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Sample records for rigidly connected system

  1. Comparison of two systems for rigidly connecting 2.0-mm bone screws to an implantable device : in vitro stability testing

    NARCIS (Netherlands)

    van Loon, JP; de Bont, LGM; Verkerke, GJ

    The stability of a screw-fixed implantable device can be improved by eliminating the freedom of movement between the screws and the device. Two systems have been developed for rigidly connecting 2.0-mm bone screws to an implantable device, and the aim of this study was to test and compare the

  2. Verification of the Seismic Performance of a Rigidly Connected Modular System Depending on the Shape and Size of the Ceiling Bracket

    Directory of Open Access Journals (Sweden)

    Seungjae Lee

    2017-03-01

    Full Text Available Modular systems have been mostly researched in relatively low-rise structures but, lately, their applications to mid- to high-rise structures began to be reviewed, and research interest in new modularization subjects has increased. The application of modular systems to mid- to high-rise structures requires the structural stability of the frame and connections that consist of units, and the evaluation of the stiffness of structures that are combined in units. However, the combination of general units causes loss of the cross-section of columns or beams, resulting in low seismic performance and hindering installation works in the field. In addition, the evaluation of a frame considering such a cross-sectional loss is not easy. Therefore, it is necessary to develop a joint that is stable and easy to install. In the study, a rigidly connected modular system was proposed as a moment-resisting frame for a unit modular system, and their joints were developed and their performances were compared. The proposed system changed the ceiling beam into a bracket type to fasten bolts. It can be merged with other seismic force-resisting systems. To verify the seismic performance of the proposed system, a cyclic loading test was conducted, and the rigidly connected joint performance and integrated behavior at the joint of modular units were investigated. From the experimental results, the maximum resisting force of the proposed connection exceeded the theoretical parameters, indicating that a rigid joint structural performance could be secured.

  3. Connect-disconnect coupling for preadjusted rigid shafts

    Science.gov (United States)

    Bajkowski, F. W.; Holmberg, A.

    1969-01-01

    Coupling device enables a rigid shaft to be connected to or disconnected from a fixed base without disturbing the point of adjustment of the shaft in a socket or causing the shaft to rotate. The coupling consists of an externally threaded, internally slotted boss extending from the fixed base.

  4. Rigid multibody system dynamics with uncertain rigid bodies

    Energy Technology Data Exchange (ETDEWEB)

    Batou, A., E-mail: anas.batou@univ-paris-est.fr; Soize, C., E-mail: christian.soize@univ-paris-est.fr [Universite Paris-Est, Laboratoire Modelisation et Simulation Multi Echelle, MSME UMR 8208 CNRS (France)

    2012-03-15

    This paper is devoted to the construction of a probabilistic model of uncertain rigid bodies for multibody system dynamics. We first construct a stochastic model of an uncertain rigid body by replacing the mass, the center of mass, and the tensor of inertia by random variables. The prior probability distributions of the stochastic model are constructed using the maximum entropy principle under the constraints defined by the available information. The generators of independent realizations corresponding to the prior probability distribution of these random quantities are further developed. Then several uncertain rigid bodies can be linked to each other in order to calculate the random response of a multibody dynamical system. An application is proposed to illustrate the theoretical development.

  5. Connections rigidity effect on probability of fracture in steel moment frames

    Directory of Open Access Journals (Sweden)

    Gholamreza Abdollahzadeh

    2017-08-01

    Full Text Available Connections in steel moment frames are idealized in full pinned and full rigid conditions. Because with this assumption, in spite of real behavior of connection, real story drifts are less anticipated and maybe frame is designed without performance of bracing. There are several methods for modeling actual behavior of semi rigid connections. In this method a connection with certain rigidity is modeled by a rotational spring with corresponding stiffness. This stiffness is achieved by certain formula. In other words, each percent of rigidity corresponds to one rotational spring stiffness. In this research in order to evaluate the real behavior of connection in analysis and designing process and fracture probability one frame including four stories and one bay with three types of connection has been modeled and designed in ETABS. Each model has an individual rigidity which is equal to 10, 75 and 90 percent. With respect to maximum drift and different PGA in roof, probabilities of low, medium, high and complete fracture were calculated. For this purpose, with applying different PGA to modeled frames, amounts of drift in the roof are achieved. Then these values are compared with given values in American code. Finally, investigation showed that when rigidity in frame connections increases, the probability of frame fracture decreases. In other words, fully rigid assumption of connection in analysis process leads to decreasing in real probability of fracture in frames which is a noticeable risk in building designing processes.

  6. Analysis of the Behaviour of Semi Rigid Steel End Plate Connections

    Directory of Open Access Journals (Sweden)

    Bahaz A.

    2018-01-01

    Full Text Available The analysis of steel-framed building structures with full strength beam to column joints is quite standard nowadays. Buildings utilizing such framing systems are widely used in design practice. However, there is a growing recognition of significant benefits in designing joints as partial strength/semi-rigid. The design of joints within this partial strength/semi-rigid approach is becoming more and more popular. This requires the knowledge of the full nonlinear moment-rotation behaviour of the joint, which is also a design parameter. The rotational behaviour of steel semi rigid connections can be studied using the finite element method for the following three reasons: i such models are inexpensive; ii they allow the understanding of local effects, which are difficult to measure accurately physically, and iii they can be used to generate extensive parametric studies. This paper presents a three-dimensional finite element model using ABAQUS software in order to identify the effect of different parameters on the behaviour of semi rigid steel beam to column end plate connections. Contact and sliding between different elements, bolt pretension and geometric and material non-linearity are included in this model. A parametric study is conducted using a model of two end-plate configurations: flush and extended end plates. The studied parameters were as follows: bolts type, end plate thickness and column web stiffener. Then, the model was calibrated and validated with experimental results taken from the literature and with the model proposed by Eurocode3. The procedure for determining the moment–rotation curve using finite element analysis is also given together with a brief explanation of how the design moment resistance and the initial rotational stiffness of the joint are obtained.

  7. Nonlinear static analysis of steel frames with semi rigid beam to column connections using cruciform element

    Directory of Open Access Journals (Sweden)

    Vahid Reza Afkhami

    2017-12-01

    Full Text Available In the steel frames, beam-column connections are traditionally assumed to be rigid or pinned, but in the steel frames, most types of beam-column connections are semi-rigid. Recent studies and some new codes, especially EC3 and EC4, include methods and formulas to estimate the resistance and stiffness of the panel zone. Because of weaknesses of EC3 and EC4 in some cases, Bayo et al.  proposed a new component-based method (cruciform element method to model internal and external semi-rigid connections that revived and modified EC methods. The nonlinear modelling of structures plays an important role in the analysis and design of structures and nonlinear static analysis is a rather simple and efficient technique for analysis of structures. This paper presents nonlinear static (pushover analysis technique by new nonlinearity factor and Bayo et al. model of two types of semi-rigid connections, end plate connection and top and seat angles connection. Two types of lateral loading, uniform and triangular distributions are considered.  Results show that the frames with top and seat angles connection have fewer initial stiffness than frames with semi-rigid connection and P-Δ effect more decreases base shear capacity in the case of top and seat angles connection. P-Δ effect in decrease of base shear capacity increases with the increase of number of stories.

  8. Analytical Study of Common Rigid Steel Connections under the Effect of Heat

    Directory of Open Access Journals (Sweden)

    Rohola Rahnavard

    2014-01-01

    Full Text Available One of the most important members of steel structure’s connection region is beam-to-column connection. Rigid connection in steel moment frame has special role in the behavior of these structures and the fire resistance of these connections can be important. In this paper the behaviors of three common types of rigid connections in Iran under the effect of heat were studied by the use of numerical finite element methods through ABAQUS software. The models were verified by the use of an experimental model through elastic and plastic amplitudes up to collapse and during numerical results, and the effect of large deformation in the nonlinear region has also been considered. The results show that the connection with the end plate had a better performance against heat than other connections. Also reduced stiffness and lateral buckling in this connection were less than other connections.

  9. Stability Analysis Of 3-d Conventional Pallet Rack Structures With Semi-rigid Connections

    Directory of Open Access Journals (Sweden)

    Kamal M. Bajoria

    2009-12-01

    Full Text Available This paper describe the three dimensional finite element modeling and buckling analysis of conventional pallet racking system with semi rigid connection. In this study three dimensional models of conventional pallet racking system were prepared using the finiteelement program ANSYS and finite element analysis carried out on conventional pallet racks with the 18 types of column sections developed along with semi-rigid connections. A parametric study was carried out to compare the effective length approach and the finiteelement method for accuracy and appropriateness for cold-formed steel frame design. Numerous frame elastic buckling analyses were carried out to evaluate the alignment chart and the AISI torsional-flexural buckling provisions. The parameters that influence the valueof Kx for column flexural buckling were examined in this study. The alignment chart and the AISI torsional-flexural buckling provisions, used to obtain the effective lengths and elastic buckling load of members were also evaluated. Results showed that the elastic buckling load obtained from the AISI torsional-flexural buckling provisions is generally conservative compared to the results obtained from performing frame elastic buckling analysis. Results also showed that, the effective length approach is more conservative than the finite element approach.

  10. Wave energy absorption by a submerged air bag connected to a rigid float

    DEFF Research Database (Denmark)

    Kurniawan, Adi; Chaplin, J. R.; Hann, M. R.

    2017-01-01

    A new wave energy device features a submerged ballasted air bag connected at the top to a rigid float. Under wave action, the bag expands and contracts, creating a reciprocating air flow through a turbine between the bag and another volume housed within the float. Laboratory measurements are gene......A new wave energy device features a submerged ballasted air bag connected at the top to a rigid float. Under wave action, the bag expands and contracts, creating a reciprocating air flow through a turbine between the bag and another volume housed within the float. Laboratory measurements...

  11. Almost Poisson integration of rigid body systems

    International Nuclear Information System (INIS)

    Austin, M.A.; Krishnaprasad, P.S.; Li-Sheng Wang

    1993-01-01

    In this paper we discuss the numerical integration of Lie-Poisson systems using the mid-point rule. Since such systems result from the reduction of hamiltonian systems with symmetry by lie group actions, we also present examples of reconstruction rules for the full dynamics. A primary motivation is to preserve in the integration process, various conserved quantities of the original dynamics. A main result of this paper is an O(h 3 ) error estimate for the Lie-Poisson structure, where h is the integration step-size. We note that Lie-Poisson systems appear naturally in many areas of physical science and engineering, including theoretical mechanics of fluids and plasmas, satellite dynamics, and polarization dynamics. In the present paper we consider a series of progressively complicated examples related to rigid body systems. We also consider a dissipative example associated to a Lie-Poisson system. The behavior of the mid-point rule and an associated reconstruction rule is numerically explored. 24 refs., 9 figs

  12. An investigation on the effect of gusset plate connection rigidity on the seismic behavior of special concentrically braced frames

    Directory of Open Access Journals (Sweden)

    Ali Esnaashari

    2016-12-01

    Full Text Available Special concentrically braced frames (SCBFs are commonly used to resist lateral loads in buildings. The bracing system sustains large deformations due to inelastic behavior in bracing members (buckling and yielding in tension. Generally, in the conventional modeling strategy, the effect of gusset plates in providing beam-column connections rigidity and hence, improving the post-buckling performance of these frames is not taken into account. This paper deals with the effect of gusset plate rigidity on the seismic behavior of SCBFs using Roeder’s proposed model in the literature. In this paper, four 3, 6, 9 and 12-story SCBFs were designed and modeled using two distinct methods: conventional method with hinged connections and Roeder’s method with semi-rigid connections. Then, the models behavior was investigated with both pushover analysis and nonlinear time-history analysis using OpenSees software. The results showed that lateral load capacity of the frames modeled with the Roeder’s proposed model are about 10% larger than the conventional method’s capacity. Also, it was found that the semi-rigid model leads to a less drift ratios and more overstrength factors.

  13. Evaluating a steel beam’s rigid connection to a concrete filled tubular column when submitted to dynamic load

    Directory of Open Access Journals (Sweden)

    Maritza Uribe Vallejo

    2009-01-01

    Full Text Available Using prequalified connections during the structural design stage becomes increasingly necessary when developing structural en-gineering projects which include steel elements; this is so that the steel elements’ appropriate behavior can be ensured according to the structural system and seismic demand. Unfortunately, the international entities providing this type of information (i.e. FEMA only have a limit series of prequalified connections and such series do not include rigid connections between steel beams and concrete filled tubular (CFT columns having an extended end plate, which has become a very widespread building practice in Colombia. This paper describes the most important aspects of a study at the Universidad Nacional de Colombia concerning the behavior of a steel beam rigidly connected to a CFT-column, using six physical models having different width-thickness ratio (b/t columns. ANSYS v.10 software was used for studying theoretical models (finite elements analysis for comparative analysis of cyclic test theoretical and experimental results for each specimen presented for the qualification phase. The six tested specimens’ hysteretic curves are presented. Several conclusions are drawn concerning finite element validation for this type of connection and the influence of width-thickness ratio (b/t variation and design recommendations for suitable behavior under dynamic loads when this type of connection was used.

  14. Dynamical analysis of an orbiting three-rigid-body system

    Energy Technology Data Exchange (ETDEWEB)

    Pagnozzi, Daniele, E-mail: daniele.pagnozzi@strath.ac.uk, E-mail: james.biggs@strath.ac.uk; Biggs, James D., E-mail: daniele.pagnozzi@strath.ac.uk, E-mail: james.biggs@strath.ac.uk [Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow, Scotland (United Kingdom)

    2014-12-10

    The development of multi-joint-spacecraft mission concepts calls for a deeper understanding of their nonlinear dynamics to inform and enhance system design. This paper presents a study of a three-finite-shape rigid-body system under the action of an ideal central gravitational field. The aim of this paper is to gain an insight into the natural dynamics of this system. The Hamiltonian dynamics is derived and used to identify relative attitude equilibria of the system with respect to the orbital reference frame. Then a numerical investigation of the behaviour far from the equilibria is provided using tools from modern dynamical systems theory such as energy methods, phase portraits and Poincarè maps. Results reveal a complex structure of the dynamics as well as the existence of connections between some of the equilibria. Stable equilibrium configurations appear to be surrounded by very narrow regions of regular and quasi-regular motions. Trajectories evolve on chaotic motions in the rest of the domain.

  15. High precision NC lathe feeding system rigid-flexible coupling model reduction technology

    Science.gov (United States)

    Xuan, He; Hua, Qingsong; Cheng, Lianjun; Zhang, Hongxin; Zhao, Qinghai; Mao, Xinkai

    2017-08-01

    This paper proposes the use of dynamic substructure method of reduction of order to achieve effective reduction of feed system for high precision NC lathe feeding system rigid-flexible coupling model, namely the use of ADAMS to establish the rigid flexible coupling simulation model of high precision NC lathe, and then the vibration simulation of the period by using the FD 3D damper is very effective for feed system of bolt connection reduction of multi degree of freedom model. The vibration simulation calculation is more accurate, more quickly.

  16. Connected motorcycle system performance.

    Science.gov (United States)

    2016-01-15

    This project characterized the performance of Connected Vehicle Systems (CVS) on motorcycles based on two key components: global positioning and wireless communication systems. Considering that Global Positioning System (GPS) and 5.9 GHz Dedicated Sh...

  17. The effect of rigid and non-rigid connections between implants and teeth on biological and technical complications: a systematic review and a meta-analysis.

    Science.gov (United States)

    Tsaousoglou, Phoebus; Michalakis, Konstantinos; Kang, Kiho; Weber, Hans-Peter; Sculean, Anton

    2017-07-01

    To assess survival, as well as technical and biological complication rates of partial fixed dental prostheses (FDPs) supported by implants and teeth. An electronic Medline search was conducted to identify articles, published in dental journals from January 1980 to August 2015, reporting on partial FDPs supported by implants and teeth. The search terms were categorized into four groups comprising the PICO question. Manual searches of published full-text articles and related reviews were also performed. The initial database search produced 3587 relevant titles. Three hundred and eighty-six articles were retrieved for abstract review, while 39 articles were selected for full-text review. A total of 10 studies were selected for inclusion. Overall survival rate for implants ranged between 90% and 100%, after follow-up periods with a mean range of 18-120 months. The survival of the abutment teeth was 94.1-100%, while the prostheses survival was 85-100% for the same time period. The most frequent complications were "periapical lesions" (11.53%). The most frequent technical complication was "porcelain occlusal fracture" (16.6%), followed by "screw loosening" (15%). According to the meta-analysis, no intrusion was noted on the rigid connection group, while five teeth (8.19%) were intruded in the non-rigid connection group [95% CI (0.013-0.151)]. The tooth-implant FDP seems to be a possible alternative to an implant-supported FDP. There is limited evidence that rigid connection between teeth and implants presents better results when compared with the non-rigid one. The major drawback of non-rigidly connected FDPs is tooth intrusion. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Wave energy absorption by a submerged air bag connected to a rigid float.

    Science.gov (United States)

    Kurniawan, A; Chaplin, J R; Hann, M R; Greaves, D M; Farley, F J M

    2017-04-01

    A new wave energy device features a submerged ballasted air bag connected at the top to a rigid float. Under wave action, the bag expands and contracts, creating a reciprocating air flow through a turbine between the bag and another volume housed within the float. Laboratory measurements are generally in good agreement with numerical predictions. Both show that the trajectory of possible combinations of pressure and elevation at which the device is in static equilibrium takes the shape of an S. This means that statically the device can have three different draughts, and correspondingly three different bag shapes, for the same pressure. The behaviour in waves depends on where the mean pressure-elevation condition is on the static trajectory. The captured power is highest for a mean condition on the middle section.

  19. Energy storage connection system

    Science.gov (United States)

    Benedict, Eric L.; Borland, Nicholas P.; Dale, Magdelena; Freeman, Belvin; Kite, Kim A.; Petter, Jeffrey K.; Taylor, Brendan F.

    2012-07-03

    A power system for connecting a variable voltage power source, such as a power controller, with a plurality of energy storage devices, at least two of which have a different initial voltage than the output voltage of the variable voltage power source. The power system includes a controller that increases the output voltage of the variable voltage power source. When such output voltage is substantially equal to the initial voltage of a first one of the energy storage devices, the controller sends a signal that causes a switch to connect the variable voltage power source with the first one of the energy storage devices. The controller then causes the output voltage of the variable voltage power source to continue increasing. When the output voltage is substantially equal to the initial voltage of a second one of the energy storage devices, the controller sends a signal that causes a switch to connect the variable voltage power source with the second one of the energy storage devices.

  20. Modeling of a light elastic beam by a system of rigid bodies

    Directory of Open Access Journals (Sweden)

    Šalinić Slaviša

    2004-01-01

    Full Text Available This paper has shown that a light elastic beam, in the case of small elastic deformations, can be modeled by a kinematic chain without branching composed of rigid bodies which are connected by passive revolute or prismatic joints with corresponding springs in them. Elastic properties of the beam are modeled by the springs introduced. The potential energy of the elastic beam is expressed as a function of components of the vector of elastic displacement and the vector of elastic rotation calculated for the elastic centre of the beam, which results in the diagonal stiffness matrix of the beam. As the potential energy of the introduced system of bodies with springs is expressed in the function of relative joint displacements, the diagonal stiffness matrix is obtained. In addition, these two stiffness matrices are equal. The modeling process has been demonstrated on the example of an elastic beam rotating about a fixed vertical axis, with a rigid body whose mass is considerably larger than the beam mass fixed to its free end. Differential equations of motion have been formed for this mechanical system. The modeling technique described here aims at expanding of usage of well developed methods of dynamics of systems of rigid bodies to the analysis of systems with elastic bodies. .

  1. Collisions of Constrained Rigid Body Systems with Friction

    Directory of Open Access Journals (Sweden)

    Haijun Shen

    1998-01-01

    Full Text Available A new approach is developed for the general collision problem of two rigid body systems with constraints (e.g., articulated systems, such as massy linkages in which the relative tangential velocity at the point of contact and the associated friction force can change direction during the collision. This is beyond the framework of conventional methods, which can give significant and very obvious errors for this problem, and both extends and consolidates recent work. A new parameterization and theory characterize if, when and how the relative tangential velocity changes direction during contact. Elastic and dissipative phenomena and different values for static and kinetic friction coefficients are included. The method is based on the explicitly physical analysis of events at the point of contact. Using this method, Example 1 resolves (and corrects a paradox (in the literature of the collision of a double pendulum with the ground. The method fundamentally subsumes other recent models and the collision of rigid bodies; it yields the same results as conventional methods when they would apply (Example 2. The new method reformulates and extends recent approaches in a completely physical context.

  2. Dynamic Multi-Rigid-Body Systems with Concurrent Distributed Contacts: Theory and Examples

    International Nuclear Information System (INIS)

    TRINKLE, JEFFREY C.; TZITZOURIS, J.A.; PANG, J.S.

    2001-01-01

    Consider a system of rigid bodies with multiple concurrent contacts. The multi-rigid-body contact problem is to predict the accelerations of the bodies and the normal friction loads acting at the contacts. This paper presents theoretical results for the multi-rigid-body contact problem under the assumptions that one or more contacts occur over locally planar, finite regions and that friction forces are consistent with the maximum work inequality. Existence and uniqueness results are presented for this problem under mild assumptions on the system inputs. In addition, the performance of two different time-stepping methods for integrating the dynamics are compared on two simple multi-body systems

  3. Three-dimensional formulation of rigid-flexible multibody systems with flexible beam elements

    International Nuclear Information System (INIS)

    Garcia-Vallejo, D.; Mayo, J.; Escalona, J. L.; Dominguez, J.

    2008-01-01

    Multibody systems generally contain solids with appreciable deformations and which decisively influence the dynamics of the system. These solids have to be modeled by means of special formulations for flexible solids. At the same time, other solids are of such a high stiffness that they may be considered rigid, which simplifies their modeling. For these reasons, for a rigid-flexible multibody system, two types of formulations coexist in the equations of the system. Among the different possibilities provided in the literature on the material, the formulation in natural coordinates and the formulation in absolute nodal coordinates are utilized in this paper to model the rigid and flexible solids, respectively. This paper contains a mixed formulation based on the possibility of sharing coordinates between a rigid solid and a flexible solid. The global mass matrix of the system is shown to be constant and, in addition, many of the constraint equations obtained upon utilizing these formulations are linear and can be eliminated

  4. Biomimetic model systems of rigid hair beds: Part II - Experiment

    Science.gov (United States)

    Jammalamadaka, Mani S. S.; Hood, Kaitlyn; Hosoi, Anette

    2017-11-01

    Crustaceans - such as lobsters, crabs and stomapods - have hairy appendages that they use to recognize and track odorants in the surrounding fluid. An array of rigid hairs impedes flow at different rates depending on the spacing between hairs and the Reynolds number, Re. At larger Reynolds number (Re>1), fluid travels through the hairs rather than around them, a phenomenon called leakiness. Crustaceans flick their appendages at different speeds in order to manipulate the leakiness between the hairs, allowing the hairs to either detect the odors in a sample of fluid or collect a new sample. Theoretical and numerical studies predict that there is a fast flow region near the hairs that moves closer to the hairs as Re increases. Here, we test this theory experimentally. We 3D printed rigid hairs with an aspect ratio of 30:1 in rectangular arrays with different hair packing fractions. We custom built an experimental setup which establishes poiseuille flow at intermediate Re, Re <=200. We track the flow dynamics through the hair beds using tracer particles and Particle Imaging Velocimetry. We will then compare the modelling predictions with the experimental outcomes.

  5. Composite Sliding Mode Control for a Free-Floating Space Rigid-Flexible Coupling Manipulator System

    OpenAIRE

    Congqing, Wang; Pengfei, Wu; Xin, Zhou; Xiwu, Pei

    2013-01-01

    The flexible space manipulator is a highly nonlinear and coupled dynamic system. This paper proposes a novel composite sliding mode control to deal with the vibration suppression and trajectory tracking of a free-floating space rigid-flexible coupling manipulator with a rigid payload. First, the dynamic equations of this system are established by using Lagrange and assumed mode methods and in the meantime this dynamic modelling allows consideration of the modelling errors, the external distur...

  6. CODAC systems arrangement and connectivity

    Energy Technology Data Exchange (ETDEWEB)

    Gulati, Hitesh Kumar, E-mail: hkgulati@gmail.com; Beltran, David; Kuehn, Ingo; Kotamaki, Miikka; Makijarvi, Petri; Wallander, Anders

    2013-10-15

    Highlights: •The CODAC system is a distributed system and scattered in many buildings connected with cables. Building construction for ITER project is just started so volume reservation for different CODAC component is done based on the content of this paper. •The 2-D and 3-D diagrams have been prepared which are showing the location of different CODAC equipment and their connectivity. •The different requirements regarding raised access (false) floor, power requirements, heat load, installation, maintenance, redundancy, and segregation etc. have been considered. -- Abstract: The CODAC system is responsible for integrating all ITER plant system Instrumentation and Control systems and enabling operation of ITER machine as a single integrated facility. The different ITER plant systems and their Instrumentation and Control systems are distributed in several ITER buildings on the ITER platform. The CODAC systems have to interface with all these distributed plant system I and C systems. CODAC systems will be composed of several physical systems or components like networks, servers, workstations (terminals), large displays, PSH, storage systems etc. Several rooms in different buildings have been defined to house all above equipment. The site-wide CODAC network infrastructure will be based on a dual (redundant) star topology. The two redundant star points will house the core networking switches. These redundant core switches will be installed in different buildings. Cubicles used for network infrastructure are distributed among “hutches,” where a CODAC hutch is a room or area equipped with appropriate heating, ventilation, air conditioning and uninterruptible power which will be directly connected through two star points. The responsibility of CODAC infrastructure ends up to the plant system I and C cubicles so several passive CODAC network panels have identified in all I and C rooms of different plant buildings. This CODAC Network Panel will be the physical

  7. Biomimetic model systems of rigid hair beds: Part I - Theory

    Science.gov (United States)

    Hood, Kaitlyn; Jammalamadaka, Mani S. S.; Hosoi, Anette

    2017-11-01

    Crustaceans - such as lobsters, crabs, and stomapods - have hairy appendages that they use to recognize and track odorants in the surrounding fluid. An array of rigid hairs impedes flow at different rates depending on the spacing between hairs and the Reynolds number, Re. At larger Reynolds numbers (Re >1), fluid travels through the hairs rather than around them, a phenomenon called leakiness. Crustaceans flick their appendages at different speeds in order to manipulate the leakiness between the hairs, allowing the hairs to either detect odors in a sample of fluid or collect a new sample. A single hair can be represented as a slender body attached at one end to a wall. Using both slender body theory and numerical methods, we observe that there is a region of flow around the hair that speeds up relative to the unobstructed flow. As the Reynolds number increases, this fast flow region moves closer to the hair. Using this model, we predict that an array of hairs can be engineered to have a desired leakiness profile.

  8. Topology Optimization of a Vibrating System of Rigid and Flexible Bodies for Maximizing Repeated Eigenfrequencies

    International Nuclear Information System (INIS)

    Ahn, Byungseong; Kim, Suh In; Kim, Yoon Young

    2016-01-01

    When a system consisting of rigid and flexible bodies is optimized to improve its dynamic characteristics, its eigenfrequencies are typically maximized. While topology optimization formulations dealing with simultaneous design of a system of rigid and flexible bodies are available, studies on eigenvalue maximization of the system are rare. In particular, no work has solved for the case when the target frequency becomes one of the repeated eigenfrequencies. The problem involving repeated eigenfrequencies is solved in this study, and a topology optimization formulation and sensitivity analysis are presented. Further, several numerical case studies are considered to demonstrate the validity of the proposed formulation

  9. Rheology of multiphase polymer systems using novel "melt rigidity" evaluation approach

    Science.gov (United States)

    Kracalik, Milan

    2015-04-01

    Multiphase polymer systems like blends, composites and nanocomposites exhibit complex rheological behaviour due to physical and also possibly chemical interactions between individual phases. Up to now, rheology of heterogeneous polymer systems has been usually described by evaluation of viscosity curve (shear thinning phenomenon), storage modulus curve (formation of secondary plateau) or plotting information about damping behaviour (e.g. Van Gurp-Palmen-plot). On the contrary to evaluation of damping behaviour, "melt rigidity" approach has been introduced for description of physical network of rigid particles in polymer matrix as relation of ∫G'/∫G" over specific frequency range. This approach has been experimentally proved for polymer nanocomposites in order to compare shear flow characteristics with elongational flow field. In this contribution, LDPE-clay nanocomposites with different dispersion grades (physical networks) have been prepared and characterized by both conventional as well as novel "melt rigidity" approach.

  10. Hamiltonian Dynamics of Spider-Type Multirotor Rigid Bodies Systems

    International Nuclear Information System (INIS)

    Doroshin, Anton V.

    2010-01-01

    This paper sets out to develop a spider-type multiple-rotor system which can be used for attitude control of spacecraft. The multirotor system contains a large number of rotor-equipped rays, so it was called a 'Spider-type System', also it can be called 'Rotary Hedgehog'. These systems allow using spinups and captures of conjugate rotors to perform compound attitude motion of spacecraft. The paper describes a new method of spacecraft attitude reorientation and new mathematical model of motion in Hamilton form. Hamiltonian dynamics of the system is investigated with the help of Andoyer-Deprit canonical variables. These variables allow obtaining exact solution for hetero- and homoclinic orbits in phase space of the system motion, which are very important for qualitative analysis.

  11. The connection of the interplanetary magnetic field turbulence and rigidity spectrum of Forbush decrease of the galactic cosmic ray intensity

    International Nuclear Information System (INIS)

    Wawrzynczak, A; Alania, M V

    2015-01-01

    We analyze the temporal changes in the rigidity spectrum of Forbush decrease (Fd) of the galactic cosmic ray (GCR) intensity observed in November 2004. We compute the rigidity spectrum in two energy ranges based on the daily data from the worldwide network of neutron monitors and Nagoya ground muon telescope. We demonstrate that the changes in the rigidity spectrum of Fd are linked to the evolution/decay of the interplanetary magnetic field (IMF) turbulence during various phases of the Fd. We analyze the time-evolution of the state of the turbulence of the IMF in various frequency ranges during the Fd. Performed analysis show that the decrease of the exponent ν of the Power Spectral Density (PSD ∝ f −ν , where f is frequency) of the IMF turbulence with decreasing frequency lead to the soft rigidity spectrum of Fd for GCR particles with relatively higher energies. (paper)

  12. Rigid hoist articulated grapple system development for enhanced remote maintenance

    International Nuclear Information System (INIS)

    Witham, C.; White, P.; Garin, J.

    1979-01-01

    Remote maintenance and repair within nuclear environments have become more demanding of remote manipulation equipment in the last few years. A deficiency exists in the array of tools available for dexterous operations of loads in the 180-kg range. The development of a manipulation system with enhanced operator controls is discussed. This system is a six-degree-of-freedom manipulator with bilateral servo control. It is to be attached to a mobile support boom in order to operate throughout the nuclear cell. The manipulator is intended to work in conjunction with light duty servomanipulators, overhead crane systems, and through-the-wall mechanical master slaves

  13. Linking rigid multibody systems via controllable thin fluid films

    DEFF Research Database (Denmark)

    Estupinan, Edgar Alberto; Santos, Ilmar

    2009-01-01

    , this paper gives a theoretical contribution to the combined fields of fluid–structure interaction and vibration control. The methodology is applied to a reciprocating linear compressor, where the dynamics of the mechanical components are described with help of multibody dynamics. The crank is linked......This work deals with the mathematical modelling of multibody systems interconnected via thin fluid films. The dynamics of the fluid films can be actively controlled by means of different types of actuators, allowing significant vibration reduction of the system components. In this framework...... to the rotor via a thin fluid film, where the hydrodynamic pressure is described by the Reynolds equation, which is modified to accommodate the controllable lubrication conditions. The fluid film forces are coupled to the set of nonlinear equations that describes the dynamics of the reciprocating linear...

  14. Rapid maxillary distraction protocol utilizing the halo distraction system and rigid internal fixation.

    Science.gov (United States)

    Baker, Stephen B; Reid, Russell R; Burkey, Brooke; Bartlett, Scott P

    2007-09-01

    To shorten head frame wear time associated with external halo distraction (HD), we have adapted a protocol for maxillary distraction with the halo system that integrates plate fixation. All patients had a history of cleft lip and/or palate and maxillary retrusion > or = 8 mm. Five patients treated with this protocol and followed for at least 1 year were included in this study. The protocol included a 3-day latency period, variable maxillary distraction, and removal of the halo device with simultaneous rigid internal fixation. Two patients had a variable period of maxillomandibular fixation (MMF), which maintained the maxillary advancement and idealized intercuspal position while permitting further callus maturation. Cephalographs were obtained preoperatively, immediately following distractor removal, and 1 year after rigid internal fixation. The mean age at time of surgery was 18.7 years. The maxillary deficiency ranged from 8 to 15 mm (mean = 10.6 mm). All five patients demonstrated excellent occlusion. Cephalometric analysis 1-year post rigid internal fixation revealed minimal (maxillary distraction followed by MMF to maintain maxillary advancement may reduce halo device wear to 1 to 2 weeks. MMF optimizes occlusion by forcing the maxillary teeth into maximal intercuspal position. Rigid fixation is not only associated with less long-term relapse compared to nonrigid forms of fixation, but also minimizes the incidence of nonunion. This treatment protocol provides the advancement possible with distraction osteogenesis and the accuracy of orthognathic surgery, thereby minimizing external head frame wear.

  15. Analytic analysis of auxetic metamaterials through analogy with rigid link systems

    OpenAIRE

    Rayneau-Kirkhope, Daniel; Zhang, Chengzhao; Theran, Louis; Dias, Marcelo A.

    2017-01-01

    Recent progress in advanced additive manufacturing techniques has stimulated the growth of the field of mechanical metamaterials. One area particular interest in this subject is the creation of auxetic material properties through elastic instability. This paper focuses on a novel methodology in the analysis of auxetic metamaterials through analogy with rigid link lattice systems. Our analytic methodology gives extremely good agreement with finite element simulations for both the onset of elas...

  16. Analytic analysis of auxetic metamaterials through analogy with rigid link systems

    Science.gov (United States)

    Rayneau-Kirkhope, Daniel; Zhang, Chengzhao; Theran, Louis; Dias, Marcelo A.

    2018-02-01

    In recent years, many structural motifs have been designed with the aim of creating auxetic metamaterials. One area of particular interest in this subject is the creation of auxetic material properties through elastic instability. Such metamaterials switch from conventional behaviour to an auxetic response for loads greater than some threshold value. This paper develops a novel methodology in the analysis of auxetic metamaterials which exhibit elastic instability through analogy with rigid link lattice systems. The results of our analytic approach are confirmed by finite-element simulations for both the onset of elastic instability and post-buckling behaviour including Poisson's ratio. The method gives insight into the relationships between mechanisms within lattices and their mechanical behaviour; as such, it has the potential to allow existing knowledge of rigid link lattices with auxetic paths to be used in the design of future buckling-induced auxetic metamaterials.

  17. Simple clamped connection for bamboo truss systems

    NARCIS (Netherlands)

    Blok, R.

    2016-01-01

    “How to make fast and simple tension connections for truss systems?” The Solution: The innovation is a connection that uses only widely available base components (boltsand threaded steel bars) and simple hand tools to install it. With a handsaw and aspanner, the bamboo stems can be combined into to

  18. Cross-Linked Liquid Crystalline Systems From Rigid Polymer Networks to Elastomers

    CERN Document Server

    Broer, Dirk

    2011-01-01

    With rapidly expanding interest in liquid crystalline polymers and elastomers among the liquid crystal community, researchers are currently exploring the wide range of possible application areas for these unique materials, including optical elements on displays, tunable lasers, strain gauges, micro-structures, and artificial muscles. Written by respected scientists from academia and industry around the world, who are not only active in the field but also well-known in more traditional areas of research, "Cross-Linked Liquid Crystalline Systems: From Rigid Polymer Networks to Elastomers&qu

  19. Simulating coupled dynamics of a rigid-flexible multibody system and compressible fluid

    Science.gov (United States)

    Hu, Wei; Tian, Qiang; Hu, HaiYan

    2018-04-01

    As a subsequent work of previous studies of authors, a new parallel computation approach is proposed to simulate the coupled dynamics of a rigid-flexible multibody system and compressible fluid. In this approach, the smoothed particle hydrodynamics (SPH) method is used to model the compressible fluid, the natural coordinate formulation (NCF) and absolute nodal coordinate formulation (ANCF) are used to model the rigid and flexible bodies, respectively. In order to model the compressible fluid properly and efficiently via SPH method, three measures are taken as follows. The first is to use the Riemann solver to cope with the fluid compressibility, the second is to define virtual particles of SPH to model the dynamic interaction between the fluid and the multibody system, and the third is to impose the boundary conditions of periodical inflow and outflow to reduce the number of SPH particles involved in the computation process. Afterwards, a parallel computation strategy is proposed based on the graphics processing unit (GPU) to detect the neighboring SPH particles and to solve the dynamic equations of SPH particles in order to improve the computation efficiency. Meanwhile, the generalized-alpha algorithm is used to solve the dynamic equations of the multibody system. Finally, four case studies are given to validate the proposed parallel computation approach.

  20. Simulating Dynamics of the System of Articulated Rigid Bodies with Joint Friction

    Directory of Open Access Journals (Sweden)

    M. V. Michaylyuk

    2016-01-01

    Full Text Available The subject of the work is to simulate dynamics of the system of articulated rigid bodies in the virtual environment complexes. The work aim is to develop algorithms and methods to simulate the multi-body system dynamics with joint friction to ensure all calculations in real time in line with visual realistic behavior of objects in a scene.The paper describes the multibody system based on a maximal set of coordinates, and to simulate the joint friction is used a Coulomb's law of dry friction. Joints are described using the holonomic constraints and their derivatives that specify the constraints on velocities of joined bodies. Based on The Coulomb’s law a correlation for the friction impulse values has been derived as an inequality. If the friction impulse performs a constraint that is a lack of relative motion of two joint-joined bodies, there is a static friction in the joint. Otherwise, there is a dynamic friction in the joint. Using a semi-implicit Euler method allows us to describe dynamics of articulated rigid bodies with joint friction as a system of linear algebraic equations and inequalities for the unknown velocities and impulse values.To solve the obtained system of equations and inequalities is used an iterative method of sequential impulses, which sequentially processes constraints for each joint with impulse calculation and its application to the joined bodies rather than considers the entire system. To improve the method convergence, at each iteration the calculated impulses are accumulated for their further using as an initial approximation at the next step of simulation.The proposed algorithms and methods have been implemented in the training complex dynamics subsystem, developed in SRISA RAS. Evaluation of these methods and algorithms has demonstrated their full adequacy to requirements for virtual environment systems and training complexes.

  1. Rigid-flexible coupling dynamics of three-dimensional hub-beams system

    International Nuclear Information System (INIS)

    Liu Jinyang; Lu Hao

    2007-01-01

    In the previous research of the coupling dynamics of a hub-beam system, coupling between the rotational motion of hub and the torsion deformation of beam is not taken into account since the system undergoes planar motion. Due to the small longitudinal deformation, coupling between the rotational motion of hub and the longitudinal deformation of beam is also neglected. In this paper, rigid-flexible coupling dynamics is extended to a hub-beams system with three-dimensional large overall motion. Not only coupling between the large overall motion and the bending deformation, but also coupling between the large overall motion and the torsional deformation are taken into account. In case of temperature increase, the longitudinal deformation caused by the thermal expansion is significant, such that coupling between the large overall motion and the longitudinal deformation is also investigated. Combining the characteristics of the hybrid coordinate formulation and the absolute nodal coordinate formulation, the system generalized coordinates include the relative nodal displacement and the slope of each beam element with respect to the body-fixed frame of the hub, and the variables related to the spatial large overall motion of the hub and beams. Based on precise strain-displacement relation, the geometric stiffening effect is taken into account, and the rigid-flexible coupling dynamic equations are derived using velocity variational principle. Finite element method is employed for discretization. Simulation of a hub-beams system is used to show the coupling effect between the large overall motion and the torsional deformation as well as the longitudinal deformation. Furthermore, conservation of energy in case of free motion is shown to verify the formulation

  2. A Linear Active Disturbance Rejection Control for a Ball and Rigid Triangle System

    Directory of Open Access Journals (Sweden)

    Carlos Aguilar-Ibanez

    2016-01-01

    Full Text Available This paper proposes an application of linear flatness control along with active disturbance rejection control (ADRC for the local stabilization and trajectory tracking problems in the underactuated ball and rigid triangle system. To this end, an observer-based linear controller of the ADRC type is designed based on the flat tangent linearization of the system around its corresponding unstable equilibrium rest position. It was accomplished through two decoupled linear extended observers and a single linear output feedback controller, with disturbance cancelation features. The controller guarantees locally exponentially asymptotic stability for the stabilization problem and practical local stability in the solution of the tracking error. An advantage of combining the flatness and the ADRC methods is that it possible to perform online estimates and cancels the undesirable effects of the higher-order nonlinearities discarded by the linearization approximation. Simulation indicates that the proposed controller behaves remarkably well, having an acceptable domain of attraction.

  3. Advanced connection systems for architectural glazing

    CERN Document Server

    Afghani Khoraskani, Roham

    2015-01-01

    This book presents the findings of a detailed study to explore the behavior of architectural glazing systems during and after an earthquake and to develop design proposals that will mitigate or even eliminate the damage inflicted on these systems. The seismic behavior of common types of architectural glazing systems are investigated and causes of damage to each system, identified. Furthermore, depending on the geometrical and structural characteristics, the ultimate horizontal load capacity of glass curtain wall systems is defined based on the stability of the glass components. Detailed attention is devoted to the incorporation of advanced connection devices between the structure of the building and the building envelope system in order to minimize the damage to glazed components. An innovative new connection device is introduced that results in a delicate and functional system easily incorporated into different architectural glazing systems, including those demanding maximum transparency.

  4. Radiological approach to systemic connective tissue diseases

    International Nuclear Information System (INIS)

    Wiesmann, W.; Schneider, M.

    1988-01-01

    Systemic lupus erythematosus (SLE) and progressive systemic sclerosis (PSS) represent the most frequent manifestations of systemic connective tissue diseases (collagen diseases). Radiological examinations are employed to estimate the extension and degree of the pathological process. In addition, progression of the disease can be verified. In both of the above collagen diseases, specific radiological findings can be observed that permit them to be differentiated from other entities. An algorithm for the adequate radiological work-up of collagen diseases is presented. (orig.) [de

  5. Radiological approach to systemic connective tissue diseases

    Energy Technology Data Exchange (ETDEWEB)

    Wiesmann, W; Schneider, M

    1988-07-01

    Systemic lupus erythematosus (SLE) and progressive systemic sclerosis (PSS) represent the most frequent manifestations of systemic connective tissue diseases (collagen diseases). Radiological examinations are employed to estimate the extension and degree of the pathological process. In addition, progression of the disease can be verified. In both of the above collagen diseases, specific radiological findings can be observed that permit them to be differentiated from other entities. An algorithm for the adequate radiological work-up of collagen diseases is presented.

  6. Generalized Predictive Control of Dynamic Systems with Rigid-Body Modes

    Science.gov (United States)

    Kvaternik, Raymond G.

    2013-01-01

    Numerical simulations to assess the effectiveness of Generalized Predictive Control (GPC) for active control of dynamic systems having rigid-body modes are presented. GPC is a linear, time-invariant, multi-input/multi-output predictive control method that uses an ARX model to characterize the system and to design the controller. Although the method can accommodate both embedded (implicit) and explicit feedforward paths for incorporation of disturbance effects, only the case of embedded feedforward in which the disturbances are assumed to be unknown is considered here. Results from numerical simulations using mathematical models of both a free-free three-degree-of-freedom mass-spring-dashpot system and the XV-15 tiltrotor research aircraft are presented. In regulation mode operation, which calls for zero system response in the presence of disturbances, the simulations showed reductions of nearly 100%. In tracking mode operations, where the system is commanded to follow a specified path, the GPC controllers produced the desired responses, even in the presence of disturbances.

  7. Indirect Inverse Substructuring Method for Multibody Product Transport System with Rigid and Flexible Coupling

    Directory of Open Access Journals (Sweden)

    Jun Wang

    2015-01-01

    Full Text Available The aim of this paper is to develop a new frequency response function- (FRF- based indirect inverse substructuring method without measuring system-level FRFs in the coupling DOFs for the analysis of the dynamic characteristics of a three-substructure coupled product transport system with rigid and flexible coupling. By enforcing the dynamic equilibrium conditions at the coupling coordinates and the displacement compatibility conditions, a closed-form analytical solution to inverse substructuring analysis of multisubstructure coupled product transport system is derived based on the relationship of easy-to-monitor component-level FRFs and the system-level FRFs at the coupling coordinates. The proposed method is validated by a lumped mass-spring-damper model, and the predicted coupling dynamic stiffness is compared with the direct computation, showing exact agreement. The method developed offers an approach to predict the unknown coupling dynamic stiffness from measured FRFs purely. The suggested method may help to obtain the main controlling factors and contributions from the various structure-borne paths for product transport system.

  8. Analysis of the Gyroscopic Stabilization of a System of Rigid Bodies

    DEFF Research Database (Denmark)

    Kliem, Wolfhard; Kliem, Wolfhard

    1996-01-01

    We study the gyroscopic of a three-body system. A new method offinding stability regions, based on mechanism and criteria for gyroscopicstabilization, is presented. Of particular interest in this connection isthe theory of interaction of eigenvalues. This leads to a complete 3-dimensionalanalysis......, which shows the regions of stability, divergence, and flutter ofa simple model of a rotating spaceship....

  9. Maxillary Distraction Osteogenesis in Unilateral Cleft Lip and Palate Patients with Rigid External Distraction System.

    Science.gov (United States)

    Alkhouri, Shadi; Waite, Peter D; Davis, Matthew B; Lamani, Ejvis; Kau, Chung How

    2017-01-01

    Distraction osteogenesis (DO) is a treatment option for patients with maxillary hypoplasia secondary to cleft lip and palate (CLP). The aim of this study is to present a technique for maxillary DO using Le Fort I osteotomy with rigid external distraction (RED) system. The patient presented in this paper was an Asian female with CLP aged 13 years and 6 months. She presented with severe midfacial deficiency with a Class III dental malocclusion with a negative overjet and concave facial profile. Cone-beam computed tomography images were recorded preoperatively and the operation performed involved a high Le Fort I osteotomy. The appliance fabricated was banded to upper first molars used for anchorage of the RED system. Distraction of the maxilla was initiated after 7-day latency period. Postoperative cephalometric analysis showed maxillary advancement anteriorly and superiorly, the total distraction treatment period was 10 days. The maxillary advancement was 10.5 mm and the SNA angle increased from 67.5° to 77.9°. Furthermore, the ANB angle changed from -9.8° to 1.6° and the occlusion changed from Class III to Class I. The profile of the face changed from concave to convex and a much better esthetic result was achieved. The study suggests RED system to be a reliable alternative procedure for the treatment of midfacial hypoplasia with or without cleft. Furthermore, it minimizes the risk of the surgical procedure and shortens the operating time.

  10. Fiber Optic Systems for Light Curing Rigidization of Inflatable Structures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Light (UV and visible) curing composite matrix resins are being explored as an attractive means for rigidizing inflatable spacecraft for large space-deployed...

  11. Design, development, and application of precast and prestressed concrete system for rigid pavement in Indonesia

    Science.gov (United States)

    Nurjaman, Hari; Faizal, Lutfi; Suaryana, Nyoman; Hariandja, Binsar; Gambiro, Purnomo, Wicaksono, Siswo

    2017-11-01

    The performance of highways in Indonesia until today is yet to be optimum. Flexible or rigid pavement construction generally do not reach designed service lives, either due to the fact that the construction do not meet specifications or unavoidable excessive load. Precast and prestressed concrete system has been applied since 2007, but unfortunately the application has not been optimum due to the fact that the construction method is not integrally carried out. This paper deals with a construction concept that developed in 2015-2017. The concept applies green construction based on integrated manufacture industry, starting from design, construction, function, maintenance and demolition. The concept is applied on the three highway sub-layers, i.e., sub grade, sub base, and surface, and drainage system. Sub grade improvement may use soil dislocation, chemical improvement or concrete matress. Sub base material uses foam mortar, which is material easy in quality control compared to conventional materials. Pavement material uses precast and prestressed concrete components with controlled quality, quickly function as flexible pavement, and moreover, may anticipate excessive loadings. Cost estimation is carried out integrated by life cycle cost: initial investment, obstruction while construction, and maintenance cost during operation. This innovation has passed tests in technical construction method aspects as well as construction work in 2015-2017, so it is available to support infrastructure construction acceleration which achieves quality demanded to date.

  12. Estimating the magnitude of steric effects in rigid systems by NMR

    International Nuclear Information System (INIS)

    Yoneda, Julliane Diniz; Seidl, Peter Rudolf; Leal, Katia Zaccur

    2008-01-01

    The rapid advance of supramolecular chemistry has led to a better understanding of the forces and interactions that are responsible for many different phenomena. Among these, steric effects play an important role in determining the constraints to association between the species involved. Although the role of steric effects has been recognized for a long time, quantitative information has been mainly related to the comparison of these effects on a chemical reaction or conformational equilibrium rather than the properties of the group of atoms that is responsible for their manifestation. This situation has been changing with the increase in power of computational methods and the accumulation of data on model compounds that can be used for the purpose of comparison. Here we present a short review of our recent work on NMR of rigid carbocyclic systems and apply this type of approach to di- and triamantane systems. Our results show how NMR can be used to locate the segment of a molecule that is subjected to steric effects and evaluate the degree to which these effects will distort its geometry. (author)

  13. Estimating the magnitude of steric effects in rigid systems by NMR

    Energy Technology Data Exchange (ETDEWEB)

    Yoneda, Julliane Diniz [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Programa Pos-Graduacao em Quimica Organica; Seidl, Peter Rudolf [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica; Leal, Katia Zaccur, E-mail: pseidl@eq.ufrj.br [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Fisico-Quimica. Programa de Pos-Graduacao em Quimica Organica

    2008-07-01

    The rapid advance of supramolecular chemistry has led to a better understanding of the forces and interactions that are responsible for many different phenomena. Among these, steric effects play an important role in determining the constraints to association between the species involved. Although the role of steric effects has been recognized for a long time, quantitative information has been mainly related to the comparison of these effects on a chemical reaction or conformational equilibrium rather than the properties of the group of atoms that is responsible for their manifestation. This situation has been changing with the increase in power of computational methods and the accumulation of data on model compounds that can be used for the purpose of comparison. Here we present a short review of our recent work on NMR of rigid carbocyclic systems and apply this type of approach to di- and triamantane systems. Our results show how NMR can be used to locate the segment of a molecule that is subjected to steric effects and evaluate the degree to which these effects will distort its geometry. (author)

  14. Rigidity and symmetry

    CERN Document Server

    Weiss, Asia; Whiteley, Walter

    2014-01-01

    This book contains recent contributions to the fields of rigidity and symmetry with two primary focuses: to present the mathematically rigorous treatment of rigidity of structures, and to explore the interaction of geometry, algebra, and combinatorics. Overall, the book shows how researchers from diverse backgrounds explore connections among the various discrete structures with symmetry as the unifying theme.  Contributions present recent trends and advances in discrete geometry, particularly in the theory of polytopes. The rapid development of abstract polytope theory has resulted in a rich theory featuring an attractive interplay of methods and tools from discrete geometry, group theory, classical geometry, hyperbolic geometry and topology.  The volume will also be a valuable source as an introduction to the ideas of both combinatorial and geometric rigidity theory and its applications, incorporating the surprising impact of symmetry. It will appeal to students at both the advanced undergraduate and gradu...

  15. Analysis of the gyroscopic stabilization of a system of rigid bodies

    DEFF Research Database (Denmark)

    Kliem, Wolfhard; Seyranian, Alexander P.

    1997-01-01

    We study the gyroscopic stability of a three-body system. A new method of finding stability regions, based on mechanism and criteria for gyroscopic stabilization, is presented. Of particular interest in this connection is the theory of interaction of eigenvalues. This leads to a complete 3......-dimensional analysis, which shows the regions of stability, divergence, and flutter of a simple model of a rotating spaceship....

  16. Grid-connected wind and photovoltaic system

    Science.gov (United States)

    Devabakthuni, Sindhuja

    The objective of this thesis is to design a grid connected wind and photovoltaic system. A new model of converter control was designed which maintains the voltage of the bus to grid as constant when combined system of solar and wind is connected to AC bus. The model is designed to track maximum power at each point irrespective of changes in irradiance, temperature and wind speed which affects the power supplied to grid. Solar power from the sun is not constant as it is affected by changes in irradiances and temperature. Even the wind power is affected by wind speed. A MPPT controller was designed for both systems. A boost converter is designed which uses the pulses from MPPT controller to boost the output. Wind system consists of wind turbine block from the MATLAB with a pitch angle controller to maintain optimum pitch angle. The output from wind turbine is connected to a permanent magnet synchronous generator. The unregulated DC output from the photovoltaic system is directly given to boost converter. The AC output from the wind system is given to an uncontrolled rectifier to get a unregulated DC output. The unregulated DC output goes to the boost converter. A voltage source inverter was designed which converts the rectified DC output from the boost converter to AC power. The inverter is designed to maintain constant AC bus voltage irrespective of the disturbances in the power supply. Photovoltaic and wind systems are individually designed for 5KW each in MATLAB-Simulink environment. In this thesis, the models were subjected to changes in irradiance, temperature and wind speed and the results were interpreted. The model was successful in tracking maximum at every instant and the AC bus voltage was maintained constant throughout the simulation.

  17. Dynamic Model and Vibration Power Flow of a Rigid-Flexible Coupling and Harmonic-Disturbance Exciting System for Flexible Robotic Manipulator with Elastic Joints

    Directory of Open Access Journals (Sweden)

    Yufei Liu

    2015-01-01

    Full Text Available This paper investigates the dynamic of a flexible robotic manipulator (FRM which consists of rigid driving base, flexible links, and flexible joints. With considering the motion fluctuations caused by the coupling effect, such as the motor parameters and mechanism inertias, as harmonic disturbances, the system investigated in this paper remains a parametrically excited system. An elastic restraint model of the FRM with elastic joints (FRMEJ is proposed, which considers the elastic properties of the connecting joints between the flexible arm and the driving base, as well as the harmonic disturbances aroused by the electromechanical coupling effect. As a consequence, the FRMEJ accordingly remains a flexible multibody system which conveys the effects of rigid-flexible couple and electromechanical couple. The Lagrangian function and Hamilton’s principle are used to establish the dynamic model of the FRMEJ. Based on the dynamic model proposed, the vibration power flow is introduced to show the vibration energy distribution. Numerical simulations are conducted to investigate the effect of the joint elasticities and the disturbance excitations, and the influences of the structure parameters and motion parameters on the vibration power flow are studied. The results obtained in this paper contribute to the structure design, motion optimization, and vibration control of FRMs.

  18. Connect Global Positioning System RF Module

    Science.gov (United States)

    Franklin, Garth W.; Young, Lawrence E.; Ciminera, Michael A.; Tien, Jeffrey Y.; Gorelik, Jacob; Okihiro, Brian Bachman; Koelewyn, Cynthia L.

    2012-01-01

    The CoNNeCT Global Positioning System RF Module (GPSM) slice is part of the JPL CoNNeCT Software Defined Radio (SDR). CoNNeCT is the Communications, Navigation, and Net working reconfigurable Testbed project that is part of NASA's Space Communication and Nav igation (SCaN) Program. The CoNNeCT project is an experimental dem onstration that will lead to the advancement of SDRs and provide a path for new space communication and navigation systems for future NASA exploration missions. The JPL CoNNeCT SDR will be flying on the International Space Station (ISS) in 2012 in support of the SCaN CoNNeCT program. The GPSM is a radio-frequency sampler module (see Figure 1) that directly sub-harmonically samples the filtered GPS L-band signals at L1 (1575.42 MHz), L2 (1227.6 MHz), and L5 (1176.45 MHz). The JPL SDR receives GPS signals through a Dorne & Margolin antenna mounted onto a choke ring. The GPS signal is filtered against interference, amplified, split, and fed into three channels: L1, L2, and L5. In each of the L-band channels, there is a chain of bandpass filters and amplifiers, and the signal is fed through each of these channels to where the GPSM performs a one-bit analog-to-digital conversion (see Figure 2). The GPSM uses a sub-harmonic, single-bit L1, L2, and L5 sampler that samples at a clock rate of 38.656 MHz. The new capability is the down-conversion and sampling of the L5 signal when previous hardware did not provide this capability. The first GPS IIF Satellite was launched in 2010, providing the new L5 signal. With the JPL SDR flying on the ISS, it will be possible to demonstrate navigation solutions with 10-meter 3-D accuracy at 10-second intervals using a field-program mable gate array (FPGA)-based feedback loop running at 50 Hz. The GPS data bits will be decoded and used in the SDR. The GPSM will also allow other waveforms that are installed in the SDR to demonstrate various GNSS tracking techniques.

  19. Experimental grid connected PV system power analysis

    Science.gov (United States)

    Semaoui, Smail; Abdeladim, Kamel; Arab, Amar Hadj; Boulahchich, Saliha; Amrouche, Said Ould; Yassaa, Noureddine

    2018-05-01

    Almost 80 % of Algerian territory is appropriate for the exploitation of solar energy. The Algerian energetic strategy provides a substantial injection of PV electricity to the national grid. Currently, about 344 MWp of PV arrays which corresponds approximately to 2,34 km2 of module surfaces, are connected on electricity grid over the national territory. The Algerian Northern regions are characterized by strong pollution and high humidity. These phenomena affect the energetic productivity of PV generator. The objective of our study is to analyze experimental grid connected PV system power in coastal locations. Hence, experiments have been conducted on three identical PV systems to determine the electrical performances. Transformer-less inverters are the most attractive for the ground-based photovoltaic (PV) system due to their efficiencies, reduced cost and weight. Besides, the absence of the galvanic isolation generates problems of capacitive leakage current on the AC side and the degradation of the insulation resistance on the DC side of the inverter. In this work, experimental study of the behavior of single-phase inverters without transformers is presented. The main objective of this work is to study the degradation of the insulation resistance at the input of the inverter, and the capacitive leakage current at the output of the inverter. This study was achieved at the CDER on a rainy day of 15/03/2017, on the first PV plant connected to the low voltage network in Algeria. This investigation can help forecasting the PV array energetic production by taking into account natural conditions.

  20. Automatic radiation measuring system connected with GPS

    International Nuclear Information System (INIS)

    Tanigaki, Minoru

    2014-01-01

    The most serious nuclear disaster in Japan has broken out at Fukushima Daiichi Nuclear Power Plant due to Great East Japan Earthquake. Prompt and exact mapping of the contamination is of great importance for radiation protection and for the environment restoration. We have developed radiation survey systems KURAMA and KURAMA-2 for rapid and exact measurement of radiation dose distribution. The system is composed of a mobile radiation monitor and the computer in office which is for the storage and visualization of the data. They are connected with internet and are operated for continuous radiation measurement while the monitor is moving. The mobile part consists of a survey meter, an interface to transform the output of the survey meter for the computer, a global positioning system, a computer to process the data for connecting to the network, and a mobile router. Thus they are effective for rapid mapping of the surface contamination. The operation and the performance of the equipment at the site are presented. (J.P.N.)

  1. Mid-Lift-to-Drag Ratio Rigid Vehicle Control System Design and Simulation for Human Mars Entry

    Science.gov (United States)

    Johnson, Breanna J.; Cerimele, Christopher J.; Stachowiak, Susan J.; Sostaric, Ronald R.; Matz, Daniel A.; Lu, Ping

    2018-01-01

    The Mid-Lift-to-Drag Ratio Rigid Vehicle (MRV) is a proposed candidate in the NASA Evolvable Mars Campaign's (EMC) Pathfinder Entry, Descent, and Landing (EDL) architecture study. The purpose of the study is to design a mission and vehicle capable of transporting a 20mt payload to the surface of Mars. The MRV is unique in its rigid, asymmetrical lifting-body shape which enables a higher lift-to-drag ratio (L/D) than the typical robotic Mars entry capsule vehicles that carry much less mass. This paper presents the formulation and six-degree-of-freedom (6DOF) performance of the MRV's control system, which uses both aerosurfaces and a propulsive reaction control system (RCS) to affect longitudinal and lateral directional behavior.

  2. A new method using insert-based systems (IBS) to improve cell behavior study on flexible and rigid biomaterials

    OpenAIRE

    Grenade, Charlotte; Moniotte, Nicolas; Rompen, Eric; Vanheusden, Alain; Mainjot, Amélie; De Pauw-Gillet, Marie-Claire

    2016-01-01

    In vitro studies about biomaterials biological properties are essential screening tests. Yet cell cultures encounter difficulties related to cell retention on material surface or to the observation of both faces of permeable materials. The objective of the present study was to develop a reliable in vitro method to study cell behavior on rigid and flexible/permeable biomaterials elaborating two specific insert-based systems (IBS-R and IBS-F respectively). IBS-R was designed as a specific cylin...

  3. Interharmonics from Grid-Connected PV Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Sera, Dezso

    2017-01-01

    As the penetration level of grid-connected Photovoltaic (PV) systems increases, the power quality is one of the major concerns for system operators and the demands are becoming even stricter. The impact of interharmonics on the grid has been acknowledged in recent research when considering a large......-scale adoption of PV inverters. However, the origins of interharmonics remain unclear. Thus, this paper performs tests on a commercial PV inverter to explore interharmonic generation and more important investigates the mechanism of interharmonic emission. The investigation reveals that the perturbation...... of the solutions. Simulation results indicate that the constant-voltage MPPT method is the most suitable solution to the mitigation of interharmonics introduced by the MPPT operation, as it avoids the perturbation in the PV voltage during operation....

  4. Dust-Tolerant Intelligent Electrical Connection System

    Science.gov (United States)

    Lewis, Mark; Dokos, Adam; Perotti, Jose; Calle, Carlos; Mueller, Robert; Bastin, Gary; Carlson, Jeffrey; Townsend, Ivan, III; Immer, Chirstopher; Medelius, Pedro

    2012-01-01

    Faults in wiring systems are a serious concern for the aerospace and aeronautic (commercial, military, and civilian) industries. Circuit failures and vehicle accidents have occurred and have been attributed to faulty wiring created by open and/or short circuits. Often, such circuit failures occur due to vibration during vehicle launch or operation. Therefore, developing non-intrusive fault-tolerant techniques is necessary to detect circuit faults and automatically route signals through alternate recovery paths while the vehicle or lunar surface systems equipment is in operation. Electrical connector concepts combining dust mitigation strategies and cable diagnostic technologies have significant application for lunar and Martian surface systems, as well as for dusty terrestrial applications. The dust-tolerant intelligent electrical connection system has several novel concepts and unique features. It combines intelligent cable diagnostics (health monitoring) and automatic circuit routing capabilities into a dust-tolerant electrical umbilical. It retrofits a clamshell protective dust cover to an existing connector for reduced gravity operation, and features a universal connector housing with three styles of dust protection: inverted cap, rotating cap, and clamshell. It uses a self-healing membrane as a dust barrier for electrical connectors where required, while also combining lotus leaf technology for applications where a dust-resistant coating providing low surface tension is needed to mitigate Van der Waals forces, thereby disallowing dust particle adhesion to connector surfaces. It also permits using a ruggedized iris mechanism with an embedded electrodynamic dust shield as a dust barrier for electrical connectors where required.

  5. Lung involvement in systemic connective tissue diseases

    Directory of Open Access Journals (Sweden)

    Plavec Goran

    2008-01-01

    Full Text Available Background/Aim. Systemic connective tissue diseases (SCTD are chronic inflammatory autoimmune disorders of unknown cause that can involve different organs and systems. Their course and prognosis are different. All of them can, more or less, involve the respiratory system. The aim of this study was to find out the frequency of respiratory symptoms, lung function disorders, radiography and high-resolution computerized tomography (HRCT abnormalities, and their correlation with the duration of the disease and the applied treatment. Methods. In 47 non-randomized consecutive patients standard chest radiography, HRCT, and lung function tests were done. Results. Hypoxemia was present in nine of the patients with respiratory symptoms (20%. In all of them chest radiography was normal. In five of these patients lung fibrosis was established using HRCT. Half of all the patients with SCTD had symptoms of lung involvement. Lung function tests disorders of various degrees were found in 40% of the patients. The outcome and the degree of lung function disorders were neither in correlation with the duration of SCTD nor with therapy used (p > 0.05 Spearmans Ro. Conclusion. Pulmonary fibrosis occurs in about 10% of the patients with SCTD, and possibly not due to the applied treatment regimens. Hypoxemia could be a sing of existing pulmonary fibrosis in the absence of disorders on standard chest radiography.

  6. Biota: Providing often-overlooked connections among freshwater systems

    Science.gov (United States)

    Mushet, David M.; Christensen, Jay R.; Bennett, Michah; Alexander, Laurie C.

    2017-01-01

    When we think about connections in and among aquatic systems, we typically envision clear headwater streams flowing into downstream rivers, river floodwaters spilling out onto adjacent floodplains, or groundwater connecting wetlands to lakes and streams. However, there is another layer of connectivity moving materials among freshwater systems, one with connections that are not always tied to downgradient flows of surface waters and groundwater. These movements are those of organisms, key components of virtually every freshwater system on the planet. In their movements across the landscape, biota connect aquatic systems in often-overlooked ways.

  7. Review of the use of rigid and high-impact PVC pipes in natural gas distribution systems in the Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Mutter, F; Benjamin, P

    1974-08-01

    Because of a number of instances of stress corrosion cracking or crazing occurring in PVC pipes used in Dutch gas distribution systems, VEG-GASINSTITUUT began an intensive investigation of rigid PVC pipes and high-impact pipes in distribution use under various conditions and with varying service lives. The work led to an investigation of laboratory testing techniques in which the stress-cracking phenomenon found in practice could be duplicated under controllable conditions. Pipes of various materials were examined for their resistance to stress cracking, then this resistance was compared with other long- and short-term physical properties of the material.

  8. New classes of tough composite materials-Lessons from natural rigid biological systems

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, G. [Department of Materials Science and Engineering, Box 352120, University of Washington, Seattle, WA 98195-2120 (United States)]. E-mail: gmayer@u.washington.edu

    2006-09-15

    The structures and properties of a new class of composite materials, containing a predominantly high volume fraction ceramic or glass phase, combined with minor organic (adhesive) phases, have been studied. These composites have unusual combinations of mechanical properties, such as stiffness, strength, and toughness. They are based on the architecture of a rigid natural material, the nacre structure, such as those found in the shells of the abalone Haliotis rufescens, and those of other mollusk shells. The mechanisms underlying these properties have also been studied. Analogs (utilizing high-performance engineering materials), that mimic many of the mechanisms underlying those superior combinations of properties, have been built. The results of the foregoing investigations are discussed. It was found that the toughness of segmented composite beams which have high volume fractions of ceramic (89 v / o) exceeded those of continuous layered beams, as well as the monolithic ceramic (alumina) on which they are based.

  9. New classes of tough composite materials-Lessons from natural rigid biological systems

    International Nuclear Information System (INIS)

    Mayer, G.

    2006-01-01

    The structures and properties of a new class of composite materials, containing a predominantly high volume fraction ceramic or glass phase, combined with minor organic (adhesive) phases, have been studied. These composites have unusual combinations of mechanical properties, such as stiffness, strength, and toughness. They are based on the architecture of a rigid natural material, the nacre structure, such as those found in the shells of the abalone Haliotis rufescens, and those of other mollusk shells. The mechanisms underlying these properties have also been studied. Analogs (utilizing high-performance engineering materials), that mimic many of the mechanisms underlying those superior combinations of properties, have been built. The results of the foregoing investigations are discussed. It was found that the toughness of segmented composite beams which have high volume fractions of ceramic (89 v / o) exceeded those of continuous layered beams, as well as the monolithic ceramic (alumina) on which they are based

  10. A single phase photovoltaic inverter control for grid connected system

    Indian Academy of Sciences (India)

    This paper presents a control scheme for single phase grid connected photovoltaic (PV) system operating under both grid connected and isolated grid mode. The control techniques include voltage and current control of grid-tie PV inverter. During grid connected mode, grid controls the amplitude and frequency of the PV ...

  11. A new palatal distractor device for bodily movement of maxillary bones by rigid self-locking miniplates and screws system.

    Science.gov (United States)

    Cortese, Antonio; Savastano, Mauro; Cantone, Antonio; Claudio, Pier Paolo

    2013-07-01

    A new palatal distractor device for bodily movement of the maxillary bones after complete segmented Le Fort I osteotomy for 1-stage transversal distraction and tridimensional repositioning on 1 patient is presented. The new distractor has an intrinsic tridimensional rigidity also in the fixation system by self-locking miniplates and screws for better control of the 2 maxillary fragments during distraction. Le Fort I distraction and repositioning procedure in association with a bilateral sagittal split osteotomy were performed on 1 patient with complete solution of the cross-bite and class III malocclusion. Results of dental and cephalometric analysis performed before surgery (T1), after surgery and distraction time (T2), and 18 months after surgery and orthodontic appliance removal (T3) are reported. No complications were encountered using the new distractor device. Advantages of this device and technique are presented including improved rigidity of both distraction (jackscrew) and fixation (4 self-locking miniplates and screws) systems resulting in complete control of the position of the 2 maxillary fragments during distraction and surgery. In addition, this new device allows resuming palatal distraction in the event of cross-bite relapse without causing dental-related problems or the risks of screw slackening.

  12. Connected digit speech recognition system for Malayalam language

    Indian Academy of Sciences (India)

    A connected digit speech recognition is important in many applications such as automated banking system, catalogue-dialing, automatic data entry, automated banking system, etc. This paper presents an optimum speaker-independent connected digit recognizer for Malayalam language. The system employs Perceptual ...

  13. Power system services provided by inverter connected distributed energy resources

    DEFF Research Database (Denmark)

    For the last few years there has been a significant increase of DER units in Denmark, of those units more and more are connected to the power system using inverters. These inverter connected units have the potential to support the electrical power system with various power system services. One...

  14. Flocking of Second-Order Multiagent Systems With Connectivity Preservation Based on Algebraic Connectivity Estimation.

    Science.gov (United States)

    Fang, Hao; Wei, Yue; Chen, Jie; Xin, Bin

    2017-04-01

    The problem of flocking of second-order multiagent systems with connectivity preservation is investigated in this paper. First, for estimating the algebraic connectivity as well as the corresponding eigenvector, a new decentralized inverse power iteration scheme is formulated. Then, based on the estimation of the algebraic connectivity, a set of distributed gradient-based flocking control protocols is built with a new class of generalized hybrid potential fields which could guarantee collision avoidance, desired distance stabilization, and the connectivity of the underlying communication network simultaneously. What is important is that the proposed control scheme allows the existing edges to be broken without violation of connectivity constraints, and thus yields more flexibility of motions and reduces the communication cost for the multiagent system. In the end, nontrivial comparative simulations and experimental results are performed to demonstrate the effectiveness of the theoretical results and highlight the advantages of the proposed estimation scheme and control algorithm.

  15. RIGID AND NON-RIGID KINEMATIC EXCITATION FOR MULTIPLY-SUPPORTED SYSTEM: ONCE MORE ABOUT THE CONTRIBUTION OF DAMPING TO THE DYNAMIC LOADS IN SEISMIC ANALYSIS

    Directory of Open Access Journals (Sweden)

    Alexander G. Tyapin

    2018-03-01

    Full Text Available Development of linear equations of motion for seismic analysis is discussed in the paper. The paper continues the discussion: the author does not agree with colleagues putting damping matrix into the right-hand part of the equation of motion describing dynamic loads. This disagreement refers to the most popular case of “rigid” motion of multiple supports. In this paper the author follows the logic of general “non-rigid” support motion and points out a step in the equation development when the transition to “rigid” support motion (as a particular case of “non-rigid” motion is spoiled by the opponents. In the author’s opinion, the mistake is in the implementation of the Rayleigh damping model for the right-hand part of the equation. This is in the contradiction with physical logic, as damping in the Rayleigh model is not really “internal”: due to the participation of mass matrix it works on rigid displacements, which is impossible for internal damping.

  16. Hybrid system power generation'wind-photovoltaic' connected to the ...

    African Journals Online (AJOL)

    Hybrid system power generation'wind-photovoltaic' connected to the ... from Hybrid System, power delivered to or from grid and phase voltage of the inverter leg. ... Renewable Energy, Electrical Network 220 kV, Hybrid System, Solar, MPPT.

  17. Too close and too rigid: applying the Circumplex Model of Family Systems to first-generation family firms.

    Science.gov (United States)

    Michael-Tsabari, Nava; Lavee, Yoav

    2012-06-01

    Despite growing research interest in family businesses, little is known about the characteristics of the families engaging in them. The present paper uses Olson's (Journal of Psychotherapy & the Family, 1988, 4(12), 7-49; Journal of Family Therapy, 2000, 22, 144-167) Circumplex Model of Marital and Family Systems to look at first-generation family firms. We describe existing typologies of family businesses and discuss similarities between the characteristics of first-generation family firms and the rigidly enmeshed family type described in the Circumplex Model. The Steinberg family business (Gibbon & Hadekel (1990) Steinberg: The breakup of a family empire. ON, Canada: MacMillan) serves to illustrate the difficulties of rigidly enmeshed first-generation family firms. Implications for understanding troubled family businesses are discussed together with guidelines for the assessment of a family business in crisis and for intervention: enhancing open communication; allowing for more flexible leadership style, roles, and rules; and maintaining a balance between togetherness and separateness. © 2012 American Association for Marriage and Family Therapy.

  18. Low-voltage grid-connection of photovoltaic power systems

    Energy Technology Data Exchange (ETDEWEB)

    Collinson, A.; Thornycroft, J.

    1999-07-01

    This report summarises the results of a project aimed at developing technical guidelines concerning grid connected photovoltaic (PV) inverter generators which are to be published in draft form as the {sup U}K Technical Guidelines for Inverter Connected Single Phase Photovoltaic (PV) Generators up to 5kVA{sup .} The background to the use of PV in the UK is traced, and the technical criteria for electrical integration of PV systems, and UK guidelines for grid connected PV systems are examined. The findings of the working group of the International Energy Agency (IEA) Implementing Agreement on Photovoltaic Power Systems are also presented in this report. Appendices discuss the UK technical guidelines, the IEA Task V activities,, utility aspects of grid-connected PV systems, and demonstration tests on grid-connected PV systems, and lists Task V reports.

  19. Rigidity of monodromies for Appell's hypergeometric functions

    Directory of Open Access Journals (Sweden)

    Yoshishige Haraoka

    2015-01-01

    Full Text Available For monodromy representations of holonomic systems, the rigidity can be defined. We examine the rigidity of the monodromy representations for Appell's hypergeometric functions, and get the representations explicitly. The results show how the topology of the singular locus and the spectral types of the local monodromies work for the study of the rigidity.

  20. Review international standards for grid connected photovoltaic systems in Malaysia

    International Nuclear Information System (INIS)

    Mekhilef, S.; Rahim, N.A.

    2006-01-01

    Grid connected PV is being applied on variety application including large centralised stations, commercial building and individual houses. There is a need for specific standard to address distinctive new issue created by grid connected PV power system. Internationally many countries are attempting to develop standards for building integration, Dc side issues and grid connection issues. This paper surveys the current development state of the major countries standards in this area, comparing and contrasting, standards and guideline under development, also addressing the need of standards for grid connected in Malaysia

  1. On flexible and rigid nouns

    DEFF Research Database (Denmark)

    Rijkhoff, Jan

    2010-01-01

    classes. Finally this article wants to claim that the distinction between rigid and flexible noun categories (a) adds a new dimension to current classifications of parts of speech systems, (b) correlates with certain grammatical phenomena (e.g. so-called number discord), and (c) helps to explain the parts......This article argues that in addition to the major flexible lexical categories in Hengeveld’s classification of parts of speech systems (Contentive, Non-Verb, Modifier), there are also flexible word classes within the rigid lexical category Noun (Set Noun, Sort Noun, General Noun). Members...... by the flexible item in the external world. I will then argue that flexible word classes constitute a proper category (i.e. they are not the result of a merger of some rigid word classes) in that members of flexible word categories display the same properties regarding category membership as members of rigid word...

  2. H infinity controller design to a rigid-flexible satellite with two vibration modes

    International Nuclear Information System (INIS)

    De Souza, A G; De Souza, L C G

    2015-01-01

    The satellite attitude control system (ACS) design becomes more complex when the satellite structure has components like, flexible solar panels, antennas and mechanical manipulators. These flexible structures can interact with the satellite rigid parts during translational and/or rotational manoeuvre damaging the ACS pointing accuracy. Although, a well-designed controller can suppress such disturbances quickly, the controller error pointing may be limited by the minimum time necessary to suppress such disturbances thus affecting the satellite attitude acquisition. This paper deals with the rigid-flexible satellite ACS design using the H infinity method. The rigid-flexible satellite is represented by a beam connected to a central rigid hub at one end and free at the other one. The equations of motions are obtained considering small flexible deformations and the Euler-Bernoulli hypothesis. The results of the simulations have shown that the H-infinity controller was able to control the rigid motion and suppress the vibrations. (paper)

  3. Connecting the Astrophysics Data System and Planetary Data System

    Science.gov (United States)

    Eichhorn, G.; Kurtz, M. J.; Accomazzi, A.; Grant, C. S.; Murray, S. S.; Hughes, J. S.; Mortellaro, J.; McMahon, S. K.

    1997-07-01

    The Astrophysics Data System (ADS) provides access to astronomical literature through a sophisticated search engine. Over 10,000 users retrieve almost 5 million references and read more than 25,000 full text articles per month. ADS cooperates closely with all the main astronomical journals and data centers to create and maintain a state-of-the-art digital library. The Planetary Data System (PDS) publishes high quality peer reviewed planetary science data products, defines planetary archiving standards to make products usable, and provides science expertise to users in data product preparation and use. Data products are available to users on CD media, with more than 600 CD-ROM titles in the inventory from past missions as well as the recent releases from active planetary missions and observations. The ADS and PDS serve overlapping communities and offer complementary functions. The ADS and PDS are both part of the NASA Space Science Data System, sponsored by the Office of Space Science, which curates science data products for researchers and the general public. We are in the process of connecting these two data systems. As a first step we have included entries for PDS data sets in the ADS abstract service. This allows ADS users to find PDS data sets by searching for their descriptions through the ADS search system. The information returned from the ADS links directly to the data set's entry in the PDS data set catalog. After linking to this catalog, the user will have access to more comprehensive data set information, related ancillary information, and on-line data products. The PDS on the other hand will use the ADS to provide access to bibliographic information. This includes links from PDS data set catalog bibliographic citations to ADS abstracts and on-line articles. The cross-linking between these data systems allows each system to concentrate on its main objectives and utilize the other system to provide more and improved services to the users of both systems.

  4. The microbiome-systemic diseases connection

    NARCIS (Netherlands)

    van der Meulen, T. A.; Harmsen, H. J. M.; Bootsma, H.; Spijkervet, F. K. L.; Kroese, F. G. M.; Vissink, A.

    2016-01-01

    The human microbiome consists of all microorganisms occupying the skin, mucous membranes and intestinal tract of the human body. The contact of the mucosal immune system with the human microbiome is a balanced interplay between defence mechanisms of the immune system and symbiotic or pathogenic

  5. Overview of Single-Phase Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede

    2017-01-01

    A continuous booming installation of solar photovoltaic (PV) systems has been witnessed worldwide. It is mainly driven by the imperative demand of “clean” power generation from renewables. Grid-connected PV systems will thus become an even more active player in the future mixed power systems, which...... systems. This chapter thus gives an overview of the advancement of power electronics converters in single-phase grid-connected PV systems, being commonly used in residential applications. Demands to single-phase grid-connected PV systems and the general control strategies are also addressed...... are linked together by a vast of power electronics converters and the power grid. In order to achieve a reliable and efficient power generation from PV systems, more stringent demands have been imposed on the entire PV system. It, in return, advances the development of the power converter technology in PV...

  6. Grid-connected distributed solar power systems

    Science.gov (United States)

    Moyle, R.; Chernoff, H.; Schweizer, T.

    This paper discusses some important, though often ignored, technical and economic issues of distributed solar power systems: protection of the utility system and nonsolar customers requires suitable interfaced equipment. Purchase criteria must mirror reality; most analyses use life-cycle costing with low discount rates - most buyers use short payback periods. Distributing, installing, and marketing small, distributed solar systems is more costly than most analyses estimate. Results show that certain local conditions and uncommon purchase considerations can combine to make small, distributed solar power attractive, but lower interconnect costs (per kW), lower marketing and product distribution costs, and more favorable purchase criteria make large, centralized solar energy more attractive. Specifically, the value of dispersed solar systems to investors and utilities can be higher than $2000/kw. However, typical residential owners place a value of well under $1000 on the installed system.

  7. Grid-connected photovoltaic system design for local government ...

    African Journals Online (AJOL)

    Grid-connected photovoltaic system design for local government offices in Nigeria. ... Nigerian Journal of Technology. Journal Home ... It is neat, silent and elegant process of generating electric power in environmentally friendly manner. In this ...

  8. Industry consultation on grid connection of small PV systems

    Energy Technology Data Exchange (ETDEWEB)

    Knight, J.; Thorneycroft, J.; Cotterell, M.; Gambro, S.

    2000-07-01

    This report presents the results of consultation within the PV industry and the electricity supply industry concerning guidelines for the connection of small PV systems to the electricity network. (author)

  9. Considering the Practical Rationality of Experimental Operation in Developing Countries: Reality and Challenges under a Rigid Community Forestry System in Cambodia

    Directory of Open Access Journals (Sweden)

    Takayuki Kurashima

    2015-09-01

    Full Text Available Influential stakeholders have highlighted many constraints inherent in conventional scientific forest management plans for community forestry (CF and presented simpler alternatives. Nevertheless, some developing countries continue to use rigid, complex and high-cost plans and regulations. This article considers two issues: (1 why heavily-regulated or rigid CF systems were originally introduced and why they continue to be used in developing countries despite critiques and counterproposals; and (2 under what circumstances will such CF systems face an impasse, and what can be done to resolve the situation. Using Cambodia as a case study, we examine the development of a rigid CF system, review negative factors influencing the upland forested area, clarify the unfavorable situations arising from these factors and discuss likely problems associated with the CF management system. International organizations played a key role in the introduction and maintenance of rigid, complex and high-cost CF systems in Cambodia. Conflicts and crises arise when the administration prosecutes local farmers for illegal cultivation or deprives communities of CF management rights because of the expansion of commercial crop cultivation and the lack of adequate community management in response to unprecedented changes. A likely practical solution to the probable impasse is the development and funding of a functional network of CF management committees, rather than the adoption of an entirely new, alternative system.

  10. A new method using insert-based systems (IBS) to improve cell behavior study on flexible and rigid biomaterials.

    Science.gov (United States)

    Grenade, Charlotte; Moniotte, Nicolas; Rompen, Eric; Vanheusden, Alain; Mainjot, Amélie; De Pauw-Gillet, Marie-Claire

    2016-12-01

    In vitro studies about biomaterials biological properties are essential screening tests. Yet cell cultures encounter difficulties related to cell retention on material surface or to the observation of both faces of permeable materials. The objective of the present study was to develop a reliable in vitro method to study cell behavior on rigid and flexible/permeable biomaterials elaborating two specific insert-based systems (IBS-R and IBS-F respectively). IBS-R was designed as a specific cylindrical polytetrafluoroethylene (PTFE) system to evaluate attachment, proliferation and morphology of human gingival fibroblasts (HGFs) on grade V titanium and lithium disilicate glass-ceramic discs characteristics of dental prostheses. The number of cells, their covering on discs and their morphology were determined from MTS assays and microscopic fluorescent images after 24, 48 and 72 h. IBS-F was developed as a two components system to study HGFs behavior on guided bone regeneration polyester membranes. The viability and the membrane barrier effect were evaluated by metabolic MTS assays and by scanning electron microscopy. IBS-R and IBS-F were shown to promote (1) easy and rapid handling; (2) cell retention on biomaterial surface; (3) accurate evaluation of the cellular proliferation, spreading and viability; (4) use of non-toxic material. Moreover IBS-F allowed the study of the cell migration through degradable membranes, with an access to both faces of the biomaterial and to the bottom of culture wells for medium changing.

  11. Low noise wing slat system with rigid cove-filled slat

    Science.gov (United States)

    Shmilovich, Arvin (Inventor); Yadlin, Yoram (Inventor)

    2013-01-01

    Concepts and technologies described herein provide for a low noise aircraft wing slat system. According to one aspect of the disclosure provided herein, a cove-filled wing slat is used in conjunction with a moveable panel rotatably attached to the wing slat to provide a high lift system. The moveable panel rotates upward against the rear surface of the slat during deployment of the slat, and rotates downward to bridge a gap width between the stowed slat and the lower wing surface, completing the continuous outer mold line shape of the wing, when the cove-filled slat is retracted to the stowed position.

  12. Fluid-structure interaction in non-rigid pipeline systems - large scale validation experiments

    International Nuclear Information System (INIS)

    Heinsbroek, A.G.T.J.; Kruisbrink, A.C.H.

    1993-01-01

    The fluid-structure interaction computer code FLUSTRIN, developed by DELFT HYDRAULICS, enables the user to determine dynamic fluid pressures, structural stresses and displacements in a liquid-filled pipeline system under transient conditions. As such, the code is a useful tool to process and mechanical engineers in the safe design and operation of pipeline systems in nuclear power plants. To validate FLUSTRIN, experiments have been performed in a large scale 3D test facility. The test facility consists of a flexible pipeline system which is suspended by wires, bearings and anchors. Pressure surges, which excite the system, are generated by a fast acting shut-off valve. Dynamic pressures, structural displacements and strains (in total 70 signals) have been measured under well determined initial and boundary conditions. The experiments have been simulated with FLUSTRIN, which solves the acoustic equations using the method of characteristics (fluid) and the finite element method (structure). The agreement between experiments and simulations is shown to be good: frequencies, amplitudes and wave phenomena are well predicted by the numerical simulations. It is demonstrated that an uncoupled water hammer computation would render unreliable and useless results. (author)

  13. Here we go again: A dynamic systems perspective on emotional rigidity across parent-adolescent conflicts

    NARCIS (Netherlands)

    Lichtwarck-Aschoff, A.; Kunnen, E.S.; Geert, P.L.C. van

    2009-01-01

    The authors used a dynamic systems theoretical approach to examine intraindividual variability in emotional responses during the transitional period of adolescence. Longitudinal diary data were collected regarding conflicts between 17 teenage girls and their mothers over a period of a year. The

  14. Approximate analysis of rigid plate loading on elastic multi-layered systems

    CSIR Research Space (South Africa)

    Maina, JW

    2008-07-01

    Full Text Available , this distribution was approximated using uniformly distributed multiple loads and analysis performed using Games. Results have shown good agreement with the theory for the case of a semi-infinite medium. Furthermore, extension of this method to multilayered system...

  15. Evaluation of PEGIT duct connection system

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain S.; Brenner, Douglas E.; Sherman, Max H.; Dickerhoff, Darryl J.

    2003-08-01

    Most air duct system components are assembled in the field and are mechanically fastened by sheet metal screws (for sheet metal-to-sheet metal) or by drawbands (for flex duct-to-sheet metal). Air sealing is separate from this mechanical fastening and is usually achieved using tape or mastic products after mechanical fastening. Field observations have shown that mechanical fastening rarely meets code or manufacturers requirements and that sealing procedures are similarly inconsistent. To address these problems, Proctor Engineering Group (PEG) is developing a system of joining ducts (called PEGIT) that combines the mechanical fastening and sealing into a single self-contained procedure. The PEGIT system uses a shaped flexible seal between specially designed sheet metal duct fittings to both seal and fasten duct sections together. Figure 1 shows the inner duct fitting complete with rubber seal. This seal provides the air seal for the completed fitting and is shaped to allow the inner and outer fittings to slide together, and then to lock the fittings in place. The illustration in Figure 2 shows the approximate cross section of the rubber seal that shows how the seal has a lip that is angled backwards. This angled lip allows the joint to be pushed together by folding flat but then its long axis makes it stiff in the pulling apart direction. This study was undertaken to assist PEG in some of the design aspects of this system and to test the performance of the PEGIT system. This study was carried out in three phases. The initial phase evaluated the performance of a preliminary seal design for the PEGIT system. After the first phase, the seal was redesigned and this new seal was evaluated in the second phase of testing. The third phase performed more detailed testing of the second seal design to optimize the production tolerances of the sheet metal fittings. This report summarizes our findings from the first two phases and provides details about the third phase of testing.

  16. Overview of Single-Phase Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede

    2015-01-01

    A still booming installation of solar photovoltaic (PV) systems has been witnessed worldwide. It is mainly driven by the demand of “clean” power generation. Grid-connected PV systems will become an even active player in the future mixed power systems, which are linked by a vast of power electronics...

  17. Understanding ecohydrological connectivity in savannas: A system dynamics modeling approach

    Science.gov (United States)

    Ecohydrological connectivity is a system-level property that results from the linkages in the networks of water transport through ecosystems, by which feedback effects and other emergent system behaviors may be generated. We created a systems dynamic model that represents primary ecohydrological net...

  18. Snaps to Connect Coaxial and Microstrip Lines in Wearable Systems

    Directory of Open Access Journals (Sweden)

    Tiiti Kellomäki

    2012-01-01

    Full Text Available Commercial snaps (clothing fasteners can be used to connect a coaxial cable to a microstrip line. This is useful in the context of wearable antennas, especially in consumer applications and disposable connections. The measured S-parameters of the transition are presented, and an equivalent circuit and approximate equations are derived for system design purposes. The proposed connection is usable up to 1.5 GHz (10 dB return loss condition, and the frequency range can be extended to 2 GHz if a thinner, more flexible coaxial cable is used.

  19. A heterogeneous system based on GPU and multi-core CPU for real-time fluid and rigid body simulation

    Science.gov (United States)

    da Silva Junior, José Ricardo; Gonzalez Clua, Esteban W.; Montenegro, Anselmo; Lage, Marcos; Dreux, Marcelo de Andrade; Joselli, Mark; Pagliosa, Paulo A.; Kuryla, Christine Lucille

    2012-03-01

    Computational fluid dynamics in simulation has become an important field not only for physics and engineering areas but also for simulation, computer graphics, virtual reality and even video game development. Many efficient models have been developed over the years, but when many contact interactions must be processed, most models present difficulties or cannot achieve real-time results when executed. The advent of parallel computing has enabled the development of many strategies for accelerating the simulations. Our work proposes a new system which uses some successful algorithms already proposed, as well as a data structure organisation based on a heterogeneous architecture using CPUs and GPUs, in order to process the simulation of the interaction of fluids and rigid bodies. This successfully results in a two-way interaction between them and their surrounding objects. As far as we know, this is the first work that presents a computational collaborative environment which makes use of two different paradigms of hardware architecture for this specific kind of problem. Since our method achieves real-time results, it is suitable for virtual reality, simulation and video game fluid simulation problems.

  20. Structural and Functional Connectivity from Unmanned-Aerial System Data

    Science.gov (United States)

    Masselink, Rens; Heckmann, Tobias; Casalí, Javier; Giménez, Rafael; Cerdá, Artemi; Keesstra, Saskia

    2017-04-01

    Over the past decade there has been an increase in both connectivity research and research involving Unmanned-Aerial systems (UASs). In some studies, UASs were successfully used for the assessment of connectivity, but not yet to their full potential. We present several ways to use data obtained from UASs to measure variables related to connectivity, and use these to assess both structural and functional connectivity. These assessments of connectivity can aid us in obtaining a better understanding of the dynamics of e.g. sediment and nutrient transport. We identify three sources of data obtained from a consumer camera mounted on a fixed-wing UAS, which can be used separately or combined: Visual and near-infrared imagery, point clouds, and digital elevation models (DEMs). Imagery (or: orthophotos) can be used for (automatic) mapping of connectivity features like rills, gullies and soil and water conservation measures using supervised or unsupervised classification methods with e.g. Object-Based Image Analysis. Furthermore, patterns of soil moisture in the top layers can be extracted from visual and near-infrared imagery. Point clouds can be analysed for vegetation height and density, and soil surface roughness. Lastly, DEMs can be used in combination with imagery for a number of tasks, including raster-based (e.g. DEM derivatives) and object-based (e.g., feature detection) analysis: Flow routing algorithms can be used to analyse potential pathways of surface runoff and sediment transport. This allows for the assessment of structural connectivity through indices that are based, for example, on morphometric and other properties of surfaces, contributing areas, and pathways. Third, erosion and deposition can be measured by calculating elevation changes from repeat surveys. From these "intermediate" variables like roughness, vegetation density and soil moisture, structural connectivity and functional connectivity can be assessed by combining them into a dynamic index of

  1. Rigidity-tuning conductive elastomer

    Science.gov (United States)

    Shan, Wanliang; Diller, Stuart; Tutcuoglu, Abbas; Majidi, Carmel

    2015-06-01

    We introduce a conductive propylene-based elastomer (cPBE) that rapidly and reversibly changes its mechanical rigidity when powered with electrical current. The elastomer is rigid in its natural state, with an elastic (Young’s) modulus of 175.5 MPa, and softens when electrically activated. By embedding the cPBE in an electrically insulating sheet of polydimethylsiloxane (PDMS), we create a cPBE-PDMS composite that can reversibly change its tensile modulus between 37 and 1.5 MPa. The rigidity change takes ˜6 s and is initiated when a 100 V voltage drop is applied across the two ends of the cPBE film. This magnitude of change in elastic rigidity is similar to that observed in natural skeletal muscle and catch connective tissue. We characterize the tunable load-bearing capability of the cPBE-PDMS composite with a motorized tensile test and deadweight experiment. Lastly, we demonstrate the ability to control the routing of internal forces by embedding several cPBE-PDMS ‘active tendons’ into a soft robotic pneumatic bending actuator. Selectively activating the artificial tendons controls the neutral axis and direction of bending during inflation.

  2. Rigidity-tuning conductive elastomer

    International Nuclear Information System (INIS)

    Shan, Wanliang; Diller, Stuart; Tutcuoglu, Abbas; Majidi, Carmel

    2015-01-01

    We introduce a conductive propylene-based elastomer (cPBE) that rapidly and reversibly changes its mechanical rigidity when powered with electrical current. The elastomer is rigid in its natural state, with an elastic (Young’s) modulus of 175.5 MPa, and softens when electrically activated. By embedding the cPBE in an electrically insulating sheet of polydimethylsiloxane (PDMS), we create a cPBE–PDMS composite that can reversibly change its tensile modulus between 37 and 1.5 MPa. The rigidity change takes ∼6 s and is initiated when a 100 V voltage drop is applied across the two ends of the cPBE film. This magnitude of change in elastic rigidity is similar to that observed in natural skeletal muscle and catch connective tissue. We characterize the tunable load-bearing capability of the cPBE–PDMS composite with a motorized tensile test and deadweight experiment. Lastly, we demonstrate the ability to control the routing of internal forces by embedding several cPBE–PDMS ‘active tendons’ into a soft robotic pneumatic bending actuator. Selectively activating the artificial tendons controls the neutral axis and direction of bending during inflation. (paper)

  3. Effects of nonlinearity in the materials used for the semi-rigid pedicle screw systems on biomechanical behaviors of the lumbar spine after surgery

    International Nuclear Information System (INIS)

    Kim, Hyun; Lee, Sung-Jae; Lim, Do-Hyung; Oh, Hyun-Ju; Lee, Kwon-Yong

    2011-01-01

    Recently, various types of semi-rigid pedicle screw fixation systems have been developed for the surgical treatment of the lumbar spine. They were introduced to address the adverse issues commonly found in traditional rigid spinal fusion--abnormally large motion at the adjacent level and subsequent degeneration. The semi-rigid system uses more compliant materials (nitinol or polymers) and/or changes in rod design (coiled or twisted rods) as compared to the conventional rigid straight rods made of Ti alloys (E = 114 GPa, υ = 0.32). However, biomechanical studies on the semi-rigid pedicle screw systems were usually limited to linear modeling of the implant and anatomic elements, which may not be capable of reflecting realistic post-operative motions of the spine. In this study, we evaluated the effects of nonlinearity in materials used for semi-rigid pedicle screw fixation systems to evaluate the changes in biomechanical behaviors using finite element analysis. Changes in range of motion (ROM) and center of rotation (COR) were assessed at the operated and adjacent levels. Actual load-displacement results of the semi-rigid rod from mechanical test were carried out to reflect the nonlinearity of the implant. In addition, nonlinear material properties of various spinal ligaments studies were used for the finite element modeling. The post-operative models were constructed by modifying the previously validated intact model of the L1-S1 spine. Eight different post-operative models were made to address the effects of nonlinearity-with a traditional stiffness modulus rod (with linear ligaments, case 1; with nonlinear ligaments, case 5), with a rigid rod (with linear ligaments, case 2; with nonlinear ligaments, case 6), with a soft rod (with linear ligaments, case 3; with nonlinear ligaments, case 7), and with a nonlinear rod (with linear ligaments, case 4; with nonlinear ligaments, case 8). To simulate the load on the lumbar spine in a neutral posture, follower load (400 N

  4. Grid-connected inverter for wind power generation system

    Institute of Scientific and Technical Information of China (English)

    YANG Yong; RUAN Yi; SHEN Huan-qing; TANG Yan-yan; YANG Ying

    2009-01-01

    In wind power generation system the grid-connected inverter is an important section for energy conversion and transmission, of which the performance has a direct influence on the entire wind power generation system. The mathematical model of the grid-connected inverter is deduced firstly. Then, the space vector pulse width modulation (SVPWM) is analyzed. The power factor can be controlled close to unity, leading or lagging, which is realized based on PI-type current controller and grid voltage vector-oriented control. The control strategy is verified by the simulation and experimental results with a good sinusoidal current, a small harmonic component and a fast dynamic response.

  5. Electrical system studies for the grid connection of wind farms

    International Nuclear Information System (INIS)

    Arp, K.; Hanson, J.; Hopp, S.; Zimmermann, W.

    2007-01-01

    Wind power is gaining momentum in the world's energy balance. Several issues have to be addressed whenever power-generating devices are connected to the grid. The paper describes studies needed to evaluate the influence of wind farms on the connected transmission system and how faults in the system impact on induction generators in a wind farm. Some generalized results of studies for an offshore wind farm in the North Sea and a Bulgarian wind farm show how studies can influence the layout of the internal network and the electrical equipment. (authors)

  6. Medial vestibular connections with the hypocretin (orexin) system

    Science.gov (United States)

    Horowitz, Seth S.; Blanchard, Jane; Morin, Lawrence P.

    2005-01-01

    The mammalian medial vestibular nucleus (MVe) receives input from all vestibular endorgans and provides extensive projections to the central nervous system. Recent studies have demonstrated projections from the MVe to the circadian rhythm system. In addition, there are known projections from the MVe to regions considered to be involved in sleep and arousal. In this study, afferent and efferent subcortical connectivity of the medial vestibular nucleus of the golden hamster (Mesocricetus auratus) was evaluated using cholera toxin subunit-B (retrograde), Phaseolus vulgaris leucoagglutinin (anterograde), and pseudorabies virus (transneuronal retrograde) tract-tracing techniques. The results demonstrate MVe connections with regions mediating visuomotor and postural control, as previously observed in other mammals. The data also identify extensive projections from the MVe to regions mediating arousal and sleep-related functions, most of which receive immunohistochemically identified projections from the lateral hypothalamic hypocretin (orexin) neurons. These include the locus coeruleus, dorsal and pedunculopontine tegmental nuclei, dorsal raphe, and lateral preoptic area. The MVe itself receives a projection from hypocretin cells. CTB tracing demonstrated reciprocal connections between the MVe and most brain areas receiving MVe efferents. Virus tracing confirmed and extended the MVe afferent connections identified with CTB and additionally demonstrated transneuronal connectivity with the suprachiasmatic nucleus and the medial habenular nucleus. These anatomical data indicate that the vestibular system has access to a broad array of neural functions not typically associated with visuomotor, balance, or equilibrium, and that the MVe is likely to receive information from many of the same regions to which it projects.

  7. Traffic Congestion Detection System through Connected Vehicles and Big Data

    OpenAIRE

    Néstor Cárdenas-Benítez; Raúl Aquino-Santos; Pedro Magaña-Espinoza; José Aguilar-Velazco; Arthur Edwards-Block; Aldo Medina Cass

    2016-01-01

    This article discusses the simulation and evaluation of a traffic congestion detection system which combines inter-vehicular communications, fixed roadside infrastructure and infrastructure-to-infrastructure connectivity and big data. The system discussed in this article permits drivers to identify traffic congestion and change their routes accordingly, thus reducing the total emissions of CO2 and decreasing travel time. This system monitors, processes and stores large amounts of data, which ...

  8. Spreading Sequence System for Full Connectivity Relay Network

    Science.gov (United States)

    Kwon, Hyuck M. (Inventor); Yang, Jie (Inventor); Pham, Khanh D. (Inventor)

    2018-01-01

    Fully connected uplink and downlink fully connected relay network systems using pseudo-noise spreading and despreading sequences subjected to maximizing the signal-to-interference-plus-noise ratio. The relay network systems comprise one or more transmitting units, relays, and receiving units connected via a communication network. The transmitting units, relays, and receiving units each may include a computer for performing the methods and steps described herein and transceivers for transmitting and/or receiving signals. The computer encodes and/or decodes communication signals via optimum adaptive PN sequences found by employing Cholesky decompositions and singular value decompositions (SVD). The PN sequences employ channel state information (CSI) to more effectively and more securely computing the optimal sequences.

  9. Signature of Thermal Rigidity Percolation

    International Nuclear Information System (INIS)

    Huerta, Adrián

    2013-01-01

    To explore the role that temperature and percolation of rigidity play in determining the macroscopic properties, we propose a model that adds translational degrees of freedom to the spins of the well known Ising hamiltonian. In particular, the Ising model illustrate the longstanding idea that the growth of correlations on approach to a critical point could be describable in terms of the percolation of some sort of p hysical cluster . For certain parameters of this model we observe two well defined peaks of C V , that suggest the existence of two kinds of p hysical percolation , namely connectivity and rigidity percolation. Thermal fluctuations give rise to two different kinds of elementary excitations, i.e. droplets and configuron, as suggested by Angell in the framework of a bond lattice model approach. The later is reflected in the fluctuations of redundant constraints that gives stability to the structure and correlate with the order parameter

  10. SECONDARY PULMONARY ARTERIAL HYPERTENSION IN SYSTEMIC DISEASES OF CONNECTIVE TISSUE

    Directory of Open Access Journals (Sweden)

    N. A. Shostak

    2016-01-01

    Full Text Available Modern definition of pulmonary arterial hypertension (PAH as well as data on prevalence and incidence of secondary PAH in systemic disease of connective tissue is presented,  including data of USA, France and Scotland registers. The main chains of pathogenesis, classification approaches, clinical features and diagnostics are described. 

  11. SECONDARY PULMONARY ARTERIAL HYPERTENSION IN SYSTEMIC DISEASES OF CONNECTIVE TISSUE

    Directory of Open Access Journals (Sweden)

    N. A. Shostak

    2009-01-01

    Full Text Available Modern definition of pulmonary arterial hypertension (PAH as well as data on prevalence and incidence of secondary PAH in systemic disease of connective tissue is presented,  including data of USA, France and Scotland registers. The main chains of pathogenesis, classification approaches, clinical features and diagnostics are described. 

  12. Quantum-Classical Connection for Hydrogen Atom-Like Systems

    Science.gov (United States)

    Syam, Debapriyo; Roy, Arup

    2011-01-01

    The Bohr-Sommerfeld quantum theory specifies the rules of quantization for circular and elliptical orbits for a one-electron hydrogen atom-like system. This article illustrates how a formula connecting the principal quantum number "n" and the length of the major axis of an elliptical orbit may be arrived at starting from the quantum…

  13. Repetitive controller for improving grid-connected photovoltaic systems

    NARCIS (Netherlands)

    Almeida, de P.M.; Duarte, J.L.; Ribeiro, P.F.; Barbosa, P.G.

    2014-01-01

    This study presents the modelling and design steps of a discrete time recursive repetitive controller (RC) to be used in a grid-connected photovoltaic (PV) system. It is shown that the linear synchronous reference frame proportional-integral controller, originally designed to control the converter's

  14. Connected Lighting System Interoperability Study Part 1: Application Programming Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Gaidon, Clement [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Poplawski, Michael [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-10-31

    First in a series of studies that focuses on interoperability as realized by the use of Application Programming Interfaces (APIs), explores the diversity of such interfaces in several connected lighting systems; characterizes the extent of interoperability that they provide; and illustrates challenges, limitations, and tradeoffs that were encountered during this exploration.

  15. Bolted Flanged Connection for Critical Plant/Piping Systems

    International Nuclear Information System (INIS)

    Efremov, Anatoly

    2006-01-01

    A novel type of Bolted Flanged Connection with bolts and gasket manufactured on a basis of advanced Shape Memory Alloys is examined. Presented approach combined with inverse flexion flange design of plant/piping joint reveals a significant increase of internal pressure under conditions of a variety of operating temperatures relating to critical plant/piping systems. (author)

  16. A topological classification of the Chaplygin systems in the dynamics of a rigid body in a fluid

    International Nuclear Information System (INIS)

    Nikolaenko, S S

    2014-01-01

    The paper is concerned with the topological analysis of the Chaplygin integrable case in the dynamics of a rigid body in a fluid. A full list of the topological types of Chaplygin systems in their dependence on the energy level is compiled on the basis of the Fomenko-Zieschang theory. An effective description of the topology of the Liouville foliation in terms of natural coordinate variables is also presented, which opens a direct way to calculating topological invariants. It turns out that on all nonsingular energy levels Chaplygin systems are Liouville equivalent to the well-known Euler case in the dynamics of a rigid body with fixed point. Bibliography: 23 titles

  17. Overview of Single-Phase Grid-Connected Photovoltaic Systems

    OpenAIRE

    Yang, Yongheng; Blaabjerg, Frede

    2015-01-01

    A still booming installation of solar photovoltaic (PV) systems has been witnessed worldwide. It is mainly driven by the demand of “clean” power generation. Grid-connected PV systems will become an even active player in the future mixed power systems, which are linked by a vast of power electronics converters. In order to achieve a reliable and efficient power generation from PV systems, stringent demands have been imposed on the entire PV system. It in return advances the development of powe...

  18. THE NEED OF CONNECTING THE TECHNOLOGY, POLITICAL AND CULTURAL SYSTEM

    Directory of Open Access Journals (Sweden)

    Marija Merdzhanovska

    2016-12-01

    Full Text Available The paper explores the need of connecting the technology, political and cultural system in the right way to achieve the companies’ goals in terms of globalization and changes. The leaders have the main role in realizing the company’s strategy. They must be strategy focused and they are responsible for connecting the employees, processes and technologies. In the beginning of the paper, the characteristics of strategy focused leadership are analyzed. The available tools of strategy focused leadership through the model are presented. The matrix of strategy management can be used like a manual which helps the management in connecting systems with managerial instruments: mission and strategy, organization structure and management of human resources. The goal of the paper is to show that with professional approach, the strategy focused leaders play the main role in connecting and changing the existing systems in companies. This is the way of reaching the best performance of companies and surviving at the global world market.

  19. Performance Parameters for Grid-Connected PV Systems

    Energy Technology Data Exchange (ETDEWEB)

    Marion, B.; Adelstein, J.; Boyle, K.; Hayden, H.; Hammond, B.; Fletcher, T.; Canada, B.; Narang, D.; Shugar, D.; Wenger, H.; Kimber, A.; Mitchell, L.; Rich, G.; Townsend, T.

    2005-02-01

    The use of appropriate performance parameters facilitates the comparison of grid-connected photovoltaic (PV) systems that may differ with respect to design, technology, or geographic location. Four performance parameters that define the overall system performance with respect to the energy production, solar resource, and overall effect of system losses are the following: final PV system yield, reference yield, performance ratio, and PVUSA rating. These performance parameters are discussed for their suitability in providing desired information for PV system design and performance evaluation and are demonstrated for a variety of technologies, designs, and geographic locations. Also discussed are methodologies for determining system a.c. power ratings in the design phase using multipliers developed from measured performance parameters.The use of appropriate performance parameters facilitates the comparison of grid-connected photovoltaic (PV) systems that may differ with respect to design, technology, or geographic location. Four performance parameters that define the overall system performance with respect to the energy production, solar resource, and overall effect of system losses are the following: final PV system yield, reference yield, performance ratio, and PVUSA rating. These performance parameters are discussed for their suitability in providing desired information for PV system design and performance evaluation and are demonstrated for a variety of technologies, designs, and geographic locations. Also discussed are methodologies for determining system a.c. power ratings in the design phase using multipliers developed from measured performance parameters.

  20. Metric for Calculation of System Complexity based on its Connections

    Directory of Open Access Journals (Sweden)

    João Ricardo Braga de Paiva

    2017-02-01

    Full Text Available This paper proposes a methodology based on system connections to calculate its complexity. Two study cases are proposed: the dining Chinese philosophers’ problem and the distribution center. Both studies are modeled using the theory of Discrete Event Systems and simulations in different contexts were performed in order to measure their complexities. The obtained results present i the static complexity as a limiting factor for the dynamic complexity, ii the lowest cost in terms of complexity for each unit of measure of the system performance and iii the output sensitivity to the input parameters. The associated complexity and performance measures aggregate knowledge about the system.

  1. A Desktop Screen Sharing System based on Various Connection Methods

    Science.gov (United States)

    Negishi, Yuya; Kawaguchi, Nobuo

    Recently it became very common to use information devices such as PCs during presentations and discussions. In these situations, a need arises for techniques that allow a smooth switch of presenters without changing cables, or an easy screen sharing in case of remote videoconferences. In this paper, we propose a desktop screen sharing system that can be used for such purposes and situations. For that, we designed an automatic control of connections in the VNC system that can be operated remotely over the network. We also suggested an interface that assigns a role such as “Screen sender" or “Screen receiver" to each terminal. In the proposed system, while sharing a screen between multiple terminals, one can easily display and browse the screen without having to understand how the others are connected. We also implemented a “role card" using contactless IC card, where roles are assigned only by placing the card in the IC reader.

  2. Grid-Connected Photovoltaic System with Active Power Filtering Functionality

    Directory of Open Access Journals (Sweden)

    Joaquín Vaquero

    2018-01-01

    Full Text Available Solar panels are an attractive and growing source of renewable energy in commercial and residential applications. Its use connected to the grid by means of a power converter results in a grid-connected photovoltaic system. In order to optimize this system, it is interesting to integrate several functionalities into the power converter, such as active power filtering and power factor correction. Nonlinear loads connected to the grid generate current harmonics, which deteriorates the mains power quality. Active power filters can compensate these current harmonics. A photovoltaic system with added harmonic compensation and power factor correction capabilities is proposed in this paper. A sliding mode controller is employed to control the power converter, implemented on the CompactRIO digital platform from National Instruments Corporation, allowing user friendly operation and easy tuning. The power system consists of two stages, a DC/DC boost converter and a single-phase inverter, and it is able to inject active power into the grid while compensating the current harmonics generated by nonlinear loads at the point of common coupling. The operation, design, simulation, and experimental results for the proposed system are discussed.

  3. Global distribution of grid connected electrical energy storage systems

    Directory of Open Access Journals (Sweden)

    Katja Buss

    2016-06-01

    Full Text Available This article gives an overview of grid connected electrical energy storage systems worldwide, based on public available data. Technologies considered in this study are pumped hydroelectric energy storage (PHES, compressed air energy storage (CAES, sodium-sulfur batteries (NaS, lead-acid batteries, redox-flow batteries, nickel-cadmium batteries (NiCd and lithium-ion batteries. As the research indicates, the worldwide installed capacity of grid connected electrical energy storage systems is approximately 154 GW. This corresponds to a share of 5.5 % of the worldwide installed generation capacity. Furthermore, the article gives an overview of the historical development of installed and used storage systems worldwide. Subsequently, the focus is on each considered technology concerning the current storage size, number of plants and location. In summary it can be stated, PHES is the most commonly used technology worldwide, whereas electrochemical technologies are increasingly gaining in importance. Regarding the distribution of grid connected storage systems reveals the share of installed storage capacity is in Europe and Eastern Asia twice as high as in North America.

  4. Integrating Resources into Curriculum with the Systems Connect Planning Guide

    Science.gov (United States)

    Oshry, A.; Bean, J. R.

    2017-12-01

    A broadly applicable and guided approach for planning curriculum and instruction around new academic standards or initiatives is critical for implementation success. Curriculum and assessment differs across schools and districts, so built-in adaptability is important for maximal adoption and ease of use by educators. The Systems Connect Planning Guide directs the flow of instruction for building conceptual links between topics in a unit/curriculum through critical vetting and integration of relevant resources. This curricular template is flexible for use in any setting or subject area, and ensures applicability, high impact and responsiveness to academic standards while providing inquiry-based, real-world investigations and action that incorporate authentic research and data. These needs are what informed the creation of the three components of the planning guide:• Curriculum Anchor: alignment with academic standards & learning outcomes and setting the context of the topic• Issues Investigations: informing how students explore topics, and incorporate authentic research and data into learning progressions• Civic Action: development of how students could apply their knowledgeThe Planning Guide also incorporates criteria from transdisciplinary practices, cross-cutting concepts, and organizational charts for outlining guiding questions and conceptual links embedded in the guide. Integration of experiential learning and real-world connections into curricula is important for proficiency and deeper understanding of content, replacing discrete, stand-alone experiences which are not explicitly connected. Rather than information being dispelled through individual activities, relying on students to make the connections, intentionally documenting explicit connections provides opportunities to foster deeper understanding by building conceptual links between topics, which is how fundamental knowledge about earth and living systems is gained. Through the critical vetting

  5. Control of Grid Connected Photovoltaic Systems with Microinverters

    DEFF Research Database (Denmark)

    Yahya, Abdelhafid; El Fadil, Hassan; Oulcaid, Mustapha

    2018-01-01

    This paper addresses the problem of controlling grid connected photovoltaic (PV) systems that are driven with microinverters. The systems to be controlled consist of a solar panel, a boost dc–dc converter, a DC link capacitor, a single-phase full-bridge inverter, a filter inductor, and an isolation...... transformer. We seek controllers that are able to simultaneously achieve four control objectives, namely: (i) asymptotic stability of the closed loop control system; (ii) maximum power point tracking (MPPT) of the PV module; (iii) tight regulation of the DC bus voltage; and (iv) unity power factor (PF...

  6. Modern Embedded Computing Designing Connected, Pervasive, Media-Rich Systems

    CERN Document Server

    Barry, Peter

    2012-01-01

    Modern embedded systems are used for connected, media-rich, and highly integrated handheld devices such as mobile phones, digital cameras, and MP3 players. All of these embedded systems require networking, graphic user interfaces, and integration with PCs, as opposed to traditional embedded processors that can perform only limited functions for industrial applications. While most books focus on these controllers, Modern Embedded Computing provides a thorough understanding of the platform architecture of modern embedded computing systems that drive mobile devices. The book offers a comprehen

  7. Systemic connective tissue features in women with fibromuscular dysplasia.

    Science.gov (United States)

    O'Connor, Sarah; Kim, Esther Sh; Brinza, Ellen; Moran, Rocio; Fendrikova-Mahlay, Natalia; Wolski, Kathy; Gornik, Heather L

    2015-10-01

    Fibromuscular dysplasia (FMD) is a non-atherosclerotic disease associated with hypertension, headache, dissection, stroke, and aneurysm. The etiology is unknown but hypothesized to involve genetic and environmental components. Previous studies suggest a possible overlap of FMD with other connective tissue diseases that present with dissections and aneurysms. The aim of this study was to investigate the prevalence of connective tissue physical features in FMD. A total of 142 FMD patients were consecutively enrolled at a single referral center (97.9% female, 92.1% of whom had multifocal FMD). Data are reported for 139 female patients. Moderately severe myopia (29.1%), high palate (33.1%), dental crowding (29.7%), and early-onset arthritis (15.6%) were prevalent features. Classic connective features such as hypertelorism, cleft palate, and hypermobility were uncommon. The frequency of systemic connective tissue features was compared between FMD patients with a high vascular risk profile (having had ⩾1 dissection and/or ⩾2 aneurysms) and those with a standard vascular risk profile. A history of spontaneous pneumothorax (5.9% high risk vs 0% standard risk) and atrophic scarring (17.6% high risk vs 6.8% standard risk) were significantly more prevalent in the high risk group, pconnective tissue features such as high palate and pneumothorax were more prominent among FMD patients with a high vascular risk profile. © The Author(s) 2015.

  8. Comparative Analysis of Inversors for Small PV Systems Grid Connected

    International Nuclear Information System (INIS)

    Sidrach de Cardona, M.; Ramirez, L.

    2001-01-01

    The energy produced by a grid connected photovoltaic system is a function of weather conditions, mainly available radiation and temperature, photovoltaic array efficiency and inverter characteristics. The results obtained in experimental measurements with four small grid-connected inverters are described in this work. The main goal is to know the inverter performance in real operation conditions. For this purpose a 2 kW photovoltaic system has been used. These results allow us to know both the inverter efficiency and its output power quality. The following parameters have been evaluated as a function of output inverter power: efficiency, point of maximum power tracking, intensity and voltage waveform, total harmonic distortion and harmonic values to 31 order, frequency, power factor and reactive power. Other interesting parameters like stand-by energy consumption and daily losses due to the inverter threshold have also been analyzed. The results allow us to know the inverter features as a function of its real work point. In our comparative study it is possible to observe remarkable differences between the inverters; these results show how important it is to have a unique standard for inverters to photovoltaic grid-connected systems. (Author) 10 refs

  9. Initial Development of an Electronic Testis Rigidity Tester

    Directory of Open Access Journals (Sweden)

    Petros Mirilas

    2011-01-01

    Full Text Available We aimed to develop our previously presented mechanical device, the Testis Rigidity Tester (TRT, into an electronic system (Electronic Testis Rigidity Tester, ETRT by applying tactile imaging, which has been used successfully with other solid organs. A measuring device, located at the front end of the ETRT incorporates a tactile sensor comprising an array of microsensors. By application of a predetermined deformation of 2 mm, increased pressure alters linearly the resistance of each microsensor, producing changes of voltage. These signals were amplified, filtered, and digitized, and then processed by an electronic collector system, which presented them as a color-filled contour plot of the area of the testis coming into contact with the sensor. Testis models of different rigidity served for initial evaluation of ETRT; their evacuated central spaces contained different, increasing glue masses. An independent method of rigidity measurement, using an electric weight scale and a micrometer, showed that the more the glue injected, the greater the force needed for a 2-mm deformation. In a preliminary test, a single sensor connected to a multimeter showed similar force measurement for the same deformation in these phantoms. For each of the testis models compressed in the same manner, the ETRT system offered a map of pressures, represented by a color scale within the contour plot of the contact area with the sensor. ETRT found certain differences in rigidity between models that had escaped detection by a blind observer. ETRT is easy to use and provides a color-coded “insight“ of the testis internal structure. After experimental testing, it could be valuable in intraoperative evaluation of testes, so that the surgeon can decide about orchectomy or orcheopexy.

  10. Cooling system for the connecting rings of a fast neutron reactor vessel

    International Nuclear Information System (INIS)

    Martin, J.-P.; Malaval, Claude

    1974-01-01

    A description is given of a cooling system for the vessel connecting rings of a fast neutron nuclear reactor, particularly of a main vessel containing the core of the reactor and a volume of liquid metal coolant at high temperature and a safety vessel around the main vessel, both vessels being suspended to a rigid upper slab kept at a lower temperature. It is mounted in the annular space between the two vessels and includes a neutral gas circuit set up between the wall of the main vessel to be cooled and that of the safety vessel itself cooled from outer. The neutral gas system comprises a plurality of ventilators fitted in holes made through the thickness of the upper slab and opening on to the space between the two vessels. It also includes two envelopes lining the walls of these vessels, establishing with them small section channels for the circulation of the neutral gas cooled against the safety vessel and heated against the main vessel [fr

  11. Establishment of key grid-connected performance index system for integrated PV-ES system

    Science.gov (United States)

    Li, Q.; Yuan, X. D.; Qi, Q.; Liu, H. M.

    2016-08-01

    In order to further promote integrated optimization operation of distributed new energy/ energy storage/ active load, this paper studies the integrated photovoltaic-energy storage (PV-ES) system which is connected with the distribution network, and analyzes typical structure and configuration selection for integrated PV-ES generation system. By combining practical grid- connected characteristics requirements and technology standard specification of photovoltaic generation system, this paper takes full account of energy storage system, and then proposes several new grid-connected performance indexes such as paralleled current sharing characteristic, parallel response consistency, adjusting characteristic, virtual moment of inertia characteristic, on- grid/off-grid switch characteristic, and so on. A comprehensive and feasible grid-connected performance index system is then established to support grid-connected performance testing on integrated PV-ES system.

  12. Quantum mechanics of a generalised rigid body

    International Nuclear Information System (INIS)

    Gripaios, Ben; Sutherland, Dave

    2016-01-01

    We consider the quantum version of Arnold’s generalisation of a rigid body in classical mechanics. Thus, we quantise the motion on an arbitrary Lie group manifold of a particle whose classical trajectories correspond to the geodesics of any one-sided-invariant metric. We show how the derivation of the spectrum of energy eigenstates can be simplified by making use of automorphisms of the Lie algebra and (for groups of type I) by methods of harmonic analysis. We show how the method can be extended to cosets, generalising the linear rigid rotor. As examples, we consider all connected and simply connected Lie groups up to dimension 3. This includes the universal cover of the archetypical rigid body, along with a number of new exactly solvable models. We also discuss a possible application to the topical problem of quantising a perfect fluid. (paper)

  13. Coping with System Failure: Why Connectivity Matters to Innovation Policy

    DEFF Research Database (Denmark)

    Ricard, Lykke Margot

    2015-01-01

    system to create new institutional structures in the economy. A major social network analysis examines how connectivity in two specific European ‘technology’ platforms’ networks has changed and evolved in relation to researching the solutions to solving major societal problems, and therefore has also...... it to reach its climate goals for 2020. The chapter’s research strategy stresses the importance of relations rather than the determinism of technology or ideas. As a result, the chapter’s structural analysis shows how firms in the modern European economy work, on a collective level, from within the political...... driven innovation towards new business opportunities. The analysis shows how connectivity and network relations play an important role in innovation, as opposed to arm-length anonymous interactions as presumed in mainstream economic thinking....

  14. Traffic Congestion Detection System through Connected Vehicles and Big Data.

    Science.gov (United States)

    Cárdenas-Benítez, Néstor; Aquino-Santos, Raúl; Magaña-Espinoza, Pedro; Aguilar-Velazco, José; Edwards-Block, Arthur; Medina Cass, Aldo

    2016-04-28

    This article discusses the simulation and evaluation of a traffic congestion detection system which combines inter-vehicular communications, fixed roadside infrastructure and infrastructure-to-infrastructure connectivity and big data. The system discussed in this article permits drivers to identify traffic congestion and change their routes accordingly, thus reducing the total emissions of CO₂ and decreasing travel time. This system monitors, processes and stores large amounts of data, which can detect traffic congestion in a precise way by means of a series of algorithms that reduces localized vehicular emission by rerouting vehicles. To simulate and evaluate the proposed system, a big data cluster was developed based on Cassandra, which was used in tandem with the OMNeT++ discreet event network simulator, coupled with the SUMO (Simulation of Urban MObility) traffic simulator and the Veins vehicular network framework. The results validate the efficiency of the traffic detection system and its positive impact in detecting, reporting and rerouting traffic when traffic events occur.

  15. Birationally rigid varieties. I. Fano varieties

    International Nuclear Information System (INIS)

    Pukhlikov, A V

    2007-01-01

    The theory of birational rigidity of rationally connected varieties generalises the classical rationality problem. This paper gives a survey of the current state of this theory and traces its history from Noether's theorem and the Lueroth problem to the latest results on the birational superrigidity of higher-dimensional Fano varieties. The main components of the method of maximal singularities are considered.

  16. Security credentials management system (SCMS) design and analysis for the connected vehicle system : draft.

    Science.gov (United States)

    2013-12-27

    This report presents an analysis by Booz Allen Hamilton (Booz Allen) of the technical design for the Security Credentials Management System (SCMS) intended to support communications security for the connected vehicle system. The SCMS technical design...

  17. An Explicit Formulation of Singularity-Free Dynamic Equations of Mechanical Systems in Lagrangian Form---Part one: Single Rigid Bodies

    Directory of Open Access Journals (Sweden)

    Pål Johan From

    2012-04-01

    Full Text Available This paper presents the explicit dynamic equations of a mechanical system. The equations are presented so that they can easily be implemented in a simulation software or controller environment and are also well suited for system and controller analysis. The dynamics of a general mechanical system consisting of one or more rigid bodies can be derived from the Lagrangian. We can then use several well known properties of Lie groups to guarantee that these equations are well defined. This will, however, often lead to rather abstract formulation of the dynamic equations that cannot be implemented in a simulation software directly. In this paper we close this gap and show what the explicit dynamic equations look like. These equations can then be implemented directly in a simulation software and no background knowledge on Lie theory and differential geometry on the practitioner's side is required. This is the first of two papers on this topic. In this paper we derive the dynamics for single rigid bodies, while in the second part we study multibody systems. In addition to making the equations more accessible to practitioners, a motivation behind the papers is to correct a few errors commonly found in literature. For the first time, we show the detailed derivations and how to arrive at the correct set of equations. We also show through some simple examples that these correspond with the classical formulations found from Lagrange's equations. The dynamics is derived from the Boltzmann--Hamel equations of motion in terms of local position and velocity variables and the mapping to the corresponding quasi-velocities. Finally we present a new theorem which states that the Boltzmann--Hamel formulation of the dynamics is valid for all transformations with a Lie group topology. This has previously only been indicated through examples, but here we also present the formal proof. The main motivation of these papers is to allow practitioners not familiar with

  18. Distributed control system for parallel-connected DC boost converters

    Science.gov (United States)

    Goldsmith, Steven

    2017-08-15

    The disclosed invention is a distributed control system for operating a DC bus fed by disparate DC power sources that service a known or unknown load. The voltage sources vary in v-i characteristics and have time-varying, maximum supply capacities. Each source is connected to the bus via a boost converter, which may have different dynamic characteristics and power transfer capacities, but are controlled through PWM. The invention tracks the time-varying power sources and apportions their power contribution while maintaining the DC bus voltage within the specifications. A central digital controller solves the steady-state system for the optimal duty cycle settings that achieve a desired power supply apportionment scheme for a known or predictable DC load. A distributed networked control system is derived from the central system that utilizes communications among controllers to compute a shared estimate of the unknown time-varying load through shared bus current measurements and bus voltage measurements.

  19. Performance Analysis of 14 MW Grid-Connected Photovoltaic System

    International Nuclear Information System (INIS)

    Kagilik, Ahmed S.; Tawel, Abduraouf M.

    2015-01-01

    Many Libyan authorities proposed to investigate the possibility of utilizing a suitable terrain in Libya to add generation capacity of large-scale photovoltaic power plants. In this paper, the first grid-connected PV plant of 14 MWp which will be executed in Hoon city and supported by the Renewable Energy Authority of Libya (REAOL) is presented. To understand and improve the operational behavior of PV system, a comprehensive study including the plant design and detailed performance analysis under a local climate conditions is performed. Using polycrystalline silicon technology, the first year energy yield is estimated and the monthly system output for this plant is calculated. The performance ratio and various power losses (temperature, irradiance, power electronics, interconnection, etc.) are determined. The PV system supplied 24964 MWh to the grid during the first year giving an average annual overall yield factor 1783 kWh/kWp and average annual performance ratio of the system of 76.9%.(author)

  20. The German experience with grid-connected PV-systems

    International Nuclear Information System (INIS)

    Erge, T.; Hoffmann, V.U.; Kiefer, K.

    2001-01-01

    Grid-connected photovoltaics experienced increasing attention in Germany in recent years and are expected to face a major boost at the beginning of the new millennium. Highlights like the German 100,000-Roofs-Solar-Programme, PV programmes at schools financed by utilities and governments (e.g. 'SONNEonline' by PreussenElektra, 'Sonne in der Schule' by BMWi and 'Sonne in der Schule' by Bayernwerk) and large centralised installations of MW size ('Neue Messe Munchen' by Bayernwerk and 'Energiepark Mont-Cenis' by state Nordrhein-Westfalen, Stadtwerke Herne and European Union) count for the potential of grid-connected PV. Today in Germany a typical grid-connected PV installation of 1 kW nominal power produces average annual energy yields of 700 kWh (dependent on location and system components) and shows a high operating availability. The price per kWh from PV installations is still significantly higher than the price for conventional energy, but new funding schemes and cost models (like the large increase of feed-in tariff in Germany due to the Act on Granting Priority to Renewable Energy Sources in 2000) give optimism about the future. (Author)

  1. 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.

  2. Quantum charged rigid membrane

    Energy Technology Data Exchange (ETDEWEB)

    Cordero, Ruben [Departamento de Fisica, Escuela Superior de Fisica y Matematicas del I.P.N., Unidad Adolfo Lopez Mateos, Edificio 9, 07738 Mexico, D.F. (Mexico); Molgado, Alberto [Unidad Academica de Fisica, Universidad Autonoma de Zacatecas, Zacatecas Zac. (Mexico); Rojas, Efrain, E-mail: cordero@esfm.ipn.mx, E-mail: amolgado@fisica.uaz.edu.mx, E-mail: efrojas@uv.mx [Departamento de Fisica, Facultad de Fisica e Inteligencia Artificial, Universidad Veracruzana, 91000 Xalapa, Veracruz (Mexico)

    2011-03-21

    The early Dirac proposal to model the electron as a charged membrane is reviewed. A rigidity term, instead of the natural membrane tension, involving linearly the extrinsic curvature of the worldvolume swept out by the membrane is considered in the action modeling the bubble in the presence of an electromagnetic field. We set up this model as a genuine second-order derivative theory by considering a non-trivial boundary term which plays a relevant part in our formulation. The Lagrangian in question is linear in the bubble acceleration and by means of the Ostrogradski-Hamiltonian approach, we observed that the theory comprises the management of both first- and second-class constraints. We thus show that our second-order approach is robust allowing for a proper quantization. We found an effective quantum potential which permits us to compute bounded states for the system. We comment on the possibility of describing brane world universes by invoking this kind of second-order correction terms.

  3. Quantum charged rigid membrane

    International Nuclear Information System (INIS)

    Cordero, Ruben; Molgado, Alberto; Rojas, Efrain

    2011-01-01

    The early Dirac proposal to model the electron as a charged membrane is reviewed. A rigidity term, instead of the natural membrane tension, involving linearly the extrinsic curvature of the worldvolume swept out by the membrane is considered in the action modeling the bubble in the presence of an electromagnetic field. We set up this model as a genuine second-order derivative theory by considering a non-trivial boundary term which plays a relevant part in our formulation. The Lagrangian in question is linear in the bubble acceleration and by means of the Ostrogradski-Hamiltonian approach, we observed that the theory comprises the management of both first- and second-class constraints. We thus show that our second-order approach is robust allowing for a proper quantization. We found an effective quantum potential which permits us to compute bounded states for the system. We comment on the possibility of describing brane world universes by invoking this kind of second-order correction terms.

  4. Optoelectronic system and apparatus for connection to biological systems

    Science.gov (United States)

    Okandan, Murat; Nielson, Gregory N.

    2018-03-06

    The present invention relates to a biological probe structure, as well as apparatuses, systems, and methods employing this structure. In particular embodiments, the structure includes a hermetically sealed unit configured to receive and transmit one or more optical signals. Furthermore, the structure can be implanted subcutaneously and interrogated externally. In this manner, a minimally invasive method can be employed to detect, treat, and/or assess the biological target. Additional methods and systems are also provided.

  5. Rigid body dynamics of mechanisms

    CERN Document Server

    Hahn, Hubert

    2003-01-01

    The second volume of Rigid Body Dynamics of Mechanisms covers applications via a systematic method for deriving model equations of planar and spatial mechanisms. The necessary theoretical foundations have been laid in the first volume that introduces the theoretical mechanical aspects of mechatronic systems. Here the focus is on the application of the modeling methodology to various examples of rigid-body mechanisms, simple planar ones as well as more challenging spatial problems. A rich variety of joint models, active constraints, plus active and passive force elements is treated. The book is intended for self-study by working engineers and students concerned with the control of mechanical systems, i.e. robotics, mechatronics, vehicles, and machine tools. The examples included are a likely source from which to choose models for university lectures.

  6. Solvent-assisted multistage nonequilibrium electron transfer in rigid supramolecular systems: Diabatic free energy surfaces and algorithms for numerical simulations

    Science.gov (United States)

    Feskov, Serguei V.; Ivanov, Anatoly I.

    2018-03-01

    An approach to the construction of diabatic free energy surfaces (FESs) for ultrafast electron transfer (ET) in a supramolecule with an arbitrary number of electron localization centers (redox sites) is developed, supposing that the reorganization energies for the charge transfers and shifts between all these centers are known. Dimensionality of the coordinate space required for the description of multistage ET in this supramolecular system is shown to be equal to N - 1, where N is the number of the molecular centers involved in the reaction. The proposed algorithm of FES construction employs metric properties of the coordinate space, namely, relation between the solvent reorganization energy and the distance between the two FES minima. In this space, the ET reaction coordinate zn n' associated with electron transfer between the nth and n'th centers is calculated through the projection to the direction, connecting the FES minima. The energy-gap reaction coordinates zn n' corresponding to different ET processes are not in general orthogonal so that ET between two molecular centers can create nonequilibrium distribution, not only along its own reaction coordinate but along other reaction coordinates too. This results in the influence of the preceding ET steps on the kinetics of the ensuing ET. It is important for the ensuing reaction to be ultrafast to proceed in parallel with relaxation along the ET reaction coordinates. Efficient algorithms for numerical simulation of multistage ET within the stochastic point-transition model are developed. The algorithms are based on the Brownian simulation technique with the recrossing-event detection procedure. The main advantages of the numerical method are (i) its computational complexity is linear with respect to the number of electronic states involved and (ii) calculations can be naturally parallelized up to the level of individual trajectories. The efficiency of the proposed approach is demonstrated for a model

  7. An Efficient Connected Component Labeling Architecture for Embedded Systems

    Directory of Open Access Journals (Sweden)

    Fanny Spagnolo

    2018-03-01

    Full Text Available Connected component analysis is one of the most fundamental steps used in several image processing systems. This technique allows for distinguishing and detecting different objects in images by assigning a unique label to all pixels that refer to the same object. Most of the previous published algorithms have been designed for implementation by software. However, due to the large number of memory accesses and compare, lookup, and control operations when executed on a general-purpose processor, they do not satisfy the speed performance required by the next generation high performance computer vision systems. In this paper, we present the design of a new Connected Component Labeling hardware architecture suitable for high performance heterogeneous image processing of embedded designs. When implemented on a Zynq All Programmable-System on Chip (AP-SOC 7045 chip, the proposed design allows a throughput rate higher of 220 Mpixels/s to be reached using less than 18,000 LUTs and 5000 FFs, dissipating about 620 μJ.

  8. Birationally rigid varieties

    CERN Document Server

    Pukhlikov, Aleksandr

    2013-01-01

    Birational rigidity is a striking and mysterious phenomenon in higher-dimensional algebraic geometry. It turns out that certain natural families of algebraic varieties (for example, three-dimensional quartics) belong to the same classification type as the projective space but have radically different birational geometric properties. In particular, they admit no non-trivial birational self-maps and cannot be fibred into rational varieties by a rational map. The origins of the theory of birational rigidity are in the work of Max Noether and Fano; however, it was only in 1970 that Iskovskikh and Manin proved birational superrigidity of quartic three-folds. This book gives a systematic exposition of, and a comprehensive introduction to, the theory of birational rigidity, presenting in a uniform way, ideas, techniques, and results that so far could only be found in journal papers. The recent rapid progress in birational geometry and the widening interaction with the neighboring areas generate the growing interest ...

  9. On flexible and rigid nouns

    DEFF Research Database (Denmark)

    Rijkhoff, Jan

    2008-01-01

    Studies in Language 32-3 (2008), 727-752. Special issue: Parts of Speech: Descriptive tools, theoretical constructs Jan Rijkhoff - On flexible and rigid nouns This article argues that in addition to the flexible lexical categories in Hengeveld’s classification of parts-of-speech systems (Contentive......, Non-Verb, Modifier), there are also flexible word classes within the rigid lexical category Noun (Set Noun, Sort Noun, General Noun). Members of flexible word classes are characterized by their vague semantics, which in the case of nouns means that values for the semantic features Shape...... and Homogeneity are either left undetermined or they are specified in such a way that they do not quite match the properties of the kind of entity denoted by the flexible item in the external world. I will then argue that flexible word classes constitute a proper category (i.e. they are not the result of a merger...

  10. Thermal fatigue evaluation of piping system Tee-connections

    International Nuclear Information System (INIS)

    Metzner, K.J.; Braillard, O.; Faidy, C.; Marcelles, I.; Solin, J.; Stumpfrock, L.

    2004-01-01

    Thermal fatigue is one significant long-term degradation mechanism nuclear power plants (NPP), in particular, as operating plants become older and life time extension activities have been initiated. In general, the common thermal fatigue issues are understood and controlled by plant instrumentation systems. However, incidents in some plants indicate that certain piping system Tees are susceptible to turbulent temperature mixing effects that cannot be adequately monitored by common thermocouple instrumentation. The THERFAT project has been initiated to advance the accuracy and reliability of thermal fatigue load determination in engineering tools and research oriented approaches to outline a science based practical methodology for managing thermal fatigue risks in Tee-connections susceptible to high cyclic thermal fatigue. (orig.)

  11. Optimising the economic viability of grid-connected photovoltaic systems

    International Nuclear Information System (INIS)

    Mondol, Jayanta Deb; Yohanis, Yigzaw G; Norton, Brian

    2009-01-01

    The impact of photovoltaic (PV) array size, orientation, inclination, load profile, electricity buying price, feed-in tariffs, PV/inverter sizing ratio ('sizing ratio') and PV/inverter cost ratio ('cost ratio') on the economic viability of a grid-connected PV system was investigated using a validated TRNSYS simulation model. The results showed that the fractional load met directly by a PV system depends on matching between PV supply and building load profile, sizing ratio and PV inclination. The profitability of a grid-connected PV system increases if the PV system is sized to reduce excess PV electrical energy fed to the grid when the feed-in tariff is lower than electricity buying price. The effect of feed-in tariffs on PV saving for selected European countries has been shown. The cost of the PV electricity depends on sizing ratio, PV and inverter lifetimes, cost ratio, PV inclination and financial parameters. The effect of cost ratio on the optimum PV/inverter sizing ratio is less significant when the cost ratio lies within 7-11. The minimum PV electricity cost at low and high insolation conditions were obtained for sizing ratios of 1.6 and 1.2, respectively. The lowest PV electricity cost was found for surface slopes within 30-40 for the selected European locations. The PV electricity cost for cost ratio of 5 and 13 varied from 0.44-0.85 EURkWh -1 to 0.38-0.76 EURkWh -1 , respectively within high to low insolation conditions when the PV module unit cost, market discount rate, PV size, PV lifetime and inverter lifetime were assumed to be 6.5 EURW p -1 , 3%, 13 kW p , 20 years and 10 years, respectively. (author)

  12. Intermittently Connected Cloudlet System to Obtain an Optimal Offloading Policy

    Directory of Open Access Journals (Sweden)

    Nadim Akhtar

    2016-09-01

    Full Text Available The great potential has been shown over the performance enhancement for offloading the mobile devices within intensive parts of computation within mobile cloud application. The complete realization for the potential which being mismatch within the particular mobile devices on the resource computing demand and that provide an offer. The request over offloading is connecting the variable network where cloud services are always being in the required process within infrequent, variable connectivity of network and quick response time for relatively incurring the times for long setup and quanta for long time are may be indifferent for the connectivity of network. The requirement over the mobile application is needed more resources for executing the single device task within the fact of mobile devices enhanced capabilities. The problems have been addressed for several computation of offloading the remote cloud services and resources which is locating the computing resources in the cloudlets. The proposed concept is proposing an experimental approach for highlighting the tradeoff of offloading. The proposed architecture of the generic algorithm is performing an integration of mobile cloud computing for automatic offloading to improve the application response time when minimizing the consumption of energy for mobile device. Offloading task within a remote machine is not better than performing task particularly. The particular performance of the task is always better than remote machine. The proposed system is developing an algorithm of optimal offloading for mobile user which considering over the cloudlets availability and local load of user’s. The solution and formulation of the MDP (Markov Decision Process model is for obtaining a policy to the user mobile and minimizing the objective of offloading cost and computation cost.

  13. Macaque accessory optic system: II. Connections with the pretectum

    International Nuclear Information System (INIS)

    Baleydier, C.; Magnin, M.; Cooper, H.M.

    1990-01-01

    Connections of the accessory optic system (AOS) with the pretectum are described in the macaque monkey. Injections of tritiated amino acids in the pretectum demonstrate a major contralateral projection to the dorsal (DTN), lateral (LTN), and medial (MTN) terminal nuclei of the AOS and a sparser projection to the ipsilateral LTN. Injections of retrograde tracers, Fast Blue (FB), or wheat germ agglutinin horseradish peroxidase (WGA-HRP) plus nonconjugated horseradish peroxidase (HRP) in the LTN show that the pretectal-LTN projection originates from two nuclei. The main source of pretectal efferents to the LTN is from the pretectal olivary nucleus (OPN) and is entirely contralateral. This projection, which appears unique to primates, originates from the large multipolar cells of the OPN. In addition to this projection, the nucleus of the optic tract (NOT) projects to the ipsilateral LTN, as in nonprimates. Injection of WGA-HRP in the pretectum shows a reciprocal predominantely ipsilateral projection from the LTN to the pretectum. Retinas were observed after injection of FB in the LTN. The retinal ganglion cells projecting to the AOS are mainly distributed near the fovea and in the nasal region of the contralateral eye, suggesting a nasotemporal pattern of decussation. The demonstration of a direct connection between LTN and OPN forces to a reconsideration of the functional role of the AOS. Previous descriptions of luminance responsive cells in the LTN support a possible participation of this nucleus in the control of the pupillary light reflex

  14. Traffic Congestion Detection System through Connected Vehicles and Big Data

    Directory of Open Access Journals (Sweden)

    Néstor Cárdenas-Benítez

    2016-04-01

    Full Text Available This article discusses the simulation and evaluation of a traffic congestion detection system which combines inter-vehicular communications, fixed roadside infrastructure and infrastructure-to-infrastructure connectivity and big data. The system discussed in this article permits drivers to identify traffic congestion and change their routes accordingly, thus reducing the total emissions of CO2 and decreasing travel time. This system monitors, processes and stores large amounts of data, which can detect traffic congestion in a precise way by means of a series of algorithms that reduces localized vehicular emission by rerouting vehicles. To simulate and evaluate the proposed system, a big data cluster was developed based on Cassandra, which was used in tandem with the OMNeT++ discreet event network simulator, coupled with the SUMO (Simulation of Urban MObility traffic simulator and the Veins vehicular network framework. The results validate the efficiency of the traffic detection system and its positive impact in detecting, reporting and rerouting traffic when traffic events occur.

  15. Analysis of Switched-Rigid Floating Oscillator

    Directory of Open Access Journals (Sweden)

    Prabhakar R. Marur

    2009-01-01

    Full Text Available In explicit finite element simulations, a technique called deformable-to-rigid (D2R switching is used routinely to reduce the computation time. Using the D2R option, the deformable parts in the model can be switched to rigid and reverted back to deformable when needed during the analysis. The time of activation of D2R however influences the overall dynamics of the system being analyzed. In this paper, a theoretical basis for the selection of time of rigid switching based on system energy is established. A floating oscillator problem is investigated for this purpose and closed-form analytical expressions are derived for different phases in rigid switching. The analytical expressions are validated by comparing the theoretical results with numerical computations.

  16. Connectivity and systemic resilience of the Great Barrier Reef.

    Directory of Open Access Journals (Sweden)

    Karlo Hock

    2017-11-01

    Full Text Available Australia's iconic Great Barrier Reef (GBR continues to suffer from repeated impacts of cyclones, coral bleaching, and outbreaks of the coral-eating crown-of-thorns starfish (COTS, losing much of its coral cover in the process. This raises the question of the ecosystem's systemic resilience and its ability to rebound after large-scale population loss. Here, we reveal that around 100 reefs of the GBR, or around 3%, have the ideal properties to facilitate recovery of disturbed areas, thereby imparting a level of systemic resilience and aiding its continued recovery. These reefs (1 are highly connected by ocean currents to the wider reef network, (2 have a relatively low risk of exposure to disturbances so that they are likely to provide replenishment when other reefs are depleted, and (3 have an ability to promote recovery of desirable species but are unlikely to either experience or spread COTS outbreaks. The great replenishment potential of these 'robust source reefs', which may supply 47% of the ecosystem in a single dispersal event, emerges from the interaction between oceanographic conditions and geographic location, a process that is likely to be repeated in other reef systems. Such natural resilience of reef systems will become increasingly important as the frequency of disturbances accelerates under climate change.

  17. Solar System Connections to the Organic Material In the ISM

    Science.gov (United States)

    Pendleton, Yvonne J.

    2003-01-01

    The organic component of the interstellar medium (ISM) has relevance to the formation of the early solar nebula, since our solar system formed out of ISM material. Comparisons of near infrared spectra of the diffuse ISM dust with those of primitive solar system bodies (such as comets and meteorites) show a remarkable similarity, suggesting that perhaps some of the interstellar organic material made its way, unaltered, into our solar system. Tracing the interstellar organic material is necessary to understand how these materials may be important links in the development of prebiotic phenomena. Studies of the ISM reveal that the organic refractory component of the diffuse ISM is largely hydrocarbon in nature, possessing little N or O, with carbon distributed between the aromatic and aliphatic forms. There is a strong similarity in the near IR spectra of the diffuse ISM (the 3.4 micron hydrocarbon bands) and those seen in the Murchison and Orgueil meteorites, however, detailed comparisons at longer wavelengths reveal critical dissimilarities. Here we will present comparisons and discussion of relevant spectra. As we continue to explore, we will gain insight into the connection between planetesimals in the solar system and chemistry in the dusty space between the stars.

  18. Estimating time-dependent connectivity in marine systems

    Science.gov (United States)

    Defne, Zafer; Ganju, Neil K.; Aretxabaleta, Alfredo

    2016-01-01

    Hydrodynamic connectivity describes the sources and destinations of water parcels within a domain over a given time. When combined with biological models, it can be a powerful concept to explain the patterns of constituent dispersal within marine ecosystems. However, providing connectivity metrics for a given domain is a three-dimensional problem: two dimensions in space to define the sources and destinations and a time dimension to evaluate connectivity at varying temporal scales. If the time scale of interest is not predefined, then a general approach is required to describe connectivity over different time scales. For this purpose, we have introduced the concept of a “retention clock” that highlights the change in connectivity through time. Using the example of connectivity between protected areas within Barnegat Bay, New Jersey, we show that a retention clock matrix is an informative tool for multitemporal analysis of connectivity.

  19. The oral-systemic disease connection: a retrospective study.

    Science.gov (United States)

    Joseph, Bobby K; Kullman, Leif; Sharma, Prem N

    2016-11-01

    The study aimed at determining the association between oral disease and systemic health based on panoramic radiographs and general health of patients treated at Kuwait University Dental Center. The objective was to determine whether individuals exhibiting good oral health have lower propensity to systemic diseases. A total of 1000 adult patients treated at Kuwait University Dental Center were randomly selected from the patient's records. The general health of patients was assessed from the medical history of each patient recorded during their visit to the clinic. The number of reported diseases and serious symptoms were used to develop a medical index. The oral health of these patients was assessed from panoramic radiographs to create an oral index by evaluating such parameters as caries, periodontitis, periapical lesions, pericoronitis, and tooth loss. In a total of 887 patients, 43.8 % had an oral index between 3 and 8, of which significantly higher (62.1 %) patients were with medical conditions compared to those without (33.2 %; p relationship when the diagnosis of oral disease was based primarily on radiographic findings. Future research needs to include prospective clinical and interventional studies. The significance of the oral-systemic disease connection highlights the importance of preventing and treating oral disease which have profound medical implications on general health.

  20. Soft soils reinforced by rigid vertical inclusions

    Directory of Open Access Journals (Sweden)

    Iulia-Victoria NEAGOE

    2013-12-01

    Full Text Available Reinforcement of soft soils by rigid vertical inclusions is an increasingly used technique over the last few years. The system consists of rigid or semi-rigid vertical inclusions and a granular platform for the loads transfer from the structure to the inclusions. This technique aims to reduce the differential settlements both at ground level as below the structure. Reinforcement by rigid inclusions is mainly used for foundation works for large commercial and industrial platforms, storage tanks, wastewater treatment plants, wind farms, bridges, roads, railway embankments. The subject is one of interest as it proves the recently concerns at international level in research and design; however, most studies deal more with the static behavior and less with the dynamic one.

  1. Rigid supersymmetry with boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Belyaev, D.V. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Van Nieuwenhuizen, P. [State Univ. of New York, Stony Brook, NY (United States). C.N. Yang Inst. for Theoretical Physics

    2008-01-15

    We construct rigidly supersymmetric bulk-plus-boundary actions, both in x-space and in superspace. For each standard supersymmetric bulk action a minimal supersymmetric bulk-plus-boundary action follows from an extended F- or D-term formula. Additional separately supersymmetric boundary actions can be systematically constructed using co-dimension one multiplets (boundary superfields). We also discuss the orbit of boundary conditions which follow from the Euler-Lagrange variational principle. (orig.)

  2. Endodontic medicine: connections between apical periodontitis and systemic diseases.

    Science.gov (United States)

    Segura-Egea, J J; Martín-González, J; Castellanos-Cosano, L

    2015-10-01

    The prevalence of apical periodontitis (AP) in Europe has been reported to affect 61% of individuals and 14% of teeth, and increase with age. Likewise, the prevalence of root canal treatment (RCT) in Europe is estimated to be around 30-50% of individuals and 2-9% of teeth with radiographic evidence of chronic persistent AP in 30-65% of root filled teeth (RFT). AP is not only a local phenomenon and for some time the medical and dental scientific community have analysed the possible connection between apical periodontits and systemic health. Endodontic medicine has developed, with increasing numbers of reports describing the association between periapical inflammation and systemic diseases. The results of studies carried out both in animal models and humans are not conclusive, but suggest an association between endodontic variables, that is AP and RCT, and diabetes mellitus (DM), tobacco smoking, coronary heart disease and other systemic diseases. Several studies have reported a higher prevalence of periapical lesions, delayed periapical repair, greater size of osteolityc lesions, greater likelihood of asymptomatic infections and poorer prognosis for RFT in diabetic patients. On the other hand, recent studies have found that a poorer periapical status correlates with higher HbA1c levels and poor glycaemic control in type 2 diabetic patients. However, there is no scientific evidence supporting a causal effect of periapical inflammation on diabetes metabolic control. The possible association between smoking habits and endodontic infection has also been investigated, with controversial results. The aim of this paper was to review the literature on the association between endodontic variables and systemic health (especially DM and smoking habits). © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  3. A new technique for dynamic load distribution when two manipulators mutually lift a rigid object. Part 2, Derivation of entire system model and control architecture

    Energy Technology Data Exchange (ETDEWEB)

    Unseren, M.A.

    1994-04-01

    A rigid body model for the entire system which accounts for the load distribution scheme proposed in Part 1 as well as for the dynamics of the manipulators and the kinematic constraints is derived in the joint space. A technique is presented for expressing the object dynamics in terms of the joint variables of both manipulators which leads to a positive definite and symmetric inertia matrix. The model is then transformed to obtain reduced order equations of motion and a separate set of equations which govern the behavior of the internal contact forces. The control architecture is applied to the model which results in the explicit decoupling of the position and internal contact force-controlled degrees of freedom (DOF).

  4. Active vibration reduction of rigid rotor by kinematic excitation of bushes of journal bearings

    Directory of Open Access Journals (Sweden)

    J. Ondrouch

    2010-04-01

    Full Text Available Possibilities of active lateral vibration reduction of a symmetric, rigid rotor supported by journal bearings are given. They were obtained by computational modelling. Efficiency of the feedback P and PD controllers in the stable revolution interval was examined. The linearized rotor system model was used. The results of the theoretical analysis are assigned for a testing stand where the bearing bush motions are deactivated by piezoelectric actuators connected to the controllers.

  5. Novel deadbeat power control strategy for grid connected systems

    Directory of Open Access Journals (Sweden)

    Yousry Atia

    2015-09-01

    Full Text Available This paper introduces a novel approach for power control of three phase voltage source inverter (VSI in grid connected distribution generation system. In this approach, the control of active and reactive power is based on deadbeat control strategy. First, the difference between the reference and actual currents are introduced in different approach. Then current to power substitutions are carried out to obtain direct relationship between the required inverter voltage and instantaneous power errors. There is no need for coordinate transformation or PLL, where the required inverter voltage vector calculations carried out in α–β stationary reference frame. The proposed technique introduces two cross coupling components in the control function. Including these two components, the controller can achieve nearly zero steady-state tracking error of the controlled variables. To obtain fixed switching frequency operations, space vector modulation (SVM is used to synthesize the required inverter voltage vector and to generate the switching pulses for the VSI. The proposed strategy has the simplicity of the direct power control (DPC technique and doesn’t require any current control loops. The proposed strategy is experimentally implemented using fixed-point microcontroller. Simulation and experimental results are presented to confirm the superiority of the proposed strategy.

  6. Abnormally Malicious Autonomous Systems and their Internet Connectivity

    Energy Technology Data Exchange (ETDEWEB)

    Shue, Craig A [ORNL; Kalafut, Prof. Andrew [Grand Valley State University (GVSU), Michigan; Gupta, Prof. Minaxi [Indiana University

    2011-01-01

    While many attacks are distributed across botnets, investigators and network operators have recently targeted malicious networks through high profile autonomous system (AS) de-peerings and network shut-downs. In this paper, we explore whether some ASes indeed are safe havens for malicious activity. We look for ISPs and ASes that exhibit disproportionately high malicious behavior using ten popular blacklists, plus local spam data, and extensive DNS resolutions based on the contents of the blacklists. We find that some ASes have over 80% of their routable IP address space blacklisted. Yet others account for large fractions of blacklisted IP addresses. Several ASes regularly peer with ASes associated with significant malicious activity. We also find that malicious ASes as a whole differ from benign ones in other properties not obviously related to their malicious activities, such as more frequent connectivity changes with their BGP peers. Overall, we conclude that examining malicious activity at AS granularity can unearth networks with lax security or those that harbor cybercrime.

  7. Non-standard connections for non-autonomous systems

    International Nuclear Information System (INIS)

    Echeverria, A.; Munoz, M.C.; Roman, N.

    1995-01-01

    Dealing with the jet-bundle description of time-dependent classical mechanics, we prove that there are some elements, such as the Lagrangian energy and the construction of the Hamiltonian formalism, whose definition requires the previous choice of a connection. This is the same situation than in the jet-bundle description of first-order classical field theories although, in mechanics, this connection-dependence is usually hidden by the use of the natural connection given by the trivial bundle structure of the phase spaces in consideration. However, we also prove that this dependence is dynamically irrelevant. 7 refs

  8. A biomechanical testing system to determine micromotion between hip implant and femur accounting for deformation of the hip implant: Assessment of the influence of rigid body assumptions on micromotions measurements.

    Science.gov (United States)

    Leuridan, Steven; Goossens, Quentin; Roosen, Jorg; Pastrav, Leonard; Denis, Kathleen; Mulier, Michiel; Desmet, Wim; Vander Sloten, Jos

    2017-02-01

    Accurate pre-clinical evaluation of the initial stability of new cementless hip stems using in vitro micromotion measurements is an important step in the design process to assess the new stem's potential. Several measuring systems, linear variable displacement transducer-based and other, require assuming bone or implant to be rigid to obtain micromotion values or to calculate derived quantities such as relative implant tilting. An alternative linear variable displacement transducer-based measuring system not requiring a rigid body assumption was developed in this study. The system combined advantages of local unidirectional and frame-and-bracket micromotion measuring concepts. The influence and possible errors that would be made by adopting a rigid body assumption were quantified. Furthermore, as the system allowed emulating local unidirectional and frame-and-bracket systems, the influence of adopting rigid body assumptions were also analyzed for both concepts. Synthetic and embalmed bone models were tested in combination with primary and revision implants. Single-legged stance phase loading was applied to the implant - bone constructs. Adopting a rigid body assumption resulted in an overestimation of mediolateral micromotion of up to 49.7μm at more distal measuring locations. Maximal average relative rotational motion was overestimated by 0.12° around the anteroposterior axis. Frontal and sagittal tilting calculations based on a unidirectional measuring concept underestimated the true tilting by an order of magnitude. Non-rigid behavior is a factor that should not be dismissed in micromotion stability evaluations of primary and revision femoral implants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. System modelling and energy management for grid connected PV systems associated with storage

    OpenAIRE

    Riffonneau , Yann; DELAILLE , Arnaud; Barruel , Franck; Bacha , Seddik

    2008-01-01

    International audience; This paper presents the modelling and energy management of a grid connected PV system associatedwith storage. Within the economic, energetic and environmental context, objective of the system is to ensure loadssupply at the least cost by optimising the use of solar power. Therefore, due to the complicated operating patterns, anenergy management system which decides on energy flow for any moment is necessary. First, we present the systemstudied. Based on an AC bus typol...

  10. The two-body problem of a pseudo-rigid body and a rigid sphere

    DEFF Research Database (Denmark)

    Kristiansen, Kristian Uldall; Vereshchagin, M.; Gózdziewski, K.

    2012-01-01

    n this paper we consider the two-body problem of a spherical pseudo-rigid body and a rigid sphere. Due to the rotational and "re-labelling" symmetries, the system is shown to possess conservation of angular momentum and circulation. We follow a reduction procedure similar to that undertaken...... in the study of the two-body problem of a rigid body and a sphere so that the computed reduced non-canonical Hamiltonian takes a similar form. We then consider relative equilibria and show that the notions of locally central and planar equilibria coincide. Finally, we show that Riemann's theorem on pseudo......-rigid bodies has an extension to this system for planar relative equilibria....

  11. Quantum correction and ordering parameter for systems connected by a general point canonical transformation

    International Nuclear Information System (INIS)

    Yeon, Kyu Hwang; Hong, Suc Kyoung; Um, Chung In; George, Thomas F.

    2006-01-01

    With quantum operators corresponding to functions of the canonical variables, Schroedinger equations are constructed for systems corresponding to classical systems connected by a general point canonical transformation. Using the operator connecting quantum states between systems before and after the transformation, the quantum correction term and ordering parameter are obtained

  12. Fault Diagnosis Scheme for Nonlinear Stochastic Systems with Time-Varying Fault: Application to the Rigid Spacecraft Control

    Czech Academy of Sciences Publication Activity Database

    Nguyen, H.Q.; Čelikovský, Sergej

    2012-01-01

    Roč. 1, č. 3 (2012), s. 179-187 ISSN 2223-7038 R&D Projects: GA ČR(CZ) GAP103/12/1794 Institutional support: RVO:67985556 Keywords : Attitude control * adaptive fault estimation * LMI * PDF Subject RIV: BC - Control Systems Theory http://lib.physcon.ru/doc?id=02c925f7e4ab

  13. Conceptual design of a connected vehicle wrong-way driving detection and management system.

    Science.gov (United States)

    2016-04-01

    This report describes the tasks completed to develop a concept of operations, functional requirements, and : high-level system design for a Connected Vehicle (CV) Wrong-Way Driving (WWD) Detection and Management : System. This system was designed to ...

  14. Precast Concrete Beam-to-Column Connection System

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    Compared to conventional concrete constructions, precast concrete is a better option which is more cost-effective for production, transport, and erection when columns and beams can be fabricated independently. The BSF connection is a hidden beam and connection for gravity loads that eliminates the need for projecting column corbels. From a steel box cast into the concrete beam end, a sliding steel “knife” plate with a safety notch is cantilevered into a steel box that has been cast into the c...

  15. Connectivity of streams and wetlands to downstream waters: An integrated systems framework

    Science.gov (United States)

    Leibowitz, Scott G.; Wigington, Parker J.; Schoefield, Kate A.; Alexander, Laurie C.; Vanderhoof, Melanie; Golden, Heather E.

    2018-01-01

    Interest in connectivity has increased in the aquatic sciences, partly because of its relevance to the Clean Water Act. This paper has two objectives: (1) provide a framework to understand hydrological, chemical, and biological connectivity, focusing on how headwater streams and wetlands connect to and contribute to rivers; and (2) briefly review methods to quantify hydrological and chemical connectivity. Streams and wetlands affect river structure and function by altering material and biological fluxes to the river; this depends on two factors: (1) functions within streams and wetlands that affect material fluxes; and (2) connectivity (or isolation) from streams and wetlands to rivers that allows (or prevents) material transport between systems. Connectivity can be described in terms of frequency, magnitude, duration, timing, and rate of change. It results from physical characteristics of a system, e.g., climate, soils, geology, topography, and the spatial distribution of aquatic components. Biological connectivity is also affected by traits and behavior of the biota. Connectivity can be altered by human impacts, often in complex ways. Because of variability in these factors, connectivity is not constant but varies over time and space. Connectivity can be quantified with field‐based methods, modeling, and remote sensing. Further studies using these methods are needed to classify and quantify connectivity of aquatic ecosystems and to understand how impacts affect connectivity.

  16. Systemic Lupus Erythematosus and Systemic Autoimmune Connective Tissue Disorders behind Recurrent Diastolic Heart Failure

    Directory of Open Access Journals (Sweden)

    Luis Miguel Blasco Mata

    2012-01-01

    Full Text Available Diastolic heart failure (DHF remains unexplained in some patients with recurrent admissions after full investigation. A study was directed for screening SLE and systemic autoimmune connective tissue disorders in recurrent unexplained DHF patients admitted at a short-stay and intermediate care unit. It was found that systemic autoimmune conditions explained 11% from all of cases. Therapy also prevented new readmissions. Autoimmunity should be investigated in DHF.

  17. grid-connected photovoltaic system design for local government

    African Journals Online (AJOL)

    user

    wind power and has durability of more than twenty five years with a very minimal .... enhance energy yield of grid connected PV power plant by naturally catching .... cause it to operate at maximum power point irrespective of changing weather ...

  18. Systems biology, connectivity and the future of medicine

    NARCIS (Netherlands)

    Greef, J. van der

    2005-01-01

    The concept of systems-based strategies in medicine is emerging, with systems pathology guiding an understanding of the multidimensional aspects of disease system fingerprints and systems pharmacology providing insight into dynamic system responses upon (multiple) drug perturbations. Knowledge of

  19. Small-world topology of functional connectivity in randomly connected dynamical systems

    Czech Academy of Sciences Publication Activity Database

    Hlinka, Jaroslav; Hartman, David; Paluš, Milan

    2012-01-01

    Roč. 22, č. 3 (2012), art no 033107 ISSN 1054-1500 R&D Projects: GA ČR GCP103/11/J068 Institutional support: RVO:67985807 Keywords : graph theory * nonlinear dynamical systems * small-world networks Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 2.188, year: 2012

  20. A Simple Response Evaluation Method for Base-Isolation Building-Connection Hybrid Structural System under Long-Period and Long-Duration Ground Motion

    Directory of Open Access Journals (Sweden)

    Kohei Hayashi

    2018-02-01

    Full Text Available An innovative hybrid control building system of base-isolation and building-connection has been proposed in the previous study. This system has two advantages, (i to resist an impulsive earthquake input through the base-isolation system and (ii to withstand a long-duration earthquake input through the building-connection system. A simple response evaluation method without the need of non-linear time–history response analysis is proposed here for this hybrid building system under a long-period and long-duration ground motion. An analytical expression is derived in the plastic deformation of an elastic–perfectly plastic single-degree-of-freedom (SDOF model with viscous damping under the multi-impulse, which is the representative of long-period and long-duration ground motions. A transformation procedure of a base-isolation building-connection hybrid structural system into an SDOF model is proposed by introducing two steps, one is the reduction of the main base-isolated building to an SDOF system, and the other is the reduction of the connecting oil dampers supported on a free-wall to an oil damper with a newly introduced compensation factor on a rigid wall. Application of the analytical expression of the plastic deformation to the reduced SDOF model including the compensation factor on the connecting oil dampers enables the development of a simplified, but rather accurate response evaluation method. The time–history response analysis of the multi-degree-of-freedom model and the comparison with the proposed simplified formula make clear the accuracy and reliability of the proposed simplified response evaluation method.

  1. Analysis of the influences of grid-connected PV power system on distribution grids

    Directory of Open Access Journals (Sweden)

    Dumitru Popandron

    2013-12-01

    Full Text Available This paper presents the analysis of producing an electric power of 2.8 MW using a solar photovoltaic plant. The PV will be grid connected to the distribution network. The study is focused on the influences of connecting to the grid of a photovoltaic system, using modern software for analysis, modeling and simulation in power systems.

  2. Multiscale multiphysics and multidomain models—Flexibility and rigidity

    International Nuclear Information System (INIS)

    Xia, Kelin; Opron, Kristopher; Wei, Guo-Wei

    2013-01-01

    The emerging complexity of large macromolecules has led to challenges in their full scale theoretical description and computer simulation. Multiscale multiphysics and multidomain models have been introduced to reduce the number of degrees of freedom while maintaining modeling accuracy and achieving computational efficiency. A total energy functional is constructed to put energies for polar and nonpolar solvation, chemical potential, fluid flow, molecular mechanics, and elastic dynamics on an equal footing. The variational principle is utilized to derive coupled governing equations for the above mentioned multiphysical descriptions. Among these governing equations is the Poisson-Boltzmann equation which describes continuum electrostatics with atomic charges. The present work introduces the theory of continuum elasticity with atomic rigidity (CEWAR). The essence of CEWAR is to formulate the shear modulus as a continuous function of atomic rigidity. As a result, the dynamics complexity of a macromolecular system is separated from its static complexity so that the more time-consuming dynamics is handled with continuum elasticity theory, while the less time-consuming static analysis is pursued with atomic approaches. We propose a simple method, flexibility-rigidity index (FRI), to analyze macromolecular flexibility and rigidity in atomic detail. The construction of FRI relies on the fundamental assumption that protein functions, such as flexibility, rigidity, and energy, are entirely determined by the structure of the protein and its environment, although the structure is in turn determined by all the interactions. As such, the FRI measures the topological connectivity of protein atoms or residues and characterizes the geometric compactness of the protein structure. As a consequence, the FRI does not resort to the interaction Hamiltonian and bypasses matrix diagonalization, which underpins most other flexibility analysis methods. FRI's computational complexity is of O

  3. Grey matter connectivity within and between auditory, language and visual systems in prelingually deaf adolescents.

    Science.gov (United States)

    Li, Wenjing; Li, Jianhong; Wang, Zhenchang; Li, Yong; Liu, Zhaohui; Yan, Fei; Xian, Junfang; He, Huiguang

    2015-01-01

    Previous studies have shown brain reorganizations after early deprivation of auditory sensory. However, changes of grey matter connectivity have not been investigated in prelingually deaf adolescents yet. In the present study, we aimed to investigate changes of grey matter connectivity within and between auditory, language and visual systems in prelingually deaf adolescents. We recruited 16 prelingually deaf adolescents and 16 age-and gender-matched normal controls, and extracted the grey matter volume as the structural characteristic from 14 regions of interest involved in auditory, language or visual processing to investigate the changes of grey matter connectivity within and between auditory, language and visual systems. Sparse inverse covariance estimation (SICE) was utilized to construct grey matter connectivity between these brain regions. The results show that prelingually deaf adolescents present weaker grey matter connectivity within auditory and visual systems, and connectivity between language and visual systems declined. Notably, significantly increased brain connectivity was found between auditory and visual systems in prelingually deaf adolescents. Our results indicate "cross-modal" plasticity after deprivation of the auditory input in prelingually deaf adolescents, especially between auditory and visual systems. Besides, auditory deprivation and visual deficits might affect the connectivity pattern within language and visual systems in prelingually deaf adolescents.

  4. Geometric integrators for stochastic rigid body dynamics

    KAUST Repository

    Tretyakov, Mikhail

    2016-01-05

    Geometric integrators play an important role in simulating dynamical systems on long time intervals with high accuracy. We will illustrate geometric integration ideas within the stochastic context, mostly on examples of stochastic thermostats for rigid body dynamics. The talk will be mainly based on joint recent work with Rusland Davidchak and Tom Ouldridge.

  5. Geometric integrators for stochastic rigid body dynamics

    KAUST Repository

    Tretyakov, Mikhail

    2016-01-01

    Geometric integrators play an important role in simulating dynamical systems on long time intervals with high accuracy. We will illustrate geometric integration ideas within the stochastic context, mostly on examples of stochastic thermostats for rigid body dynamics. The talk will be mainly based on joint recent work with Rusland Davidchak and Tom Ouldridge.

  6. Torsional Rigidity of Minimal Submanifolds

    DEFF Research Database (Denmark)

    Markvorsen, Steen; Palmer, Vicente

    2006-01-01

    We prove explicit upper bounds for the torsional rigidity of extrinsic domains of minimal submanifolds $P^m$ in ambient Riemannian manifolds $N^n$ with a pole $p$. The upper bounds are given in terms of the torsional rigidities of corresponding Schwarz symmetrizations of the domains in warped...

  7. Cognitive Connected Vehicle Information System Design Requirement for Safety: Role of Bayesian Artificial Intelligence

    OpenAIRE

    Ata Khan

    2013-01-01

    Intelligent transportation systems (ITS) are gaining acceptance around the world and the connected vehicle component of ITS is recognized as a high priority research and development area in many technologically advanced countries. Connected vehicles are expected to have the capability of safe, efficient and eco-driving operations whether these are under human control or in the adaptive machine control mode of operations. The race is on to design the capability to operate in connected traffic ...

  8. Connected Lighting Systems Efficiency Study$-$ PoE Cable Energy Losses, Part 1

    Energy Technology Data Exchange (ETDEWEB)

    Tuenge, Jason [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kelly, Karsten [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Poplawski, Michael [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-11-30

    First report in a study of the efficiency of connected lighting systems. The report summarizes the results of an exploratory study investigating power losses in Ethernet cables used between PoE switches and luminaires in PoE connected lighting systems. Testing was conducted at the Pacific Northwest National Laboratory (PNNL) Connected Lighting Test Bed in September 2017. The results were analyzed to explore the impact of cable selection on PoE lighting system energy efficiency, as well as the effectiveness of guidelines recently introduced by the American National Standards Institute (ANSI) C137 Lighting Systems Committee.

  9. Increased functional connectivity between prefrontal cortex and reward system in pathological gambling.

    Directory of Open Access Journals (Sweden)

    Saskia Koehler

    Full Text Available Pathological gambling (PG shares clinical characteristics with substance-use disorders and is thus discussed as a behavioral addiction. Recent neuroimaging studies on PG report functional changes in prefrontal structures and the mesolimbic reward system. While an imbalance between these structures has been related to addictive behavior, whether their dysfunction in PG is reflected in the interaction between them remains unclear. We addressed this question using functional connectivity resting-state fMRI in male subjects with PG and controls. Seed-based functional connectivity was computed using two regions-of-interest, based on the results of a previous voxel-based morphometry study, located in the prefrontal cortex and the mesolimbic reward system (right middle frontal gyrus and right ventral striatum. PG patients demonstrated increased connectivity from the right middle frontal gyrus to the right striatum as compared to controls, which was also positively correlated with nonplanning aspect of impulsiveness, smoking and craving scores in the PG group. Moreover, PG patients demonstrated decreased connectivity from the right middle frontal gyrus to other prefrontal areas as compared to controls. The right ventral striatum demonstrated increased connectivity to the right superior and middle frontal gyrus and left cerebellum in PG patients as compared to controls. The increased connectivity to the cerebellum was positively correlated with smoking in the PG group. Our results provide further evidence for alterations in functional connectivity in PG with increased connectivity between prefrontal regions and the reward system, similar to connectivity changes reported in substance use disorder.

  10. Algebraic Methods for Counting Euclidean Embeddings of Rigid Graphs

    NARCIS (Netherlands)

    I.Z. Emiris; E.P. Tsigaridas; A. Varvitsiotis (Antonios); E.R. Gasner

    2009-01-01

    textabstract The study of (minimally) rigid graphs is motivated by numerous applications, mostly in robotics and bioinformatics. A major open problem concerns the number of embeddings of such graphs, up to rigid motions, in Euclidean space. We capture embeddability by polynomial systems

  11. Generalized Lotka—Volterra systems connected with simple Lie algebras

    International Nuclear Information System (INIS)

    Charalambides, Stelios A; Damianou, Pantelis A; Evripidou, Charalambos A

    2015-01-01

    We devise a new method for producing Hamiltonian systems by constructing the corresponding Lax pairs. This is achieved by considering a larger subset of the positive roots than the simple roots of the root system of a simple Lie algebra. We classify all subsets of the positive roots of the root system of type A n for which the corresponding Hamiltonian systems are transformed, via a simple change of variables, to Lotka-Volterra systems. For some special cases of subsets of the positive roots of the root system of type A n , we produce new integrable Hamiltonian systems. (paper)

  12. Generalized Lotka—Volterra systems connected with simple Lie algebras

    Science.gov (United States)

    Charalambides, Stelios A.; Damianou, Pantelis A.; Evripidou, Charalambos A.

    2015-06-01

    We devise a new method for producing Hamiltonian systems by constructing the corresponding Lax pairs. This is achieved by considering a larger subset of the positive roots than the simple roots of the root system of a simple Lie algebra. We classify all subsets of the positive roots of the root system of type An for which the corresponding Hamiltonian systems are transformed, via a simple change of variables, to Lotka-Volterra systems. For some special cases of subsets of the positive roots of the root system of type An, we produce new integrable Hamiltonian systems.

  13. Energy Storage Management in Grid Connected Solar Photovoltaic System

    OpenAIRE

    Vidhya M.E

    2015-01-01

    The penetration of renewable sources in the power system network in the power system has been increasing in the recent years. One of the solutions being proposed to improve the reliability and performance of these systems is to integrate energy storage device into the power system network. This paper discusses the modeling of photo voltaic and status of the storage device such as lead acid battery for better energy management in the system. The energy management for the grid conne...

  14. Motion of a Rigid Body Supported at One Point by a Rotating Arm

    Directory of Open Access Journals (Sweden)

    Jeffrey D. Stoen

    1993-01-01

    Full Text Available This article details a scheme for evaluating the stability of motions of a system consisting of a rigid body connected at one point to a rotating arm. The nonlinear equations of motion for the system are formulated, and a method for finding exact solutions representing motions that resemble a state of rest is presented. The equations are then linearized and roots of the eigensystem are classified and used to construct stability diagrams that facilitate the assessment of effects of varying the body's mass properties and system geometry, changing the position of the attachment joint, and adding energy dissipation in the joint.

  15. Photovoltaic system with improved AC connections and method of making same

    Energy Technology Data Exchange (ETDEWEB)

    Cioffi, Philip Michael; Todorovic, Maja Harfman; Herzog, Michael Scott; Korman, Charles Steven; Doherty, Donald M.; Johnson, Neil Anthony

    2018-02-13

    An alternating current (AC) harness for a photovoltaic (PV) system includes a wire assembly having a first end and a second end, the wire assembly having a plurality of lead wires, and at least one AC connection module positioned at a location along a length of the wire assembly between the first end and the second end. Further, the at least one AC connection module includes a first connection terminal electrically coupled to the plurality of lead wires of the wire assembly and constructed to electrically couple the wire assembly with an output of a first PV module of the PV system. The at least one AC connection module also includes a second connection terminal electrically coupled to the plurality of lead wires of the wire assembly and constructed to electrically couple the wire assembly with an output of a second PV module of the PV system.

  16. A method for measuring the inertia properties of rigid bodies

    Science.gov (United States)

    Gobbi, M.; Mastinu, G.; Previati, G.

    2011-01-01

    A method for the measurement of the inertia properties of rigid bodies is presented. Given a rigid body and its mass, the method allows to measure (identify) the centre of gravity location and the inertia tensor during a single test. The proposed technique is based on the analysis of the free motion of a multi-cable pendulum to which the body under consideration is connected. The motion of the pendulum and the forces acting on the system are recorded and the inertia properties are identified by means of a proper mathematical procedure based on a least square estimation. After the body is positioned on the test rig, the full identification procedure takes less than 10 min. The natural frequencies of the pendulum and the accelerations involved are quite low, making this method suitable for many practical applications. In this paper, the proposed method is described and two test rigs are presented: the first is developed for bodies up to 3500 kg and the second for bodies up to 400 kg. A validation of the measurement method is performed with satisfactory results. The test rig holds a third part quality certificate according to an ISO 9001 standard and could be scaled up to measure the inertia properties of huge bodies, such as trucks, airplanes or even ships.

  17. Optical Fiber Connection Navigation System Using Visible Light Communication in Central Office with Economic Evaluation

    Science.gov (United States)

    Waki, Masaki; Uruno, Shigenori; Ohashi, Hiroyuki; Manabe, Tetsuya; Azuma, Yuji

    We propose an optical fiber connection navigation system that uses visible light communication for an integrated distribution module in a central office. The system realizes an accurate database, requires less skilled work to operate and eliminates human error. This system can achieve a working time reduction of up to 88.0% compared with the conventional work without human error for the connection/removal of optical fiber cords, and is economical as regards installation and operation.

  18. Parallel O(log n) algorithms for open- and closed-chain rigid multibody systems based on a new mass matrix factorization technique

    Science.gov (United States)

    Fijany, Amir

    1993-01-01

    In this paper, parallel O(log n) algorithms for computation of rigid multibody dynamics are developed. These parallel algorithms are derived by parallelization of new O(n) algorithms for the problem. The underlying feature of these O(n) algorithms is a drastically different strategy for decomposition of interbody force which leads to a new factorization of the mass matrix (M). Specifically, it is shown that a factorization of the inverse of the mass matrix in the form of the Schur Complement is derived as M(exp -1) = C - B(exp *)A(exp -1)B, wherein matrices C, A, and B are block tridiagonal matrices. The new O(n) algorithm is then derived as a recursive implementation of this factorization of M(exp -1). For the closed-chain systems, similar factorizations and O(n) algorithms for computation of Operational Space Mass Matrix lambda and its inverse lambda(exp -1) are also derived. It is shown that these O(n) algorithms are strictly parallel, that is, they are less efficient than other algorithms for serial computation of the problem. But, to our knowledge, they are the only known algorithms that can be parallelized and that lead to both time- and processor-optimal parallel algorithms for the problem, i.e., parallel O(log n) algorithms with O(n) processors. The developed parallel algorithms, in addition to their theoretical significance, are also practical from an implementation point of view due to their simple architectural requirements.

  19. Connecting the Dots: Data Use in Afterschool Systems. Research Brief

    Science.gov (United States)

    Spielberger, Julie; Axelrod, Jennifer; Dasgupta, Denali; Cerven, Christine; Spain, Angeline; Kohm, Amelia; Mader, Nicholas

    2016-01-01

    To support the effectiveness of afterschool programs in fostering skills youth need to succeed in school and life, a growing number of cities have invested in afterschool systems to coordinate disparate programs and funding streams. A primary function of most afterschool systems is to develop and maintain a data system to collect, analyze, and…

  20. Connecting the Dots: Data Use in Afterschool Systems

    Science.gov (United States)

    Spielberger, Julie; Axelrod, Jennifer; Dasgupta, Denali; Cerven, Christine; Spain, Angeline; Kohm, Amelia; Mader, Nicholas

    2016-01-01

    To support the effectiveness of afterschool programs in fostering skills youth need to succeed in school and life, a growing number of cities have invested in afterschool systems to coordinate disparate programs and funding streams. A primary function of most afterschool systems is to develop and maintain a data system to collect, analyze, and…

  1. Research on comprehensive decision-making of PV power station connecting system

    Science.gov (United States)

    Zhou, Erxiong; Xin, Chaoshan; Ma, Botao; Cheng, Kai

    2018-04-01

    In allusion to the incomplete indexes system and not making decision on the subjectivity and objectivity of PV power station connecting system, based on the combination of improved Analytic Hierarchy Process (AHP), Criteria Importance Through Intercriteria Correlation (CRITIC) as well as grey correlation degree analysis (GCDA) is comprehensively proposed to select the appropriate system connecting scheme of PV power station. Firstly, indexes of PV power station connecting system are divided the recursion order hierarchy and calculated subjective weight by the improved AHP. Then, CRITIC is adopted to determine the objective weight of each index through the comparison intensity and conflict between indexes. The last the improved GCDA is applied to screen the optimal scheme, so as to, from the subjective and objective angle, select the connecting system. Comprehensive decision of Xinjiang PV power station is conducted and reasonable analysis results are attained. The research results might provide scientific basis for investment decision.

  2. Use of a mobile terrestrial laser system to quantify the impact of rigid coastal protective structures on sandy beaches, Quebec, Canada

    Science.gov (United States)

    Van-Wierts, S.; Bernatchez, P.

    2012-04-01

    Coastal erosion is an important issue within the St-Lawrence estuary and gulf, especially in zones of unconsolidated material. Wide beaches are important coastal environments; they act as a buffer against breaking waves by absorbing and dissipating their energy, thus reducing the rate of coastal erosion. They also offer protection to humans and nearby ecosystems, providing habitat for plants, animals and lifeforms such as algae and microfauna. Conventional methods, such as aerial photograph analysis, fail to adequately quantify the morphosedimentary behavior of beaches at the scale of a hydrosedimentary cells. The lack of reliable and quantitative data leads to considerable errors of overestimation and underestimation of sediment budgets. To address these gaps and to minimize acquisition costs posed by airborne LiDAR survey, a mobile terrestrial LiDAR has been set up to acquire topographic data of the coastal zone. The acquisition system includes a LiDAR sensor, a high precision navigation system (GPS-INS) and a video camera. Comparison of LiDAR data with 1050 DGPS control points shows a vertical mean absolute error of 0.1 m in beach areas. The extracted data is used to calculate sediment volumes, widths, slopes, and a sediment budget index. A high accuracy coastal characterization is achieved through the integration of laser data and video. The main objective of this first project using this system is to quantify the impact of rigid coastal protective structures on sediment budget and beach morphology. Results show that the average sediment volume of beaches located before a rock armour barrier (12 m3/m) were three times narrower than for natural beaches (35,5 m3/m). Natural beaches were also found to have twice the width (25.4 m) of the beaches bordering inhabited areas (12.7 m). The development of sediment budget index for beach areas is an excellent proxy to quickly identify deficit areas and therefore the coastal segments most at risk of erosion. The obtained

  3. Mirror Neuron System and Mentalizing System connect during online social interaction.

    Science.gov (United States)

    Sperduti, Marco; Guionnet, Sophie; Fossati, Philippe; Nadel, Jacqueline

    2014-08-01

    Two sets of brain areas are repeatedly reported in neuroimaging studies on social cognition: the Mirror Neuron System and the Mentalizing System. The Mirror System is involved in goal understanding and has been associated with several emotional and cognitive functions central to social interaction, ranging from empathy to gestural communication and imitation. The Mentalizing System is recruited in tasks requiring cognitive processes such as self-reference and understanding of other's intentions. Although theoretical accounts for an interaction between the two systems have been proposed, little is known about their synergy during social exchanges. In order to explore this question, we have recorded brain activity by means of functional MRI during live social exchanges based on reciprocal imitation of hand gestures. Here, we investigate, using the method of psychophysiological interaction, the changes in functional connectivity of the Mirror System due to the conditions of interest (being imitated, imitating) compared with passive observation of hand gestures. We report a strong coupling between the Mirror System and the Mentalizing System during the imitative exchanges. Our findings suggest a complementary role of the two networks during social encounters. The Mirror System would engage in the preparation of own actions and the simulation of other's actions, while the Mentalizing System would engage in the anticipation of the other's intention and thus would participate to the co-regulation of reciprocal actions. Beyond a specific effect of imitation, the design used offers the opportunity to tackle the role of role-switching in an interpersonal account of social cognition.

  4. Cracking of open traffic rigid pavement

    Directory of Open Access Journals (Sweden)

    Niken Chatarina

    2017-01-01

    Full Text Available The research is done by observing the growth of real structure cracking in Natar, Lampung, Indonesia compared to C. Niken’s et al research and literature study. The rigid pavement was done with open traffic system. There are two main crack types on Natar rigid pavement: cracks cross the road, and cracks spreads on rigid pavement surface. The observation of cracks was analyzed by analyzing material, casting, curing, loading and shrinkage mechanism. The relationship between these analysis and shrinkage mechanism was studied in concrete micro structure. Open traffic make hydration process occur under vibration; therefore, fresh concrete was compressed and tensioned alternately since beginning. High temperature together with compression, cement dissociation, the growth of Ca2+ at very early age leads abnormal swelling. No prevention from outside water movement leads hydration process occur with limited water which caused spreads fine cracks. Limited water improves shrinkage and plastic phase becomes shorter; therefore, rigid pavement can’t accommodate the abnormal swelling and shrinking alternately and creates the spread of cracks. Discontinuing casting the concrete makes both mix under different condition, the first is shrink and the second is swell and creates weak line on the border; so, the cracks appear as cracks across the road.

  5. High-Efficiency Photovoltaic System Using Partially-Connected DC-DC Converter

    Science.gov (United States)

    Uno, Masatoshi; Kukita, Akio; Tanaka, Koji

    Power conversion electronics for photovoltaic (PV) systems are desired to operate as efficiently as possible to exploit the power generated by PV modules. This paper proposes a novel PV system in which a dc-dc converter is partially connected to series-connected PV modules. The proposed system achieves high power-conversion efficiency by reducing the passing power and input/output voltages of the converter. The theoretical operating principle was experimentally validated. Resultant efficiency performances of the proposed and conventional systems demonstrated that the proposed system was more efficient in terms of power conversion though the identical converter was used for the both systems.

  6. The Impact of Connecting Distributed Generation to the Distribution System

    Directory of Open Access Journals (Sweden)

    E. V. Mgaya

    2007-01-01

    Full Text Available This paper deals with the general problem of utilizing of renewable energy sources to generate electric energy. Recent advances in renewable energy power generation technologies, e.g., wind and photovoltaic (PV technologies, have led to increased interest in the application of these generation devices as distributed generation (DG units. This paper presents the results of an investigation into possible improvements in the system voltage profile and reduction of system losses when adding wind power DG (wind-DG to a distribution system. Simulation results are given for a case study, and these show that properly sized wind DGs, placed at carefully selected sites near key distribution substations, could be very effective in improving the distribution system voltage profile and reducing power losses, and hence could  improve the effective capacity of the system

  7. A conceptual connectivity framework for understanding geomorphic change in human-impacted fluvial systems

    Science.gov (United States)

    Pöppl, Ronald; Keesstra, Saskia; Maroulis, Jerry

    2017-04-01

    Human-induced landscape change is difficult to predict due to the complexity inherent in both geomorphic and social systems as well as due to emerging coupling relationships between them. To better understand system complexity and system response to change, connectivity has become an important research paradigm within various disciplines including geomorphology, hydrology and ecology. With the proposed conceptual connectivity framework on geomorphic change in human-impacted fluvial systems a cautionary note is flagged regarding the need (i) to include and to systematically conceptualise the role of different types of human agency in altering connectivity relationships in geomorphic systems and (ii) to integrate notions of human-environment interactions to connectivity concepts in geomorphology to better explain causes and trajectories of landscape change. Underpinned by case study examples, the presented conceptual framework is able to explain how geomorphic response of fluvial systems to human disturbance is determined by system-specific boundary conditions (incl. system history, related legacy effects and lag times), vegetation dynamics and human-induced functional relationships (i.e. feedback mechanisms) between the different spatial dimensions of connectivity. It is further demonstrated how changes in social systems can trigger a process-response feedback loop between social and geomorphic systems that further governs the trajectory of landscape change in coupled human-geomorphic systems.

  8. Development and Testing of a Prototype Connected Vehicle Wrong-Way Driving Detection and Management System

    Science.gov (United States)

    2018-02-01

    The primary objective of Phase II was to develop a prototype connected vehicle wrong-way driving detection and management system at the Texas A&M University Respect, Excellence, Leadership, Loyalty, Integrity, Selfless Service (RELLIS) campus. The pu...

  9. On the Connectivity of Wireless Network Systems and an Application in Teacher-Student Interactive Platforms

    Directory of Open Access Journals (Sweden)

    Xun Ge

    2014-01-01

    Full Text Available A wireless network system is a pair (U;B, where B is a family of some base stations and U is a set of their users. To investigate the connectivity of wireless network systems, this paper takes covering approximation spaces as mathematical models of wireless network systems. With the help of covering approximation operators, this paper characterizes the connectivity of covering approximation spaces by their definable subsets. Furthermore, it is obtained that a wireless network system is connected if and only if the relevant covering approximation space has no nonempty definable proper subset. As an application of this result, the connectivity of a teacher-student interactive platform is discussed, which is established in the School of Mathematical Sciences of Soochow University. This application further demonstrates the usefulness of rough set theory in pedagogy and makes it possible to research education by logical methods and mathematical methods.

  10. Flexible Mode Control of Grid Connected Wind Energy Conversion System Using Wavelet

    OpenAIRE

    Jain, Bhavna; Singh, Sameer; Jain, Shailendra; Nema, R. K.

    2015-01-01

    Small wind turbine systems offer services to critical loads during grid faults and also connected back to grid in normal condition. The connection of a wind energy conversion system to the grid requires a robust phase locked loop (PLL) and continuous monitoring of the grid conditions such as overvoltage, undervoltage, overfrequency, underfrequency, and grid outages. This paper describes a flexible control operation to operate a small wind turbine in both stand-alone mode via planned islanding...

  11. Sectional pipeline bundles. Design, fabrication and testing of a subsea pipeline connection system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-08-01

    The tests of the prototype system indicated that the system is applicable for connecting pipeline bundle sections. The overall performance of the system is therefore concluded to be satisfactory. Some modifications are required though, for improving the reliability of the system to the level required for offshore North Sea application. The tests showed that connection of the pipeline bundle sections can be performed for alignment tolerances larger than those expected during a typical subsea installation. Pull-in of bundle end sections can be performed with pull-in wires deployed from surface. The offshore tests showed that handling of wires must be done with great care to avoid possibility for wire entanglement, especially if a fully diverless system is to be used. The flowline connection tool was found to be suitable for final alignment of the individual spool ends. It was demonstrated that face to face contact between the hub faces in the connector was obtained after tie-in. Pressure tests showed that the connector could be sealed by the tie-in force applied by the connection tool tie-in system. However, the standard connector clamp which was used, was found to be insuficient for maintaining the connector effectively sealed after removal of the pull-in force applied by the connection tool. Based on the results proposals for improvements of the system are included. Improvements are applicable to the current system for connection of bundle sections or for tie-in operations, relating to conventional pipelines. The improvements also includes a strong connection clamp suitable for subsea use. The connection clamp will replace the standard clamp devise used in this project. (au) EFP-96. 41 refs.

  12. A Sensorless Power Reserve Control Strategy for Two-Stage Grid-Connected PV Systems

    OpenAIRE

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2017-01-01

    Due to the still increasing penetration of grid-connected Photovoltaic (PV) systems, advanced active power control functionalities have been introduced in grid regulations. A power reserve control, where namely the active power from the PV panels is reserved during operation, is required for grid support. In this paper, a cost-effective solution to realize the power reserve for two-stage grid-connected PV systems is proposed. The proposed solution routinely employs a Maximum Power Point Track...

  13. Level of Service Considerations in Connection with Capacity Adjustment by ITS Systems

    DEFF Research Database (Denmark)

    Jensen, Peder; Andersen, Claus Lund

    1998-01-01

    The paper explores the level of service definition in connection with urban traffic and ITS systems. In addition a new definition is suggested to account for problems encountered with the traditional definition.......The paper explores the level of service definition in connection with urban traffic and ITS systems. In addition a new definition is suggested to account for problems encountered with the traditional definition....

  14. Rigid body formulation in a finite element context with contact interaction

    Science.gov (United States)

    Refachinho de Campos, Paulo R.; Gay Neto, Alfredo

    2018-03-01

    The present work proposes a formulation to employ rigid bodies together with flexible bodies in the context of a nonlinear finite element solver, with contact interactions. Inertial contributions due to distribution of mass of a rigid body are fully developed, considering a general pole position associated with a single node, representing a rigid body element. Additionally, a mechanical constraint is proposed to connect a rigid region composed by several nodes, which is useful for linking rigid/flexible bodies in a finite element environment. Rodrigues rotation parameters are used to describe finite rotations, by an updated Lagrangian description. In addition, the contact formulation entitled master-surface to master-surface is employed in conjunction with the rigid body element and flexible bodies, aiming to consider their interaction in a rigid-flexible multibody environment. New surface parameterizations are presented to establish contact pairs, permitting pointwise interaction in a frictional scenario. Numerical examples are provided to show robustness and applicability of the methods.

  15. CSP channels for CAN-bus connected embedded control systems

    NARCIS (Netherlands)

    Orlic, B.; Broenink, Johannes F.; Schweizer, M.

    2002-01-01

    Closed loop control system typically contains multitude of sensors and actuators operated simultaneously. So they are parallel and distributed in its essence. But when mapping this parallelism to software, lot of obstacles concerning multithreading communication and synchronization issues arise. To

  16. Connecting remote systems for demonstration of automation technologies

    Science.gov (United States)

    Brown, R. M.; Yee, R.

    1988-01-01

    An initial estimate of the communications requirements of the Systems Autonomy Demonstration Project (SADP) development and demonstration environments is presented. A proposed network paradigm is developed, and options for network topologies are explored.

  17. Optimum Design Of Grid Connected Photovoltaic System Using Concentrators

    Directory of Open Access Journals (Sweden)

    Eng. Mohammed Fawzy

    2015-08-01

    Full Text Available Abstract Due to the increasing demand of electrical energy in Egypt and also in many neighboring countries around the world the main problem facing electrical energy production using classical methods such steam power stations is the depletion of fossil fuels. The gap between the electrical energy demand and the continuous increase on the fossil fuel cost make the problem of electricity generation more sophisticated. With the continuous decrease of the photovoltaic PV technologies cost it doesnt make sense neglecting the importance of electricity production using solar photovoltaic PV especially that the annual average daily energy received is about 6 kamp12310whmamp123112day in Cairo Egypt 30N.In this work a detailed simulation model including photovoltaic PV module characteristics and climatic conditions of Cairo Egypt is developed. The model compares fixed PV systems electrical energy output with photovoltaic PV system using concentrators and double axis tracker systems. The comparison includes the energy generated area required as well as the cost per kwh generated. The optimality criterion is the cost per kwh generated. The system that gives the minimum cost per kwh is the optimum system. To verify the developed model the simulation results of fixed PV modules and CPV using tracking system obtained by the model are compared with practical measurements of 40KW peak station erected in Cairo Egypt 30N.Very good agreement between measured values and results obtained from detailed simulation model. For fixed PV system the detailed economic analysis showed that it gives minimum cost perkwh generated Comparisons among these systems are presented. For Cairo results showed that a cost of about 6 to 9 US centskwh is attainable.

  18. Design issues for grid-connected photovoltaic systems

    Science.gov (United States)

    Ropp, Michael Eugene

    1998-08-01

    Photovoltaics (PV) is the direct conversion of sunlight to electrical energy. In areas without centralized utility grids, the benefits of PV easily overshadow the present shortcomings of the technology. However, in locations with centralized utility systems, significant technical challenges remain before utility-interactive PV (UIPV) systems can be integrated into the mix of electricity sources. One challenge is that the needed computer design tools for optimal design of PV systems with curved PV arrays are not available, and even those that are available do not facilitate monitoring of the system once it is built. Another arises from the issue of islanding. Islanding occurs when a UIPV system continues to energize a section of a utility system after that section has been isolated from the utility voltage source. Islanding, which is potentially dangerous to both personnel and equipment, is difficult to prevent completely. The work contained within this thesis targets both of these technical challenges. In Task 1, a method for modeling a PV system with a curved PV array using only existing computer software is developed. This methodology also facilitates comparison of measured and modeled data for use in system monitoring. The procedure is applied to the Georgia Tech Aquatic Center (GTAC) FV system. In the work contained under Task 2, islanding prevention is considered. The existing state-of-the- art is thoroughly reviewed. In Subtask 2.1, an analysis is performed which suggests that standard protective relays are in fact insufficient to guarantee protection against islanding. In Subtask 2.2. several existing islanding prevention methods are compared in a novel way. The superiority of this new comparison over those used previously is demonstrated. A new islanding prevention method is the subject under Subtask 2.3. It is shown that it does not compare favorably with other existing techniques. However, in Subtask 2.4, a novel method for dramatically improving this new

  19. The Mast Cell, Contact, and Coagulation System Connection in Anaphylaxis

    Directory of Open Access Journals (Sweden)

    Mar Guilarte

    2017-07-01

    Full Text Available Anaphylaxis is the most severe form of allergic reaction, resulting from the effect of mediators and chemotactic substances released by activated cells. Mast cells and basophils are considered key players in IgE-mediated human anaphylaxis. Beyond IgE-mediated activation of mast cells/basophils, further mechanisms are involved in the occurrence of anaphylaxis. New insights into the potential relevance of pathways other than mast cell and basophil degranulation have been unraveled, such as the activation of the contact and the coagulation systems. Mast cell heparin released upon activation provides negatively charged surfaces for factor XII (FXII binding and auto-activation. Activated FXII, the initiating serine protease in both the contact and the intrinsic coagulation system, activates factor XI and prekallikrein, respectively. FXII-mediated bradykinin (BK formation has been proven in the human plasma of anaphylactic patients as well as in experimental models of anaphylaxis. Moreover, the severity of anaphylaxis is correlated with the increase in plasma heparin, BK formation and the intensity of contact system activation. FXII also activates plasminogen in the fibrinolysis system. Mast cell tryptase has been shown to participate in fibrinolysis through plasmin activation and by facilitating the degradation of fibrinogen. Some usual clinical manifestations in anaphylaxis, such as angioedema or hypotension, or other less common, such as metrorrhagia, may be explained by the direct effect of the activation of the coagulation and contact system driven by mast cell mediators.

  20. Any time, anywhere : communications system keeps employees connected

    Energy Technology Data Exchange (ETDEWEB)

    Louie, J.

    2007-07-15

    Cisco Systems Canada is a leading computer networking company that has developed a business solution for the oil and gas sector that allows employees to communicate more effectively. Cisco Unified Communications provides a set of applications or services that can ride on top an existing data network. The network allows telephone conferencing through a centrally located internal application, saving companies the cost of using a conferencing service. Cisco Unified Meeting place allows workers at different locations to discuss, review and edit documents in real time. Other applications can be added and made available to everyone. Pengrowth Energy Trust, which implemented the Cisco system a few years ago, claims it is much faster and more convenient than the previous system. Pengrowth has benefited from the its tie-in with e-mail server Microsoft Exchange. Users can listen to voice mails on their computers and also have the option of listening to their e-mails when they call into the office. The system provides a very well tracked record and also allows four-digit dialing throughout most of the company's multiple locations, thereby eliminating costly long distance charges. Pengrowth is now considering implementing other new products from Cisco, such as the Unified Mobility Manager which links cell phones and desk phones. It was concluded that Cisco systems offer the advantages of flexibility, mobility and cost reduction. 1 fig.

  1. Reliability/Cost Evaluation on Power System connected with Wind Power for the Reserve Estimation

    DEFF Research Database (Denmark)

    Lee, Go-Eun; Cha, Seung-Tae; Shin, Je-Seok

    2012-01-01

    Wind power is ideally a renewable energy with no fuel cost, but has a risk to reduce reliability of the whole system because of uncertainty of the output. If the reserve of the system is increased, the reliability of the system may be improved. However, the cost would be increased. Therefore...... the reserve needs to be estimated considering the trade-off between reliability and economic aspects. This paper suggests a methodology to estimate the appropriate reserve, when wind power is connected to the power system. As a case study, when wind power is connected to power system of Korea, the effects...

  2. Grid connection of active stall wind farms using a VSC based DC transmission system

    DEFF Research Database (Denmark)

    Iov, F.; Sørensen, Poul Ejnar; Hansen, A.D.

    2005-01-01

    Currently, there is an increasing trend to connect large MW wind farms to the transmission system. Requirements that focus on the influence of the farms on the grid stability and power quality, and on the control capabilities of wind farms have already been established. The main trends of modern...... wind turbines/farms are clearly the variable speed operation and a grid connection through a power electronic interface, especially using doubly fed induction generators. Using power electronics the control capabilities of these wind turbines/farms are extended and thus the grid requirements...... are fulfilled. However, the traditional squirrel-cage generators based wind turbines/wind farms directly connected to the grid have less control capabilities. These wind turbines/farms cannot regulate their production and contribute to power system stability. A DC transmission system for connection...

  3. EMISSIONS REDUCTION DATA FOR GRID-CONNECTED PHOTOVOLTAIC POWER SYSTEMS

    Science.gov (United States)

    This study measured the pollutant emission reduction potential of 29 photovoltaic (PV) systems installed on residential and commercial building rooftops across the U.S. from 1993 through 1997. The U.S. Environmental Protection Agency (EPA) and 21 electric power companies sponsor...

  4. A single phase photovoltaic inverter control for grid connected system

    Indian Academy of Sciences (India)

    operation the PV inverter operates in voltage-controlled mode to maintain a constant amplitude and frequency of the voltage ..... 10W i.e. less than 8% of the maximum power, a step size of k2 is ...... ply/demand side management system.

  5. Research on Connection and Function Reliability of the Oil&Gas Pipeline System

    Directory of Open Access Journals (Sweden)

    Xu Bo

    2017-01-01

    Full Text Available Pipeline transportation is the optimal way for energy delivery in terms of safety, efficiency and environmental protection. Because of the complexity of pipeline external system including geological hazards, social and cultural influence, it is a great challenge to operate the pipeline safely and reliable. Therefore, the pipeline reliability becomes an important issue. Based on the classical reliability theory, the analysis of pipeline system is carried out, then the reliability model of the pipeline system is built, and the calculation is addressed thereafter. Further the connection and function reliability model is applied to a practical active pipeline system, with the use of the proposed methodology of the pipeline system; the connection reliability and function reliability are obtained. This paper firstly presented to considerate the connection and function reliability separately and obtain significant contribution to establish the mathematical reliability model of pipeline system, hence provide fundamental groundwork for the pipeline reliability research in the future.

  6. Wind power integration connection and system operational aspects

    CERN Document Server

    Fox, Brendan

    2014-01-01

    Wind Power Integration provides a wide-ranging discussion on all major aspects of wind power integration into electricity supply systems. This second edition has been fully revised and updated to take account of the significant growth in wind power deployment in the past few years. New discussions have been added to describe developments in wind turbine generator technology and control, the network integration of wind power, innovative ways to integrate wind power when its generation potential exceeds 50% of demand, case studies on how forecasting errors have affected system operation, and an update on how the wind energy sector has fared in the marketplace. Topics covered include: the development of wind power technology and its world-wide deployment; wind power technology and the interaction of various wind turbine generator types with the utility network; and wind power forecasting and the challenges faced by wind energy in modern electricity markets.

  7. Mobile Connectivity and Security Issues for Cloud Informatic Systems

    OpenAIRE

    Cosmin Cătălin Olteanu

    2015-01-01

    The main purpose of the paper is to illustrate the importance of new software tools that can be used with mobile devices to make them more secure for the use of day to day business software. Many companies are using mobile applications to access some components to ERP’s or CRM’s remotely. Even the new come, cloud Informatic Systems are using more remote devices than ever. This is why we need to secure somehow these mobile applications.

  8. Mobile Connectivity and Security Issues for Cloud Informatic Systems

    Directory of Open Access Journals (Sweden)

    Cosmin Cătălin Olteanu

    2015-05-01

    Full Text Available The main purpose of the paper is to illustrate the importance of new software tools that can be used with mobile devices to make them more secure for the use of day to day business software. Many companies are using mobile applications to access some components to ERP’s or CRM’s remotely. Even the new come, cloud Informatic Systems are using more remote devices than ever. This is why we need to secure somehow these mobile applications.

  9. Topological orders in rigid states

    International Nuclear Information System (INIS)

    Wen, X.G.

    1990-01-01

    The authors study a new kind of ordering topological order in rigid states (the states with no local gapless excitations). This paper concentrates on characterization of the different topological orders. As an example the authors discuss in detail chiral spin states of 2+1 dimensional spin systems. Chiral spin states are described by the topological Chern-Simons theories in the continuum limit. The authors show that the topological orders can be characterized by a non-Abelian gauge structure over the moduli space which parametrizes a family of the model Hamiltonians supporting topologically ordered ground states. In 2 + 1 dimensions, the non-Abelian gauge structure determines possible fractional statistics of the quasi-particle excitations over the topologically ordered ground states. The dynamics of the low lying global excitations is shown to be independent of random spatial dependent perturbations. The ground state degeneracy and the non-Abelian gauge structures discussed in this paper are very robust, even against those perturbations that break translation symmetry. The authors also discuss the symmetry properties of the degenerate ground states of chiral spin states. The authors find that some degenerate ground states of chiral spin states on torus carry non-trivial quantum numbers of the 90 degrees rotation

  10. Quality and Innovation: Redesigning a Coordinated and Connected Health System.

    Science.gov (United States)

    Vaughan, Peter W

    2017-01-01

    Nova Scotia's consolidated health system was launched on April 1, 2015. This new approach to organizing health administration and services in the province arose out of necessity. When planning began, Nova Scotia was spending 41% of its annual budget on health services. In comparison to other provinces and territories, our per capita health-related spending was among the highest in the country, we had one of Canada's oldest populations and we had some of the worst health outcomes. Clearly, we could not continue to do the same things and expect different results. Both the life sciences and technology are changing at breakneck speed, while design of healthcare delivery has barely moved beyond a mid-twentieth century paternalistic provider-centric model. Nova Scotia's transformation journey was facilitated by a major policy effort 20 years earlier that had integrated emergency health services across the province. Our aim was to build on that foundation by integrating administration in order to build primary care networks with enhanced regional specialty services, with tertiary services located in Halifax. The goal of health system innovation in Nova Scotia was - and is - based firmly on the dimensions of quality: safe care that avoids harming patients; effective care that is based on levels of evidence to achieve scalability; access to care that is focused on individuals; efficient care that reduces waste, time, energy and supplies; and equitable care that ensures a system is in place that mitigates differences in geography and social economic status. The author offers a sketch of the principal initiatives, challenges, considerations, approaches and lessons involved in this multi-factorial, multi-stakeholder innovation process.

  11. Testing space weather connections in the solar system

    Science.gov (United States)

    Grison, B.; Souček, J.; Krupař, V.; Píša, D.; Santolík, O.; Taubenschuss, U.; Němec, F.

    2017-09-01

    This study aims at testing and validating tools for prediction of the impact of solar events in the vicinity of inner and outer solar system planets using in-situ spacecraft data (primarily MESSENGER, STEREO and ACE, but also VEX and Cassini), remote Jovian observations (Hubble telescope, Nançay decametric array), existing catalogues (HELCATS and Tao et al. (2005)) and the tested propagating models (the ICME radial propagation tool of the CDPP and the 1-D MHD code propagation model presented in Tao et al. (2005)).

  12. Research on simulated devices for Solar photovoltaic grid-connected generation system

    Directory of Open Access Journals (Sweden)

    quan-zhu Zhang

    2017-01-01

    Full Text Available On the standpoint of energy conservation and emission reduction, one device simulated photovoltaic grid-connected generation system based on SPWM was designed in the paper. And DC/AC inverter could transduce efficiently direct current to alternating current. The MCU(Micro-Control-Unit, in this system could achieve the control method for maximum-power-point and tracking for frequency and phase. Moreover, the MCU could implement PWM (Plus-Width Modulating through programming. The system showed clearly the whole photovoltaic grid-connected generation system using simulated methods and ways.

  13. Synchronization in single-phase grid-connected photovoltaic systems under grid faults

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede

    2012-01-01

    The highly increasing penetration of single-phase photovoltaic (PV) systems pushes the grid requirements related to the integration of PV power systems to be updated. These upcoming regulations are expected to direct the grid-connected renewable generators to support the grid operation and stabil......The highly increasing penetration of single-phase photovoltaic (PV) systems pushes the grid requirements related to the integration of PV power systems to be updated. These upcoming regulations are expected to direct the grid-connected renewable generators to support the grid operation...

  14. Grid Connected Solar PV System with SEPIC Converter Compared with Parallel Boost Converter Based MPPT

    OpenAIRE

    Bosco Raj, T. Ajith; Ramesh, R.; Maglin, J. R.; Vaigundamoorthi, M.; William Christopher, I.; Gopinath, C.; Yaashuwanth, C.

    2014-01-01

    The main objective of this work is to study the behaviour of the solar PV systems and model the efficient Grid-connected solar power system. The DC-DC MPPT circuit using chaotic pulse width modulation has been designed to track maximum power from solar PV module. The conversion efficiency of the proposed MPPT system is increased when CPWM is used as a control scheme. This paper also proposes a simplified multilevel (seven level) inverter for a grid-connected photovoltaic system. The primary g...

  15. Multiple effects of hydrological connectivity on floodplain processes in human modified river systems

    Science.gov (United States)

    Hein, Thomas; Bondar-Kunze, Elisabeth; Preiner, Stefan; Reckendorfer, Walter; Tritthart, Michael; Weigelhofer, Gabriele; Welti, Nina

    2014-05-01

    Floodplain and riparian ecosystems provide multiple functions and services of importance for human well-being and are of strategic importance for different sectors at catchment scale. Especially floodplains in the vicinity of urban areas can be areas of conflicting interests ranging from different land use types, flood water retention, drinking water production and recreation to conservation of last remnants of former riverine landscape, as it is the case in floodplains in the Danube Nationalpark downstream Vienna. Many of these ecosystem functions and services are controlled by the exchange conditions between river main channel and floodplain systems, the hydrological connectivity. At the same time these systems have been highly altered and especially the connectivity has been severely impaired. Thus, far ranging effects of changes in hydrological connectivity at various levels can be expected in altered floodplain systems. The aim of this presentation is to explore the complex control of different ecosystem functions and associated services by different parameters of hydrological connectivity, ranging from nutrient, sediment and matter dynamics and biodiversity aspects. Increasing connectivity will be shown to impact microbial dynamics, sediment-water interactions, carbon dynamics and trophic conditions, thus affecting the fundamental functions of particular floodplain systems at various spatial and temporal scales. Based on these changes also the provision of ecosystem services of floodplains is affected. The results clearly show that hydrological connectivity needs to be considered in a sustainable management approach.

  16. Connecting dissipation and noncommutativity: A Bateman system case study

    Science.gov (United States)

    Pal, Sayan Kumar; Nandi, Partha; Chakraborty, Biswajit

    2018-06-01

    We present an approach to the problem of quantization of the damped harmonic oscillator. To start with, we adopt the standard method of doubling the degrees of freedom of the system (Bateman form) and then, by introducing some new parameters, we get a generalized coupled set of equations from the Bateman form. Using the corresponding time-independent Lagrangian, quantum effects on a pair of Bateman oscillators embedded in an ambient noncommutative space (Moyal plane) are analyzed by using both path integral and canonical quantization schemes within the framework of the Hilbert-Schmidt operator formulation. Our method is distinct from those existing in the literature and where the ambient space was taken to be commutative. Our quantization shows that we end up again with a Bateman system except that the damping factor undergoes renormalization. Strikingly, the corresponding expression shows that the renormalized damping factor can be nonzero even if "bare" one is zero to begin with. In other words, noncommutativity can act as a source of dissipation. Conversely, the noncommutative parameter θ , taken to be a free one now, can be fine tuned to get a vanishing renormalized damping factor. This indicates in some sense a "duality" between dissipation and noncommutativity. Our results match the existing results in the commutative limit.

  17. A GRID-CONNECTED HYBRID WIND-SOLAR POWER SYSTEM

    Directory of Open Access Journals (Sweden)

    MAAMAR TALEB

    2017-06-01

    Full Text Available A hybrid renewable energy system consisting of a photovoltaic generator and a wind driven DC machine is interconnected with the power utilities grid. The interconnection is done through the use of two separate single phase full wave controlled bridge converters. The bridge converters are operated in the “inverter mode of operation”. That is to guaranty the extraction of the real powers from the wind driven generator as well as from the photovoltaic generator and inject them into the power utilities grid. At any pretended surrounding weather conditions, maximum extraction of powers from both renewable energy sources is targeted. This is done through the realization of self-adjusted firing angle controllers responsible of triggering the semiconductor elements of the controlled converters. An active power filter is shunted with the proposed setup to guaranty the sinusoid quality of the power utilities line current. The overall performance of the proposed system has been simulated in MATLAB/SIMULINK environment. Quite satisfactory and encouraging results have been obtained.

  18. Automatic generation of smart earthquake-resistant building system: Hybrid system of base-isolation and building-connection

    Directory of Open Access Journals (Sweden)

    M. Kasagi

    2016-02-01

    Full Text Available A base-isolated building may sometimes exhibit an undesirable large response to a long-duration, long-period earthquake ground motion and a connected building system without base-isolation may show a large response to a near-fault (rather high-frequency earthquake ground motion. To overcome both deficiencies, a new hybrid control system of base-isolation and building-connection is proposed and investigated. In this new hybrid building system, a base-isolated building is connected to a stiffer free wall with oil dampers. It has been demonstrated in a preliminary research that the proposed hybrid system is effective both for near-fault (rather high-frequency and long-duration, long-period earthquake ground motions and has sufficient redundancy and robustness for a broad range of earthquake ground motions.An automatic generation algorithm of this kind of smart structures of base-isolation and building-connection hybrid systems is presented in this paper. It is shown that, while the proposed algorithm does not work well in a building without the connecting-damper system, it works well in the proposed smart hybrid system with the connecting damper system.

  19. Considerations of coil protection and electrical connection schemes in large superconducting toroidal magnet system

    International Nuclear Information System (INIS)

    Yeh, H.T.

    1976-03-01

    A preliminary comparison of several different coil protection and electrical connection schemes for large superconducting toroidal magnet systems (STMS) is carried out. The tentative recommendation is to rely on external dump resistors for coil protection and to connect the coils in the toroidal magnet in several parallel loops (e.g., every fourth coil is connected into a single series loop). For the fault condition when a single coil quenches, the quenched coil should be isolated from its loop by switching devices. The magnet, as a whole, should probably be discharged if more than a few coils have quenched

  20. Policy incentives and grid-connected photovoltaics system development in China

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jing; Xu Yugao

    2007-07-01

    China has made considerable progress in solar PV generation technology. However, compared with conventional generation technologies or even other renewables such as wind and biomass, grid-connected PV technology is in its early stage and has not reached an adequate level of economic performance. Therefore, policy incentives will play important roles in attracting more social investments to facilitate the development of grid-connected PV generation. This paper is focused on analyzing the role of incentive policies in enhancing the market competitiveness of grid-connected solar PV systems in the context of China with an economic model and some policy suggestions are given based on simulation modeling efforts. (auth)

  1. Harmonic resonance assessment of multiple paralleled grid-connected inverters system

    DEFF Research Database (Denmark)

    Wang, Yanbo; Wang, Xiongfei; Blaabjerg, Frede

    2017-01-01

    This paper presents an eigenvalue-based impedance stability analytical method of multiple paralleled grid-connected inverter system. Different from the conventional impedance-based stability criterion, this work first built the state-space model of paralleled grid-connected inverters. On the basis...... of this, a bridge between the state-space-based modelling and impedance-based stability criterion is presented. The proposed method is able to perform stability assessment locally at the connection points of the component. Meanwhile, the eigenvalue-based sensitivity analysis is adopted to identify...

  2. Special issue on advancing grid-connected renewable generation systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Yang, Yongheng

    2017-01-01

    Renewables are heavily involved in power generation, as an essential component for today’s energy paradigm. Energy structure—both national and international—has been undergoing significant changes over the past few decades. For instance, in Denmark, power generation is shifting from fossil......-fuel-based to renewable-based in terms of energy sources, from centralized to decentralized in terms of architectures, and from sole to miscellaneous in terms of energy varieties [1]. In this energy evolution, the power electronic technology plays an enabling role in the integration and advancements of renewables......—such as wind turbine, photovoltaics, fuel cells, and other emerging energy systems. At the same time, various control strategies are necessary to guide the energy integration (i.e., to enhance the energy transition), and on the other hand, to flexibly, reliably, and efficiently utilize the energy. Tremendous...

  3. Statistical Analysis of the Grid Connected Photovoltaic System Performance Ratio

    Directory of Open Access Journals (Sweden)

    Javier Vilariño-García

    2017-05-01

    Full Text Available A methodology based on the application of variance analysis and Tukey's method to a data set of solar radiation in the plane of the photovoltaic modules and the corresponding values of power delivered to the grid at intervals of 10 minutes presents from sunrise to sunset during the 52 weeks of the year 2013. These data were obtained through a monitoring system located in a photovoltaic plant of 10 MW of rated power located in Cordoba, consisting of 16 transformers and 98 investors. The application of the comparative method among the middle of the performance index of the processing centers to detect with an analysis of variance if there is significant difference in average at least the rest at a level of significance of 5% and then by testing Tukey which one or more processing centers that are below average due to a fault to be detected and corrected are.

  4. Optimal system sizing in grid-connected photovoltaic applications

    Science.gov (United States)

    Simoens, H. M.; Baert, D. H.; de Mey, G.

    A costs/benefits analysis for optimizing the combination of photovoltaic (PV) panels, batteries and an inverter for grid interconnected systems at a 500 W/day Belgian residence is presented. It is assumed that some power purchases from the grid will always be necessary, and that excess PV power can be fed into the grid. A minimal value for the cost divided by the performance is defined for economic optimization. Shortages and excesses are calculated for PV panels of 0.5-10 kWp output, with consideration given to the advantages of a battery back-up. The minimal economic value is found to increase with the magnitude of PV output, and an inverter should never be rated at more than half the array maximum output. A maximum panel size for the Belgian residence is projected to be 6 kWp.

  5. Magnetism and magnetostriction in a degenerate rigid band

    International Nuclear Information System (INIS)

    Kulakowski, K.; Barbara, B.

    1990-09-01

    We investigate the influence of the spin-orbit coupling on the magnetic and magnetoelastic phenomena in ferromagnetic band systems. The description is within the Stoner model of a degenerate rigid band, for temperature T = O. (author). 14 refs

  6. Rigidity of Glasses and Macromolecules

    Science.gov (United States)

    Thorpe, M. F.

    1998-03-01

    The simple yet powerful ideas of percolation theory have found their way into many different areas of research. In this talk we show how RIGIDITY PERCOLATION can be studied at a similar level of sophistication, using a powerful new program THE PEBBLE GAME (D. J. Jacobs and M. F. Thorpe, Phys. Rev. E) 53, 3682 (1996). that uses an integer algorithm. This program can analyse the rigidity of two and three dimensional networks containing more than one million bars and joints. We find the total number of floppy modes, and find the critical behavior as the network goes from floppy to rigid as more bars are added. We discuss the relevance of this work to network glasses, and how it relates to experiments that involve the mechanical properties like hardness and elasticity of covalent glassy networks like Ge_xAs_ySe_1-x-y and dicuss recent experiments that suggest that the rigidity transition may be first order (Xingwei Feng, W. J.Bresser and P. Boolchand, Phys. Rev. Lett 78), 4422 (1997).. This approach is also useful in macromolecules and proteins, where detailed information about the rigid domain structure can be obtained.

  7. System performance of a three-phase PV-grid-connected system installed in Thailand. Data monitored analysis

    International Nuclear Information System (INIS)

    Boonmee, Chaiyant; Watjanatepin, Napat; Plangklang, Boonyang

    2009-01-01

    PV-grid-connected systems are worldwide installed because it allows consumer to reduce energy consumption from the electricity grid and to feed the surplus energy back into the grid. The system needs no battery so therefore the system price is very cheap comparing to other PV systems. PV-grid-connected systems are used in buildings that already hooked up to the electrical grid. Finding efficiency of the PV-grid-connected system can be done by using a standard instrument which needs to disconnect the PV arrays from the grid before measurement. The measurement is also difficult and we lose energy during the measurement. This paper will present the system performance of a PV-grid-connected system installed in Thailand by using a monitoring system. The monitored data are installed by acquisition software into a computer. Analysis of monitored data will be done to find out the system performance without disconnecting the PV arrays from the system. The monitored data include solar radiation, PV voltage, PV current, and PV power which has been recorded from a 5 kWp system installed of amorphous silicon PV at Rajamangala University of Technology Suvarnabhumi, Nonthaburi, Thailand. The system performance of the system by using the data monitored is compared to the standard instrument measurement. The paper will give all details about system components, monitoring system, and monitored data. The result of data analysis will be fully given. (author)

  8. Solar photovoltaic systems and their use as grid-connected generators in the United Kingdom

    Energy Technology Data Exchange (ETDEWEB)

    Munro, D K; Hacker, R J; Thornycroft, J M [Halcrow Gilbert Associates Ltd., Swindon (United Kingdom)

    1995-10-01

    There is an increasing interest in the use of building-integrated solar photovoltaic generators as grid-connected generators. This paper discusses the experience with this technology in Europe. Typical systems and their integration into domestic and non-domestic buildings are described. Information is provided on the energy output that can be expected from the systems and the economics of their use. The paper provides an overview of the requirements for photovoltaic systems as grid-connected generation plant in the United Kingdom. (Author)

  9. Cognitive Connected Vehicle Information System Design Requirement for Safety: Role of Bayesian Artificial Intelligence

    Directory of Open Access Journals (Sweden)

    Ata Khan

    2013-04-01

    Full Text Available Intelligent transportation systems (ITS are gaining acceptance around the world and the connected vehicle component of ITS is recognized as a high priority research and development area in many technologically advanced countries. Connected vehicles are expected to have the capability of safe, efficient and eco-driving operations whether these are under human control or in the adaptive machine control mode of operations. The race is on to design the capability to operate in connected traffic environment. The operational requirements can be met with cognitive vehicle design features made possible by advances in artificial intelligence-supported methodology, improved understanding of human factors, and advances in communication technology. This paper describes cognitive features and their information system requirements. The architecture of an information system is presented that supports the features of the cognitive connected vehicle. For better focus, information processing capabilities are specified and the role of Bayesian artificial intelligence is defined for data fusion. Example applications illustrate the role of information systems in integrating intelligent technology, Bayesian artificial intelligence, and abstracted human factors. Concluding remarks highlight the role of the information system and Bayesian artificial intelligence in the design of a new generation of cognitive connected vehicle.

  10. Positive semidefinite matrix completion, universal rigidity and the Strong Arnold Property

    NARCIS (Netherlands)

    M. Laurent (Monique); A. Varvitsiotis (Antonios)

    2014-01-01

    htmlabstractThis paper addresses the following three topics: positive semidefinite (psd) matrix completions, universal rigidity of frameworks, and the Strong Arnold Property (SAP). We show some strong connections among these topics, using semidefinite programming as unifying theme. Our main

  11. Benchmarking of Phase Locked Loop based Synchronization Techniques for Grid-Connected Inverter Systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Hadjidemetriou, Lenos; Blaabjerg, Frede

    2015-01-01

    Grid-connected renewables are increasingly developed in recent years, e.g. wind turbine systems and photovoltaic systems. Synchronization of the injected current with the grid is mandatory. However, grid disturbances like voltage sags, harmonics, and frequency deviations may occur during operatio...

  12. Variational and penalization methods for studying connecting orbits of Hamiltonian systems

    Directory of Open Access Journals (Sweden)

    Chao-Nien Chen

    2000-08-01

    Full Text Available In this article, we consider a class of second order Hamiltonian systems that possess infinite or finite number of equilibria. Variational arguments will be used to study the existence of connecting orbits joining pairs of equilibria. Applying penalization methods, we obtain various patterns for multibump homoclinics and heteroclinics of Hamiltonian systems.

  13. Hybrid Control System for Greater Resilience Using Multiple Isolation and Building Connection

    Directory of Open Access Journals (Sweden)

    Masaki Taniguchi

    2016-10-01

    Full Text Available An innovative hybrid control building system of multiple isolation and connection is proposed and investigated using both time-history and input energy responses for various types of ground motions together with transfer functions. It is concerned that the seismic displacement response at the base-isolation layer of the existing base-isolated buildings may extremely increase under long-period and long-duration ground motions which are getting great attention recently. In order to enhance the seismic performance of those base-isolated buildings, a novel hybrid system of multiple isolation and building-connection is proposed and compared with other structural systems such as an independent multiple isolation system, a hybrid system of base-isolation and building-connection. Furthermore, the robustness of seismic responses of the proposed hybrid system for various types of ground motion is discussed through the comparison of various structural systems including non-hybrid systems. Finally the optimal connection damper location is investigated using a sensitivity-type optimization approach.

  14. Digital proportional multi-resonant current controller for improving grid-connected photovoltaic systems

    NARCIS (Netherlands)

    Almeida, de P.M.; Barbosa, P.G.; Oliveira, J.G.; Duarte, J.L.; Ribeiro, P.F.

    2015-01-01

    This paper presents the modelling and design steps of a digital proportional multi-resonant controller used in a grid-connected photovoltaic (PV) system. It is shown that the use of only one Proportional-Resonant (PR) compensator, tuned to the system fundamental frequency, may have its effectiveness

  15. Optimizing electrical load pattern in Kuwait using grid connected photovoltaic systems

    International Nuclear Information System (INIS)

    Al-Hasan, A.Y.; Ghoneim, A.A.; Abdullah, A.H.

    2004-01-01

    Grid connected photovoltaic systems is one of the most promising applications of photovoltaic systems. These systems are employed in applications where utility service is already available. In this case, there is no need for battery storage because grid power may be used to supplement photovoltaic systems (PV) when the load exceeds available PV generation. The load receives electricity from both the photovoltaic array and the utility grid. In this system, the load is the total electrical energy consumption. The main objective of the present work is to optimize the electrical load pattern in Kuwait using grid connected PV systems. In this situation, the electric load demand can be satisfied from both the photovoltaic array and the utility grid. The performance of grid connected photovoltaic systems in the Kuwait climate has been evaluated. It was found that the peak load matches the maximum incident solar radiation in Kuwait, which would emphasize the role of using the PV station to minimize the electrical load demand. In addition, a significant reduction in peak load can be achieved with grid connected PV systems

  16. Rigidly foldable origami gadgets and tessellations

    Science.gov (United States)

    Evans, Thomas A.; Lang, Robert J.; Magleby, Spencer P.; Howell, Larry L.

    2015-01-01

    Rigidly foldable origami allows for motion where all deflection occurs at the crease lines and facilitates the application of origami in materials other than paper. In this paper, we use a recently discovered method for determining rigid foldability to identify existing flat-foldable rigidly foldable tessellations, which are also categorized. We introduce rigidly foldable origami gadgets which may be used to modify existing tessellations or to create new tessellations. Several modified and new rigidly foldable tessellations are presented. PMID:26473037

  17. Watershed erosion modeling using the probability of sediment connectivity in a gently rolling system

    Science.gov (United States)

    Mahoney, David Tyler; Fox, James Forrest; Al Aamery, Nabil

    2018-06-01

    Sediment connectivity has been shown in recent years to explain how the watershed configuration controls sediment transport. However, we find no studies develop a watershed erosion modeling framework based on sediment connectivity, and few, if any, studies have quantified sediment connectivity for gently rolling systems. We develop a new predictive sediment connectivity model that relies on the intersecting probabilities for sediment supply, detachment, transport, and buffers to sediment transport, which is integrated in a watershed erosion model framework. The model predicts sediment flux temporally and spatially across a watershed using field reconnaissance results, a high-resolution digital elevation models, a hydrologic model, and shear-based erosion formulae. Model results validate the capability of the model to predict erosion pathways causing sediment connectivity. More notably, disconnectivity dominates the gently rolling watershed across all morphologic levels of the uplands, including, microtopography from low energy undulating surfaces across the landscape, swales and gullies only active in the highest events, karst sinkholes that disconnect drainage areas, and floodplains that de-couple the hillslopes from the stream corridor. Results show that sediment connectivity is predicted for about 2% or more the watershed's area 37 days of the year, with the remaining days showing very little or no connectivity. Only 12.8 ± 0.7% of the gently rolling watershed shows sediment connectivity on the wettest day of the study year. Results also highlight the importance of urban/suburban sediment pathways in gently rolling watersheds, and dynamic and longitudinal distributions of sediment connectivity might be further investigated in future work. We suggest the method herein provides the modeler with an added tool to account for sediment transport criteria and has the potential to reduce computational costs in watershed erosion modeling.

  18. A Sensorless Power Reserve Control Strategy for Two-Stage Grid-Connected PV Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2017-01-01

    Due to the still increasing penetration of grid-connected Photovoltaic (PV) systems, advanced active power control functionalities have been introduced in grid regulations. A power reserve control, where namely the active power from the PV panels is reserved during operation, is required for grid...... support. In this paper, a cost-effective solution to realize the power reserve for two-stage grid-connected PV systems is proposed. The proposed solution routinely employs a Maximum Power Point Tracking (MPPT) control to estimate the available PV power and a Constant Power Generation (CPG) control...... performed on a 3-kW two-stage single-phase grid-connected PV system, where the power reserve control is achieved upon demands....

  19. Vision-based stress estimation model for steel frame structures with rigid links

    Science.gov (United States)

    Park, Hyo Seon; Park, Jun Su; Oh, Byung Kwan

    2017-07-01

    This paper presents a stress estimation model for the safety evaluation of steel frame structures with rigid links using a vision-based monitoring system. In this model, the deformed shape of a structure under external loads is estimated via displacements measured by a motion capture system (MCS), which is a non-contact displacement measurement device. During the estimation of the deformed shape, the effective lengths of the rigid link ranges in the frame structure are identified. The radius of the curvature of the structural member to be monitored is calculated using the estimated deformed shape and is employed to estimate stress. Using MCS in the presented model, the safety of a structure can be assessed gauge-freely. In addition, because the stress is directly extracted from the radius of the curvature obtained from the measured deformed shape, information on the loadings and boundary conditions of the structure are not required. Furthermore, the model, which includes the identification of the effective lengths of the rigid links, can consider the influences of the stiffness of the connection and support on the deformation in the stress estimation. To verify the applicability of the presented model, static loading tests for a steel frame specimen were conducted. By comparing the stress estimated by the model with the measured stress, the validity of the model was confirmed.

  20. Height system connection between island and mainland using a hydrodynamic model: a case study connecting the Dutch Wadden islands to the Amsterdam ordnance datum (NAP)

    Science.gov (United States)

    Slobbe, D. C.; Klees, R.; Verlaan, M.; Zijl, F.; Alberts, B.; Farahani, H. H.

    2018-03-01

    We present an efficient and flexible alternative method to connect islands and offshore tide gauges with the height system on land. The method uses a regional, high-resolution hydrodynamic model that provides total water levels. From the model, we obtain the differences in mean water level (MWL) between tide gauges at the mainland and at the islands or offshore platforms. Adding them to the MWL relative to the national height system at the mainland's tide gauges realizes a connection of the island and offshore platforms with the height system on the mainland. Numerical results are presented for the connection of the Dutch Wadden islands with the national height system (Normaal Amsterdams Peil, NAP). Several choices of the period over which the MWLs are computed are tested and validated. The best results were obtained when we computed the MWL only over the summer months of our 19-year simulation period. Based on this strategy, the percentage of connections for which the absolute differences between the observation- and model-derived MWL differences are ≤ 1 cm is about 34% (46 out of 135 possible leveling connections). In this case, for each Wadden island we can find several connections that allow the transfer of NAP with (sub-)centimeter accuracy.

  1. Stresses in Circular Plates with Rigid Elements

    Science.gov (United States)

    Velikanov, N. L.; Koryagin, S. I.; Sharkov, O. V.

    2018-05-01

    Calculations of residual stress fields are carried out by numerical and static methods, using the flat cross-section hypothesis. The failure of metal when exposed to residual stresses is, in most cases, brittle. The presence in the engineering structures of rigid elements often leads to the crack initiation and structure failure. This is due to the fact that rigid elements under the influence of external stresses are stress concentrators. In addition, if these elements are fixed by welding, the residual welding stresses can lead to an increase in stress concentration and, ultimately, to failure. The development of design schemes for such structures is a very urgent task for complex technical systems. To determine the stresses in a circular plate with a welded circular rigid insert under the influence of an external load, one can use the solution of the plane stress problem for annular plates in polar coordinates. The polar coordinates of the points are the polar radius and the polar angle, and the stress state is determined by normal radial stresses, tangential and shearing stresses. The use of the above mentioned design schemes, formulas, will allow more accurate determination of residual stresses in annular welded structures. This will help to establish the most likely directions of failure and take measures at the stages of designing, manufacturing and repairing engineering structures to prevent these failures. However, it must be taken into account that the external load, the presence of insulation can lead to a change in the residual stress field.

  2. The Study on Hybrid Multi-Infeed HVDC System Connecting with Offshore Wind Farm

    DEFF Research Database (Denmark)

    Liu, Yan

    furnish the VSC-HVDC connected wind farm with a fast and reliable LVRT ability. The voltage fluctuation caused by the intermittent wind power is another important challenge to the system stability. As in the case of the LCC-HVDC links, their stable operations are highly dependent on the AC side voltage...... with the short electrical distance. And consequently, a so-called Multi-Infeed Direct Current (MIDC) transmission system is formed. On the other hand, as the fast growing of wind power in electrical grids, the Voltage Source Converter based HVDC (VSC-HVDC) links have becoming a favorable choice for connecting...

  3. Anesthetic implications of total anomalous systemic venous connection to left atrium with left isomerism

    Directory of Open Access Journals (Sweden)

    Parimala Prasanna Simha

    2012-01-01

    Full Text Available Total anomalous systemic venous connection (TASVC to the left atrium (LA is a rare congenital anomaly. An 11-year-old girl presented with complaints of palpitations and cyanosis. TASVC with left isomerism and noncompaction of LV was diagnosed after contrast echocardiogram and computed tomography angiogram. The knowledge of anatomy and pathophysiology is essential for the successful management of these cases. Anesthetic concerns in this case were polycythemia, paradoxical embolism and rhythm abnormalities. The patient was successfully operated by rerouting the systemic venous connection to the right atrium.

  4. Decentralized electricity generation by using photovoltaic grid-connected solar system

    International Nuclear Information System (INIS)

    Tyutyundziev, N.; Vitanov, P.; Radkov, R.; Grottke, M.

    2006-01-01

    AcadPV is the first demonstration installation connected permanently to LV grid in Sofia, Bulgaria aiming at assessment of PV efficiencies and cost-effectiveness. A thorough analysis has been carried out in order to select PV system site, supporting construction design and orientation. The PV generator is divided to 3 PV subfields equipped by 3 SUNPOWER inverters connected to 3 separated phases of the grid. The performance of 10kWp PV system has been evaluated during the first year of operation and compared to PV simulation software results

  5. Experimental evaluation of 8kW grid-connected photovoltaic system in Egypt

    OpenAIRE

    Elkholy, A.; Fahmy, F.H.; Abou El-Ela, A.A.; Nafeh, Abd El-Shafy A.; Spea, S.R.

    2016-01-01

    An experimental observation study of 8 kW grid-connected photovoltaic (PV) system that is installed at Electronics Research Institute (ERI), Giza, Egypt (Latitude 30.04°N, Longitude 31.21°E), is presented. This study includes the quality of the electrical power generated and injected into the network. The considered system consists of 28 × 295 Wp multicrystalline PV modules, StecaGrid three-phase 8 kW grid-connected inverter and a Solar-Log 300 PM+ for data acquisition and remote monitoring. ...

  6. Motor imagery learning modulates functional connectivity of multiple brain systems in resting state.

    Science.gov (United States)

    Zhang, Hang; Long, Zhiying; Ge, Ruiyang; Xu, Lele; Jin, Zhen; Yao, Li; Liu, Yijun

    2014-01-01

    Learning motor skills involves subsequent modulation of resting-state functional connectivity in the sensory-motor system. This idea was mostly derived from the investigations on motor execution learning which mainly recruits the processing of sensory-motor information. Behavioral evidences demonstrated that motor skills in our daily lives could be learned through imagery procedures. However, it remains unclear whether the modulation of resting-state functional connectivity also exists in the sensory-motor system after motor imagery learning. We performed a fMRI investigation on motor imagery learning from resting state. Based on previous studies, we identified eight sensory and cognitive resting-state networks (RSNs) corresponding to the brain systems and further explored the functional connectivity of these RSNs through the assessments, connectivity and network strengths before and after the two-week consecutive learning. Two intriguing results were revealed: (1) The sensory RSNs, specifically sensory-motor and lateral visual networks exhibited greater connectivity strengths in precuneus and fusiform gyrus after learning; (2) Decreased network strength induced by learning was proved in the default mode network, a cognitive RSN. These results indicated that resting-state functional connectivity could be modulated by motor imagery learning in multiple brain systems, and such modulation displayed in the sensory-motor, visual and default brain systems may be associated with the establishment of motor schema and the regulation of introspective thought. These findings further revealed the neural substrates underlying motor skill learning and potentially provided new insights into the therapeutic benefits of motor imagery learning.

  7. Motor Imagery Learning Modulates Functional Connectivity of Multiple Brain Systems in Resting State

    Science.gov (United States)

    Zhang, Hang; Long, Zhiying; Ge, Ruiyang; Xu, Lele; Jin, Zhen; Yao, Li; Liu, Yijun

    2014-01-01

    Background Learning motor skills involves subsequent modulation of resting-state functional connectivity in the sensory-motor system. This idea was mostly derived from the investigations on motor execution learning which mainly recruits the processing of sensory-motor information. Behavioral evidences demonstrated that motor skills in our daily lives could be learned through imagery procedures. However, it remains unclear whether the modulation of resting-state functional connectivity also exists in the sensory-motor system after motor imagery learning. Methodology/Principal Findings We performed a fMRI investigation on motor imagery learning from resting state. Based on previous studies, we identified eight sensory and cognitive resting-state networks (RSNs) corresponding to the brain systems and further explored the functional connectivity of these RSNs through the assessments, connectivity and network strengths before and after the two-week consecutive learning. Two intriguing results were revealed: (1) The sensory RSNs, specifically sensory-motor and lateral visual networks exhibited greater connectivity strengths in precuneus and fusiform gyrus after learning; (2) Decreased network strength induced by learning was proved in the default mode network, a cognitive RSN. Conclusions/Significance These results indicated that resting-state functional connectivity could be modulated by motor imagery learning in multiple brain systems, and such modulation displayed in the sensory-motor, visual and default brain systems may be associated with the establishment of motor schema and the regulation of introspective thought. These findings further revealed the neural substrates underlying motor skill learning and potentially provided new insights into the therapeutic benefits of motor imagery learning. PMID:24465577

  8. A new system of implant abutment connection: how to improve a two piece implant system sealing.

    Science.gov (United States)

    Grecchi, F; DI Girolamo, M; Cura, F; Candotto, V; Carinci, F

    2017-01-01

    Implant dentistry has become one of the most successful dentistry techniques for replacing missing teeth. The success rate of implant dentistry is above 80%. However, peri-implantitis is a later complication of implant dentistry that if untreated, can lead to implant loss. One of the hypotized causes of peri-implantis is the bacterial leakage at the level of implant-abutment connection. Bacterial leakage is favored to the presence of a micro gap at the implant-abutment interface, allowing microorganisms to penetrate and colonize the inner part of the implant leading to biofilm accumulation and consequently to peri-implantitis development. To identify the capability of the implant to protect the internal space from the external environment, the passage of genetically modified Escherichia coli across implant-abutment interface was evaluated. Implants were immerged in a bacterial culture for twenty-four hours and then bacteria amount was measured inside implant-abutment interface with Real-time PCR. Bacteria were detected inside all studied implants, with a median percentage of 9%. The reported results are better to those of previous studies carried out on different implant systems. Until now, none implant-abutment system has been proven to seal the gap between implant and abutment.

  9. Power system stabilization by superconducting magnetic energystorage connected to rotating exciter

    OpenAIRE

    Mitani, Yasunori; Tsuji, K

    1993-01-01

    The authors describe a combination of a rotating exciter and a superconducting magnetic energy storage (SMES) system for efficient power system stabilization. A SMES system connected to an exciter rotating with a turbine-rotor shaft is proposed. The exciter is installed exclusively to supply current for the SMES. Since electrical power output from the SMES is converted into a mechanical torque of the generator directly by the exciter, it is expected that power swings of the generator will be ...

  10. Impact of SONET digital cross-connect system architecture on distributed restoration

    International Nuclear Information System (INIS)

    Wu, Tsong-ho; Kobrinski, H.; Lakshman, T.V.

    1994-01-01

    The viability of distributed control restoration using Digital Cross-Connect Systems (DC's) depends on its capability for restoring services within specified time requirements, and its economics for providing restoration compared to other alternatives. In this paper, we report a Bellcore study for the impact of the DCS architecture on distributed restoration. This study concludes that currently proposed distributed control DCS self-healing schemes may not meet the 2-s restoration objective for large metropolitan Local Exchange Carrier's networks, regardless of the distributed algorithm used, if the present DCS system architecture which uses serial message processing and serial path cross-connection remains unchanged. This paper also discusses several DCS architecture enhancement options, including a parallel processing/cross-connect DCS architecture, which may improve the service restoration time. 20 refs

  11. Research on Experiment of Islanding Protection Device of Grid-connected Photovoltaic System Based on RTDS

    Science.gov (United States)

    Zhou, Ning; Yang, Jia; Cheng, Zheng; Chen, Bo; Su, Yong Chun; Shu, Zhan; Zou, Jin

    2017-06-01

    Solar photovoltaic power generation is the power generation using solar cell module converting sunlight into DC electric energy. In the paper an equivalent model of solar photovoltaic power generation system is built in RTDS. The main circuit structure of the two-stage PV grid-connected system consists of the DC-DC, DC-AC circuit. The MPPT (Maximum Power Point Tracking) control of the PV array is controlled by adjusting the duty ratio of the DC-DC circuit. The proposed control strategy of constant voltage/constant reactive power (V/Q) control is successfully implemented grid-connected control of the inverter when grid-connected operation. The closed-loop experiment of islanding protection device of photovoltaic power plant on RTDS, verifies the correctness of the simulation model, and the experimental verification can be applied to this type of device.

  12. Elastin Cables Define the Axial Connective Tissue System in the Murine Lung.

    Science.gov (United States)

    Wagner, Willi; Bennett, Robert D; Ackermann, Maximilian; Ysasi, Alexandra B; Belle, Janeil; Valenzuela, Cristian D; Pabst, Andreas; Tsuda, Akira; Konerding, Moritz A; Mentzer, Steven J

    2015-11-01

    The axial connective tissue system is a fiber continuum of the lung that maintains alveolar surface area during changes in lung volume. Although the molecular anatomy of the axial system remains undefined, the fiber continuum of the lung is central to contemporary models of lung micromechanics and alveolar regeneration. To provide a detailed molecular structure of the axial connective tissue system, we examined the extracellular matrix of murine lungs. The lungs were decellularized using a 24 hr detergent treatment protocol. Systematic evaluation of the decellularized lungs demonstrated no residual cellular debris; morphometry demonstrated a mean 39 ± 7% reduction in lung dimensions. Scanning electron microscopy (SEM) demonstrated an intact structural hierarchy within the decellularized lung. Light, fluorescence, and SEM of precision-cut lung slices demonstrated that alveolar duct structure was defined by a cable line element encased in basement membrane. The cable line element arose in the distal airways, passed through septal tips and inserted into neighboring blood vessels and visceral pleura. The ropelike appearance, collagenase resistance and anti-elastin immunostaining indicated that the cable was an elastin macromolecule. Our results indicate that the helical line element of the axial connective tissue system is composed of an elastin cable that not only defines the structure of the alveolar duct, but also integrates the axial connective tissue system into visceral pleura and peripheral blood vessels. © 2015 Wiley Periodicals, Inc.

  13. Frequency scanning-based stability analysis method for grid-connected inverter system

    DEFF Research Database (Denmark)

    Wang, Yanbo; Wang, Xiongfei; Blaabjerg, Frede

    2017-01-01

    This paper proposes a frequency scanning-based impedance analysis for stability assessment of grid-connected inverter system, which is able to perform stability assessment without using system mathematical models and inherit the superior feature of impedance-based stability criterion with conside......This paper proposes a frequency scanning-based impedance analysis for stability assessment of grid-connected inverter system, which is able to perform stability assessment without using system mathematical models and inherit the superior feature of impedance-based stability criterion...... with consideration of the inverter nonlinearities. Small current disturbance is injected into grid-connected inverter system in a particular frequency range, and the impedance is computed according to the harmonic-frequency response using Fourier analysis, and then the stability is predicted on the basis...... of the impedance stability criterion. The stability issues of grid-connected inverters with grid-current feedback and the converter-current feedback are addressed using the proposed method. The results obtained from simulation and experiments validate the effectiveness of the method. The frequency scanning...

  14. Quantitative Analysis Method of Output Loss due to Restriction for Grid-connected PV Systems

    Science.gov (United States)

    Ueda, Yuzuru; Oozeki, Takashi; Kurokawa, Kosuke; Itou, Takamitsu; Kitamura, Kiyoyuki; Miyamoto, Yusuke; Yokota, Masaharu; Sugihara, Hiroyuki

    Voltage of power distribution line will be increased due to reverse power flow from grid-connected PV systems. In the case of high density grid connection, amount of voltage increasing will be higher than the stand-alone grid connection system. To prevent the over voltage of power distribution line, PV system's output will be restricted if the voltage of power distribution line is close to the upper limit of the control range. Because of this interaction, amount of output loss will be larger in high density case. This research developed a quantitative analysis method for PV systems output and losses to clarify the behavior of grid connected PV systems. All the measured data are classified into the loss factors using 1 minute average of 1 second data instead of typical 1 hour average. Operation point on the I-V curve is estimated to quantify the loss due to the output restriction using module temperature, array output voltage, array output current and solar irradiance. As a result, loss due to output restriction is successfully quantified and behavior of output restriction is clarified.

  15. How to secure the connection between thoracostomy tube and drainage system?

    Science.gov (United States)

    Li, Ka Ki Pat; Wong, Kit Shing John; Wong, Yau Hang Henry; Cheng, Ka Lok; So, Fung Ling; Lau, Chu Leung; Kam, Chak Wah

    2014-01-01

    Thoracostomy tube insertion is one of the common bedside procedures in emergency medicine and many acute specialties. Dislodgement of thoracostomy tube from the connection tube of chest drainage system is an important problem with potential complications such as contamination, infection and pneumothorax. Besides, mere loosening can also lead to malfunction. It is a common practice to tape the connection of the system. This study aimed to evaluate the materials and methods of connection of chest drain system to minimize drainage dislodgement. We conducted an experimental study to assess the tightness of the connection with various taping materials and methods. We selected three commonly used adhesive materials (3M™ Transpore™ Medical tape, 3M™ Micropore™ Medical tape, 3M™ Soft Cloth Tape on Liner) and three different methods (cross method, straight method, nylon band) to secure the junction between the thoracostomy tube and the bi-conical adaptor in the drainage system. The measured outcome was the weight causing visible loosening of the junction between thoracotomy tube and the adaptor. For each taping material and taping method, 10 trials were performed. The median weight required to disconnect the junction is 26.22 lb for Transpore™, 31.29 lb for Micropore™ and 32.44 lb for Soft Cloth Tape on Liner. A smaller force was required to disconnect if Transpore™ is used (Ptube to the chest drainage system. Transpore™ is not a recommended material for thoracostomy tube taping.

  16. Study on optimal configuration of the grid-connected wind-solar-battery hybrid power system

    Science.gov (United States)

    Ma, Gang; Xu, Guchao; Ju, Rong; Wu, Tiantian

    2017-08-01

    The capacity allocation of each energy unit in the grid-connected wind-solar-battery hybrid power system is a significant segment in system design. In this paper, taking power grid dispatching into account, the research priorities are as follows: (1) We establish the mathematic models of each energy unit in the hybrid power system. (2) Based on dispatching of the power grid, energy surplus rate, system energy volatility and total cost, we establish the evaluation system for the wind-solar-battery power system and use a number of different devices as the constraint condition. (3) Based on an improved Genetic algorithm, we put forward a multi-objective optimisation algorithm to solve the optimal configuration problem in the hybrid power system, so we can achieve the high efficiency and economy of the grid-connected hybrid power system. The simulation result shows that the grid-connected wind-solar-battery hybrid power system has a higher comprehensive performance; the method of optimal configuration in this paper is useful and reasonable.

  17. Hydrodynamic modeling of hydrologic surface connectivity within a coastal river-floodplain system

    Science.gov (United States)

    Castillo, C. R.; Guneralp, I.

    2017-12-01

    Hydrologic surface connectivity (HSC) within river-floodplain environments is a useful indicator of the overall health of riparian habitats because it allows connections amongst components/landforms of the riverine landscape system to be quantified. Overbank flows have traditionally been the focus for analyses concerned with river-floodplain connectivity, but recent works have identified the large significance from sub-bankfull streamflows. Through the use of morphometric analysis and a digital elevation model that is relative to the river water surface, we previously determined that >50% of the floodplain for Mission River on the Coastal Bend of Texas becomes connected to the river at streamflows well-below bankfull conditions. Guided by streamflow records, field-based inundation data, and morphometric analysis; we develop a two-dimensional hydrodynamic model for lower portions of Mission River Floodplain system. This model not only allows us to analyze connections induced by surface water inundation, but also other aspects of the hydrologic connectivity concept such as exchanges of sediment and energy between the river and its floodplain. We also aggregate hydrodynamic model outputs to an object/landform level in order to analyze HSC and associated attributes using measures from graph/network theory. Combining physically-based hydrodynamic models with object-based and graph theoretical analyses allow river-floodplain connectivity to be quantified in a consistent manner with measures/indicators commonly used in landscape analysis. Analyzes similar to ours build towards the establishment of a formal framework for analyzing river-floodplain interaction that will ultimately serve to inform the management of riverine/floodplain environments.

  18. A Study of the Bolt Connection System for a Concrete Barrier of a Modular Bridge

    Directory of Open Access Journals (Sweden)

    Doo-Yong Cho

    2018-04-01

    Full Text Available Modular technology has been recently studied to reduce the construction periods in the field of bridge construction. However, this method is restricted to the pier, girder, and deck, which are the main members of a bridge, and incidental facilities such as concrete barriers have been rarely studied. Thus, in this study, the connection system of a concrete barrier for modular bridges was developed, and a static loading experiment was performed to verify the structural capacity of the proposed system. The variables of the experiment were the vertical and horizontal bolt connections and the construction method. The barrier and plate were fabricated using match casting methods in which nuts were first inserted into the plates rather than anchor bolts using the conservative method. Moreover, a comparison with the conventional in situ barrier was also performed. The experiments were conducted according to the AASHTO LRFD standard. Consequently, the specimen using the vertical bolt connection had a structural capacity that was equal to 85% of that of the conventional specimen and exhibited similar crack patterns compared with the conventional specimen. In the case of the horizontal bolt connection, the separation in the connection area occurred with the application of the initial load and this specimen exhibited a poor performance because of the increase in the separation distance with the application of the maximum load.

  19. Experimental Evaluation of the Failure of a Seismic Design Category - B Precast Concrete Beam-Column Connection System

    Science.gov (United States)

    2014-12-01

    Precast Concrete Beam - Column Connection ...ERDC TR-14-12 December 2014 Experimental Evaluation of the Failure of a Seismic Design Category – B Precast Concrete Beam - Column Connection ...systems in order to develop a methodology and obtain basic insight for predicting the brittle failure of precast beam - column connections under

  20. Is it possible to preserve lumbar lordosis after hybrid stabilization? Preliminary results of a novel rigid-dynamic stabilization system in degenerative lumbar pathologies.

    Science.gov (United States)

    Formica, Matteo; Cavagnaro, Luca; Basso, Marco; Zanirato, Andrea; Felli, Lamberto; Formica, Carlo

    2015-11-01

    To evaluate the results of a novel rigid-dynamic stabilization technique in lumbar degenerative segment diseases (DSD), expressly pointing out the preservation of postoperative lumbar lordosis (LL). Forty-one patients with one level lumbar DSD and initial disc degeneration at the adjacent level were treated. Circumferential lumbar arthrodesis and posterior hybrid instrumentation were performed to preserve an initial disc degeneration above the segment that has to be fused. Clinical and spino-pelvic parameters were evaluated pre- and postoperatively. At 2-year follow-up, a significant improvement of clinical outcomes was reported. No statistically significant difference was noted between postoperative and 2-year follow-up in LL and in disc/vertebral body height ratio at the upper adjacent fusion level. When properly selected, this technique leads to good results. A proper LL should be achieved after any hybrid stabilization to preserve the segment above the fusion.

  1. On the electronic structure of Barrelene-based rigid organic donor-acceptor systems. An INDO model study including solvent effects

    International Nuclear Information System (INIS)

    Fox, T.; Kotzian, M.; Roesch, N.

    1992-01-01

    The authors present an INDO/S Molecular-orbital investigation of organic molecules containing a barrelene moiety that provides a rigid link between an aromatic donor and a maleic ester acceptor group. Molecules of this type have recently been synthesized and characterized spectroscopically. The authors discuss the ground state and various excited states both in vacuo and in solution. Solvent effects are incorporated by use of an electrostatic cavity model which is not restricted to a spherical cavity, but allows for a cavity shape that is adapted to the solute molecule. The calculations indicate low-lying charge-transfer (CT) excitations in the region of the first aromatic transitions, even in the gas phase

  2. Influencia de un bloque rígido en un sistema de fallas de rumbo: modelamiento análogo Influence of a rigid block in a strike-slip fault system: analogue modelling

    Directory of Open Access Journals (Sweden)

    Thierry Nalpas

    2011-01-01

    Full Text Available En este trabajo se presenta un estudio de modelamiento análogo sobre la naturaleza, geometría y cinemática de la deformación a lo largo de fallas de rumbo dada la presencia de un bloque rígido en su trayectoria de deformación. Los modelos análogos están apropiadamente escalados considerando las características reológicas de los materiales que se desean contrastar en la deformación. Dos grandes parámetros fueron probados: la configuración del bloque rígido, variando su forma y tamaño, y el monto del desplazamiento. Los resultados experimentales muestran el desarrollo de rotaciones, fallas y pliegues como producto de la presencia de un bloque rígido en la trayectoria de falla. Los diversos casos geométricos probados pueden ser empleados para su comparación con sistemas de fallas de rumbo en los cuales existen diferencias litológicas de comportamiento reológico diferencial, como por ejemplo el caso del 'Núcleo rígido de Limón Verde' al sur de Chuquicamata, ubicado en la trayectoria del sistema de fallas de Domeyko.This work addresses the kinematic effects of a rigid block in strike-slip systems by using analogue models. The experiments (size, behaviour of materials were scaled down in order to represent deformation of the tested rheologic contrast conditions in deformation. Two main parameters were tested: the configuration of the rigid block, changing its form and size, and the amount of displacement. The experiments evidenced the development of rotations, faults and folds along the fault trajectory, as resulting from the presence of the rigid block during the deformation. Testing of diverse geometric situations may be used for comparison to strike-slip fault systems in which different lithologies and rheologic behaviour exist, for example, presence of the 'Limón Verde rigid core' along the Domeyko fault system, just south of Chuquicamata.

  3. Modeling and power system stability of VSC-HVDC systems for grid-connection of large offshore windfarms

    Energy Technology Data Exchange (ETDEWEB)

    Xue Yijing [Vestas China, Beijing (China); Akhmatov, Vladislav [Technical Univ. of Denmark, Lyngby (Denmark). Centre for Electric Technology

    2009-07-01

    Utilization of Voltage Source Converter (VSC) - High Voltage Direct Current (HVDC) systems for grid-connection of large offshore windfarms becomes relevant as installed power capacities as well as distances to the connection points of on-land transmission systems increase. At the same time, the grid code requirements of the Transmission System Operators (TSO), including ancillary system services and Low-Voltage Fault-Ride-Through (LVFRT) capability of large offshore windfarms, become more demanding. This paper presents a general-level model of and a LVFRT solution for a VSC-HVDC system for grid-connection of large offshore windfarms. The VSC-HVDC model is implemented using a general approach of independent control of active and reactive power in normal operations. The on-land VSC inverter, i.e. a grid-side inverter, provides voltage support to the transmission system and comprises a LVFRT solution in short-circuit faults. The presented model, LVFRT solution and impact on the system stability are investigated as a case study of a 1,000 MW offshore windfarm grid-connected through a VSC-HVDC system. The investigation is carried out on a model of the west Danish, with some elements of the north German, 400 kV, 220 kV and 150 kV transmission systems stage 2005-2006 using the DIgSILENT PowerFactory simulation program. In the investigation, a thermal power plant just south to the Danish border has been substituted by this 1,000 MW offshore windfarm utilizing the VSC-HVDC system. The investigation has shown that the substitution of a thermal power plant by a VSC-HVDC connected offshore windfarm should not have any negative impact on the short-term stability of the west Danish transmission system. The investigation should be repeated applying updated system model stages and offshore wind power commissioning schedules in the North and Baltic Seas. (orig.)

  4. Systemic inflammation and resting state connectivity of the default mode network.

    Science.gov (United States)

    Marsland, Anna L; Kuan, Dora C-H; Sheu, Lei K; Krajina, Katarina; Kraynak, Thomas E; Manuck, Stephen B; Gianaros, Peter J

    2017-05-01

    The default mode network (DMN) encompasses brain systems that exhibit coherent neural activity at rest. DMN brain systems have been implicated in diverse social, cognitive, and affective processes, as well as risk for forms of dementia and psychiatric disorders that associate with systemic inflammation. Areas of the anterior cingulate cortex (ACC) and surrounding medial prefrontal cortex (mPFC) within the DMN have been implicated specifically in regulating autonomic and neuroendocrine processes that relate to systemic inflammation via bidirectional signaling mechanisms. However, it is still unclear whether indicators of inflammation relate directly to coherent resting state activity of the ACC, mPFC, or other areas within the DMN. Accordingly, we tested whether plasma interleukin (IL)-6, an indicator of systemic inflammation, covaried with resting-state functional connectivity of the DMN among 98 adults aged 30-54 (39% male; 81% Caucasian). Independent component analyses were applied to resting state fMRI data to generate DMN connectivity maps. Voxel-wise regression analyses were then used to test for associations between IL-6 and DMN connectivity across individuals, controlling for age, sex, body mass index, and fMRI signal motion. Within the DMN, IL-6 covaried positively with connectivity of the sub-genual ACC and negatively with a region of the dorsal medial PFC at corrected statistical thresholds. These novel findings offer evidence for a unique association between a marker of systemic inflammation (IL-6) and ACC and mPFC functional connectivity within the DMN, a network that may be important for linking aspects of immune function to psychological and behavioral states in health and disease. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Dynamics of voltage source converter in a grid connected solar photovoltaic system

    DEFF Research Database (Denmark)

    Haribabu, Divyanagalakshmi; Vangari, Adithya; Sakamuri, Jayachandra N.

    2015-01-01

    This paper emphasises the modelling and control of a voltage source converter (VSC) for three phase grid connected PV system. The transfer functions for inner current control and outer DC link voltage control for VSC are derived. The controllers for VSC are designed based on PI and K factor contr...

  6. Online Energy Management System for Distributed Generators in a Grid-Connected Microgrid

    DEFF Research Database (Denmark)

    Hernández, Adriana Carolina Luna; Aldana, Nelson Leonardo Diaz; Graells, Moises

    2015-01-01

    A microgrid is an energy subsystem composed of generation units, energy storage, and loads that requires power management in order to supply the load properly according to defined objectives. This paper proposes an online energy management system for a storage based grid-connected microgrid...

  7. Control of a battery energy storage system connected to a low voltage grid

    NARCIS (Netherlands)

    van Dun, J.J.C.M.; de Groot, Robert; Morren, Johan; Slootweg, Han

    2015-01-01

    This paper describes the development of a control algorithm for a battery energy storage system, which is connected to a residential low voltage grid. By predicting future load demand and photovoltaic production within the neighbourhood concerned, flattening of the aggregated neighbourhood

  8. The elaboration of a manufacturing flow connectivity model, based on Multi Agent System

    Directory of Open Access Journals (Sweden)

    Fahhama Lamyae

    2017-01-01

    The aim of this paper was to establish a model of the industrial flow connectivity; Afterward, we’ve detailed a network configuration model based on the multi-agents systems, to study the interactions between all the actors and give a more realistic vision onto manufacturing coordination in the supply chain.

  9. NBAS mutations cause a multisystem disorder involving bone, connective tissue, liver, immune system, and retina

    NARCIS (Netherlands)

    Segarra, Nuria Garcia; Ballhausen, Diana; Crawford, Heather; Perreau, Matthieu; Campos-Xavier, Belinda; van Spaendonck-Zwarts, Karin; Vermeer, Cees; Russo, Michel; Zambelli, Pierre-Yves; Stevenson, Brian; Royer-Bertrand, Beryl; Rivolta, Carlo; Candotti, Fabio; Unger, Sheila; Munier, Francis L.; Superti-Furga, Andrea; Bonafé, Luisa

    2015-01-01

    We report two unrelated patients with a multisystem disease involving liver, eye, immune system, connective tissue, and bone, caused by biallelic mutations in the neuroblastoma amplified sequence (NBAS) gene. Both presented as infants with recurrent episodes triggered by fever with vomiting,

  10. Benchmarking of Constant Power Generation Strategies for Single-Phase Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2016-01-01

    With a still increase of grid-connected Photovoltaic (PV) systems, challenges have been imposed on the grid due to the continuous injection of a large amount of fluctuating PV power, like overloading the grid infrastructure (e.g., transformers) during peak power production periods. Hence, advanced...

  11. Development and Evaluation of cooperative control system for an HVDC transmission system connected with an isolated BWR power plant

    International Nuclear Information System (INIS)

    Horiuchi, Susumu; Hara, Tsukusi; Matori, Iwao; Hirayama, Kaiichirou.

    1987-01-01

    In the cooperative control system developed for an HVDC transmission system connected with an isolated BWR power plant, the equilibrium state between power plant output and DC transmission power is examined by way of the detection of the generator frequency. And, thereby start-up and shutdown of the DC system and controlling of the transmission power are made, so that the signal transmission with the power plant becomes unnecessary, enabling the easy cooperative operation. In order to investigate validity of this control system, various digital simulation and simulator test with the control system were carried out. In this way, behavior of the power plant and stability of the DC transmission system were evaluated in the connection to the DC system at power plant start-up, follow of the transmission power in change of the power plant output and in various system failures. (Mori, K.)

  12. Verification of the Rigidity of the Coulomb Field in Motion

    Science.gov (United States)

    Blinov, S. V.; Bulyzhenkov, I. É.

    2018-06-01

    Laplace, analyzing the stability of the Solar System, was the first to calculate that the velocity of the motion of force fields can significantly exceed the velocity of light waves. In electrodynamics, the Coulomb field should rigidly accompany its source for instantaneous force action in distant regions. Such rigid motion was recently inferred from experiments at the Frascati Beam Test Facility with short beams of relativistic electrons. The comments of the authors on their observations are at odds with the comments of theoreticians on retarded potentials, which motivates a detailed study of the positions of both sides. Predictions of measurements, based on the Lienard-Wiechert potentials, are used to propose an unambiguous scheme for testing the rigidity of the Coulomb field. Realization of the proposed experimental scheme could independently refute or support the assertions of the Italian physicists regarding the rigid motion of Coulomb fields and likewise the nondual field approach to macroscopic reality.

  13. A new PLL system using full order observer and PLL system modeling in a single phase grid-connected inverter

    DEFF Research Database (Denmark)

    Ko, Youngjong; Park, Kiwoo; Lee, Kyo-Beum

    2011-01-01

    In a grid connected power conversion system, the phase angle information of a grid voltage is very essential for supplying power to the grid since it is used for active and reactive power control. A Phase Locked Loop (PLL) system is used and should be robust because often the actual grid voltages...

  14. A Novel Flying Capacitor Transformerless Inverter for Single-Phase Grid Connected Solar Photovoltaic System

    DEFF Research Database (Denmark)

    Siwakoti, Yam Prasad; Blaabjerg, Frede

    2016-01-01

    This paper proposes a new single-phase flying capacitor transformerless PV inverter for grid-connected photovoltaic (PV) systems. The neutral of the grid can be directly connected to the negative terminal of the source (PV). It consists of four power switches, one diode, one capacitor and a small...... and some topologies, which requires two times of the peak ac-voltage magnitude) and, (5) the flying capacitor charges every switching cycle, which reduces the size of the required capacitor with switching frequency. In addition, industry standard half bridge module can be used in the new inverter without...

  15. Mission Profile Translation to Capacitor Stresses in Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Ma, Ke; Wang, Huai

    2014-01-01

    DC capacitors are widely adopted in grid-connected PhotoVoltaic(PV) systems for power stabilization and control decoupling. They have become one of the critical components in grid-connected PV inverters in terms of cost, reliability and volume. The electrical and thermal stresses of the DC...... stresses of the DC capacitors under both normal and abnormal grid conditions. As a consequence, this investigation provides new insights into the sizing and reliability prediction of those capacitors with respect to priorart studies. Two study cases on a single-stage PV inverter and a two-stage PV inverter...

  16. Performance evaluation of a 2-mode PV grid connected system in Thailand -- Case study

    Energy Technology Data Exchange (ETDEWEB)

    Jivacate, C.; Mongconvorawan, S.; Sinratanapukdee, E.; Limsawatt, W. [Electricity Generating Authority of Thailand, Nontha Buri (Thailand)

    1994-12-31

    A PV grid connected system with small battery bank has been set up in a rural district, North Thailand in order to demonstrate a 2-mode operation concept. The objective is to gain experience on the PV grid connected concept without battery storage. However, due to the evening peak demand and a rather weak distribution grid which is typical in rural areas, small battery bank is still required to enable the maximum energy transfer to grid for the time being before moving fully to the no battery mode. The analyzed data seems to indicate possible performance improvement by re-arranging the number of PV modules and battery in the string.

  17. HR Connect

    Data.gov (United States)

    US Agency for International Development — HR Connect is the USAID HR personnel system which allows HR professionals to process HR actions related to employee's personal and position information. This system...

  18. A New Power Calculation Method for Single-Phase Grid-Connected Systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede

    2013-01-01

    A new method to calculate average active power and reactive power for single-phase systems is proposed in this paper. It can be used in different applications where the output active power and reactive power need to be calculated accurately and fast. For example, a grid-connected photovoltaic...... system in low voltage ride through operation mode requires a power feedback for the power control loop. Commonly, a Discrete Fourier Transform (DFT) based power calculation method can be adopted in such systems. However, the DFT method introduces at least a one-cycle time delay. The new power calculation...... method, which is based on the adaptive filtering technique, can achieve a faster response. The performance of the proposed method is verified by experiments and demonstrated in a 1 kW single-phase grid-connected system operating under different conditions.Experimental results show the effectiveness...

  19. Connecting two jumplike unravelings for non-Markovian open quantum systems

    Energy Technology Data Exchange (ETDEWEB)

    Luoma, Kimmo; Suominen, Kalle-Antti; Piilo, Jyrki [Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turun Yliopisto (Finland)

    2011-09-15

    The development and use of Monte Carlo algorithms plays a visible role in the study of non-Markovian quantum dynamics due to the provided insight and powerful numerical methods for solving the system dynamics. In the Markovian case, the connections between the various types of methods are fairly well understood while, for the non-Markovian case, there has so far been only a few studies. We focus here on two jumplike unravelings of non-Markovian dynamics: the non-Markovian quantum jump (NMQJ) method and the property state method by Gambetta, Askerud, and Wiseman (GAW). The results for simple quantum optical systems illustrate the connections between the realizations of the two methods and also highlight how the probability currents between the system and environment, or between the property states of the total system, are associated with the decay rates of time-local master equations and, consequently, with the jump rates of the NMQJ method.

  20. Connecting two jumplike unravelings for non-Markovian open quantum systems

    International Nuclear Information System (INIS)

    Luoma, Kimmo; Suominen, Kalle-Antti; Piilo, Jyrki

    2011-01-01

    The development and use of Monte Carlo algorithms plays a visible role in the study of non-Markovian quantum dynamics due to the provided insight and powerful numerical methods for solving the system dynamics. In the Markovian case, the connections between the various types of methods are fairly well understood while, for the non-Markovian case, there has so far been only a few studies. We focus here on two jumplike unravelings of non-Markovian dynamics: the non-Markovian quantum jump (NMQJ) method and the property state method by Gambetta, Askerud, and Wiseman (GAW). The results for simple quantum optical systems illustrate the connections between the realizations of the two methods and also highlight how the probability currents between the system and environment, or between the property states of the total system, are associated with the decay rates of time-local master equations and, consequently, with the jump rates of the NMQJ method.

  1. Rendezvous with connectivity preservation for multi-robot systems with an unknown leader

    Science.gov (United States)

    Dong, Yi

    2018-02-01

    This paper studies the leader-following rendezvous problem with connectivity preservation for multi-agent systems composed of uncertain multi-robot systems subject to external disturbances and an unknown leader, both of which are generated by a so-called exosystem with parametric uncertainty. By combining internal model design, potential function technique and adaptive control, two distributed control strategies are proposed to maintain the connectivity of the communication network, to achieve the asymptotic tracking of all the followers to the output of the unknown leader system, as well as to reject unknown external disturbances. It is also worth to mention that the uncertain parameters in the multi-robot systems and exosystem are further allowed to belong to unknown and unbounded sets when applying the second fully distributed control law containing a dynamic gain inspired by high-gain adaptive control or self-tuning regulator.

  2. Fuzzy comprehensive evaluation for grid-connected performance of integrated distributed PV-ES systems

    Science.gov (United States)

    Lv, Z. H.; Li, Q.; Huang, R. W.; Liu, H. M.; Liu, D.

    2016-08-01

    Based on the discussion about topology structure of integrated distributed photovoltaic (PV) power generation system and energy storage (ES) in single or mixed type, this paper focuses on analyzing grid-connected performance of integrated distributed photovoltaic and energy storage (PV-ES) systems, and proposes a comprehensive evaluation index system. Then a multi-level fuzzy comprehensive evaluation method based on grey correlation degree is proposed, and the calculations for weight matrix and fuzzy matrix are presented step by step. Finally, a distributed integrated PV-ES power generation system connected to a 380 V low voltage distribution network is taken as the example, and some suggestions are made based on the evaluation results.

  3. Distributed Power System Virtual Inertia Implemented by Grid-Connected Power Converters

    DEFF Research Database (Denmark)

    Fang, Jingyang; Li, Hongchang; Tang, Yi

    2018-01-01

    Renewable energy sources (RESs), e.g. wind and solar photovoltaics, have been increasingly used to meet worldwide growing energy demands and reduce greenhouse gas emissions. However, RESs are normally coupled to the power grid through fast-response power converters without any inertia, leading...... to decreased power system inertia. As a result, the grid frequency may easily go beyond the acceptable range under severe frequency events, resulting in undesirable load-shedding, cascading failures, or even large-scale blackouts. To address the ever-decreasing inertia issue, this paper proposes the concept...... of distributed power system virtual inertia, which can be implemented by grid-connected power converters. Without modifications of system hardware, power system inertia can be emulated by the energy stored in the dc-link capacitors of grid-connected power converters. By regulating the dc-link voltages...

  4. Performance of a grid connected PV system used as active filter

    International Nuclear Information System (INIS)

    Calleja, Hugo; Jimenez, Humberto

    2004-01-01

    In this paper, the performance of a grid connected photovoltaic (PV) system used as an active filter is presented. Its main feature is the capability to compensate the reactive and harmonic currents drawn by nonlinear loads while simultaneously injecting into the grid the maximum power available from the cells. The system can also operate as a stand alone active filter. The system was connected to a 1 kW PV array and tested with the loads typically found in households: small motors, personal computers and electronic ballasts. The results show that the system can correct the power factor to values close to unity for all the cases tested, thereby improving the efficiency of the electric energy supply

  5. Elasticity of Relativistic Rigid Bodies?

    Science.gov (United States)

    Smarandache, Florentin

    2013-10-01

    In the classical Twin Paradox, according to the Special Theory of Relativity, when the traveling twin blasts off from the Earth to a relative velocity v =√{/3 } 2 c with respect to the Earth, his measuring stick and other physical objects in the direction of relative motion shrink to half their lengths. How is that possible in the real physical world to have let's say a rigid rocket shrinking to half and then later elongated back to normal as an elastic material when it stops? What is the explanation for the traveler's measuring stick and other physical objects, in effect, return to the same length to their original length in the Stay-At-Home, but there is no record of their having shrunk? If it's a rigid (not elastic) object, how can it shrink and then elongate back to normal? It might get broken in such situation.

  6. Functionally rigid bistable [2]rotaxanes

    DEFF Research Database (Denmark)

    Nygaard, Sune; Leung, Ken C-F; Aprahamian, Ivan

    2007-01-01

    defines an unambiguous distance of 1.5 nm over which the ring moves between the MPTTF and NP units. The degenerate NP/NP [2]rotaxane was used to investigate the shuttling barrier by dynamic 1H NMR spectroscopy for the movement of the CBPQT4+ ring across the new rigid spacer. It is evident from...... better control over the position of the ring component in the ground state but also for control over the location of the CBPQT4+ ring during solution-state switching experiments, triggered either chemically (1H NMR) or electrochemically (cyclic voltammetry). In this instance, the use of the rigid spacer......Two-station [2]rotaxanes in the shape of a degenerate naphthalene (NP) shuttle and a nondegenerate monopyrrolotetrathiafulvalene (MPTTF)/NP redox-controllable switch have been synthesized and characterized in solution. Their dumbbell-shaped components are composed of polyether chains interrupted...

  7. Associative memory through rigid origami

    Science.gov (United States)

    Murugan, Arvind; Brenner, Michael

    2015-03-01

    Mechanisms such as Miura Ori have proven useful in diverse contexts since they have only one degree of freedom that is easily controlled. We combine the theory of rigid origami and associative memory in frustrated neural networks to create structures that can ``learn'' multiple generic folding mechanisms and yet can be robustly controlled. We show that such rigid origami structures can ``recall'' a specific learned mechanism when induced by a physical impulse that only need resemble the desired mechanism (i.e. robust recall through association). Such associative memory in matter, seen before in self-assembly, arises due to a balance between local promiscuity (i.e., many local degrees of freedom) and global frustration which minimizes interference between different learned behaviors. Origami with associative memory can lead to a new class of deployable structures and kinetic architectures with multiple context-dependent behaviors.

  8. Rigidity spectrum of Forbush decrease

    International Nuclear Information System (INIS)

    Sakakibara, S.; Munakata, K.; Nagashima, K.

    1985-01-01

    Using data from neutron monitors and muon telescopes at surface and underground stations, the average rigidity spectrum of Forbush decreases (Fds) during the period of 1978-1982 were obtained. Thirty eight Ed-events are classified into two groups, Hard Fd and Soft FD according to size of Fd at the Sakashita station. It is found that a spectral form of a fractional-power type (P to the-gamma sub 1 (P+P sub c) to the -gamma sub2) is more suitable than that of a power-exponential type or of a power type with an upper limiting rigidity. The best fitted spectrum of the fractional-power type is expressed by gamma sub1 = 0.37, gamma sub2 = 0.89 and P subc = 10 GV for Hard Fd and gamma sub1 = 0.77, gamma sub2 = 1.02 and P sub c - 14GV for Soft Fd

  9. Abnormal systemic venous connection possibly associated with a persistent right umbilical vein; a case report

    Directory of Open Access Journals (Sweden)

    Smevik Bjarne

    2004-04-01

    Full Text Available Abstract Background Abnormal venous connections involving a persistent right umbilical vein are rare. In a minority of cases the liver is entirely bypassed and the condition is associated with multiple congenital malformations. Case presentation The described case illustrates a systemic venous drainage that was severely abnormal in a newborn girl with a truncus arteriosus type II congenital heart defect. Injection of contrast medium through the umbilical vein catheter revealed a very peculiar venous connection that passed anterio-laterally through the right hemithorax before crossing in an oblique fashion towards the superior vena cava. Conclusions This venous drainage may be the result of a persistent right umbilical vein connecting with the superior vena cava.

  10. The challenges of connecting generation to distribution systems: a utility perspective

    International Nuclear Information System (INIS)

    Kropp, F.

    2004-01-01

    'Full text:' This presentation discusses the technical, financial and regulatory barriers to connecting generation to Distribution Systems in Ontario. Case studies will be used to provide examples of the operational and technical challenges that impact the utility as well as a discussion on the site-specific advantages and disadvantages (to the utility) of the generation connections. These studies will include discussions on the problems and lessons learned with respect to the overall project implementation and the contractual agreements. The case studies will be complemented by an explanation of the financial constraints (both short term and long term) associated with the connections, and the regulatory issues that impact the financial recovery models including net and gross load billing. (author)

  11. Flexible Mode Control of Grid Connected Wind Energy Conversion System Using Wavelet

    Directory of Open Access Journals (Sweden)

    Bhavna Jain

    2015-01-01

    Full Text Available Small wind turbine systems offer services to critical loads during grid faults and also connected back to grid in normal condition. The connection of a wind energy conversion system to the grid requires a robust phase locked loop (PLL and continuous monitoring of the grid conditions such as overvoltage, undervoltage, overfrequency, underfrequency, and grid outages. This paper describes a flexible control operation to operate a small wind turbine in both stand-alone mode via planned islanding and grid connected mode as well. In particular, a proper monitoring and control algorithm is required for transition between the modes. A wavelet based energy function is used for detection of grid disturbances as well as recovery of grid so that transition between the modes is made. To obtain good power quality LCL filter is used to reduce ripples. PLL is used for synchronization whenever mode changes from stand-alone to grid connected. Simulation results from a 10 kW wind energy conversion system are included to show the usefulness of the proposed methods. The control method is tested by generated gate pulses for single phase bridge inverter using field programmable gate array (FPGA.

  12. Avalanching Systems with Longer Range Connectivity: Occurrence of a Crossover Phenomenon and Multifractal Finite Size Scaling

    Directory of Open Access Journals (Sweden)

    Simone Benella

    2017-07-01

    Full Text Available Many out-of-equilibrium systems respond to external driving with nonlinear and self-similar dynamics. This near scale-invariant behavior of relaxation events has been modeled through sand pile cellular automata. However, a common feature of these models is the assumption of a local connectivity, while in many real systems, we have evidence for longer range connectivity and a complex topology of the interacting structures. Here, we investigate the role that longer range connectivity might play in near scale-invariant systems, by analyzing the results of a sand pile cellular automaton model on a Newman–Watts network. The analysis clearly indicates the occurrence of a crossover phenomenon in the statistics of the relaxation events as a function of the percentage of longer range links and the breaking of the simple Finite Size Scaling (FSS. The more complex nature of the dynamics in the presence of long-range connectivity is investigated in terms of multi-scaling features and analyzed by the Rank-Ordered Multifractal Analysis (ROMA.

  13. Marketing residential grid-connected PV systems using a balanced scorecard as a marketing tool

    International Nuclear Information System (INIS)

    Bach, N.; Calais, P.; Calais, M.

    2001-01-01

    A strategic analysis of the electricity market in Western Australia yields a market potential for renewable energy in Western Australia. However, from a purely financial viewpoint the installation of grid-connected pv-systems still is not economically viable. In this paper a balanced scorecard (BSC) is developed to capture and visualize other than financial benefits. Therefore, the BSC can be used as a marketing tool to communicate the benefits of a privately owned GCPV system to potential customers. (author)

  14. Accelerated Monte Carlo system reliability analysis through machine-learning-based surrogate models of network connectivity

    International Nuclear Information System (INIS)

    Stern, R.E.; Song, J.; Work, D.B.

    2017-01-01

    The two-terminal reliability problem in system reliability analysis is known to be computationally intractable for large infrastructure graphs. Monte Carlo techniques can estimate the probability of a disconnection between two points in a network by selecting a representative sample of network component failure realizations and determining the source-terminal connectivity of each realization. To reduce the runtime required for the Monte Carlo approximation, this article proposes an approximate framework in which the connectivity check of each sample is estimated using a machine-learning-based classifier. The framework is implemented using both a support vector machine (SVM) and a logistic regression based surrogate model. Numerical experiments are performed on the California gas distribution network using the epicenter and magnitude of the 1989 Loma Prieta earthquake as well as randomly-generated earthquakes. It is shown that the SVM and logistic regression surrogate models are able to predict network connectivity with accuracies of 99% for both methods, and are 1–2 orders of magnitude faster than using a Monte Carlo method with an exact connectivity check. - Highlights: • Surrogate models of network connectivity are developed by machine-learning algorithms. • Developed surrogate models can reduce the runtime required for Monte Carlo simulations. • Support vector machine and logistic regressions are employed to develop surrogate models. • Numerical example of California gas distribution network demonstrate the proposed approach. • The developed models have accuracies 99%, and are 1–2 orders of magnitude faster than MCS.

  15. Torsional rigidity, isospectrality and quantum graphs

    International Nuclear Information System (INIS)

    Colladay, Don; McDonald, Patrick; Kaganovskiy, Leon

    2017-01-01

    We study torsional rigidity for graph and quantum graph analogs of well-known pairs of isospectral non-isometric planar domains. We prove that such isospectral pairs are distinguished by torsional rigidity. (paper)

  16. The Newcastle connection: A software subsystem for constructing distributed UNIX systems

    International Nuclear Information System (INIS)

    Randell, B.

    1985-01-01

    The Newcastle connection is a software subsystem that can be added to each of a set of physically interconnected UNIX or UNIX look-alike systems, so as to construct a distributed system which is functionally indistinguishable at both the user and the program level from a conventional single-processor UNIX system. The techniques used are applicable to a variety and multiplicity of both local and wide area networks, and enable all issues of inter-processor communication, network protocols, etc., to be hidden. A brief account is given of experience with such distributed systems, the first of which was constructed in 1982 using a set of PDP11s running UNIX Version 7, and connected by a Cambridge Ring - since this date the Connection has been used to construct distributed systems based on various other computers and versions of UNIX, both at Newcastle and elsewhere. The final sections compare our scheme to various precursor schemes and discuss its potential relevance to other operating systems. (orig.)

  17. Connecting section and associated systems concept for the spray calciner/in-can melter process

    International Nuclear Information System (INIS)

    Petkus, L.L.; Gorton, P.S.; Blair, H.T.

    1981-06-01

    For a number of years, researchers at the Pacific Northwest Laboratory have been developing processes and equipment for converting high-level liquid wastes to solid forms. One of these processes is the Spray Calciner/In-Can Melter system. To immobilize high-level liquid wastes, this system must be operated remotely, and the calcine must be reliably conveyed from the calciner to the melting furnace. A concept for such a remote conveyance system was developed at the Pacific Northwest Laboratory, and equipment was tested under full-scale, nonradioactive conditions. This concept and the design of demonstration equipment are described, and the results of equipment operation during experimental runs of 7 d are presented. The design includes a connecting section and its associated systems - a canister sypport and alignment concept and a weight-monitoring system for the melting furnace. Overall, the runs demonstrated that the concept design is an acceptable method of connecting the two pieces of process equipment together. Although the connecting section has not been optimized in all areas of concern, it provides a first-generation design of a production-oriented system

  18. Experimental evaluation of 8 kW grid-connected photovoltaic system in Egypt

    Directory of Open Access Journals (Sweden)

    A. Elkholy

    2016-09-01

    Full Text Available An experimental observation study of 8 kW grid-connected photovoltaic (PV system that is installed at Electronics Research Institute (ERI, Giza, Egypt (Latitude 30.04°N, Longitude 31.21°E, is presented. This study includes the quality of the electrical power generated and injected into the network. The considered system consists of 28 × 295 Wp multicrystalline PV modules, StecaGrid three-phase 8 kW grid-connected inverter and a Solar-Log 300 PM+ for data acquisition and remote monitoring. The power quality parameters at the inverter output side have been measured using CA8335 power quality analyzer. The system has been installed in August 2014 and generated 5.7 MWh till February 2015. The produced electricity by the system is injected directly into the grid without storage device. The purpose of this paper is to present and evaluate the measurements of the power quality parameters obtained from the PV site. Also, this paper presents a comprehensive evaluation of the performance of the system over a period of one week. The observation and analyses exploitation of the collected data can help to evaluate the performance of the PV system connected to the network.

  19. Singular solutions for the rigid plastic double slip and rotation model under plane strain

    Science.gov (United States)

    Alexandrov, S.; Lyamina, E.

    2018-02-01

    In the mechanics of granular and other materials the system of equations comprising the rigid plastic double slip and rotation model together with the stress equilibrium equations under plane strain conditions forms a hyperbolic system. Boundary value problems for this system of equations can involve a frictional interface. An envelope of characteristics may coincide with this interface. In this case, the solution is singular. In particular, some components of the strain rate tensor approach infinity in the vicinity of the frictional interface. Such behavior of solutions is in qualitative agreement with experimental data that show that a narrow layer of localized plastic deformation is often generated near frictional interfaces. The present paper deals with asymptotic analysis of the aforementioned system of equations in the vicinity of an envelope of characteristics. It is shown that the shear strain rate and the spin component in a local coordinate system connected to the envelope follow an inverse square root rule in its vicinity.

  20. The implantation of a grid-connected PV system at CEPEL

    Energy Technology Data Exchange (ETDEWEB)

    Galdino, Marco Antonio, E-mail: marcoag@cepel.br

    2003-07-01

    This technical report presents the experience undertaken by CEPEL for implantation of a grid connected PV system at its headquarters, located in Rio de Janeiro, RJ, Brazil. This technology, although considered far from Brazilian reach, is expected to grow significantly in the near future. The paper describes briefly several aspects concerning the PV system and the DAS (data acquisition system) implemented in order to allow the continuous evaluation of its performance and operational conditions. The system was installed in December, 2002, and the data are still preliminary. (author)

  1. A new learning algorithm for a fully connected neuro-fuzzy inference system.

    Science.gov (United States)

    Chen, C L Philip; Wang, Jing; Wang, Chi-Hsu; Chen, Long

    2014-10-01

    A traditional neuro-fuzzy system is transformed into an equivalent fully connected three layer neural network (NN), namely, the fully connected neuro-fuzzy inference systems (F-CONFIS). The F-CONFIS differs from traditional NNs by its dependent and repeated weights between input and hidden layers and can be considered as the variation of a kind of multilayer NN. Therefore, an efficient learning algorithm for the F-CONFIS to cope these repeated weights is derived. Furthermore, a dynamic learning rate is proposed for neuro-fuzzy systems via F-CONFIS where both premise (hidden) and consequent portions are considered. Several simulation results indicate that the proposed approach achieves much better accuracy and fast convergence.

  2. Two-stage single-phase grid-connected photovoltaic system with reduced complexity

    Science.gov (United States)

    da Silva, Cintia S.; Motta, Filipe R.; Tofoli, Fernando L.

    2011-06-01

    This article presents a grid-connected photovoltaic (PV) system using the classical DC-DC buck converter, which is responsible for stepping down the resulting voltage from several series-connected panels. Besides, the structure provides high power factor operation by injecting a quasi-sinusoidal current into the grid, with near no displacement in relation to the line voltage at the point of common coupling among the PV system and the loads. A CSI employing thyristors is cascaded with the DC-DC stage so that AC voltage results. The inverter output voltage level is adjusted by using a low-frequency transformer, which also provides galvanic isolation. The proposed system is described as mathematical approach and design guidelines are presented, providing an overview of the topology. An experimental prototype is also implemented, and relevant results to validate the proposal are discussed.

  3. Modified Grid-Connected CSI for Hybrid PV/Wind Power Generation System

    Directory of Open Access Journals (Sweden)

    D. Amorndechaphon

    2012-01-01

    Full Text Available The principle of a power conditioning unit for hybrid PV/wind power generation system is proposed. The proposed power conditioner is based on the current source inverter (CSI topology. All energy sources are connected in parallel with a DC-bus through the modified wave-shaping circuits. To achieve the unity power factor at the utility grid, the DC-link current can be controlled via the wave-shaping circuits with the sinusoidal PWM scheme. In this work, the carrier-based PWM scheme is also proposed to minimize the utility current THD. The power rating of the proposed system can be increased by connecting more PV/wind modules through their wave-shaping circuits in parallel with the other modules. The details of the operating principles, the system configurations, and the design considerations are described. The effectiveness of the proposed CSI is demonstrated by simulation results.

  4. Grid-connected vehicles as the core of future land-based transport systems

    International Nuclear Information System (INIS)

    Gilbert, Richard; Perl, Anthony

    2007-01-01

    Grid-connected vehicles (GCVs)-e.g., electric trains, metros, trams, and trolley buses-are propelled by electric motors directly connected to remote power sources. Their low at-vehicle energy consumption and ability to use a wide range of renewable energy sources make them strong contenders for urban and interurban transport systems in an era of energy constraints that favours use of renewable fuels, which may lie ahead. Needs for autonomous motorised mobility could be acceptably met in large measure by deployment of personal GCVs, also known as personal rapid transit (PRT). Alternatives, including fuel-cell vehicles and dual-drive vehicles fuelled with ethanol, will be less feasible. The 'car of the future' may not be an automobile so much as a PRT element of a comprehensive GCV-based system that offers at least as much utility and convenience as today's transport systems

  5. OpenID connect as a security service in Cloud-based diagnostic imaging systems

    Science.gov (United States)

    Ma, Weina; Sartipi, Kamran; Sharghi, Hassan; Koff, David; Bak, Peter

    2015-03-01

    The evolution of cloud computing is driving the next generation of diagnostic imaging (DI) systems. Cloud-based DI systems are able to deliver better services to patients without constraining to their own physical facilities. However, privacy and security concerns have been consistently regarded as the major obstacle for adoption of cloud computing by healthcare domains. Furthermore, traditional computing models and interfaces employed by DI systems are not ready for accessing diagnostic images through mobile devices. RESTful is an ideal technology for provisioning both mobile services and cloud computing. OpenID Connect, combining OpenID and OAuth together, is an emerging REST-based federated identity solution. It is one of the most perspective open standards to potentially become the de-facto standard for securing cloud computing and mobile applications, which has ever been regarded as "Kerberos of Cloud". We introduce OpenID Connect as an identity and authentication service in cloud-based DI systems and propose enhancements that allow for incorporating this technology within distributed enterprise environment. The objective of this study is to offer solutions for secure radiology image sharing among DI-r (Diagnostic Imaging Repository) and heterogeneous PACS (Picture Archiving and Communication Systems) as well as mobile clients in the cloud ecosystem. Through using OpenID Connect as an open-source identity and authentication service, deploying DI-r and PACS to private or community clouds should obtain equivalent security level to traditional computing model.

  6. Performance of Grid-Connected Photovoltaic System in Two Sites in Kuwait

    Directory of Open Access Journals (Sweden)

    Ali Hajiah

    2012-01-01

    Full Text Available This paper presents an assessment of the electricity generated by photovoltaic (PV grid-connected systems in Kuwait. Three years of meteorological data are provided for two main sites in Kuwait, namely, Al-Wafra and Mutla. These data and a PV grid-connected system mathematical model are used to assist a 100 kWp grid-connected PV system proposed for both sites. The proposed systems show high energy productivity whereas the annual capacity factors for Mutla and Al-Wafra are 22.25% and 21.6%, respectively. Meanwhile the annual yield factors for Mutla and Al-Wafra are 1861 kWh/kWp/year and 1922.7 kWh/kWp/year, respectively. On the other hand the cost of the energy generated by both systems is about 0.1 USD/kWh which is very close to the price of the energy sold by the Ministry of Electricity and Water (MEW. Furthermore the invested money is recovered during the assumed life cycle time whereas the payback period for both sites is about 15 years. This work contains worthwhile technical information for those who are interested in PV technology investment in Kuwait.

  7. Design of a Solar Motor Drive System Fed by a Direct-Connected Photovoltaic Array

    Directory of Open Access Journals (Sweden)

    AYDOGMUS, O.

    2012-08-01

    Full Text Available A solar motor pump drive system is modeled and simulated. The proposed drive system does not require any kind of energy storage system and dc-dc converter. The system is connected directly to a photovoltaic (PV array. Thus, a low cost solar system can be achieved. A vector controlled Permanent Magnet Synchronous Motor (PMSM is used as a solar motor to increase the efficiency of system. The motor is designed for a low rated voltage level about 24V. The hill climbing MPPT method is used for balanced the motor power and PV power to obtain a high efficiency. The results are performed by using MATLAB/SimPowerSystem blocks. In addition, the PV array is modeled to allow for the possibility of running as on-line adjustable in simulation environment without using lookup table. The performances of motor, MPPT and drive system are analyzed in different conditions as temperature and irradiation of PV array.

  8. Active and reactive power neurocontroller for grid-connected photovoltaic generation system

    Directory of Open Access Journals (Sweden)

    I. Abadlia

    2016-03-01

    Full Text Available Many researchers have contributed to the development of a firm foundation for analysis and design of control applications in grid-connected renewable energy sources. This paper presents an intelligent control algorithm fond on artificial neural networks for active and reactive power controller in grid-connected photovoltaic generation system. The system is devices into two parts in which each part contains an inverter with control algorithm. A DC/DC converter in output voltage established by control magnitude besides maximum power point tracker algorithm always finds optimal power of the PV array in use. A DC/AC hysteresis inverter designed can synchronize a sinusoidal current output with the grid voltage and accurate an independent active and reactive power control. Simulation results confirm the validation of the purpose. Neurocontroller based active and reactive power presents an efficiency control that guarantees good response to the steps changing in active and reactive power with an acceptable current/voltage synchronism. In this paper the power circuit and the control system of the presented grid-connected photovoltaic generation system is simulated and tested by MatLab/Simulink.

  9. Network connectivity and individual responses to brain stimulation in the human motor system.

    Science.gov (United States)

    Cárdenas-Morales, Lizbeth; Volz, Lukas J; Michely, Jochen; Rehme, Anne K; Pool, Eva-Maria; Nettekoven, Charlotte; Eickhoff, Simon B; Fink, Gereon R; Grefkes, Christian

    2014-07-01

    The mechanisms driving cortical plasticity in response to brain stimulation are still incompletely understood. We here explored whether neural activity and connectivity in the motor system relate to the magnitude of cortical plasticity induced by repetitive transcranial magnetic stimulation (rTMS). Twelve right-handed volunteers underwent functional magnetic resonance imaging during rest and while performing a simple hand motor task. Resting-state functional connectivity, task-induced activation, and task-related effective connectivity were assessed for a network of key motor areas. We then investigated the effects of intermittent theta-burst stimulation (iTBS) on motor-evoked potentials (MEP) for up to 25 min after stimulation over left primary motor cortex (M1) or parieto-occipital vertex (for control). ITBS-induced increases in MEP amplitudes correlated negatively with movement-related fMRI activity in left M1. Control iTBS had no effect on M1 excitability. Subjects with better response to M1-iTBS featured stronger preinterventional effective connectivity between left premotor areas and left M1. In contrast, resting-state connectivity did not predict iTBS aftereffects. Plasticity-related changes in M1 following brain stimulation seem to depend not only on local factors but also on interconnected brain regions. Predominantly activity-dependent properties of the cortical motor system are indicative of excitability changes following induction of cortical plasticity with rTMS. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  10. IoT Architectural Framework: Connection and Integration Framework for IoT Systems

    OpenAIRE

    Uviase, Onoriode; Kotonya, Gerald

    2018-01-01

    The proliferation of the Internet of Things (IoT) has since seen a growing interest in architectural design and adaptive frameworks to promote the connection between heterogeneous IoT devices and IoT systems. The most widely favoured software architecture in IoT is the Service Oriented Architecture (SOA), which aims to provide a loosely coupled systems to leverage the use and reuse of IoT services at the middle-ware layer, to minimise system integration problems. However, despite the flexibil...

  11. Compensated Row-Column Ultrasound Imaging System Using Multilayered Edge Guided Stochastically Fully Connected Random Fields.

    Science.gov (United States)

    Ben Daya, Ibrahim; Chen, Albert I H; Shafiee, Mohammad Javad; Wong, Alexander; Yeow, John T W

    2017-09-06

    The row-column method received a lot of attention for 3-D ultrasound imaging. By reducing the number of connections required to address the 2-D array and therefore reducing the amount of data to handle, this addressing method allows for real time 3-D imaging. Row-column still has its limitations: the issues of sparsity, speckle noise inherent to ultrasound, the spatially varying point spread function, and the ghosting artifacts inherent to the row-column method must all be taken into account when building a reconstruction framework. In this research, we build on a previously published system and propose an edge-guided, compensated row-column ultrasound imaging system that incorporates multilayered edge-guided stochastically fully connected conditional random fields to address the limitations of the row-column method. Tests carried out on simulated and real row-column ultrasound images show the effectiveness of our proposed system over other published systems. Visual assessment show our proposed system's potential at preserving edges and reducing speckle. Quantitative analysis shows that our proposed system outperforms previously published systems when evaluated with metrics such as Peak Signal-to-Noise Ratio, Coefficient of Correlation, and Effective Number of Looks. These results show the potential of our proposed system as an effective tool for enhancing 3-D row-column imaging.

  12. Zero-Voltage Ride-Through Capability of Single-Phase Grid-Connected Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Zhen Zhang

    2017-03-01

    Full Text Available Distributed renewable energy systems play an increasing role in today’s energy paradigm. Thus, intensive research activities have been centered on improving the performance of renewable energy systems, including photovoltaic (PV systems, which should be of multiple-functionality. That is, the PV systems should be more intelligent in the consideration of grid stability, reliability, and fault protection. Therefore, in this paper, the performance of single-phase grid-connected PV systems under an extreme grid fault (i.e., when the grid voltage dips to zero is explored. It has been revealed that combining a fast and accurate synchronization mechanism with appropriate control strategies for the zero-voltage ride-through (ZVRT operation is mandatory. Accordingly, the representative synchronization techniques (i.e., the phase-locked loop (PLL methods in the ZVRT operation are compared in terms of detection precision and dynamic response. It shows that the second-order generalized integrator (SOGI-PLL is a promising solution for single-phase systems in the case of fault ride-through. A control strategy by modifying the SOGI-PLL scheme is then introduced to single-phase grid-connected PV systems for ZVRT operation. Simulations are performed to verify the discussions. The results have demonstrated that the proposed method can help single-phase PV systems to temporarily ride through zero-voltage faults with good dynamics.

  13. Sensorless Reserved Power Control Strategy for Two-Stage Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2016-01-01

    Due to still increasing penetration level of grid-connected Photovoltaic (PV) systems, advanced active power control functionalities have been introduced in grid regulations. A reserved power control, where the active power from the PV panels is reserved during operation, is required for grid...... support. In this paper, a cost-effective solution to realize the reserved power control for grid-connected PV systems is proposed. The proposed solution routinely employs a Maximum Power Point Tracking (MPPT) control to estimate the available PV power and a Constant Power Generation (CPG) control...... to achieve the power reserve. In this method, the irradiance measurements that have been used in conventional control schemes to estimate the available PV power are not required, and thereby being a sensorless solution. Simulations and experimental tests have been performed on a 3-kW two-stage single...

  14. A techno-economic assessment of grid connected photovoltaic system for hospital building in Malaysia

    Science.gov (United States)

    Mat Isa, Normazlina; Tan, Chee Wei; Yatim, AHM

    2017-07-01

    Conventionally, electricity in hospital building are supplied by the utility grid which uses mix fuel including coal and gas. Due to enhancement in renewable technology, many building shall moving forward to install their own PV panel along with the grid to employ the advantages of the renewable energy. This paper present an analysis of grid connected photovoltaic (GCPV) system for hospital building in Malaysia. A discussion is emphasized on the economic analysis based on Levelized Cost of Energy (LCOE) and total Net Present Post (TNPC) in regards with the annual interest rate. The analysis is performed using Hybrid Optimization Model for Electric Renewables (HOMER) software which give optimization and sensitivity analysis result. An optimization result followed by the sensitivity analysis also being discuss in this article thus the impact of the grid connected PV system has be evaluated. In addition, the benefit from Net Metering (NeM) mechanism also discussed.

  15. International comparison of requirements for connection of wind turbines to power systems

    Energy Technology Data Exchange (ETDEWEB)

    Jauch, C. [Risoe National Lab., Roskilde (Denmark). Dept. of Wind Energy; Matevosyan, J.; Ackermann, T. [Royal Inst. of Technology, Stockholm (Sweden). Dept. of Electrical Engineering; Bolik, S. [Vestas Wind Systems A/S, Ringkoebing (Denmark)

    2005-07-01

    Power production from wind turbines has increased considerably during the last decade. Therefore today's wind turbines, which are typically set up in wind farms, have a significant influence on the operation of power systems. The efficient and secure operation of power systems is supported by grid codes, which are sets of requirements for all network users (suppliers, customers, etc.). In Europe, several transmission network operators have introduced special grid connection requirements for wind farms. These requirements are mainly based on existing grid codes, initially written for conventional power plants usually equipped with synchronous generators. This article presents a comparison of grid connection requirements for wind farms issued, or proposed as a draft, by transmission network operators in Denmark, Sweden, Germany, Scotland and Ireland. (author)

  16. Progress in markets for grid-connected PV systems in the built environment

    International Nuclear Information System (INIS)

    Haas, R.

    2004-01-01

    In the last decade of the twentieth century a wide variety of promotion strategies increased the market penetration of small grid-connected PV systems world-wide. The objective of this paper is to assess the impact of these promotion strategies on the market for and on the economic performance of small grid-connected PV systems. The most important conclusions of this analysis are: Pure cost-effectiveness is not crucial for private customers. Affordability is rather what counts. Non-monetary issues play an important role for a substantial increase in market deployment. Comprehensive accompanied information and education activities are also important along with financial incentives. There are still considerable barriers in the market: on the one hand transparent and competitive markets exist in only a few countries; on the other hand non-monetary transaction costs still represent a major barrier. Progress with respect to cost reduction has been achieved, but mainly for non-module components. (author)

  17. Characteristic Analysis of DC Electric Railway Systems with Superconducting Power Cables Connecting Power Substations

    Science.gov (United States)

    Ohsaki, H.; Matsushita, N.; Koseki, T.; Tomita, M.

    2014-05-01

    The application of superconducting power cables to DC electric railway systems has been studied. It could leads to an effective use of regenerative brake, improved energy efficiency, effective load sharing among the substations, etc. In this study, an electric circuit model of a DC feeding system is built and numerical simulation is carried out using MATLAB-Simulink software. A modified electric circuit model with an AC power grid connection taken into account is also created to simulate the influence of the grid connection. The analyses have proved that a certain amount of energy can be conserved by introducing superconducting cables, and that electric load distribution and concentration among the substations depend on the substation output voltage distribution.

  18. Characteristic analysis of DC electric railway systems with superconducting power cables connecting power substations

    International Nuclear Information System (INIS)

    Ohsaki, H; Matsushita, N; Koseki, T; Tomita, M

    2014-01-01

    The application of superconducting power cables to DC electric railway systems has been studied. It could leads to an effective use of regenerative brake, improved energy efficiency, effective load sharing among the substations, etc. In this study, an electric circuit model of a DC feeding system is built and numerical simulation is carried out using MATLAB-Simulink software. A modified electric circuit model with an AC power grid connection taken into account is also created to simulate the influence of the grid connection. The analyses have proved that a certain amount of energy can be conserved by introducing superconducting cables, and that electric load distribution and concentration among the substations depend on the substation output voltage distribution.

  19. Harmonics Suppression for Single-Phase Grid-Connected Photovoltaic Systems in Different Operation Modes

    DEFF Research Database (Denmark)

    Yang, Yongheng; Zhou, Keliang; Blaabjerg, Frede

    2013-01-01

    -connected PV inverters may be severely affected in different operation modes. In this paper, a detailed analysis is conducted to reveal the relationship between the harmonics level with the power factor and the current level in the PV systems. A current control solution which employs an Internal Model...... Principle (IMP) is proposed to suppress the harmonic currents injected into the grid. Experiments are carried out to verify the analysis and the performance of the proposed control method. It is demonstrated that the proposed method presents an effective solution to harmonics suppression for single......-phase grid-connected PV systems in different operation modes. Especially, it can remove higher order harmonics effectively leading to a better power quality compared to the Proportional plus Multi-Resonant Controller, and it has less computational burden....

  20. Geometry, rigidity, and group actions

    CERN Document Server

    Farb, Benson; Zimmer, Robert J

    2011-01-01

    The study of group actions is more than a hundred years old but remains to this day a vibrant and widely studied topic in a variety of mathematic fields. A central development in the last fifty years is the phenomenon of rigidity, whereby one can classify actions of certain groups, such as lattices in semi-simple Lie groups. This provides a way to classify all possible symmetries of important spaces and all spaces admitting given symmetries. Paradigmatic results can be found in the seminal work of George Mostow, Gergory Margulis, and Robert J. Zimmer, among others.The p

  1. Parallel connecting poloidal coil system for a doublet tokamak fusion reactor

    International Nuclear Information System (INIS)

    Toffolo, W.E.; Chen, W.Y.; Purcell, J.R.; Wesley, J.C.

    1977-09-01

    A method has been developed for parallel connection of the ohmic heating (OH) coil. The method involves subdividing the OH-coil into a number of parallel connected subcoils, with each subcoil having about 20 turns. Each of the field shaping coils (F-coils) also contains 20 turns, so that when connected to a common power supply, the OH and F-coils are decoupled. The advantages resulting from the scheme are numerous: (1) each F-coil contains a much smaller number of turns compared with the previous design concept, thus the construction and maintenance will be easier; (2) the parallel connected OH-coils form a constant flux envelope, resulting in an inherently lower error field at the plasma and the TF coil region, and this low error field is not sensitive to the variation in location of the OH-coils; (3) the voltage and current ratings of the individual OH coil conductors are reduced; and (4) the low impedance of the OH-coil system greatly improves the possibility of using a homopolar motor generator as a means of achieving flux reversal during startup and plasma current control during the burn cycle

  2. OpenID Connect as a security service in cloud-based medical imaging systems.

    Science.gov (United States)

    Ma, Weina; Sartipi, Kamran; Sharghigoorabi, Hassan; Koff, David; Bak, Peter

    2016-04-01

    The evolution of cloud computing is driving the next generation of medical imaging systems. However, privacy and security concerns have been consistently regarded as the major obstacles for adoption of cloud computing by healthcare domains. OpenID Connect, combining OpenID and OAuth together, is an emerging representational state transfer-based federated identity solution. It is one of the most adopted open standards to potentially become the de facto standard for securing cloud computing and mobile applications, which is also regarded as "Kerberos of cloud." We introduce OpenID Connect as an authentication and authorization service in cloud-based diagnostic imaging (DI) systems, and propose enhancements that allow for incorporating this technology within distributed enterprise environments. The objective of this study is to offer solutions for secure sharing of medical images among diagnostic imaging repository (DI-r) and heterogeneous picture archiving and communication systems (PACS) as well as Web-based and mobile clients in the cloud ecosystem. The main objective is to use OpenID Connect open-source single sign-on and authorization service and in a user-centric manner, while deploying DI-r and PACS to private or community clouds should provide equivalent security levels to traditional computing model.

  3. Photovoltaic system connected to electric grid in Brazil; Sistemas fotovoltaicos conectados a rede eletrica no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Varella, Fabiana Karla de Oliveira Martins [Universidade Federal Rural do Semi-Arido (UFERSA), Mossoro, RN (Brazil)], email: fkv@ufersa.edu.br; Gomes, Rodolfo Dourado Maia; Jannuzzi, Gilberto De Martino [International Energy Initiative (IEI), Campinas, SP (Brazil)], email: rodolfo@iei-la.org

    2010-07-01

    Brazil has in the next decades the big challenge of seeking for solutions to meet its growing energy service needs and, at the same time, satisfy criteria of economics, security of supply, public health, secure universal energy access and environmental sustainability. The growing environmental pressures over the hydropower potential exploitation at the Amazon region and the energy sources even more distant from the customer load center are some of the aspects which are posed in order to seek for solutions. Several countries are betting on grid-connected PV systems. In Brazil, the initiatives to promote the use of PV energy are still a few. Even though the country is endowed with a great solar energy potential, the initiatives to create and consolidate a market for the use of such technology and to develop the national industry for equipment and services are still incipient. The lack of legislation and regulation is one of the barriers pointed out. Thus, the objective of this report is to assess the reasons why the country does not have a specific legislation to promote the use of grid-connected PV systems. For such, grid-connected PV systems installed in Brazil and the existent incentives are identified. The methodology used was based on literature review and conduction of specific questionnaires. The latter was sent to the Ministry of Mines and Energy, researchers and one power distribution company. (author)

  4. Analysis of grid connected solar PV system in the Southeastern Part of Bangladesh

    International Nuclear Information System (INIS)

    Ariful Islam; Fatema Akther Shima; Akhera Khanam

    2013-01-01

    Bangladesh is a potential site of implementing renewable energy system to reduce the severe power crisis throughout the year. According to this, Chittagong is the southeastern part of Bangladesh is also a potential site for implementing renewable energy system such as grid-connected photovoltaic (PV) system. Financial viability and green-house gas emission reduction of solar PV as an electricity generation source are assessed for 500 kW grid connected solar PV system at University of Chittagong, Chittagong. Homer simulation soft-ware and monthly average solar radiation data from NASA is used for this task. In the proposed system monthly electricity generation varies between 82.65 MW h and 60.3 MW h throughout the year with a mean value of 68.25 MW h depending on the monthly highest and lowest solar radiation data. It is found that per unit electricity production cost is US$ 0.20 based on project lifetime 25 years. The IRR, equity payback and benefit-cost ratio shows favorable condition for development of the proposed solar PV system in this site. A minimum 664 tones of green-house gas emissions can be reduced annually utilizing the proposed system. (authors)

  5. Evaluation of an automated connective tissue disease screening assay in Korean patients with systemic rheumatic diseases.

    Directory of Open Access Journals (Sweden)

    Seri Jeong

    Full Text Available This study aimed to evaluate the diagnostic utilities of the automated connective tissues disease screening assay, CTD screen, in patients with systemic rheumatic diseases. A total of 1093 serum samples were assayed using CTD screen and indirect immunofluorescent (IIF methods. Among them, 162 were diagnosed with systemic rheumatic disease, including rheumatoid arthritis (RA, systemic lupus erythematosus (SLE, and mixed connective tissue disease (MCT. The remaining 931 with non-systemic rheumatic disease were assigned to the control group. The median ratios of CTD screen tests were significantly higher in the systemic rheumatic disease group than in the control group. The positive likelihood ratios of the CTD screen were higher than those of IIF in patients with total rheumatic diseases (4.1 vs. 1.6, including SLE (24.3 vs. 10.7. The areas under the receiver operating characteristic curves (ROC-AUCs of the CTD screen for discriminating total rheumatic diseases, RA, SLE, and MCT from controls were 0.68, 0.56, 0.92 and 0.80, respectively. The ROC-AUCs of the combinations with IIF were significantly higher in patients with total rheumatic diseases (0.72 and MCT (0.85 than in those of the CTD screen alone. Multivariate analysis indicated that both the CTD screen and IIF were independent variables for predicting systemic rheumatic disease. CTD screen alone and in combination with IIF were a valuable diagnostic tool for predicting systemic rheumatic diseases, particularly for SLE.

  6. New current control based MPPT technique for single stage grid connected PV systems

    International Nuclear Information System (INIS)

    Jain, Sachin; Agarwal, Vivek

    2007-01-01

    This paper presents a new maximum power point tracking algorithm based on current control for a single stage grid connected photovoltaic system. The main advantage of this algorithm comes from its ability to predict the approximate amplitude of the reference current waveform or power that can be derived from the PV array with the help of an intermediate variable β. A variable step size for the change in reference amplitude during initial tracking helps in fast tracking. It is observed that if the reference current amplitude is greater than the array capacity, the system gets unstable (i.e. moves into the positive slope region of the p-v characteristics of the array). The proposed algorithm prevents the PV system from entering the positive slope region of the p-v characteristics. It is also capable of restoring stability if the system goes unstable due to a sudden environmental change. The proposed algorithm has been tested on a new single stage grid connected PV configuration recently developed by the authors to feed sinusoidal current into the grid. The system is operated in a continuous conduction mode to realize advantages such as low device current stress, high efficiency and low EMI. A fast MPPT tracker with single stage inverter topology operating in CCM makes the overall system highly efficient. Specific cases of the system, operating in just discontinuous current mode and discontinuous current mode and their relative merits and demerits are also discussed

  7. Evaluation of an automated connective tissue disease screening assay in Korean patients with systemic rheumatic diseases.

    Science.gov (United States)

    Jeong, Seri; Yang, Heeyoung; Hwang, Hyunyong

    2017-01-01

    This study aimed to evaluate the diagnostic utilities of the automated connective tissues disease screening assay, CTD screen, in patients with systemic rheumatic diseases. A total of 1093 serum samples were assayed using CTD screen and indirect immunofluorescent (IIF) methods. Among them, 162 were diagnosed with systemic rheumatic disease, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and mixed connective tissue disease (MCT). The remaining 931 with non-systemic rheumatic disease were assigned to the control group. The median ratios of CTD screen tests were significantly higher in the systemic rheumatic disease group than in the control group. The positive likelihood ratios of the CTD screen were higher than those of IIF in patients with total rheumatic diseases (4.1 vs. 1.6), including SLE (24.3 vs. 10.7). The areas under the receiver operating characteristic curves (ROC-AUCs) of the CTD screen for discriminating total rheumatic diseases, RA, SLE, and MCT from controls were 0.68, 0.56, 0.92 and 0.80, respectively. The ROC-AUCs of the combinations with IIF were significantly higher in patients with total rheumatic diseases (0.72) and MCT (0.85) than in those of the CTD screen alone. Multivariate analysis indicated that both the CTD screen and IIF were independent variables for predicting systemic rheumatic disease. CTD screen alone and in combination with IIF were a valuable diagnostic tool for predicting systemic rheumatic diseases, particularly for SLE.

  8. Modeling and simulation of grid connected permanent magnet generator based small wind energy conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    Arifujjaman, Md.

    2011-07-01

    In order to recover the maximum energy from small scale wind turbine systems many parameters have to be controlled. The aim of this paper is to propose a control strategy for the grid connected PMG-based small wind turbine systems. A mathematical model of small wind turbine systems was developed and the system simulated. Results show demonstrated that the control strategy is highly efficient. Sure enough it reduces the dependence on system variables, diminishes the system complexity, its furling and maximum power point controllers are efficient and it provides a stable operation for multiple wind speeds. This study developed a modeling and control strategy which was proved to be feasible by simulation results.

  9. Mathematics Connection

    African Journals Online (AJOL)

    MATHEMATICS CONNECTION aims at providing a forum topromote the development of Mathematics Education in Ghana. Articles that seekto enhance the teaching and/or learning of mathematics at all levels of theeducational system are welcome.

  10. STABILITY OF LINEAR MULTIAGENT SCALAR SYSTEMS AND ITS DEPENDENCE ON CONNECTIVITY GRAPH

    Directory of Open Access Journals (Sweden)

    S. I. Tomashevich

    2014-03-01

    Full Text Available Multiagent systems are now finding increasingly wide applications in various engineering fields such as energy, transportation, robotics, aviation and others. There are two main aspects to be focused on when organizing multiagent systems: the dynamics of the agents themselves and the ways of their interaction. This interaction is determined by the structure of information connections between agents. Thus, there are several key points of multiagent systems study: the dynamics of individual agents and shape of the information graph. Formation dynamics, in general, is determined by a set of properties of agents and connectivity graph. The paper deals with the relationship between dynamics of agents and Laplace matrix, which is used to set the graph connections. The present research is based on the results given in the known paper by A. Fax and R. Murray (IEEE Trans. AC, 2004. An illustrative example is given, and the application problem of studying the formation dynamics consisting of the group of quadrocopters is presented. Information exchange between agents is determined in the paper by means of the conventional set of graphs. The paper presents an interpretation of the stability conditions and the method of system performance improvement based on these conditions. Motion of quadrocopters group along the flight height is used as an example for methodology application. The simulation results demonstrate the basic dependencies between the information graph shape (and, consequently, the eigenvalues of the Laplacian, which describes this graph and formation stability. Simulation and consideration of Nyquist diagram connection with the key points give an indication of the system stability and take steps to change the control laws. Necessary conditions for the formation stability are obtained on the basis of this research method. Research result makes it possible to create local control laws for agents to ensure the stability of motion in the selected

  11. Grid Connected Solar PV System with SEPIC Converter Compared with Parallel Boost Converter Based MPPT

    Directory of Open Access Journals (Sweden)

    T. Ajith Bosco Raj

    2014-01-01

    Full Text Available The main objective of this work is to study the behaviour of the solar PV systems and model the efficient Grid-connected solar power system. The DC-DC MPPT circuit using chaotic pulse width modulation has been designed to track maximum power from solar PV module. The conversion efficiency of the proposed MPPT system is increased when CPWM is used as a control scheme. This paper also proposes a simplified multilevel (seven level inverter for a grid-connected photovoltaic system. The primary goal of these systems is to increase the energy injected to the grid by keeping track of the maximum power point of the panel, by reducing the switching frequency, and by providing high reliability. The maximum power has been tracked experimentally. It is compared with parallel boost converter. Also this model is based on mathematical equations and is described through an equivalent circuit including a PV source with MPPT, a diode, a series resistor, a shunt resistor, and dual boost converter with active snubber circuit. This model can extract PV power and boost by using dual boost converter with active snubber. By using this method the overall system efficiency is improved thereby reducing the switching losses and cost.

  12. Probability of islanding in utility networks due to grid connected photovoltaic power systems

    Energy Technology Data Exchange (ETDEWEB)

    Verhoeven, B.

    2002-09-15

    This report for the International Energy Agency (IEA) made by Task 5 of the Photovoltaic Power Systems (PVPS) programme takes a look at the probability of islanding in utility networks due to grid-connected photovoltaic power systems. The mission of the Photovoltaic Power Systems Programme is to enhance the international collaboration efforts which accelerate the development and deployment of photovoltaic solar energy. Task 5 deals with issues concerning grid-interconnection and distributed PV power systems. This report summarises the results on a study on the probability of islanding in power networks with a high penetration level of grid connected PV-systems. The results are based on measurements performed during one year in a Dutch utility network. The measurements of active and reactive power were taken every second for two years and stored in a computer for off-line analysis. The area examined and its characteristics are described, as are the test set-up and the equipment used. The ratios between load and PV-power are discussed. The general conclusion is that the probability of islanding is virtually zero for low, medium and high penetration levels of PV-systems.

  13. Detecting resting-state functional connectivity in the language system using functional near-infrared spectroscopy

    Science.gov (United States)

    Zhang, Yu-Jin; Lu, Chun-Ming; Biswal, Bharat B.; Zang, Yu-Feng; Peng, Dan-Lin; Zhu, Chao-Zhe

    2010-07-01

    Functional connectivity has become one of the important approaches to understanding the functional organization of the human brain. Recently, functional near-infrared spectroscopy (fNIRS) was demonstrated as a feasible method to study resting-state functional connectivity (RSFC) in the sensory and motor systems. However, whether such fNIRS-based RSFC can be revealed in high-level and complex functional systems remains unknown. In the present study, the feasibility of such an approach is tested on the language system, of which the neural substrates have been well documented in the literature. After determination of a seed channel by a language localizer task, the correlation strength between the low frequency fluctuations of the fNIRS signal at the seed channel and those at all other channels is used to evaluate the language system RSFC. Our results show a significant RSFC between the left inferior frontal cortex and superior temporal cortex, components both associated with dominant language regions. Moreover, the RSFC map demonstrates left lateralization of the language system. In conclusion, the present study successfully utilized fNIRS-based RSFC to study a complex and high-level neural system, and provides further evidence for the validity of the fNIRS-based RSFC approach.

  14. Vibrations of beams with a variable cross-section fixed on rotational rigid disks

    Directory of Open Access Journals (Sweden)

    Slawomir Zolkiewski

    Full Text Available The work is focused on the problem of vibrating beams with a variable cross-section fixed on a rotational rigid disk. The beam is loaded by a transversal time varying force orthogonal to an axis of the beam and simultaneously parallel to the disk's plane. There are many ways of usage of the technical moveable systems composed of elements with the variable cross-sections. The main applications are used in numerous types of turbines and pumps. The paper is a kind of introduction to the dynamic analysis of above mentioned beam systems. The equations of motion of rotational beams fixed on the rigid disks were derived. After introducing the Coriolis forces and the centrifugal forces, the transportation effect in the mathematical model was considered. This particular project is the first stage research, where there were proposed certain solutions of problems connected with the linear variable cross-sections systems. The further investigation considering the nonlinear systems has been proceeding. The results, analysis and comparison will be presented in the future works.

  15. Research of vibration resistance of non-rigid shafts turning with various technological set-ups

    Directory of Open Access Journals (Sweden)

    Vasilevykh Sergey L.

    2017-01-01

    Full Text Available The article considers the definition of the stability range of a dynamic system for turning non-rigid shafts with different technological set-ups: standard and developed ones; they are improved as a result of this research. The topicality of the study is due to the fact that processing such parts is associated with significant difficulties caused by deformation of the workpiece under the cutting force as well as occurrence of vibration of the part during processing, they are so intense and in practice they force to significantly reduce the cutting regime, recur to multiple-pass operation, lead to premature deterioration of the cutter, as a result, reduce the productivity of machining shafts on metal-cutting machines. In this connection, the purpose of the present research is to determine the boundaries of the stability regions with intensive turning of non-rigid shafts. In the article the basic theoretical principles of construction of a mathematical system focused on the process of non-free cutting of a dynamic machine are justified. By means of the developed mathematical model interrelations are established and legitimacies of influence of various technological set-ups on stability of the dynamic system of the machine-tool-device-tool-blank are revealed. The conducted researches allow to more objectively represent difficult processes that occur in a closed dynamic system of a machine.

  16. Optimal sizing of a hybrid grid-connected photovoltaic and wind power system

    International Nuclear Information System (INIS)

    González, Arnau; Riba, Jordi-Roger; Rius, Antoni; Puig, Rita

    2015-01-01

    Highlights: • Hybrid renewable energy systems are efficient mechanisms to generate electrical power. • This work optimally sizes hybrid grid-connected photovoltaic–wind power systems. • It deals with hourly wind, solar irradiation and electricity demand data. • The system cost is minimized while matching the electricity supply with the demand. • A sensitivity analysis to detect the most critical design variables has been done. - Abstract: Hybrid renewable energy systems (HRES) have been widely identified as an efficient mechanism to generate electrical power based on renewable energy sources (RES). This kind of energy generation systems are based on the combination of one or more RES allowing to complement the weaknesses of one with strengths of another and, therefore, reducing installation costs with an optimized installation. To do so, optimization methodologies are a trendy mechanism because they allow attaining optimal solutions given a certain set of input parameters and variables. This work is focused on the optimal sizing of hybrid grid-connected photovoltaic–wind power systems from real hourly wind and solar irradiation data and electricity demand from a certain location. The proposed methodology is capable of finding the sizing that leads to a minimum life cycle cost of the system while matching the electricity supply with the local demand. In the present article, the methodology is tested by means of a case study in which the actual hourly electricity retail and market prices have been implemented to obtain realistic estimations of life cycle costs and benefits. A sensitivity analysis that allows detecting to which variables the system is more sensitive has also been performed. Results presented show that the model responds well to changes in the input parameters and variables while providing trustworthy sizing solutions. According to these results, a grid-connected HRES consisting of photovoltaic (PV) and wind power technologies would be

  17. Systemic klotho is associated with KLOTHO variation and predicts intrinsic cortical connectivity in healthy human aging.

    Science.gov (United States)

    Yokoyama, Jennifer S; Marx, Gabe; Brown, Jesse A; Bonham, Luke W; Wang, Dan; Coppola, Giovanni; Seeley, William W; Rosen, Howard J; Miller, Bruce L; Kramer, Joel H; Dubal, Dena B

    2017-04-01

    Cognitive decline is a major biomedical challenge as the global population ages. Elevated levels of the longevity factor klotho suppress aging, enhance cognition, and promote synaptic plasticity and neural resilience against aging and Alzheimer's disease (AD)-related pathogenic proteins. Here, we examined the relationship between human genetic variants of KLOTHO and systemic klotho levels - and assessed neuroanatomic correlates of serum klotho in a cohort of healthy older adults. Serum klotho levels were increased with KL-VS heterozygosity, as anticipated. We report, for the first time, that serum klotho levels were paradoxically decreased with KL-VS homozygosity. Further, we found that higher serum klotho levels were associated with measures of greater intrinsic connectivity in key functional networks of the brain vulnerable to aging and AD such as the fronto-parietal and default mode networks. Our findings suggest that elevated klotho promotes a resilient brain, possibly through increased network connectivity of critical brain regions.

  18. Mathematical model validation of a thermal architecture system connecting east/west radiators by flight data

    International Nuclear Information System (INIS)

    Torres, Alejandro; Mishkinis, Donatas; Kaya, Tarik

    2014-01-01

    A novel satellite thermal architecture connecting the east and west radiators of a geostationary telecommunication satellite via loop heat pipes (LHPs) is flight tested on board the satellite Hispasat 1E. The LHP operating temperature is regulated by using pressure regulating valves (PRVs). The flight data demonstrated the successful operation of the proposed concept. A transient numerical model specifically developed for the design of this system satisfactorily simulated the flight data. The validated mathematical model can be used to design and analyze the thermal behavior of more complex architectures. - Highlights: •A novel spacecraft thermal control architecture is presented. •The east–west radiators of a GEO communications satellite are connected using LHPs. •A transient mathematical model is validated with flight data. •The space flight data proved successful in-orbit operation of the novel architecture. •The model can be used to design/analyze LHP based complex thermal architectures

  19. Adaptive Protection Scheme for a Distribution System Considering Grid-Connected and Islanded Modes of Operation

    Directory of Open Access Journals (Sweden)

    Yavuz Ates

    2016-05-01

    Full Text Available The renewable energy-based distributed generation (DG implementation in power systems has been an active research area during the last few decades due to several environmental, economic and political factors. Although the integration of DG offers many advantages, several concerns, including protection schemes in systems with the possibility of bi-directional power flow, are raised. Thus, new protection schemes are strongly required in power systems with a significant presence of DG. In this study, an adaptive protection strategy for a distribution system with DG integration is proposed. The proposed strategy considers both grid-connected and islanded operating modes, while the adaptive operation of the protection is dynamically realized considering the availability of DG power production (related to faults or meteorological conditions in each time step. Besides, the modular structure and fast response of the proposed strategy is validated via simulations conducted on the IEEE 13-node test system.

  20. Zero-voltage ride-through capability of single-phase grid-connected photovoltaic systems

    DEFF Research Database (Denmark)

    Zhang, Zhen; Yang, Yongheng; Ma, Ruiqing

    2017-01-01

    Distributed renewable energy systems play an increasing role in today’s energy paradigm. Thus, intensive research activities have been centered on improving the performance of renewable energy systems, including photovoltaic (PV) systems, which should be of multiple-functionality. That is, the PV...... systems should be more intelligent in the consideration of grid stability, reliability, and fault protection. Therefore, in this paper, the performance of single-phase grid-connected PV systems under an extreme grid fault (i.e., when the grid voltage dips to zero) is explored. It has been revealed...... that combining a fast and accurate synchronization mechanism with appropriate control strategies for the zero-voltage ride-through (ZVRT) operation is mandatory. Accordingly, the representative synchronization techniques (i.e., the phase-locked loop (PLL) methods) in the ZVRT operation are compared in terms...

  1. Support for system connectivity –Learning from evaluating an evaluation

    DEFF Research Database (Denmark)

    Christensen, Jesper Lindgaard

    been sparse on investigat-ing effects of these as well as on the broader criteria to evaluate the innovation networks and functioning of the system. This paper discusses what are such criteria for evaluating innovation policies that rely on enhanc-ing system connectivity and repair system failures......Innovation is said to be dependent upon collaboration and networks. The innovation system thinking empha-sizes networks but also their supporting informal institutions, learning processes, and the relations between actors in the system. Despite the importance of networks, evaluation studies have......? By way of illustration, and as a mean to be specific on these criteria, the paper discusses the possible rationale for governments to support business angel networks (BAN) and what criteria to apply when evaluating such networks. It is found that applying traditional evaluation criteria for assessing...

  2. Rigid external maxillary distraction and rhinoplasty for pyknodysostosis.

    Science.gov (United States)

    Varol, Altan; Sabuncuoglu, Fidan Alakus; Sencimen, Metin; Akcam, Timur; Olmez, Hüseyin; Basa, Selçuk

    2011-05-01

    This article reports the treatment of an 33-year-old female patient with pyknodysostosis by rigid external distraction II midface distraction system. The patient with pyknodysostosis described in this report had severe midfacial hypoplasia. Correction of this by use of routine orthognathic surgery would require osteosynthesis and bone grafting. Risk of infection and/or nonunion after such a surgical procedure was considered too great, and therefore the possibility of treatment by distraction osteogenesis of the maxilla was evaluated. The rigid external distraction II midface distraction system was used to relocate the hypoplastic maxilla at anterior-inferior projection. Distraction osteogenesis should be considered as the primary reconstructive method for maxillofacial deformities in patients with sclerosing bone dysplasias, since this is the second reported case treated successfully with rigid external distraction.

  3. Feasibility Study of Grid Connected PV-Biomass Integrated Energy System in Egypt

    Science.gov (United States)

    Barakat, Shimaa; Samy, M. M.; Eteiba, Magdy B.; Wahba, Wael Ismael

    2016-10-01

    The aim of this paper is to present a feasibility study of a grid connected photovoltaic (PV) and biomass Integrated renewable energy (IRE) system providing electricity to rural areas in the Beni Suef governorate, Egypt. The system load of the village is analyzed through the environmental and economic aspects. The model has been designed to provide an optimal system configuration based on daily data for energy availability and demands. A case study area, Monshaet Taher village (29° 1' 17.0718"N, 30° 52' 17.04"E) is identified for economic feasibility in this paper. HOMER optimization model plan imputed from total daily load demand, 2,340 kWh/day for current energy consuming of 223 households with Annual Average Insolation Incident on a Horizontal Surface of 5.79 (kWh/m2/day) and average biomass supplying 25 tons / day. It is found that a grid connected PV-biomass IRE system is an effective way of emissions reduction and it does not increase the investment of the energy system.

  4. Smoothing of Grid-connected Wind-Diesel Power Output Using Energy Capacitor System

    Directory of Open Access Journals (Sweden)

    Adel A. Elbaset

    2014-06-01

    Full Text Available This paper presents a small hybrid power system consists of two types of power generation; wind turbine and diesel generation, DG connected to power distribution system. The fluctuations like random nature of wind power, turbulent wind, and sudden changes in load demand create imbalances in power distribution that can affect the frequency and the voltage in the power system. So, addition of Energy capacitor System, ECS is useful for compensation of fluctuating power, since it is capable of controlling both active and reactive power simultaneously and can smooth the output power flow. Hence, this paper proposes herein a dynamic model and simulation of a grid connected wind/DG based-ECS with power flow controllers between load and generation. Moreover, the paper presents a study to analyze the leveling of output fluctuation of wind power with the installation of ECS. To control the power exchanged between the ECS system and the AC grid, a load Following Control, LFC based supervisor is proposed with the aim to minimize variations of the power generated by the diesel generator. The interesting performance of the proposed supervisor is shown with the help of simulations. The computer simulation program is confirmed on a realistic circuit model which implemented in the Simulink environment of Matlab and works as if on line.

  5. A report on the performance of a grid connected photovoltaic power generation system

    International Nuclear Information System (INIS)

    Mohd Azhar Abdul Rahman; Mohd Surif Abdul Wahab; Azmi Omar

    2000-01-01

    Malaysia is located almost on the equator and is blessed with an abundance of sunlight almost all year round. So obviously, with the right planning and strategies that are coupled to the right technology and development in the market, the potential for photovoltaic system as an alternative source of power in this country looks promising and is constantly gaining ground and popularity. Sunlight is free and the photovoltaic system is also emission and pollution free which is a guest boost to the current worldwide effort to reduce the global environmental problems. Utility giant Tenaga Nasional Berhad is in line with the Government aspiration to promote the development of solar photovoltaic in the country, who believe in the success and acceptance potential of the photovoltaic system as an alternative source of power generation for long term energy option. In March 1998, a contract was awarded by Tenaga Nasional Berhad to its research subsidiary, Tenaga Nasional Research and Development Sdn. Bhd. to undertake a pilot research project on the development of a grid connected photovoltaic system. This research project is co-funded by the Electric Supply Industry Trust fund. One of the main objective of this research project is to seek the best approach to popularize the Grid Connected Photovoltaic System for domestic as well as suitable commercial premises in this country. This paper will report the initial findings of the project in terms of technical capability and commercial liability. (Author)

  6. Altered resting-state functional connectivity of the frontal-striatal reward system in social anxiety disorder.

    Science.gov (United States)

    Manning, Joshua; Reynolds, Gretchen; Saygin, Zeynep M; Hofmann, Stefan G; Pollack, Mark; Gabrieli, John D E; Whitfield-Gabrieli, Susan

    2015-01-01

    We investigated differences in the intrinsic functional brain organization (functional connectivity) of the human reward system between healthy control participants and patients with social anxiety disorder. Functional connectivity was measured in the resting-state via functional magnetic resonance imaging (fMRI). 53 patients with social anxiety disorder and 33 healthy control participants underwent a 6-minute resting-state fMRI scan. Functional connectivity of the reward system was analyzed by calculating whole-brain temporal correlations with a bilateral nucleus accumbens seed and a ventromedial prefrontal cortex seed. Patients with social anxiety disorder, relative to the control group, had (1) decreased functional connectivity between the nucleus accumbens seed and other regions associated with reward, including ventromedial prefrontal cortex; (2) decreased functional connectivity between the ventromedial prefrontal cortex seed and lateral prefrontal regions, including the anterior and dorsolateral prefrontal cortices; and (3) increased functional connectivity between both the nucleus accumbens seed and the ventromedial prefrontal cortex seed with more posterior brain regions, including anterior cingulate cortex. Social anxiety disorder appears to be associated with widespread differences in the functional connectivity of the reward system, including markedly decreased functional connectivity between reward regions and between reward regions and lateral prefrontal cortices, and markedly increased functional connectivity between reward regions and posterior brain regions.

  7. Determining on-fault magnitude distributions for a connected, multi-fault system

    Science.gov (United States)

    Geist, E. L.; Parsons, T.

    2017-12-01

    A new method is developed to determine on-fault magnitude distributions within a complex and connected multi-fault system. A binary integer programming (BIP) method is used to distribute earthquakes from a 10 kyr synthetic regional catalog, with a minimum magnitude threshold of 6.0 and Gutenberg-Richter (G-R) parameters (a- and b-values) estimated from historical data. Each earthquake in the synthetic catalog can occur on any fault and at any location. In the multi-fault system, earthquake ruptures are allowed to branch or jump from one fault to another. The objective is to minimize the slip-rate misfit relative to target slip rates for each of the faults in the system. Maximum and minimum slip-rate estimates around the target slip rate are used as explicit constraints. An implicit constraint is that an earthquake can only be located on a fault (or series of connected faults) if it is long enough to contain that earthquake. The method is demonstrated in the San Francisco Bay area, using UCERF3 faults and slip-rates. We also invoke the same assumptions regarding background seismicity, coupling, and fault connectivity as in UCERF3. Using the preferred regional G-R a-value, which may be suppressed by the 1906 earthquake, the BIP problem is deemed infeasible when faults are not connected. Using connected faults, however, a solution is found in which there is a surprising diversity of magnitude distributions among faults. In particular, the optimal magnitude distribution for earthquakes that participate along the Peninsula section of the San Andreas fault indicates a deficit of magnitudes in the M6.0- 7.0 range. For the Rodgers Creek-Hayward fault combination, there is a deficit in the M6.0- 6.6 range. Rather than solving this as an optimization problem, we can set the objective function to zero and solve this as a constraint problem. Among the solutions to the constraint problem is one that admits many more earthquakes in the deficit magnitude ranges for both faults

  8. The Economics of Connecting of Small Buildings to Geothermal District Heating Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rafferty, Kevin

    2003-03-01

    Many of the communities co-located with geothermal resources are very small and as a result the buildings they contain tend to be small as well. Generally, small buildings (10,000 ft2) use heating systems which are not hot water based. Since geothermal district heating systems deliver hot water, the costs associated with the conversion of small building heating systems to use hot water for heating is an issue of great influence in terms of the potential development of such systems. This paper examines the typical retrofit costs associated with conversion of small buildings and the level of savings necessary to attract the interest of owners. In general, the prospects for connection of such buildings based only on energy savings is not positive.

  9. The economics of connecting of small buildings to geothermal district heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Rafferty, Kevin

    2001-01-01

    Many of the communities co-located with geothermal resources are very small and as a result the buildings they contain tend to be small as well. Generally, small buildings (10,000 ft2) use heating systems which are not hot water based. Since geothermal district heating systems deliver hot water, the costs associated with the conversion of small building heating systems to use hot water for heating is an issue of great influence in terms of the potential development of such systems. This paper examines the typical retrofit costs associated with conversion of small buildings and the level of savings necessary to attract the interest of owners. In general, the prospects for connection of such buildings based only on energy savings is not positive.

  10. Dynamic analysis of Boushehr Nuclear Power Plant in connected to grid system

    International Nuclear Information System (INIS)

    Karimi Fard, A.

    1999-01-01

    Models of generating with the pressurized water reactor (PWR) have been developed for simulating. the plant dynamics under system disturbances. These models include power plant, energy sources, turbine, transmission system and control system such as Avr and govern and other local control devices. Simulink toolbox of Matlab software is used for simulations. The study is mainly based on the Bushehr Nuclear Power Plants (BNPP) parameters. Assuming that BNPP is connected to infinite bus with double tie line. Four cases are studied to examine the internal dynamic behavior of BNPP. First and second cases are used to load following studies in nuclear power plant. Another cases are used to study the dynamic behavior after short circuit fault and line outages in transmission systems. The results discussed in the thesis

  11. Analysis and Modeling of Interharmonics from Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Sera, Dezso

    2018-01-01

    The industry of solar Photovoltaic (PV) energy and its exploitation are still booming to enhance the sustainability of the society. When PV systems are connected to the grid, challenging issues should be addressed. One of the challenges is related to interharmonics in PV systems, especially...... with a largescale adoption of PV systems. However, the origins of interharmonics remain unclear, although the impact of interhamonics has been reported in literature. Thus, this paper explores the generation mechanisms of interharmonics in PV systems and its characteristics. The exploration reveals...... that the perturbation from the Maximum Power Point Tracking (MPPT) algorithm is one of the origins of interharmonics appearing in the grid current. Accordingly, the MPPT controller parameters such as the perturbation step-size and the sampling rate have an inevitable impact on the interharmonic characteristics...

  12. Chemokines and Heart Disease: A Network Connecting Cardiovascular Biology to Immune and Autonomic Nervous Systems

    Science.gov (United States)

    Dusi, Veronica; Ghidoni, Alice; Ravera, Alice; De Ferrari, Gaetano M.; Calvillo, Laura

    2016-01-01

    Among the chemokines discovered to date, nineteen are presently considered to be relevant in heart disease and are involved in all stages of cardiovascular response to injury. Chemokines are interesting as biomarkers to predict risk of cardiovascular events in apparently healthy people and as possible therapeutic targets. Moreover, they could have a role as mediators of crosstalk between immune and cardiovascular system, since they seem to act as a “working-network” in deep linkage with the autonomic nervous system. In this paper we will describe the single chemokines more involved in heart diseases; then we will present a comprehensive perspective of them as a complex network connecting the cardiovascular system to both the immune and the autonomic nervous systems. Finally, some recent evidences indicating chemokines as a possible new tool to predict cardiovascular risk will be described. PMID:27242392

  13. Research to connect the ozone monitor into irradiation system at Hanoi Irradiation Centre

    International Nuclear Information System (INIS)

    Le Van Huy; Pham Duy Duong; Nguyen Dinh Hung; Vu Quoc Dat

    2013-01-01

    Since 2006, in order to develop radiation technology, Vietnam Atomic Energy Institute has supported Hanoi Irradiation Centre a Project titled: Upgrading the irradiation facility. According to the Project, equipment have been replaced by a new one so that the facility could be suitable for treatment of products. The facility was designed and produced by the former Russia experts. Under normal operating conditions, we are protected by shielding, detection systems, and safety procedures. A system of interlocks prevents unauthorized entry into the radiation chamber when the source is exposed. However, interlocks system have not been warning and preventing ozone gas that can affect human health. So we are having an upgrade as connecting the ozone monitor into irradiation system at Hanoi Irradiation Centre. (author)

  14. A Novel Series Connected Batteries State of High Voltage Safety Monitor System for Electric Vehicle Application

    Directory of Open Access Journals (Sweden)

    Qiang Jiaxi

    2013-01-01

    Full Text Available Batteries, as the main or assistant power source of EV (Electric Vehicle, are usually connected in series with high voltage to improve the drivability and energy efficiency. Today, more and more batteries are connected in series with high voltage, if there is any fault in high voltage system (HVS, the consequence is serious and dangerous. Therefore, it is necessary to monitor the electric parameters of HVS to ensure the high voltage safety and protect personal safety. In this study, a high voltage safety monitor system is developed to solve this critical issue. Four key electric parameters including precharge, contact resistance, insulation resistance, and remaining capacity are monitored and analyzed based on the equivalent models presented in this study. The high voltage safety controller which integrates the equivalent models and control strategy is developed. By the help of hardware-in-loop system, the equivalent models integrated in the high voltage safety controller are validated, and the online electric parameters monitor strategy is analyzed and discussed. The test results indicate that the high voltage safety monitor system designed in this paper is suitable for EV application.

  15. Modeling of Step-up Grid-Connected Photovoltaic Systems for Control Purposes

    Directory of Open Access Journals (Sweden)

    Daniel Gonzalez

    2012-06-01

    Full Text Available This paper presents modeling approaches for step-up grid-connected photovoltaic systems intended to provide analytical tools for control design. The first approach is based on a voltage source representation of the bulk capacitor interacting with the grid-connected inverter, which is a common model for large DC buses and closed-loop inverters. The second approach considers the inverter of a double-stage PV system as a Norton equivalent, which is widely accepted for open-loop inverters. In addition, the paper considers both ideal and realistic models for the DC/DC converter that interacts with the PV module, providing four mathematical models to cover a wide range of applications. The models are expressed in state space representation to simplify its use in analysis and control design, and also to be easily implemented in simulation software, e.g., Matlab. The PV system was analyzed to demonstrate the non-minimum phase condition for all the models, which is an important aspect to select the control technique. Moreover, the system observability and controllability were studied to define design criteria. Finally, the analytical results are illustrated by means of detailed simulations, and the paper results are validated in an experimental test bench.

  16. A novel series connected batteries state of high voltage safety monitor system for electric vehicle application.

    Science.gov (United States)

    Jiaxi, Qiang; Lin, Yang; Jianhui, He; Qisheng, Zhou

    2013-01-01

    Batteries, as the main or assistant power source of EV (Electric Vehicle), are usually connected in series with high voltage to improve the drivability and energy efficiency. Today, more and more batteries are connected in series with high voltage, if there is any fault in high voltage system (HVS), the consequence is serious and dangerous. Therefore, it is necessary to monitor the electric parameters of HVS to ensure the high voltage safety and protect personal safety. In this study, a high voltage safety monitor system is developed to solve this critical issue. Four key electric parameters including precharge, contact resistance, insulation resistance, and remaining capacity are monitored and analyzed based on the equivalent models presented in this study. The high voltage safety controller which integrates the equivalent models and control strategy is developed. By the help of hardware-in-loop system, the equivalent models integrated in the high voltage safety controller are validated, and the online electric parameters monitor strategy is analyzed and discussed. The test results indicate that the high voltage safety monitor system designed in this paper is suitable for EV application.

  17. Vibrations of a connecting system of curved bars, in-plane

    International Nuclear Information System (INIS)

    Suzuki, Katsuyoshi; Takahashi, Shin; Asakura, Akira.

    1979-01-01

    Piping systems were simulated with the combined bars with many kinds of curved and straight shapes. The system consists of straight bars and a circular arc bar, an elliptic arc bar and a catenary curved bar. The inplane vibration of a complicated bar system of any shape, which is indicated by two-dimensional center line, was analyzed strictly and simply, utilizing Lagrangean equation. The theoretical and analytical equations of vibration were derived, such as Lagrangean equation, Euler's equation, and those for bending moment, shearing force, tangential force, deformation, inclination, amplitude frequency, etc. The calculations were conducted on the U-shaped bars, namely the elliptic arc bar connected to straight bars and the catenary bar connected to straight bars, with the boundary condition of fixed ends. The analytical in-plane vibrating characteristics including natural frequency and vibration mode are shown. In the relating experiment, the frequency was measured with the U-shaped test pieces, changing the parameters of the length ratio of elliptic arc and straight part. Both ends were fixed. The test result showed that the vibration characteristics were consistent with the analytical result comparatively. This method is advantageous especially for complicated piping systems. The material and the cross section of bars were not varied in this analysis as the analytical condition. (Nakai, Y.)

  18. An adaptive state of charge estimation approach for lithium-ion series-connected battery system

    Science.gov (United States)

    Peng, Simin; Zhu, Xuelai; Xing, Yinjiao; Shi, Hongbing; Cai, Xu; Pecht, Michael

    2018-07-01

    Due to the incorrect or unknown noise statistics of a battery system and its cell-to-cell variations, state of charge (SOC) estimation of a lithium-ion series-connected battery system is usually inaccurate or even divergent using model-based methods, such as extended Kalman filter (EKF) and unscented Kalman filter (UKF). To resolve this problem, an adaptive unscented Kalman filter (AUKF) based on a noise statistics estimator and a model parameter regulator is developed to accurately estimate the SOC of a series-connected battery system. An equivalent circuit model is first built based on the model parameter regulator that illustrates the influence of cell-to-cell variation on the battery system. A noise statistics estimator is then used to attain adaptively the estimated noise statistics for the AUKF when its prior noise statistics are not accurate or exactly Gaussian. The accuracy and effectiveness of the SOC estimation method is validated by comparing the developed AUKF and UKF when model and measurement statistics noises are inaccurate, respectively. Compared with the UKF and EKF, the developed method shows the highest SOC estimation accuracy.

  19. Series-Connected High Frequency Converters in a DC Microgrid System for DC Light Rail Transit

    Directory of Open Access Journals (Sweden)

    Bor-Ren Lin

    2018-01-01

    Full Text Available This paper studies and presents a series-connected high frequency DC/DC converter connected to a DC microgrid system to provide auxiliary power for lighting, control and communication in a DC light rail vehicle. Three converters with low voltage and current stresses of power devices are series-connected with single transformers to convert a high voltage input to a low voltage output for a DC light rail vehicle. Thus, Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs with a low voltage rating and a turn-on resistance are adopted in the proposed circuit topology in order to decrease power losses on power switches and copper losses on transformer windings. A duty cycle control with an asymmetric pulse-width modulation is adopted to control the output voltage at the desired voltage level. It is also adopted to reduce switching losses on MOSFETs due to the resonant behavior from a leakage inductor of an isolated transformer and output capacitor of MOSFETs at the turn-on instant. The feasibility and effectiveness of the proposed circuit have been verified by a laboratory prototype with a 760 V input and a 24 V/60 A output.

  20. Tank-connected food waste disposer systems--current status and potential improvements.

    Science.gov (United States)

    Bernstad, A; Davidsson, A; Tsai, J; Persson, E; Bissmont, M; la Cour Jansen, J

    2013-01-01

    An unconventional system for separate collection of food waste was investigated through evaluation of three full-scale systems in the city of Malmö, Sweden. Ground food waste is led to a separate settling tank where food waste sludge is collected regularly with a tank-vehicle. These tank-connected systems can be seen as a promising method for separate collection of food waste from both households and restaurants. Ground food waste collected from these systems is rich in fat and has a high methane potential when compared to food waste collected in conventional bag systems. The content of heavy metals is low. The concentrations of N-tot and P-tot in sludge collected from sedimentation tanks were on average 46.2 and 3.9 g/kg TS, equalling an estimated 0.48 and 0.05 kg N-tot and P-tot respectively per year and household connected to the food waste disposer system. Detergents in low concentrations can result in increased degradation rates and biogas production, while higher concentrations can result in temporary inhibition of methane production. Concentrations of COD and fat in effluent from full-scale tanks reached an average of 1068 mg/l and 149 mg/l respectively over the five month long evaluation period. Hydrolysis of the ground material is initiated between sludge collection occasions (30 days). Older food waste sludge increases the degradation rate and the risks of fugitive emissions of methane from tanks between collection occasions. Increased particle size decreases hydrolysis rate and could thus decrease losses of carbon and nutrients in the sewerage system, but further studies in full-scale systems are needed to confirm this. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Design of a steam reforming system to be connected to the HTTR

    International Nuclear Information System (INIS)

    Hada, K.; Nishihara, T.; Shibata, T.; Shiozawa, S.

    1996-01-01

    Top priority objective for developing the first heat utilization system to be connected to the HTTR is to demonstrate technical feasibility of a nuclear process heat utilization system for production of hydrogen for the first time in the world. Major issues to be resolved for coupling the heat utilization system to the HTTR are 1)to develop safety philosophy for reasonably and reliably ensuring safety of the nuclear reactor, 2)to develop control design concept for the total system of the nuclear reactor and heat utilization system because thermal dynamics of endothermic chemical reactor to be heated by nuclear heat is much different from the nuclear reactor, 3)to develop helium-heated components and 4)to develop enhanced hydrogen production technologies for achieving competitiveness to a fossil-fired plant. A steam reforming hydrogen production system was studied as one of the first priority candidates for an HTTR-heat utilization system due to matured technology in fossil-fired plants and since technical solutions demonstrated by the coupling of the steam reforming system to the HTTR will contribute to all other hydrogen production systems. Basic design philosophy for the HTTR-steam reforming system is that the steam reforming plant downstream of an intermediate secondary helium loop is designed at the same safety level as fossil-fired plants and therefore the secondary helium loop was selected as a safety barrier to the HTTR nuclear reactor. (J.P.N.)

  2. Topology and Control of Transformerless High Voltage Grid-connected PV System Based on Cascade Step-up Structure

    DEFF Research Database (Denmark)

    Yang, Zilong; Wang, Zhe; Zhang, Ying

    2017-01-01

    -up structure, instead of applying line-frequency step-up transformer, is proposed to connect PV directly to the 10 kV medium voltage grid. This series-connected step-up PV system integrates with multiple functions, including separated maximum power point tracking (MPPT), centralized energy storage, power...

  3. Impact Analysis of Peng-Hu Power System Connected with a Photovoltaic System

    DEFF Research Database (Denmark)

    Wang, Li; Nguyen, Ha Thi; Yan, Chih-Hao

    2014-01-01

    With the rapid increase of photovoltaic (PV) systems installed in power systems in the recent years, the negative impacts on power quality of distribution networks due to highpenetration PV systems can be increased. This paper presents the system-impact analyzed results of a 0.6-MW PV system conn...

  4. Modeling and design of a multivariable control system for multi-paralleled grid-connected inverters with LCL filter

    DEFF Research Database (Denmark)

    Akhavan, Ali; Mohammadi, Hamid Reza; Guerrero, Josep M.

    2018-01-01

    The quality of injected current in multi-paralleled grid-connected inverters is a matter of concern. The current controlled grid-connected inverters with LCL filter are widely used in the distributed generation (DG) systems due to their fast dynamic response and better power features. However...... with resonances in the system, damping methods such as passive or active damping is necessary. Secondly and perhaps more importantly, paralleled grid-connected inverters in a microgrid are coupled due to grid impedance. Generally, the coupling effect is not taken into account when designing the control systems...

  5. Flapping foil power generator performance enhanced with a spring-connected tail

    Science.gov (United States)

    Liu, Zhengliang; Tian, Fang-Bao; Young, John; Lai, Joseph C. S.

    2017-12-01

    The flexibility effects on the performance of a flapping foil power generator are numerically studied by using the immersed boundary-lattice Boltzmann method at a Reynolds number of 1100. The flapping foil system consists of a rigid NACA0015 foil undergoing harmonic pitch and plunge motions and a passively actuated flat plate pinned to the trailing edge of the rigid foil. The flexibility is modeled by a torsional spring model at the conjuncture of the rigid foil and the tail. Here, a parametric study on mass density and natural frequency is conducted under the optimum kinematic condition of the rigid system identified from the literature and numerical simulations made for reduced frequency f* = 0.04-0.24 and pitch amplitude θ0 = 40°-90°. Four typical cases are discussed in detail by considering time histories of hydrodynamic loads and tail deformations under the optimal and non-optimal kinematic conditions. Results show that under the rigid-system optimal kinematic condition, a tail with appropriate mass density (μ = 0.60) and resonant frequency ( fr*=1.18 ) can improve the maximum efficiency by 7.24% accompanied by an increase of 6.63% in power compared to those of a rigid foil with a rigid tail. This is because the deflection of the tail reduces the low pressure region on the pressure surface (i.e., the lower surface during the upstroke or the upper surface during the downstroke) caused by the leading edge vortex after the stroke reversal, resulting in a higher efficiency. At high flapping frequencies, a spring-connected tail ( fr*=0.13 ) eliminates the large spike in the moment observed in high stiffness cases, reducing the power required for the pitch motion, resulting in 117% improvement in efficiency over that with a rigid tail at a reduced frequency of 0.24.

  6. Undifferentiated Connective Tissue Disease

    Science.gov (United States)

    ... Home Conditions Undifferentiated Connective Tissue Disease (UCTD) Undifferentiated Connective Tissue Disease (UCTD) Make an Appointment Find a Doctor ... by Barbara Goldstein, MD (February 01, 2016) Undifferentiated connective tissue disease (UCTD) is a systemic autoimmune disease. This ...

  7. A software application for energy flow simulation of a grid connected photovoltaic system

    International Nuclear Information System (INIS)

    Hamad, Ayman A.; Alsaad, Mohammad A.

    2010-01-01

    A computer software application was developed to simulate hourly energy flow of a grid connected photovoltaic system. This software application enables conducting an operational evaluation of a studied photovoltaic system in terms of energy exchange with the electrical grid. The system model consists of a photovoltaic array, a converter and an optional generic energy storage component that supports scheduled charging/discharging. In addition to system design parameters, the software uses hourly solar data and hourly load data to determine the amount of energy exchanged with electrical grid for each hour of the simulated year. The resulting information is useful in assessing the impact of the system on demand for electrical energy of a building that uses it. The software also aggregates these hourly results in daily, monthly and full year sums. The software finds the financial benefit of the system as the difference in grid electrical energy cost between two simultaneously considered cases. One is with load supplied only by the electrical grid, while the other is with the photovoltaic system present and contributing energy. The software supports the energy pricing scheme used in Jordan for domestic consumers, which is based on slices of monthly consumption. By projecting the yearly financial results on the system lifetime, the application weighs the financial benefit resulting from using the system against its cost, thus facilitating an economical evaluation.

  8. Grid-connected integrated community energy system. Volume II. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1977-07-01

    A preliminary feasibility analysis of a grid-connected ICES in the City of Independence, Missouri, is presented. It is found that the ICES concept can be made feasible in Independence by employing a 20-MW coal-fired boiler and turbine and using waste heat to provide the energy for heating and cooling commercial facilities with over 3 million square feet of floor space. When fully loaded thermally, the ICES results in favorable fuel utilization and energy conservation in comparison to conventional energy systems. The City of Independence is experienced with all of the institutional factors that may impact the ICES Demonstration Project.

  9. RMS Current of a Photovoltaic Generator in Grid-Connected PV Systems: Definition and Application

    Directory of Open Access Journals (Sweden)

    P. J. Pérez

    2008-01-01

    Full Text Available This paper includes a definition of a new and original concept in the photovoltaic field, RMS current of a photovoltaic generator for grid-connected systems. The RMS current is very useful for calculating energy losses in cables used in a PV generator. As well, a current factor has been defined in order to simplify RMS current calculation. This factor provides an immediate (quick and easy calculation method for the RMS current that does not depend on the case particular conditions (orientation, location, etc.. RMS current and current factor values have been calculated for different locations and modules.

  10. Study of LCL filter performance for inverter fed grid connected system

    Science.gov (United States)

    Thamizh Thentral, T. M.; Geetha, A.; Subramani, C.

    2018-04-01

    The abandoned use of power electronic converters in the application of grid connected system paves a way for critical injected harmonics. Hence the use of filter becomes a significant play among the present scenario. Higher order passive filter is mostly preferred in this application because of its reduced cost and size. This paper focuses on the design of LCL filter for the reduction of injected harmonics. The reason behind choosing LCL filter is inductor sizing and good ripple component attenuation over the other conventional filters. This work is simulated in MATLAB platform and the results are prominent to the objectives mentioned above. Also, the simulation results are verified with the implemented hardware model.

  11. Islanding detection technique using wavelet energy in grid-connected PV system

    Science.gov (United States)

    Kim, Il Song

    2016-08-01

    This paper proposes a new islanding detection method using wavelet energy in a grid-connected photovoltaic system. The method detects spectral changes in the higher-frequency components of the point of common coupling voltage and obtains wavelet coefficients by multilevel wavelet analysis. The autocorrelation of the wavelet coefficients can clearly identify islanding detection, even in the variations of the grid voltage harmonics during normal operating conditions. The advantage of the proposed method is that it can detect islanding condition the conventional under voltage/over voltage/under frequency/over frequency methods fail to detect. The theoretical method to obtain wavelet energies is evolved and verified by the experimental result.

  12. Fault Ride-Through of a Grid-connected Photovoltaic System with Quasi Z Source Inverter

    DEFF Research Database (Denmark)

    Al-Durra, Ahmed; Fayyad, Yara; Muyeen, S.M.

    2016-01-01

    This article presents fault ride-through schemes for a three-phase quasi Z source single-stage photovoltaic (PV) inverter that is connected to the grid after the distribution network. The quasi Z source inverter employs a unique LC network to couple the inverter main circuit to the input of the PV...... the grid side so that the grid fault ride-through requirements can be fulfilled. Scheme A involves control modification in the system; Schemes B and C involve hardware modification in the circuit topology by adding a chopper circuit across the DC link in Scheme B and across the quasi Z source inverter...

  13. Model Predictive Control of Grid Connected Modular Multilevel Converter for Integration of Photovoltaic Power Systems

    DEFF Research Database (Denmark)

    Hajizadeh, Amin; Shahirinia, Amir

    2017-01-01

    Investigation of an advanced control structure for integration of Photovoltaic Power Systems through Grid Connected-Modular Multilevel Converter (GC-MMC) is proposed in this paper. To achieve this goal, a non-linear model of MMC regarding considering of negative and positive sequence components has...... been presented. Then, due to existence of unbalance voltage faults in distribution grid, non-linarites and uncertainties in model, model predictive controller which is developed for GC-MMC. They are implemented based upon positive and negative components of voltage and current to mitigate the power...

  14. A Combined Two-Method MPPT Control Scheme for Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Dorofte, Christinel; Borup, Uffe; Blaabjerg, Frede

    2005-01-01

    In order to increase the output efficiency of a grid-connected photovoltaic (PV) system it is important to have an efficient Maximum Power Point Tracker (MPPT). In the case of low irradiation, the Perturb and Observe (PO) and Incremental Conductance (IC) methods have a poor efficiency, because...... of the poor resolution in the acquired signals, when a fixed point implementation is done. A cost-effective two-method MPPT control scheme is proposed in this paper to track the maximum power point (MPP) at both low and high irradiation, by combining a Constant Voltage (CV) method and modified PO algorithm...

  15. ANALYSIS OF A RIGID WALL IN AN ELASTIC WEIGHTY HALF-PLANE

    Directory of Open Access Journals (Sweden)

    K. V. Dmitrieva

    2016-01-01

    Full Text Available The analysis of stress-strain state of a rigid wall in an elastic weighty half-plane with a broken outline is carried out. To this end, the auxiliary problem of displacements definition in an elastic weighty quarter-plane was solved. Ritz method derived a formula to determine the displacements of elastic flat wedge boundaries in view of its own weight. On the basis of the received expressions the algorithm of displacements definition of a crack in an elastic weighty half-plane with a broken outline is developed. Analytical calculation of a rigid vertical wall located in an elastic weighty half-plane under the influence of a horizontal load, carried out by two methods: by Zhemochkin's method and finite difference method. In the problem statement an elastic half-plane is considered a model of the soil medium, therefore, only compressive normal stresses can arise on the connection of the wall with the elastic base. This assumption implies occurrence of discontinuities soil medium, and leads for the wall to an emergence of two dividing points of boundary conditions. The determination of the boundaries contact of the wall with the elastic half-plane, are not known in advance, is performed by iteratively way at each step set the position of dividing points of boundary conditions and the system of canonical equations of a corresponding method is written.  If tensile stresses appear in wall-base contact and/or there is overlap of the crack edges occurs, then proceeds to the next iteration. Analysis of the results shows that the bending moment and shear forces in sections of the rigid wall in a broken weighty half-plane differ slightly from the same diagrams constructed for a rigid wall in an elastic weightless half-plane. The verification of the results of analytical calculation with the results received by using the LIRA 9.6 that implements the finite element method is obtained. The calculation results for the rigid wall in an elastic weighty half

  16. Rigid-plastic seismic design of reinforced concrete structures

    DEFF Research Database (Denmark)

    Costa, Joao Domingues; Bento, R.; Levtchitch, V.

    2007-01-01

    structural strength with respect to a pre-defined performance parameter using a rigid-plastic response spectrum, which is characteristic of the ground motion alone. The maximum strength demand at any point is solely dependent on the intensity of the ground motion, which facilitates the task of distributing......In this paper a new seismic design procedure for Reinforced Concrete (R/C) structures is proposed-the Rigid-Plastic Seismic Design (RPSD) method. This is a design procedure based on Non-Linear Time-History Analysis (NLTHA) for systems expected to perform in the non-linear range during a lifetime...... earthquake event. The theoretical background is the Theory of Plasticity (Rigid-Plastic Structures). Firstly, a collapse mechanism is chosen and the corresponding stress field is made safe outside the regions where plastic behaviour takes place. It is shown that this allows the determination of the required...

  17. A concise introduction to mechanics of rigid bodies multidisciplinary engineering

    CERN Document Server

    Huang, L

    2017-01-01

    This updated second edition broadens the explanation of rotational kinematics and dynamics — the most important aspect of rigid body motion in three-dimensional space and a topic of much greater complexity than linear motion. It expands treatment of vector and matrix, and includes quaternion operations to describe and analyze rigid body motion which are found in robot control, trajectory planning, 3D vision system calibration, and hand-eye coordination of robots in assembly work, etc. It features updated treatments of concepts in all chapters and case studies. The textbook retains its comprehensiveness in coverage and compactness in size, which make it easily accessible to the readers from multidisciplinary areas who want to grasp the key concepts of rigid body mechanics which are usually scattered in multiple volumes of traditional textbooks. Theoretical concepts are explained through examples taken from across engineering disciplines and links to applications and more advanced courses (e.g. industrial rob...

  18. Impact of Rural Grid-Connected Photovoltaic Generation Systems on Power Quality

    Directory of Open Access Journals (Sweden)

    Rita Pinto

    2016-09-01

    Full Text Available Photovoltaic (PV generation systems have been increasingly used to generate electricity from renewable sources, attracting a growing interest. Recently, grid connected PV micro-generation facilities in individual homes have increased due to governmental policies as well as greater attention by industry. As low voltage (LV distribution systems were built to make energy flow in one direction, the power feed-in of PV generation in rural low-voltage grids can influence power quality (PQ as well as facility operation and reliability. This paper presents results on PQ analysis of a real PV generation facility connected to a rural low-voltage grid. Voltage fluctuations and voltage harmonic contents were observed. Statistical analysis shows a negative impact on PQ produced by this PV facility and also that only a small fraction of the energy available during a sunny day is converted, provoking losses of revenue and forcing the converter to work in an undesirable operating mode. We discuss the disturbances imposed upon the grid and their outcome regarding technical and economic viability of the PV system, as well as possible solutions. A low-voltage grid strengthening has been suggested and implemented. After that a new PQ analysis shows an improvement in the impact upon PQ, making this facility economically viable.

  19. Evaluation of Harmonic Content from a Tap Transformer Based Grid Connection System for Wind Power

    Directory of Open Access Journals (Sweden)

    S. Apelfröjd

    2013-01-01

    Full Text Available Simulations done in MATLAB/Simulink together with experiments conducted at the Ångströms laboratory are used to evaluate and discuss the total harmonic distortion (THD and total demand distortion (TDD of a tap transformer based grid connection system. The grid connection topology can be used with different turbine and generator topologies and is here applied on a vertical axis wind turbine (VAWT with a permanent magnet synchronous generator (PMSG and its operational scheme. The full variable-speed wind conversion system consists of a diode rectifier, DC link, IGBT inverter, LCL-filter, and tap transformer. The full variable-speed operation is enabled by the use of the different step-up ratios of the tap transformer. In the laboratory study, a full experimental setup of the system was used, a clone of the on-site PMSG driven by a motor was used, and the grid was replaced with a resistive load. With a resistive load, grid harmonics and possible unbalances are removed. The results show a TDD and THD below 5% for the full operating range and harmonic values within the limits set up by IEEE-519. Furthermore, a change in tap, going to a lower step-up ratio, results in a reduction in both THD and TDD for the same output power.

  20. Control and Modulation Techniques for a Centralized PV Generation System Grid Connected via an Interleaved Inverter

    Directory of Open Access Journals (Sweden)

    Gianluca Brando

    2016-09-01

    Full Text Available In the context of grid connected photovoitaic (PV generation systems, there are two paramount aspects regarding the Maximum Power Point Tracking (MPPT of the photovoltaic units and the continuity of the service. The most diffused MPPT algorithms are based on either perturb and observe, or on an incremental conductance approach and need both PV current and voltage measurements. Several topology reconfigurable converters are also associated with the PV plants, guaranteeing fault-tolerant features. The generation continuity can also be assured by interleaved inverters, which keep the system operating at reduced maximum power in case of failure. In this paper, an evolution of a hysteresis based MPPT algorithm is presented, based on the measurement of only one voltage, together with a novel space vector modulation suitable for a two-channel three-phase grid connected interleaved inverter. The proposed MMPT algorithm and modulation technique are tested by means of several numerical analyses on a PV generation system of about 200 kW maximum power. The results testify the validity of the proposed strategies, showing good performance, even during a fault occurrence and in the presence of deep shading conditions.

  1. Grid-connection of offshore wind farms using VSC-HVDC systems

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Xiaofan; Dessaint, Louis A. [Ecole de Technologie Superieure, Montreal, QC (Canada). Dept. of Electrical Engineering; Gagnon, Richard [Hydro-Quebec Research Institute, Montreal, QC (Canada)

    2011-07-01

    In this paper, the structure of variable speed PMSG-based offshore wind farms connected to the grid through VSC-HVDC link is presented. And the system models are developed. Also, the corresponding control strategy for this system is proposed. The control objective of the generator side VSC is to achieve the optimal wind power by adjusting the speed of permanent magnet synchronous generator, while the grid side VSC is to maintain DC voltage constant. Furthermore, a case study of 100MW offshore wind farm consisting of 50 individual 2MW PSMG-based wind turbines is developed in MATLAB/SimPowerSystems. Simulation results show the proposed scheme works well. (orig.)

  2. Performance Ratios of Grid Connected Photovoltaic Systems and Theory of Errors

    Directory of Open Access Journals (Sweden)

    Javier Vilariño-García

    2016-07-01

    Full Text Available A detailed analysis of the different levels of dynamic performance of grid connected photovoltaic systems and its interface based on the development of a block diagram explaining the course of energy transformation from solar radiation incident on the solar modules until it becomes useful energy available in the mains. Indexes defined by the Spanish standard                 UNE-EN 61724: Monitoring photovoltaic systems: Guidelines for measurement, data exchange and analysis, are explained from the basics fundaments of block algebra and the transfer function of linear systems. The accuracy requirements demanded by the aforementioned standard for measuring these parameters are discussed in the theory of errors and the real limits of the results obtained. 

  3. Coordinated system services from offshore wind power plants connected through HVDC networks

    DEFF Research Database (Denmark)

    Zeni, Lorenzo; Glasdam, Jakob; Hesselbæk, Bo

    2014-01-01

    This paper presents an overview of power system services in networks involving multiple onshore power systems, a voltage sourced converter (VSC) based high voltage direct current (HVDC) offshore network and an offshore wind power plant (OWPP). A comprehensive list of services regarding onshore...... as well as offshore network operation – both AC and DC – will be discussed from a state of the art perspective. Among them, the most interesting have been selected and will be treated in more detail and the main contribution of this paper will be to shed light on the most relevant aspects related...... to their implementation. For example, new findings on onshore AC voltage control are reported, that help the characterisation of potential AC voltage control that a VSC-HVDC station may offer to an onshore AC grid. The HVDC system behind the VSC-HVDC station may connect, through other converters, to another AC power...

  4. Immunization Information System and Informatics to Promote Immunizations: Perspective From Minnesota Immunization Information Connection.

    Science.gov (United States)

    Muscoplat, Miriam Halstead; Rajamani, Sripriya

    2017-01-01

    The vision for management of immunization information is availability of real-time consolidated data and services for all ages, to clinical, public health, and other stakeholders. This is being executed through Immunization Information Systems (IISs), which are population-based and confidential computerized systems present in most US states and territories. Immunization Information Systems offer many functionalities, such as immunization assessment reports, client follow-up, reminder/recall feature, vaccine management tools, state-supplied vaccine ordering, comprehensive immunization history, clinical decision support/vaccine forecasting and recommendations, data processing, and data exchange. This perspective article will present various informatics tools in an IIS, in the context of the Minnesota Immunization Information Connection.

  5. Operational Planning of Low-Energy District Heating Systems Connected to Existing Buildings

    DEFF Research Database (Denmark)

    Tol, Hakan; Svendsen, Svend

    2012-01-01

    . The response of the radiator heating systems at different levels of supply temperature was used to form the operational planning of the low-energy DH system, which determined the design parameters of the low-energy DH network in terms of overall mass flow requirement and the return temperature from...... the buildings. Since the existing buildings were considered to be renovated to low-energy class, the operational planning was simultaneously modelled for both present high-demand and future low-demand situations of the same case area.......This article focuses on low-energy District Heating (DH) systems operating in low-temperatures such as 55°C in terms of supply and 25°C in terms of return in connection with existing buildings. Since the heat loss from the network has a significant impact in case of supplying heat to low...

  6. A decision support technique for the analysis of autonomous and grid-connected renewable energy systems

    International Nuclear Information System (INIS)

    Akiki, Hadi Boulos

    1996-07-01

    There is an increasing interest in using novel methods to generate electrical energy using wind and solar energy sources. Unfortunately, such energy sources are intermittent, and, therefore, conventional sources must still be available to meet demand during critical periods. In addition, renewable energy technologies are still expensive in general, although extensive research programs are being conducted to overcome this disadvantage. Hence, reliability, economic assessment and environmental impacts are three objectives to be satisfied simultaneously when designing either an autonomous or a grid-connected hybrid power generation system. The installation of any of these two systems should, undoubtedly, be preceded by an assessment of the available resources at the candidate site. In addition, many other factors are to be studied, including economics of transmission lines, site constraints, distances etc. In this thesis, the subjective judgments of various experts, related to the overall approach, are quantified and prioritized using the Analytic Hierarchy Process. Two systems have been considered, an autonomous wind-solar-diesel-battery system and a grid-connected system composed of wind, solar, battery and a grid option. The trade-off/risk method, which is a multi objective planning technique under uncertainty, is used to optimize the size of the system components, so as to give a robust design. A reasonable compromise among the conflicting design objectives in 3-D is sought, under most foreseeable conditions and uncertainties, but with the cost being the dominating objective. Finally, hedging analysis to reduce risk is conducted to cope with the occurrence of any risky future. (author)

  7. Botulinum toxin in myotonia congenita: it does not help against rigidity and pain.

    Science.gov (United States)

    Dressler, Dirk; Adib Saberi, Fereshte

    2014-05-01

    Botulinum toxin (BT) is a potent local muscle relaxant with analgetic properties. Myotonia congenita (MC) is a genetic disorder producing muscle rigidity and pain. BT injected into the trapezius produced mild paresis, but no effect on rigidity and pain. There were no signs of systemic effects. Lack of BT efficacy on MC rigidity confirms its origin from muscle membrane dysfunction rather than from inappropriate neuromuscular activation. Lack of BT efficacy on pain could be caused by lack of anti-rigidity effect. It could also be due to separate non-muscular pain mechanisms unresponsive to BT.

  8. MONOTONIC AND CYCLIC LOADING SIMULATION OF STRUCTURAL STEELWORK BEAM TO COLUMN BOLTED CONNECTIONS WITH CASTELLATED BEAM

    Directory of Open Access Journals (Sweden)

    SAEID ZAHEDI VAHID

    2013-08-01

    Full Text Available Recently steel extended end plate connections are commonly used in rigid steel frame due to its good ductility and ability for energy dissipation. This connection system is recommended to be widely used in special moment-resisting frame subjected to vertical monotonic and cyclic loads. However improper design of beam to column connection can leads to collapses and fatalities. Therefore extensive study of beam to column connection design must be carried out, particularly when the connection is exposed to cyclic loadings. This paper presents a Finite Element Analysis (FEA approach as an alternative method in studying the behavior of such connections. The performance of castellated beam-column end plate connections up to failure was investigated subjected to monotonic and cyclic loading in vertical and horizontal direction. The study was carried out through a finite element analysis using the multi-purpose software package LUSAS. The effect of arranging the geometry and location of openings were also been investigated.

  9. Economic performance and policies for grid-connected residential solar photovoltaic systems in Brazil

    International Nuclear Information System (INIS)

    Mitscher, Martin; Rüther, Ricardo

    2012-01-01

    We analyze the economic competitiveness of grid-connected, distributed solar photovoltaic generation through small-scale rooftop installations in five Brazilian state-capitals. The locations represent a comprehensive set of the two essential parameters for the economic viability of PV—solar irradiation and local electricity tariffs. Levelized electricity costs (LEC) for PV generation and net present values (NPV) for a specific PV system are presented. The analysis comprises three different interest rate scenarios reflecting different conditions for capital acquisition to finance the generators; subsidized, mature market and country-specific risk-adjusted interest. In the NPV analysis, revenue flow is modeled by the sale of PV electricity at current residential tariffs assuming net metering. Using subsidized interest rates, the analysis shows that solar PV electricity is already competitive in Brazil, while in the country-specific risk-adjusted rate, the declining, but still high capital costs of PV make it economically unfeasible. At a mature market interest rate, PV competitiveness is largely dependent on the residential tariff. Economic competitiveness in this scenario is given for locations with high residential tariffs. We demonstrate the high potential of distributed generation with photovoltaic installations in Brazil, and show that under certain conditions, grid-connected PV can be economically competitive in a developing country. - Highlights: ► Debt financed grid-connected PV on Brazilian rooftops can be economically feasible since 2011. ► The cost of capital in Brazil is the decisive parameter in PV competitiveness with conventional generation sources. ► Low-cost, long-term financing is an essential requirement for PV to become an economically justifiable generation alternative. ► The Brazilian market holds huge potential for distributed, residential rooftop PV systems of small size.

  10. Evolving hydrologic connectivity in discontinuous permafrost lowlands: what it means for lake systems

    Science.gov (United States)

    Walvoord, M. A.; Jepsen, S. M.; Rover, J.; Voss, C. I.; Briggs, M. A.

    2015-12-01

    Permafrost influence on the hydrologic connectivity of surface water bodies in high-latitude lowlands is complicated by subsurface heterogeneity and the propensity of the system to change over time. In general, permafrost limits the subsurface exchange of water, solute, and nutrients between lakes and rivers. It follows that permafrost thaw could enhance subsurface hydrologic connectivity among surface water bodies, but the impact of this process on lake distribution is not well known. Changes in the extent of lakes in interior Alaska have important ecological and societal impacts since lakes provide (1) critical habitat for migratory arctic shorebirds and waterfowl, fish, and wildlife, and (2) provisional, recreational, and cultural resources for local communities. We utilize electromagnetic imaging of the shallow subsurface and remote sensing of lake level dynamics in the Yukon Flats of interior Alaska, USA, together with water balance modeling, to gain insight into the influence of discontinuous permafrost on lowland lake systems. In the study region with relatively low precipitation, observations suggest that lakes that are hydrologically isolated during normal conditions are sustained by periodic river flooding events, including ice-jam floods that occur during river ice break-up. Climatically-influenced alterations in flooding frequency and intensity, as well as depth to permafrost, are quantitatively assessed in the context of lake maintenance. Scenario modeling is used to evaluate lake level evolution under plausible changing conditions. Model results demonstrate how permafrost degradation can reduce the dependence of typical lowland lakes on flooding events. Study results also suggest that river flooding may recharge a more spatially widespread zone of lakes and wetlands under future scenarios of permafrost table deepening and enhanced subsurface hydrologic connectivity.

  11. Viscoelastic materials with anisotropic rigid particles: stress-deformation behavior

    NARCIS (Netherlands)

    Sagis, L.M.C.; Linden, van der E.

    2001-01-01

    In this paper we have derived constitutive equations for the stress tensor of a viscoelastic material with anisotropic rigid particles. We have assumed that the material has fading memory. The expressions are valid for slow and small deformations from equilibrium, and for systems that are nearly

  12. Design of Steel Beam-Column Connections

    Directory of Open Access Journals (Sweden)

    Bogatinoski Z.

    2014-05-01

    Full Text Available In this paper a theoretical and experimental research of the steel beam-column connections is presented. Eight types of specimens were being researched, composed of rigid and semi-rigid connections from which 4 connections are with IPE - profile and 4 connections with tube's section for the beam. From the numerical analysis of the researched models, and especially from the experimental research at the Laboratory for Structures in the Faculty of Mechanical Engineering - Skopje, specific conclusions were received that ought to have theoretical and practical usage for researchers in this area of interest.

  13. Supersymmetric Yang-Mills fields as an integrable system and connections with other non-linear systems

    International Nuclear Information System (INIS)

    Chau, L.L.

    1983-01-01

    Integrable properties, i.e., existence of linear systems, infinite number of conservation laws, Reimann-Hilbert transforms, affine Lie algebra of Kac-Moody, and Bianchi-Baecklund transformation, are discussed for the constraint equations of the supersymmetric Yang-Mills fields. For N greater than or equal to 3 these constraint equations give equations of motion of the fields. These equations of motion reduce to the ordinary Yang-Mills equations as the spinor and scalar fields are eliminated. These understandings provide a possible method to solve the full Yang-Mills equations. Connections with other non-linear systems are also discussed. 53 references

  14. Sharing data between mobile devices, connected vehicles, and infrastructure task 3: system requirements specifications (SyRS) final.

    Science.gov (United States)

    2016-07-14

    This report describes the system requirements specifications (SyRS) for the use of mobile devices in a connected vehicle environment. Specifically, it defines the different types of requirements (functional, interface, performance, security, data, an...

  15. Shaping the midwifery profession in Nepal - Uncovering actors' connections using a Complex Adaptive Systems framework.

    Science.gov (United States)

    Bogren, Malin Upper; Berg, Marie; Edgren, Lars; van Teijlingen, Edwin; Wigert, Helena

    2016-12-01

    To explore how actors connect in a system aiming at promoting the establishment of a midwifery profession in Nepal. A qualitative explorative study based on the framework of Complex Adaptive Systems. Semi-structured interviews were conducted with 17 key people representing eight different organisations (actors) promoting the development of the midwifery profession. The actors' connections can be described with a complex set of facilitators for and barriers to promoting the establishment of a midwifery profession. The identified facilitators for this establishment in Nepal are (1) a common goal and (2) a desire to collaborate, whilst the barriers are (1) different political interests and priorities, (2) competing interests of the nursing profession and societal views, (3) divergent academic opinions on a midwifery profession, and (4) insufficient communication. The results also showed that Nepalese society cannot distinguish between nursing and midwifery and that the public support for a midwifery profession was hence minimal. The move of midwifery from an occupation to a profession in Nepal is an on-going, challenging process. The study indicates the importance of understanding the motivations of, and barriers perceived by, actors that can promote or obstruct the establishment of the midwifery profession. It also points to the importance of informing the wider public about the role and responsibility of an autonomous midwifery profession. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Long term performance analysis of a grid connected photovoltaic system in Northern Ireland

    International Nuclear Information System (INIS)

    Mondol, Jayanta Deb; Yohanis, Yigzaw; Smyth, Mervyn; Norton, Brian

    2006-01-01

    The performance of a 13 kW p roof mounted, grid connected photovoltaic system in Northern Ireland over a period of three years has been analysed on hourly, daily and monthly bases. The derived parameters included reference yield, array yield, final yield, array capture losses, system losses, PV and inverter efficiencies and performance ratio. The effects of insolation and inverter operation on the system performance were investigated. The monthly average daily PV, system and inverter efficiencies varied from 4.5% to 9.2%, 3.6% to 7.8% and 50% to 87%, respectively. The annual average PV, system and inverter efficiencies were 7.6%, 6.4% and 75%, respectively. The monthly average daily DC and AC performance ratios ranged from 0.35 to 0.74 and 0.29 to 0.66, respectively. The annual average monthly AC performance ratios for the three years were 0.60, 0.61 and 0.62, respectively. The performance of this system is compared with that of other representative systems internationally

  17. Rigidity of invariant complex structures

    International Nuclear Information System (INIS)

    Miatello, I.D.

    1991-03-01

    A Kaehler solvmanifold is a connected Kaehler manifold (M,j, ) which admits a transition solvable group R of automorphisms. The problem considered in this paper is related to the number of isomorphism classes of Kaehler structures (j, ) on M turning it into a Kaehler solvmanifold. 8 refs

  18. Analytical and experimental position stability of the abutment in different dental implant systems with a conical implant?abutment connection

    OpenAIRE

    Semper-Hogg, Wiebke; Kraft, Silvan; Stiller, Sebastian; Mehrhof, Juergen; Nelson, Katja

    2012-01-01

    Objectives Position stability of the abutment should be investigated in four implant systems with a conical implant?abutment connection. Materials and methods Previously developed formulas and an established experimental setup were used to determine the position stability of the abutment in the four implant systems with a conical implant?abutment connection and different positional index designs: The theoretical rotational freedom was calculated by using the dimensions of one randomly selecte...

  19. Feasibility Study of Residential Grid-Connected Solar Photovoltaic Systems in the State of Indiana

    Science.gov (United States)

    Al-Odeh, Mahmoud

    This study aims to measure the financial viability of installing and using a residential grid-connected PV system in the State of Indiana while predicting its performance in eighteen geographical locations within the state over the system's expected lifetime. The null hypothesis of the study is that installing a PV system for a single family residence in the State of Indiana will not pay for itself within 25 years. Using a systematic approach consisting of six steps, data regarding the use of renewable energy in the State of Indiana was collected from the website of the US Department of Energy to perform feasibility analysis of the installation and use of a standard-sized residential PV system. The researcher was not able to reject the null hypothesis that installing a PV system for a single family residence in the State of Indiana will not pay for itself within 25 years. This study found that the standard PV system does not produce a positive project balance and does not pay for itself within 25 years (the life time of the system) assuming the average cost of a system. The government incentive programs are not enough to offset the cost of installing the system against the cost of the electricity that would not be purchased from the utility company. It can be concluded that the cost of solar PV is higher than the market valuation of the power it produces; thus, solar PV did not compete on the cost basis with the traditional competitive energy sources. Reducing the capital cost will make the standard PV system economically viable in Indiana. The study found that the capital cost for the system should be reduced by 15% - 56%.

  20. Purely non-local Hamiltonian formalism, Kohno connections and ∨-systems

    International Nuclear Information System (INIS)

    Arsie, Alessandro; Lorenzoni, Paolo

    2014-01-01

    In this paper, we extend purely non-local Hamiltonian formalism to a class of Riemannian F-manifolds, without assumptions on the semisimplicity of the product ○ or on the flatness of the connection ∇. In the flat case, we show that the recurrence relations for the principal hierarchy can be re-interpreted using a local and purely non-local Hamiltonian operators and in this case they split into two Lenard-Magri chains, one involving the even terms, the other involving the odd terms. Furthermore, we give an elementary proof that the Kohno property and the ∨-system condition are equivalent under suitable assumptions and we show how to associate a purely non-local Hamiltonian structure to any ∨-system, including degenerate ones

  1. Power system integration of VSC-HVDC connected offshore wind power plants

    DEFF Research Database (Denmark)

    Zeni, Lorenzo; Kjær, Philip Carne

    This report presents an overview of challenges and solutions for the integration into the power system of offshore wind power plants (WPPs) connected to onshore grids through a voltage-source converter based high voltage direct current (VSC-HVDC) transmission system. Aspects that are touched upon...... of the network in the vicinity of the HVDC station and (iii) limiting characteristics of WPPs such as inherent control and communication delays, presence of mechanical resonances at the same frequency as POD and active power ramp-rate limitations. Clustering of wind power plants The proof of concept...... introduction to justify the study, describe the state-of-art and formulate the project’s objectives, the report is essentially divided into three parts, as follows. Control principles of offshore AC networks The control of offshore AC networks relies purely on power electronics, especially if Type 4 wind...

  2. Benchmarking of Constant Power Generation Strategies for Single-Phase Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2018-01-01

    strategies based on: 1) a power control method (P-CPG), 2) a current limit method (I-CPG) and 3) the Perturb and Observe algorithm (P&O-CPG). However, the operational mode changes (e.g., from the maximum power point tracking to a CPG operation) will affect the entire system performance. Thus, a benchmarking...... of the presented CPG strategies is also conducted on a 3-kW single-phase grid-connected PV system. Comparisons reveal that either the P-CPG or I-CPG strategies can achieve fast dynamics and satisfactory steady-state performance. In contrast, the P&O-CPG algorithm is the most suitable solution in terms of high...

  3. Online model-based fault detection for grid connected PV systems monitoring

    KAUST Repository

    Harrou, Fouzi

    2017-12-14

    This paper presents an efficient fault detection approach to monitor the direct current (DC) side of photovoltaic (PV) systems. The key contribution of this work is combining both single diode model (SDM) flexibility and the cumulative sum (CUSUM) chart efficiency to detect incipient faults. In fact, unknown electrical parameters of SDM are firstly identified using an efficient heuristic algorithm, named Artificial Bee Colony algorithm. Then, based on the identified parameters, a simulation model is built and validated using a co-simulation between Matlab/Simulink and PSIM. Next, the peak power (Pmpp) residuals of the entire PV array are generated based on both real measured and simulated Pmpp values. Residuals are used as the input for the CUSUM scheme to detect potential faults. We validate the effectiveness of this approach using practical data from an actual 20 MWp grid-connected PV system located in the province of Adrar, Algeria.

  4. Integration of a finite element generator model into a simulated HVDC connected system

    Energy Technology Data Exchange (ETDEWEB)

    Preston, T W; Sturgess, J P [GEC Alsthom Engineering Research Center, Stafford (United Kingdom)

    1994-12-31

    Within most system analysis programs generators and motors are represented by an equivalent circuit model either a 2-axis model for both stators and rotor or a three-phase model of the stator and a two-axis model of the rotor. This may be adequate under certain operating conditions such as steady-state or some symmetrical faults but for inverter-fed motors or generators feeding into a rectified load a more rigorous model of the machine is required. This paper describes the theory and development of such a model, its integration with the power electronics and application to 6-pulse and 12-pulse converters, the latter being appropriate in systems similar to HVDC unit connection. (author) 5 refs., 16 figs.

  5. Online model-based fault detection for grid connected PV systems monitoring

    KAUST Repository

    Harrou, Fouzi; Sun, Ying; Saidi, Ahmed

    2017-01-01

    This paper presents an efficient fault detection approach to monitor the direct current (DC) side of photovoltaic (PV) systems. The key contribution of this work is combining both single diode model (SDM) flexibility and the cumulative sum (CUSUM) chart efficiency to detect incipient faults. In fact, unknown electrical parameters of SDM are firstly identified using an efficient heuristic algorithm, named Artificial Bee Colony algorithm. Then, based on the identified parameters, a simulation model is built and validated using a co-simulation between Matlab/Simulink and PSIM. Next, the peak power (Pmpp) residuals of the entire PV array are generated based on both real measured and simulated Pmpp values. Residuals are used as the input for the CUSUM scheme to detect potential faults. We validate the effectiveness of this approach using practical data from an actual 20 MWp grid-connected PV system located in the province of Adrar, Algeria.

  6. Microbial growth in domestic hot water systems with special emphasis on connections to district heating networks

    Energy Technology Data Exchange (ETDEWEB)

    Frederiksen, S [Lund Institute of Technology, Dept. of Heat and Power Engineering, Lund (SE); Krongaard Kristensen, K [Regional Food and Hygiene Authority, Koebenhavns Amt Vest, Glostrup (DK)

    1991-01-01

    It is by now well-estalished that domestic hot water systems often harbour Legionella bacteria. Measurements into a number of Danish systems have revealed many other bacteria, among them the thermophilic species Thermus, which is predominantly found on heating coils, where local temperatures are higher. This bacterium not only hampers heat transfer due to fouling, but may also be pathogenic, due to release of endotoxins. Its presence may explain a wide spectrum of symptoms experienced by people after hot baths, such as rashes and itching. The paper summarizes these findings, and on this basis engineering and microbiological considerations are presented in an effort to find ways of future control strategies that go beyond Legionella prevention. Special attention is given to district heating connections, in which low supply and return temperatures are generally wanted in the primary circuit. (author) 16 refs.

  7. Numerical continuation of families of heteroclinic connections between periodic orbits in a Hamiltonian system

    Science.gov (United States)

    Barrabés, E.; Mondelo, J. M.; Ollé, M.

    2013-10-01

    This paper is devoted to the numerical computation and continuation of families of heteroclinic connections between hyperbolic periodic orbits (POs) of a Hamiltonian system. We describe a method that requires the numerical continuation of a nonlinear system that involves the initial conditions of the two POs, the linear approximations of the corresponding manifolds and a point in a given Poincaré section where the unstable and stable manifolds match. The method is applied to compute families of heteroclinic orbits between planar Lyapunov POs around the collinear equilibrium points of the restricted three-body problem in different scenarios. In one of them, for the Sun-Jupiter mass parameter, we provide energy ranges for which the transition between different resonances is possible.

  8. Modeling the Energy Use of a Connected and Automated Transportation System (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Gonder, J.; Brown, A.

    2014-07-01

    Early research points to large potential impacts of connected and automated vehicles (CAVs) on transportation energy use - dramatic savings, increased use, or anything in between. Due to a lack of suitable data and integrated modeling tools to explore these complex future systems, analyses to date have relied on simple combinations of isolated effects. This poster proposes a framework for modeling the potential energy implications from increasing penetration of CAV technologies and for assessing technology and policy options to steer them toward favorable energy outcomes. Current CAV modeling challenges include estimating behavior change, understanding potential vehicle-to-vehicle interactions, and assessing traffic flow and vehicle use under different automation scenarios. To bridge these gaps and develop a picture of potential future automated systems, NREL is integrating existing modeling capabilities with additional tools and data inputs to create a more fully integrated CAV assessment toolkit.

  9. Model Tests of Under Frequency Load Shedding (UFLS for Connected Systems of Continental Europe

    Directory of Open Access Journals (Sweden)

    Marek Głaz

    2016-09-01

    Full Text Available The task force set up by working group System Protection and Dynamics within ENTSO-E model tests of Under Frequency Load Shedding (UFLS for connected systems of continental Europe were carried out. Over 360 simulation scenarios were performed including 16 strategies UFLS, 2 variants of load, 6 types of contingency, with and without considering the impact of dispersed generation. On the basis of calculation results conditions for improving the effectiveness of the UFLS were specified,, including recommended changes of UFLS settings, necessary to achieve this aim. The following report contains a summary description of the test method together with the presentation of selected results of summary calculations and conclusions of the study.

  10. Dynamic response and stability of semi-rigid frames

    Science.gov (United States)

    Abu-Yasein, Omar Ali

    This dissertation presents a method to determine the load capacity as well as end member forces and deformations of frames with partial rigid joint connections by using the direct stiffness method. The connections are modeled as rotational springs attached at the ends of framed members. The lumped mass method, which is an approximate method, and the distributed mass method, which is an exact method, are also presented to compute the natural frequency of frames. The effects of the axial forces and the flexibility of joint connections are both included. Furthermore, the time-dependent response of semi-rigid frames subjected to periodic axial forces is formulated. The harmonic function is approximated by dividing the periodic function into n intervals and the periodic axial forces are evaluated at each time interval as constant forces using 'piecewise approximation'. The regions of instability of frames with different joint stiffness were determined using the characteristic equation method. The time-dependent part of the differential equation for free vibration of a framed member subjected to a harmonic force can be written in the form of the Mathieu-Hill equation where all characteristics of the Mathieu-Hill equation solutions can be used to determine the boundaries of instability regions.

  11. Network connectivity paradigm for the large data produced by weather radar systems

    Science.gov (United States)

    Guenzi, Diego; Bechini, Renzo; Boraso, Rodolfo; Cremonini, Roberto; Fratianni, Simona

    2014-05-01

    The traffic over Internet is constantly increasing; this is due in particular to social networks activities but also to the enormous exchange of data caused especially by the so-called "Internet of Things". With this term we refer to every device that has the capability of exchanging information with other devices on the web. In geoscience (and, in particular, in meteorology and climatology) there is a constantly increasing number of sensors that are used to obtain data from different sources (like weather radars, digital rain gauges, etc.). This information-gathering activity, frequently, must be followed by a complex data analysis phase, especially when we have large data sets that can be very difficult to analyze (very long historical series of large data sets, for example), like the so called big data. These activities are particularly intensive in resource consumption and they lead to new computational models (like cloud computing) and new methods for storing data (like object store, linked open data, NOSQL or NewSQL). The weather radar systems can be seen as one of the sensors mentioned above: it transmit a large amount of raw data over the network (up to 40 megabytes every five minutes), with 24h/24h continuity and in any weather condition. Weather radar are often located in peaks and in wild areas where connectivity is poor. For this reason radar measurements are sometimes processed partially on site and reduced in size to adapt them to the limited bandwidth currently available by data transmission systems. With the aim to preserve the maximum flow of information, an innovative network connectivity paradigm for the large data produced by weather radar system is here presented. The study is focused on the Monte Settepani operational weather radar system, located over a wild peak summit in north-western Italy.

  12. Modeling Of Components Of A Photovoltaic System With Voltage Inverter For Connection To The Electrical Grid

    International Nuclear Information System (INIS)

    Ferreira, Andreza C.; Blasques, Luis C. M.; Galhardo, Marcos A. B.; Pinho, João T.

    2017-01-01

    This paper describes the modeling of the electrical equipment and control mechanisms used in the power conditioning system of a grid-connected photovoltaic system (GCPVS), such as the photovoltaic generator, the DC/DC converter, the voltage inverter with PWM control, its output filter, as well as the converter controls and their functionalities, and the interconnection of the system with the distribution grid and load. In addition to the modeling of the grid-tie inverter, the main equipment of the power conditioning system, this paper describes the synchronization form of the photovoltaic (PV) generation with the electricity distribution grid, considering the power injection control method, the maximum power point tracking technique for maximizing the energy supplied by the photovoltaic generator, and the complete topology of the proposed PV system. The main objective is to provide a computational model capable of simulating the behavior of the GCPVS elements, varying the climatic conditions and the power demand on the AC side, presenting consistent results for different operating conditions, such as variations of climatic parameters (solar irradiance, wind speed, and ambient temperature) and load. In these cases, it is possible to evaluate the behavior of the system, sometimes supplying both the active and reactive power of the load, according to the need. (author)

  13. Evaluation small scale, grid connected wind and solar distributed generation systems in Jordan

    International Nuclear Information System (INIS)

    Naji, G. J.; Tahboub, K. K.; Jalham, I. S.

    2011-01-01

    In this paper, the potential of utilizing wind and solar Private Distributed Generation (PDG) for utility interactive systems is investigated for 11 selected stations (sites) in Jordan. Six customer categories are considered: residential, office, commercial mall, school, hospital and hotel. The main goal of this study was to evaluate the potential of utilizing different grid connected PDG under different conditions such as their location, size, served building category, number of people who share and own the equipment and system type whether wind, solar or hybrid based. It was found that solar systems are still not attractive for all location due to their associated high cost, while wind systems would vary widely depending on the customer category, location and the size of the equipment. Based on the Benefit to Cost ratio criterion, the most attractive sites for installing wind PDGS for residential communities are Ras Muneef, Mafraq, Aqaba, Irbid and H5, while it doesn't seem attractive at Amman,Shoubak, Ghor Essafi, Deir Alla, Maan and H4. On the other hand, the wind on-grid PDGS is very attractive at Ras Muneef, mafraq and Aqaba for commercial buildings, less attractive at H5 and irbid, while it's not attractive at the other sites. The attraction for hybrid PDG systems is closer to those of wind systems alone. (authors).

  14. Management of rigid post-traumatic kyphosis.

    Science.gov (United States)

    Wu, S S; Hwa, S Y; Lin, L C; Pai, W M; Chen, P Q; Au, M K

    1996-10-01

    Rigid post-traumatic kyphosis after fracture of the thoracolumbar and lumbar spine represents a failure of initial management of the injury. Kyphosis moves the center of gravity anterior. The kyphosis and instability may result in pain, deformity, and increased neurologic deficits. Management for symptomatic post-traumatic kyphosis always has presented a challenge to orthopedic surgeons. To evaluate the surgical results of one stage posterior correction for rigid symptomatic post-traumatic kyphosis of the thoracolumbar and lumbar spine. The management for post-traumatic kyphosis remains controversial. Anterior, posterior, or combined anterior and posterior procedures have been advocated by different authors and show various degrees of success. One vertebra immediately above and below the level of the deformity was instrumented posteriorly by a transpedicular system (internal fixator AO). Posterior decompression was performed by excision of the spinal process and bilateral laminectomy. With the deformed vertebra through the pedicle, the vertebral body carefully is removed around the pedicle level, approximating a wedge shape. The extent to which the deformed vertebral body should be removed is determined by the attempted correction. Correction of the deformity is achieved by manipulation of the operating table and compression of the adjacent Schanz screws above and below the lesion. Thirteen patients with post-traumatic kyphosis with symptoms of fatigue and pain caused by slow progression of kyphotic deformities received posterior decompression, correction, and stabilization as a definitive treatment. The precorrection kyphosis ranged from 30-60 degrees, with a mean of 40 degrees +/- 10.8 degrees. After correction, kyphosis was reduced to an average of 1.5 degrees +/- 3.8 degrees, with a range from -5 degrees to 5 degrees. The average angle of correction was 38.8 degrees +/- 10.4 degrees, with a range from 25 degrees to 60 degrees. Significant difference was found

  15. Optimal sizing of a lithium battery energy storage system for grid-connected photovoltaic systems

    OpenAIRE

    Dulout , Jérémy; Anvari-Moghaddam , Amjad ,; Luna , Adriana; Jammes , Bruno; Alonso , Corinne; Guerrero , Josep ,

    2017-01-01

    International audience; This paper proposes a system analysis focused on finding the optimal operating conditions (nominal capacity, cycle depth, current rate, state of charge level) of a lithium battery energy storage system. The purpose of this work is to minimize the cost of the storage system in a renewable DC microgrid. Thus, main stress factors influencing both battery lifetime (calendar and cycling) and performances are described and modelled. Power and energy requirements are also dis...

  16. Impact of lateral flow on the transition from connected to disconnected stream-aquifer systems

    Science.gov (United States)

    Xian, Yang; Jin, Menggui; Liu, Yanfeng; Si, Aonan

    2017-05-01

    Understanding the mechanisms by which stream water infiltrates through streambeds to recharge groundwater systems is essential to sustainable management of scarce water resources in arid and semi-arid areas. An inverted water table (IWT) can develop under a stream in response to the desaturation between the stream and underlying aquifer as the system changes from a connected to disconnected status. However, previous studies have suggested that the IWT can only occur at the bottom of a low permeability streambed in which only the vertical flow between the stream and groundwater during disconnection was assumed. In the present study, numerical simulations revealed that the lateral flow induced by capillarity or heterogeneity also plays an essential role on interactions between streams and aquifers. Three pathways were identified for the transition from connection to disconnection in homogenous systems; notably, the lowest point of an IWT can develop not only at the bottom of the streambed but also within the streambed or the aquifer in response to the initial desaturation at, above, or below the interface between the streambed and aquifer (IBSA), respectively. A sensitivity analysis indicated that in wide streams, the lowest point of an IWT only occurs at the bottom of the streambed; however, for a stream half width of 1 m above a 6 m thick sandy loam streambed, the lowest point occurs in the streambed as stream depth is less than 0.5 m. This critical stream depth increases with streambed thickness and decreases with stream width. Thus, in narrow streams the lowest point can also develop in a thick streambed under a shallow stream. In narrow streams, the lowest point also forms in the aquifer if the ratio of the hydraulic conductivity of the streambed to that of the aquifer is greater than the ratio of the streambed thickness to the sum of the stream depth and the streambed thickness; correspondingly, the streambed is thin but relatively permeable and the stream is

  17. Mesenchymal stem cells for the treatment of systemic lupus erythematosus: is the cure for connective tissue diseases within connective tissue?

    Science.gov (United States)

    Carrion, Flavio A; Figueroa, Fernando E

    2011-05-11

    Mesenchymal stem cells (MSCs) are now known to display not only adult stem cell multipotency but also robust anti-inflammatory and regenerative properties. After widespread in vitro and in vivo preclinical testing in several autoimmune disease models, allogenic MSCs have been successfully applied in patients with severe treatment-refractory systemic lupus erythematosus. The impressive results of these uncontrolled phase I and II trials - mostly in patients with non-responding renal disease - point to the need to perform controlled multicentric trials. In addition, they suggest that there is much to be learned from the basic and clinical science of MSCs in order to reap the full potential of these multifaceted progenitor cells in the treatment of autoimmune diseases.

  18. 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.

  19. Grid-connected photovoltaic power systems. Technical and potential problems. A review

    International Nuclear Information System (INIS)

    Eltawil, Mohamed A.; Zhao, Zhengming

    2010-01-01

    Traditional electric power systems are designed in large part to utilize large baseload power plants, with limited ability to rapidly ramp output or reduce output below a certain level. The increase in demand variability created by intermittent sources such as photovoltaic (PV) presents new challenges to increase system flexibility. This paper aims to investigate and emphasize the importance of the grid-connected PV system regarding the intermittent nature of renewable generation, and the characterization of PV generation with regard to grid code compliance. The investigation was conducted to critically review the literature on expected potential problems associated with high penetration levels and islanding prevention methods of grid tied PV. According to the survey, PV grid connection inverters have fairly good performance. They have high conversion efficiency and power factor exceeding 90% for wide operating range, while maintaining current harmonics THD less than 5%. Numerous large-scale projects are currently being commissioned, with more planned for the near future. Prices of both PV and balance of system components (BOS) are decreasing which will lead to further increase in use. The technical requirements from the utility power system side need to be satisfied to ensure the safety of the PV installer and the reliability of the utility grid. Identifying the technical requirements for grid interconnection and solving the interconnect problems such as islanding detection, harmonic distortion requirements and electromagnetic interference are therefore very important issues for widespread application of PV systems. The control circuit also provides sufficient control and protection functions like maximum power tracking, inverter current control and power factor control. Reliability, life span and maintenance needs should be certified through the long-term operation of PV system. Further reduction of cost, size and weight is required for more utilization of PV

  20. Connected Traveler

    Energy Technology Data Exchange (ETDEWEB)

    2016-06-01

    The Connected Traveler framework seeks to boost the energy efficiency of personal travel and the overall transportation system by maximizing the accuracy of predicted traveler behavior in response to real-time feedback and incentives. It is anticipated that this approach will establish a feedback loop that 'learns' traveler preferences and customizes incentives to meet or exceed energy efficiency targets by empowering individual travelers with information needed to make energy-efficient choices and reducing the complexity required to validate transportation system energy savings. This handout provides an overview of NREL's Connected Traveler project, including graphics, milestones, and contact information.

  1. Aile adaptable : Design du systeme d'actionnement de l'aileron rigide, caracterisation des capteurs de pression et instrumentation pour des tests statiques =

    Science.gov (United States)

    Vincent, Jean-Baptiste

    This Master's thesis is part of a multidisciplinary optimisation project initiated by the Consortium for Research and Innovation in Aerospace in Quebec (CRIAQ) ; this project is about designing and manufacturing a morphing wing demonstrator. The morphing design adopted in this project is based on airfoil thickness variation applied to the upper skin. This morphing generates a change in the laminar to turbulent boundary layer transition position on top of the wing. The position of this transition area leads to significant changes in the aerodynamic performance of the wing. The study presented here focuses on the design of the conventional aileron actuation system and on the characterization of the high sensitivity differential pressure sensors installed on the upper skin in order to determine the laminar to turbulent transition position. Furthermore, the study focuses on the data acquisition system for the morphing wing structural test validation. The aileron actuation system is based on a linear actuator actuated by a brushless motor. The component choice is presented as well as the command method. A static validation as well as wind tunnel validation is presented. The pressure sensor characterization is performed by installing three of those high sensitivity differential pressure sensors in a bi-dimensional known airfoil. This study goes through the process of determining the sensor position in order to observe the transition area by using a computational fluid dynamics (CFD) statistic approach. The validation of the laminar to turbulent transition position is carried out with a series of wind tunnel tests. A structural test has been executed in order to validate the wing structure. This Master's thesis shows the data acquisition system for the microstrain measurement installed inside the morphing wing. A hardware and software architecture description is developed and presented as well as the practical results.

  2. Grid-connected photovoltaic systems for Malaysian residential sector: Effects of component costs, feed-in tariffs, and carbon taxes

    International Nuclear Information System (INIS)

    Lau, K.Y.; Muhamad, N.A.; Arief, Y.Z.; Tan, C.W.; Yatim, A.H.M.

    2016-01-01

    Blessed with abundant solar radiation, Malaysia has a huge potential for grid-connected PV (photovoltaic) installations, particularly for its fast-growing residential sector. Nevertheless, Malaysia's PV installation capacity is relatively small compared with the global PV capacity. Significantly, the pricing mechanisms for grid-connected PV projects need to be appropriately assessed to build up the public's confidence to invest in PV projects. In this paper, we analyze the effects of component costs, FiTs (feed-in tariffs), and carbon taxes on grid-connected PV systems in Malaysian residential sector using the HOMER (Hybrid Optimization of Multiple Energy Resources) software. Results demonstrate that the implementation of grid-connected PV systems is highly feasible with PV array costs of $ 1120/kW or lower. For higher PV array costs up to $ 2320/kW, introducing an FiT rate three times higher ($ 0.30/kWh) than the grid tariff for a 100 kW grid sale capacity will, NPC-wise, prioritize grid-connected PV systems over the utility grid. By implementing the FiT ($ 0.50/kWh) and the carbon tax ($ 36/metric ton) schemes simultaneously, grid-connected PV systems will remain as the optimal systems even for costly PV arrays (up to $ 4000/kW). The findings are of paramount importance as far as PV pricing variability is concerned. - Highlights: • Grid-connected PV for Malaysian residential sector has been analyzed using HOMER. • Component costs, feed-in tariffs, and carbon taxes affect optimal system types. • Grid-connected PV projects are feasible for low PV array costs ($ 1120/kW or lower). • For higher PV array and inverter costs, feed-in tariffs should be implemented. • Combining feed-in tariffs with carbon taxes are effective for further lowering NPCs.

  3. CoNNeCT Antenna Positioning System Dynamic Simulator Modal Model Correlation

    Science.gov (United States)

    Jones, Trevor M.; McNelis, Mark E.; Staab, Lucas D.; Akers, James C.; Suarez, Vicente J.

    2012-01-01

    The National Aeronautics and Space Administration (NASA) developed an on-orbit, adaptable, Software Defined Radios (SDR)/Space Telecommunications Radio System (STRS)-based testbed facility to conduct a suite of experiments to advance technologies, reduce risk, and enable future mission capabilities on the International Space Station (ISS). The Communications, Navigation, and Networking reConfigurable Testbed (CoNNeCT) Project will provide NASA, industry, other Government agencies, and academic partners the opportunity to develop and field communications, navigation, and networking technologies in both the laboratory and space environment based on reconfigurable, software-defined radio platforms and the STRS Architecture. The CoNNeCT Payload Operations Nomenclature is SCAN Testbed, and this nomenclature will be used in all ISS integration, safety, verification, and operations documentation. The SCAN Testbed (payload) is a Flight Releasable Attachment Mechanism (FRAM) based payload that will launch aboard the Japanese H-II Transfer Vehicle (HTV) Multipurpose Exposed Pallet (EP-MP) to the International Space Station (ISS), and will be transferred to the Express Logistics Carrier 3 (ELC3) via Extravehicular Robotics (EVR). The SCAN Testbed will operate on-orbit for a minimum of two years.

  4. Connecting Atlantic temperature variability and biological cycling in two earth system models

    Science.gov (United States)

    Gnanadesikan, Anand; Dunne, John P.; Msadek, Rym

    2014-05-01

    Connections between the interdecadal variability in North Atlantic temperatures and biological cycling have been widely hypothesized. However, it is unclear whether such connections are due to small changes in basin-averaged temperatures indicated by the Atlantic Multidecadal Oscillation (AMO) Index, or whether both biological cycling and the AMO index are causally linked to changes in the Atlantic Meridional Overturning Circulation (AMOC). We examine interdecadal variability in the annual and month-by-month diatom biomass in two Earth System Models with the same formulations of atmospheric, land, sea ice and ocean biogeochemical dynamics but different formulations of ocean physics and thus different AMOC structures and variability. In the isopycnal-layered ESM2G, strong interdecadal changes in surface salinity associated with changes in AMOC produce spatially heterogeneous variability in convection, nutrient supply and thus diatom biomass. These changes also produce changes in ice cover, shortwave absorption and temperature and hence the AMO Index. Off West Greenland, these changes are consistent with observed changes in fisheries and support climate as a causal driver. In the level-coordinate ESM2M, nutrient supply is much higher and interdecadal changes in diatom biomass are much smaller in amplitude and not strongly linked to the AMO index.

  5. Lightning Surge Analysis on a Large Scale Grid-Connected Solar Photovoltaic System

    Directory of Open Access Journals (Sweden)

    Nur Hazirah Zaini

    2017-12-01

    Full Text Available Solar photovoltaic (PV farms currently play a vital role in the generation of electrical power in different countries, such as Malaysia, which is moving toward the use of renewable energy. Malaysia is one of the countries with abundant sunlight and thus can use solar PV farms as alternative sources for electricity generation. However, lightning strikes frequently occur in the country. Being installed in open and flat areas, solar PV farms, especially their electronic components, are at great risk of damage caused by lightning. In this paper, the effects of lightning currents with different peak currents and waveshapes on grid-connected solar PV farms were determined to approximate the level of transient effect that can damage solar PV modules, inverters and transformers. Depending on the location of the solar PV farm, engineer can obtain information on the peak current and median current of the site from the lightning location system (LLS and utilise the results obtained in this study to appropriately assign an SPD to protect the solar panel, inverter and the main panel that connected to the grid. Therefore, the simulation results serve as the basis for controlling the effects of lightning strikes on electrical equipment and power grids where it provides proper justification on the ‘where to be installed’ and ‘what is the rating’ of the SPD. This judgment and decision will surely reduce the expensive cost of repair and replacement of electrical equipment damages due to the lightning.

  6. Grid-connected photovoltaic power systems: survey of inverter and related protection equipments

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, T

    2002-12-15

    This report for the International Energy Agency (IEA) made by Task 5 of the Photovoltaic Power Systems (PVPS) programme reports on a survey made on inverter and related protection equipment. The mission of the Photovoltaic Power Systems Programme is to enhance the international collaboration efforts which accelerate the development and deployment of photovoltaic solar energy. Task 5 deals with issues concerning grid-interconnection and distributed PV power systems. This report summarises the data obtained from survey of recent inverter technology and inverter protection equipment for grid interconnected PV systems. The results are based on the surveys using a questionnaire to identify the current status of grid-interconnection inverters. This report is to serve as a reference for those interested in installing grid-connected PV systems, electric utility company personnel, manufacturers and researchers. The results of the survey are presented and discussed. Technical and financial data is reviewed and two appendices provide details on the results obtained and those institutions involved in the survey.

  7. Sliding-Mode Controller for Maximum Power Point Tracking in Grid-Connected Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Paula Andrea Ortiz Valencia

    2015-11-01

    Full Text Available The maximum power point tracking (MPPT of photovoltaic systems must be as fast and accurate as possible to increase the power production, which eventually increases the PV system profitability. This paper proposes and mathematically analyses a sliding-mode controller to provide a fast and accurate maximum power point tracking in grid-connected photovoltaic systems using a single control stage. This approach avoids the circular dependency in the design of classical cascade controllers used to optimize the photovoltaic system operation, and at the same time, it reduces the number of controllers and avoids the use of linearized models to provide global stability in all the operation range. Such a compact solution also reduces the system cost and implementation complexity. To ensure the stability of the proposed solution, detailed mathematical analyses are performed to demonstrate the fulfillment of the transversality, reachability and equivalent control conditions. Finally, the performance of the proposed solution is validated using detailed simulations, executed in the power electronics simulator PSIM, accounting for both environmental and load perturbations.

  8. Modelling and Simulation of Grid Connected SPV System with Active Power Filtering Features

    Science.gov (United States)

    Saroha, Jaipal; Pandove, Gitanjali; Singh, Mukhtiar

    2017-09-01

    In this paper, the detailed simulation studies for a grid connected solar photovoltaic system (SPV) have been presented. The power electronics devices like DC-DC boost converter and grid interfacing inverter are most important components of proposed system. Here, the DC-DC boost converter is controlled to extract maximum power out of SPV under different irradiation levels, while the grid interfacing inverter is utilized to evacuate the active power and feed it into grid at synchronized voltage and frequency. Moreover, the grid interfacing inverter is also controlled to sort out the issues related to power quality by compensating the reactive power and harmonics current component of nearby load at point of common coupling. Besides, detailed modeling of various component utilized in proposed system is also presented. Finally, extensive simulations have been performed under different irradiation levels with various kinds of load to validate the aforementioned claims. The overall system design and simulation have been performed by using Sim Power System toolbox available in the library of MATLAB.

  9. Performance Analysis of a Grid-Connected Upgraded Metallurgical Grade Silicon Photovoltaic System

    Directory of Open Access Journals (Sweden)

    Chao Huang

    2016-05-01

    Full Text Available Because of their low cost, photovoltaic (PV cells made from upgraded metallurgical grade silicon (UMG-Si are a promising alternative to conventional solar grade silicon-based PV cells. This study investigates the outdoor performance of a 1.26 kW grid-connected UMG-Si PV system over five years, reporting the energy yields and performance ratio and estimating the long-term performance degradation rate. To make this investigation more meaningful, the performance of a mono-Si PV system installed at the same place and studied during the same period of time is presented for reference. Furthermore, this study systematizes and rationalizes the necessity of a data selection and filtering process to improve the accuracy of degradation rate estimation. The impact of plane-of-array irradiation threshold for data filtering on performance ratio and degradation rate is also studied. The UMG-Si PV system’s monthly performance ratio after data filtering ranged from 84% to 93% over the observation period. The annual degradation rate was 0.44% derived from time series of monthly performance ratio using the classical decomposition method. A comparison of performance ratio and degradation rate to conventional crystalline silicon-based PV systems suggests that performance of the UMG-Si PV system is comparable to that of conventional systems.

  10. Development of an Advanced Grid-Connected PV-ECS System Considering Solar Energy Estimation

    Science.gov (United States)

    Rahman, Md. Habibur; Yamashiro, Susumu; Nakamura, Koichi

    In this paper, the development and the performance of a viable distributed grid-connected power generation system of Photovoltaic-Energy Capacitor System (PV-ECS) considering solar energy estimation have been described. Instead of conventional battery Electric Double Layer Capacitors (EDLC) are used as storage device and Photovoltaic (PV) panel to generate power from solar energy. The system can generate power by PV, store energy when the demand of load is low and finally supply the stored energy to load during the period of peak demand. To realize the load leveling function properly the system will also buy power from grid line when load demand is high. Since, the power taken from grid line depends on the PV output power, a procedure has been suggested to estimate the PV output power by calculating solar radiation. In order to set the optimum value of the buy power, a simulation program has also been developed. Performance of the system has been studied for different load patterns in different weather conditions by using the estimated PV output power with the help of the simulation program.

  11. Visualization of Operational Performance of Grid-Connected PV Systems in Selected European Countries

    Directory of Open Access Journals (Sweden)

    Bala Bhavya Kausika

    2018-05-01

    Full Text Available This paper presents the results of the analyses of operational performance of small-sized residential PV systems, connected to the grid, in the Netherlands and some other European countries over three consecutive years. Web scraping techniques were employed to collect detailed yield data at high time resolution (5–15 min from a large number (31,844 of systems with 741 MWp of total capacity, delivering data continuously for at least one year. Annual system yield data was compared from small and medium-sized installations. Cartography and spatial analysis techniques in a geographic information system (GIS were used to visualize yield and performance ratio, which greatly facilitates the assessment of performance for geographically scattered systems. Variations in yield and performance ratios over the years were observed with higher values in 2015 due to higher irradiation values. The potential of specific yield and performance maps lies in the updating of monitoring databases, quality control of data, and availability of irradiation data. The automatic generation of performance maps could be a trend in future mapping.

  12. Optimal Sizing of a Lithium Battery Energy Storage System for Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Dulout, Jeremy; Jammes, Bruno; Alonso, Corinne

    2017-01-01

    This paper proposes a system analysis focused on finding the optimal operating conditions (nominal capacity, cycle depth, current rate, state of charge level) of a lithium battery energy storage system. The purpose of this work is to minimize the cost of the storage system in a renewable DC...... microgrid. Thus, main stress factors influencing both battery lifetime (calendar and cycling) and performances are described and modelled. Power and energy requirements are also discussed through a probabilistic analysis on some years of real data from the ADREAM photovoltaic building of the LAAS...

  13. EXPERIMENTAL STUDY AND PERFORMANCE OF SOLAR ENERGY SYSTEM WITH GRID CONNECTED POWER SUPPLY

    OpenAIRE

    Pradeep Bharti; Dr. A.K.Sharma

    2017-01-01

    In this paper , we are analyzed about the solar power with grid connection using of various component such as PV Cells battery inverter, and grid power connection , in this way we are connected the grid power and solar power , after that finally we are analyzed the power quality of output with the help of various devices.

  14. Altered resting-state effective connectivity of fronto-parietal motor control systems on the primary motor network following stroke

    Science.gov (United States)

    Inman, Cory S.; James, G. Andrew; Hamann, Stephan; Rajendra, Justin K.; Pagnoni, Giuseppe; Butler, Andrew J.

    2011-01-01

    Previous brain imaging work suggests that stroke alters the effective connectivity (the influence neural regions exert upon each other) of motor execution networks. The present study examines the intrinsic effective connectivity of top-down motor control in stroke survivors (n=13) relative to healthy participants (n=12). Stroke survivors exhibited significant deficits in motor function, as assessed by the Fugl-Meyer Motor Assessment. We used structural equation modeling (SEM) of resting-state fMRI data to investigate the relationship between motor deficits and the intrinsic effective connectivity between brain regions involved in motor control and motor execution. An exploratory adaptation of SEM determined the optimal model of motor execution effective connectivity in healthy participants, and confirmatory SEM assessed stroke survivors’ fit to that model. We observed alterations in spontaneous resting-state effective connectivity from fronto-parietal guidance systems to the motor network in stroke survivors. More specifically, diminished connectivity was found in connections from the superior parietal cortex to primary motor cortex and supplementary motor cortex. Furthermore, the paths demonstrated large individual variance in stroke survivors but less variance in healthy participants. These findings suggest that characterizing the deficits in resting-state connectivity of top-down processes in stroke survivors may help optimize cognitive and physical rehabilitation therapies by individually targeting specific neural pathway. PMID:21839174

  15. Development of Acacia Glulam Wood Exterior Beam-to-Column Connection with Angles and Steel Rods System

    Directory of Open Access Journals (Sweden)

    Simanta Djoni

    2017-01-01

    Full Text Available In this paper, two models (M9B1 and M9B2 connection types of acacia glulam wood exterior beam-to-column connections with angles and steel rod system have been developed. Both models have been tested experimentally under monotonic static and cyclic loadings. The behaviour of each model under static and cyclic loadings, maximum displacement, maximum moment, equivalent viscous damping ratio, stiffness degradation, rotational stiffness and ductility have been observed. From the test results it can be concluded that the behaviour of the connections were influenced by the number of bearing steel rods at the beam, wood quality, and thickness of the angles. The M9B1 connection type has more flexibility than the M9B2 connection type. Three dimensional finite element analyses considering anisotropic plasticity have been conducted for both models. It can be concluded that in M9B1 connection type, the tensile forces due to the moment are received by the combination of tensile steel rods and bearing force in the steel rod and wood around it. Overall performance of M9B2 connection type is better than that of M9B1 connection type because the former has higher initial stiffness and higher rotational ductility than the later.

  16. Evaluation of the Lateral Performance of Roof Truss-to-Wall Connections in Light-Frame Wood Systems

    Science.gov (United States)

    Andrew DeRenzis; Vladimir Kochkin; Xiping Wang

    2012-01-01

    This testing program was designed to benchmark the performance of traditional roof systems and incrementally improved roof-to-wall systems with the goal of developing connection solutions that are optimized for performance and constructability. Nine full-size roof systems were constructed and tested with various levels and types of heel detailing to measure the lateral...

  17. The effect of FRT behavior of VSC-HVDC-connected offshore wind power plants on AC/DC system dynamics

    NARCIS (Netherlands)

    van der Meer, A.A.; Ndreko, M.; Gibescu, M.; van der Meijden, M.A.M.M.

    2016-01-01

    Future power systems will contain more converter-based generation, among which are the voltage-source converter-high-voltage direct-current (VSC-HVDC)-connected offshore wind power plants (WPP). Their interaction with the onshore system influences power system dynamics in the transient stability

  18. DISTRIBUTED GRID-CONNECTED PHOTOVOLTAIC POWER SYSTEM EMISSION OFFSET ASSESSMENT: STATISTICAL TEST OF SIMULATED- AND MEASURED-BASED DATA

    Science.gov (United States)

    This study assessed the pollutant emission offset potential of distributed grid-connected photovoltaic (PV) power systems. Computer-simulated performance results were utilized for 211 PV systems located across the U.S. The PV systems' monthly electrical energy outputs were based ...

  19. Anchorage failure of young trees in sandy soils is prevented by a rigid central part of the root system with various designs

    Science.gov (United States)

    Danquechin Dorval, Antoine; Meredieu, Céline; Danjon, Frédéric

    2016-01-01

    Background and Aims Storms can cause huge damage to European forests. Even pole-stage trees with 80-cm rooting depth can topple. Therefore, good anchorage is needed for trees to survive and grow up from an early age. We hypothesized that root architecture is a predominant factor determining anchorage failure caused by strong winds. Methods We sampled 48 seeded or planted Pinus pinaster trees of similar aerial size from four stands damaged by a major storm 3 years before. The trees were gathered into three classes: undamaged, leaning and heavily toppled. After uprooting and 3D digitizing of their full root architectures, we computed the mechanical characteristics of the main components of the root system from our morphological measurements. Key Results Variability in root architecture was quite large. A large main taproot, either short and thick or long and thin, and guyed by a large volume of deep roots, was the major component that prevented stem leaning. Greater shallow root flexural stiffness mainly at the end of the zone of rapid taper on the windward side also prevented leaning. Toppling in less than 90-cm-deep soil was avoided in trees with a stocky taproots or with a very big leeward shallow root. Toppled trees also had a lower relative root biomass – stump excluded – than straight trees. Conclusions It was mainly the flexural stiffness of the central part of the root system that secured anchorage, preventing a weak displacement of the stump. The distal part of the longest taproot and attached deep roots may be the only parts of the root system contributing to anchorage through their maximum tensile load. Several designs provided good anchorage, depending partly on available soil depth. Pole-stage trees are in-between the juvenile phase when they fail by toppling and the mature phase when they fail by uprooting. PMID:27456136

  20. Grid-connected photovoltaic (PV) systems with batteries storage as solution to electrical grid outages in Burkina Faso

    International Nuclear Information System (INIS)

    Abdoulaye, D; Koalaga, Z; Zougmore, F

    2012-01-01

    This paper deals with a key solution for power outages problem experienced by many African countries and this through grid-connected photovoltaic (PV) systems with batteries storage. African grids are characterized by an insufficient power supply and frequent interruptions. Due to this fact, users who especially use classical grid-connected photovoltaic systems are unable to profit from their installation even if there is sun. In this study, we suggest the using of a grid-connected photovoltaic system with batteries storage as a solution to these problems. This photovoltaic system works by injecting the surplus of electricity production into grid and can also deliver electricity as a stand-alone system with all security needed. To achieve our study objectives, firstly we conducted a survey of a real situation of one African electrical grid, the case of Burkina Faso (SONABEL: National Electricity Company of Burkina). Secondly, as study case, we undertake a sizing, a modeling and a simulation of a grid-connected PV system with batteries storage for the LAME laboratory at the University of Ouagadougou. The simulation shows that the proposed grid-connected system allows users to profit from their photovoltaic installation at any time even if the public electrical grid has some failures either during the day or at night.

  1. The formulation of dynamical contact problems with friction in the case of systems of rigid bodies and general discrete mechanical systems—Painlevé and Kane paradoxes revisited

    Science.gov (United States)

    Charles, Alexandre; Ballard, Patrick

    2016-08-01

    The dynamics of mechanical systems with a finite number of degrees of freedom (discrete mechanical systems) is governed by the Lagrange equation which is a second-order differential equation on a Riemannian manifold (the configuration manifold). The handling of perfect (frictionless) unilateral constraints in this framework (that of Lagrange's analytical dynamics) was undertaken by Schatzman and Moreau at the beginning of the 1980s. A mathematically sound and consistent evolution problem was obtained, paving the road for many subsequent theoretical investigations. In this general evolution problem, the only reaction force which is involved is a generalized reaction force, consistently with the virtual power philosophy of Lagrange. Surprisingly, such a general formulation was never derived in the case of frictional unilateral multibody dynamics. Instead, the paradigm of the Coulomb law applying to reaction forces in the real world is generally invoked. So far, this paradigm has only enabled to obtain a consistent evolution problem in only some very few specific examples and to suggest numerical algorithms to produce computational examples (numerical modeling). In particular, it is not clear what is the evolution problem underlying the computational examples. Moreover, some of the few specific cases in which this paradigm enables to write down a precise evolution problem are known to show paradoxes: the Painlevé paradox (indeterminacy) and the Kane paradox (increase in kinetic energy due to friction). In this paper, we follow Lagrange's philosophy and formulate the frictional unilateral multibody dynamics in terms of the generalized reaction force and not in terms of the real-world reaction force. A general evolution problem that governs the dynamics is obtained for the first time. We prove that all the solutions are dissipative; that is, this new formulation is free of Kane paradox. We also prove that some indeterminacy of the Painlevé paradox is fixed in this

  2. Web-based DAQ systems: connecting the user and electronics front-ends

    Science.gov (United States)

    Lenzi, Thomas

    2016-12-01

    Web technologies are quickly evolving and are gaining in computational power and flexibility, allowing for a paradigm shift in the field of Data Acquisition (DAQ) systems design. Modern web browsers offer the possibility to create intricate user interfaces and are able to process and render complex data. Furthermore, new web standards such as WebSockets allow for fast real-time communication between the server and the user with minimal overhead. Those improvements make it possible to move the control and monitoring operations from the back-end servers directly to the user and to the front-end electronics, thus reducing the complexity of the data acquisition chain. Moreover, web-based DAQ systems offer greater flexibility, accessibility, and maintainability on the user side than traditional applications which often lack portability and ease of use. As proof of concept, we implemented a simplified DAQ system on a mid-range Spartan6 Field Programmable Gate Array (FPGA) development board coupled to a digital front-end readout chip. The system is connected to the Internet and can be accessed from any web browser. It is composed of custom code to control the front-end readout and of a dual soft-core Microblaze processor to communicate with the client.

  3. Operational characteristic analysis of PV generation system for grid connection by using a senseless MPPT control

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.-J.; Kim, K.-H.; Park, H.-Y.; Seo, H.-R.; Park, M.; Yu, I.-K. [Changwon National Univ., SarimDong (Korea, Republic of). Dept. of Electrical Engineering

    2007-07-01

    In photovoltaics, the sun's light energy is captured to create electricity. One of the key issues about a photovoltaic (PV) generation system is to keep the output power of photovoltaic cells maximized under any weather conditions. In a conventional maximum power point tracking (MPPT) control method, both voltage and current coming out from PV array require feedback. The system may fail to track the MPP of a PV array when unexpected weather conditions happen. This paper proposed a novel PV output senseless (POS) control method to solve the problem. The proposed POS MPPT control method only had one factor to consider, the load current. To verify this theory, a POS MPPT control was applied to a manufactured PV generation system, and the results of the the simulated and experimental data under real weather conditions were compared and analyzed. Several tables and diagrams were presented, including the circuit diagram of a manufactured PV generation system connected to grid as well as the the specifications of the PV array and PCS used for the experiment. Reasonable results were obtained in this study. In addition, the scheme was found to be very useful in maximizing power from PV array to load with feedback of only the load current. 8 refs., 3 tabs., 15 figs.

  4. A proposed strategy for power optimization of a wind energy conversion system connected to the grid

    International Nuclear Information System (INIS)

    Taraft, S.; Rekioua, D.; Aouzellag, D.; Bacha, S.

    2015-01-01

    Highlights: • Wind energy conversion based doubly fed induction generator controlled by matrix converter. • Operation at both sub and super-synchronous regions is possible with the proposed drive system. • Double the power generated by the DFIG at a twice of speed rated. • Sliding mode control is used to achieve active and reactive power control. - Abstract: Many strategies have been developed in last decade to optimize power extracted from wind energy conversion system where many of them can produce only 30% more than the rated power. With the considered strategy, the generated wind power can reach twice its nominal value using a fast and reliable fully rugged electrical control. Indeed, by employing a suitable control technique where the produced power in super-synchronous mode is derived from both the stator and the rotor. Also, the rotor provided power in this case grows up 100% comparing to stator rated power. However, this solution permits to maintain the wind energy conversion system operation in its stable area. The considered system consists of a double fed induction generator whose stator is connected directly to the grid and its rotor is supplied by matrix converter. In this paper, the sliding mode approach to achieve active and reactive power control is used. This latter is combined with de Perturbation and Observation Maximum Power Point Tracking used in the second operation zone. The obtained simulations results are assessed and carried out using Matlab/Simulink package and show the performance and the effectiveness of the proposed control

  5. Web-based DAQ systems: connecting the user and electronics front-ends

    International Nuclear Information System (INIS)

    Lenzi, Thomas

    2016-01-01

    Web technologies are quickly evolving and are gaining in computational power and flexibility, allowing for a paradigm shift in the field of Data Acquisition (DAQ) systems design. Modern web browsers offer the possibility to create intricate user interfaces and are able to process and render complex data. Furthermore, new web standards such as WebSockets allow for fast real-time communication between the server and the user with minimal overhead. Those improvements make it possible to move the control and monitoring operations from the back-end servers directly to the user and to the front-end electronics, thus reducing the complexity of the data acquisition chain. Moreover, web-based DAQ systems offer greater flexibility, accessibility, and maintainability on the user side than traditional applications which often lack portability and ease of use. As proof of concept, we implemented a simplified DAQ system on a mid-range Spartan6 Field Programmable Gate Array (FPGA) development board coupled to a digital front-end readout chip. The system is connected to the Internet and can be accessed from any web browser. It is composed of custom code to control the front-end readout and of a dual soft-core Microblaze processor to communicate with the client.

  6. Economic and Environmental Study of Wineries Powered by Grid-Connected Photovoltaic Systems in Spain

    Directory of Open Access Journals (Sweden)

    Daniel Gómez-Lorente

    2017-02-01

    Full Text Available This research developed a system that can make factories more independent from the grid. The system enhances efficiency since factory operation is powered by the renewable energy generated during the production process. Winemaking is a key sector that can profit from such a system because wineries can recycle much of the waste from the raw materials employed in wine production. Moreover, the solar energy collected at winemaking facilities can also be used to reduce electricity consumption and thus increase energy efficiency. This study investigated the feasibility of using renewable energy sources, such as solar energy, in wineries in Spain, given the quantity of renewable energy produced in the country. For this purpose, cost-effectiveness, power generation, CO2 emissions and the renewable energy fraction were taken into account. The assumption was that the photovoltaic system was grid-connected. Research results showed a reduction in electrical power costs ranging from 4% to 36%. This reduction was accompanied by an increase in the use of renewable energy of up to 57%. The results obtained are based on self-consumption or net metering policy as well as the production capacity of the winery.

  7. Economical justification in usage of heat pump connected to the turbine cooling system

    International Nuclear Information System (INIS)

    Mijakovski, Vladimir; Josifovski, Vasko

    2008-01-01

    Orangery or greenhouse presents building with micro climate quite different from the external, that is internal temperature is substantially different from the external air temperature. Part of the solar energy is absorbed by plants and ground, part is transformed to heat energy, thus heating internal air. That is the reason, depending on the local climate conditions, heat radiation covers 30 to 60 % of the total heat energy needs for the orangery. Economical justification for the connection of heat pump to the cold end of the turbine in the orangerie's (green-house) heating system is presented in this paper. Rationality from the usage of low-temperature heat energy from the turbine's cold-end comes from techno-economical and ecological aspect. (Author)

  8. Implementation of fuzzy-sliding mode based control of a grid connected photovoltaic system.

    Science.gov (United States)

    Menadi, Abdelkrim; Abdeddaim, Sabrina; Ghamri, Ahmed; Betka, Achour

    2015-09-01

    The present work describes an optimal operation of a small scale photovoltaic system connected to a micro-grid, based on both sliding mode and fuzzy logic control. Real time implementation is done through a dSPACE 1104 single board, controlling a boost chopper on the PV array side and a voltage source inverter (VSI) on the grid side. The sliding mode controller tracks permanently the maximum power of the PV array regardless of atmospheric condition variations, while The fuzzy logic controller (FLC) regulates the DC-link voltage, and ensures via current control of the VSI a quasi-total transit of the extracted PV power to the grid under a unity power factor operation. Simulation results, carried out via Matlab-Simulink package were approved through experiment, showing the effectiveness of the proposed control techniques. Copyright © 2015. Published by Elsevier Ltd.

  9. Implementation of the Lanczos algorithm for the Hubbard model on the Connection Machine system

    International Nuclear Information System (INIS)

    Leung, P.W.; Oppenheimer, P.E.

    1992-01-01

    An implementation of the Lanczos algorithm for the exact diagonalization of the two dimensional Hubbard model on a 4x4 square lattice on the Connection Machine CM-2 system is described. The CM-2 is a massively parallel machine with distributed memory. The program is written in C/PARIS. This implementation minimizes memory usage by generating the matrix elements as needed instead of storing them. The Lanczos vectors are stored across the local memory of the processors. Using translational symmetry only, the dimension of the Hilbert space at half filling is more than 10 million. A speed of about 2.4 min per iteration is achieved on a 64K CM-2. This implementation is scalable. Running it on a bigger machine with more processors speeds up the process. The performance analysis of this implementation is shown and discuss its advantages and disadvantages are discussed

  10. An economic evaluation of photovoltaic grid connected systems (PVGCS) in Flanders for companies: A generic model

    International Nuclear Information System (INIS)

    Audenaert, Amaryllis; De Boeck, Liesje; De Cleyn, Sven; Lizin, Sebastien; Adam, Jean-Francois

    2010-01-01

    In this paper an economic evaluation of photovoltaic grid connected systems (PVGCS) for companies situated in Flanders (Belgium) is conducted by using a generic Excel model. The model is unique in that it includes the dimension of taxation. This inclusion is required, otherwise the fiscal benefit of using solar panels is not accounted for. The model uses the cash flow projection method. This technique allows the calculation of the following classical evaluation criteria: net present value, internal rate of return, payback period, discounted payback period, profitability index, yield unit cost, yield unit revenue and break-even turnkey cost. Their outcome makes it possible to answer the question whether installing a PVGCS in Flanders is a responsible financial investment for companies. Furthermore, the paper estimates whether the corporate environment is ready for a subsidy legislation change. This change has recently been announced and as such it is possible to gauge whether the current market situation is profitable given future legislation. (author)

  11. Data on the configuration design of internet-connected home cooling systems by engineering students.

    Science.gov (United States)

    McComb, Christopher; Cagan, Jonathan; Kotovsky, Kenneth

    2017-10-01

    This experiment was carried out to record the step-by-step actions that humans take in solving a configuration design problem, either in small teams or individually. Specifically, study participants were tasked with configuring an internet-connected system of products to maintain temperature within a home, subject to cost constraints. Every participant was given access to a computer-based design interface that allowed them to construct and assess solutions. The interface was also used to record the data that is presented here. In total, data was collected for 68 participants, and each participant was allowed to perform 50 design actions in solving the configuration design problem. Major results based on the data presented here have been reported separately, including initial behavioral analysis (McComb et al.) [1], [2] and design pattern assessments via Markovian modeling (McComb et al., 2017; McComb et al., 2017) [3], [4].

  12. Modal analysis of a grid-connected direct-drive permanent magnet synchronous generator wind turbine system

    DEFF Research Database (Denmark)

    Tan, Jin; Wang, Xiao Ru; Chen, Zhe

    2013-01-01

    In order to study the stability of a grid-connected direct-drive permanent magnet synchronous generator (PMSG) wind turbine systems, this paper presents the modal analysis of a PMSG wind turbine system. A PMSG model suitable for small signal stability analysis is presented. The modal properties...... of a grid-connected PMSG wind turbine system are studied. Then the comprehensive impacts of the shaft model, shaft parameters, operation points and lengths of the transmission line on the modal characteristic of the system are investigated by the eigenvalue analysis method. Meanwhile, the corresponding...... analysis. It offers a better understanding about the essence of the stability of grid-connected PMSG wind turbine system....

  13. Identification of the Most Effective Point of Connection for Battery Energy Storage Systems Focusing on Power System Frequency Response Improvement

    Directory of Open Access Journals (Sweden)

    Thiago Pieroni

    2018-03-01

    Full Text Available With the massive penetration of intermittent generation (wind and solar, the reduction of Electrical Power Systems’ (EPSs inertial frequency response represents a new challenge. One alternative to deal with this scenario may be the application of a Battery Energy Storage System (BESS. However, the main constraint for the massive deployment of BESSs is the high acquisition cost of these storage systems which in some situations, can preclude their use in transmission systems. The main goal of this paper is to propose a systematic procedure to include BESSs in power system aiming to improve the power system frequency response using full linear models and geometric measures. In this work, a generic battery model is developed in a two-area test system with assumed high wind penetration and full conventional generators models. The full power system is linearized, and the geometric measures of controllability associated with of the frequency regulation mode are estimated. Then, these results are used to identify the most effective point of connection for a BESS aiming at the improvement of the power system frequency response. Nonlinear time-domain simulations are carried out to evaluate and validate the results.

  14. Electro-mechanical connection system for ITER in-vessel magnetic sensors

    Energy Technology Data Exchange (ETDEWEB)

    Rizzolo, Andrea; Brombin, Matteo; Gonzalez, Winder [Consorzio RFX, Corso Stati Uniti, 4, 35127 Padova (Italy); Marconato, Nicolò, E-mail: nicolo.marconato@igi.cnr.it [Consorzio RFX, Corso Stati Uniti, 4, 35127 Padova (Italy); Peruzzo, Simone [Consorzio RFX, Corso Stati Uniti, 4, 35127 Padova (Italy); Arshad, Shakeib [Fusion for Energy, C/Josep Pla, 2, 08019 Barcelona (Spain); Ma, Yunxing; Vayakis, George [ITER Organization, Route de Vinon-sur-Verdon, 13067 St Paul Lez Durance (France); Williams, Adrian [Oxford Technologies Ltd, 7 Nuffield Way, Abingdon, Oxon, OX14 1RL (United Kingdom)

    2016-11-01

    Highlights: • Latest status of the ITER “Generic In-Vessel Magnetic Platform” design activity. • Integration within the ITER In-Vessel configuration model. • Geometry optimization based on thermo-mechanical and magnetic field 3D calculation. • Assessment of the remote handling maintenance compatibility. - Abstract: This paper presents the preliminary design of the “In-Vessel Magnetic platform”, which is a subsystem of the magnetic diagnostics formed by all the components necessary for guaranteeing the thermo-mechanical interface of the actual magnetic sensors with the vacuum vessel (VV), their protection and the electrical connection to the in-vessel wiring for the transmission of the detected signal with a minimum level of noise. The design has been developed in order to comply with different functional requirements: the mechanical attachment to the VV; the electrical connection to the in-vessel wiring; efficient heat transfer to the VV; the compatibility with Remote Handling (RH) system for replacement; the integration of metrology features for post-installation control; the Electro Magnetic Interference (EMI) shielding from Electron Cyclotron Heating (ECH) stray radiation without compromising the sensor pass band (15 kHz). Significant effort has been dedicated to develop the CAD model, integrated within the ITER In-Vessel configuration model, taking care of the geometrical compliance with the Blanket modules (modified in order to accommodate the magnetic sensors in suitable grooves) and the RH compatibility. Thorough thermo-mechanical and electro-magnetic Finite Element Method (FEM) analyses have been performed to assess the reliability of the system in standard and off-normal operating conditions for the low frequency magnetic sensors.

  15. Large scale rooftop photovoltaics grid connected system at Charoenphol-Rama I green building

    Energy Technology Data Exchange (ETDEWEB)

    Ketjoy, N.; Rakwichian, W. [School of Renewable Energy Technology (SERT) (Thailand); Wongchupan, V. [Panya Consultants Co., Ltd (Thailand); Sankarat, T. [Tesco Lotus, Ek-Chai Distribution System Co., Ltd. (Thailand)

    2004-07-01

    This paper presents a technical feasibility study project for the large scale rooftop photovoltaics (PV) grid connected system at Charoenphol-Rama I green building super store of TESCO LOTUS (TL) in Thailand. The objective of this project is (i) to study the technical feasibility of installation 350 kWp PV systems on the top of the roof in this site (ii) and to determine the energy produce from this system. The technical factors are examined using a computerized PVS 2000 simulation and assessment tool. This super store building located in Bangkok, with latitude 14 N, longitude 100 E and the building direction is 16 from North direction. The building roof area is 14,000 m2; with 3 degree face East and 3 degree face West pitch. Average daily solar energy in this area is approximately 5.0 kWh. The study team for this project consists of educational institution as School of Renewable Energy Technology (SERT) and private institution as Panya Consultants (PC). TL is the project owner, PC is responsible for project management, and SERT is a third party and responsible for PV system study, conceptual design and all technical process. In this feasibility studies SERT will identify the most attractive scenarios of photovoltaic cell technology (mono, poly-crystalline or thin film amorphous), system design concepts for owners (TL) and determine possibility of the energy yield of the system from different module orientation and tilt angle. The result of this study is a guide to help TL to make decision to select proper rooftop PV system option for this store with proper technology view. The economic view will not be considered in this study. (orig.)

  16. Systems level analysis of systemic sclerosis shows a network of immune and profibrotic pathways connected with genetic polymorphisms.

    Directory of Open Access Journals (Sweden)

    J Matthew Mahoney

    2015-01-01

    Full Text Available Systemic sclerosis (SSc is a rare systemic autoimmune disease characterized by skin and organ fibrosis. The pathogenesis of SSc and its progression are poorly understood. The SSc intrinsic gene expression subsets (inflammatory, fibroproliferative, normal-like, and limited are observed in multiple clinical cohorts of patients with SSc. Analysis of longitudinal skin biopsies suggests that a patient's subset assignment is stable over 6-12 months. Genetically, SSc is multi-factorial with many genetic risk loci for SSc generally and for specific clinical manifestations. Here we identify the genes consistently associated with the intrinsic subsets across three independent cohorts, show the relationship between these genes using a gene-gene interaction network, and place the genetic risk loci in the context of the intrinsic subsets. To identify gene expression modules common to three independent datasets from three different clinical centers, we developed a consensus clustering procedure based on mutual information of partitions, an information theory concept, and performed a meta-analysis of these genome-wide gene expression datasets. We created a gene-gene interaction network of the conserved molecular features across the intrinsic subsets and analyzed their connections with SSc-associated genetic polymorphisms. The network is composed of distinct, but interconnected, components related to interferon activation, M2 macrophages, adaptive immunity, extracellular matrix remodeling, and cell proliferation. The network shows extensive connections between the inflammatory- and fibroproliferative-specific genes. The network also shows connections between these subset-specific genes and 30 SSc-associated polymorphic genes including STAT4, BLK, IRF7, NOTCH4, PLAUR, CSK, IRAK1, and several human leukocyte antigen (HLA genes. Our analyses suggest that the gene expression changes underlying the SSc subsets may be long-lived, but mechanistically interconnected

  17. Energy efficiency design strategies for buildings with grid-connected photovoltaic systems

    Science.gov (United States)

    Yimprayoon, Chanikarn

    The building sector in the United States represents more than 40% of the nation's energy consumption. Energy efficiency design strategies and renewable energy are keys to reduce building energy demand. Grid-connected photovoltaic (PV) systems installed on buildings have been the fastest growing market in the PV industry. This growth poses challenges for buildings qualified to serve in this market sector. Electricity produced from solar energy is intermittent. Matching building electricity demand with PV output can increase PV system efficiency. Through experimental methods and case studies, computer simulations were used to investigate the priorities of energy efficiency design strategies that decreased electricity demand while producing load profiles matching with unique output profiles from PV. Three building types (residential, commercial, and industrial) of varying sizes and use patterns located in 16 climate zones were modeled according to ASHRAE 90.1 requirements. Buildings were analyzed individually and as a group. Complying with ASHRAE energy standards can reduce annual electricity consumption at least 13%. With energy efficiency design strategies, the reduction could reach up to 65%, making it possible for PV systems to meet reduced demands in residential and industrial buildings. The peak electricity demand reduction could be up to 71% with integration of strategies and PV. Reducing lighting power density was the best single strategy with high overall performances. Combined strategies such as zero energy building are also recommended. Electricity consumption reductions are the sum of the reductions from strategies and PV output. However, peak electricity reductions were less than their sum because they reduced peak at different times. The potential of grid stress reduction is significant. Investment incentives from government and utilities are necessary. The PV system sizes on net metering interconnection should not be limited by legislation existing in

  18. Influence of abutment materials on the implant-abutment joint stability in internal conical connection type implant systems

    OpenAIRE

    Jo, Jae-Young; Yang, Dong-Seok; Huh, Jung-Bo; Heo, Jae-Chan; Yun, Mi-Jung; Jeong, Chang-Mo

    2014-01-01

    PURPOSE This study evaluated the influence of abutment materials on the stability of the implant-abutment joint in internal conical connection type implant systems. MATERIALS AND METHODS Internal conical connection type implants, cement-retained abutments, and tungsten carbide-coated abutment screws were used. The abutments were fabricated with commercially pure grade 3 titanium (group T3), commercially pure grade 4 titanium (group T4), or Ti-6Al-4V (group TA) (n=5, each). In order to assess ...

  19. Removal of suspended solids and turbidity from marble processing wastewaters by electrocoagulation: Comparison of electrode materials and electrode connection systems

    Energy Technology Data Exchange (ETDEWEB)

    Solak, Murat [Duezce University, Kaynasli Vocational School, Environmental Protection and Control Department, 81900 Duezce (Turkey); Kilic, Mehmet, E-mail: kavi@mmf.sdu.edu.tr [Sueleyman Demirel University, Engineering and Architecture Faculty, Environmental Engineering Department, 32260 Isparta (Turkey); Hueseyin, Yazici; Sencan, Aziz [Sueleyman Demirel University, Engineering and Architecture Faculty, Environmental Engineering Department, 32260 Isparta (Turkey)

    2009-12-15

    In this study, removal of suspended solids (SS) and turbidity from marble processing wastewaters by electrocoagulation (EC) process were investigated by using aluminium (Al) and iron (Fe) electrodes which were run in serial and parallel connection systems. To remove these pollutants from the marble processing wastewater, an EC reactor including monopolar electrodes (Al/Fe) in parallel and serial connection system, was utilized. Optimization of differential operation parameters such as pH, current density, and electrolysis time on SS and turbidity removal were determined in this way. EC process with monopolar Al electrodes in parallel and serial connections carried out at the optimum conditions where the pH value was 9, current density was approximately 15 A/m{sup 2}, and electrolysis time was 2 min resulted in 100% SS removal. Removal efficiencies of EC process for SS with monopolar Fe electrodes in parallel and serial connection were found to be 99.86% and 99.94%, respectively. Optimum parameters for monopolar Fe electrodes in both of the connection types were found to be for pH value as 8, for electrolysis time as 2 min. The optimum current density value for Fe electrodes used in serial and parallel connections was also obtained at 10 and 20 A/m{sup 2}, respectively. Based on the results obtained, it was found that EC process running with each type of the electrodes and the connections was highly effective for the removal of SS and turbidity from marble processing wastewaters, and that operating costs with monopolar Al electrodes in parallel connection were the cheapest than that of the serial connection and all the configurations for Fe electrode.

  20. Removal of suspended solids and turbidity from marble processing wastewaters by electrocoagulation: Comparison of electrode materials and electrode connection systems

    International Nuclear Information System (INIS)

    Solak, Murat; Kilic, Mehmet; Hueseyin, Yazici; Sencan, Aziz

    2009-01-01

    In this study, removal of suspended solids (SS) and turbidity from marble processing wastewaters by electrocoagulation (EC) process were investigated by using aluminium (Al) and iron (Fe) electrodes which were run in serial and parallel connection systems. To remove these pollutants from the marble processing wastewater, an EC reactor including monopolar electrodes (Al/Fe) in parallel and serial connection system, was utilized. Optimization of differential operation parameters such as pH, current density, and electrolysis time on SS and turbidity removal were determined in this way. EC process with monopolar Al electrodes in parallel and serial connections carried out at the optimum conditions where the pH value was 9, current density was approximately 15 A/m 2 , and electrolysis time was 2 min resulted in 100% SS removal. Removal efficiencies of EC process for SS with monopolar Fe electrodes in parallel and serial connection were found to be 99.86% and 99.94%, respectively. Optimum parameters for monopolar Fe electrodes in both of the connection types were found to be for pH value as 8, for electrolysis time as 2 min. The optimum current density value for Fe electrodes used in serial and parallel connections was also obtained at 10 and 20 A/m 2 , respectively. Based on the results obtained, it was found that EC process running with each type of the electrodes and the connections was highly effective for the removal of SS and turbidity from marble processing wastewaters, and that operating costs with monopolar Al electrodes in parallel connection were the cheapest than that of the serial connection and all the configurations for Fe electrode.

  1. Removal of suspended solids and turbidity from marble processing wastewaters by electrocoagulation: comparison of electrode materials and electrode connection systems.

    Science.gov (United States)

    Solak, Murat; Kiliç, Mehmet; Hüseyin, Yazici; Sencan, Aziz

    2009-12-15

    In this study, removal of suspended solids (SS) and turbidity from marble processing wastewaters by electrocoagulation (EC) process were investigated by using aluminium (Al) and iron (Fe) electrodes which were run in serial and parallel connection systems. To remove these pollutants from the marble processing wastewater, an EC reactor including monopolar electrodes (Al/Fe) in parallel and serial connection system, was utilized. Optimization of differential operation parameters such as pH, current density, and electrolysis time on SS and turbidity removal were determined in this way. EC process with monopolar Al electrodes in parallel and serial connections carried out at the optimum conditions where the pH value was 9, current density was approximately 15 A/m(2), and electrolysis time was 2 min resulted in 100% SS removal. Removal efficiencies of EC process for SS with monopolar Fe electrodes in parallel and serial connection were found to be 99.86% and 99.94%, respectively. Optimum parameters for monopolar Fe electrodes in both of the connection types were found to be for pH value as 8, for electrolysis time as 2 min. The optimum current density value for Fe electrodes used in serial and parallel connections was also obtained at 10 and 20 A/m(2), respectively. Based on the results obtained, it was found that EC process running with each type of the electrodes and the connections was highly effective for the removal of SS and turbidity from marble processing wastewaters, and that operating costs with monopolar Al electrodes in parallel connection were the cheapest than that of the serial connection and all the configurations for Fe electrode.

  2. Grid-connected integrated community energy system. Phase II, Stage 1, final report. Conceptual design: pyrolysis and waste management systems

    Energy Technology Data Exchange (ETDEWEB)

    1978-03-08

    The University of Minnesota is studying and planning a grid-connected integrated community energy system to include disposal of wastes from health centers and utilizing the heat generated. Following initial definition of the 7-county metropolitan region for which the solid waste management system is to be planned, information is then necessary about the nature of the waste generated within this region. Estimates of the quantities generated, generation rates, and properties of the waste to be collected and disposed of are required in order to determine the appropriate size and capacity of the system. These estimates are designated and subsequently referred to as ''system input''. Institutional information is also necessary in designing the planned system, to be compatible with existing institutional operations and procedures, or to offer a minimum amount of problems to the participating institution in the region. Initial considerations of health care institutions generating solid waste within the defined region are made on a comprehensive basis without any attempt to select out or include feasible candidate institutions, or institutional categories. As the study progresses, various criteria are used in selecting potential candidate institutional categories and institutions within the 7-county region as offering the most feasible solid waste system input to be successfully developed into a centralized program; however, it is hoped that such a system if developed could be maintained for the entire 7-county region, and remain comprehensive to the entire health care industry. (MCW)

  3. Strategic rigidity and foresight for technology adoption among electric utilities

    International Nuclear Information System (INIS)

    Shah, Arsalan Nisar; Palacios, Miguel; Ruiz, Felipe

    2013-01-01

    The variation in the adoption of a technology as a major source of competitive advantage has been attributed to the wide-ranging strategic foresight and the integrative capability of a firm. These possible areas of competitive advantage can exist in the periphery of the firm's strategic vision and can get easily blurred as a result of rigidness and can permeate in the decision-making process of the firm. This article explores how electric utility firms with a renewable energy portfolio can become strategically rigid in terms of adoption of newer technologies. The reluctance or delay in the adoption of new technology can be characterized as strategic rigidness, brought upon as a result of a firm's core competence or core capability in the other, more conventional technology arrangement. This paper explores the implications of such rigidness on the performance of a firm and consequently on the energy eco-system. The paper substantiates the results by emphasizing the case of Iberdrola S.A., an incumbent firm as a wind energy developer and its adoption decision behavior. We illustrate that the very routines that create competitive advantage for firms in the electric utility industry are vulnerable as they might also develop as sources of competitive disadvantage, when firms confront environmental change and uncertainty. - Highlights: • Present a firm-level perspective on technology adoption behavior among electric utilities. • Firms with mature technology can become rigid towards newer technologies. • Case study analysis of a major electric utility firm. • Implications of ‘technology rigidness’ on the energy eco-system

  4. Resting-state functional connectivity assessed with two diffuse optical tomographic systems.

    Science.gov (United States)

    Niu, Haijing; Khadka, Sabin; Tian, Fenghua; Lin, Zi-Jing; Lu, Chunming; Zhu, Chaozhe; Liu, Hanli

    2011-04-01

    Functional near-infrared spectroscopy (fNIRS) is recently utilized as a new approach to assess resting-state functional connectivity (RSFC) in the human brain. For any new technique or new methodology, it is necessary to be able to replicate similar experiments using different instruments in order to establish its liability and reproducibility. We apply two different diffuse optical tomographic (DOT) systems (i.e., DYNOT and CW5), with various probe arrangements to evaluate RSFC in the sensorimotor cortex by utilizing a previously published experimental protocol and seed-based correlation analysis. Our results exhibit similar spatial patterns and strengths in RSFC between the bilateral motor cortexes. The consistent observations are obtained from both DYNOT and CW5 systems, and are also in good agreement with the previous fNIRS study. Overall, we demonstrate that the fNIRS-based RSFC is reproducible by various DOT imaging systems among different research groups, enhancing the confidence of neuroscience researchers and clinicians to utilize fNIRS for future applications.

  5. A Proposal of Client Application Architecture using Loosely Coupled Component Connection Method in Banking Branch System

    Science.gov (United States)

    Someya, Harushi; Mori, Yuichi; Abe, Masahiro; Machida, Isamu; Hasegawa, Atsushi; Yoshie, Osamu

    Due to the deregulation of financial industry, the branches in banking industry need to shift to the sales-oriented bases from the operation-oriented bases. For corresponding to this movement, new banking branch systems are being developed. It is the main characteristics of new systems that we bring the form operations that have traditionally been performed at each branch into the centralized operation center for the purpose of rationalization and efficiency of the form operations. The branches treat a wide variety of forms. The forms can be described by common items in many cases, but the items include the different business logic and each form has the different relation among the items. And there is a need to develop the client application by user oneself. Consequently the challenge is to arrange the development environment that is high reusable, easy customizable and user developable. We propose a client application architecture that has a loosely coupled component connection method, and allows developing the applications by only describing the screen configurations and their transitions in XML documents. By adopting our architecture, we developed client applications of the centralized operation center for the latest banking branch system. Our experiments demonstrate good performances.

  6. Techno-economic feasibility analysis of 1 MW photovoltaic grid connected system in Oman

    Directory of Open Access Journals (Sweden)

    Hussein A. Kazem

    2017-09-01

    Full Text Available Solar photovoltaic panels (PV face many challenges in the Sultanate of Oman. These challenges include costs, policy and technical development. With the growing needs of the Sultanate in the energy sector, Grid Connected PV (GCPV system could help in reducing peak load demand and offer an alternative energy source. This study aims to numerically discover the optimal configuration for a 1 MW GCPV plant in Adam city. Real time data, on hour-by-hour basis, from the location are used to ensure highest accuracy. The simulation not only is set for technical evaluation but economic as well. Investment in GCPV technology needs a bigger push both by research, development and policy. The assessment results show that the PV technology investment is very promising in this site whereas the annual yield factor of the system is 1875.1 kW h/kW p. Meanwhile, the capacity factor of the proposed system is 21.7%. The cost of energy found for the plant is around 0.2258 USD/kW h which is economically feasible and shows great promise.

  7. The effect of seasonal variation on the performances of grid connected photovoltaic system in southern of Algeria

    Science.gov (United States)

    Zaghba, L.; Khennane, M.; Terki, N.; Borni, A.; Bouchakour, A.; Fezzani, A.; Mahamed, I. Hadj; Oudjana, S. H.

    2017-02-01

    This paper presents modeling, simulation, and analysis evaluation of the grid-connected PV generation system performance under MATLAB/Simulink. The objective is to study the effect of seasonal variation on the performances of grid connected photovoltaic system in southern of Algeria. This system works with a power converter. This converter allows the connection to the network and extracts maximum power from photovoltaic panels with the MPPT algorithm based on robust neuro-fuzzy sliding approach. The photovoltaic energy produced by the PV generator will be completely injected on the network. Simulation results show that the system controlled by the neuro-fuzzy sliding adapts to changing external disturbances and show their effectiveness not only for continued maximum power point but also for response time and stability.

  8. Modeling and Simulation for an 8 kW Three-Phase Grid-Connected Photo-Voltaic Power System

    Science.gov (United States)

    Cen, Zhaohui

    2017-09-01

    Gird-connected Photo-Voltaic (PV) systems rated as 5-10 kW level have advantages of scalability and energy-saving, so they are very typical for small-scale household solar applications. In this paper, an 8 kW three-phase grid-connected PV system model is proposed and studied. In this high-fidelity model, some basic PV system components such as solar panels, DC-DC converters, DC-AC inverters and three-phase utility grids are mathematically modelled and organized as a complete simulation model. Also, an overall power controller with Maximum Power Point Control (MPPT) is proposed to achieve both high-efficiency for solar energy harvesting and grid-connection stability. Finally, simulation results demonstrate the effectiveness of the PV system model and the proposed controller, and power quality issues are discussed.

  9. Modeling and Simulation for an 8 kW Three-Phase Grid-Connected Photo-Voltaic Power System

    Directory of Open Access Journals (Sweden)

    Cen Zhaohui

    2017-09-01

    Full Text Available Gird-connected Photo-Voltaic (PV systems rated as 5-10 kW level have advantages of scalability and energy-saving, so they are very typical for small-scale household solar applications. In this paper, an 8 kW three-phase grid-connected PV system model is proposed and studied. In this high-fidelity model, some basic PV system components such as solar panels, DC-DC converters, DC-AC inverters and three-phase utility grids are mathematically modelled and organized as a complete simulation model. Also, an overall power controller with Maximum Power Point Control (MPPT is proposed to achieve both high-efficiency for solar energy harvesting and grid-connection stability. Finally, simulation results demonstrate the effectiveness of the PV system model and the proposed controller, and power quality issues are discussed.

  10. Connecting the immune system, systemic chronic inflammation and the gut microbiome: The role of sex.

    Science.gov (United States)

    Rizzetto, Lisa; Fava, Francesca; Tuohy, Kieran M; Selmi, Carlo

    2018-05-31

    Unresolved low grade systemic inflammation represents the underlying pathological mechanism driving immune and metabolic pathways involved in autoimmune diseases (AID). Mechanistic studies in animal models of AID and observational studies in patients have found alterations in gut microbiota communities and their metabolites, suggesting a microbial contribution to the onset or progression of AID. The gut microbiota and its metabolites have been shown to influence immune functions and immune homeostasis both within the gut and systematically. Microbial derived-short chain fatty acid (SCFA) and bio-transformed bile acid (BA) have been shown to influence the immune system acting as ligands specific cell signaling receptors like GPRCs, TGR5 and FXR, or via epigenetic processes. Similarly, intestinal permeability (leaky gut) and bacterial translocation are important contributors to chronic systemic inflammation and, without repair of the intestinal barrier, might represent a continuous inflammatory stimulus capable of triggering autoimmune processes. Recent studies indicate gender-specific differences in immunity, with the gut microbiota shaping and being concomitantly shaped by the hormonal milieu governing differences between the sexes. A bi-directional cross-talk between microbiota and the endocrine system is emerging with bacteria being able to produce hormones (e.g. serotonin, dopamine and somatostatine), respond to host hormones (e.g. estrogens) and regulate host hormones' homeostasis (e.g by inhibiting gene prolactin transcription or converting glucocorticoids to androgens). We review herein how gut microbiota and its metabolites regulate immune function, intestinal permeability and possibly AID pathological processes. Further, we describe the dysbiosis within the gut microbiota observed in different AID and speculate how restoring gut microbiota composition and its regulatory metabolites by dietary intervention including prebiotics and probiotics could help in

  11. Modeling and Simulation for an 8 kW Three-Phase Grid-Connected Photo-Voltaic Power System

    OpenAIRE

    Cen Zhaohui

    2017-01-01

    Gird-connected Photo-Voltaic (PV) systems rated as 5-10 kW level have advantages of scalability and energy-saving, so they are very typical for small-scale household solar applications. In this paper, an 8 kW three-phase grid-connected PV system model is proposed and studied. In this high-fidelity model, some basic PV system components such as solar panels, DC-DC converters, DC-AC inverters and three-phase utility grids are mathematically modelled and organized as a complete simulation model....

  12. Rigid pricing and rationally inattentive consumer

    Czech Academy of Sciences Publication Activity Database

    Matějka, Filip

    158 B, July (2015), s. 656-678 ISSN 0022-0531 Institutional support: PRVOUK-P23 Keywords : rational inattention * imperfect information * nominal rigidity Subject RIV: AH - Economics Impact factor: 1.097, year: 2015

  13. Rigid pricing and rationally inattentive consumer

    Czech Academy of Sciences Publication Activity Database

    Matějka, Filip

    158 B, July (2015), s. 656-678 ISSN 0022-0531 Institutional support: RVO:67985998 Keywords : rational inattention * imperfect information * nominal rigidity Subject RIV: AH - Economics Impact factor: 1.097, year: 2015

  14. Crack identification for rigid pavements using unmanned aerial vehicles

    Science.gov (United States)

    Bahaddin Ersoz, Ahmet; Pekcan, Onur; Teke, Turker

    2017-09-01

    Pavement condition assessment is an essential piece of modern pavement management systems as rehabilitation strategies are planned based upon its outcomes. For proper evaluation of existing pavements, they must be continuously and effectively monitored using practical means. Conventionally, truck-based pavement monitoring systems have been in-use in assessing the remaining life of in-service pavements. Although such systems produce accurate results, their use can be expensive and data processing can be time consuming, which make them infeasible considering the demand for quick pavement evaluation. To overcome such problems, Unmanned Aerial Vehicles (UAVs) can be used as an alternative as they are relatively cheaper and easier-to-use. In this study, we propose a UAV based pavement crack identification system for monitoring rigid pavements’ existing conditions. The system consists of recently introduced image processing algorithms used together with conventional machine learning techniques, both of which are used to perform detection of cracks on rigid pavements’ surface and their classification. Through image processing, the distinct features of labelled crack bodies are first obtained from the UAV based images and then used for training of a Support Vector Machine (SVM) model. The performance of the developed SVM model was assessed with a field study performed along a rigid pavement exposed to low traffic and serious temperature changes. Available cracks were classified using the UAV based system and obtained results indicate it ensures a good alternative solution for pavement monitoring applications.

  15. Multiple fMRI system-level baseline connectivity is disrupted in patients with consciousness alterations.

    Science.gov (United States)

    Demertzi, Athena; Gómez, Francisco; Crone, Julia Sophia; Vanhaudenhuyse, Audrey; Tshibanda, Luaba; Noirhomme, Quentin; Thonnard, Marie; Charland-Verville, Vanessa; Kirsch, Murielle; Laureys, Steven; Soddu, Andrea

    2014-03-01

    In healthy conditions, group-level fMRI resting state analyses identify ten resting state networks (RSNs) of cognitive relevance. Here, we aim to assess the ten-network model in severely brain-injured patients suffering from disorders of consciousness and to identify those networks which will be most relevant to discriminate between patients and healthy subjects. 300 fMRI volumes were obtained in 27 healthy controls and 53 patients in minimally conscious state (MCS), vegetative state/unresponsive wakefulness syndrome (VS/UWS) and coma. Independent component analysis (ICA) reduced data dimensionality. The ten networks were identified by means of a multiple template-matching procedure and were tested on neuronality properties (neuronal vs non-neuronal) in a data-driven way. Univariate analyses detected between-group differences in networks' neuronal properties and estimated voxel-wise functional connectivity in the networks, which were significantly less identifiable in patients. A nearest-neighbor "clinical" classifier was used to determine the networks with high between-group discriminative accuracy. Healthy controls were characterized by more neuronal components compared to patients in VS/UWS and in coma. Compared to healthy controls, fewer patients in MCS and VS/UWS showed components of neuronal origin for the left executive control network, default mode network (DMN), auditory, and right executive control network. The "clinical" classifier indicated the DMN and auditory network with the highest accuracy (85.3%) in discriminating patients from healthy subjects. FMRI multiple-network resting state connectivity is disrupted in severely brain-injured patients suffering from disorders of consciousness. When performing ICA, multiple-network testing and control for neuronal properties of the identified RSNs can advance fMRI system-level characterization. Automatic data-driven patient classification is the first step towards future single-subject objective diagnostics

  16. Chronic toxicity risk after radiotherapy for patients with systemic sclerosis (systemic scleroderma) or systemic lupus erythematosus: Association with connective tissue disorder severity

    International Nuclear Information System (INIS)

    Gold, Douglas G.; Miller, Robert C.; Pinn, Melva E.; Osborn, Thomas G.; Petersen, Ivy A.; Brown, Paul D.

    2008-01-01

    No method reliably identifies which patients with connective tissue disorders are at greatest risk of radiotherapy-related complications. Building on our prior experience, we postulated that disease severity, as measured by the number of organ systems involved, may predict chronic radiation toxicity risk

  17. [Oral rehabilitation with metalloceramic restorations in patients with non-differentiated systemic connective tissue dysplasia].

    Science.gov (United States)

    Stafeev, А А

    2015-01-01

    False formation of connective tissues have a great influence on structure and function of organs and tissues of the human body. In prosthodontics, the changes in connective tissues greatly occur during clinical stages of preparing metal ceramic dentures. The algorithm of treatment patients with connective tissue dysplasia during metal ceramic dentures was developed and introduced into practical dentistry based on studying the morphology and functionality of dentition and clinical experience.

  18. Supervision and control of grid connected PV-Storage systems with the five level diode clamped inverter

    International Nuclear Information System (INIS)

    Himour, Kamal; Ghedamsi, Kaci; Berkouk, El Madjid

    2014-01-01

    Highlights: • Use of battery bank in grid connection photovoltaic system to ensure the energetic autonomy of the system. • Improve the quality of energy by the use of five-level inverter in a grid connection PV generation system. • Control of inverter by fast and simplified space vector pulse width modulation. • Control and supervision of active and reactive power in the grid. - Abstract: This paper aimed to evaluate the use of photovoltaic-battery storage systems to supply electric power in the distribution grid through a multilevel inverter. The proposed system is composed by four PV generators with MPPT (P and O) control, four battery storage systems connected to each capacitor of the DC link and a five level diode clamped inverter connected to the grid by a traditional three phase transformer. The proposed control has a hierarchical structure with both a grid side control level to regulate the power and the current injected to the grid and four input side regulation units. The system operator controls the power production of the four PV generators by sending out reference power signals to each input side regulation unit, the input side regulation units regulate the voltage of each capacitor of the DC link, regulate the voltage and the state of charge of each battery storage system

  19. Grid connected integrated community energy system. Phase II: final stage 2 report. Outline specifications of cogeneration plant; continued

    Energy Technology Data Exchange (ETDEWEB)

    1978-03-22

    Specifications are presented for the electrical equipment, site preparation, building construction and mechanical systems for a dual-purpose power plant to be located on the University of Minnesota campus. This power plant will supply steam and electrical power to a grid-connected Integrated Community Energy System. (LCL)

  20. Performance and economic analysis of a 27 kW grid-connected photovoltaic system in Suriname

    NARCIS (Netherlands)

    Raghoebarsing, Amrita; Kalpoe, Anand

    2017-01-01

    The performance of a grid-connected photovoltaic (PV) system, under the Surinamese weather conditions, is monitored and reported. A measurement and data-logging system provides inputs for the calculation of selected standard key performance indicators (KPI). Calculated KPI's are compared to expected