchronization dynamics of the refrigeration system modeled as a piecewise-affine switched system. System behaviors are analyzed using chaos theory. The synchronization phenomenon is interpreted as a stable low-period orbit; if the system has a high-order periodic orbit...

  16. Hybrid Systems for Knowledge Representation in Artificial Intelligence

    Directory of Open Access Journals (Sweden)

    Rajeswari P.V N

    2012-11-01

    Full Text Available There are few knowledge representation (KR techniques available for efficiently representing knowledge. However, with the increase in complexity, better methods are needed. Some researchers came up with hybrid mechanisms by combining two or more methods. In an effort to construct an intelligent computer system, a primary consideration is to represent large amounts of knowledge in a way that allows effective use and efficiently organizing information to facilitate making the recommended inferences. There are merits and demerits of combinations, and standardized method of KR is needed. In this paper, various hybrid schemes of KR were explored at length and details presented.

  17. A Novel Single Phase Hybrid Switched Reluctance Motor Drive System

    DEFF Research Database (Denmark)

    Liang, Jianing; Xu, Guoqing; Jian, Linni;

    2011-01-01

    phase boost converter is applied to improve the performance of this motor. It is easy to generate a double dclink voltage and dc-link voltage and switch both of them. The voltage of boost capacitor is self balance, so the protective circuit is not need to consider. The fast excitation mode helps hybrid...... SRM reduce the negative torque before zero-crossing point of torque curve, and build desired phase current to generate more power. Some experimental results are done to verify the performance of proposed hybrid SRM drive system....

  18. Advanced hybrid and electric vehicles system optimization and vehicle integration

    CERN Document Server

    2016-01-01

    This contributed volume contains the results of the research program “Agreement for Hybrid and Electric Vehicles”, funded by the International Energy Agency. The topical focus lies on technology options for the system optimization of hybrid and electric vehicle components and drive train configurations which enhance the energy efficiency of the vehicle. The approach to the topic is genuinely interdisciplinary, covering insights from fields. The target audience primarily comprises researchers and industry experts in the field of automotive engineering, but the book may also be beneficial for graduate students.

  19. Quantum dot-dye hybrid systems for energy transfer applications

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Ting

    2010-07-01

    In this thesis, we focus on the preparation of energy transfer-based quantum dot (QD)-dye hybrid systems. Two kinds of QD-dye hybrid systems have been successfully synthesized: QD-silica-dye and QD-dye hybrid systems. In the QD-silica-dye hybrid system, multishell CdSe/CdS/ZnS QDs were adsorbed onto monodisperse Stoeber silica particles with an outer silica shell of thickness 2-24 nm containing organic dye molecules (Texas Red). The thickness of this dye layer has a strong effect on the total sensitized acceptor emission, which is explained by the increase in the number of dye molecules homogeneously distributed within the silica shell, in combination with an enhanced surface adsorption of QDs with increasing dye amount. Our conclusions were underlined by comparison of the experimental results with Monte-Carlo simulations, and by control experiments confirming attractive interactions between QDs and Texas Red freely dissolved in solution. New QD-dye hybrid system consisting of multishell QDs and organic perylene dyes have been synthesized. We developed a versatile approach to assemble extraordinarily stable QD-dye hybrids, which uses dicarboxylate anchors to bind rylene dyes to QD. This system yields a good basis to study the energy transfer between QD and dye because of its simple and compact design: there is no third kind of molecule linking QD and dye; no spacer; and the affinity of the functional group to the QD surface is strong. The FRET signal was measured for these complexes as a function of both dye to QD ratio and center-to-center distance between QD and dye by controlling number of covered ZnS layers. Data showed that fluorescence resonance energy transfer (FRET) was the dominant mechanism of the energy transfer in our QD-dye hybrid system. FRET efficiency can be controlled by not only adjusting the number of dyes on the QD surface or the QD to dye distance, but also properly choosing different dye and QD components. Due to the strong stability, our QD

  20. Strong reinforcing selection in a Texas wildflower.

    Science.gov (United States)

    Hopkins, Robin; Guerrero, Rafael F; Rausher, Mark D; Kirkpatrick, Mark

    2014-09-08

    Reinforcement, the process of increased reproductive isolation due to selection against hybrids, is an important mechanism by which natural selection contributes to speciation [1]. Empirical studies suggest that reinforcement has generated reproductive isolation in many taxa (reviewed in [2-4]), and theoretical work shows it can act under broad selective conditions [5-11]. However, the strength of selection driving reinforcement has never been measured in nature. Here, we quantify the strength of reinforcing selection in the Texas wildflower Phlox drummondii using a strategy that weds a population genetic model with field data. Reinforcement in this system is caused by variation in two loci that affect flower color [12]. We quantify sharp clines in flower color where this species comes into contact with its congener, Phlox cuspidata. We develop a spatially explicit population genetic model for these clines based on the known genetics of flower color. We fit our model to the data using likelihood, and we searched parameter space using Markov chain Monte Carlo methods. We find that selection on flower color genes generated by reinforcement is exceptionally strong. Our findings demonstrate that natural selection can play a decisive role in the evolution of reproductive isolation through the process of reinforcement.

  1. Improving an Hybrid Literary Book Recommendation System through Author Ranking

    CERN Document Server

    Vaz, Paula Cristina; Martins, Bruno; Calado, Pavel

    2012-01-01

    Literary reading is an important activity for individuals and choosing to read a book can be a long time commitment, making book choice an important task for book lovers and public library users. In this paper we present an hybrid recommendation system to help readers decide which book to read next. We study book and author recommendation in an hybrid recommendation setting and test our approach in the LitRec data set. Our hybrid book recommendation approach purposed combines two item-based collaborative filtering algorithms to predict books and authors that the user will like. Author predictions are expanded in to a book list that is subsequently aggregated with the former list generated through the initial collaborative recommender. Finally, the resulting book list is used to yield the top-n book recommendations. By means of various experiments, we demonstrate that author recommendation can improve overall book recommendation.

  2. Breaking Dense Structures: Proving Stability of Densely Structured Hybrid Systems

    Directory of Open Access Journals (Sweden)

    Eike Möhlmann

    2015-06-01

    Full Text Available Abstraction and refinement is widely used in software development. Such techniques are valuable since they allow to handle even more complex systems. One key point is the ability to decompose a large system into subsystems, analyze those subsystems and deduce properties of the larger system. As cyber-physical systems tend to become more and more complex, such techniques become more appealing. In 2009, Oehlerking and Theel presented a (de-composition technique for hybrid systems. This technique is graph-based and constructs a Lyapunov function for hybrid systems having a complex discrete state space. The technique consists of (1 decomposing the underlying graph of the hybrid system into subgraphs, (2 computing multiple local Lyapunov functions for the subgraphs, and finally (3 composing the local Lyapunov functions into a piecewise Lyapunov function. A Lyapunov function can serve multiple purposes, e.g., it certifies stability or termination of a system or allows to construct invariant sets, which in turn may be used to certify safety and security. In this paper, we propose an improvement to the decomposing technique, which relaxes the graph structure before applying the decomposition technique. Our relaxation significantly reduces the connectivity of the graph by exploiting super-dense switching. The relaxation makes the decomposition technique more efficient on one hand and on the other allows to decompose a wider range of graph structures.

  3. Full Mouth Oral Rehabilitation by Maxillary Implant Supported Hybrid Denture Employing a Fiber Reinforced Material Instead of Conventional PMMA

    Science.gov (United States)

    Qamheya, Ala Hassan A.; Yeniyol, Sinem; Arısan, Volkan

    2015-01-01

    Many people have life-long problems with their dentures, such as difficulties with speaking and eating, loose denture, and sore mouth syndrome. The evolution of dental implant supported prosthesis gives these patients normal healthy life for their functional and esthetic advantages. This case report presents the fabrication of maxillary implant supported hybrid prosthesis by using Nanofilled Composite (NFC) material in teeth construction to rehabilitate a complete denture wearer patient. PMID:26557392

  4. Full Mouth Oral Rehabilitation by Maxillary Implant Supported Hybrid Denture Employing a Fiber Reinforced Material Instead of Conventional PMMA

    Directory of Open Access Journals (Sweden)

    Ala Hassan A. Qamheya

    2015-01-01

    Full Text Available Many people have life-long problems with their dentures, such as difficulties with speaking and eating, loose denture, and sore mouth syndrome. The evolution of dental implant supported prosthesis gives these patients normal healthy life for their functional and esthetic advantages. This case report presents the fabrication of maxillary implant supported hybrid prosthesis by using Nanofilled Composite (NFC material in teeth construction to rehabilitate a complete denture wearer patient.

  5. Complex Dynamical Behavior in Hybrid Systems

    Science.gov (United States)

    2012-09-29

    2010. J15. T. Hu, T. Thibodeau , A.R. Teel, ``A Unified Lyapunov Approach to Analysis of Oscillations and Stability for Systems With Piecewise...Hu, T. Thibodeau , A.R. Teel, ``Analysis of oscillation and stability for systems with piecewise linear components via saturation functions

  6. Overview of a Hybrid Underwater Camera System

    Science.gov (United States)

    2014-07-01

    integrated HUC system. As part of the HUC system, the Navigator display is also transmitted to a monocular display installed on a diver’s helmet. An...feet in length, 6.5 feet in width with a maximum depth of 8 feet. Pumps are used to generate a current in the flume. The water holds particulate matter

  7. The Experimental Studies on Behavior of Ultrahigh-Performance Concrete Confined by Hybrid Fiber-Reinforced Polymer Tubes

    Directory of Open Access Journals (Sweden)

    Zong-cai Deng

    2015-01-01

    Full Text Available This paper conducts axial compression test of ultrahigh performance concrete- (UHPC- filled hybrid FRP (HFRP tubes, using the alternating hybrid technology to improve the deformation capacity of FRP tube and measure the axial compressive responses of ultimate strength, strains, and stress-strain curve of confined specimens. The test results show that the local rupture of HFRP tubes did not lead to explosive failure of UHPC cylinder, and its ductility is better than that of UHPC confined by only one type of FRP tube; HFRP tube can effectively improve the compressive strength and ultimate strain of UHPC specimens; the stress-strain curves divide into three distinct regions: linear phase, transition phase, and linear strengthening phase. None of the models provided a reasonable prediction for strength and strain of HFRP-confined UHPC specimen; therefore, a new ultimate strength and strain perdition model considering the confinement effectiveness of different hybrid FRP series was proposed. The new proposed model presented the best fitting results. The stress-strain responses predicted by the existing models are all below the experimental curves; therefore, a new three-stage constitutive model was proposed, which relatively fits the test curves better than the existing models.

  8. Hybrid Photovoltaic-Hydrogen Power Conditioning System

    Science.gov (United States)

    Garrigos, A.; Blanes, J. M.; Carrasco, J. A.; Maset, E.; Ejea, J. B.; Ferreres, A.; Sanchis, E.

    2011-10-01

    This paper explores a power conditioning unit for photovoltaic/hydrogen based energy systems. Similar power conversion techniques, compared to traditional space power systems, are applied. An S4R regulator is devised with an unregulated battery bus as primary output and a secondary path to feed and electrolyser. A modular fuel cell converter completes the system and it operates when photovoltaic energy is not available or load demand exceeds solar power, i. e. like a traditional BDR. An ancillary battery keeps the unregulated bus voltage distributed in the system and it also aids the fuel cell during transients or start-up due to its limited speed. A 1kW breadboard has been designed and implemented to corroborate the proposed system.

  9. A Hybrid Approach to the Optimization of Multiechelon Systems

    Directory of Open Access Journals (Sweden)

    Paweł Sitek

    2015-01-01

    Full Text Available In freight transportation there are two main distribution strategies: direct shipping and multiechelon distribution. In the direct shipping, vehicles, starting from a depot, bring their freight directly to the destination, while in the multiechelon systems, freight is delivered from the depot to the customers through an intermediate points. Multiechelon systems are particularly useful for logistic issues in a competitive environment. The paper presents a concept and application of a hybrid approach to modeling and optimization of the Multi-Echelon Capacitated Vehicle Routing Problem. Two ways of mathematical programming (MP and constraint logic programming (CLP are integrated in one environment. The strengths of MP and CLP in which constraints are treated in a different way and different methods are implemented and combined to use the strengths of both. The proposed approach is particularly important for the discrete decision models with an objective function and many discrete decision variables added up in multiple constraints. An implementation of hybrid approach in the ECLiPSe system using Eplex library is presented. The Two-Echelon Capacitated Vehicle Routing Problem (2E-CVRP and its variants are shown as an illustrative example of the hybrid approach. The presented hybrid approach will be compared with classical mathematical programming on the same benchmark data sets.

  10. Mars Hybrid Propulsion System Trajectory Analysis. Part I; Crew Missions

    Science.gov (United States)

    Chai, Patrick R.; Merrill, Raymond G.; Qu, Min

    2015-01-01

    NASAs Human spaceflight Architecture team is developing a reusable hybrid transportation architecture in which both chemical and electric propulsion systems are used to send crew and cargo to Mars destinations such as Phobos, Deimos, the surface of Mars, and other orbits around Mars. By combining chemical and electrical propulsion into a single space- ship and applying each where it is more effective, the hybrid architecture enables a series of Mars trajectories that are more fuel-efficient than an all chemical architecture without significant increases in flight times. This paper provides the analysis of the interplanetary segments of the three Evolvable Mars Campaign crew missions to Mars using the hybrid transportation architecture. The trajectory analysis provides departure and arrival dates and propellant needs for the three crew missions that are used by the campaign analysis team for campaign build-up and logistics aggregation analysis. Sensitivity analyses were performed to investigate the impact of mass growth, departure window, and propulsion system performance on the hybrid transportation architecture. The results and system analysis from this paper contribute to analyses of the other human spaceflight architecture team tasks and feed into the definition of the Evolvable Mars Campaign.

  11. Event-triggered hybrid control based on multi-Agent systems for Microgrids

    DEFF Research Database (Denmark)

    Dou, Chun-xia; Liu, Bin; Guerrero, Josep M.

    2014-01-01

    of distributed energy resources, thus it is typical hybrid dynamic network. Considering the complex hybrid behaviors, a hierarchical decentralized coordinated control scheme is firstly constructed based on multi-agent sys-tem, then, the hybrid model of the microgrid is built by using differential hybrid Petri...

  12. Sizing PV-wind hybrid energy system for lighting

    Directory of Open Access Journals (Sweden)

    Mustafa Engin

    2012-09-01

    Full Text Available Sizing of wind and photovoltaic generators ensures lower operational costs and therefore, is considered as an important issue. An approach for sizing along with a best management technique for a PV-wind hybrid system with batteries is proposed in this paper, in which the best size for every component of the system could be optimized according to the weather conditions and the load profile. The average hourly values for wind speed and solar radiation for Izmir, Turkey has been used in the design of the systems, along with expected load profile. A hybrid power model is also developed for battery operation according to the power balance between generators and loads used in the software, to anticipate performances for the different systems according to the different weather conditions. The output of the program will display the performance of the system during the year, the total cost of the system, and the best size for the PV-generator, wind generator, and battery capacity. Using proposed procedure, a 1.2 kWp PV-wind hybrid system was designed for Izmir, and simulated and measured results are presented.

  13. A Review of Hybrid Solar PV and Wind Energy System

    Directory of Open Access Journals (Sweden)

    Rashid Al Badwawi

    2015-07-01

    Full Text Available Due to the fact that solar and wind power is intermittent and unpredictable in nature, higher penetration of their types in existing power system could cause and create high technical challenges especially to weak grids or stand-alone systems without proper and enough storage capacity. By integrating the two renewable resources into an optimum combination, the impact of the variable nature of solar and wind resources can be partially resolved and the overall system becomes more reliable and economical to run. This paper provides a review of challenges and opportunities / solutions of hybrid solar PV and wind energy integration systems. Voltage and frequency fluctuation, and harmonics are major power quality issues for both grid-connected and stand-alone systems with bigger impact in case of weak grid. This can be resolved to a large extent by having proper design, advanced fast response control facilities, and good optimization of the hybrid systems. The paper gives a review of the main research work reported in the literature with regard to optimal sizing design, power electronics topologies and control. The paper presents a review of the state of the art of both grid-connected and stand-alone hybrid solar and wind systems.

  14. Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    David Deangelis; Rich Depuy; Debashis Dey; Georgia Karvountzi; Nguyen Minh; Max Peter; Faress Rahman; Pavel Sokolov; Deliang Yang

    2004-09-30

    This report summarizes the work performed by Hybrid Power Generation Systems, LLC (HPGS) during the April to October 2004 reporting period in Task 2.3 (SOFC Scaleup for Hybrid and Fuel Cell Systems) under Cooperative Agreement DE-FC26-01NT40779 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL), entitled ''Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation''. This study analyzes the performance and economics of power generation systems for central power generation application based on Solid Oxide Fuel Cell (SOFC) technology and fueled by natural gas. The main objective of this task is to develop credible scale up strategies for large solid oxide fuel cell-gas turbine systems. System concepts that integrate a SOFC with a gas turbine were developed and analyzed for plant sizes in excess of 20 MW. A 25 MW plant configuration was selected with projected system efficiency of over 65% and a factory cost of under $400/kW. The plant design is modular and can be scaled to both higher and lower plant power ratings. Technology gaps and required engineering development efforts were identified and evaluated.

  15. Sizing and Simulation of PV-Wind Hybrid Power System

    Directory of Open Access Journals (Sweden)

    Mustafa Engin

    2013-01-01

    Full Text Available A sizing procedure is developed for hybrid system with the aid of mathematical models for photovoltaic cell, wind turbine, and battery that are readily present in the literature. This sizing procedure can simulate the annual performance of different kinds of photovoltaic-wind hybrid power system structures for an identified set of renewable resources, which fulfills technical limitations with the lowest energy cost. The output of the program will display the performance of the system during the year, the total cost of the system, and the best size for the PV-generator, wind generator, and battery capacity. Security lightning application is selected, whereas system performance data and environmental operating conditions are measured and stored. This hybrid system, which includes a PV, wind turbine, inverter, and a battery, was installed to supply energy to 24 W lamps, considering that the renewable energy resources of this site where the system was installed were 1700 Wh/m2/day solar radiation and 3.43 m/s yearly average wind speed. Using the measured variables, the inverter and charge regulator efficiencies were calculated as 90% and 98%, respectively, and the overall system’s electrical efficiency is calculated as 72%. Life cycle costs per kWh are found to be $0.89 and LLP = 0.0428.

  16. Wind hybrid electrical supply system: behaviour simulation and sizing optimization

    Science.gov (United States)

    Notton, G.; Cristofari, C.; Poggi, P.; Muselli, M.

    2001-04-01

    Using a global approach, a wind hybrid system operation is simulated and the evolution of several parameters is analysed, such as the wasted energy, the fuel consumption and the role of the wind turbine subsystem in the global production. This analysis shows that all the energies which take part in the system operation are more dependent on the wind turbine size than on the battery storage capacity. A storage of 2 or 3 days is sufficient, because an increase in storage beyond these values does not have a notable impact on the performance of the wind hybrid system. Finally, a cost study is performed to determine the optimal configuration of the system conducive to the lowest cost of electricity production.

  17. H∞ Controller Design for Asynchronous Hybrid Systems with Multiple Delays

    Directory of Open Access Journals (Sweden)

    Xiaoqiang Sun

    2016-01-01

    Full Text Available Solutions for the H∞ synthesis problems of asynchronous hybrid systems with input-output delays are proposed. The continuous-time lifting approach of sampled-data systems is extended to a hybrid system with multiple delays, and some feasible formulas to calculate the operators of the equivalent discrete-time (DT system are given. Different from the existing methods derived from symplectic pair theory or by state augmentation, a Lyapunov-Krasovskii functional to solve the synthesis problem is explicitly constructed. The delay-dependent stability conditions we obtained can be described in terms of nonstrict linear matrix inequalities (LMIs, which are much more convenient to be solved by LMI tools.

  18. Nuclear Hybrid Energy Systems: Molten Salt Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    P. Sabharwall; M. Green; S.J. Yoon; S.M. Bragg-Sitton; C. Stoots

    2014-07-01

    With growing concerns in the production of reliable energy sources, the next generation in reliable power generation, hybrid energy systems, are being developed to stabilize these growing energy needs. The hybrid energy system incorporates multiple inputs and multiple outputs. The vitality and efficiency of these systems resides in the energy storage application. Energy storage is necessary for grid stabilizing and storing the overproduction of energy to meet peak demands of energy at the time of need. With high thermal energy production of the primary nuclear heat generation source, molten salt energy storage is an intriguing option because of its distinct properties. This paper will discuss the different energy storage options with the criteria for efficient energy storage set forth, and will primarily focus on different molten salt energy storage system options through a thermodynamic analysis

  19. Photovoltaic-wind hybrid system for permanent magnet DC motor

    Science.gov (United States)

    Nasir, M. N. M.; Lada, M. Y.; Baharom, M. F.; Jaafar, H. I.; Ramani, A. N.; Sulaima, M. F.

    2015-05-01

    Hybrid system of Photovoltaic (PV) - Wind turbine (WT) generation has more advantages and reliable compared to PV or wind turbine system alone. The aim of this paper is to model and design hybrid system of PV-WT supplying 100W permanent-magnet dc motor. To achieve the objective, both of PV and WT are connected to converter in order to get the same source of DC supply. Then both sources were combined and straightly connected to 100W permanent magnet dc motor. All the works in this paper is only applied in circuit simulator by using Matlab Simulink. The output produced from each converter is expected to be suit to the motor specification. The output produced from each renewable energy system is as expected to be high as it can support the motor if one of them is breakdown

  20. Confirmation of linear system theory prediction: Changes in Herrnstein's k as a function of changes in reinforcer magnitude

    Science.gov (United States)

    McDowell, J. J; Wood, Helena M.

    1984-01-01

    Eight human subjects pressed a lever on a range of variable-interval schedules for 0.25¢ to 35.0¢ per reinforcement. Herrnstein's hyperbola described seven of the eight subjects' response-rate data well. For all subjects, the y-asymptote of the hyperbola increased with increasing reinforcer magnitude and its reciprocal was a linear function of the reciprocal of reinforcer magnitude. These results confirm predictions made by linear system theory; they contradict formal properties of Herrnstein's account and of six other mathematical accounts of single-alternative responding. PMID:16812366

  1. Performance analysis of hybrid district heating system

    DEFF Research Database (Denmark)

    Mikulandric, Robert; Krajačić, Goran; Khavin, Gennadii

    2013-01-01

    as problems related to transportation, storage and environmental impacts of biomass and waste utilisation. Implementation of heat storages in district heating systems could contribute to integration of intermittent energy sources. Hybridisation of heat production facility combines two or more different energy...... that combines different energy sources for heat production will be used. The work has been carried out in scope of 4th Generation District Heating Technologies and Systems project.......District heating system could contribute to more efficient heat generation through cogeneration power plants or waste heat utilization facilities and to increase of renewable energy sources share in total energy consumption. In the most developed EU countries, renewable energy sources have been...

  2. Hybrid Expert Systems In Image Analysis

    Science.gov (United States)

    Dixon, Mark J.; Gregory, Paul J.

    1987-04-01

    Vision systems capable of inspecting industrial components and assemblies have a large potential market if they can be easily programmed and produced quickly. Currently, vision application software written in conventional high-level languages such as C or Pascal are produced by experts in program design, image analysis, and process control. Applications written this way are difficult to maintain and modify. Unless other similar inspection problems can be found, the final program is essentially one-off redundant code. A general-purpose vision system targeted for the Visual Machines Ltd. C-VAS 3000 image processing workstation, is described which will make writing image analysis software accessible to the non-expert both in programming computers and image analysis. A significant reduction in the effort required to produce vision systems, will be gained through a graphically-driven interactive application generator. Finally, an Expert System will be layered on top to guide the naive user through the process of generating an application.

  3. A hybrid stepping motor system with dual CPU

    Institute of Scientific and Technical Information of China (English)

    高晗璎; 赵克; 孙力

    2004-01-01

    An indirect method of measuring the rotor position based on the magnetic reluctance variation is presented in the paper. A single-chip microprocessor 80C196KC is utilized to compensate the phase shift produeed by the process of position signals. At the same time, a DSP (Data Signal Processor) unit is used to realize the speed and current closed-loops of the hybrid stepping motor system. At last, experimental results show the control system has excellent static and dynamic characteristics.

  4. Research on Hybrid Seismic Response Control System for Motion Control of Two Span Bridge

    Science.gov (United States)

    Heo, G.; Kim, C.; Jeon, S.; Seo, S.; Jeon, J.

    2016-09-01

    In this paper, a hybrid seismic response control (HSRC) system was developed to control bridge motion caused by seismic load. It was aimed at optimum vibration control, composed of a rubber bearing of passive type and a MR-damper of semi-active type. The bridge model was built for experiment, a two-span bridge of 8.3 meters in length with the HSRC system put up on it. Then, inflicting El-centro seismic load on it, shaking table tests were carried out to confirm the system's validity. The experiments were conducted under the basic structure state (without an MR-damper applied) first, and then under the state with an MR-damper applied. It was also done under the basic structure state with a reinforced rubber bearing applied, then the passive on/off state of the HSRC system, and finally the semi-active state where the control algorithm was applied to the system. From the experiments, it was observed that collision rather increased when the MR-damper alone was applied, and also that the application of the HSRC system effectively prevented it from occurring. As a result, the HSRC system was proven to be effective in mitigating responses of the two-span bridge under seismic load.

  5. Three Sides Billboard Wind-Solar Hybrid System Design

    Directory of Open Access Journals (Sweden)

    Bai Xuefeng

    2015-01-01

    Full Text Available With the high development of world economy, the demand of energy is increasing all the time, As energy shortage and environment problem are increasing outstanding, Renewable energy has been attracting more and more attention. A kind of three sides billboard supply by wind-Solar hybrid system has been designed in this paper, the overall structure of the system, components, working principle and control strategy has been analyzed from the system perspective. The software and hardware of the system are debugged together and the result is acquired. System function is better and has achieved the expected results.

  6. ARTIFICIAL NEURAL NETWORKS BASED GEARS MATERIAL SELECTION HYBRID INTELLIGENT SYSTEM

    Institute of Scientific and Technical Information of China (English)

    X.C. Li; W.X. Zhu; G. Chen; D.S. Mei; J. Zhang; K.M. Chen

    2003-01-01

    An artificial neural networks(ANNs) based gear material selection hybrid intelligent system is established by analyzing the individual advantages and weakness of expert system (ES) and ANNs and the applications in material select of them. The system mainly consists of tow parts: ES and ANNs. By being trained with much data samples,the back propagation (BP) ANN gets the knowledge of gear materials selection, and is able to inference according to user input. The system realizes the complementing of ANNs and ES. Using this system, engineers without materials selection experience can conveniently deal with gear materials selection.

  7. Influence of the Sr and Mg Alloying Additions on the Bonding Between Matrix and Reinforcing Particles in the AlSi7Mg/SiC-Cg Hybrid Composite

    Directory of Open Access Journals (Sweden)

    Dolata A. J.

    2016-06-01

    Full Text Available The aim of the work was to perform adequate selection of the phase composition of the composite designated for permanent - mould casting air compressor pistons. The hybrid composites based on AlSi7Mg matrix alloy reinforced with mixture of silicon carbide (SiC and glassy carbon (Cg particles were fabricated by the stir casting method. It has been shown that the proper selection of chemical composition of matrix alloy and its modification by used magnesium and strontium additions gives possibility to obtain both the advantageous casting properties of composite suspensions as well as good bonding between particles reinforcements and matrix.

  8. Hybrid HVAC systems with chemical dehumidification for supermarket applications

    Energy Technology Data Exchange (ETDEWEB)

    Capozzoli, Alfonso; Mazzei, Pietro; Minichiello, Francesco; Palma, Daniele [DETEC, University of Naples Federico II, P.le Tecchio, 80, 80125 Naples (Italy)

    2006-06-15

    HVAC systems in supermarkets must assure both thermal comfort for occupants and suitable climatic conditions for refrigerated cases, which operate better with low ambient relative humidity (40-45%). Since open display cases substantially reduce sensible load and moderately reduce latent load, ambient sensible/total heat load ratio is less than usual. Thus, if dehumidification is carried out with a traditional cooling coil, over-sizing of the coil and re-heating of the treated air are necessary, with energy and economic waste. To offset these disadvantages, hybrid HVAC systems with chemical dehumidification may be employed. In this paper a case study is presented in which a traditional HVAC system is compared to hybrid systems with chemical dehumidification. Dynamic simulation codes (DOE and DesiCalc{sup (}TM)) and test reference year data (TRY), opportunely elaborated, have been used. Annual operating costs have been estimated and large savings have been obtained with hybrid systems. Considerable reduction of electric energy demand as well as better control of thermal-hygrometric conditions were noted. A simple payback of about 1 year has been obtained. Finally, a virtual retrofitting operation on 30% of the existing HVAC systems in Italian supermarkets has shown significant operating cost savings. [Author].

  9. Quantum state engineering in hybrid open quantum systems

    Science.gov (United States)

    Joshi, Chaitanya; Larson, Jonas; Spiller, Timothy P.

    2016-04-01

    We investigate a possibility to generate nonclassical states in light-matter coupled noisy quantum systems, namely, the anisotropic Rabi and Dicke models. In these hybrid quantum systems, a competing influence of coherent internal dynamics and environment-induced dissipation drives the system into nonequilibrium steady states (NESSs). Explicitly, for the anisotropic Rabi model, the steady state is given by an incoherent mixture of two states of opposite parities, but as each parity state displays light-matter entanglement, we also find that the full state is entangled. Furthermore, as a natural extension of the anisotropic Rabi model to an infinite spin subsystem, we next explored the NESS of the anisotropic Dicke model. The NESS of this linearized Dicke model is also an inseparable state of light and matter. With an aim to enrich the dynamics beyond the sustainable entanglement found for the NESS of these hybrid quantum systems, we also propose to combine an all-optical feedback strategy for quantum state protection and for establishing quantum control in these systems. Our present work further elucidates the relevance of such hybrid open quantum systems for potential applications in quantum architectures.

  10. Experiences from the Roadrunner petascale hybrid systems

    Energy Technology Data Exchange (ETDEWEB)

    Kerbyson, Darren J [Los Alamos National Laboratory; Pakin, Scott [Los Alamos National Laboratory; Lang, Mike [Los Alamos National Laboratory; Sancho Pitarch, Jose C [Los Alamos National Laboratory; Davis, Kei [Los Alamos National Laboratory; Barker, Kevin J [Los Alamos National Laboratory; Peraza, Josh [Los Alamos National Laboratory

    2010-01-01

    The combination of flexible microprocessors (AMD Opterons) with high-performing accelerators (IBM PowerXCell 8i) resulted in the extremely powerful Roadrunner system. Many challenges in both hardware and software were overcome to achieve its goals. In this talk we detail some of the experiences in achieving performance on the Roadrunner system. In particular we examine several implementations of the kernel application, Sweep3D, using a work-queue approach, a more portable Thread-building-blocks approach, and an MPI on the accelerator approach.

  11. Performance analysis of hybrid district heating system

    DEFF Research Database (Denmark)

    Mikulandric, Robert; Krajačić, Goran; Khavin, Gennadii

    2013-01-01

    as problems related to transportation, storage and environmental impacts of biomass and waste utilisation. Implementation of heat storages in district heating systems could contribute to integration of intermittent energy sources. Hybridisation of heat production facility combines two or more different energy...... more extensively used in district heating systems either separately or as a supplement to traditional fossil fuels in order to achieve national energy policy objectives. However, they are still facing problems such as high intermittences, high energy production costs and low load factors as well...

  12. The Central Reinforcing Properties of Ethanol Are Mediated by Endogenous Opioid Systems: Effects of Mu and Kappa Opioid Antagonists.

    Directory of Open Access Journals (Sweden)

    Norman E. Spear

    2009-09-01

    Full Text Available Endogenous opioid systems are implicated in the reinforcing effects of ethanol and may play a substantial role in modulating the central reinforcing effects of ethanol early in ontogeny. This possibility was explored in the present study through the use of an olfactory conditioning paradigm with centrally administered ethanol serving as an unconditioned stimulus (US. In Experiment 1, newborn rat pups were treated with either a selective mu antagonist CTOP or kappa selective antagonist nor-BNI prior to olfactory conditioning. Experiment 2 tested the effectiveness of an alternative, shorter-duration kappa opioid antagonist GNTI in altering ethanol reinforcement. Experiment 3 investigated whether the effectiveness of pharmacological blockade of opioid receptors was due to the disruption of learning per se using an olfactory aversive conditioning paradigm with intraoral quinine serving as a US. Central administration of either mu or kappa opioid antagonists prior to conditioning disrupted the reinforcing effects of ethanol in newborn rats. The kappa opioid antagonist GNTI was as effective as nor-BNI. These effects of opioid antagonists on ethanol reinforcement are unlikely to be due to a disruption of all types of conditioning, since CTOP did not affect aversive reinforcement to intraoral infusions of quinine. The present results support the hypothesis that in newborn rats, the reinforcing properties of ethanol are mediated by the endogenous activity at mu and kappa opioid receptors.

  13. User Controllability in a Hybrid Recommender System

    Science.gov (United States)

    Parra Santander, Denis Alejandro

    2013-01-01

    Since the introduction of Tapestry in 1990, research on recommender systems has traditionally focused on the development of algorithms whose goal is to increase the accuracy of predicting users' taste based on historical data. In the last decade, this research has diversified, with "human factors" being one area that has received…

  14. Advanced Propulsion Power Distribution System for Next Generation Electric/Hybrid Vehicle. Phase 1; Preliminary System Studies

    Science.gov (United States)

    Bose, Bimal K.; Kim, Min-Huei

    1995-01-01

    The report essentially summarizes the work performed in order to satisfy the above project objective. In the beginning, different energy storage devices, such as battery, flywheel and ultra capacitor are reviewed and compared, establishing the superiority of the battery. Then, the possible power sources, such as IC engine, diesel engine, gas turbine and fuel cell are reviewed and compared, and the superiority of IC engine has been established. Different types of machines for drive motor/engine generator, such as induction machine, PM synchronous machine and switched reluctance machine are compared, and the induction machine is established as the superior candidate. Similar discussion was made for power converters and devices. The Insulated Gate Bipolar Transistor (IGBT) appears to be the most superior device although Mercury Cadmium Telluride (MCT) shows future promise. Different types of candidate distribution systems with the possible combinations of power and energy sources have been discussed and the most viable system consisting of battery, IC engine and induction machine has been identified. Then, HFAC system has been compared with the DC system establishing the superiority of the former. The detailed component sizing calculations of HFAC and DC systems reinforce the superiority of the former. A preliminary control strategy has been developed for the candidate HFAC system. Finally, modeling and simulation study have been made to validate the system performance. The study in the report demonstrates the superiority of HFAC distribution system for next generation electric/hybrid vehicle.

  15. A Review of Hybrid Renewable Energy Systems for Electric Power Generation

    OpenAIRE

    Md. Ibrahim; Abul Khair

    2015-01-01

    Integration and combined utilization of renewable energy sources are becoming increasingly attractive. This paper is a review of hybrid renewable energy systems technologies for power generation, important issues and challenges in their design stage. Generation technology selection and unit sizing, System configurations and Energy management and control are discussed. Applications of hybrid energy systems, advantages of hybrid energy systems, issues and problems related to hybrid ...

  16. Nuclear Hybrid Energy Systems Regional Studies: West Texas & Northeastern Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Humberto E. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Chen, Jun [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kim, Jong Suk [Idaho National Lab. (INL), Idaho Falls, ID (United States); McKellar, Michael George [Idaho National Lab. (INL), Idaho Falls, ID (United States); Deason, Wesley R [Idaho National Lab. (INL), Idaho Falls, ID (United States); Vilim, Richard B. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bragg-Sitton, Shannon M. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Boardman, Richard D. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-04-01

    The primary objective of this study is to conduct a preliminary dynamic analysis of two realistic hybrid energy systems (HES) including a nuclear reactor as the main baseload heat generator (denoted as nuclear HES or nuclear hybrid energy systems [[NHES]) and to assess the local (e.g., HES owners) and system (e.g., the electric grid) benefits attainable by the application of NHES in scenarios with multiple commodity production and high penetration of renewable energy. It is performed for regional cases not generic examples based on available resources, existing infrastructure, and markets within the selected regions. This study also briefly addresses the computational capabilities developed to conduct such analyses, reviews technical gaps, and suggests some research paths forward.

  17. Recent advances on hybrid approaches for designing intelligent systems

    CERN Document Server

    Melin, Patricia; Pedrycz, Witold; Kacprzyk, Janusz

    2014-01-01

    This book describes recent advances on hybrid intelligent systems using soft computing techniques for diverse areas of application, such as intelligent control and robotics, pattern recognition, time series prediction and optimization complex problems. Soft Computing (SC) consists of several intelligent computing paradigms, including fuzzy logic, neural networks, and bio-inspired optimization algorithms, which can be used to produce powerful hybrid intelligent systems. The book is organized in five main parts, which contain a group of papers around a similar subject. The first part consists of papers with the main theme of type-2 fuzzy logic, which basically consists of papers that propose new models and applications for type-2 fuzzy systems. The second part contains papers with the main theme of bio-inspired optimization algorithms, which are basically papers using nature-inspired techniques to achieve optimization of complex optimization problems in diverse areas of application. The third part contains pape...

  18. A Review of Hybrid Brain-Computer Interface Systems

    Directory of Open Access Journals (Sweden)

    Setare Amiri

    2013-01-01

    Full Text Available Increasing number of research activities and different types of studies in brain-computer interface (BCI systems show potential in this young research area. Research teams have studied features of different data acquisition techniques, brain activity patterns, feature extraction techniques, methods of classifications, and many other aspects of a BCI system. However, conventional BCIs have not become totally applicable, due to the lack of high accuracy, reliability, low information transfer rate, and user acceptability. A new approach to create a more reliable BCI that takes advantage of each system is to combine two or more BCI systems with different brain activity patterns or different input signal sources. This type of BCI, called hybrid BCI, may reduce disadvantages of each conventional BCI system. In addition, hybrid BCIs may create more applications and possibly increase the accuracy and the information transfer rate. However, the type of BCIs and their combinations should be considered carefully. In this paper, after introducing several types of BCIs and their combinations, we review and discuss hybrid BCIs, different possibilities to combine them, and their advantages and disadvantages.

  19. A Review of Hybrid Renewable Energy Systems for Electric Power Generation

    Directory of Open Access Journals (Sweden)

    Md. Ibrahim

    2015-08-01

    Full Text Available Integration and combined utilization of renewable energy sources are becoming increasingly attractive. This paper is a review of hybrid renewable energy systems technologies for power generation, important issues and challenges in their design stage. Generation technology selection and unit sizing, System configurations and Energy management and control are discussed. Applications of hybrid energy systems, advantages of hybrid energy systems, issues and problems related to hybrid energy systems and an overview of energy storage technologies for renewable energy systems are presented. This paper also highlights the future trends of Hybrid energy systems, which represent a promising sustainable solution for power generation.

  20. How to take absorptive surfaces into account when designing outdoor sound reinforcement systems

    DEFF Research Database (Denmark)

    Rasmussen, Karsten bo

    1996-01-01

    When sound reinforcement systems are used outdoors, absorptive surfaces are usually present along the propagation path of the sound. This may lead to a very significant colouration of the spectrum received by the audience. The colouration depends on the location and directivity of the loudspeaker......, the nature of the absorptive surface (eg grass) and the location of the audience. It is discussed how this effect may be calculated and numerical examples are shown. The results show a significant colouration and attenuation of the sound due to grass-covered surfaces....